Lithium plating is a detrimental phenomenon in lithium-ion cells that compromises both functionality and safety.This study investigates electro-chemo-mechanical behaviors of lithium plating in lithium iron phosphate p...Lithium plating is a detrimental phenomenon in lithium-ion cells that compromises both functionality and safety.This study investigates electro-chemo-mechanical behaviors of lithium plating in lithium iron phosphate pouch cells under different external pressures.Atomic force microscopy nanoindentation is performed on the graphite electrode to analyze the influence of external pressure on solid-electrolyte interphase(SEI),revealing that the mechanical strength of SEI,indicated by Young's modulus,increases with the presence of external pressure.Then,an improved phase field model for lithium plating is developed by incorporating electrochemical parameterization based on nonequilibrium thermodynamics.The results demonstrate that higher pressure promotes lateral lithium deposition,covering a larger area of SEI.Moreover,electrochemical impedance spectroscopy and thickness measurements of the pouch cells are conducted during overcharge,showing that external pressure suppresses gas generation and thus increases the proportion of lithium deposition among galvanostatic overcharge reactions.By integrating experimental results with numerical simulations,it is demonstrated that moderate pressure mitigates SEI damage during lithium plating,while both insufficient and excessive pressure may exacerbate it.This study offers new insights into optimizing the design and operation of lithium iron phosphate pouch cells under external pressures.展开更多
Lithium plating in working batteries has attracted wide attention in the exploration of safe energy storage. Establishing an effective and rapid early-warning method is strongly considered but quite challenging since ...Lithium plating in working batteries has attracted wide attention in the exploration of safe energy storage. Establishing an effective and rapid early-warning method is strongly considered but quite challenging since lithium plating behavior is determined by diverse factors. In this contribution, we present a non-destructive electrochemical detection method based on transient state analysis and threeelectrode cell configuration. Through dividing the iR drop value by the current density, the as-obtained impedance quantity(R_(i)) can serve as a descriptor to describe the change of electrochemical reaction impedance on the graphite anode. The onset of lithium plating can be identified from the sharp drop of R_(i). Once the dendritic plated lithium occurs, the extra electrochemical reactions at the lithium interfaces leads to growing active area and reduced surface resistance of the anode. We proposed a protocol to operate the batteries under the limited capacity, which renders the cell with 98.2% capacity retention after 1000 cycles without lithium plating. The early-warning method has also been validated in in-situ optical microscopy batteries and practical pouch cells, providing a general but effective method for online lithium plating detection towards safe batteries.展开更多
Fast charging capability of lithium-ion batteries is in urgent need for widespread economic success of electric vehicles. However, the application of the fast charging technology often leads to the inevitable lithium ...Fast charging capability of lithium-ion batteries is in urgent need for widespread economic success of electric vehicles. However, the application of the fast charging technology often leads to the inevitable lithium plating on the graphite anode, which is one of the main culprits that endanger battery safety and shorten battery lifespan. The in-depth understanding of the initiation of lithium metal nucleation and the following plating behavior is a key to the development of fast charging cells. Herein, we investigate the overlooked effect of the non-uniform distribution of electrolyte on lithium plating during fast charging. Prior lithium plating occurs on the saturated lithium-graphite compounds in the anode region with sufficient electrolyte since the lithium-ion transport is blocked in the anode region lacking electrolyte. The uniform distribution of electrolyte is crucial for the construction of safe lithium-ion batteries especially in fast charging scenarios.展开更多
Fast charging is restricted primarily by the risk of lithium(Li)plating,a side reaction that can lead to the rapid capacity decay and dendrite-induced thermal runaway of lithium-ion batteries(LIBs).Investigation on th...Fast charging is restricted primarily by the risk of lithium(Li)plating,a side reaction that can lead to the rapid capacity decay and dendrite-induced thermal runaway of lithium-ion batteries(LIBs).Investigation on the intrinsic mechanism and the position of Li plating is crucial to improving the fast rechargeability and safety of LIBs.Herein,we investigate the Li plating behavior in porous electrodes under the restricted transport of Li^(+).Based on the theoretical model,it can be concluded that the Li plating on the anodeseparator interface(ASI)is thermodynamically feasible and kinetically advantageous.Meanwhile,the prior deposition of metal Li on the ASI rather than the anode-current collector interface(ACI)is verified experimentally.In order to facilitate the transfer of Li^(+)among the electrode and improve the utilization of active materials without Li plating,a bilayer asymmetric anode composed of graphite and hard carbon(GH)is proposed.Experimental and simulation results suggest that the GH hybrid electrode homogenizes the lithiated-rate throughout the electrode and outperforms the pure graphite electrode in terms of the rate performance and inhibition of Li plating.This work provides new insights into the behavior of Li plating and the rational design of electrode structure.展开更多
This vertically self‐pillared(VSP)structure extends the application range of traditional porous materials with facile mass/ion transport and enhanced reaction kinetics.Here,we prepare a single crystal metal‐organic ...This vertically self‐pillared(VSP)structure extends the application range of traditional porous materials with facile mass/ion transport and enhanced reaction kinetics.Here,we prepare a single crystal metal‐organic framework(MOF),employing the ZIF‐67 structure as a proof of concept,which is constructed by vertically self‐pillared nanosheets(VSP‐MOF).We further converted VSP‐MOF into VSP‐cobalt sulfide(VSP‐CoS2)through a sulfidation process.Catalysis plays an important role in almost all battery technologies;for metallic batteries,lithium anodes exhibit a high theoretical specific capacity,low density,and low redox potential.However,during the half‐cell reaction(Li++e=Li),uncontrolled dendritic Li penetrates the separator and solid electrolyte interphase layer.When employed as a composite scaffold for lithium metal deposition,there are many advantage to using this framework:1)the VSP‐CoS2 substrate provides a high specific surface area to dissipate the ion flux and mass transfer and acts as a pre‐catalyst,2)the catalytic Co center favors the charge transfer process and preferentially binds the Li+with the enhanced electrical fields,and 3)the VSP structure guides the metallic propagation along the nanosheet 2D orientation without the protrusive dendrites.All these features enable the VSP structure in metallic batteries with encouraging performances.展开更多
Lithium plating has been identified as the main form of failure in fast charging,so it is imperative to develop effective methods for detecting lithium plating.Experimental results validated the effectiveness of lithi...Lithium plating has been identified as the main form of failure in fast charging,so it is imperative to develop effective methods for detecting lithium plating.Experimental results validated the effectiveness of lithium plating detection via expansion force measurement.While multi-stage constant current(MCC)charging is a common form of fast charging,experimental investigations of lithium plating under MCC charging remain scarce,particularly lacking models to describe the battery expansion force changes during the lithium plating process under MCC conditions.The expansion of batteries during charging is caused by factors such as intercalation reactions,thermal expansion,and lithium plating.Through the establishment of the coupling model,the expansion displacement of the battery is calculated.The thermal expansion coefficient and equivalent stiffness of the battery are obtained through experiments,which are used to calculate the battery expansion force.Additionally,the battery overpotential is calculated through the model to determine the impact of lithium plating on the expansion force.The model investigates the effects of lithium plating on battery expansion force under different C-rates during constant current and MCC charging processes,achieving semi-quantitative prediction of battery expansion force under MCC charging and providing model-based optimization directions for MCC charging strategies.This work provides valuable insights for battery modeling and charging strategy optimization in terms of expansion force modeling under multi-stage constant current charging.展开更多
Lithium-plating-type defects in lithium-ion batteries pose severe safety risks due to their potential to trigger thermal runaway.To prevent defective batteries from entering the market,developing in-line detection met...Lithium-plating-type defects in lithium-ion batteries pose severe safety risks due to their potential to trigger thermal runaway.To prevent defective batteries from entering the market,developing in-line detection methods during manufacturing is critical yet challenging.This study introduces a deep learning-based method for detecting lithium-plating-type defects using formation and capacity grading data,enabling accurate identification of defective batteries without additional equipment.First,lithiumplating-type defect batteries with various types and area ratios are fabricated.Formation and capacity grading data from 154 batteries(48 defective,106 normal)are collected to construct a dataset.Subsequently,a dual-task deep learning model is then developed,where the reconstruction task learns latent representations from the features,while the classification task identifies the defective batteries.Shapley value analysis further quantifies feature importance,revealing that defective batteries exhibit reduced coulombic efficiency(attributed to irreversible lithium loss)and elevated open-circuit voltage/K-values(linked to self-equalization effects).These findings align with the electrochemical mechanisms of lithium plating,enhancing the model's interpretability.Validated on statistically robust samples shows that the framework achieves a recall of 97.14%for defective batteries and an overall accuracy of 97.42%.This deep learning-driven solution provides a scalable and cost-effective quality control strategy for battery manufacturing.展开更多
Lithium-ion capacitors(LICs)offer higher power density and longer cycle life compared to lithium-ion batteries,and greater energy density than supercapacitors,making them ideal for applications requiring both high ene...Lithium-ion capacitors(LICs)offer higher power density and longer cycle life compared to lithium-ion batteries,and greater energy density than supercapacitors,making them ideal for applications requiring both high energy and power density.However,during high-rate charging,LIC anodes may suffer from lithium plating,a critical issue that remains unaddressed.To date,no direct analytical technique exists to study lithium plating behavior on LIC anodes.This study is the first to employ a 3-electrode pouch-type LICs,using differential analysis of the anode potential rather than the traditional terminal voltage approach,to accurately detect the charging rates at which lithium plating begins.We employed differential charging voltage(DCV),Coulombic efficiency(CE),and voltage relaxation profile(VRP)methods to comprehensively analyze lithium plating behavior.The feasibility of indirectly detecting lithium plating was validated by applying the CE and VRP methods to high-capacity 1,100 F LICs.The study found that lithium plating in LICs begins at a charging current of 20 C.The lithium deposited at currents below 50 C is reversible,while at currents above 50 C,irreversible dead lithium is formed.Furthermore,the study identified two reverse reactions following lithium deposition on the anode:lithium stripping and lithium intercalation.For soft carbon anodes,the potential difference between lithium stripping and intercalation was approximately 20 mV under relaxation conditions,and about 45 mV under constant voltage conditions.This research provides critical theoretical insights and practical guidance for optimizing LIC charging strategies.展开更多
Lithium plating in lithium-ion batteries(LIBs)is one of the main causes of safety accidents in electric vehicles(EVs).The study of intelligent machine learning-based lithium plating detection and warning algorithms fo...Lithium plating in lithium-ion batteries(LIBs)is one of the main causes of safety accidents in electric vehicles(EVs).The study of intelligent machine learning-based lithium plating detection and warning algorithms for LIBs is of great importance.Therefore,this paper proposes an intelligent lithium plating detection and early warning method for LIBs based on the random forest model.This method can accurately detect lithium plating during the charging process of LIBs,and play an early warning role according to the detection results.First,pulse charging experiments of LIBs,including normal and lithium plating charging tests,were completed and validated using in situ characterization methods.Second,the normalized internal resistance from the pulse charging test is used to detect lithium plating in LIBs.Third,a lithium plating feature extraction method is proposed to address the lack of useful lithium plating information for LIBs during the charging process.Finally,the Random Forest machine learning technique is used to classify and predict the lithium plating of LIBs.The model validation results show that the detection accuracy of lithium plating is greater than 97.2%.This is of significance for the study of intelligent lithium plating detection algorithms for LIBs.展开更多
Lithium plating directly affects the fast-charging ability and safety of electric vehicles.However,existing lithium plating detection methods cannot meet the industry's needs for timeliness,quantification,and robu...Lithium plating directly affects the fast-charging ability and safety of electric vehicles.However,existing lithium plating detection methods cannot meet the industry's needs for timeliness,quantification,and robustness,which seriously restricts the development of electric vehicles and emission reduction.This article provides suggestions for the future development of lithium plating detection methods in different periods of time to support the revolution of the next-generation electric vehicle batteries.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
Here we report an interesting phenomenon that lithium plating from pre-cycling of Li-ion cells at low temperature could reduce degradation and extend cycle life at high temperature.This study confirmed the phenomenon ...Here we report an interesting phenomenon that lithium plating from pre-cycling of Li-ion cells at low temperature could reduce degradation and extend cycle life at high temperature.This study confirmed the phenomenon in both single-layer cells and multi-layer cells.It revealed that compression of the multi-layer cells must be maintained during cycling for the phenomenon to be observed.Without compression,lowtemperature pre-cycling would accelerate high-temperature degradation of the multi-layer cells.This finding helped to clarify the contradictions in previous studies on the effects of low-temperature pre-cycling.A comparison between low-temperature pre-cycling with 1C charging and 0.2C charging confirmed that lithium plating from low-temperature pre-cycling is necessary for the observed benefits.Furthermore,post-mortem analysis of single-layer cells showed a thick deposition layer on the anode of pre-cycled cells,which could be attributed to reactions from lithium plating and the electrolyte.展开更多
The degradation of Lithium-ion batteries(LIBs)during cycling is particularly exacerbated at low temperatures,which has a significant impact on the longevity of electric vehicles,energy storage systems,and consumer ele...The degradation of Lithium-ion batteries(LIBs)during cycling is particularly exacerbated at low temperatures,which has a significant impact on the longevity of electric vehicles,energy storage systems,and consumer electronics.A comprehensive understanding of the low-temperature aging mechanisms throughout the whole life cycle of LIBs is crucial.However,existing research is limited,which typically focuses on capacity degradation to 80%.To fill this gap,this paper conducts low-temperature cyclic aging tests at three different charging rates.The investigation employs differential voltage analysis,the distribution of relaxation times technique,and disassembly characterization to explore both thermodynamic degradation and kinetic degradation,alongside a correlation analysis of the factors influencing these degradation processes.The results reveal two distinct knee points in the capacity decline of LIBs during the whole life cycle,in contrast to prior studies identifying only one.Before the first knee point,the thickening of the SEI film dominates capacity loss,with higher charging rates accelerating the process.After the first knee point,the main degradation mechanisms shift to lithium plating and the fracture of the positive electrode active particles.These two aging factors become more pronounced with ongoing cycling,culminating in a second knee point in capacity decline.Notably,a novel finding demonstrates that after the second knee point,capacity degradation progresses faster at lower charging rates compared to medium rates.The reason is the fracture of graphite particles also becomes a critical contributor to the severe capacity degradation at lower charging rates.These insights will guide the designs of next-generation low-temperature LIBs and low-temperature battery management systems.展开更多
Understanding the thermal safety evolution of lithium-ion batteries during high-temperature usage conditions bears significant implications for enhancing the safety management of aging batteries.This work investigates...Understanding the thermal safety evolution of lithium-ion batteries during high-temperature usage conditions bears significant implications for enhancing the safety management of aging batteries.This work investigates the thermal safety evolution mechanism of lithium-ion batteries during high-temperature aging.Similarities arise in the thermal safety evolution and degradation mechanisms for lithium-ion batteries undergoing cyclic aging and calendar aging.Employing multi-angle characterization analysis,the intricate mechanism governing the thermal safety evolution of lithium-ion batteries during high-temperature aging is clarified.Specifically,lithium plating serves as the pivotal factor contributing to the reduction in the self-heating initial temperature.Additionally,the crystal structure of the cathode induced by the dissolution of transition metals and the reductive gas generated during aging attacking the crystal structure of the cathode lead to a decrease in thermal runaway triggering temperature.Furthermore,the loss of active materials and active lithium during aging contributes to a decline in both the maximum temperature and the maximum temperature rise rate,ultimately indicating a decrease in the thermal hazards of aging batteries.展开更多
The lithium(Li) metal anode is an integral component in an emerging high-energy-density rechargeable battery.A composite Li anode with a three-dimensional(3 D) host exhibits unique advantages in suppressing Li dendrit...The lithium(Li) metal anode is an integral component in an emerging high-energy-density rechargeable battery.A composite Li anode with a three-dimensional(3 D) host exhibits unique advantages in suppressing Li dendrites and maintaining dimensional stability.However,the fundamental understanding and regulation of solid electrolyte interphase(SEI),which directly dictates the behavior of Li plating/stripping,are rarely researched in composite Li metal anodes.Herein,the interaction between a polar polymer host and solvent molecules was proposed as an emerging but effective strategy to enable a stable SEI and a uniform Li deposition in a working battery.Fluoroethylene carbonate molecules in electrolytes are enriched in the vicinity of a polar polyacrylonitrile(PAN) host due to a strong dipole-dipole interaction,resulting in a LiF-rich SEI on Li metal to improve the uniformity of Li deposition.A composite Li anode with a PAN host delivers 145 cycles compared with 90 cycles when a non-polar host is employed.Moreover,60 cycles are demonstrated in a 1:0 Ah pouch cell without external pressure.This work provides a fresh guidance for designing practical composite Li anodes by unraveling the vital role of the synergy between a 3 D host and solvent molecules for regulating a robust SEI.展开更多
The interfacial stability of lithium metal anodes dictated by solid electrolyte interphase(SEI) is essential for long-cycling high-energy-density lithium–sulfur batteries. Nevertheless, critical components of SEI for...The interfacial stability of lithium metal anodes dictated by solid electrolyte interphase(SEI) is essential for long-cycling high-energy-density lithium–sulfur batteries. Nevertheless, critical components of SEI for interfacial stabilization are particularly indistinct. Herein, the effect of various sulfur-containing components in SEI for stabilizing lithium metal anodes is disclosed in lithium–sulfur batteries. High-valence sulfur-containing species(Li_(2)SO_(3) and Li_(2)SO_(4)) in SEI are conducive to uniform lithium deposition and stabilizing lithium metal anodes. In contrast, low-valence sulfur-containing species(Li_(2)S_(3) and Li_(2)S_(4)) in SEI result in aggressive lithium dendrites and dead lithium. This work identifies the role of sulfurcontaining components in SEI for stabilizing lithium metal anodes and provides rational design principles of SEI for protecting lithium metal anodes in practical lithium–sulfur batteries.展开更多
The application of Li metal anodes in rechargeable batteries is impeded by safety issues arising from the severe volume changes and formation of dendritic Li deposits.Three‐dimensional hollow carbon is receiving incr...The application of Li metal anodes in rechargeable batteries is impeded by safety issues arising from the severe volume changes and formation of dendritic Li deposits.Three‐dimensional hollow carbon is receiving increasing attention as a host material capable of accommodating Li metal inside its cavity;however,uncontrollable and nonuniform deposition of Li remains a challenge.In this study,we synthesize metal–organic framework‐derived carbon microcapsules with heteroatom clusters(Zn and Ag)on the capsule walls and it is demonstrated that Ag‐assisted nucleation of Li metal alters the outward‐to‐inward growth in the microcapsule host.Zn‐incorporated microcapsules are prepared via chemical etching of zeolitic imidazole framework‐8 polyhedra and are subsequently decorated with Ag by a galvanic displacement reaction between Ag^(+) and metallic Zn.Galvanically introduced Ag significantly reduces the energy barrier and increases the reaction rate for Li nucleation in the microcapsule host upon Li plating.Through combined electrochemical,microstructural,and computational studies,we verify the beneficial role of Ag‐assisted Li nucleation in facilitating inward growth inside the cavity of the microcapsule host and,in turn,enhancing electrochemical performance.This study provides new insights into the design of reversible host materials for practical Li metal batteries.展开更多
The accurate representation of lithium plating and aging phenomena has posed a persistent challenge within the battery research community.Empirical evidence underscores the pivotal role of cell structure in influencin...The accurate representation of lithium plating and aging phenomena has posed a persistent challenge within the battery research community.Empirical evidence underscores the pivotal role of cell structure in influencing aging behaviors and lithium plating within lithium-ion batteries(LIBs).Available lithium-ion plating models often falter in detailed description when integrating the structural intricacies.To address this challenge,this study proposes an innovative hierarchical model that intricately incorporates the layered rolling structure in cells.Notably,our model demonstrates a remarkable capacity to predict the non-uniform distribution of current density and overpotential along the rolling direction of LIBs.Subsequently,we delve into an insightful exploration of the structural factors that influence lithium plating behavior,leveraging the foundation laid by our established model.Furthermore,we easily update the hierarchical model by considering aging factors.This aging model effectively anticipates capacity fatigue and lithium plating tendencies across individual layers of LIBs,all while maintaining computational efficiency.In light of our findings,this model yields novel perspectives on capacity fatigue dynamics and local lithium plating behaviors,offering a substantial advancement compared to existing models.This research paves the way for more efficient and tailored LIB design and operation,with broad implications for energy storage technologies.展开更多
The low-temperature performance of Li-ion batteries(LIBs) has important impacts on their commercial applications. Besides the metallic lithium deposition, which is regarded as one of the main failure mechanisms of the...The low-temperature performance of Li-ion batteries(LIBs) has important impacts on their commercial applications. Besides the metallic lithium deposition, which is regarded as one of the main failure mechanisms of the LIBs at low temperatures, the synergistic effects originating from the cathode, anode, electrolyte, and separators to the batteries are still not clear. Here, the 21700-type cylindrical batteries were evaluated at a wide range of temperatures to investigate the failure mechanism of batteries. Voltage relaxation, and the post-mortem analysis combined with the electrochemical tests, unravel that the capacity degradation of batteries at low temperature is related to the lithium plating at graphite anodes,the formation of unsatisfied solid deposited/decomposed electrolyte mixture phase on the anode, the precipitation of solvent in the electrolytes and the block of separator pores, and the uneven dissolved transition metal-ions from the cathode. We hope this finding may open up a new avenue to alleviate the capacity degradation of advanced LIBs at low temperatures and shed light on the development of outstanding low-temperature LIBs via simultaneous optimization of all the components including electrodes, electrolytes and separators.展开更多
The performance and lifespan of Li-ion batteries used in electric vehicles are influenced by operating and environmental conditions.An understanding of the mechanisms leading to performance degradation and capacity fa...The performance and lifespan of Li-ion batteries used in electric vehicles are influenced by operating and environmental conditions.An understanding of the mechanisms leading to performance degradation and capacity fading can aid in the design of better battery systems.In the present study,numerical models are developed to estimate the capacity fading,battery performance,and residual life.Furthermore,key associated parameters are identified as state of charge,charging protocols,and temperature.Later on,a deep machine learning(DML)model consisting of one input,four hidden,and one output layer is developed to estimate the residual life of a battery system.The five input parameters considered include voltage,current,temperature,number of cycles,and time,apart from residual life as the output parameter.The proposed DML model consists of five dense layers and three dropout layers with 2889 trainable parameters in total,with higher neuron counts in initial layers to process diverse inputs and fewer neurons in later layers to ensure compact feature representation as well as to make better and faster predictions.Results from the numerical and DML models are compared to the reported experimental results,where good agreement is observed.Thus,the developed model is tested on Lithium based Nickel Manganese Cobalt Oxide and Nickel Cobalt Aluminum Oxide batteries,for which parametric studies are performed to investigate the influence of the operating temperature,rate of charge/discharge,and pulse charging on the battery life.Therefore,the technologies proposed in this study can contribute to the development of intelligent battery management systems,enabling enhanced performance,and hence prolonged life of battery systems.展开更多
基金supported by the National Key R&D Program of China(Grant No.2023YFB2503800)。
文摘Lithium plating is a detrimental phenomenon in lithium-ion cells that compromises both functionality and safety.This study investigates electro-chemo-mechanical behaviors of lithium plating in lithium iron phosphate pouch cells under different external pressures.Atomic force microscopy nanoindentation is performed on the graphite electrode to analyze the influence of external pressure on solid-electrolyte interphase(SEI),revealing that the mechanical strength of SEI,indicated by Young's modulus,increases with the presence of external pressure.Then,an improved phase field model for lithium plating is developed by incorporating electrochemical parameterization based on nonequilibrium thermodynamics.The results demonstrate that higher pressure promotes lateral lithium deposition,covering a larger area of SEI.Moreover,electrochemical impedance spectroscopy and thickness measurements of the pouch cells are conducted during overcharge,showing that external pressure suppresses gas generation and thus increases the proportion of lithium deposition among galvanostatic overcharge reactions.By integrating experimental results with numerical simulations,it is demonstrated that moderate pressure mitigates SEI damage during lithium plating,while both insufficient and excessive pressure may exacerbate it.This study offers new insights into optimizing the design and operation of lithium iron phosphate pouch cells under external pressures.
基金supported by the National Natural Science Foundation of China(21808124,22075029)by Beijing Natural Science Foundation(JQ20004)+2 种基金by Scientific and Technological Key Project of Shanxi Province(20191102003)the Seed Fund of Shanxi Research Institute for Clean Energy(SXKYJF015)the Shuimu Tsinghua Scholar Program,and Tsinghua University Initiative Scientific Research Program。
文摘Lithium plating in working batteries has attracted wide attention in the exploration of safe energy storage. Establishing an effective and rapid early-warning method is strongly considered but quite challenging since lithium plating behavior is determined by diverse factors. In this contribution, we present a non-destructive electrochemical detection method based on transient state analysis and threeelectrode cell configuration. Through dividing the iR drop value by the current density, the as-obtained impedance quantity(R_(i)) can serve as a descriptor to describe the change of electrochemical reaction impedance on the graphite anode. The onset of lithium plating can be identified from the sharp drop of R_(i). Once the dendritic plated lithium occurs, the extra electrochemical reactions at the lithium interfaces leads to growing active area and reduced surface resistance of the anode. We proposed a protocol to operate the batteries under the limited capacity, which renders the cell with 98.2% capacity retention after 1000 cycles without lithium plating. The early-warning method has also been validated in in-situ optical microscopy batteries and practical pouch cells, providing a general but effective method for online lithium plating detection towards safe batteries.
基金supported by the Beijing Natural Science Foundation (JQ20004)the National Key Research and Development Program (2021YFB2400300)+1 种基金the National Natural Science Foundation of China (22109083)the Scientific and Technological Key Project of Shanxi Province (20191102003)。
文摘Fast charging capability of lithium-ion batteries is in urgent need for widespread economic success of electric vehicles. However, the application of the fast charging technology often leads to the inevitable lithium plating on the graphite anode, which is one of the main culprits that endanger battery safety and shorten battery lifespan. The in-depth understanding of the initiation of lithium metal nucleation and the following plating behavior is a key to the development of fast charging cells. Herein, we investigate the overlooked effect of the non-uniform distribution of electrolyte on lithium plating during fast charging. Prior lithium plating occurs on the saturated lithium-graphite compounds in the anode region with sufficient electrolyte since the lithium-ion transport is blocked in the anode region lacking electrolyte. The uniform distribution of electrolyte is crucial for the construction of safe lithium-ion batteries especially in fast charging scenarios.
基金supported by the National Natural Scientific Foundation of China (22109083,22379014)Beijing Natural Science Foundation (L233004)。
文摘Fast charging is restricted primarily by the risk of lithium(Li)plating,a side reaction that can lead to the rapid capacity decay and dendrite-induced thermal runaway of lithium-ion batteries(LIBs).Investigation on the intrinsic mechanism and the position of Li plating is crucial to improving the fast rechargeability and safety of LIBs.Herein,we investigate the Li plating behavior in porous electrodes under the restricted transport of Li^(+).Based on the theoretical model,it can be concluded that the Li plating on the anodeseparator interface(ASI)is thermodynamically feasible and kinetically advantageous.Meanwhile,the prior deposition of metal Li on the ASI rather than the anode-current collector interface(ACI)is verified experimentally.In order to facilitate the transfer of Li^(+)among the electrode and improve the utilization of active materials without Li plating,a bilayer asymmetric anode composed of graphite and hard carbon(GH)is proposed.Experimental and simulation results suggest that the GH hybrid electrode homogenizes the lithiated-rate throughout the electrode and outperforms the pure graphite electrode in terms of the rate performance and inhibition of Li plating.This work provides new insights into the behavior of Li plating and the rational design of electrode structure.
文摘This vertically self‐pillared(VSP)structure extends the application range of traditional porous materials with facile mass/ion transport and enhanced reaction kinetics.Here,we prepare a single crystal metal‐organic framework(MOF),employing the ZIF‐67 structure as a proof of concept,which is constructed by vertically self‐pillared nanosheets(VSP‐MOF).We further converted VSP‐MOF into VSP‐cobalt sulfide(VSP‐CoS2)through a sulfidation process.Catalysis plays an important role in almost all battery technologies;for metallic batteries,lithium anodes exhibit a high theoretical specific capacity,low density,and low redox potential.However,during the half‐cell reaction(Li++e=Li),uncontrolled dendritic Li penetrates the separator and solid electrolyte interphase layer.When employed as a composite scaffold for lithium metal deposition,there are many advantage to using this framework:1)the VSP‐CoS2 substrate provides a high specific surface area to dissipate the ion flux and mass transfer and acts as a pre‐catalyst,2)the catalytic Co center favors the charge transfer process and preferentially binds the Li+with the enhanced electrical fields,and 3)the VSP structure guides the metallic propagation along the nanosheet 2D orientation without the protrusive dendrites.All these features enable the VSP structure in metallic batteries with encouraging performances.
基金financially supported by the National Natural Science Foundation of China(No.52207242).
文摘Lithium plating has been identified as the main form of failure in fast charging,so it is imperative to develop effective methods for detecting lithium plating.Experimental results validated the effectiveness of lithium plating detection via expansion force measurement.While multi-stage constant current(MCC)charging is a common form of fast charging,experimental investigations of lithium plating under MCC charging remain scarce,particularly lacking models to describe the battery expansion force changes during the lithium plating process under MCC conditions.The expansion of batteries during charging is caused by factors such as intercalation reactions,thermal expansion,and lithium plating.Through the establishment of the coupling model,the expansion displacement of the battery is calculated.The thermal expansion coefficient and equivalent stiffness of the battery are obtained through experiments,which are used to calculate the battery expansion force.Additionally,the battery overpotential is calculated through the model to determine the impact of lithium plating on the expansion force.The model investigates the effects of lithium plating on battery expansion force under different C-rates during constant current and MCC charging processes,achieving semi-quantitative prediction of battery expansion force under MCC charging and providing model-based optimization directions for MCC charging strategies.This work provides valuable insights for battery modeling and charging strategy optimization in terms of expansion force modeling under multi-stage constant current charging.
基金supported by the National Natural Science Foundation of China(NSFC,52277223 and 51977131)the Shanghai Pujiang Programme(23PJD062)。
文摘Lithium-plating-type defects in lithium-ion batteries pose severe safety risks due to their potential to trigger thermal runaway.To prevent defective batteries from entering the market,developing in-line detection methods during manufacturing is critical yet challenging.This study introduces a deep learning-based method for detecting lithium-plating-type defects using formation and capacity grading data,enabling accurate identification of defective batteries without additional equipment.First,lithiumplating-type defect batteries with various types and area ratios are fabricated.Formation and capacity grading data from 154 batteries(48 defective,106 normal)are collected to construct a dataset.Subsequently,a dual-task deep learning model is then developed,where the reconstruction task learns latent representations from the features,while the classification task identifies the defective batteries.Shapley value analysis further quantifies feature importance,revealing that defective batteries exhibit reduced coulombic efficiency(attributed to irreversible lithium loss)and elevated open-circuit voltage/K-values(linked to self-equalization effects).These findings align with the electrochemical mechanisms of lithium plating,enhancing the model's interpretability.Validated on statistically robust samples shows that the framework achieves a recall of 97.14%for defective batteries and an overall accuracy of 97.42%.This deep learning-driven solution provides a scalable and cost-effective quality control strategy for battery manufacturing.
基金supported by the National Natural Science Foundation of China(Nos.52077207,52377218,52107234 and 52207250)the Youth Innovation Promotion Association,CAS(No.Y2021052).
文摘Lithium-ion capacitors(LICs)offer higher power density and longer cycle life compared to lithium-ion batteries,and greater energy density than supercapacitors,making them ideal for applications requiring both high energy and power density.However,during high-rate charging,LIC anodes may suffer from lithium plating,a critical issue that remains unaddressed.To date,no direct analytical technique exists to study lithium plating behavior on LIC anodes.This study is the first to employ a 3-electrode pouch-type LICs,using differential analysis of the anode potential rather than the traditional terminal voltage approach,to accurately detect the charging rates at which lithium plating begins.We employed differential charging voltage(DCV),Coulombic efficiency(CE),and voltage relaxation profile(VRP)methods to comprehensively analyze lithium plating behavior.The feasibility of indirectly detecting lithium plating was validated by applying the CE and VRP methods to high-capacity 1,100 F LICs.The study found that lithium plating in LICs begins at a charging current of 20 C.The lithium deposited at currents below 50 C is reversible,while at currents above 50 C,irreversible dead lithium is formed.Furthermore,the study identified two reverse reactions following lithium deposition on the anode:lithium stripping and lithium intercalation.For soft carbon anodes,the potential difference between lithium stripping and intercalation was approximately 20 mV under relaxation conditions,and about 45 mV under constant voltage conditions.This research provides critical theoretical insights and practical guidance for optimizing LIC charging strategies.
基金supported by National Natural Science Foundation of China(NSFC)under the Grant number of 52477216Natural Science Foundation of Shanghai under the Grant number of 23ZR1444600in part by the National Natural Science Foundation of China(NSFC)under the Grant number of 52277222.
文摘Lithium plating in lithium-ion batteries(LIBs)is one of the main causes of safety accidents in electric vehicles(EVs).The study of intelligent machine learning-based lithium plating detection and warning algorithms for LIBs is of great importance.Therefore,this paper proposes an intelligent lithium plating detection and early warning method for LIBs based on the random forest model.This method can accurately detect lithium plating during the charging process of LIBs,and play an early warning role according to the detection results.First,pulse charging experiments of LIBs,including normal and lithium plating charging tests,were completed and validated using in situ characterization methods.Second,the normalized internal resistance from the pulse charging test is used to detect lithium plating in LIBs.Third,a lithium plating feature extraction method is proposed to address the lack of useful lithium plating information for LIBs during the charging process.Finally,the Random Forest machine learning technique is used to classify and predict the lithium plating of LIBs.The model validation results show that the detection accuracy of lithium plating is greater than 97.2%.This is of significance for the study of intelligent lithium plating detection algorithms for LIBs.
基金supported by the National Key R&D Program of China(Grant No.2024YFB2505003).
文摘Lithium plating directly affects the fast-charging ability and safety of electric vehicles.However,existing lithium plating detection methods cannot meet the industry's needs for timeliness,quantification,and robustness,which seriously restricts the development of electric vehicles and emission reduction.This article provides suggestions for the future development of lithium plating detection methods in different periods of time to support the revolution of the next-generation electric vehicle batteries.
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supported by the startup funding of G.Z.from The University of Alabama in Huntsville(UAH).
文摘Here we report an interesting phenomenon that lithium plating from pre-cycling of Li-ion cells at low temperature could reduce degradation and extend cycle life at high temperature.This study confirmed the phenomenon in both single-layer cells and multi-layer cells.It revealed that compression of the multi-layer cells must be maintained during cycling for the phenomenon to be observed.Without compression,lowtemperature pre-cycling would accelerate high-temperature degradation of the multi-layer cells.This finding helped to clarify the contradictions in previous studies on the effects of low-temperature pre-cycling.A comparison between low-temperature pre-cycling with 1C charging and 0.2C charging confirmed that lithium plating from low-temperature pre-cycling is necessary for the observed benefits.Furthermore,post-mortem analysis of single-layer cells showed a thick deposition layer on the anode of pre-cycled cells,which could be attributed to reactions from lithium plating and the electrolyte.
基金financially supported by the National Natural Science Foundation of China(NSFC,Grant number U20A20310)the Program of Shanghai Academic/Technology Research Leader(Grant number 22XD1423800)。
文摘The degradation of Lithium-ion batteries(LIBs)during cycling is particularly exacerbated at low temperatures,which has a significant impact on the longevity of electric vehicles,energy storage systems,and consumer electronics.A comprehensive understanding of the low-temperature aging mechanisms throughout the whole life cycle of LIBs is crucial.However,existing research is limited,which typically focuses on capacity degradation to 80%.To fill this gap,this paper conducts low-temperature cyclic aging tests at three different charging rates.The investigation employs differential voltage analysis,the distribution of relaxation times technique,and disassembly characterization to explore both thermodynamic degradation and kinetic degradation,alongside a correlation analysis of the factors influencing these degradation processes.The results reveal two distinct knee points in the capacity decline of LIBs during the whole life cycle,in contrast to prior studies identifying only one.Before the first knee point,the thickening of the SEI film dominates capacity loss,with higher charging rates accelerating the process.After the first knee point,the main degradation mechanisms shift to lithium plating and the fracture of the positive electrode active particles.These two aging factors become more pronounced with ongoing cycling,culminating in a second knee point in capacity decline.Notably,a novel finding demonstrates that after the second knee point,capacity degradation progresses faster at lower charging rates compared to medium rates.The reason is the fracture of graphite particles also becomes a critical contributor to the severe capacity degradation at lower charging rates.These insights will guide the designs of next-generation low-temperature LIBs and low-temperature battery management systems.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.52176199,and U20A20310)supported by the Program of Shanghai Academic/Technology Research Leader(22XD1423800)。
文摘Understanding the thermal safety evolution of lithium-ion batteries during high-temperature usage conditions bears significant implications for enhancing the safety management of aging batteries.This work investigates the thermal safety evolution mechanism of lithium-ion batteries during high-temperature aging.Similarities arise in the thermal safety evolution and degradation mechanisms for lithium-ion batteries undergoing cyclic aging and calendar aging.Employing multi-angle characterization analysis,the intricate mechanism governing the thermal safety evolution of lithium-ion batteries during high-temperature aging is clarified.Specifically,lithium plating serves as the pivotal factor contributing to the reduction in the self-heating initial temperature.Additionally,the crystal structure of the cathode induced by the dissolution of transition metals and the reductive gas generated during aging attacking the crystal structure of the cathode lead to a decrease in thermal runaway triggering temperature.Furthermore,the loss of active materials and active lithium during aging contributes to a decline in both the maximum temperature and the maximum temperature rise rate,ultimately indicating a decrease in the thermal hazards of aging batteries.
基金supported by the National Natural Science Foundation of China (21825501 and U1932220)the National Key Research and Development Program (2016YFA0202500)+2 种基金the Seed Fund of Shanxi Research Institute for Clean Energy (SXKYJF015)the Scientific and technological Key Project of Shanxi Province (20191102003)the Tsinghua University Initiative Scientific Research Program.
文摘The lithium(Li) metal anode is an integral component in an emerging high-energy-density rechargeable battery.A composite Li anode with a three-dimensional(3 D) host exhibits unique advantages in suppressing Li dendrites and maintaining dimensional stability.However,the fundamental understanding and regulation of solid electrolyte interphase(SEI),which directly dictates the behavior of Li plating/stripping,are rarely researched in composite Li metal anodes.Herein,the interaction between a polar polymer host and solvent molecules was proposed as an emerging but effective strategy to enable a stable SEI and a uniform Li deposition in a working battery.Fluoroethylene carbonate molecules in electrolytes are enriched in the vicinity of a polar polyacrylonitrile(PAN) host due to a strong dipole-dipole interaction,resulting in a LiF-rich SEI on Li metal to improve the uniformity of Li deposition.A composite Li anode with a PAN host delivers 145 cycles compared with 90 cycles when a non-polar host is employed.Moreover,60 cycles are demonstrated in a 1:0 Ah pouch cell without external pressure.This work provides a fresh guidance for designing practical composite Li anodes by unraveling the vital role of the synergy between a 3 D host and solvent molecules for regulating a robust SEI.
基金supported by the Beijing Municipal Natural Science Foundation (Z20J00043)the National Natural Science Foundation of China (22061132002, 21825501)+4 种基金the China Postdoctoral Science Foundation (2021M700404)the Seed Fund of Shanxi Research Institute for Clean Energy (SXKYJF015)the Beijing Municipal Natural Science Foundation (JQ20004, L182021)the Beijing Institute of Technology Research Fund Program for Young Scholarsthe Tsinghua University Initiative Scientific Research Program。
文摘The interfacial stability of lithium metal anodes dictated by solid electrolyte interphase(SEI) is essential for long-cycling high-energy-density lithium–sulfur batteries. Nevertheless, critical components of SEI for interfacial stabilization are particularly indistinct. Herein, the effect of various sulfur-containing components in SEI for stabilizing lithium metal anodes is disclosed in lithium–sulfur batteries. High-valence sulfur-containing species(Li_(2)SO_(3) and Li_(2)SO_(4)) in SEI are conducive to uniform lithium deposition and stabilizing lithium metal anodes. In contrast, low-valence sulfur-containing species(Li_(2)S_(3) and Li_(2)S_(4)) in SEI result in aggressive lithium dendrites and dead lithium. This work identifies the role of sulfurcontaining components in SEI for stabilizing lithium metal anodes and provides rational design principles of SEI for protecting lithium metal anodes in practical lithium–sulfur batteries.
基金National Research Foundation,Grant/Award Numbers:NRF‐2018R1A5A1025594,NRF‐2022M3J1A1062644。
文摘The application of Li metal anodes in rechargeable batteries is impeded by safety issues arising from the severe volume changes and formation of dendritic Li deposits.Three‐dimensional hollow carbon is receiving increasing attention as a host material capable of accommodating Li metal inside its cavity;however,uncontrollable and nonuniform deposition of Li remains a challenge.In this study,we synthesize metal–organic framework‐derived carbon microcapsules with heteroatom clusters(Zn and Ag)on the capsule walls and it is demonstrated that Ag‐assisted nucleation of Li metal alters the outward‐to‐inward growth in the microcapsule host.Zn‐incorporated microcapsules are prepared via chemical etching of zeolitic imidazole framework‐8 polyhedra and are subsequently decorated with Ag by a galvanic displacement reaction between Ag^(+) and metallic Zn.Galvanically introduced Ag significantly reduces the energy barrier and increases the reaction rate for Li nucleation in the microcapsule host upon Li plating.Through combined electrochemical,microstructural,and computational studies,we verify the beneficial role of Ag‐assisted Li nucleation in facilitating inward growth inside the cavity of the microcapsule host and,in turn,enhancing electrochemical performance.This study provides new insights into the design of reversible host materials for practical Li metal batteries.
基金the financial support from The National Key Research and Development Program of China(2022YFB3305402)The National Natural Science Foundation of China(12272072)+1 种基金The Key Project of Chongqing Technology Innovation and Application Development(CSTB2022TIAD-KPX0037)Research Project of the State Key Laboratory of Intel igent Vehicle Safety Technology(NVHSKL-202207)
文摘The accurate representation of lithium plating and aging phenomena has posed a persistent challenge within the battery research community.Empirical evidence underscores the pivotal role of cell structure in influencing aging behaviors and lithium plating within lithium-ion batteries(LIBs).Available lithium-ion plating models often falter in detailed description when integrating the structural intricacies.To address this challenge,this study proposes an innovative hierarchical model that intricately incorporates the layered rolling structure in cells.Notably,our model demonstrates a remarkable capacity to predict the non-uniform distribution of current density and overpotential along the rolling direction of LIBs.Subsequently,we delve into an insightful exploration of the structural factors that influence lithium plating behavior,leveraging the foundation laid by our established model.Furthermore,we easily update the hierarchical model by considering aging factors.This aging model effectively anticipates capacity fatigue and lithium plating tendencies across individual layers of LIBs,all while maintaining computational efficiency.In light of our findings,this model yields novel perspectives on capacity fatigue dynamics and local lithium plating behaviors,offering a substantial advancement compared to existing models.This research paves the way for more efficient and tailored LIB design and operation,with broad implications for energy storage technologies.
基金supported by the National Natural Science Foundation of China (U1664255, 21875022, 51802020, U1564206)the National Key R&D Program of China (2016YFB0100301)+2 种基金the Science and Technology Innovation Foundation of Beijing Institute of Technology Chongqing Innovation Center (2020CX5100006)the Young Elite Scientists Sponsorship Program by CAST (2018QNRC001)support from Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘The low-temperature performance of Li-ion batteries(LIBs) has important impacts on their commercial applications. Besides the metallic lithium deposition, which is regarded as one of the main failure mechanisms of the LIBs at low temperatures, the synergistic effects originating from the cathode, anode, electrolyte, and separators to the batteries are still not clear. Here, the 21700-type cylindrical batteries were evaluated at a wide range of temperatures to investigate the failure mechanism of batteries. Voltage relaxation, and the post-mortem analysis combined with the electrochemical tests, unravel that the capacity degradation of batteries at low temperature is related to the lithium plating at graphite anodes,the formation of unsatisfied solid deposited/decomposed electrolyte mixture phase on the anode, the precipitation of solvent in the electrolytes and the block of separator pores, and the uneven dissolved transition metal-ions from the cathode. We hope this finding may open up a new avenue to alleviate the capacity degradation of advanced LIBs at low temperatures and shed light on the development of outstanding low-temperature LIBs via simultaneous optimization of all the components including electrodes, electrolytes and separators.
基金P.R.Budarapu is thankful to the Indian Institute of Technology Bhubaneswar,India,for funding this study through grant number SP097.
文摘The performance and lifespan of Li-ion batteries used in electric vehicles are influenced by operating and environmental conditions.An understanding of the mechanisms leading to performance degradation and capacity fading can aid in the design of better battery systems.In the present study,numerical models are developed to estimate the capacity fading,battery performance,and residual life.Furthermore,key associated parameters are identified as state of charge,charging protocols,and temperature.Later on,a deep machine learning(DML)model consisting of one input,four hidden,and one output layer is developed to estimate the residual life of a battery system.The five input parameters considered include voltage,current,temperature,number of cycles,and time,apart from residual life as the output parameter.The proposed DML model consists of five dense layers and three dropout layers with 2889 trainable parameters in total,with higher neuron counts in initial layers to process diverse inputs and fewer neurons in later layers to ensure compact feature representation as well as to make better and faster predictions.Results from the numerical and DML models are compared to the reported experimental results,where good agreement is observed.Thus,the developed model is tested on Lithium based Nickel Manganese Cobalt Oxide and Nickel Cobalt Aluminum Oxide batteries,for which parametric studies are performed to investigate the influence of the operating temperature,rate of charge/discharge,and pulse charging on the battery life.Therefore,the technologies proposed in this study can contribute to the development of intelligent battery management systems,enabling enhanced performance,and hence prolonged life of battery systems.
