Geping Yin

Localized degradation and faults of lithium-ion batteries critically affect their lifespan and safety. Magnetic field distribution of batteries is effective for non-destructive detection, yet their broader application is hindered by limited data availability. In this study, A novel three-dimensional electrochemical-magnetic field model is proposed to address this critical issue through the magnetic field characteristics of batteries. The model comprehensively investigates the distinctive magnetic field distribution associated with various anomalies, including tab fractures, current collector fractures, internal short circuit (ISC), electrolyte drying-out, and electrode materials deactivation. In this way, the relative magnetic field changes and the magnetic field gradient distribution of different degradation patterns and faults can be extracted for non-destructive detection of subtle localized anomalies. The method offers solutions for classifying …

Forecasting the battery performance accurately in the ultra-early stage can avoid safety incidents, analyze degradation patterns, and prolong battery cycle life, which is crucially essential for battery management. In this work, a mechanism and data-driven fusion model is developed to predict charging capacity and energy curves over the full life cycle of batteries in the case of only knowing the planned cycling protocol without any usage history. The proposed method can achieve accurate and robust prediction of three types of batteries under different working conditions and ambient temperatures with the root-mean-square error (RMSE) of 73.7, 100.9, and 45 mAh. The maximum charging capacity and energy trajectory can be extracted further. Moreover, the proposed method can also detect battery faults without setting a safety threshold in advance due to the inconsistency of the voltage and capacity evolutions of …

TiNb2O7 (TNO) has emerged as a highly potential power-type anodes for extremely fast-charging batteries. Nevertheless, the inherent electron conductivity and crystalline stability of TNO, limiting its actual capacity. Herein, a TNO anode doped by highly oxidized state ions is designed for regulating unit cell volume expansion, oxygen vacancies generation and charge mobility through induced Nb-O bond distortion. The Ce0.01-TNO electrode shows a high discharge capacity of 181 mAh·g−1 at 20 C after 1000 cycles. Meanwhile, the density functional theory simulations demonstrate that decreased ion-diffusion barrier and increased electronic conductivity are obtained by narrowing the bandgap and introducing impurity bands induced by Ce doping. This work provides an effective strategy to enhance the electrochemical performance of TiNb2O7, making a guideline to construct fast-charging batteries with a …

TiNb2O7 has garnered attention as promising anode materials due to its remarkable cycling durability and rate capability, but its practical applications are currently hampered by the sluggish ion/electron kinetics. Herein, we propose a bimetallic synergistic strategy to enhance ionic and electronic transport kinetics, improving electrochemical performance. DFT calculation results further confirm the synergistic effect of Zn and Nb can increase the lattice parameters, promote Li+ diffusion, and enhance electronic conductivity. Benefiting from this, the Zn0.02Ti0.94Nb2.04O7 exhibits excellent cycling stability (a capacity loss of 0.02 % per cycle over 1000 cycles). An Ah-level pouch cell presents potential application with an impressive cycle lifespan, corresponding to an ultra-high retention ratio of 88.6 % (2.34 Ah) over 2700 cycles. Importantly, in-situ XRD and Nano-CT techniques elucidate the positive impact of the …

Elucidating how the local strain environment of single atoms affects their impact on a sluggish acidic oxygen reduction reaction (ORR) is important for the design and construction of highly active electrocatalysts. Here, we report that the atomic strain geometry of Fe single sites is exclusively regulated by the communicative effects of dual atoms. Theoretical analysis reveals that Fe-Ru dual atoms in a moderate strain environment achieve the lowest Gibbs free energy barrier during an ORR. Impressively, FeRu-N-C with an FeRuN8 moiety exhibits the highest acidic ORR performance, with a half-wave potential (E1/2) of 0.860 V and only a 17-mV loss in E1/2 after 50,000 potential cycles. Operando characterization and electronic configuration analysis demonstrate that moderately strained Fe sites promote hydrogenation desorption of (oxy-)hydroxyl by enabling more electrons to occupy antibonding orbitals. This study …

Quasi‐solid‐state lithium metal batteries (QSSLMBs) necessitate stable electro‐electrolyte interfaces to ensure reliable stationary power supply, thereby placing significant emphasis on the development of polymer electrolytes with high and uniform conductivity. However, while preparing the polymer electrolytes, the uncontrolled radical polymerization process of polymer electrolytes often leads to localized phase agglomeration, resulting in inhomogeneous physiochemical properties. In this study, a method is proposed to regulate the micro‐phase structure, aiming to substantially enhance the homogeneity of physiochemical properties, specifically the ionic conductivity, through the optimization of organic monomer polymerization behavior. This proposed polymer electrolyte determines enhanced reaction kinetics and reactivity at the interfaces, thereby effectively regulating the Li plating/stripping behavior and …

The high voltage stability (> 5.5 V) makes sulfolane (SL) an excellent electrolyte solvent candidate for high specific energy lithium-ion batteries. However, the stable solid electrolyte interphase (SEI) cannot be generated on the surface of graphite particles with SL, limiting its application. To solve the interface incompatibility, we introduce fluoroethylene carbonate (FEC) and lithium nitrate (LiNO3) in SL-based electrolyte for constructing an inorganic-rich SEI on graphite. The comprehensive characterizations and simulations demonstrate that combined effect of additives facilitates the formation of additive-derived LiF-Li3N enhanced inorganic-rich SEI. The proposed electrolyte shows stable cycling performances with 324.89 mAh/g and 97.93 % after 50 cycles in Li/graphite half-cells, compared with the capacity of 24.54 mAh/g and the capacity retention of 19.4 % in SL-without additives. Importantly, the electrolyte system …

Li4Ti5O12 (LTO) with great promising anode material for Li-ion batteries (LIBs) has attracted extensive attention, while the large-scale application is hampered owing to the low electronic conductivity and Li+ diffusion coefficient. Herein, the carbon-coated LTO with a unique soccerene-like structure is constructed to simultaneously improve the electron and ion transport by the simple and scalable soft template method. The as-obtained LTO/C material exhibits unique soccerene-like morphology with a large specific surface area and abundant open channels, which can endow the rapid diffusion for Li+ and electrons, and provide more favorable paths for penetration of the electrolyte. Besides, the carbon layer (about 3 nm) on the surface of LTO material can improve the electronic conductivity. Therefore, the LTO/C shows superior electrochemical performance, especially at high-rate discharging.The composite delivers …

Rechargeable zinc batteries (RZBs) have been considered as promising candidates for next-generation large-scale energy storage systems due to the high theoretical capacity (820 mAh g−1), environmental friendliness and sustainability of zinc metal anode. Nevertheless, the practical realization of secondary zinc batteries were impeded by the dendrite issues and consequent poor cycle stability. Here, the Ga-In-Sn-Zn solid-liquid composite (SLC) was proposed to construct SLC-2 electrode by a facile and easily scalable painting strategy. The experimental results and theoretical calculations validated that the solid phase InSn4 in the designed electrode shows good adsorbing ability and lower migration energy barrier of Zn ions, and the electrochemically inert Ga-In liquid component can release the stress changes of the composite electrode, realizing a smooth and dendrite-free Zn deposition. The SLC-2 anode …

The high operational capability of fast-charging lithium-ion batteries (LIBs) at low temperatures (<−30°C) is essential for frequency regulation and peak-load shifting of power grids in cold regions. However, the low-temperature performance is seriously plagued by the sluggish Li+ diffusion and high-voltage polarization. Herein, the heterostructure-induced built-in electric field is constructed by selected nitriding of TiNb2O7, which demonstrates high accessibility for accelerated low-temperature dynamics. The introduced charged phase-junction interface enables promoted Li+ diffusion rates, enhanced Li+ adsorption, and reduced lattice strains. The mosaic TiNb2O7/TiNbN2 heterostructure displays an outstanding specific capacity of 241.5 mA h g−1 at −30°C, corresponding to 89% retention compared with that at 25°C. It even delivers a high-capacity retention of 96% at a 5C rate after approximately 1,000 cycles at −30 …

The two-electron oxygen reduction reaction in acid is highly attractive to produce H2O2, a commodity chemical vital in various industry and household scenarios, which is still hindered by the sluggish reaction kinetics. Herein, both density function theory calculation and in-situ characterization demonstrate that in dual-atom CoIn catalyst, O-affinitive In atom triggers the favorable and stable adsorption of hydroxyl, which effectively optimizes the adsorption of OOH on neighboring Co. As a result, the oxygen reduction on Co atoms shifts to two-electron pathway for efficient H2O2 production in acid. The H2O2 partial current density reaches 1.92 mA cm−2 at 0.65 V in the rotating ring-disk electrode test, while the H2O2 production rate is as high as 9.68 mol g−1 h−1 in the three-phase flow cell. Additionally, the CoIn-N-C presents excellent stability during the long-term operation, verifying the practicability of the CoIn-N …

High-performance sodium-ion batteries (SIBs) require not only non-aqueous electrolytes with high ion conductivity but also high interfacial compatibility with both electrodes. Ether-based electrolytes are considered one of the most promising electrolyte systems for SIBs due to the advantages of high reduction stability and weakly desolvating power. However, conventional ether-based electrolytes are easy to decompose and deteriorate on the cathode/electrolyte interface under high voltage, which greatly restricts their practical application in SIBs. Herein, a novel and effective interfacial stabilization strategy is proposed and systemically investigated. A homogeneous and compact cathode electrolyte interphase (CEI) film rich in fluorides and borides can be successfully constructed on the cathode surface by pre-cycling of NVP@C cathode in the NaODFB-DEGDME electrolyte. The ODFB anion-derived CEI film can …

Si-based anode materials have become the most popular candidate in next generation high-specific energy lithium-ions batteries owing to the advantages of high theoretical capacity, low operation potential, environmental friendliness, and low cost. However, the huge volume changes of Si-based anode during the charging and discharging process results in unstable solid electrolyte interphase (SEI) films and poor cycling performance. Here, 2-isocyanatoethyl methacrylate (IEM) and fluoroethylene carbonate (FEC) are used as functional electrolyte additives to constructing stable and durable inorganic-organic composite SEI films on the surface of Si@Graphene (Si/G) anode. The composite SEI film can tolerate the volume change of Si/G anode. As a result, the Si/G anode shows enhanced initial Coulombic efficiency (ICE), cycling stability and rate capability. Specifically, the ICE of Li||Si/G cell can reach 90%, and …

Silicon oxide (SiOx), consisting of nanosized Si crystallites and oxide matrix (SiOy, y near 2), is regarded as one of the most promising anode materials for next-generation high energy density lithium-ion batteries (LIBs). Commonly, modulating oxygen content and surface chemistry are favorable to the lithium ions storage performances of SiOx anode. Here, an AlCl3–MgSO4 assisted low-temperature (250 °C) etching technique is adopted to modify the commercial micron-sized SiOx anode, this novel modification method tunes the O/Si ratio on the surface of SiOx. Impressively, the modified SiOx anode exhibits a high reversible capacity of 480 mAh g−1 at 1A g−1 after 200 cycles and good rate capability of above 110 mAh g−1 at 10 A g−1. This work provides a simple and feasible modification strategy to the development of high performance SiOx anode.

The local coordination environment of catalytical moieties directly determines the performance of electrochemical energy storage and conversion devices, such as Li–O2 batteries (LOBs) cathode. However, understanding how the coordinative structure affects the performance, especially for non‐metal system, is still insufficient. Herein, a strategy that introduces S‐anion to tailor the electronic structure of nitrogen–carbon catalyst (SNC) is proposed to improve the LOBs performance. This study unveils that the introduced S‐anion effectively manipulates the p‐band center of pyridinic‐N moiety, substantially reducing the battery overpotential by accelerating the generation and decomposition of intermediate products Li1–3O4. The lower adsorption energy of discharging product Li2O2 on NS pair accounts for the long‐term cyclic stability by exposing the high active area under operation condition. This work …

Nitrile electrolytes have attracted extensive attention for achieving high-voltage lithium metal batteries. However, the poor compatibility of nitrile electrolyte with Li anode remains a huge challenge owing to severe side reactions. Herein, changing concentration of LiTFSI in succinonitrile (SN) is proposed to improve interface compatibility by regulating the solvation structure. The higher coordination number (1.3) of TFSI− in high concentration electrolytes results in a LiF-rich SEI film, accounting for the superior performance of LiNi0.8Co0.1Mn0.1O2|Li cell with negligible capacity fade after 100 cycles at 0.5 C. Density functional theory (DFT) suggests that the solvation structure with a high coordination number of TFSI− towards Li+ leads to a reduced Lowest Unoccupied Molecular Orbital (LUMO) energy level, which promotes the decomposition of TFSI− to form LiF-rich film. Also, a reduced decomposition energy barrier …

A typical battery electrode is composed of polydisperse particles and porous composite binder domains. The arrangement of these constituent phases into complex mesoscopic structures plays a significant impact on electrochemical reaction and mechanical response, ultimately limiting macroscale battery performance. Limited by the spatial and temporal resolution of current characterization techniques, bridging digital modeling-assisted electrochemical simulation techniques can fully reveal the complicated mesoscale mechanisms in electrodes. The exploitation of digital twin-driven electrode models, visualization of physical and electrochemical behavior has become a prospect with the development of computing technology. This review summarizes the previous and current research focused on the digital model-derived to investigate the performance and the design of electrodes at mesoscale. The typical cases of …

Solid-state batteries (SSBs) have been widely considered as the most promising technology for next-generation energy storage systems. Among the anode candidates for SSBs, silicon (Si)-based materials have received extensive attention due to their advantages of low potential, high specific capacity and abundant resource. However, Si-based anodes undergo significant volume changes during repeated charging and discharging process, leading to irreversible degradation of electrode/electrolyte interface and rapid capacity fading of SSBs. Therefore, the development of Si-based SSBs is still limited to laboratory level. In this review, we systematically summarized the research advances of Si-based SSBs from the aspects of the design principle of electrodes structure, the selection of solid-state electrolytes and the corresponding interfacial optimization strategies, failure mechanisms of electrochemical …

Single-atom catalysts have been paid more attention to improving sluggish reaction kinetics and anchoring polysulfide for lithium–sulfur (Li–S) batteries. It has been demonstrated that d-block single-atom elements in the fourth period can chemically interact with the local environment, leading to effective adsorption and catalytic activity toward lithium polysulfides. Enlightened by theoretical screening, for the first time, we design novel single-atom Nb catalysts toward improved sulfur immobilization and catalyzation. Calculations reveal that Nb–N4 active moiety possesses abundant unfilled antibonding orbitals, which promotes d-p hybridization and enhances anchoring capability toward lithium polysulfides via a “trapping–coupling–conversion” mechanism. The Nb–SAs@NC cell exhibits a high capacity retention of over 85% after 1000 cycles, a superior rate performance of 740 mA h g–1 at 7 C, and a competitive areal …

Chromium oxides (Cr8O21 and Cr2O5) were synthesized by pyrolysis of CrO3 at different temperatures (325 °C, 350 °C and 375 °C) and employed as promising cathode materials in rechargeable lithium batteries. The material prepared at 325 °C with a heating rate of 5 °C /min in air for 2 h delivers the high specific capacity of 365 mAh/g and energy density of 1108 Wh/kg at a current density of 10 mA/g. Even at a high current density of 100 mA/g, the material shows the initial discharge capacity of 298 mAh/g and a relatively high capacity retention of 56.4% after 50 cycles. The LiCrO2 is formed during the first discharge process, and its reversibility during lithiation and delithiation process is verified by the structure and chromium valence evolution during cycling.

Fe single atoms and N co‐doped carbon nanomaterials (Fe‐N‐C) are the most promising oxygen reduction reaction (ORR) catalysts to replace platinum group metals. However, high‐activity Fe single‐atom catalysts suffer from poor stability owing to the low graphitization degree. Here, an effective phase‐transition strategy is reported to enhance the stability of Fe‐N‐C catalysts by inducing increased degree of graphitization and incorporation of Fe nanoparticles encapsulated by graphitic carbon layer without sacrificing activity. Remarkably, the resulted Fe@Fe‐N‐C catalysts achieved excellent ORR activity (E1/2 = 0.829 V) and stability (19 mV loss after 30K cycles) in acid media. Density functional theory (DFT) calculations agree with experimental phenomena that additional Fe nanoparticles not only favor to the activation of O2 by tailoring d‐band center position but also inhibit the demetallization of Fe active …

Rational design of platinum group metal (PGM)-free catalysts, e.g., M−N−C catalysts, with well-defined structure is highly essential to replace the conventional PGM-based catalysts towards oxygen reduction reaction (ORR), which, however, is still challenging. Particularly, extra nitrogen plays an important role in the ORR performance of M−N−C but the mechanism remains unclear. In this work, a facile modulation strategy based on solvent effect is proposed to tailor nitrogen dopants in the metal organic frameworks (MOFs)-derived Co-N-C catalysts. DFT calculations reveal that the synergy of pyridinic-N and CoNx significantly accelerate the ORR. Reasonably, the optimized Co-N-C catalyst shows superior onset potential (Eonset) of 0.915 V and half-wave potential (E1/2) of 0.785 V toward ORR. This work may pave an avenue for the precise construction of active moieties in large-scale preparation of PGM-free ORR …

Severe mechanical fracture and unstable interphase, associated with the large volumetric expansion/contraction, significantly hinder the application of high-capacity SiOx materials in lithium-ion batteries. Herein, we report the design and facile synthesis of a layer stacked SiOx microparticle (LS-SiOx) material, which presents a stacking structure of SiOx layers with abundant disconnected interstices. This LS-SiOx microparticle can effectively accommodate the volume expansion, while ensuring negligible particle expansion. More importantly, the interstices within SiOx microparticle are disconnected from each other, which efficiently prevent the electrolyte from infiltration into the interior, achieving stable electrode/electrolyte interface. Accordingly, the LS-SiOx material without any coating delivers ultrahigh average Coulombic efficiency, outstanding cycling stability, and full-cell applicability. Only 6 cycles can attain >99 …

The booming wearable/portable electronic devices industry has stimulated the progress of supporting flexible energy storage devices. Excellent performance of flexible devices not only requires the component units of each device to maintain the original performance under external forces, but also demands the overall device to be flexible in response to external fields. However, flexible energy storage devices inevitably occur mechanical damages (extrusion, impact, vibration)/electrical damages (overcharge, over-discharge, external short circuit) during long-term complex deformation conditions, causing serious performance degradation and safety risks. Inspired by the healing phenomenon of nature, endowing energy storage devices with self-healing capability has become a promising strategy to effectively improve the durability and functionality of devices. Herein, this review systematically summarizes the latest …

High-performance batteries with various functions are highly expected for building a smart system for the next-generation intelligent equipment. Traditional batteries are faced with great challenges such as adaptability to complex stress environments, biocompatibility, and integration with structural components. Energy metabolism and storage systems, in nature, have many advantages of high efficiency, flexibility, precision, controllability, and renewability. Inspired by nature, advanced electrochemical energy storage materials and battery devices have been rationally designed and manufactured along with great breakthroughs in recent years. In this review, we summarize the latest progress in nature-inspired functional battery devices. Specifically, the exploration inspired by nature introduce various behaviors of batteries operated under different stress conditions, including the four basic deformations (bending …

Non-flammable succinonitrile (SN) is a promising plasticizer for lowering the working temperature of poly (ethylene oxide) (PEO)-based solid-state polymer electrolytes. However, its application is greatly impeded by the inherent instability interface toward the Li anode. Here, we report a novel PEO/SN-based composite solid-state electrolyte with a durable interface and high room-temperature ionic conductivity of 6.74×10−4 S cm−1. By taking advantage of cation-assistance between La3+ cation in LLZTO and N atom in SN, reducing the active -Ctriple bondN groups or converting them to less reactive -C = N- groups, preventing the corrosion of lithium anode from SN. As a result, PEO/SN-based electrolyte displays highly stable Li plating/stripping cycling for over 1000 h at 0.1 mA cm−2 at RT. Furthermore, the all-solid-state lithium metal batteries (ASSLBs) based on LiFePO4 cathode deliver admirable cycling stability …

Magnesium batteries are one of the ideal candidates for next-generation battery systems with high energy density and safety. However, the development of compatible non-nucleophilic electrolytes and the passivation of the Mg anode are the primary obstacles that impede their development. Here, a non-nucleophilic electrolyte is proposed through in-situ reactions between AlCl3 + InCl3/TEG (AI-E) electrolyte and Mg anode, which kills two birds with one stone that magnesium salts with the structures of [MgCl·TEG]+ and [MgCl·2TEG]+ are generated and the passive film on Mg anode is converted into solid electrolyte interphase (SEI). Compared with the Mg(TFSI)2 electrolyte, the polarization of the Mg anode in the AI-E electrolyte decreases from 2.0 V to 0.08 V for 400 cycles, and the Mg/S battery with the AI-E electrolyte reaches an improved discharge voltage plateau of 1.12 V for 50 cycles. This work expects to …

Lithium-ion batteries have dominated the markets of portable devices, electric vehicles, and grid storage. However, the increased safety concerns, range anxiety, and the mismatch between charging time and expectations resulted in a severe hampering of their applications in electric vehicles (EVs). This Perspective focuses on the limiting factors and the recent progress of fast-charging lithium-ion batteries. The limiting factors are discussed from the materials, electrolytes, electrodes, cells, packs, systems, charging stations, and safety issues including the potential impact of fast charging on thermal runaway characteristics. Then, performance optimization strategies from multiscales for fast charging are reviewed. In particular, the key to future fast-charging technologies lies in high-voltage charging techniques and advanced thermal management systems. These technologies can achieve both fast charging and …

Macro- and micro-interface instability of SiOx anode caused by its dramatic volume variation during cycling will result in low Coulombic efficiency and rapid capacity degradation. In this work, an organic-inorganic composite interfacial layer rich in benzene ring groups, polyisocyanates, and LiF was obtained on SiOx anode by the introduction of 4-fluorophenyl isocyanate (FPI) and fluoroethylene carbonate (FEC) co-additives in electrolyte. The SiOx anode material shows a capacity retention of 69.2% after 100 cycles at a current density of 1 A g−1 and rate capacity of 523 mA h g−1 at the current density of 3 A g−1, while the SiOx anode cycling in reference electrolyte has almost no capacity.

The inhomogeneous nature of SiOx anode material on the atomic scale directly affects its electrochemical performance. A large irreversible capacity loss at the first cycle severely hinders the applications of SiOx materials in lithium ion batteries. The modification of SiOx by means of high-energy ball-milling and wet alkali chemical reaction can tune the ordering of amorphous silicon and silicon dioxide in SiOx materials, which is beneficial to the activation of nano silicon region and the surficial composition optimization of the lithiated products of SiOx during the first discharge process, and the formed Li2SiO3 phase and the increased O/Si ratio in the surface of SiOx contribute to the improved cyclic performance. This surface regulation approach is quite simple, efficient and suitable for large-scale applications of high-performance SiOx anode material.

Lithium oxalate (Li2C2O4) is an attractive cathode pre-lithiation additive for lithium-ion batteries (LIBs), but its application is hindered by its high decomposition potential (>4.7 V). Due to the liquid–solid synergistic effect of the NaNO2 additive and the LiNi0.83Co0.07Mn0.1O2 (NCM) cathode material, the decomposition efficiency of micro-Li2C2O4 reaches 100% at a low charge cutoff voltage of 4.3 V. Our work boosts the widespread practical application of Li2C2O4 by a simple and promising electrolyte-assisted cathode pre-lithiation strategy.

The fast‐growing development for high‐capacity anodes is undermined by their unsatisfactory rate performance and cycling stability stemming from sluggish ion‐migration speed, poor electronic conductivity, and mechanical degradation induced by the stress accumulation, which greatly hamper practical applications of Na‐ion batteries. Here, a combined experimental and theoretical study on atomic‐thickness (0.6 nm) Co(OH)2 nanosheet with surface defects (2D‐Co(OH)2@D NSs) and large interplanar spacing (0.465 nm) is presented, in which fast ion/electron transport is permitted to boost battery reactions. The mechanical degradation on cycling can be well buffered via tailoring mesopores across the Co(OH)2 nanosheet and an elastic solid–electrolyte interface is established by modulating the electronic structure of the Co(OH)2 surface. The 2D‐Co(OH)2@D NSs exhibit high rate‐capacity (>228 mAh g−1 at …

Gel polymer electrolytes (GPE) are promising next‐generation electrolytes for high‐energy batteries, combining the multiple advantages of liquid and all‐solid‐state electrolytes. Herein, we a synthesized GPE using poly(ethylene glycol)acrylate (PEGDA) in order to understand how the GPE efficiently inhibits lithium dendrite formation and growth. The effects of PEGDA on the solvation shell structure of the lithium ion are investigated using density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations, which are also supported by Raman spectroscopy. The GPE electrolytes with optimal PEGDA concentration exhibit high transference numbers (t =0.72) and ionic conductivity (σ=3.24 mS cm−1). A symmetric lithium ion battery using GPE can be stably cycled for 1200 h in comparison to 320 h in a liquid electrolyte (LE), possibly owing to the high content of LiF (17.9 %) in the solid–electrolyte …

Accurate early detection of internal short circuits (ISCs) is indispensable for safe and reliable application of lithium-ion batteries (LiBs). However, the major challenge is finding a reliable standard to judge whether the battery suffers from ISCs. In this work, a deep learning approach with multi-head attention and a multi-scale hierarchical learning mechanism based on encoder-decoder architecture is developed to accurately forecast voltage and power series. By using the predicted voltage without ISCs as the standard and detecting the consistency of the collected and predicted voltage series, we develop a method to detect ISCs quickly and accurately. In this way, we achieve an average percentage accuracy of 86% on the dataset, including different batteries and the equivalent ISC resistance from 1,000 Ω to 10 Ω, indicating successful application of the ISC detection method.

Silicon based anodes are the most attractive candidates for high energy density lithium-ion batteries (LIBs), but their practical applications are hindered by the large initial lithium loss. Cathode prelithiation is an effective method to mitigate the active lithium loss in silicon-based LIBs. However, a cathode prelithiation method enabling suitable cutoff voltage and less residues still remains challenging. Herein, we demonstrate that soluble additive NaNO2 in carbonate-based electrolyte could efficiently reduce the decomposition voltage of Li2O2 to as low as 4.3 V. The liquid–solid synergistic effect of NaNO2 additive and LiNi0.83Co0.07Mn0.1O2 (NCM) cathode on the Li2O2 decomposition is revealed, which enables the highly efficient cathode prelithiation with remarkable Li2O2 decomposition efficiency of 96.7% at the acceptable cutoff voltage 4.4 V. For the addition for 1 wt% Li2O2, a capacity of 14.85 mAh/g could be …

All-solid-state batteries (ASSBs) have attracted considerable attention due to their theoretically high energy density and safety. However, maintaining intimate interfacial contact at low external pressures remains a challenge, limiting large-scale practical applications. Here, a bottom-up design of all-solid-state electrodes is proposed by minimizing internal stress variation to maintain interfacial transport at low external pressures. Theoretical calculations and synchrotron X-ray techniques reveal that the surface-to-bulk pillar effect alleviates the volumetric strain of the cathode materials at high delithiation, which is favorable for improving the interfacial mechanical and chemical compatibility to create fast ion percolation networks of the electrode. Therefore, the 4.4 V sulfide-based ASSBs retain a high specific capacity (166.7 mAh g–1, 0.2C), good rate performance, and stable cyclability (90.8% retention) at the operating …

The Mg-S battery has great development potential benefiting from its high volume energy density and high-safety. However, it also confronts with two key issues especially when using the Mg(TFSI)2-based electrolyte. One is the poor compatibility between electrolyte and Mg anode, and the other is the poor reversibility of cathode. In this work, an artificial interphase including Zn/ZnCl2/MgZn2/MgCl2 was firstly pre-constructed by replacement reaction of ZnCl2 and Mg, which can reduce Mg plating/stripping overpotential to 0.2 V at 0.1 mA/cm2. Meanwhile, the reversibility of cathode can be improved by using copper powders as additive in sulfur/carbon composite cathode, and the improvement effect is directly related to the addition amount and particle size of copper powders. In addition, it is also revealed that the chemical reaction can occur between copper and intermediates MgS8 at the initial stage of discharge …

Optimizing the charge and ion transport of Nb2O5 composite is great significance for developing high-performance fast charge lithium-ion batteries. We designed Nb2O5 with oxygen vacancies through a simple and cost-effective hydrothermal and high-temperature calcination treatments. Oxygen vacancies can not only improve the electronic conductivity of the composite, but also effectively provide more active sites and reduce the ion transport barrier, which improved electrochemical reaction kinetics of the Nb2O5 composite. Consequently, the synthesized Nb2O5-x microflowers delivered a specific capacity of 191.2 mA h g−1 at 1C (a retention of 94% over 200 cycles) and outstanding rate capability (103.3 mA h g−1 at 50C) for lithium storage. Significantly, this work may also broaden the pathways for designing other electrode materials with oxygen vacancies for battery systems.

High-capacity Li-rich layered oxides (LLOs) hold giant promise as cathodes for Li-ion batteries but still suffer from cycling instability and voltage decay. The oxygen redox reaction and phase transformation to spinel are major incentives for performance deterioration. Hence, we propose a La-doping strategy to stabilize surface oxygen and reduce spinel phase components. The special La–O bond could exhibit not only an electrovalent characteristic bond but also a relative covalent property, which enhances the stability of lattice oxygen and the reversibility of oxygen redox. The spinel phase composition of surface area could be reduced through La doping, which suppresses capacity fade and voltage decay. Accordingly, the La-doping LLOs with Li and O vacancy defects forming at the surface area exhibit excellent reversible capacity (225 mA h/g at 1 C and 145 mA h/g at 5 C) and rate performance (80.68 and 81.76 …

LiNi0.5Mn1.5O4 is a promising cathode material with high-voltage and three-dimensional lithium-ion transport channels. Rapid capacity degradation due to HF corrosion has been a great challenge hindering the application of high-voltage cathode materials. Herein, a double protection strategy for high-performance LiNi0.5Mn1.5O4 cathodes has been designed using Li6.4La3Zr1.4Ta0.6O12 (LLZTO) with both high ionic conductivity and high surface basicity as the modifier of the poly(vinylidene fluoride) (PVDF) binder and the HF scavenger. It has been demonstrated that the modified PVDF binder possesses a higher Li+ diffusion coefficient than incipient PVDF, resulting in better overall electrochemical properties. Meanwhile, the result of first-principles calculations revealed that the reaction between HF and LLZTO has higher chemical reactivity than that between HF and LiNi0.5Mn1.5O4. The scanning electron …

The emerging direction toward the ever-growing market of wearable electronics has contributed to the progress made in energy storage systems that are flexible while maintaining their electrochemical performance. Endowing lithium-ion batteries with high flexibility is currently considered to be one of the most essential choices in future. Here, we first propose the basic deformation mode according to the manifestation of flexibility and constructively reevaluate the concept of flexible lithium-ion batteries. Furthermore, the failure mechanism of flexible lithium-ion batteries is investigated with regard to their mechanical failure and electrochemical failure, and the related strategies of battery design and manufacturing are analyzed. More importantly, an in-depth analysis is conducted on the approaches to overcome mechanical failure through stress dispersion, stress absorption, prestress concentration, stress transfer, and …

Knowledge of structure-performance relationship is a fundamental issue in the field of material design and engineering. Functional-directed fine tune of the crystal structure has always been inspiring but rarely implemented in energy storage materials. Here we develop an approach to improve the performance of LiNi0.8Co0.1Mn0.1O2 (NCM811), a typical Ni-rich layered cathode material, through building monoclinic surfaces onto hexagonal primary grains, simply accomplished by oxidizing the flake-like primary precursors with KMnO4. In this way, the local octahedral ligand field has been engineered by inducing Jahn-Teller distortion of low spin Ni3+ state, resulting in a three-dimensional monoclinic functional network spreading over a secondary particle. Such an elaborate monoclinic architecture stabilizes the hexagonal structure of primary grains from phase transitions, and also offers an interconnected highway …

Single-atom catalysts (SACs) featuring maximized atom utilization are, in no doubt, playing an increasingly significant role in aprotic lithium-oxygen batteries (LOBs). However, rational design and construction of SACs active sites remain enormously challenging due to the superficial understanding of their structure-function relationship. In this contribution, we provide new insight into the link between the catalytic effects of catalysts and the detailed nucleation/delithiation mechanisms of Li2O2 during the oxygen reduction/evolution reaction (ORR/OER). Here, a CuN2C2 SACs electrocatalyst is tailored for LOBs by a confined self-initiated dispersing strategy. The exposed Cu-N2 moieties as the driving force centers can promote the formation of micron-sized flower-shaped lithium peroxide and further accelerate the decomposition kinetics of lithium peroxide via a one-electron transfer way in turn. Under the catalysis of …

Lithium dendrite can cause battery failure and safety risks, which is a major obstacle for the commercial application of lithium metal anodes. Herein, an artificial protective layer with interface defects is proposed to promote the interfacial electrochemical kinetics and achieve the ultra-long electrochemical plating/stripping stability. Taking titanium oxide (TiO2) as a research object, the interfacial oxygen-deficient TiO2 coating (H-TiO2) shows the faster lithium ion diffusion kinetics compared to the pristine TiO2 layer and fresh lithium metal anode, and this interfacial defect chemistry can facilitate homogenous lithium ion flux and regulate lithium metal dendrite-free electrodeposition. Specifically, the H-TiO2 protective layer endows lithium metal anodes ultra-long cycling stability up to 1990 h at 2.0 mA cm−2 with a low overpotential of 27.5 mV. Remarkably, the artificial H-TiO2 coating improves the cycling stability (97.5 mAh …

Satisfactory electrochemical stability of extrinsic-interfaces between electrodes and electrolyte is the prerequisite for the safe and durable applications of all-solid-state Lithium batteries (ALBs). Unfortunately, the oxidative decomposition of anions from Li-salt at the extrinsic-interfaces of cathode side leads to the electrochemical instability during charge process. Here, a novel composite polymer electrolyte (CPE) containing flyash-treated (FA) submicro/micron particles and poly(ethylene oxide) (PEO) matrix is reported. After the addition of FA filler, Li+ transference number increases from 0.21 to 0.37 and electrochemical stability window reaches 5.2 V. FA as filler can efficiently immobilize (trifluoromethanesulfonyl) imide (TFSI–) anions and mitigate their irreversible oxidative decomposition at the extrinsic-interface of cathode||CPE due to the internal binding interaction between TFSI– anions and FA particles. ALBs …

Inhibiting the shuttle effect and accelerating the reaction kinetics of soluble lithium polysulfides (LiPS) are crucial for constructing high-performance lithium–sulfur (Li–S) batteries. Herein, a novel iodine-doped MXene (I-MXene)-modified separator is proposed to optimize the electrochemical performance of Li–S batteries. The I-MXene composite exhibits a uniform two-dimensional layer structure and high electronic conductivity, which are beneficial for building high conductivity and a thin/uniform coating layer. Additionally, the I-MXene can effectively immobilize LiPS through Ti–S bonds and accelerate the reaction kinetics of LiPS conversion. When combined with the KB/S cathode, the cell using the I-MXene-modified separator displays a high initial discharge capacity of 1308 and 761 mAh g–1 after 100 cycles at 0.2 C, as well as high C-rate capability (655 mAh g–1/2 C). With a sulfur area loading above 5 mg cm–2 …

Single atom tailored metal nanoparticles represent a new type of catalysts. Herein, we demonstrate a single atom‐cavity coupling strategy to regulate performance of single atom tailored nano‐catalysts. Selective atomic layer deposition (ALD) was conducted to deposit Ru single atoms on the surface concavities of PtNi nanoparticles (Ru‐ca‐PtNi). Ru‐ca‐PtNi exhibits a record‐high activity for methanol oxidation reaction (MOR) with 2.01 A mg−1Pt. Also, Ru‐ca‐PtNi showcases a significant durability with only 16 % activity loss. Operando electrochemical Fourier transform infrared spectroscopy (FTIR) and theoretical calculations demonstrate Ru single atoms coupled to cavities accelerate the CO removal by regulating d‐band center position. Further, the high diffusion barrier of Ru single atoms in concavities accounts for excellent stability. The developed Ru‐ca‐PtNi via single atom‐cavity coupling opens an …

Owing to the thinness and large lateral size, 2D Si materials exhibit very promising prospects as the high‐performance anodes of lithium‐ion batteries (LIBs). However, the facile synthesis of ultrathin 2D Si nanosheets (Si‐NSs) and their efficient application still remain a great challenge. Herein, the fabrication of ultrathin Si‐NSs with the average thickness of <2 nm is demonstrated using a unique etching‐reduction protocol. After hybridizing with graphene, the as‐prepared Si‐NSs@rGO material delivers ultrahigh rate capability (2395.8 mAh g−1 at 0.05 A g−1 and 1727.3 mAh g−1 at 10 A g−1), long cycling lifespan (1000 cycles at 2 A g−1 with a capacity decay rate of 0.05% per cycle) and high average Coulombic efficiency (99.85% during 1000 cycles). The superior performance is attributed to the ultrathinness of Si‐NSs that greatly improves the diffusivity and reversibility of Li+ ions. This work provides a strategy for …

High areal capacity is critical towards the practical application of silicon anodes for high-energy lithium ion batteries. Herein, a free-standing silicon-graphene (3D-Si/G) anode with ultrahigh areal capacity is proposed by manipulating electrode structure using 3D-printing. For the 3D-Si/G electrodes with the circle-grid pattern, electrode thickness and printed filament spacing can be precisely constructed and adjusted by controlling a computer program. In this configuration, the tailored free space between and inside the filaments are enough to withstand volume fluctuation of silicon anodes, which significantly improves the structure stability and integrity of electrodes and endows the great accessibility to lithium ions transport in thick electrodes. Furthermore, the unique edge-coaxial and internal-disordered structure in printed filaments greatly enhances the electrode mechanical stability. Simultaneously, the graphene …

Developing advanced non-precious metal catalysts towards acidic oxygen reduction reaction (ORR) is critical for electrochemical energy conversion devices. Fe-N-C catalysts are demonstrated to be the most promising alternatives to platinum-based catalysts for ORR. Herein, Fe single atoms (SAs) coordinated by pyridinic nitrogen catalysts (denoted as Fe-pyridinic N-C) are synthesized through pyrolysis of ZIF-8 encapsulating ferrocene. Owing to the synergistic effects between Fe SAs and pyridinic N, Fe-pyridinic N-C exhibits remarkable ORR activity and outstanding stability in acid media, evidenced by golden kinetic current density of 9.71 mA cm−2 at 0.8 V, along with only 21 mV decrease in half-wave potential after 20,000 cycles. Theoretical calculations demonstrate that pyridine-type N possesses stronger binding energy with Fe SAs compared with pyrrole-type N, in other words, high pyridinic N content will …

Magnesium/sulfur batteries have emerged as one of the considerable choices for next-generation batteries. However, its low voltage platform caused by the passivation of magnesium anode limits its actual energy density. Herein, a magnesium-lithium alloy is screened out as a passivation-free anode, which hinders the passivation reaction on the anode through the substitution reaction between lithium in the alloy and the magnesium ions in the electrolyte. The alloy anode exhibits an improved interfacial reaction kinetics, and the impedance is reduced by 5 orders of magnitude compared to that of magnesium anode. With passivation-free Mg-Li alloy anode, the magnesium/sulfur battery achieves an enhanced discharge voltage platform of 1.5 V and an energy density of 1829 Wh kg−1. This study provides a novel design of passivation-free magnesium alloy anode for high-energy-density magnesium/sulfur batteries.

Despite the tremendous efforts in developing Si-based anode materials, the instable structure and electrode/electrolyte interphase caused by the severe volumetric expansion/contraction still remain quite challenging for their application in Li-ion batteries (LIBs). Here we firstly propose and synthesize a micron-sized layered sieve-like porous silicon (LSP-Si) anode material by a facile etching and magnesiothermic reduction strategy. This LSP-Si material possesses special layered porous structure with evenly distributed pores in the layers, forming the interconnected nanonetwork like a sieve. Concomitant with this hierarchal layered porous structure, the LSP-Si microparticle can effectively accommodate the severe volume expansion and mitigate the stress concentration due to the mutual extrusion upon lithiation, and thus stable solid electrolyte interphase (SEI) films can be well maintained. Meanwhile, a large …

With the development of flexible devices, it is necessary to design high-performance power supplies with superior flexibility, durability, safety, etc., to ensure that they can be deformed with the device while retaining their electrochemical functions. Herein, we have designed a flexible lithium-ion battery inspired by the DNA helix structure. The battery structure is mainly composed of multiple thick energy stacks for energy storage and some grooves for stress buffers, which realized the spiral deformation of batteries. According to the results, the batteries exhibit less than 3% capacity degradation even after more than 31000 times of in situ dynamic mechanical loadings. Moreover, the mechanism of the battery with spiral deformability is further revealed. It is anticipated that this bioinspired design strategy could create unique opportunities for the commercialization of flexible batteries and fill the current gap in realizing …

SO2 is considered as the most poisonous ambient contaminant to proton exchange membrane fuel cell (PEMFC) cathodes, leading to severe Pt deactivation and oxygen reduction reaction (ORR) performance loss. Great efforts have been devoted to studying the deactivation and regeneration of SO2-poisoned Pt/C catalysts, but far less to cases with coexisting NO. Herein, the deactivation and regeneration processes of Pt surfaces during ORR in the presence of both SO2 and NO (in different molar ratios) are investigated by means of in situ electrochemical infrared spectroscopy and density functional theory (DFT) calculations. Interestingly, NO presents a stronger affinity to Pt sites than SO2—if an appropriate NO : SO2 ratio is applied, SO2 adsorption can be completely inhibited. Besides, the competitive adsorption of NO can weaken the Pt–S bond and expel adsorbed SO2. Given that adsorbed NO is readily …

Although Li4Ti5O2 (LTO) exhibits excellent cycling stability and high safety, the poor electronic conductivity and slow ion diffusion kinetics largely limit its practical applications. Herein, LTO/reduced graphite oxide (rGO) composite anodes have been fabricated via a simple and controlled self-assembly method. LTO nanoparticles with diameters ranging from 20 to 100 nm are tightly anchored on the rGO to form a unique hierarchical structure. Compared with pure LTO material, the ultrathin rGO film and nanoparticles endow LTO higher electronic conductivity, shorten Li+ diffusion paths and provide more active sites for lithium storage. As a result, the synergistic effect of rGO and unique morphology play a dominant role in high specific discharge capcacity, excellent cycling life and high-capacity retention at high-rate discharging for the LTO/rGO composite electrode. Specifically, large specific discharge capacity of 129 …

Lithium (Li) metal has been proposed as the most promising anode for secondary lithium batteries with high energy density due to its considerable theoretical capacity (3860 mAh g−1) and lowest electrochemical potential (-3.04 V vs standard hydrogen electrode). However, the uncontrollable dendrite Li issues over repeated plating/stripping process results in huge volume change, low Coulombic efficiencies (CEs), and poor cycling performance. Here, a solid electrolyte interphase (SEI) layer mainly consisting of biphasic hybrid Li3Sb and LiF has been successfully in situ constructed on Li surface by spontaneous chemical reaction between Li and SbF3. The modified SEI can induce Li ions depositing on the linked-particle layer resulting from the relative low lithium diffusion coefficient of SEI layer component. The Li/Li symmetric cells with SbF3-modified Li (SF-Li) anodes show stable cycling over 400 h at 3.0 mA cm …

Soluble redox mediators (RMs), an alternative to conventional solid catalysts, have been considered an effective countermeasure to ameliorate sluggish kinetics in the cathode of a lithium–oxygen battery recently. Nevertheless, the high mobility of RMs leads to serious redox shuttling, which induces an undesired lithium‐metal degeneration and RM decomposition during trade‐off catalysis against the sustainable operation of batteries. Here, a novel carbon family of graphdiyne matrix is first proposed to decouple the charge‐carrying redox property of ferrocene and the shuttle effects. It is demonstrated that a ferrocene‐anchored graphdiyne framework can function as stationary RM, not only preserving the redox‐mediating capability of ferrocene, but also promoting the local orientated three‐dimensional (3D) growth of Li2O2. As a result, the RM‐assisted catalysis in lithium–oxygen battery remains of remarkable …

Establishing a stable electrode-electrolyte interface (SEI) is extremely critical to achieving a reversible silicon anode for lithium ion batteries. Herein, a conformal polyurea layer with hydrogen bonds and polar functional groups is firstly controllably constructed on the silicon electrode as an artificial SEI via molecular layer deposition. The optimized polyurea coating of ∼3 nm greatly promotes the electrochemical lithium storage performance of silicon anodes, including highly reversible cycling stability (1010 mA h g−1 after 1000 cycles) and rate capability (1820 mA h g−1 at 2 A g−1, 1420 mA h g−1 at 5 A g−1). Analyses show that this polyurea layer can greatly promote lithium ions diffusion kinetic in the silicon electrodes and induce a stable, thin, and LiF-rich SEI with good mechanical stability. Moreover, this polyurea coating shows a significant improvement for larger-size silicon particles (even >150 nm) and superior …

Rechargeable lithium metal batteries (LMBs) have been regarded as one of the most promising next-generation energy-storage systems due to their high theoretical energy density. However, the practical application of LMBs is greatly impeded by poor high-voltage tolerance and safety concerns originated from flammable organic carbonate-based liquid electrolytes. Herein, a novel dual-salt gel polymer electrolyte (DS-GPE) is prepared via in situ polymerization of vinyl ethylene carbonate (VEC) and pentaerythritol tetra acrylate (PETEA) monomers in a poly (vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP) porous structure. The newly developed DS-GPE shows high ionic conductivity (6.9 mS cm− 1) at room temperature, adequate Li+ transference number (t Li+= 0.512), outstanding oxidative resistance (5.3 V vs. Li/Li+) and favorable interfacial compatibility. Stable interfacial layers are rich in B-, F …

Uniform lithium (Li) deposition and stable interface between anode and electrolyte are crucial factors for realizing the practical application of Li metal anode. Herein, a homogeneous lithium fluoride (LiF) protective layer with many nano slits is constructed on the Li anode by a facile vacuum evaporation method. It can uniformize the Li ion flux at surface of anode via its homogeneity and suppress the violent side reaction between Li and electrolyte via its good compactness. The existence of nano-slits allows the penetration of electrolyte and thus providing sufficient lithium ions transmission channels. Therefore, such a homogeneous LiF layer effectively inhibits the growth of Li dendrites and alleviates the consumption of active Li metal, significantly improving the stability of Li anode during long-term cycles. With the LiF-protected Li anode, the full cell with LiFePO4 cathode delivers 2.5 times longer lifespan and slower …

Mitigating the mechanical degradation and enhancing the ionic/electronic conductivity are critical but challengeable issues toward improving electrochemical performance of conversion‐type anodes in rechargeable batteries. Herein, these challenges are addressed by constructing interconnected 3D hierarchically porous structure synergistic with Nb single atom modulation within a Co3O4 nanocage (3DH‐Co3O4@Nb). Such a hierarchical‐structure nanocage affords several fantastic merits such as rapid ion migration and enough inner space for alleviating volume variation induced by intragrain stress and optimized stability of the solid‐electrolyte interface. Particularly, experimental studies in combination with theoretical analysis verify that the introduction of Nb into the Co3O4 lattice not only improves the electron conductivity, but also accelerates the surface/near‐surface reactions defined as pesudocapacitance …

Facilely upgrading 5-Hydroxymethylfurfural (HMF) via controllable oxidation of aldehyde and hydroxymethyl groups has attracted increasing attention since one of the products, 2,5-Furandicarboxylic acid (FDCA), is of great industrial value. Herein, the surface reconstruction of NiFeP and underlying dynamic Ni(OH)2-NiOOH transformation are characterized under electro-anodic HMF oxidation reaction (HMFOR). The Ni(OH)2-NiOOH/NiFeP heterojunction presents extraordinary HMFOR performance and produces FDCA with a yield over 99% and a Faradaic efficiency over 94%. The reconstructed NiOOH is suggested to chemically (not electrochemically) oxidize HMF while itself is reduced back to Ni(OH)2; The applied anodic potential then drives the oxidation of Ni(OH)2 to NiOOH, to circlize the HMF oxidation process. Meanwhile, the deeper oxidation of NiOOH to NiO(OH)2 or beyond can drive the oxygen …

Developing “ideal” binders to achieve ultrahigh area-capacity stable silicon (Si) anodes remains a significant challenge. Herein, a self-healing binder with a multilevel buffered structure is designed to alleviate the structural damage and performance degradation caused by extreme volume deformation of Si. In this multilevel configuration, employing the coexistence strategy of dynamic supramolecular interactions and rigid covalent bonds, the dopamine-grafted poly(acrylic acid) (PAA-DA) possesses abundant hydrogen bonds and strong viscoelasticity, which facilitates the dynamic reconstruction of the entire network. Moreover, the hydroxyl groups on the polyethylene glycol (PVA) form a strong covalent bond network with the carboxyl groups in PAA-DA under thermal polymerization conditions to ensure the integrity of the electrode structure. At 4 A g–1, the resulting Si electrode retains 1974.1 mAh g–1 after 500 …

Monoclinic Li3V2(PO4)3 is a promising cathode material with complex charge–discharge behavior. Previous structural investigation of this compound mainly focuses on local environments; while the reaction kinetics and the driving force of irreversibility of this material remain unclear. To fully understand the above issues, both the equilibrium and the non-equilibrium reaction routes have been systematically investigated in this study. Multiple characterization techniques including X-ray diffraction, variable temperature (spinning rate) and ex/in situ 7Li, 31P solid state NMR have been employed to provide comprehensive insights into kinetics, dynamics, framework structure evolution and charge ordering, which is essential to better design and application of lithium transition metal phosphate cathodes. Our results suggest that the kinetics process between the non-equilibrium and the quasi-equilibrium delithiation …

Proton exchange membrane (PEM) fuel cells using Pt-based materials as electrocatalysts have achieved a decent performance, represented by the launched Toyota Mirai vehicle. The ideal PEM fuel cells consume stored pure hydrogen and air. However, SO2, as a primary air contaminant, may be fed along with air at the cathode, leading to Pt site deactivation. Therefore, it is important to improve the SO2 tolerance of catalysts for the stability of the oxygen reduction reaction (ORR). In this work, we develop the Pt/C-TiO2 catalyst against SO2 poisoning during ORR. Impressively, the hybrid Pt/C-TiO2 catalyst with 20 mass % TiO2 shows the best ORR and anti-toxic performance: the kinetic current density of ORR is 20.5% higher and the degradation rate after poisoning is 50% lower than Pt/C. The interaction between Pt and TiO2 as well as the abundant hydroxyl groups on the surface of TiO2 are both revealed to account for the accelerated removal of poisonous SO2 on Pt surfaces.

The complicated interfacial problems of poly(ethylene oxide) (PEO)‐based solid polymer electrolytes (SPEs) at high voltages severely hinder its practical applications for high‐energy‐density all‐solid‐state lithium batteries (ASSLBs). Herein, the failure mechanisms of ASSLBs with LiNi0.6Co0.2Mn0.2O2 (NCM)‐PEO are studied. It is found that the ASSLBs after charge generates a sharp drop of 0.62 V at the cut‐off voltage of 4.30 V, and induce a high interfacial resistance due to forming an uneven thick cathode electrolyte interface on the NCM surface, as well as cause the destruction of NCM surface structure during storage, leading to serious performance degradation. Constructing the interfacial nanolayer with aromatic polyamide (APA) on the surface of NCM active particles (NCM@APA) can mitigate interfacial side reactions between NCM and SPE. Robust interfacial nanolayers not only effectively protect the …

Emerging directions in the growing wearable electronics market have spurred the development of flexible energy storage systems that require deformability while maintaining electrochemical performance. However, the traditional fabrication approaches of lithium‐ion batteries (LIBs) are challenging to withstand long‐cycle bending alternating loads due to the stress concentration caused by the nonuniformity of the actual deformation. Herein, inspired by kirigami, a segmented deformation design of full‐cell scale thin‐type flexible lithium‐ion batteries (FLIBs) with large‐scale manufacturing characteristics via the current collector's mechanical blanking process is reported. This strategy allows the battery's elliptical deformation of the actual state to be transformed into the circular strain of the ideal configuration, thereby dispersing the stress concentration on the top of the battery. According to the results, the designed …

The atomically dispersed dual metal atom catalysts exhibit significant promise for the electrochemical energy conversion technologies. Herein, the hetero-nuclear precious-non-precious (Au-Co) dual atoms have been synthesized and subsequently applied for the acidic oxygen reduction reaction (ORR). The (Au-Co) dual atoms exhibit an outstanding activity with half-wave potential (E1/2) of 0.82 V in 0.1 M HClO4. Additionally, the proton exchange membrane fuel cell (PEMFC) analysis reveals a peak power density of 360 mW cm−2 under H2/air condition. Co-N2C2 with axial Au atom moieties act as the active sites of the (Au-Co) dual atoms towards ORR. Further, *OH adsorbed on the Co atom induces a coordinated change in the adjacent Au atom symmetry, which leads the anti-bond spin orbitals to a low energy level, thus, further improving ORR performance. The development of (Au-Co) dual atoms via the …

Silicon anodes have attracted enormous attention with the merits of outstanding theoretical capacity for high-energy-density lithium-ion batteries. However, the drastic volume variation will destroy the structural integrity of the electrode system during the alloying/dealloying process. Herein, based on the supramolecular self-assembly, a multifunctional dynamic cross-linking strategy with self-healing chemistry and enhanced ionic conductivity for silicon electrode network structure is rationally designed by amino-functionalized silicon (Si-NH2) and dopamine-modified poly(acrylic acid) (PAA-DA). Dynamic reversible hydrogen bonds and ionic bonds are formed by random cross-linking of the primitives carried by the material, which endow the electrode with rapid self-healing ability and strong adhesion, and provide a continuous internal pathway for the electrode system. Moreover, the presence of polar groups can …

For micron-sized nickel-based hydroxides sheets, the reaction and migration of anions/water molecules in the inner region tends to lag behind those along the edge, which can cause structure mismatch and capacity degradation during cycles. Nanosizing and structure design is a feasible solution to shorten the ion/electron path and improve the reaction homogeneity. Herein, this study reports a novel three-stage strategy (self-assembly of NiMn-LDH/ppy-C — reduction to NiMn/ppy-C — in situ phase transformation into NiMn/NiMn-LDH/ppy-C) to reduce the sheet size of NiMn-LDH to nanometer. Triggered by electrochemical activation, NiMn-LDH nanosheets can hereby easily and orderly grow on the exposed active (1 1 1) crystal plane of Ni to establish NiMn-LDH/NiMn heterostructure around ppy-C. Importantly, nanosizing and hierarchical structure play a synergistic role to maintain structural integrity and to …

Rechargeable solid-state lithium metal battery (SSLMB) with high safety and energy density is regarded as one of the most promising candidates for next-generation energy-storage systems. However, the long-term interfacial stability between lithium metal anode and solid-state electrolyte is still a great challenge. Herein we propose an interfacial “molecular bridge” strategy to improve the interfacial adhesion between lithium metal anode and solid-state electrolyte by chemical bonding. As consequence, the lithium metal anode shows high interfacial wettability with solid-state electrolyte film, and Li/Li symmetrical cells display outstanding cycling stability with reduced polarization voltage, stable interfacial resistance, and dendrite-free lithium surface. In addition, high voltage LiCoO2 (LCO)/Li full cells show enhanced cycling stability and superior rate capability. Moreover, the LCO/Li pouch cell exhibits excellent …

Improving the ion/electron transport of TiNb2O7 composite is of great significance for achieving fast-charging lithium-ion batteries. Herein, we firstly report a rare-earth element engineering to tailor the bandgap and crystallographic structure for the dual function of electronic and ionic conductivity. Tb-doped TiNb2O7 (denoted as Tbx-TNO, x=0, 0.005, 0.010, 0.015) are successfully fabricated through a one-step solid-state reaction strategy. The Rietveld refinement technology of X-ray diffraction (XRD) demonstrates an effective substitution of Tb in the central sites of Nb-O octahedral. Significantly, in-situ XRD and ex-situ TEM techniques reveal the positive influence of Tb doping on the underlying ion transport behavior, which is verified by the increased unit cell volume, decreased mechanic effects, and promoted Li+-diffusion kinetics. DFT calculations demonstrate a narrow down of bandgap (from insulators to …

Transition metal cation ordering is essential for controlling the electrochemical performance of cubic spinel LiNi0.5Mn1.5O4 (LNMO), which is conventionally adjusted by optimizing the high temperature sintering and annealing procedures. In this present work, multiple characterization techniques, including 6,7Li NMR, XRD and HRTEM, have been combined to trace the phase transformation and morphology evolution during synthesis. It has been illustrated that simultaneous formation of LiMn2O4 (LMO) and LiNiO2 (LNO) binary oxides and their conversion into highly reactive LixNi3+yMn3.5+zO ternary intermediate is a thermal dynamically difficult but crucial step in the synthesis of LNMO ternary oxide. A new strategy of modifying the intermediates formation pathway from binary mode to ternary mode using thermal regulating agent has been adopted. LNMO synthesized with thermal regulating agent exhibits …

The Mg-metal batteries (MMBs) as a forceful competitor for Li-metal batteries (LMBs) have the advantages of high-safety and high-volume energy density. Whereas, the MMBs still confronts two vital issues to be addressed, including the incompatibility of conventional TFSI-based electrolytes with the Mg electrode and the poor reversibility of the cathode. In this work, to satisfyingly settle the incompatibility, an artificial interphase was first pre-constructed by high-temperature displacement reaction of CuCl2 and Mg metal, responsible for the faster charge-transfer rate and the lower Mg plating/stripping overpotential (∼0.2 V) in Mg symmetric cells. Regarding the Mg-Mo6S8 full cells, to enhance the reversibility and rate performance, Mg/Li hybrid batteries were designed. Consequently, the Mg-Mo6S8 battery can achieve excellent cycle stability and deliver a desirable capacity. Even as the current density increases to 1C …

The urgent market demand of energy storage and conversion has promoted the extensive investigations of coordination polymers. As a kind of simple cyano-bridged coordination polymers, Prussian blue (PB) and Prussian blue analogues (PBAs) have been considered as the promising cathode materials in sodium-ion batteries (SIBs) because of their 3D open framework, adjustable structure and chemical composition. Currently, the fundamental research and commercial exploration of PB and PBAs in nonaqueous SIBs are making robust progress. This review summarizes the recent advance and systematical cognition of PB and PBAs, mainly discussing the chemical composition and structure, material synthesis, modification strategy and sodium storage mechanism in nonaqueous SIBs. The structure-properties relationship of PB and PBAs is deeply revealed from the respects of bulk phase and interfacial stability …

Solid‐state electrolytes (SSEs) are attracting growing interest for next‐generation Li‐metal batteries with theoretically high energy density, but they currently suffer from safety concerns caused by dendrite growth, hindering their commercial applications. Interfaces between SSEs and solid lithium are argued to be crucial, affecting dendrite growth and determining solid‐state batteries (SSBs) performance. The buried and localized nature of the interface poses a huge challenge for direct characterization under working conditions. Recent review articles have been devoted to evaluating the conductivity and chemical stability of SSEs. Recognizing this, in this Review, the focus is on understanding lithium dendrite beyond conventional factors and offering a perspective on various surface/interface and microstructural phenomena that require close attention by both experimentalists and theoreticians. The complicated ion …

Solid-state electrolytes with high room temperature ionic conductivity, broad electrochemical window, and favorable thermal stability are crucial for the practical application of all-solid-state lithium-metal batteries. Here, a novel succinonitrile (SN)-based composite solid-state electrolyte (SN-CSSE) is fabricated directly inside the glass-fiber (GF) membrane via in-situ thermal-crosslinking ethoxylate trimethylolpropane triacrylate (ETPTA) monomer, coupled with the liquid SN-based electrolyte. The ionic conductivity, oxidation potential and lithium-ion transference number (TLi+) of SN-CSSE are 0.78 mS/cm, 5.20 V (vs. Li/Li+) and 0.68 at ambient temperature, respectively. The coin full cells equipped with high-voltage LiCoO2 (LCO) and modified Li metal anode deliver excellent interfacial stability, cycling reversibility, and rate capability. Moreover, the LCO/SN-CSSE/Li pouch cell exhibits more superior thermal stability …

Batteries can undergo overdischarge in actual applications without triggering safety issues. The interesting one is whether the battery that is overdischarged can have a second life in the following normal charge and discharge process. Herein, the effects of overdischarge are investigated using the LiCoO2/mesocarbon microbeads (MCMB) batteries with different depth of discharge (DOD) (102% DOD, 105% DOD, and 115% DOD) for ten times; the performance and aging mechanisms of the overdischarged battery in the following normal cycling are studied mainly through the electrochemical methods, scanning electron microscopy (SEM), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). For the batteries subjected to multiple shallow overdischarge (e.g., 102% DOD and 105% DOD), the aging mechanism remains unchanged, and the battery can be …

As one of the most promising next generation energy storage systems, lithium sulfur (Li-S) batteries with high specific energy density have received extensive attention due to the advantages of resource abundance, low toxicity and super high specific energy density (>2500 Wh kg−1). However, the unfavorable shuttle effect caused by dissolved polysulfides during charging/discharging processes results in low Coulombic efficiency (CE), poor interfacial stability, uncontrolled lithium dendrite growth and rapid capacity degradation, hindering the practical application of Li-S batteries. Herein, a highly stable armor-like artificial solid electrolyte interphase (SEI) layer for Li metal anode was formed based on the spontaneous interaction between Li metal and 4-chlorophenylboronic acid (CPB). First, this artificial SEI layer can avoid the direct contact between Li anode and electrolyte, therefore eliminating the corrosion …

Single-atom catalysts are becoming increasingly significant to numerous energy conversion reactions. However, their rational design and construction remain quite challenging due to the poorly understood structure–function relationship. Here we demonstrate the dynamic behavior of CuN2C2 site during operando oxygen reduction reaction, revealing a substrate-strain tuned geometry distortion of active sites and its correlation with the activity. Our best CuN2C2 site, on carbon nanotube with 8 nm diameter, delivers a sixfold activity promotion relative to graphene. Density functional theory and X-ray absorption spectroscopy reveal that reasonable substrate strain allows the optimized distortion, where Cu bonds strongly with the oxygen species while maintaining intimate coordination with C/N atoms. The optimized distortion facilitates the electron transfer from Cu to the adsorbed O, greatly boosting the oxygen …

SiOx/C composites with a void‐reserving structure are promising anodes for lithium‐ion batteries. However, the facile and controllable synthesis of uniformly dispersed SiOx and carbon components, simultaneously incorporating ample voids, still remains a great challenge. Herein, a molecular polymerization strategy is devised to construct SiOx/C hollow particles for lithium‐ion batteries. 3‐aminopropyltriethoxysilane and dialdehyde molecules are judiciously engineered as silicon and carbon precursors to produce the polymer hollow spheres (PHSs) through a one‐step aldimine condensation without any template and additive. A range of PHSs is obtained using terephthalaldehyde, glutaraldehyde, and glyoxal as the crosslinkers, demonstrating the high tunability of the strategy. Importantly, in situ pyrolysis of the PHSs warrants the homogeneous incorporation of SiOx (<5 nm) in carbon hollow capsids at a …

The effects of storage on the aging mechanisms of the battery have attracted a lot of attention. In practice, the battery for electric vehicles (EVs) can undergo short periods of higher temperature storage. Therefore, the widely-used LiNi0.5Co0.2Mn0.3O2/graphite batteries are stored at different temperatures (25 °C, 60 °C, and 70 °C) for 15 days, and then cycled under normal ambient environment. The aging mechanisms are analyzed by electrochemical characterizations and post-mortem analysis. The aging rate and mechanisms of batteries stored at a lower temperature (e.g. 25 °C and 60 °C) almost remain unchanged. According to the results of quantitative analysis, although the aging of batteries stored at a higher temperature (e.g. 70 °C) is attributed to the increased polarization, the underlying reasons might be different. Increased polarization at higher temperature is primarily ascribed to cathode decay in …

Ambient contaminants, e.g., sulfur dioxide (SO2), lead to severe Pt deactivation and performance loss of practical proton exchange membrane (PEM) fuel cells, which need to be removed immediately. We herein find that only partially adsorbed SO2 can be oxidized and removed at up to 1.5 V, even for a longer period. By contrast, interestingly, dynamic potential scanning for several cycles (usually > 8) can gradually regenerate poisoned Pt/C. In situ infrared spectroscopy demonstrates that parallel-bonded SO2 is forbidden to be electro-oxidized at a high potential but can be converted to easily oxidized atop-bonded and bridge-bonded SO2 at a low potential. Due to the potential-dependent transformation, SO2 is gradually oxidized and removed under dynamic potential scanning instead of potentiostatic polarization. Based on this regeneration mechanism, we propose a square wave-based protocol to completely …

Non‐precious metal‐based catalysts for oxygen evolution reaction (OER) have been extensively studied, among which the transition metal X‐ides (including phosph‐ides, sulf‐ides, nitr‐ides, and carb‐ides) materials are emerging as promising candidates to replace the benchmark Ir/Ru‐based materials in alkaline media. However, it is controversial whether the metal Xides host the real active sites since these metal Xides are thermodynamically unstable under a harsh OER environment—it has been reported that the initial metal Xides can be electrochemically oxidized and transformed into corresponding oxides and (oxy)hydroxides. Therefore, the metal Xides are argued as “pre‐catalysts”; the electrochemically formed oxides and (oxy)hydroxides are believed as the real active moieties for OER. Herein, the recent advances in understanding the transformation behavior of metal Xides during OER are re‐looked …

Divalent metal batteries, particularly those based on magnesium (Mg), could offer lower cost and higher safety and energy density than lithium (Li) batteries. Demonstration of a prototype Mg-based battery almost two decades ago led to efforts to find suitable electrolytes and Mg2+-ion insertion compounds and to modify the metal anode . However, no Mg-based electrochemical device has been practical for energy storage up to now. Drawbacks include low working voltages and poor cycling performance that result from the lack of an electrolyte that avoids formation of a passivation interface layer on the Mg anode or that allows fast Mg2+ migration in high-voltage metal-oxide cathodes (, ). On page 172 of this issue, Hou et al. propose a versatile electrolyte design strategy for divalent metal batteries in which strong chelating agents interact with the cations. This approach greatly increased the reversibility of the …

Developing suitable electrolytes with high oxidation decomposition potential, low cost, and good compatibility with electrode materials has been a critical challenge in realizing practical magnesium batteries. The emerging magnesium aluminum chloride complex (MACC) electrolytes based on inorganic chloride salts exhibit high Coulombic efficiencies for magnesium batteries. This review summarizes recent studies of MACC electrolytes, focusing on the synthesis, characterization, and chemical environment of Mg species, electrolytic conditioning of electrolytes, and their application in typical magnesium batteries. The electrolyte evolution and influencing factor of electrolytic conditioning are discussed, and several kinds of conditioning‐free MACC electrolytes are further introduced. Finally, future trends and perspectives in this field are discussed.

Doping have been considered as a prominent strategy to stabilize crystal structure of battery materials during the insertion and removal of alkali ions. The instructive knowledge and experience acquired from doping strategies predominate in cathode materials, but doping principle in anodes remains unclear. Here, we demonstrate that trace element doping enables stable conversion-reaction and ensures structural integrity for potassium ion battery (PIB) anodes. With a synergistic combination of X-ray tomography, structural probes, and charge reconfiguration, we encode the physical origins and structural evolution of electro-chemo-mechanical degradation in PIB anodes. By the multiple ion transport pathways created by the orderly hierarchical pores from “surface to bulk” and the homogeneous charge distribution governed in doped nanodomains, the anisotropic expansion can be significantly relieved with trace …

Sulfurized polyacrylonitrile (S@pPAN), as a promising high-capacity cathode material, can completely solve the shuttling effect of lithium polysulfide and deliver reliable electrochemical performance in ester-based electrolyte. Until now, the inferior sulfur content, sluggish reaction kinetics and obscure reaction mechanism of the S@pPAN cathodes are still the critical hurdles for attaining their practical application. Herein, the iodine-doped sulfurized polyacrylonitrile (I-S@pPAN) prepared by a simple co-heating method exhibits good electrochemical performance in ester electrolyte. The electrochemical measurements and DFT calculation demonstrate that iodine-doping can effectively promote the electron and Li+ migration of S@pPAN. In-situ EIS spectra reveals the generated cathode electrolyte interface (CEI) layer, containing LiF and LiI, is beneficial to enhance the reaction kinetics. Ex-situ solid state NMR and XPS …

Commercialization of rechargeable lithium metal batteries has long been hindered by the safety concerns associated with the undesirable lithium dendrite issues. To inhibit the uncontrolled dendrite growth, homogeneous ion transport to achieve even lithium plating is a necessity for lithium anode, but remain challenging. Inspired by traditional LixMnO2 materials with a fast Li+ transport, here we constructed 3D ionic-electronic transport channels with in-situ electrochemically lithiated MnO2. Taking advantages of the inherently fast ion transport and 3D conductive network, homogeneous ionic flux and reduced local current density can be achieved with this scaffold, contributing to even nucleation and uniform distribution of lithium plating. The dendrite-free anode shows a stable Li stripping/plating process with a low overpotential, and the full cell coupling the composite anode with LiFePO4 cathode delivers excellent …

Rechargeable Mg-ion batteries typically suffer from either rapid passivation of the Mg anode or severe corrosion of the current collectors by halogens within the electrolyte, limiting their practical implementation. Here, we demonstrate the broadly applicable strategy of forming an artificial solid electrolyte interphase (a-SEI) layer on Mg to address these challenges. The a-SEI layer is formed by simply soaking Mg foil in a tetraethylene glycol dimethyl ether solution containing LiTFSI and AlCl3, with Fourier transform infrared and ultraviolet–visible spectroscopy measurements revealing spontaneous reaction with the Mg foil. The a-SEI is found to mitigate Mg passivation in Mg(TFSI)2/DME electrolytes with symmetric cells exhibiting overpotentials that are 2 V lower compared to when the a-SEI is not present. This approach is extended to Mg(ClO4)2/DME and Mg(TFSI)2/PC electrolytes to achieve reversible Mg plating and …

The lithium–sulfur (Li–S) battery with a high theoretical energy density (2560 Wh kg–1) is one of the most promising candidates in next-generation energy storage systems. However, its practical application is impeded by the shuttle effect of lithium polysulfides, huge volume expansion, and overgrowth dendrite of lithium. Herein, we propose an artificial conformal agar polymer coating on a lithium anode (marked as A-Li). The functional layer facilitating the formation of a compact interphase on the lithium anode can effectively accommodate expansive volume and restrain the growth of dendritic lithium. The Li/Li symmetric cell with A-Li delivers stable plating/stripping cycling over 300 h at a high current density of 3.0 mA cm–2 and a high fixed areal capacity of 3.0 mAh cm–2. The cycle life of Li–Cu cells with A-Li is twice longer than that of pristine cells, and the Li–S batteries equipped with A-Li anodes also deliver an …

Lithium–sulfur (Li–S) batteries are drawing huge attention as attractive chemical power sources. However, traditional ether-based solvents (DME/DOL) suffer from safety issues at high temperatures and serious parasitic reactions occur between the Li metal anodes and soluble lithium polysulfides (LiPSs). Herein, we propose a polysulfide-suppressed and flame-retardant electrolyte operated at high temperatures by introducing an inert diluent 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl (TTE) into the high-concentration electrolyte (HCE). Li dendrites are also efficiently suppressed by the formed LiF-rich protective layer. Furthermore, the shuttle effect is mitigated by the decreased solubility of LiPSs. At 60 °C, Li–S batteries using this nonflammable ether-based electrolyte exhibit a high capacity of 666 mAh g–1 over 100 cycles at a current rate of 0.2C, showing the greatly improved high-temperature performance …

Mn doping is deemed as a promising strategy to improve the electrochemical performance of the α-Ni(OH)2 battery-type supercapacitor electrode. However, the internal structure evolution, the pathways and the dynamics of the proton/intercalated anion migration, as well as the functioning mechanism of Mn dopant to stabilize the layered structure during cycles remain unclear. Here, we unveil that irreversible oxidization of Mn3+ at the initial CV cycles, which will remain as Mn4+ in the NiO2 slabs after the first oxidization to effectively suppress the phase transformation from α-Ni(OH)2/γ-NiOOH to β-Ni(OH)2/β-NiOOH and further maintain the structural integrity of electrode. With a synergistic combination of theoretical calculations and various structural probes including XRD and 2H MAS solid state NMR, we decode the structure evolution and dynamics in the initial CV (cyclic voltammetry) cycles, including the …

Due to the good safety and high energy density, rechargeable Mg-metal batteries (RMMBs) have been regarded as a potential competitor of Li-metal batteries (LMBs). However, the Mg(TFSI)2-based conventional electrolytes will cause large overpotential in reversible plating/stripping attributed to the high ion transport impedance of the electrolyte decomposition products. Here, an artificial interphase composed of amorphous (a-) MgCl2@polymer on the Mg-metal surface is prepared by in-situ chemical reaction of metallic Mg with H3PO4 and SiCl4 in sequence, and can effectively inhibit the electrolyte decomposition and facilitate Mg2+ transport, which plays the role of solid electrolyte interface (SEI) on Mg anode. The Mg-Mg symmetrical cell with modified Mg electrode exhibits lower overpotential (~0.25 V) and interfacial impedance than bare Mg electrode in 0.5 M Mg(TFSI)2/DME electrolyte. The voltage hysteresis …

Mn-doping engineering route has been demonstrated an effective way to enhance the electronic conductivity of α-Ni(OH)2 as a hybrid supercapacitor electrode material. However, the problem of limited cycling lifetime remains unsolved and the structural evolution of Mn-doping at the atomic level is still under debate. Herein, a novel life span improving strategy is proposed to modulate the electronic configuration and the layer stacking mode of Mn doped Ni(OH)2 (NiMn-LDH) in situ grown on nickel foam by controlling the Mn doping level (~6% atomic) and occupied site (3a site only). XRD, EXAFS and DFT calculations have been employed to confirm that the modified electronic configuration due to Mn doping induces local contraction of metal-O/metal bond length and increases curve degree within ab planes, which further introduces special stacking fault disorder between layers to stabilize the structure. Finally, the …

Though LiCoO2/mesocarbon microbead (MCMB) battery has wide application, its capacity loss mechanisms at different cycling stages are still not clear. Here, we report the electrochemical behaviors in MCMB anode at different stages and their impacts on the capacity degradation. The exfoliation of anode material from current collector tends to occur in single-side pasted region, which is one of the reasons for the quick capacity fading at early stage. After long-term cycles, MCMB anode has larger capacity loss than LiCoO2 cathode. The carbonates with poor Li+ conductivity are formed in the solid electrolyte interface (SEI) film at later stage. MCMB structure has no obvious variations. Lithium deposits appear on single-side pasted region firstly and then double-side pasted region. They are distributed more widely and become thicker with the cycling. The deposits contain metallic lithium while the battery at …

Lithium–sulfur (Li–S) batteries have attracted significant attention because of their high theoretical energy density and low cost. However, their poor cyclability caused by the shuttle effect in ether‐based electrolytes remains a great challenge for their practical application. Herein, a novel electrolyte is proposed by combining widely used carbonate solvents diethyl carbonate/fluoroethylene carbonate and inert diluent 1,1,2,2‐tetrafluoroethyl 2,2,3,3‐tetrafluoropropyl ether for Li–S batteries based on typical mesoporous carbon/sulfur (KB/S) materials. Differing from the conventional dissolution‐precipitation mechanism, the sulfur cathodes demonstrate a solid‐phase reaction route in the developed electrolyte, which is realized with the assistance of an in situ formed compact cathode electrolyte interface (CEI) film on the cathode caused by the nucleophilic reaction between lithium polysulfides (LiPSs) and carbonate …

High-capacity conversion-type anodes suffer from sluggish ion/electron migration and tremendous mechanical degradations, severely restricting the cyclic performance in LIBs. The mentioned disadvantages can be efficiently eliminated by the development of electrode materials with gradient structure, decreased ion diffusion pathway, and enough reserve space. Herein, a new type 3D-interconnected hollow structure assembled by porous Co3O4 nanoparticles (HG-Co3O4@void) is proposed and fabricated as lithium-ion storage. HG-Co3O4@void exhibits high reversible capacity, superior rate performance, and long-term cycle stability (619 mAh g–1 after 500 cycles at 5 A g–1). The superior performance is attributed to the synergistic effects between large void space and massive ion channels, both which offer robust structure integrity and ultrafast Li+ transport inside HG-Co3O4@void. Besides, the prominent …

Selective and efficient oxidation of a certain hydroxyl group in biomass-derived polyols is quite appealing but challenging. We herein propose a new photoelectrochemical strategy for enhancing the selectivity and kinetics of the middle hydroxyl oxidation in glycerol molecules using Au/C3N4 catalyst. The introduction of illumination and usage of C3N4 are first demonstrated to have a direct bearing on enhancing the selectivity of middle hydroxyl oxidation on Au through the electron transfer and accelerating the kinetics by accumulating photogenerated holes with moderate oxidizability. By this strategy, the selectivity of glycerol to dihydroxyacetone and turnover frequency are achieved as high as 53.7% and unprecedented 4,619 h−1. The synergy of electronic interaction, localized surface plasmon resonance effect, and photogenerated carriers dual injection is revealed to account for such high selectivity and kinetics of …