As lithium-ion batteries(LIBs)continue to evolve toward lower costs and higher energy densities,their potential safety risks have become increasingly apparent.Incidents such as explosions at energy storage facilities,...As lithium-ion batteries(LIBs)continue to evolve toward lower costs and higher energy densities,their potential safety risks have become increasingly apparent.Incidents such as explosions at energy storage facilities,fires in electric vehicles,and building fires ignited by charging two-wheeled vehicles have been occurring with alarming frequency,often resulting in significant casualties and injuries.Conducting indepth investigations into thermal runaway(TR)incidents in LIBs can significantly reduce the risk of future occurrences.However,current investigations into LIB fire and explosion incidents face challenges due to the difficulty of conducting in-depth analyses and the lack of a robust theoretical framework to guide these investigations.To enhance the effectiveness of in-depth investigations into battery fire and explosion incidents and to address the lack of theoretical guidance,this paper is the first to systematically examine the conservation and flow patterns of elements during the TR process of LIBs.The analysis reveals that during TR,the gas products generated include approximately 1.5 g of H_(2),23.6 g of CO,88.4 g of CO_(2),8.9 g of C_(2)H_(4),7.3 g of CH_(4),3.7 g of C_(2)H_(6),and 82 g of electrolyte vapor.After TR,the solid compounds formed consist of approximately 2.5 g of LiF,29–92.2 g of elemental Ni/Co/Mn,11.4 g of Li_(2)CO_(3),200.6 g of graphite,1.4 g of NiO,29.6 g of MnO,30.1 g of CoO,67 g of elemental Cu,0.03 g of LiNiO_(2),and 4.3 g of LiAlO_(2).Importantly,the energy released from reactions forming solid compounds during TR surpasses that from gas-forming reactions.This investigation represents the first application of Hess’s law to verify the conservation of elements during the TR process of lithium-ion batteries.The proposed methodology is also applicable to other types of energy storage batteries,effectively advancing techniques for comprehensively investigating lithium battery fire and explosion incidents.展开更多
Blade batteries are extensively used in electric vehicles,but unavoidable thermal runaway is an inherent threat to their safe use.This study experimentally investigated the mechanism underlying thermal runaway propaga...Blade batteries are extensively used in electric vehicles,but unavoidable thermal runaway is an inherent threat to their safe use.This study experimentally investigated the mechanism underlying thermal runaway propagation within a blade battery by using a nail to trigger thermal runaway and thermocouples to track its propagation inside a cell.The results showed that the internal thermal runaway could propagate for up to 272 s,which is comparable to that of a traditional battery module.The velocity of the thermal runaway propagation fluctuated between 1 and 8 mm s^(-1),depending on both the electrolyte content and high-temperature gas diffusion.In the early stages of thermal runaway,the electrolyte participated in the reaction,which intensified the thermal runaway and accelerated its propagation.As the battery temperature increased,the electrolyte evaporated,which attenuated the acceleration effect.Gas diffusion affected thermal runaway propagation through both heat transfer and mass transfer.The experimental results indicated that gas diffusion accelerated the velocity of thermal runaway propagation by 36.84%.We used a 1D mathematical model and confirmed that convective heat transfer induced by gas diffusion increased the velocity of thermal runaway propagation by 5.46%-17.06%.Finally,the temperature rate curve was analyzed,and a three-stage mechanism for internal thermal runaway propagation was proposed.In Stage I,convective heat transfer from electrolyte evaporation locally increased the temperature to 100℃.In Stage II,solid heat transfer locally increases the temperature to trigger thermal runaway.In StageⅢ,thermal runaway sharply increases the local temperature.The proposed mechanism sheds light on the internal thermal runaway propagation of blade batteries and offers valuable insights into safety considerations for future design.展开更多
Typical application scenarios,such as vehicle to grid(V2G)and frequency regulation,have imposed significant long-life demands on lithium-ion batteries.Herein,we propose an advanced battery life-extension method employ...Typical application scenarios,such as vehicle to grid(V2G)and frequency regulation,have imposed significant long-life demands on lithium-ion batteries.Herein,we propose an advanced battery life-extension method employing bidirectional pulse charging(BPC)strategy.Unlike traditional constant current charging methods,BPC strategy not only achieves comparable charging speeds but also facilitates V2G frequency regulation simultaneously.It significantly enhances battery cycle ampere-hour throughput and demonstrates remarkable life extension capabilities.For this interesting conclusion,adopting model identification and postmortem characterization to reveal the life regulation mechanism of BPC:it mitigates battery capacity loss attributed to loss of lithium-ion inventory(LLI)in graphite anodes by intermittently regulating the overall battery voltage and anode potential using a negative charging current.Then,from the perspective of internal side reaction,the life extension mechanism is further revealed as inhibition of solid electrolyte interphase(SEI)and lithium dendrite growth by regulating voltage with a bidirectional pulse current,and a semi-empirical life degradation model combining SEI and lithium dendrite growth is developed for BPC scenarios health management,the model parameters are identified by genetic algorithm with the life simulation exhibiting an accuracy exceeding 99%.This finding indicates that under typical rate conditions,adaptable BPC strategies can extend the service life of LFP battery by approximately 123%.Consequently,the developed advanced BPC strategy offers innovative perspectives and insights for the development of long-life battery applications in the future.展开更多
Thermal runaway(TR)is a critical issue hindering the large-scale application of lithium-ion batteries(LIBs).Understanding the thermal safety behavior of LIBs at the cell and module level under different state of charg...Thermal runaway(TR)is a critical issue hindering the large-scale application of lithium-ion batteries(LIBs).Understanding the thermal safety behavior of LIBs at the cell and module level under different state of charges(SOCs)has significant implications for reinforcing the thermal safety design of the lithium-ion battery module.This study first investigates the thermal safety boundary(TSB)correspondence at the cells and modules level under the guidance of a newly proposed concept,safe electric quantity boundary(SEQB).A reasonable thermal runaway propagation(TRP)judgment indicator,peak heat transfer power(PHTP),is proposed to predict whether TRP occurs.Moreover,a validated 3D model is used to quantitatively clarify the TSB at different SOCs from the perspective of PHTP,TR trigger temperature,SOC,and the full cycle life.Besides,three different TRP transfer modes are discovered.The interconversion relationship of three different TRP modes is investigated from the perspective of PHTP.This paper explores the TSB of LIBs under different SOCs at both cell and module levels for the first time,which has great significance in guiding the thermal safety design of battery systems.展开更多
Cell-to-cell variations(CtCV) compromise the electrochemical performance of battery packs, yet the evolutional mechanism and quantitative impacts of CtCV on the pack's fast-charging performance remain unexplored. ...Cell-to-cell variations(CtCV) compromise the electrochemical performance of battery packs, yet the evolutional mechanism and quantitative impacts of CtCV on the pack's fast-charging performance remain unexplored. This knowledge gap is vital for the proliferation of electric vehicles. This study underlies the relationship between CtCV and charging performance by assessing the pack's charge speed, final electric quantity, and temperature consistency. Cell variations and pack status are depicted using 2D parameter diagrams, and an m PnS configured pack model is built upon a decomposed electrode cell model.Variations in three single electric parameters, i.e., capacity(Q), electric quantity(E), and internal resistance(R), and their dual interactions, i.e., E-Q and R-Q, are analyzed carefully. The results indicate that Q variations predominantly affect the final electric quantity of the pack, while R variations impact the charge speed most. With incremental variances in cell parameters, the pack's fast-charging capability first declines linearly and then deteriorates sharply as variations intensify. This research elucidates the correlations between pack charging capabilities and cell variations, providing essential insights for optimizing cell sorting and assembly, battery management design, and charging protocol development for battery packs.展开更多
Internal short circuit(ISC)is the major failure problem for the safe application of lithium-ion batteries,especially for the batteries with high energy density.However,how to quantify the hazard aroused by the ISC,and...Internal short circuit(ISC)is the major failure problem for the safe application of lithium-ion batteries,especially for the batteries with high energy density.However,how to quantify the hazard aroused by the ISC,and what kinds of ISC will lead to thermal runaway are still unclear.This paper investigates the thermal-electrical coupled behaviors of ISC,using batteries with Li(Ni_(1/3)CO_(1/3)Mn_(1/3))O_(2) cathode and composite separator.The electrochemical impedance spectroscopy of customized battery that has no LiPF6 salt is utilized to standardize the resistance of ISC.Furthermore,this paper compares the thermal-electrical coupled behaviors of the above four types of ISC at different states-of-charge.There is an area expansion phenomenon for the aluminum-anode type of ISC.The expansion effect of the failure area directly links to the melting and collapse of separator,and plays an important role in further evolution of thermal runaway.This work provides guidance to the development of the ISC models,detection algorithms,and correlated countermeasures.展开更多
Thermal runaway is a critical issue for the large application of lithium-ion batteries.Exothermic reactions between lithiated graphite and electrolyte play a crucial role in the thermal runaway of lithium-ion batterie...Thermal runaway is a critical issue for the large application of lithium-ion batteries.Exothermic reactions between lithiated graphite and electrolyte play a crucial role in the thermal runaway of lithium-ion batteries.However,the role of each component in the electrolyte during the exothermic reactions with lithiated graphite has not been fully understood.In this paper,the exothermic reactions between lithiated graphite and electrolyte of lithium-ion battery are investigated through differential scanning calorimetry(DSC) and evolved gas analysis.The lithiated graphite in the presence of electrolyte exhibit three exothermic peaks during DSC test.The reactions between lithiated graphite and LiPF_(6) and ethylene carbonate are found to be responsible for the first two exothermic peaks,while the third exothermic peak is attributed to the reaction between lithiated graphite and binder.In contrast,diethylene carbonate and ethyl methyl carbonate contribute little to the total heat generation of graphite-electrolyte reactions.The reaction mechanism between lithiated graphite and electrolyte,including the major reaction equations and gas products,are summarized.Finally,DSC tests on samples with various amounts of electrolyte are performed to clarify the quantitative relationship between lithiated graphite and electrolyte during the exothermic reactions.2.5 mg of lithiated graphite (Li_(0.8627)C_(6)) can fully react with around 7.2 mg electrolyte,releasing a heat generation of 2491 J g^(-1).The results presented in this study can provide useful guidance for the safety improvement of lithium-ion batteries.展开更多
Structurally compact battery packs significantly improve the driving range of electric vehicles.Technologies like Cell-to-Pack increase energy density by 15%-20%.However,the safety implications of multiple tightly-pac...Structurally compact battery packs significantly improve the driving range of electric vehicles.Technologies like Cell-to-Pack increase energy density by 15%-20%.However,the safety implications of multiple tightly-packed battery cells still require in-depth research.This paper studies thermal runaway propagation behavior in a Cell-to-Pack system and assesses propagation speed relative to other systems.The investigation includes temperature response,extent of battery damage,pack structure deformation,chemical analysis of debris,and other considerations.Results suggest three typical patterns for the thermal runaway propagation process:ordered,disordered,and synchronous.The synchronous propagation pattern displayed the most severe damage,indicating energy release is the largest under the synchronous pattern.This study identifies battery deformation patterns,chemical characteristics of debris,and other observed factors that can both be applied to identify the cause of thermal runaway during accident investigations and help promote safer designs of large battery packs used in large-scale electric energy storage systems.展开更多
Fluorinated electrolytes possess good antioxidant capacity that provides high compatibility to high-voltage cathode and flame retardance;thus,they are considered as a promising solution for advanced lithium-ion batter...Fluorinated electrolytes possess good antioxidant capacity that provides high compatibility to high-voltage cathode and flame retardance;thus,they are considered as a promising solution for advanced lithium-ion batteries carrying both high-energy density and high safety.Moreover,the fluorinated electrolytes are widely used to form stable electrolyte interphase,due to their chemical reactivity with lithiated graphite or lithium.However,the influence of this reactivity on the thermal safety of batteries is seldom discussed.Herein,we demonstrate that the flame-retardant fluorinated electrolytes help to reduce the flammability,while the lithium-ion batteries with flame-retardant fluorinated electrolytes still undergo thermal runaway and disclose their different thermal runaway pathway from that of battery with conventional electrolyte.The reduction in fluorinated components(e.g.,LiPF 6 and fluoroethylene carbonate(FEC))by fully lithiated graphite accounts for a significant heat release during battery thermal runaway.The 13%of total heat is sufficient to trigger the chain reactions during battery thermal runaway.This study deepens the understanding of the thermal runaway mechanism of lithium-ion batteries employing flame-retardant fluorinated electrolytes,providing guidance on the concept of electrolyte design for safer lithium-ion batteries.展开更多
The safety monitoring of lithium-ion batteries(LIBs) is of great significance for realizing all-climate and full-lifespan battery management. In-situ measurement of anode potential with implanted reference electrodes(...The safety monitoring of lithium-ion batteries(LIBs) is of great significance for realizing all-climate and full-lifespan battery management. In-situ measurement of anode potential with implanted reference electrodes(REs) has proven to be effective to monitor and avoid the occurrence of severe side reactions like Li plating to ensure the safe and fast charging. However, the intrinsic measurement errors caused by local blocking effects, which also can be referred to as potential artefacts, are seldom taken into consideration in existing studies, yet they highly dominate the correctness of conclusions inferred from REs. In this study, aiming at exploring the physical origin of the measurement errors and ensure reliable potential monitoring, electrochemical and post-mortem tests are conducted using commercial pouch cells with implanted REs. Corresponding electrochemical model which describes the blocking effects, is established to validate the abnormal absence of lithium plating that predicted by measured anode potentials under various charging rates. Theoretical derivation is further presented to explain the error sources, which can be attributed to increased local liquid potential of the RE position. Most importantly, with the guidance of error analysis, a novel parameter-independent error correction method for RE measurements is proposed for the first time, which is proven to be adequate to estimate the real anode potentials and deduce the critical C-rate of Li plating with extra safety margin. After error correction, the resulting critical C-rates are all within the range of 0.55 ± 0.03 C, which is close to the C-rate of 0.6–0.7 C obtained from experiments. In addition, this error correction method can be performed conveniently with only some simple RE measurements of polarization voltages, totally independent of battery electrochemical and geometric parameters. This study provides highly practical error correction method for RE measurements in real LIBs, substantially facilitating the fast diagnosis and safety evaluation of Li plating during charging of LIBs.展开更多
As the energy density of battery increases rapidly,lithium-ion batteries(LIBs)are facing serious safety issue with thermal runaway,which largely limits the large-scale applications of high-energy-density LIBs.It is ge...As the energy density of battery increases rapidly,lithium-ion batteries(LIBs)are facing serious safety issue with thermal runaway,which largely limits the large-scale applications of high-energy-density LIBs.It is generally agreed that the chemical crosstalk between the cathode and anode leads to thermal runaway of LIBs.Herein,a multifunctional high safety electrolyte is designed with synergistic construction of cathode electrolyte interphase and capture of reactive free radicals to limit the intrinsic pathway of thermal runaway.The cathode electrolyte interphase not only resists the gas attack from the anode but suppresses the parasitic side reactions induced by electrolyte.And the function of free radical capture has the ability of reducing heat release from thermal runaway of battery.The dual strategy improves the intrinsic safety of battery prominently that the triggering temperature of thermal runaway is increased by 24.4℃and the maximum temperature is reduced by 177.7℃.Simultaneously,the thermal runaway propagation in module can be self-quenched.Moreover,the electrolyte design balances the trade-off of electrochemical and safety performance of high-energy batteries.The capacity retention of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)|graphite pouch cell has been significantly increased from 53.85%to 97.05%with higher coulombic efficiency of 99.94%at operating voltage extended up to 4.5 V for 200 cycles.Therefore,this work suggests a feasible strategy to mitigate the safety risk of high-energy-density LIBs without sacrificing electrochemical performances.展开更多
Lithium-ion batteries with high-energy density are extensively commercialized in long-range electric vehicles. However, they are poor in thermal stability and pose fire or explosion, which has attracted the global att...Lithium-ion batteries with high-energy density are extensively commercialized in long-range electric vehicles. However, they are poor in thermal stability and pose fire or explosion, which has attracted the global attention. This study describes a new route to mitigate the battery thermal runaway(TR) hazard by poison agents. First, the self-destructive cell is built using the embedded poison layer. Then, the poisoning mechanism and paths are experimentally investigated at the material, electrode, and cell levels. Finally, the proposed route is verified by TR tests. The results show the TR hazard can be significantly reduced in the self-destructive cell based on a new reaction sequence regulation. Specifically, the maximum temperature of the self-destructive cell is more than 300℃ lower than that of the normal cell during TR. The drop in maximum temperature can reduce total heat release and the probability of TR propagation in the battery system, significantly improving battery safety.展开更多
There is an increasing demand for real-time data-driven fault diagnosis of lithium-ion batteries that can predict battery faults at an early stage to avoid safety issues and improve battery reliability.However,such pr...There is an increasing demand for real-time data-driven fault diagnosis of lithium-ion batteries that can predict battery faults at an early stage to avoid safety issues and improve battery reliability.However,such prediction methods require large amounts of data,generally obtained through experiments or during the operation phase,resulting in substantial economic and time efforts.In this context,generating realistic battery pack data that covers all sensor values a battery management system receives,as well as including fault models,is of particular interest and can mitigate the need to perform extensive laboratory testing.This paper focuses on the systematic development of a data generation platform capable of simulating a large scale of battery packs with random battery faults and generating big data for the following battery fault diagnostics.Initially,the electrical,thermal,and aging modeling of a battery pack is performed.After this,four types of faults,namely hard short circuit,soft short circuit,abnormal internal resistance,and abnormal contact resistance,are modeled using equivalent circuit models.To generate realistic data,both cell-to-cell variations and pack-level variations are considered.Variations included are,for example,the manufacturing quality,temperatures,aging processes,road conditions,state of charge,and fault severity.By combining the battery pack models,fault models,and the different variations through Monte Carlo simulations,a large data set representing different packs with varying levels of inconsistencies is generated.展开更多
The morphology of plated lithium(MPL)metal on graphite anodes,traditionally described as“moss-like”and“dendrite-like”,exert a substantial negative influence on the performance of lithium-ion batteries(LIBs)by modu...The morphology of plated lithium(MPL)metal on graphite anodes,traditionally described as“moss-like”and“dendrite-like”,exert a substantial negative influence on the performance of lithium-ion batteries(LIBs)by modulating the metal-electrolyte interface and side reaction rates.However,a systematic and quantitative analysis of MPL is lacking,impeding effective evaluation and manipulation of this detrimental issue.In this study,we transition from a qualitative analysis to a quantitative one by conducting a detailed examination of the MPL.Our findings reveal that slender lithium dendrites reduces the lifespan and safety of LIB by increasing the side reaction rates and promoting the formation of dead lithium.To further evaluate the extent of the detrimental effect of MPL,we propose the specific surface area(SSA)as a critical metric,and develop an in situ method integrating expansion force and electrochemical impedance spectroscopy to estimate SSA.Finally,we introduce a pulse current protocol to manipulate hazardous MLP.Phase field model simulations and experiments demonstrate that this protocol significantly enhances the reversibility of plated lithium.This research offers a novel morphological perspective on lithium plating,providing a more detailed fundamental understanding that facilitates effective evaluation and manipulation of plated lithium,thereby enhancing the safety and extending the cycle life of LIBs.展开更多
Despite the widespread utilization of Lithium-ion batteries(LIBs),concerns regarding safety during operation persist owing to accidents and potential risks of fires and explosions.To comprehend the thermal dynamics th...Despite the widespread utilization of Lithium-ion batteries(LIBs),concerns regarding safety during operation persist owing to accidents and potential risks of fires and explosions.To comprehend the thermal dynamics that underlie severe LIB incidents,calorimetry tests have been prevalently employed for over three decades to examine the exothermic/endothermic behavior,reaction kinetics,and thermal interactions among LIB materials.There exists a substantial volume of calorimetry test results on various LIB electrodes,electrolytes,and other components.However,this data showcases low consistency,yielding an unreliable database that obstructs a thorough understanding of LIB thermal behavior.In this research,a comparative analysis of differential scanning calorimetry(DSC)results from materials utilized in the most commercialized LIB systems is conducted.The analysis unveils notable discrepancies in DSC data amassed by different researchers,identifies five predominant causes of data inconsistency,proposes a standardized DSC operational procedure,and generates a set of self-consistent data.Subsequently,an intrinsic safety spectrum is delineated and compared with X-ray diffraction(XRD)outcomes to elucidate the correlation between the crystal lattice structure and the thermal behavior of the material.This work aids in the formation of a comparative DSC database,utilizing the vast but inconsistent literature data.Moreover,it clarifies the linkage between the material structure and thermal behavior,facilitating data-driven thermal analysis of LIBs.展开更多
With the continuous development of the electrification industry,the development of high-specific batteries has attracted much attention.However,the safety of lithiumion batteries is currently unable to meet the market...With the continuous development of the electrification industry,the development of high-specific batteries has attracted much attention.However,the safety of lithiumion batteries is currently unable to meet the market demand due to poor thermal stability.Solving the thermal issues is crucial to improve battery safety.Ethylene carbonate(EC)not only plays an important interfacial film-forming role,but also poses safety risks in terms of reactivity.In this work,we conducted a series of gradient experiments utilizing different EC amounts and verified the effect of reducing EC on battery performance.A strategy is also proposed to design a new electrolyte.Ethyl methyl carbonate(EMC)is used instead of EC as the main solvent to improve the thermal safety of the battery,while salts and additives are used to dominate the film formation to improve the cycling stability of the battery under high voltages(4.5 V,~90%after 200 cycles).This work paves a new avenue for the development of novel electrolyte systems.展开更多
To investigate the effect of different states of charge(SOC)on the thermal runaway(TR)propagation behaviors within lithium-ion-batteries based energy storage modules,an experimental setup was developed to conduct fail...To investigate the effect of different states of charge(SOC)on the thermal runaway(TR)propagation behaviors within lithium-ion-batteries based energy storage modules,an experimental setup was developed to conduct failure propagation tests on battery modules at an SOC of 97%,85%,and 50%.The result indicates that an increase in the SOC of batteries can decrease the TR trigger temperature,making batteries trigger TR earlier and reducing the average failure propagation time between two adjacent cells.In addition,the failure propagation tests reveal that at higher SOCs,the TR reaction becomes more violent,the maximal reaction temperature is also much higher,and the damage to the battery module is severe.Compared to the battery module with 97%SOC,the TR trigger time of the battery module with 50%SOC was postponed by approximately 57.8%.Meanwhile,the average failure propagation time got prolonged by approximately 36.0%.Thus,this study can provide references for the thermal safety design of energy-storage battery modules.展开更多
Lithium-ion(Li-ion)cells degrade after repeated cycling and the cell capacity fades while its resistance increases.Degra-dation of Li-ion cells is caused by a variety of physical and chemical mechanisms and it is stro...Lithium-ion(Li-ion)cells degrade after repeated cycling and the cell capacity fades while its resistance increases.Degra-dation of Li-ion cells is caused by a variety of physical and chemical mechanisms and it is strongly influenced by factors including the electrode materials used,the working conditions and the battery temperature.At present,charging voltage curve analysis methods are widely used in studies of battery characteristics and the constant current charging voltage curves can be used to analyze battery aging mechanisms and estimate a battery’s state of health(SOH)via methods such as incremental capacity(IC)analysis.In this paper,a method to fit and analyze the charging voltage curve based on a neural network is proposed and is compared to the existing point counting method and the polynomial curve fitting method.The neuron parameters of the trained neural network model are used to analyze the battery capacity relative to the phase change reactions that occur inside the batteries.This method is suitable for different types of batteries and could be used in battery management systems for online battery modeling,analysis and diagnosis.展开更多
LiFePO_(4)(LFP)lithium-ion batteries have gained widespread use in electric vehicles due to their safety and longevity,but thermal runaway(TR)incidents still have been reported.This paper explores the TR characteristi...LiFePO_(4)(LFP)lithium-ion batteries have gained widespread use in electric vehicles due to their safety and longevity,but thermal runaway(TR)incidents still have been reported.This paper explores the TR characteristics and modeling of LFP batteries at different states of charge(SOC).Adiabatic tests reveal that TR severity increases with SOC,and five stages are identified based on battery temperature evolution.Reaction kinetics parameters of exothermic reactions in each TR stage are extracted,and TR models for LFP batteries are established.The models accurately simulate TR behaviors at different SOCs,and the simulated TR characteristic temperatures also agree well with the experimental results,with errors of TR characteristic temperatures less than 3%.The prediction errors of TR characteristic temperatures under oven test conditions are also less than 1%.The results provide a comprehensive understanding of TR in LFP batteries,which is useful for battery safety design and optimization.展开更多
Further applications of electric vehicles(EVs)and energy storage stations are limited because of the thermal sensitivity,volatility,and poor durability of lithium-ion batteries(LIBs),especially given the urgent requir...Further applications of electric vehicles(EVs)and energy storage stations are limited because of the thermal sensitivity,volatility,and poor durability of lithium-ion batteries(LIBs),especially given the urgent requirements for all-climate utilization and fast charging.This study comprehensively reviews the thermal characteristics and management of LIBs in an all-temperature area based on the performance,mechanism,and thermal management strategy levels.展开更多
基金supported by the National Natural Science Foundation of China(52106284,52422609)the Natural Science Foundation of Hebei Province(B2021507001)Key Research Special Project of CPPU(ZDZX202501)。
文摘As lithium-ion batteries(LIBs)continue to evolve toward lower costs and higher energy densities,their potential safety risks have become increasingly apparent.Incidents such as explosions at energy storage facilities,fires in electric vehicles,and building fires ignited by charging two-wheeled vehicles have been occurring with alarming frequency,often resulting in significant casualties and injuries.Conducting indepth investigations into thermal runaway(TR)incidents in LIBs can significantly reduce the risk of future occurrences.However,current investigations into LIB fire and explosion incidents face challenges due to the difficulty of conducting in-depth analyses and the lack of a robust theoretical framework to guide these investigations.To enhance the effectiveness of in-depth investigations into battery fire and explosion incidents and to address the lack of theoretical guidance,this paper is the first to systematically examine the conservation and flow patterns of elements during the TR process of LIBs.The analysis reveals that during TR,the gas products generated include approximately 1.5 g of H_(2),23.6 g of CO,88.4 g of CO_(2),8.9 g of C_(2)H_(4),7.3 g of CH_(4),3.7 g of C_(2)H_(6),and 82 g of electrolyte vapor.After TR,the solid compounds formed consist of approximately 2.5 g of LiF,29–92.2 g of elemental Ni/Co/Mn,11.4 g of Li_(2)CO_(3),200.6 g of graphite,1.4 g of NiO,29.6 g of MnO,30.1 g of CoO,67 g of elemental Cu,0.03 g of LiNiO_(2),and 4.3 g of LiAlO_(2).Importantly,the energy released from reactions forming solid compounds during TR surpasses that from gas-forming reactions.This investigation represents the first application of Hess’s law to verify the conservation of elements during the TR process of lithium-ion batteries.The proposed methodology is also applicable to other types of energy storage batteries,effectively advancing techniques for comprehensively investigating lithium battery fire and explosion incidents.
基金supported by the National Key R&D Program-Strategic Scientific and Technological Innovation Cooperation(Grant No.2022YFE0207900)the National Natural Science Foundation of China(Grant Nos.51706117,52076121)。
文摘Blade batteries are extensively used in electric vehicles,but unavoidable thermal runaway is an inherent threat to their safe use.This study experimentally investigated the mechanism underlying thermal runaway propagation within a blade battery by using a nail to trigger thermal runaway and thermocouples to track its propagation inside a cell.The results showed that the internal thermal runaway could propagate for up to 272 s,which is comparable to that of a traditional battery module.The velocity of the thermal runaway propagation fluctuated between 1 and 8 mm s^(-1),depending on both the electrolyte content and high-temperature gas diffusion.In the early stages of thermal runaway,the electrolyte participated in the reaction,which intensified the thermal runaway and accelerated its propagation.As the battery temperature increased,the electrolyte evaporated,which attenuated the acceleration effect.Gas diffusion affected thermal runaway propagation through both heat transfer and mass transfer.The experimental results indicated that gas diffusion accelerated the velocity of thermal runaway propagation by 36.84%.We used a 1D mathematical model and confirmed that convective heat transfer induced by gas diffusion increased the velocity of thermal runaway propagation by 5.46%-17.06%.Finally,the temperature rate curve was analyzed,and a three-stage mechanism for internal thermal runaway propagation was proposed.In Stage I,convective heat transfer from electrolyte evaporation locally increased the temperature to 100℃.In Stage II,solid heat transfer locally increases the temperature to trigger thermal runaway.In StageⅢ,thermal runaway sharply increases the local temperature.The proposed mechanism sheds light on the internal thermal runaway propagation of blade batteries and offers valuable insights into safety considerations for future design.
基金supported by the National Natural Science Foundation of China(52177217)。
文摘Typical application scenarios,such as vehicle to grid(V2G)and frequency regulation,have imposed significant long-life demands on lithium-ion batteries.Herein,we propose an advanced battery life-extension method employing bidirectional pulse charging(BPC)strategy.Unlike traditional constant current charging methods,BPC strategy not only achieves comparable charging speeds but also facilitates V2G frequency regulation simultaneously.It significantly enhances battery cycle ampere-hour throughput and demonstrates remarkable life extension capabilities.For this interesting conclusion,adopting model identification and postmortem characterization to reveal the life regulation mechanism of BPC:it mitigates battery capacity loss attributed to loss of lithium-ion inventory(LLI)in graphite anodes by intermittently regulating the overall battery voltage and anode potential using a negative charging current.Then,from the perspective of internal side reaction,the life extension mechanism is further revealed as inhibition of solid electrolyte interphase(SEI)and lithium dendrite growth by regulating voltage with a bidirectional pulse current,and a semi-empirical life degradation model combining SEI and lithium dendrite growth is developed for BPC scenarios health management,the model parameters are identified by genetic algorithm with the life simulation exhibiting an accuracy exceeding 99%.This finding indicates that under typical rate conditions,adaptable BPC strategies can extend the service life of LFP battery by approximately 123%.Consequently,the developed advanced BPC strategy offers innovative perspectives and insights for the development of long-life battery applications in the future.
基金supported by the National Natural Science Foundation of China(No.U20A20310 and No.52176199)sponsored by the Program of Shanghai Academic/Technology Research Leader(No.22XD1423800)。
文摘Thermal runaway(TR)is a critical issue hindering the large-scale application of lithium-ion batteries(LIBs).Understanding the thermal safety behavior of LIBs at the cell and module level under different state of charges(SOCs)has significant implications for reinforcing the thermal safety design of the lithium-ion battery module.This study first investigates the thermal safety boundary(TSB)correspondence at the cells and modules level under the guidance of a newly proposed concept,safe electric quantity boundary(SEQB).A reasonable thermal runaway propagation(TRP)judgment indicator,peak heat transfer power(PHTP),is proposed to predict whether TRP occurs.Moreover,a validated 3D model is used to quantitatively clarify the TSB at different SOCs from the perspective of PHTP,TR trigger temperature,SOC,and the full cycle life.Besides,three different TRP transfer modes are discovered.The interconversion relationship of three different TRP modes is investigated from the perspective of PHTP.This paper explores the TSB of LIBs under different SOCs at both cell and module levels for the first time,which has great significance in guiding the thermal safety design of battery systems.
基金supported by the National Natural Science Foundation of China under No. 52177217the Postdoctoral Innovative Talents Support Program under No. BX20240232。
文摘Cell-to-cell variations(CtCV) compromise the electrochemical performance of battery packs, yet the evolutional mechanism and quantitative impacts of CtCV on the pack's fast-charging performance remain unexplored. This knowledge gap is vital for the proliferation of electric vehicles. This study underlies the relationship between CtCV and charging performance by assessing the pack's charge speed, final electric quantity, and temperature consistency. Cell variations and pack status are depicted using 2D parameter diagrams, and an m PnS configured pack model is built upon a decomposed electrode cell model.Variations in three single electric parameters, i.e., capacity(Q), electric quantity(E), and internal resistance(R), and their dual interactions, i.e., E-Q and R-Q, are analyzed carefully. The results indicate that Q variations predominantly affect the final electric quantity of the pack, while R variations impact the charge speed most. With incremental variances in cell parameters, the pack's fast-charging capability first declines linearly and then deteriorates sharply as variations intensify. This research elucidates the correlations between pack charging capabilities and cell variations, providing essential insights for optimizing cell sorting and assembly, battery management design, and charging protocol development for battery packs.
基金supported by the Ministry of Science and Technology of China under the contract No.2019YFE0100200the National Natural Science Foundation of China(grant Nos.51706117,52076121)funded by the Tsinghua Scholarship for Overseas Graduate Studies。
文摘Internal short circuit(ISC)is the major failure problem for the safe application of lithium-ion batteries,especially for the batteries with high energy density.However,how to quantify the hazard aroused by the ISC,and what kinds of ISC will lead to thermal runaway are still unclear.This paper investigates the thermal-electrical coupled behaviors of ISC,using batteries with Li(Ni_(1/3)CO_(1/3)Mn_(1/3))O_(2) cathode and composite separator.The electrochemical impedance spectroscopy of customized battery that has no LiPF6 salt is utilized to standardize the resistance of ISC.Furthermore,this paper compares the thermal-electrical coupled behaviors of the above four types of ISC at different states-of-charge.There is an area expansion phenomenon for the aluminum-anode type of ISC.The expansion effect of the failure area directly links to the melting and collapse of separator,and plays an important role in further evolution of thermal runaway.This work provides guidance to the development of the ISC models,detection algorithms,and correlated countermeasures.
基金supported by the Key-Area Research and Development Program of Guangdong Province (2020B090919004)the Ministry of Science and Technology of China (2019YFE0100200)+3 种基金the National Natural Science Foundation of China (52007099, 51706117, 52076121, 51877138)the Shanghai Science and Technology Development Fund (19QA1406200)the China Postdoctoral Science Foundation (2020M680550)the support from the “Shuimu Tsinghua Scholar Program” from Tsinghua University。
文摘Thermal runaway is a critical issue for the large application of lithium-ion batteries.Exothermic reactions between lithiated graphite and electrolyte play a crucial role in the thermal runaway of lithium-ion batteries.However,the role of each component in the electrolyte during the exothermic reactions with lithiated graphite has not been fully understood.In this paper,the exothermic reactions between lithiated graphite and electrolyte of lithium-ion battery are investigated through differential scanning calorimetry(DSC) and evolved gas analysis.The lithiated graphite in the presence of electrolyte exhibit three exothermic peaks during DSC test.The reactions between lithiated graphite and LiPF_(6) and ethylene carbonate are found to be responsible for the first two exothermic peaks,while the third exothermic peak is attributed to the reaction between lithiated graphite and binder.In contrast,diethylene carbonate and ethyl methyl carbonate contribute little to the total heat generation of graphite-electrolyte reactions.The reaction mechanism between lithiated graphite and electrolyte,including the major reaction equations and gas products,are summarized.Finally,DSC tests on samples with various amounts of electrolyte are performed to clarify the quantitative relationship between lithiated graphite and electrolyte during the exothermic reactions.2.5 mg of lithiated graphite (Li_(0.8627)C_(6)) can fully react with around 7.2 mg electrolyte,releasing a heat generation of 2491 J g^(-1).The results presented in this study can provide useful guidance for the safety improvement of lithium-ion batteries.
基金supported by the Natural Science Foundation of Hebei Province (B2021507001)the National Natural Science Foundation of China (52106284, 52076121)+2 种基金the Ministry of Science and Technology (2022YFE0207900)the support of the Science and Technology Project of Langfang (2021011017)the Project to Promote Innovation in Doctoral Research at CPPU (BSKY202302)。
文摘Structurally compact battery packs significantly improve the driving range of electric vehicles.Technologies like Cell-to-Pack increase energy density by 15%-20%.However,the safety implications of multiple tightly-packed battery cells still require in-depth research.This paper studies thermal runaway propagation behavior in a Cell-to-Pack system and assesses propagation speed relative to other systems.The investigation includes temperature response,extent of battery damage,pack structure deformation,chemical analysis of debris,and other considerations.Results suggest three typical patterns for the thermal runaway propagation process:ordered,disordered,and synchronous.The synchronous propagation pattern displayed the most severe damage,indicating energy release is the largest under the synchronous pattern.This study identifies battery deformation patterns,chemical characteristics of debris,and other observed factors that can both be applied to identify the cause of thermal runaway during accident investigations and help promote safer designs of large battery packs used in large-scale electric energy storage systems.
基金This work is funded by National Natural Science Foundation of China(Grant No.52006115)Ministry of Science and Technology of China(Grant No.2019YFE0100200)+3 种基金National Natural Science Foundation of China(Grant No.52076121)China National Postdoctoral Program for Innovative Talents(Grant No.BX20190162)China Postdoctoral Science Foundation(Grant No.2019M660631)the Tsinghua University Initiative Scientific Research Program(Grant No.2019Z02UTY06).
文摘Fluorinated electrolytes possess good antioxidant capacity that provides high compatibility to high-voltage cathode and flame retardance;thus,they are considered as a promising solution for advanced lithium-ion batteries carrying both high-energy density and high safety.Moreover,the fluorinated electrolytes are widely used to form stable electrolyte interphase,due to their chemical reactivity with lithiated graphite or lithium.However,the influence of this reactivity on the thermal safety of batteries is seldom discussed.Herein,we demonstrate that the flame-retardant fluorinated electrolytes help to reduce the flammability,while the lithium-ion batteries with flame-retardant fluorinated electrolytes still undergo thermal runaway and disclose their different thermal runaway pathway from that of battery with conventional electrolyte.The reduction in fluorinated components(e.g.,LiPF 6 and fluoroethylene carbonate(FEC))by fully lithiated graphite accounts for a significant heat release during battery thermal runaway.The 13%of total heat is sufficient to trigger the chain reactions during battery thermal runaway.This study deepens the understanding of the thermal runaway mechanism of lithium-ion batteries employing flame-retardant fluorinated electrolytes,providing guidance on the concept of electrolyte design for safer lithium-ion batteries.
基金supported by the Ministry of Science and Technology of China(2019YFE0100200)funded by the National Natural Science Foundation of China(51807108,51877121,52037006)。
文摘The safety monitoring of lithium-ion batteries(LIBs) is of great significance for realizing all-climate and full-lifespan battery management. In-situ measurement of anode potential with implanted reference electrodes(REs) has proven to be effective to monitor and avoid the occurrence of severe side reactions like Li plating to ensure the safe and fast charging. However, the intrinsic measurement errors caused by local blocking effects, which also can be referred to as potential artefacts, are seldom taken into consideration in existing studies, yet they highly dominate the correctness of conclusions inferred from REs. In this study, aiming at exploring the physical origin of the measurement errors and ensure reliable potential monitoring, electrochemical and post-mortem tests are conducted using commercial pouch cells with implanted REs. Corresponding electrochemical model which describes the blocking effects, is established to validate the abnormal absence of lithium plating that predicted by measured anode potentials under various charging rates. Theoretical derivation is further presented to explain the error sources, which can be attributed to increased local liquid potential of the RE position. Most importantly, with the guidance of error analysis, a novel parameter-independent error correction method for RE measurements is proposed for the first time, which is proven to be adequate to estimate the real anode potentials and deduce the critical C-rate of Li plating with extra safety margin. After error correction, the resulting critical C-rates are all within the range of 0.55 ± 0.03 C, which is close to the C-rate of 0.6–0.7 C obtained from experiments. In addition, this error correction method can be performed conveniently with only some simple RE measurements of polarization voltages, totally independent of battery electrochemical and geometric parameters. This study provides highly practical error correction method for RE measurements in real LIBs, substantially facilitating the fast diagnosis and safety evaluation of Li plating during charging of LIBs.
基金supported by the National Key R&D ProgramStrategic Scientific and Technological Innovation Cooperation(2022YFB3803500)the National Key Research and Development Program of China(2019YFA0705700)+1 种基金the National Natural Science Foundation of China(52076121,51904016,and 52004138)the Fundamental Research Funds for the Central Universities。
文摘As the energy density of battery increases rapidly,lithium-ion batteries(LIBs)are facing serious safety issue with thermal runaway,which largely limits the large-scale applications of high-energy-density LIBs.It is generally agreed that the chemical crosstalk between the cathode and anode leads to thermal runaway of LIBs.Herein,a multifunctional high safety electrolyte is designed with synergistic construction of cathode electrolyte interphase and capture of reactive free radicals to limit the intrinsic pathway of thermal runaway.The cathode electrolyte interphase not only resists the gas attack from the anode but suppresses the parasitic side reactions induced by electrolyte.And the function of free radical capture has the ability of reducing heat release from thermal runaway of battery.The dual strategy improves the intrinsic safety of battery prominently that the triggering temperature of thermal runaway is increased by 24.4℃and the maximum temperature is reduced by 177.7℃.Simultaneously,the thermal runaway propagation in module can be self-quenched.Moreover,the electrolyte design balances the trade-off of electrochemical and safety performance of high-energy batteries.The capacity retention of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)|graphite pouch cell has been significantly increased from 53.85%to 97.05%with higher coulombic efficiency of 99.94%at operating voltage extended up to 4.5 V for 200 cycles.Therefore,this work suggests a feasible strategy to mitigate the safety risk of high-energy-density LIBs without sacrificing electrochemical performances.
基金supported by the National Natural Science Foundation of China (52076121, 51977131, and 51877138)the Natural Science Foundation of Shanghai (19ZR1435800)+1 种基金the State Key Lab-oratory of Automotive Safety and Energy under Project No. KF2020the Shanghai Science and Technology Development Fund(19QA1406200)。
文摘Lithium-ion batteries with high-energy density are extensively commercialized in long-range electric vehicles. However, they are poor in thermal stability and pose fire or explosion, which has attracted the global attention. This study describes a new route to mitigate the battery thermal runaway(TR) hazard by poison agents. First, the self-destructive cell is built using the embedded poison layer. Then, the poisoning mechanism and paths are experimentally investigated at the material, electrode, and cell levels. Finally, the proposed route is verified by TR tests. The results show the TR hazard can be significantly reduced in the self-destructive cell based on a new reaction sequence regulation. Specifically, the maximum temperature of the self-destructive cell is more than 300℃ lower than that of the normal cell during TR. The drop in maximum temperature can reduce total heat release and the probability of TR propagation in the battery system, significantly improving battery safety.
基金funding from the research project“Safe-DaBatt”(03EMF0409A)funded by the German Federal Ministry of Digital and Transport(BMDV).
文摘There is an increasing demand for real-time data-driven fault diagnosis of lithium-ion batteries that can predict battery faults at an early stage to avoid safety issues and improve battery reliability.However,such prediction methods require large amounts of data,generally obtained through experiments or during the operation phase,resulting in substantial economic and time efforts.In this context,generating realistic battery pack data that covers all sensor values a battery management system receives,as well as including fault models,is of particular interest and can mitigate the need to perform extensive laboratory testing.This paper focuses on the systematic development of a data generation platform capable of simulating a large scale of battery packs with random battery faults and generating big data for the following battery fault diagnostics.Initially,the electrical,thermal,and aging modeling of a battery pack is performed.After this,four types of faults,namely hard short circuit,soft short circuit,abnormal internal resistance,and abnormal contact resistance,are modeled using equivalent circuit models.To generate realistic data,both cell-to-cell variations and pack-level variations are considered.Variations included are,for example,the manufacturing quality,temperatures,aging processes,road conditions,state of charge,and fault severity.By combining the battery pack models,fault models,and the different variations through Monte Carlo simulations,a large data set representing different packs with varying levels of inconsistencies is generated.
基金supported by the National Key R&D Program of China(No.2021YFB2401900)National Natural Science Foundation of China under No.52177217.
文摘The morphology of plated lithium(MPL)metal on graphite anodes,traditionally described as“moss-like”and“dendrite-like”,exert a substantial negative influence on the performance of lithium-ion batteries(LIBs)by modulating the metal-electrolyte interface and side reaction rates.However,a systematic and quantitative analysis of MPL is lacking,impeding effective evaluation and manipulation of this detrimental issue.In this study,we transition from a qualitative analysis to a quantitative one by conducting a detailed examination of the MPL.Our findings reveal that slender lithium dendrites reduces the lifespan and safety of LIB by increasing the side reaction rates and promoting the formation of dead lithium.To further evaluate the extent of the detrimental effect of MPL,we propose the specific surface area(SSA)as a critical metric,and develop an in situ method integrating expansion force and electrochemical impedance spectroscopy to estimate SSA.Finally,we introduce a pulse current protocol to manipulate hazardous MLP.Phase field model simulations and experiments demonstrate that this protocol significantly enhances the reversibility of plated lithium.This research offers a novel morphological perspective on lithium plating,providing a more detailed fundamental understanding that facilitates effective evaluation and manipulation of plated lithium,thereby enhancing the safety and extending the cycle life of LIBs.
基金This study is supported by the National Key R&D Program-Strategic Scientific and Technological Innovation Cooperation(#2022YFE0207900)the National Natural Science Foundation of China[Grant No.51706117,52076121].
文摘Despite the widespread utilization of Lithium-ion batteries(LIBs),concerns regarding safety during operation persist owing to accidents and potential risks of fires and explosions.To comprehend the thermal dynamics that underlie severe LIB incidents,calorimetry tests have been prevalently employed for over three decades to examine the exothermic/endothermic behavior,reaction kinetics,and thermal interactions among LIB materials.There exists a substantial volume of calorimetry test results on various LIB electrodes,electrolytes,and other components.However,this data showcases low consistency,yielding an unreliable database that obstructs a thorough understanding of LIB thermal behavior.In this research,a comparative analysis of differential scanning calorimetry(DSC)results from materials utilized in the most commercialized LIB systems is conducted.The analysis unveils notable discrepancies in DSC data amassed by different researchers,identifies five predominant causes of data inconsistency,proposes a standardized DSC operational procedure,and generates a set of self-consistent data.Subsequently,an intrinsic safety spectrum is delineated and compared with X-ray diffraction(XRD)outcomes to elucidate the correlation between the crystal lattice structure and the thermal behavior of the material.This work aids in the formation of a comparative DSC database,utilizing the vast but inconsistent literature data.Moreover,it clarifies the linkage between the material structure and thermal behavior,facilitating data-driven thermal analysis of LIBs.
基金supported by the National Key R&D Program-Strategic Scientific and Technological Innovation Cooperation(2022YFE0207900)the National Natural Science Foundation of China(52004138 and 52076121)+1 种基金the National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact(WDZC2022-2)the Beijing Institute of Technology Research Fund Program for Young Scholars(XSQD-202210008)。
文摘With the continuous development of the electrification industry,the development of high-specific batteries has attracted much attention.However,the safety of lithiumion batteries is currently unable to meet the market demand due to poor thermal stability.Solving the thermal issues is crucial to improve battery safety.Ethylene carbonate(EC)not only plays an important interfacial film-forming role,but also poses safety risks in terms of reactivity.In this work,we conducted a series of gradient experiments utilizing different EC amounts and verified the effect of reducing EC on battery performance.A strategy is also proposed to design a new electrolyte.Ethyl methyl carbonate(EMC)is used instead of EC as the main solvent to improve the thermal safety of the battery,while salts and additives are used to dominate the film formation to improve the cycling stability of the battery under high voltages(4.5 V,~90%after 200 cycles).This work paves a new avenue for the development of novel electrolyte systems.
基金Supported by the Ministry of Science and Technology of China (Grant No.2022YFB2404803)the National Natural Science Foundation of China (Grant No.52207241)the International Joint Mission on Climate Change and Carbon Neutrality。
文摘To investigate the effect of different states of charge(SOC)on the thermal runaway(TR)propagation behaviors within lithium-ion-batteries based energy storage modules,an experimental setup was developed to conduct failure propagation tests on battery modules at an SOC of 97%,85%,and 50%.The result indicates that an increase in the SOC of batteries can decrease the TR trigger temperature,making batteries trigger TR earlier and reducing the average failure propagation time between two adjacent cells.In addition,the failure propagation tests reveal that at higher SOCs,the TR reaction becomes more violent,the maximal reaction temperature is also much higher,and the damage to the battery module is severe.Compared to the battery module with 97%SOC,the TR trigger time of the battery module with 50%SOC was postponed by approximately 57.8%.Meanwhile,the average failure propagation time got prolonged by approximately 36.0%.Thus,this study can provide references for the thermal safety design of energy-storage battery modules.
基金This work is supported by the Beijing Natural Science Foundation under the Grant No.3184052the National Natural Science Foundation of China(NSFC)under the Grant No.51807108 and No.U1564205International Science and Technology Cooperation Program of China under contract No.2016YFE0102200.
文摘Lithium-ion(Li-ion)cells degrade after repeated cycling and the cell capacity fades while its resistance increases.Degra-dation of Li-ion cells is caused by a variety of physical and chemical mechanisms and it is strongly influenced by factors including the electrode materials used,the working conditions and the battery temperature.At present,charging voltage curve analysis methods are widely used in studies of battery characteristics and the constant current charging voltage curves can be used to analyze battery aging mechanisms and estimate a battery’s state of health(SOH)via methods such as incremental capacity(IC)analysis.In this paper,a method to fit and analyze the charging voltage curve based on a neural network is proposed and is compared to the existing point counting method and the polynomial curve fitting method.The neuron parameters of the trained neural network model are used to analyze the battery capacity relative to the phase change reactions that occur inside the batteries.This method is suitable for different types of batteries and could be used in battery management systems for online battery modeling,analysis and diagnosis.
基金supported by the Key-Area Research and Development Program of Guangdong Province(2020B0909030001)the National Natural Science Foundation of China(52007099,52076121 and 52177217)+1 种基金China Postdoctoral Science Foundation(2020M680550)support from Young Elite Scientists Sponsorship Program by CAST[No.YESS20220063].
文摘LiFePO_(4)(LFP)lithium-ion batteries have gained widespread use in electric vehicles due to their safety and longevity,but thermal runaway(TR)incidents still have been reported.This paper explores the TR characteristics and modeling of LFP batteries at different states of charge(SOC).Adiabatic tests reveal that TR severity increases with SOC,and five stages are identified based on battery temperature evolution.Reaction kinetics parameters of exothermic reactions in each TR stage are extracted,and TR models for LFP batteries are established.The models accurately simulate TR behaviors at different SOCs,and the simulated TR characteristic temperatures also agree well with the experimental results,with errors of TR characteristic temperatures less than 3%.The prediction errors of TR characteristic temperatures under oven test conditions are also less than 1%.The results provide a comprehensive understanding of TR in LFP batteries,which is useful for battery safety design and optimization.
基金supported by National Natural Science Foundation of China(NSFC)(nos.U20A20310,52176199,and 52076121)sponsored by Program of Shanghai Academic/Technology Research Leader(22XD1423800).
文摘Further applications of electric vehicles(EVs)and energy storage stations are limited because of the thermal sensitivity,volatility,and poor durability of lithium-ion batteries(LIBs),especially given the urgent requirements for all-climate utilization and fast charging.This study comprehensively reviews the thermal characteristics and management of LIBs in an all-temperature area based on the performance,mechanism,and thermal management strategy levels.
