The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batte...The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).展开更多
In recent years,sodium-ion batteries(SIBs)have become one of the hot discussions and have gradually moved toward industrialization.However,there are still some shortcomings in their performance that have not been well...In recent years,sodium-ion batteries(SIBs)have become one of the hot discussions and have gradually moved toward industrialization.However,there are still some shortcomings in their performance that have not been well addressed,including phase transition,structural degradation,and voltage platform.High entropy materials have recently gained significant attention from researchers due to their effects on thermodynamics,dynamics,structure,and performance.Researchers have attempted to use these materials in sodium-ion batteries to overcome their problems,making it a modification method.This paper aims to discuss the research status of high-entropy cathode materials for sodium-ion batteries and summarize their effects on sodium-ion batteries from three perspectives:Layered oxide,polyanion,and Prussian blue.The infiuence on material structure,the inhibition of phase transition,and the improvement of ion diffusivity are described.Finally,the advantages and disadvantages of high-entropy cathode materials for sodium-ion batteries are summarized,and their future development has prospected.展开更多
As battery technology evolves and demand for efficient energy storage solutions,aqueous zinc ion batteries(AZIBs)have garnered significant attention due to their safety and environmental benefits.However,the stability...As battery technology evolves and demand for efficient energy storage solutions,aqueous zinc ion batteries(AZIBs)have garnered significant attention due to their safety and environmental benefits.However,the stability of cathode materials under high-voltage conditions remains a critical challenge in improving its energy density.This review systematically explores the failure mechanisms of high-voltage cathode materials in AZIBs,including hydrogen evolution reaction,phase transformation and dissolution phenomena.To address these challenges,we propose a range of advanced strategies aimed at improving the stability of cathode materials.These strategies include surface coating and doping techniques designed to fortify the surface properties and structure integrity of the cathode materials under high-voltage conditions.Additionally,we emphasize the importance of designing antioxidant electrolytes,with a focus on understanding and optimizing electrolyte decomposition mechanisms.The review also highlights the significance of modifying conductive agents and employing innovative separators to further enhance the stability of AZIBs.By integrating these cutting-edge approaches,this review anticipates substantial advancements in the stability of high-voltage cathode materials,paving the way for the broader application and development of AZIBs in energy storage.展开更多
A tunable oxidization and reduction strategy was proposed to directly regenerate spent LiFePO_(4)/C cathode materials by oxidizing excessive carbon powders with the addition of FePO_(4).Experimental results indicate t...A tunable oxidization and reduction strategy was proposed to directly regenerate spent LiFePO_(4)/C cathode materials by oxidizing excessive carbon powders with the addition of FePO_(4).Experimental results indicate that spent LiFePO_(4)/C cathode materials with good performance can be regenerated by roasting at 650℃ for 11 h with the addition ofLi_(2)CO_(3),FePO_(4),V_(2)O_(5),and glucose.V_(2)O_(5) is added to improve the cycle performance of regenerated cathode materials.Glucose is used to revitalize the carbon layers on the surface of spent LiFePO_(4)/C particles for improving their conductivity.The regenerated V-doped LiFePO_(4)/C shows an excellent electrochemical performance with the discharge specific capacity of 161.36 mA·h/g at 0.2C,under which the capacity retention is 97.85%after 100 cycles.展开更多
Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,th...Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.展开更多
Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stab...Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stability.However,the inherently poor electronic conductivity and sluggish sodium-ion diffusion kinetics of NVP material give rise to inferior rate performance and unsatisfactory energy density,which strictly confine its further application in SIBs.Thus,it is of significance to boost the sodium storage performance of NVP cathode material.Up to now,many methods have been developed to optimize the electrochemical performance of NVP cathode material.In this review,the latest advances in optimization strategies for improving the electrochemical performance of NVP cathode material are well summarized and discussed,including carbon coating or modification,foreign-ion doping or substitution and nanostructure and morphology design.The foreign-ion doping or substitution is highlighted,involving Na,V,and PO_(4)^(3−)sites,which include single-site doping,multiple-site doping,single-ion doping,multiple-ion doping and so on.Furthermore,the challenges and prospects of high-performance NVP cathode material are also put forward.It is believed that this review can provide a useful reference for designing and developing high-performance NVP cathode material toward the large-scale application in SIBs.展开更多
Rechargeable magnesium batteries(RMBs)are a cutting-edge energy storage solution,with several advantages over the state-of-art lithiumion batteries(LIBs).The use of magnesium(Mg)metal as an anode material provides a m...Rechargeable magnesium batteries(RMBs)are a cutting-edge energy storage solution,with several advantages over the state-of-art lithiumion batteries(LIBs).The use of magnesium(Mg)metal as an anode material provides a much higher gravimetric capacity compared to graphite,which is currently used as the anode material in LIBs.Despite the significant advances in electrolyte,the development of cathode material is limited to materials that operate at low average discharge voltage(<1.0 V vs.Mg/Mg^(2+)),and developing high voltage cathodes remains challenging.Only a few materials have been shown to intercalate Mg^(2+)ions reversibly at high voltage.This review focuses on the structural aspects of cathode material that can operate at high voltage,including the Mg^(2+)intercalation mechanism in relation to its electrochemical properties.The materials are categorized into transition metal oxides and polyanions and subcategorized by the intrinsic Mg^(2+)diffusion path.This review also provides insights into the future development of each material,aiming to stimulate and guide researchers working in this field towards further advancements in high voltage cathodes.展开更多
Sodium-ion batteries have emerged as promising alternatives to lithium-ion batteries due to their abundant raw material reserves,low cost,enhanced safety,and environmental sustainability.Na_(2)Fe_(2)OS_(2),featuring a...Sodium-ion batteries have emerged as promising alternatives to lithium-ion batteries due to their abundant raw material reserves,low cost,enhanced safety,and environmental sustainability.Na_(2)Fe_(2)OS_(2),featuring a layered anti-perovskite structure,has attracted significant interest for its high capacity and facile synthesis.In this study,density functional theory calculations were performed to systematically investigate the phase stability,ionic conductivity,and voltage characteristics of Na_(2)Fe_(2)OS_(2)as a model system for anti-perovskite layered cathode materials.The compound exhibits excellent phase stability,and its equilibrium potential was calculated for the series Na_(x)Fe_(2)OCh_(2)(0<±<2)(where Ch represents chalcogenides).Naion transport analysis using the climbing image nudged elastic band method reveals a relatively low migration barrier(~0.47eV)along a dingonal pathway,indicating efficient Na^(+)mobility.To expand the materials design space,we systematically explored the effects of substituting Fe with various transition metals and replacing S with Se in NaaTM_(2)OCh_(2)structures.Among the variants studied,Na_(2)Mn_(2)OS_(2) demonstrates the most favorable combination of high voltage(~2.51V),robust phase stability,and superior energy density(~427 W-h/kg).This comprehensive comparison of transition metal substitutions provides vnluable insights for the rational design and experimental development of next-generation anti-perovskite layered cathode materials for sodium-ion batteries.展开更多
Sluggish conversion reaction kinetics and spontaneous shuttle effect of lithium polysulfides(LiPSs)are deemed as the two big mountains that hinder the practical application of lithium-sulfur batteries(LSBs).Herein,dua...Sluggish conversion reaction kinetics and spontaneous shuttle effect of lithium polysulfides(LiPSs)are deemed as the two big mountains that hinder the practical application of lithium-sulfur batteries(LSBs).Herein,dual-defect engineering strategy is implemented by introducing boron-doping and phosphorusvacancy sites with MoP@NC composite as the precursor.Based on the experimental characterizations and theoretical calculations,B-MoP_(1-x)@NC-based electrode presents low oxidation potential,high lithium diffusivity,small Tafel slope and strong adsorption capability for polysulfides,which is beneficial to enhance the adsorption capability for LiPSs,reduce the lithium diffusion energy barriers and Gibbs free energy for the conversion reactions of LiPSs.As demonstrated,the corresponding Li-S/B-MoP1-x@NC batteries can remain high reversible capacity of 753 mAh/g at 0.5 C after 300 cycles,and keep a stable capacity of 520 mAh/g at 0.5 C after 100 cycles even at the high-loading content of 5.1mg/cm^(2).According to the results of in-situ UV–vis spectra,the satisfactory battery performance majorly originates from the existence of dual-defect characteristics in B-MoP1-x@NC catalyst,which effectively promotes the conversion reaction kinetics of LiPSs,and restrains the shuttle behavior of LiPSs.The key ideas of this work will enlighten the development of catalytic cathode materials for sulfur-based secondary batteries.展开更多
With large-scale commercial applications of lithium-ion batteries(LIBs),lots of spent LIBs will be produced and cause huge waste of resources and greatly increased environmental problems.Thus,recycling spent LIB mater...With large-scale commercial applications of lithium-ion batteries(LIBs),lots of spent LIBs will be produced and cause huge waste of resources and greatly increased environmental problems.Thus,recycling spent LIB materials is inevitable.Due to high added-value features,converting spent LIB cathode materials into catalysts exhibits broad application prospects.Inspired by this,we review the high-added-value reutilization of spent LIB materials toward catalysts of energy conversion.First,the failure mechanism of spent LIB cathode materials are discussed,and then the transformation and modification strategies are summarized and analyzed to improve the transformation efficiency of failed cathode materials and the catalytic performance of catalysts,respectively.Moreover,the electrochemical applications of failed cathode material derived catalysts are introduced,and the key problems and countermeasures are analyzed and proposed.Finally,the future development trend and prospect of high-added-value reutilization for spent LIB cathode materials toward catalysts are also given.This review will predictably advance the awareness of valorizing spent lithium-ion battery cathode materials for catalysis.展开更多
Ni-rich cathode materials have become the mainstream choice in the mileage electric vehicle sector due to their high specific capacity and safety factor.However,the volume changes occurring during charging and dischar...Ni-rich cathode materials have become the mainstream choice in the mileage electric vehicle sector due to their high specific capacity and safety factor.However,the volume changes occurring during charging and discharging lead to microcracking and surface remodeling,posing challenges to achieving such as high specific capacity and long cycle stability.This paper reviews existing modification strategies for Ni-rich layered oxide cathode materials.Unlike previous reviews and related papers,we comprehensively discuss a variety of modification strategies and deeply discuss the synergistic modification effect of surface coating and bulk doping,which is how to improve the cycling stability of the Ni-rich cathode.In addition,based on recent research advances,the prospects and challenges of modifying Ni-rich layered cathodes for cycle stability upgrading of the lithium-ion battery,as well as the potential application prospects in the field of power automobiles,are comprehensively analyzed.展开更多
Magnesium-ion batteries hold promise as future energy storage solutions,yet current Mg cathodes are challenged by low voltage and specific capacity.Herein,we present an AI-driven workflow for discovering high-performa...Magnesium-ion batteries hold promise as future energy storage solutions,yet current Mg cathodes are challenged by low voltage and specific capacity.Herein,we present an AI-driven workflow for discovering high-performance Mg cathode materials.Utilizing the common characteristics of various ionic intercalation-type electrodes,we design and train a Crystal Graph Convolutional Neural Network model that can accurately predict electrode voltages for various ions with mean absolute errors(MAE)between0.25 and 0.33 V.By deploying the trained model to stable Mg compounds from Materials Project and GNoME AI dataset,we identify 160 high voltage structures out of 15,308 candidates with voltages above3.0 V and volumetric capacity over 800 mA h/cm^(3).We further train a precise NequIP model to facilitate accurate and rapid simulations of Mg ionic conductivity.From the 160 high voltage structures,the machine learning molecular dynamics simulations have selected 23 cathode materials with both high energy density and high ionic conductivity.This Al-driven workflow dramatically boosts the efficiency and precision of material discovery for multivalent ion batteries,paving the way for advanced Mg battery development.展开更多
A collaborative optimization method for the sintering schedule of ternary cathode materials was proposed under microscopic coupling constraints.An oxygen vacancy concentration prediction model based on microscopic the...A collaborative optimization method for the sintering schedule of ternary cathode materials was proposed under microscopic coupling constraints.An oxygen vacancy concentration prediction model based on microscopic thermodynamics and a growth kinetics model based on neural networks were established.Then,optimization formulations were constructed in three stages to obtain an optimal sintering schedule that minimized energy consumption for different requirements.Simulations demonstrate that the models accurately predict the oxygen vacancy concentrations and grain size,with root mean square errors of approximately 5%and 3%,respectively.Furthermore,the optimized sintering schedule not only meets the required quality standards but also reduces sintering time by 12.31%and keeping temperature by 11.96%.This research provides new insights and methods for the preparation of ternary cathode materials.展开更多
Although lithium-ion batteries(LIBs)currently dominate a wide spectrum of energy storage applications,they face challenges such as fast cycle life decay and poor stability that hinder their further application.To addr...Although lithium-ion batteries(LIBs)currently dominate a wide spectrum of energy storage applications,they face challenges such as fast cycle life decay and poor stability that hinder their further application.To address these limitations,element doping has emerged as a prevalent strategy to enhance the discharge capacity and extend the durability of Li-Ni-Co-Mn(LNCM)ternary compounds.This study utilized a machine learning-driven feature screening method to effectively pinpoint four key features crucially impacting the initial discharge capacity(IC)of Li-Ni-Co-Mn(LNCM)ternary cathode materials.These features were also proved highly predictive for the 50^(th)cycle discharge capacity(EC).Additionally,the application of SHAP value analysis yielded an in-depth understanding of the interplay between these features and discharge performance.This insight offers valuable direction for future advancements in the development of LNCM cathode materials,effectively promoting this field toward greater efficiency and sustainability.展开更多
With the rapid development of new energy and the high proportion of new energy connected to the grid,energy storage has become the leading technology driving significant adjustments in the global energy landscape.Elec...With the rapid development of new energy and the high proportion of new energy connected to the grid,energy storage has become the leading technology driving significant adjustments in the global energy landscape.Electrochemical energy storage,as the most popular and promising energy storage method,has received extensive attention.Currently,the most widely used energy storage method is metal-ion secondary batteries,whose performance mainly depends on the cathode material.Prussian blue analogues(PBAs)have a unique open framework structures that allow quick and reversible insertion/extraction of metal ions such as Na^(+),K^(+),Zn^(2+),Li^(+)etc.,thus attracting widespread attention.The advantages of simple synthesis process,abundant resources,and low cost also distinguish it from its counterparts.Unfortunately,the crystal water and structural defects in the PBAs lattice that is generated during the synthesis process,as well as the low Na content,significantly affect their electrochemical performance.This paper focuses on PBAs’synthesis methods,crystal structure,modification strategies,and their potential applications as cathode materials for various metal ion secondary batteries and looks forward to their future development direction.展开更多
Full-manganese(Mn)Li-rich materials have gained attention owing to the limited availability of cobalt-or nickel-based cathodes commonly used in batteries,which greatly restricts their potential for large-scale applica...Full-manganese(Mn)Li-rich materials have gained attention owing to the limited availability of cobalt-or nickel-based cathodes commonly used in batteries,which greatly restricts their potential for large-scale application.However,their practical implementation is hindered by the rapid voltage/capacity decay during cycling and the long-standing problem of redox kinetics due to their poor ionic conductivity based on the ordered honeycomb structure.In this study,the kinetic and thermodynamic properties of intralayer disordered and ordered Li-rich full-Mn-based cathode materials were compared,demonstrating that the disordered R3m Li_(0.6)[Li_(0.2)Mn_(0.8)]O_(2)(D-LMO)delivers a significant advantage of rate capability over the ordered C2/m Li_(0.6)[Li_(0.2)Mn_(0.8)]O_(2)(O-LMO).Meanwhile,the D-LMO keeps superior capacity retention of up to 99%after 50 cycles under 25 mAg^(-1).In comparsion,the capacity retention of the O-LMO drops to just 70%,and its average discharge voltage is 0.2 V lower than that of the D-LMO.Herein,we conducted systematic density functional theory(DFT)simulations,focusing on the electronic structure modulation governing the voltage platform between the ordered and disordered phases.The ab initio molecular dynamics(AIMD)results indicated that the energy of the intralayer disordered structure fluctuates around the equilibrium position without any abrupt drops,demonstrating excellent stability.This study enhances the understanding of intralayer disordered full-Mn Li-rich material and provides insights into the design of low-cost,high-performance cathode materials for Li-ion batteries.展开更多
Although manganese-based oxide is regarded as a promising cathode material for zincion hybrid supercapacitors(ZHSCs),its practical application is hindered by slow zinc ion diffusion and the instability of MnO_(2).To o...Although manganese-based oxide is regarded as a promising cathode material for zincion hybrid supercapacitors(ZHSCs),its practical application is hindered by slow zinc ion diffusion and the instability of MnO_(2).To overcome this obstacle,a δ-MnO_(2)/MXene heterostructure was created using a simple one-step process under gentle condition.The ZHSC was assembled using this heterostructure as the cathode,activated carbon(AC)as the anode and 2 mol·L−1 ZnSO_(4) as the electrolyte.The resultingδ-MnO_(2)/MXene//ZnSO4//AC ZHSC shows a maximum specific capacitance of 97.4 F·g^(−1) and an energy density of 32.27 Wh·kg^(−1) at the best cathode-to-anode mass ratio.Ex situ characterizations reveal the reversible energy storage mechanism combing Zn^(2+)insertion/extraction in the cathode,ion adsorption and desorption on the anode surface,and partial reversible formation and dissolution of Zn_(4)SO_(4)(OH)_(6)·5H_(2)O(ZHS)components on both electrodes.Adding of Mn^(2+)to the electrolyte reduced Mn dissolution,improving the ZHSC’s specific capacitance and energy density to 140.4 F·g^(−1) and 49.36 Wh·kg^(−1),respectively,while also enhancing its rate performance and cyclability.The improved electrochemical reaction kinetics was verified through various tests.The results suggest that the δ-MnO_(2)/MXene heterostructure has great potential as a high-performance cathode material for ZHSCs.展开更多
Li[NixCoyMn2]O2（0.6≤x≤0.8） cathode materials with a typical hexagonal α-NaFeO2 structure were prepared utilizing a co-precipitation method.It is found that the ratio of peak intensities of（003） to（104） observ...Li[NixCoyMn2]O2（0.6≤x≤0.8） cathode materials with a typical hexagonal α-NaFeO2 structure were prepared utilizing a co-precipitation method.It is found that the ratio of peak intensities of（003） to（104） observed from X-ray diffraction（XRD）increases with decreasing the Ni content or increasing the Co content.The scanning electron microscopy（SEM） images reveal that the small primary particles are agglomerated to form the secondary ones.As the Mn content increases,the primary and secondary particles become larger and the resulted particle size for the Li[Ni（0.6）Co（0.2）Mn（0.2）]O2 is uniformly distributed in the range of100-300 nm.Although the initial discharge capacity of the Li/Li[NixCoyMn2]O2 cells reduces with decreasing the Ni content,the cyclic performance and rate capability are improved with higher Mn or Co content.The Li[Ni（0.6）Co（0.2）Mn（0.2）]O2 can deliver excellent cyclability with a capacity retention of 97.1%after 50 cycles.展开更多
Li3V2（PO4）3 precursor was obtained with V2Os.nH2O , LiOH＇H2O, NH4H2PO4 and sucrose as starting materials by grinding-sol-gel method, and then the monoclinic-typed Li3Vz（PO4）3 cathode material was prepared by sint...Li3V2（PO4）3 precursor was obtained with V2Os.nH2O , LiOH＇H2O, NH4H2PO4 and sucrose as starting materials by grinding-sol-gel method, and then the monoclinic-typed Li3Vz（PO4）3 cathode material was prepared by sintering the amorphous Li3V2（PO4）3. The as-sintered samples were investigated by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, N2 adsorption-desorption and electrochemical measurement. It is found that Li3Vz（PO4）3 sintered at 700 ℃ possesses good wormhole-like mesoporous structure with the largest specific surface area of 188 cmZ/g, and the smallest pore size of 9.3 nm. Electrochemical test reveals that the initial discharge capacity of the 700 ℃ sintered sample is 155.9 mA.h/g at the rate of 0.2C, and the capacity retains 154 mA.h/g after 50 cycles, exhibiting a stable discharge capacity at room temperature.展开更多
In this paper,overcharge behaviors and thermal runaway(TR)features of large format lithium-ion(Liion)cells with different cathode materials(LiFePO4(LFP),Li[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_(2)(NCM111),Li[Ni_(0.6)Co_(0.2)Mn_...In this paper,overcharge behaviors and thermal runaway(TR)features of large format lithium-ion(Liion)cells with different cathode materials(LiFePO4(LFP),Li[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_(2)(NCM111),Li[Ni_(0.6)Co_(0.2)Mn_(0.2)]O_(2)(NCM622)and Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(NCM811))were investigated.The results showed that,under the same overcharge condition,the TR of LFP Li-ion cell occurred earlier compared with the NCM Li-ion cells,indicating its poor overcharge tolerance and high TR risk.However,when TR occurred,LFP Li-ion cell exhibited lower maximum temperature and mild TR response.All NCM Liion cells caught fire or exploded during TR,while the LFP Li-ion cell only released a large amount of smoke without fire.According to the overcharge behaviors and TR features,a safety assessment score system was proposed to evaluate the safety of the cells.In short,NCM Li-ion cells have better performance in energy density and overcharge tolerance(or low TR risk),while LFP Li-ion cell showed less severe response to overcharging(or less TR hazards).For NCM Li-ion cells,as the ratio of nickel in cathode material increases,the thermal stability of the cathode materials becomes poorer,and the TR hazards increase.Such a comparison study on large format Li-ion cells with different cathode materials can provide deeper insights into the overcharge behaviors and TR features,and provide guidance for engineers to reasonably choose battery materials in automotive applications.展开更多
基金supported by the Low-Cost Long-Life Batteries program,China(No.WL-24-08-01)the National Natural Science Foundation of China(No.22279007)。
文摘The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).
基金the National Natural Science Foundation of China Key Program(No.U22A20420)Changzhou Leading Innovative Talents Introduction and Cultivation Project(No.CQ20230109)for supporting our work。
文摘In recent years,sodium-ion batteries(SIBs)have become one of the hot discussions and have gradually moved toward industrialization.However,there are still some shortcomings in their performance that have not been well addressed,including phase transition,structural degradation,and voltage platform.High entropy materials have recently gained significant attention from researchers due to their effects on thermodynamics,dynamics,structure,and performance.Researchers have attempted to use these materials in sodium-ion batteries to overcome their problems,making it a modification method.This paper aims to discuss the research status of high-entropy cathode materials for sodium-ion batteries and summarize their effects on sodium-ion batteries from three perspectives:Layered oxide,polyanion,and Prussian blue.The infiuence on material structure,the inhibition of phase transition,and the improvement of ion diffusivity are described.Finally,the advantages and disadvantages of high-entropy cathode materials for sodium-ion batteries are summarized,and their future development has prospected.
基金supported by the Exchange Program of Highend Foreign Experts of Ministry of Science and Technology of People’s Republic of China(No.G2023041003L)the Natural Science Foundation of Shaanxi Provincial Department of Education(No.23JK0367)+1 种基金the Scientific Research Startup Program for Introduced Talents of Shaanxi University of Technology(Nos.SLGRCQD2208,SLGRCQD2306,SLGRCQD2133)Contaminated Soil Remediation and Resource Utilization Innovation Team at Shaanxi University of Technology。
文摘As battery technology evolves and demand for efficient energy storage solutions,aqueous zinc ion batteries(AZIBs)have garnered significant attention due to their safety and environmental benefits.However,the stability of cathode materials under high-voltage conditions remains a critical challenge in improving its energy density.This review systematically explores the failure mechanisms of high-voltage cathode materials in AZIBs,including hydrogen evolution reaction,phase transformation and dissolution phenomena.To address these challenges,we propose a range of advanced strategies aimed at improving the stability of cathode materials.These strategies include surface coating and doping techniques designed to fortify the surface properties and structure integrity of the cathode materials under high-voltage conditions.Additionally,we emphasize the importance of designing antioxidant electrolytes,with a focus on understanding and optimizing electrolyte decomposition mechanisms.The review also highlights the significance of modifying conductive agents and employing innovative separators to further enhance the stability of AZIBs.By integrating these cutting-edge approaches,this review anticipates substantial advancements in the stability of high-voltage cathode materials,paving the way for the broader application and development of AZIBs in energy storage.
基金National Natural Science Foundation of China(Nos.52174269,52374293)Science and Technology Innovation Program of Hunan Province,China(Nos.2024CK1009,2022RC1123)。
文摘A tunable oxidization and reduction strategy was proposed to directly regenerate spent LiFePO_(4)/C cathode materials by oxidizing excessive carbon powders with the addition of FePO_(4).Experimental results indicate that spent LiFePO_(4)/C cathode materials with good performance can be regenerated by roasting at 650℃ for 11 h with the addition ofLi_(2)CO_(3),FePO_(4),V_(2)O_(5),and glucose.V_(2)O_(5) is added to improve the cycle performance of regenerated cathode materials.Glucose is used to revitalize the carbon layers on the surface of spent LiFePO_(4)/C particles for improving their conductivity.The regenerated V-doped LiFePO_(4)/C shows an excellent electrochemical performance with the discharge specific capacity of 161.36 mA·h/g at 0.2C,under which the capacity retention is 97.85%after 100 cycles.
基金support of the National Natural Science Foundation of China(Grant No.22225801,22178217 and 22308216)supported by the Fundamental Research Funds for the Central Universities,conducted at Tongji University.
文摘Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.
基金partly supported by the National Natural Science Foundation of China(Grant No.52272225).
文摘Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stability.However,the inherently poor electronic conductivity and sluggish sodium-ion diffusion kinetics of NVP material give rise to inferior rate performance and unsatisfactory energy density,which strictly confine its further application in SIBs.Thus,it is of significance to boost the sodium storage performance of NVP cathode material.Up to now,many methods have been developed to optimize the electrochemical performance of NVP cathode material.In this review,the latest advances in optimization strategies for improving the electrochemical performance of NVP cathode material are well summarized and discussed,including carbon coating or modification,foreign-ion doping or substitution and nanostructure and morphology design.The foreign-ion doping or substitution is highlighted,involving Na,V,and PO_(4)^(3−)sites,which include single-site doping,multiple-site doping,single-ion doping,multiple-ion doping and so on.Furthermore,the challenges and prospects of high-performance NVP cathode material are also put forward.It is believed that this review can provide a useful reference for designing and developing high-performance NVP cathode material toward the large-scale application in SIBs.
基金supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(RS-2024-00446825)by the Technology Innovation Program(RS-2024-00418815)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘Rechargeable magnesium batteries(RMBs)are a cutting-edge energy storage solution,with several advantages over the state-of-art lithiumion batteries(LIBs).The use of magnesium(Mg)metal as an anode material provides a much higher gravimetric capacity compared to graphite,which is currently used as the anode material in LIBs.Despite the significant advances in electrolyte,the development of cathode material is limited to materials that operate at low average discharge voltage(<1.0 V vs.Mg/Mg^(2+)),and developing high voltage cathodes remains challenging.Only a few materials have been shown to intercalate Mg^(2+)ions reversibly at high voltage.This review focuses on the structural aspects of cathode material that can operate at high voltage,including the Mg^(2+)intercalation mechanism in relation to its electrochemical properties.The materials are categorized into transition metal oxides and polyanions and subcategorized by the intrinsic Mg^(2+)diffusion path.This review also provides insights into the future development of each material,aiming to stimulate and guide researchers working in this field towards further advancements in high voltage cathodes.
基金supported by the National Natural Science Foundation of China(Grant Nos.12404264 and 22209067)Shenzhen Basic Research Program(Natural Science Foundation)Key Project of Basic Research(Grant No.JCYJ20241202123916023)Shenzhen Science and Technology Program(Grant No.KQTD20200820113047086)。
文摘Sodium-ion batteries have emerged as promising alternatives to lithium-ion batteries due to their abundant raw material reserves,low cost,enhanced safety,and environmental sustainability.Na_(2)Fe_(2)OS_(2),featuring a layered anti-perovskite structure,has attracted significant interest for its high capacity and facile synthesis.In this study,density functional theory calculations were performed to systematically investigate the phase stability,ionic conductivity,and voltage characteristics of Na_(2)Fe_(2)OS_(2)as a model system for anti-perovskite layered cathode materials.The compound exhibits excellent phase stability,and its equilibrium potential was calculated for the series Na_(x)Fe_(2)OCh_(2)(0<±<2)(where Ch represents chalcogenides).Naion transport analysis using the climbing image nudged elastic band method reveals a relatively low migration barrier(~0.47eV)along a dingonal pathway,indicating efficient Na^(+)mobility.To expand the materials design space,we systematically explored the effects of substituting Fe with various transition metals and replacing S with Se in NaaTM_(2)OCh_(2)structures.Among the variants studied,Na_(2)Mn_(2)OS_(2) demonstrates the most favorable combination of high voltage(~2.51V),robust phase stability,and superior energy density(~427 W-h/kg).This comprehensive comparison of transition metal substitutions provides vnluable insights for the rational design and experimental development of next-generation anti-perovskite layered cathode materials for sodium-ion batteries.
基金financial support from National Natural Science Foundation of China(No.52101250)Hebei Provincial Natural Science Foundation(Nos.E2021208031 and B2021208069)+6 种基金S&T program of Hebei(Nos.215A4401D and 225A4404D)Research Fund of the Innovation Platform for Academicians of Hainan Province(No.YSPTZX202315)Collaborative Innovation Center of Marine Science and Technology of Hainan University(No.XTCX2022HYC14)partially supported by the Pico Election Microscopy Center of Hainan UniversityFundamental Research Funds for the Hebei University(No.2021YWF11)Science Research Project of Hebei Education Department(No.QN2024087)Xingtai City Natural Science Foundation(No.2023ZZ027)
文摘Sluggish conversion reaction kinetics and spontaneous shuttle effect of lithium polysulfides(LiPSs)are deemed as the two big mountains that hinder the practical application of lithium-sulfur batteries(LSBs).Herein,dual-defect engineering strategy is implemented by introducing boron-doping and phosphorusvacancy sites with MoP@NC composite as the precursor.Based on the experimental characterizations and theoretical calculations,B-MoP_(1-x)@NC-based electrode presents low oxidation potential,high lithium diffusivity,small Tafel slope and strong adsorption capability for polysulfides,which is beneficial to enhance the adsorption capability for LiPSs,reduce the lithium diffusion energy barriers and Gibbs free energy for the conversion reactions of LiPSs.As demonstrated,the corresponding Li-S/B-MoP1-x@NC batteries can remain high reversible capacity of 753 mAh/g at 0.5 C after 300 cycles,and keep a stable capacity of 520 mAh/g at 0.5 C after 100 cycles even at the high-loading content of 5.1mg/cm^(2).According to the results of in-situ UV–vis spectra,the satisfactory battery performance majorly originates from the existence of dual-defect characteristics in B-MoP1-x@NC catalyst,which effectively promotes the conversion reaction kinetics of LiPSs,and restrains the shuttle behavior of LiPSs.The key ideas of this work will enlighten the development of catalytic cathode materials for sulfur-based secondary batteries.
基金supported by the National Key Research and Development Program of China(No.2023YFB3809300).
文摘With large-scale commercial applications of lithium-ion batteries(LIBs),lots of spent LIBs will be produced and cause huge waste of resources and greatly increased environmental problems.Thus,recycling spent LIB materials is inevitable.Due to high added-value features,converting spent LIB cathode materials into catalysts exhibits broad application prospects.Inspired by this,we review the high-added-value reutilization of spent LIB materials toward catalysts of energy conversion.First,the failure mechanism of spent LIB cathode materials are discussed,and then the transformation and modification strategies are summarized and analyzed to improve the transformation efficiency of failed cathode materials and the catalytic performance of catalysts,respectively.Moreover,the electrochemical applications of failed cathode material derived catalysts are introduced,and the key problems and countermeasures are analyzed and proposed.Finally,the future development trend and prospect of high-added-value reutilization for spent LIB cathode materials toward catalysts are also given.This review will predictably advance the awareness of valorizing spent lithium-ion battery cathode materials for catalysis.
基金supported by the Science and Technology Research Project of Changchun City(24GXYSZZ01)the Natural Science Foundation of Jilin Province(NO.20220101036JC)。
文摘Ni-rich cathode materials have become the mainstream choice in the mileage electric vehicle sector due to their high specific capacity and safety factor.However,the volume changes occurring during charging and discharging lead to microcracking and surface remodeling,posing challenges to achieving such as high specific capacity and long cycle stability.This paper reviews existing modification strategies for Ni-rich layered oxide cathode materials.Unlike previous reviews and related papers,we comprehensively discuss a variety of modification strategies and deeply discuss the synergistic modification effect of surface coating and bulk doping,which is how to improve the cycling stability of the Ni-rich cathode.In addition,based on recent research advances,the prospects and challenges of modifying Ni-rich layered cathodes for cycle stability upgrading of the lithium-ion battery,as well as the potential application prospects in the field of power automobiles,are comprehensively analyzed.
基金supported by the National Key R&D Program of China(2022YFA1203400)the National Natural Science Foundation of China(W2441009)。
文摘Magnesium-ion batteries hold promise as future energy storage solutions,yet current Mg cathodes are challenged by low voltage and specific capacity.Herein,we present an AI-driven workflow for discovering high-performance Mg cathode materials.Utilizing the common characteristics of various ionic intercalation-type electrodes,we design and train a Crystal Graph Convolutional Neural Network model that can accurately predict electrode voltages for various ions with mean absolute errors(MAE)between0.25 and 0.33 V.By deploying the trained model to stable Mg compounds from Materials Project and GNoME AI dataset,we identify 160 high voltage structures out of 15,308 candidates with voltages above3.0 V and volumetric capacity over 800 mA h/cm^(3).We further train a precise NequIP model to facilitate accurate and rapid simulations of Mg ionic conductivity.From the 160 high voltage structures,the machine learning molecular dynamics simulations have selected 23 cathode materials with both high energy density and high ionic conductivity.This Al-driven workflow dramatically boosts the efficiency and precision of material discovery for multivalent ion batteries,paving the way for advanced Mg battery development.
基金supported by the National Natural Science Foundation of China(No.62033014)the Application Projects of Integrated Standardization and New Paradigm for Intelligent Manufacturing from the Ministry of Industry and Information Technology of China in 2016,and the Fundamental Research Funds for the Central Universities of Central South University,China(No.2021zzts0700).
文摘A collaborative optimization method for the sintering schedule of ternary cathode materials was proposed under microscopic coupling constraints.An oxygen vacancy concentration prediction model based on microscopic thermodynamics and a growth kinetics model based on neural networks were established.Then,optimization formulations were constructed in three stages to obtain an optimal sintering schedule that minimized energy consumption for different requirements.Simulations demonstrate that the models accurately predict the oxygen vacancy concentrations and grain size,with root mean square errors of approximately 5%and 3%,respectively.Furthermore,the optimized sintering schedule not only meets the required quality standards but also reduces sintering time by 12.31%and keeping temperature by 11.96%.This research provides new insights and methods for the preparation of ternary cathode materials.
基金supported by the National Natural Science Foundation of China(Nos.52122408,52071023)the Program for Science&Technology Innovation Talents in the University of Henan Province(No.22HASTIT1006)+2 种基金the Program for Central Plains Talents(No.ZYYCYU202012172)the Ministry of Education,Singapore(No.RG70/20)the Opening Project of National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials,Henan University of Science and Technology(No.HKDNM201906).
文摘Although lithium-ion batteries(LIBs)currently dominate a wide spectrum of energy storage applications,they face challenges such as fast cycle life decay and poor stability that hinder their further application.To address these limitations,element doping has emerged as a prevalent strategy to enhance the discharge capacity and extend the durability of Li-Ni-Co-Mn(LNCM)ternary compounds.This study utilized a machine learning-driven feature screening method to effectively pinpoint four key features crucially impacting the initial discharge capacity(IC)of Li-Ni-Co-Mn(LNCM)ternary cathode materials.These features were also proved highly predictive for the 50^(th)cycle discharge capacity(EC).Additionally,the application of SHAP value analysis yielded an in-depth understanding of the interplay between these features and discharge performance.This insight offers valuable direction for future advancements in the development of LNCM cathode materials,effectively promoting this field toward greater efficiency and sustainability.
基金supported by the National Natural Science Foundation of China(No.52072217)the National Key Research and Development Program of China(No.2022YFB3807700)+2 种基金the Joint Funds of the Hubei Natural Science Foundation Innovation and Development(No.2022CFD034)Hubei Natural Science Foundation Innovation Group Project(No.2022CFA020)the Major Technological Innovation Project of Hubei Science and Technology Department(No.2019AAA164).
文摘With the rapid development of new energy and the high proportion of new energy connected to the grid,energy storage has become the leading technology driving significant adjustments in the global energy landscape.Electrochemical energy storage,as the most popular and promising energy storage method,has received extensive attention.Currently,the most widely used energy storage method is metal-ion secondary batteries,whose performance mainly depends on the cathode material.Prussian blue analogues(PBAs)have a unique open framework structures that allow quick and reversible insertion/extraction of metal ions such as Na^(+),K^(+),Zn^(2+),Li^(+)etc.,thus attracting widespread attention.The advantages of simple synthesis process,abundant resources,and low cost also distinguish it from its counterparts.Unfortunately,the crystal water and structural defects in the PBAs lattice that is generated during the synthesis process,as well as the low Na content,significantly affect their electrochemical performance.This paper focuses on PBAs’synthesis methods,crystal structure,modification strategies,and their potential applications as cathode materials for various metal ion secondary batteries and looks forward to their future development direction.
基金supported by the National Natural Science Foundation of China(52202266 and 52403379).
文摘Full-manganese(Mn)Li-rich materials have gained attention owing to the limited availability of cobalt-or nickel-based cathodes commonly used in batteries,which greatly restricts their potential for large-scale application.However,their practical implementation is hindered by the rapid voltage/capacity decay during cycling and the long-standing problem of redox kinetics due to their poor ionic conductivity based on the ordered honeycomb structure.In this study,the kinetic and thermodynamic properties of intralayer disordered and ordered Li-rich full-Mn-based cathode materials were compared,demonstrating that the disordered R3m Li_(0.6)[Li_(0.2)Mn_(0.8)]O_(2)(D-LMO)delivers a significant advantage of rate capability over the ordered C2/m Li_(0.6)[Li_(0.2)Mn_(0.8)]O_(2)(O-LMO).Meanwhile,the D-LMO keeps superior capacity retention of up to 99%after 50 cycles under 25 mAg^(-1).In comparsion,the capacity retention of the O-LMO drops to just 70%,and its average discharge voltage is 0.2 V lower than that of the D-LMO.Herein,we conducted systematic density functional theory(DFT)simulations,focusing on the electronic structure modulation governing the voltage platform between the ordered and disordered phases.The ab initio molecular dynamics(AIMD)results indicated that the energy of the intralayer disordered structure fluctuates around the equilibrium position without any abrupt drops,demonstrating excellent stability.This study enhances the understanding of intralayer disordered full-Mn Li-rich material and provides insights into the design of low-cost,high-performance cathode materials for Li-ion batteries.
基金supported by Natural Science Foundation of Ningxia Province,China(No.2023AAC05047)Special Project for the Central-Guided Local Science and Technology Development(No.2024FRD05062)+1 种基金Graduate Student Innovation Project of North Minzu University(No.YCX24102)Ningxia Science and Technology Innovation Team for Key Materials and Devices in High-Performance Secondary Batteries(No.2024CXTD003).
文摘Although manganese-based oxide is regarded as a promising cathode material for zincion hybrid supercapacitors(ZHSCs),its practical application is hindered by slow zinc ion diffusion and the instability of MnO_(2).To overcome this obstacle,a δ-MnO_(2)/MXene heterostructure was created using a simple one-step process under gentle condition.The ZHSC was assembled using this heterostructure as the cathode,activated carbon(AC)as the anode and 2 mol·L−1 ZnSO_(4) as the electrolyte.The resultingδ-MnO_(2)/MXene//ZnSO4//AC ZHSC shows a maximum specific capacitance of 97.4 F·g^(−1) and an energy density of 32.27 Wh·kg^(−1) at the best cathode-to-anode mass ratio.Ex situ characterizations reveal the reversible energy storage mechanism combing Zn^(2+)insertion/extraction in the cathode,ion adsorption and desorption on the anode surface,and partial reversible formation and dissolution of Zn_(4)SO_(4)(OH)_(6)·5H_(2)O(ZHS)components on both electrodes.Adding of Mn^(2+)to the electrolyte reduced Mn dissolution,improving the ZHSC’s specific capacitance and energy density to 140.4 F·g^(−1) and 49.36 Wh·kg^(−1),respectively,while also enhancing its rate performance and cyclability.The improved electrochemical reaction kinetics was verified through various tests.The results suggest that the δ-MnO_(2)/MXene heterostructure has great potential as a high-performance cathode material for ZHSCs.
基金Project(21473258)supported by the National Natural Science Foundation of ChinaProject(13JJ1004)supported by the Distinguished Young Scientists of Hunan Province,ChinaProject(NCET-11-0513)supported by the New Century Excellent Talents in University,China
文摘Li[NixCoyMn2]O2（0.6≤x≤0.8） cathode materials with a typical hexagonal α-NaFeO2 structure were prepared utilizing a co-precipitation method.It is found that the ratio of peak intensities of（003） to（104） observed from X-ray diffraction（XRD）increases with decreasing the Ni content or increasing the Co content.The scanning electron microscopy（SEM） images reveal that the small primary particles are agglomerated to form the secondary ones.As the Mn content increases,the primary and secondary particles become larger and the resulted particle size for the Li[Ni（0.6）Co（0.2）Mn（0.2）]O2 is uniformly distributed in the range of100-300 nm.Although the initial discharge capacity of the Li/Li[NixCoyMn2]O2 cells reduces with decreasing the Ni content,the cyclic performance and rate capability are improved with higher Mn or Co content.The Li[Ni（0.6）Co（0.2）Mn（0.2）]O2 can deliver excellent cyclability with a capacity retention of 97.1%after 50 cycles.
基金Project (51162026) supported by the National Natural Science Foundation of ChinaProjects (20100480949, 201104509) supported by China Postdoctoral Science FoundationProject (133274341015501) supported by Postdoctoral Science Foundation of Central South University, China
文摘Li3V2（PO4）3 precursor was obtained with V2Os.nH2O , LiOH＇H2O, NH4H2PO4 and sucrose as starting materials by grinding-sol-gel method, and then the monoclinic-typed Li3Vz（PO4）3 cathode material was prepared by sintering the amorphous Li3V2（PO4）3. The as-sintered samples were investigated by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, N2 adsorption-desorption and electrochemical measurement. It is found that Li3Vz（PO4）3 sintered at 700 ℃ possesses good wormhole-like mesoporous structure with the largest specific surface area of 188 cmZ/g, and the smallest pore size of 9.3 nm. Electrochemical test reveals that the initial discharge capacity of the 700 ℃ sintered sample is 155.9 mA.h/g at the rate of 0.2C, and the capacity retains 154 mA.h/g after 50 cycles, exhibiting a stable discharge capacity at room temperature.
基金supported by the National Natural Science Foundation of China(Nos.U1564206,U1764258)the National Key R&D Program of China(No.2018YFB0105700)+1 种基金the support from China Scholarship Council(No.201806030115)supported by the Department of Energy(DOE),Office of Electricity(OE)at Oak Ridge National Laboratory managed by UL-Battelle LLC under contract DE-AC05-00OR22725。
文摘In this paper,overcharge behaviors and thermal runaway(TR)features of large format lithium-ion(Liion)cells with different cathode materials(LiFePO4(LFP),Li[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_(2)(NCM111),Li[Ni_(0.6)Co_(0.2)Mn_(0.2)]O_(2)(NCM622)and Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(NCM811))were investigated.The results showed that,under the same overcharge condition,the TR of LFP Li-ion cell occurred earlier compared with the NCM Li-ion cells,indicating its poor overcharge tolerance and high TR risk.However,when TR occurred,LFP Li-ion cell exhibited lower maximum temperature and mild TR response.All NCM Liion cells caught fire or exploded during TR,while the LFP Li-ion cell only released a large amount of smoke without fire.According to the overcharge behaviors and TR features,a safety assessment score system was proposed to evaluate the safety of the cells.In short,NCM Li-ion cells have better performance in energy density and overcharge tolerance(or low TR risk),while LFP Li-ion cell showed less severe response to overcharging(or less TR hazards).For NCM Li-ion cells,as the ratio of nickel in cathode material increases,the thermal stability of the cathode materials becomes poorer,and the TR hazards increase.Such a comparison study on large format Li-ion cells with different cathode materials can provide deeper insights into the overcharge behaviors and TR features,and provide guidance for engineers to reasonably choose battery materials in automotive applications.
