Fast Charging Conditions Research Articles

Effect of fast charging on degradation and safety characteristics of lithium-ion batteries with LiFePO4 cathodes

Fast charging compatibility is a desirable feature for batteries to shape a promising future in our rechargeable world. Enabling fast charging of advanced energy-dense Li-ion batteries for growing electric vehicle (EV) markets depends on the breakthrough of material chemistry and optimization of charging strategy. Lithium iron phosphate (LiFePO4, or LFP) is a pivotal cathode material in state-of-the-art EV batteries due to the merits of high thermal stability, long cycle lifetime, and high-temperature performance. However, degradation-safety interactions of LFP-based Li-ion batteries under fast charging conditions and low temperatures remain elusive. In this study, we cycle LFP cells under different fast charging strategies and thermal environments to understand their effects on degradation pathways, where the capacity, voltage, temperature, coulombic inefficiency, internal resistance, and impedance spectroscopy are evaluated. Half-cell studies are implemented to assess electrode-level capacity retentions. Post-mortem analyses are conducted to reveal physicochemical changes in electrodes. Accelerating rate calorimeter tests are carried out to measure evolutions of cell-level thermal instabilities after fast charging tests. This research article highlights the significant roles of graphite-centric lithium plating and LFP-centric transition metal dissolution in driving substantial electrochemical degradations, suggesting that a mild low temperature does not necessarily reduce the LFP cell lifetime.

Design of Localized High Concentration Electrolytes for Fast-Charging Lithium-Ion Batteries.

Localized high-concentration electrolytes (LHCEs) have emerged as a promising class of electrolytes to improve the cycle life and energy density of lithium-ion batteries (LIBs). While their application in batteries with lithium-metal anodes is extensively investigated, their behavior in systems with graphite anodes has received less research attention. Herein, the behaviors of four electrolytes in Graphite | LiNiO2 cells are compared. By systematically varying the electrolyte compositions, the impacts of the solvation structure, solvent composition, and salt composition of LHCEs are identified on the rate capability, stability, and propensity for lithium plating in LIB full-cells. It is found that while the solvation structure and solvent composition each play an important role in determining rate capability, the substitution of LiPF6 salt with LiFSI maximizes the rate capability and suppresses irreversible lithium plating. It is now demonstrated via constant-potential cycling, that an appropriately formulated LHCE can, therefore, maintain high reversible capacity and safety under arbitrarily fast charging conditions.

A Temporal Fusion Memory Network-Based Method for State-of-Health Estimation of Lithium-Ion Batteries

As energy storage technologies and electric vehicles evolve quickly, it becomes increasingly difficult to precisely gauge the condition (SOH) of lithium-ion batteries (LiBs) during rapid charging scenarios. This paper introduces a novel Time-Fused Memory Network (TFMN) for SOH estimation, integrating advanced feature extraction and learning techniques. Both directly measured and computationally derived features are extracted from the charge/discharge curves to simulate real-world fast-charging conditions. This comprehensive process captures the complex dynamics of battery behavior effectively. The TFMN method utilizes one-dimensional convolutional neural networks (1DCNNs) to capture local features, refined further by a channel self-attention module (CSAM) for robust SOH prediction. Long short-term memory (LSTM) modules process these features to capture long-term dependencies essential for understanding evolving battery health patterns. A multi-head attention module enhances the model by learning varied feature representations, significantly improving SOH estimation accuracy. Validated on a self-constructed dataset and the public Toyota dataset, the model demonstrates superior accuracy and robustness, improving performance by 30–50% compared to other models. This approach not only refines SOH estimation under fast-charging conditions but also offers new insights for effective battery management and maintenance, advancing battery health monitoring technologies.

Investigation of 40 Ah Prismatic Batteries Operating Under Fast-Charge Conditions Using Operando Synchrotron XRD Technique

The pressing challenges posed by the energy crisis and the impact of climate change have forced a gradual replacement of traditional internal combustion engine (ICE) automobile powertrains with electrochemical energy storage devices. However, a boost of the electric vehicles (EVs) market, by significant battery performance enhancements are consistently required, primarily due to numerous persistent concerns. One of the key features targeted by battery and EVs industries is the rapid charging capability, making EVs more competitive with the quick refueling of traditional gasoline vehicles. Notably, despite the clear benefits of fast charging technology, the accelerated battery degradation after fast and extreme fast charging raises on top of the drawbacks of this technology. Therefore, understanding of heterogeneity and structural transformations within battery systems is of high interest.In this regard, we attempt to investigate the structural properties of a LiNi1/3Mn1/3Co1/3O2 (NMC111) /graphite fresh industrial prismatic cell using synchrotron XRD under fast charge conditions. The investigated battery is a PHEV cell with an experimental capacity of 40 Ah. It was taken from a range rover vehicle pack after being disassembled. The evolution of the composite anode and cathode structures was followed by operando wide-angle X-ray scattering (WAXS). Using this approach, we were able to measure and quantify the different phases of graphite and NMC111 lithiation/delithiation at various potentials by analyzing the corresponding Bragg peaks. By that, we were able to detect some heterogeneities in the degree of lithiation/delithiation within the cell upon charge. In addition, a comparison between a fresh cell and another aged cell, with a state of health (SOH) of 88%, was made in order to investigate the effect of aging under fast charging conditions on the performance of the industrial LIBs.

Physics-Based State of Health Prediction of Lithium-Ion Battery during Fast Charging

Electrification of the transportation sector and increased use in consumer electronics have driven the increasing demand for lithium-ion batteries (LiBs) (1). Despite their high energy density and long service life, LiBs suffer from capacity degradation due to continuous growth of solid electrolyte interface (SEI) layer and plating of lithium on the anode surface. Graphite, the anode in most LiBs, has a high tendency to catalyze the degradation of the electrolyte consisting of LiPF6 and ethylene carbonate to form an SEI of Li-rich carbonate, phosphate, and fluoride compounds (2, 3). The SEI film grows during service due to the deposition of reaction products and repeated cycles of damage and reformation due to the contraction and expansion associated with volume changes during Li-ion intercalation and deintercalation. Additionally, fast or low-temperature charging of batteries results in lithium plating on the anode surface because the elevated concentration of Li+ on the anode surface results in graphite potential falling below 0V vs. Li+/Li and increased likelihood of Li deposition compared to intercalation (4). Lithium loss due to the side reactions of SEI growth and plating contributes to capacity loss and may increase the likelihood of battery failure. Hence, accurate modeling of the side reactions is required to determine the state of health (SOH) and predict the remaining capacity of LiBs during operation (5).We report an experimentally validated single particle model (SPM) to estimate the influence of SEI growth and Li plating on the capacity changes in Lithium Cobalt Oxide (LCO)/Carbon cells during repeated cycling (6-8). The SPM model idealizes each electrode as a single particle to approximate the cell response. A. Sarkar et al. (5) included the influence of SEI growth, plating, SEI fracture, and temperature in the SPM model to determine the influence of the side reactions on battery performance. The parameters corresponding to side reactions, such as the SEI film growth rate, conductivity of the SEI film, and reversibility of the plating reaction, were determined through comparison of numerical predictions of cell voltage and capacity change with experimental response measured at charging rates of 0.1C and fast charging rate of 2C on PowerStream 35 mAh LCO/C coin cells (Lir2032) as shown in Figure 1. In addition, the coin cells were subjected to charge/discharge experiments at charging rates varying from 0.1C – 5C for 100 cycles. Experimental measurements of the cell capacity changes were compared to model predictions for the different charging rates to validate the modeling assumptions and determine the efficacy of the estimated parameters in describing the cell degradation. The agreement between the model prediction and measured experimental response showed that the single particle model augmented with side reaction mechanisms can describe the cell degradation and is suitable for predicting the remaining capacity and safety of LiBs subjected to a range of charging rates. The model can also predict the accumulation of irreversibly plated lithium on the anode surface during repeated fast charging. The amount of plated lithium determines the severity of dendritic growth, and thus, model predictions of lithium accumulation may be used to estimate the likelihood of battery failure under fast charging conditions. Acknowledgment:This work was supported by the National Science Foundation, Iowa State University, and University of Connecticut.

External Cooling and Degradation Interplay in Lithium-Ion Battery Fast Charging

Fast charging of Li-ion batteries involves key challenges such as lithium plating, mechanical stress formation, high temperature rise, and non-uniform temperature distributions. The advancement of thermal management systems to maintain an optimal cell temperature distribution and minimize degradation is critical to enable fast charging. This work analyzes the various degradation modes, including lithium plating, solid electrolyte interphase growth, and mechanical stresses in large-format Li-ion cells during fast charging, and delineates their dependence on external cooling conditions. Based on the cell design and operating conditions, unique attributes related to the evolution of internal thermal gradients, spatiotemporal lithium plating response, and the formation of mechanical stress hotspots are delineated. Further, optimal external cooling configurations that enable longer life and safety under fast charging conditions are determined. The study provides guidance toward the design of next-generation battery thermal management systems for Li-ion batteries with fast charging capabilities.

Digital Twin‐Assisted Degradation Diagnosis and Quantification of NMC Battery Aging Effects During Fast Charging

AbstractA comprehensive understanding of aging mechanisms and degradation diagnosis under fast charging in battery electric vehicles is needed. However, there is a lack of tools to capture both macroscopic and microscopic parameters, still focusing on experiment results analysis. To get a comprehensive degradation insight for improved service life, this study explores aging mechanisms in LiNi0.5Co0.2Mn0.3O2 graphite batteries under different fast charging conditions (0.6C to 2C) for up to 1000 equivalent full cycles (EFCs). An improved digital twin is used to quantify aging effects and identify aging modes, combining electrochemical techniques with post‐mortem analysis for assessing chemical and structural degradation. After 1000 EFCs, the dominant aging modes are loss of active material (LAM) in the negative electrode and loss of lithium inventory (LLI), surpassing LAM in the positive electrode. Compared to constant current charging, multistep fast charging effectively mitigates Li plating effects and graphite cracking, resulting in a 13% reduction in LAM. Additionally, optimizing the depth of discharge leads to at least 4% reductions in LLI and 16% in LAMpos. This study proves the electrochemical digital twin's potential for quantifying aging effects and serves as a basis for future physics‐informed machine learning to predict aging behavior and modes.

Over-Lithiation Regulation of Silicon-Based Anodes for High-Energy Lithium-Ion Batteries.

Mitigating the growth of dendritic lithium (Li) metal on silicon (Si) anodes has become a crucial task for the pursuit of long-term cycling stability of high energy density Si-based lithium-ion batteries (LIBs) under fast charging or other specific conditions. While it is widely known that Li metal plating on Si-based anodes may introduce inferior cycling stability and cause safety concerns, the evolution of the anode/material structure and electrochemical performance with Li metal plating remains largely unexplored. A comprehensive quantitative investigation of the hybrid Li storage mechanism, combining the Li alloying/dealloying mechanism and plating/stripping mechanism, has been conducted to explore the effect of Li plating on Si-based anodes. The findings reveal that Li plating/stripping accounts for the decay of the overall Coulombic efficiency and cycling stability of the hybrid Li storage mechanism. Furthermore, alloying reactions occurring below 0 V encourage the formation of crystalline Li15Si4, which subsequently exacerbates voltage hysteresis. The performance decay is amplified as the ratio of Li plating/stripping capacity increases, or in other words, as the over-lithiation level rises, thereby posing a threat to the battery's cycling stability. These results provide valuable insights into the design of advanced Si-based electrodes for high energy density LIBs.

Impact of fast charging and low-temperature cycling on lithium-ion battery health: A comparative analysis

Fast charging and low temperatures create harsh conditions that promote lithium deposition on graphite anodes, which significantly accelerates the degradation of the battery's state of health (SoH) and eventually could result in safety concerns. In this work, commercial lithium-ion batteries are investigated under fast charging conditions and at low environmental temperatures. The findings are compared with lithium-ion battery cycled under ambient temperature conditions. The fast charging and low temperatures result in dead lithium formation, which is then characterized by electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). The low-temperature cycled battery exhibits significant growth of series resistance by an average of 73 %. In comparison, growth in charge transfer resistance is 16 %, and no significant change was observed in solid electrolyte interface (SEI) resistance due to the formation of dead lithium, compared to the battery cycled at ambient temperature. SEM images also confirm the dead lithium formation. The results provide insight into battery degradation in the case of high current due to low temperature and could lead to a better understanding of the degradation mechanism.

Coupling Antisite Defect and Lattice Tensile Stimulates Facile Isotropic Li-Ion Diffusion.

Despite widely used as a commercial cathode, the anisotropic 1D channel hopping of lithium ions along the [010] direction in LiFePO4 prevents its application in fast charging conditions. Herein, an ultrafast nonequilibrium high-temperature shock technology is employed to controllably introduce the Li-Fe antisite defects and tensile strain into the lattice of LiFePO4. This design makes the study of the effect of the strain field on the performance further extended from the theoretical calculation to the experimental perspective. The existence of Li-Fe antisite defects makes it feasible for Li+ to move from the 4a site of the edge-sharing octahedra across the ab plane to 4c site of corner-sharing octahedra, producing a new diffusion channel different from [010]. Meanwhile, the presence of a tensile strain field reduces the energy barrier of the new 2D diffusion path. In the combination of electrochemical experiments and first-principles calculations, the unique multiscale coupling structure of Li-Fe antisite defects and lattice strain promotes isotropic 2D interchannel Li+ hopping, leading to excellent fast charging performance and cycling stability (high-capacity retention of 84.4% after 2000 cycles at 10 C). The new mechanism of Li+ diffusion kinetics accelerated by multiscale coupling can guide the design of high-rate electrodes.

Initial formaldehyde generation as a predictive marker for long-term stability of Ni-rich Li-ion batteries under abusive conditions

Electrolyte decomposition significantly impacts the long-term stability of Li-ion batteries, generating liquid and gaseous byproducts. This study focuses on formaldehyde formation, a critical byproduct from CO2 reduction in Ni-rich Li-ion batteries. Through experimental and computational analyses, formaldehyde emerges from carbonate-based electrolyte decomposition. Examining overcharge, over-discharge, and fast charging conditions, formaldehyde concentration sharply increases under overcharge, indicating severe electrolyte breakdown, while over-discharge shows a gradual rise. Fast charging similarly elevates formaldehyde levels, underscoring the link between electrolyte decomposition and abusive conditions. Importantly, this research proposes utilizing formaldehyde concentration from the initial cycle as a predictive marker for assessing long-term Ni-rich Li-ion battery stability trends. Elevated initial formaldehyde indicates potential capacity fade and accelerated degradation, enabling proactive mitigation strategies. The study elucidates mechanisms governing formaldehyde formation, providing a foundation for developing electrolyte formulations and electrode materials with enhanced decomposition resistance and improved stability. This investigation contributes to the fundamental understanding of electrolyte decomposition in Ni-rich Li-ion batteries and presents a novel approach to predicting long-term performance based on initial formaldehyde measurements, advancing high-performance and reliable energy storage solutions.

Effect of fast charging on degradation and safety characteristics of lithium-ion batteries with LiNixCoyMnzAl1-x-y-zO2 cathodes

Fast charging compatibility is an important technical aspect required of advanced lithium-ion (Li-ion) batteries to lead the revolution and increase the adoption of electric vehicles. Although substantial material-level innovations have greatly promoted the widespread employment of fast charging rates for Li-ion batteries, the unfavorable rapid degradation and cell-level thermal instability are still bottlenecks for commercial success. In this study, fast-charging induced aging mechanisms and thermal safety characteristics of Li-ion batteries with quaternary energy-dense LiNixCoyMnzAl1-x-y-zO2 (NCMA) cathodes are comprehensively investigated. Promising fast-charge strategies under different thermal environments are applied to reveal their specific adverse side effects on electrochemical performances and cell lifetime. Post-mortem analysis is conducted to understand the distributions, microstructures, and chemical states of electrodepositions on cell components. Cell-level thermal safety evaluations are carried out based on accelerating rate calorimeter tests to determine evolutions of thermal safety hazards as a result of imposed fast charging conditions. This research highlights the significant role of lithium plating and aluminum dissolution in accelerating the thermo-electrochemical failure of the chosen NCMA-based Li-ion chemistry, providing new insights on degradation-safety interactions and effective mitigation strategies under fast charging conditions.

Recent advancements and performance implications of hybrid battery thermal management systems for Electric Vehicles

Electric Vehicles (EVs) can contribute significantly toward the reduction of environmental emissions caused by traditional Internal Combustion Engines (ICEs), as well as it reduces the reliance on conventional fossil fuels. Lithium-ion batteries (LiBs) are generally preferred for EVs due to their superior energy density, specific power output, and longer lifespan. LiBs are most effective and achieve optimal performance within a specific temperature range of 15-35 °C. An efficient Battery Thermal Management System (BTMS) is necessary to dissipate the heat produced in the battery during continuous charging and discharging process, which ultimately determines the operating range and life cycle of the battery. The hybrid battery thermal management system is becoming increasingly popular as it tackles the downsides and capitalizes on the upsides of individual conventional battery thermal management systems. Although hybrid Battery Management Systems are often mentioned in review articles, there is a lack of detailed or specialized discussions specifically on hybrid BTMS for electric vehicles. This article summarizes the current state-of-the-art and recent advancements in hybrid battery thermal management of LiBs and discusses the performance implications of a hybrid battery thermal management system. The study extensively examines hybrid BTMSs, designed to enhance the thermal performance of traditional BTMSs to cope with the stringent thermal requirements in high ambient temperatures and fast charging conditions. Lastly, the article critically evaluates and discusses the different BTMSs, emphasizing the future prospects, challenges, and recommendations in the BTMS field. The review's findings will assist researchers in determining the future direction of next-generation LiB thermal management systems for high-power electric vehicles.

Comparative Evaluation of Liquid Cooling-Based Battery Thermal Management Systems: Fin Cooling, PCM Cooling, and Intercell Cooling

The escalating demand for electric vehicles and lithium-ion batteries underscores the critical need for diverse battery thermal management systems (BTMSs) to ensure optimal battery performance. Despite this, a comprehensive comparative analysis remains absent. This study seeks to assess and compare the thermal and hydraulic performances of three prominent BTMSs: fin cooling, intercell cooling, and PCM cooling. Simulation models were meticulously developed and experimentally validated, with each system’s design parameters optimized under identical volumes to ensure equitable comparisons. In the context of fast-charging conditions, intercell cooling consistently met and even surpassed the desired target temperature, reducing the maximum temperature to 30.6°C with an increasing flow rate, while fin cooling faced challenges. Effective control of coolant temperature emerged as a critical factor for achieving optimal PCM cooling, with a potential reduction in temperature difference by 4.3 K. Despite exhibiting higher power consumption, intercell cooling demonstrated the most efficient cooling effect during fast charging. Considering the BTMS weight, fin cooling exhibited the lowest energy density, approximately half that of other methods. Addressing precooling and preheating conditions for high and low temperatures, the intercell method proved adept at meeting temperature requirements with minimal power consumption in significantly shorter durations. Conversely, the practicality of using PCM at high temperatures was deemed challenging.

Unraveling the New Role of Manganese in Nano and Microstructural Engineering of Ni‐Rich Layered Cathode for Advanced Lithium‐Ion Batteries

AbstractSubstantial endeavors are dedicated to advance the electrochemical performance of Ni‐rich Li[Ni1−x−yCoxMny]O2 (NCM) and Li[Ni1−x−yCoxAly]O2 (NCA) cathode, with a particular focus on doping, aimed at addressing cycling durability and thermal stability of the cathodes. Mn is widely considered an attractive dopant because of its abundance and considerably lower cost than other dopant candidates. However, despite the long history of research, the role of Mn doping remains poorly understood, confined to the historical level, and associated with crystal structural and chemical aspects. Herein, the role of Mn doping beyond its classical role is redefined, particularly in terms of cathode microstructure. Introducing excess Mn during calcination significantly engineers the nano‐ and micro‐level structural features of the peripheral grains of the Li[Ni0.910Co0.079Al0.011]O2 cathode. The microstructural modification achieved by doping with 4 mol% Mn significantly improves the electrochemical cycling performance of the cathode, extending the capacity retention up to 76.5% after 1000 cycles under fast charging conditions (3 C and 45 °C). Hence, by providing an alternative approach to redesign the structural features of the cathode, Mn doping offers a significant step toward the sustainable development of high‐performance Ni‐rich Li[Ni1−x−y−zCoxMnyAlz]O2 (NCMA) cathodes for next‐generation lithium‐ion batteries.

"Fast-Charging" Anode Materials for Lithium-Ion Batteries from Perspective of Ion Diffusion in Crystal Structure.

"Fast-charging" lithium-ion batteries have gained a multitude of attention in recent years since they could be applied to energy storage areas like electric vehicles, grids, and subsea operations. Unfortunately, the excellent energy density could fail to sustain optimally while lithium-ion batteries are exposed to fast-charging conditions. In actuality, the crystal structure of electrode materials represents the critical factor for influencing the electrode performance. Accordingly, employing anode materials with low diffusion barrier could improve the "fast-charging" performance of the lithium-ion battery. In this Review, first, the "fast-charging" principle of lithium-ion battery and ion diffusion path in the crystal are briefly outlined. Next, the application prospects of "fast-charging" anode materials with various crystal structures are evaluated to search "fast-charging" anode materials with stable, safe, and long lifespan, solving the remaining challenges associated with high power and high safety. Finally, summarizing recent research advances for typical "fast-charging" anode materials, including preparation methods for advanced morphologies and the latest techniques for ameliorating performance. Furthermore, an outlook is given on the ongoing breakthroughs for "fast-charging" anode materials of lithium-ion batteries. Intercalated materials (niobium-based, carbon-based, titanium-based, vanadium-based) with favorable cycling stability are predominantly limited by undesired electronic conductivity and theoretical specific capacity. Accordingly, addressing the electrical conductivity of these materials constitutes an effective trend for realizing fast-charging. The conversion-type transition metal oxide and phosphorus-based materials with high theoretical specific capacity typically undergoes significant volume variation during charging and discharging. Consequently, alleviating the volume expansion could significantly fulfill the application of these materials in fast-charging batteries.

Surface fluorinated graphite suppressing the lithium dendrite formation for fast chargeable lithium ion batteries

Developing lithium-ion batteries with high power and fast charging features has been highlighted as an essential research area to address growing energy demands for portable electronics and long-range electric vehicles. The commercial graphite anode has been recognized as a competent material owing to its benefits, including a long cycle life, high columbic efficiency, and low volume expansion. However, the intrinsic features of their intercalation kinetics render them highly susceptible to lithium deposition, resulting in poor cycle stability at fast charging conditions. In this study, we propose a simple thermal fluorine treatment of flake-type graphite to produce fluorine-doped-flake graphite. We observed the fluorine treatment improves the Li+ ion intercalation kinetics and reduces the lithium deposition and dendrite growth upon fast charging conditions. As a result, enhanced lithiation behavior was observed, with a high specific capacity of 348.3 mAh g−1 and a good rate capability of 66 % at 2C-rate in half-cell conditions. Furthermore, a full cell demonstrated outstanding cycle stability with 83.5 % capacity retention at 2C even after 950 cycles. Our findings emphasize that fluorine doping in graphite could be a straightforward and practical approach to mitigate Li deposition issues and enhance the fast charge kinetics of graphite-based commercial Li-ion batteries.

Low-Temperature Molten Salt Electrochemical CO2 Upcycling for Advanced Energy Materials.

One strategy for addressing the climate crisis caused by CO2 emissions is to efficiently convert CO2 to advanced materials suited for green and clean energy technology applications. Porous carbon is widely used as an advanced energy storage material because of its enhanced energy storage capabilities as an anode. Herein, we report electrochemical CO2 upcycling to solid carbon with a controlled microstructure and porosity in a ternary molten carbonate melt at 450 °C. Controlling the electrochemical parameters (voltage, temperature, cathode material) enabled the conversion of CO2 to porous carbon with a tunable morphology and porosity for the first time at such a low temperature. Additionally, a well-controlled morphology and porosity are beneficial for reversible energy storage. In fact, these carbon materials delivered high specific capacity, stable cycling performances, and exceptional rate capability even under extremely fast charging conditions when integrated as an anode in lithium-ion batteries (LIBs). The present approach not only demonstrated efficient upcycling of CO2 into porous carbon suitable for enhanced energy storage but can also contribute to a clean and green energy technology that can reduce carbon emissions to achieve sustainable energy goals.

Challenges and Strategies of Fast-Charging Li-Ion Batteries with a Focus on Li Plating

As the world enters into the era of electrifying transportation for cleaner energy, lithium-ion battery (LIB)-powered electric vehicles have drawn great attention in recent years. However, the fast-charging capability of LIBs has long been regarded as the technological obstacle to the wider adoption of battery electric vehicles (BEVs) in the market. A substantial challenge associated with fast charging is the formation of Li plating on the graphite anode as it is the major contributor of side reactions during cell operations. In this review, the fundamentals of Li plating and corresponding influencing factors (including state of charge [SOC], charging current density, temperature, and N/P ratio) for the Li-ion intercalation process are first elucidated under fast-charging conditions. Furthermore, conventional strategies to suppress Li plating by enhancing ion transport kinetics between interface and electrode through anode engineering and electrolyte design are also summarized and analyzed. Then, innovative strategies for achieving ultrahigh SOC of anodes by regulating Li plating morphology on host materials to construct hybrid anode storage are discussed in detail. Two types of strategies are compared in terms of cell performance, process simplicity, and safety concerns. Last, we highlight some research orientations and perspectives pertaining to the development of hybrid anode storage, providing effective approaches to address Li plating issues for fast-charging LIBs.

Modeling Lithium Plating Onset on Porous Graphite Electrodes Under Fast Charging with Hierarchical Multiphase Porous Electrode Theory

Lithium plating during fast charging of porous graphite electrodes in lithium-ion batteries accelerates degradation and raises safety concerns. Predicting lithium plating is challenging due to the close redox potentials of lithium reduction and intercalation, obscured by the nonlinear dynamics of electrochemically driven phase separation in hierarchical pore structures. To resolve dynamical resistance of realistic porous graphite electrodes, we introduce a model of porous secondary graphite particles to the multiphase porous electrode theory (MPET), based on electrochemical nonequilibrium thermodynamics and volume averaging. The resulting computational framework of “hierarchical MPET” is validated and tested against experimental data over a wide range of fast charging conditions and capacities. With all parameters estimated from independent sources, the model is able to quantitatively predict the measured cell voltages, and, more importantly, the experimentally determined capacity for lithium plating onset at fast 2C to 6C rates. Spatial and temporal heterogeneities in the lithiation of porous graphite electrodes are revealed and explained theoretically, including key features, such as idle graphite particles and non-uniform plating, which have been observed experimentally.