Battery Safety Research Articles

Thermal Performance of a Cylindrical Li[Ni0.6Co0.2Mn0.2]O2/Graphite Battery based on the Electrochemical-Thermal Coupling Model

The thermal safety of lithium-ion batteries has garnered significant attention due to its pivotal role in the field of new energy. In this work, a three-dimensional electrochemical-thermal coupling model based on the P2D model was established for predicting the thermal performance. The charge-discharge and temperature rise experiments via 18650 cylindrical Li[Ni0.6Co0.2Mn0.2]O2 / graphite batteries are designed to confirm the rationality of the model. The simulation results show that the highest temperature of the battery surface during discharging at 1 C and 4 C are 42.85 °C and 61.25 °C, and the experimental results are 42.50 °C and 62.85 °C, respectively. The electrode heat generation mainly comes from the reaction heat of cathode and anode during 1 C charge process, the maximum power is 1.2 W and 0.6 W, respectively. In the discharge process, the cathode dominates the reaction contribution of 1.02 W and the reaction heat power from the anode is only 0.016 W. The capacity of heat dissipation can be increased by enhancing the convective heat transfer coefficient and air velocity within a reasonable range. The proposed electrochemical-thermal coupling model is valuable to evaluate the heat behavior and promote the battery development.

External short circuit of lithium-ion battery after high temperature aging

The microscopic and macroscopic changes of lithium-ion batteries after high temperature cycling and their effect on external short circuit (ESC) are studied in this study. The results indicate that solid electrolyte interphase and cathode electrolyte interphase cover the surface of anode and cathode. Transition metal, Mn is dissolved from the cathode. Capacity and resistance decreases and increases after cycling at high temperature. The safety of batteries after ESC is ranked as: 70 % state of health (SOH) > 100 % SOH > 80 % SOH > 90 % SOH. Thermal runaway only occurs to battery with 90 % SOH after ESC. Increase of resistance after cycling affects heat generation during ESC less. Onset temperature and thermal runaway temperature increases and decreases owing to solid electrolyte interphase growth and Mn dissolution. Compared to fresh battery, safety of battery with 70 % SOH after ESC increases. Fast discharging causes side reactions for aged batteries, which also generate heat. The heat generation effect of fast discharging decreases with the decrease of SOH after 90 % SOH. Local micro internal short circuit causes more heat generation for aged batteries. The results are important for safety control of lithium-ion battery.

Research Progress of Microchannel Liquid Cooling Technology in the Application of Thermal Management of Prismatic Lithium Batteries (Withdrawn)

Lithium-ion batteries have significant advantages such as high energy density, long cycle life and low self-discharge rate. Therefore, they are ideal for energy storage in electric vehicles. However, lithium-ion batteries are very sensitive to temperature, which affects the battery's cycle life, efficiency, reliability and safety. During the charging and discharging process, a large amount of heat is generated inside the battery due to the electrochemical reaction and resistance, causing the battery temperature to rise. When the temperature gets too high, thermal runaway, electrolyte fire and explosions may occur. As battery energy density increases, the demand for efficient thermal management continues to increase, and a compact and efficient battery thermal management system is essential. This paper introduces the development status of different thermal management technologies, reviews the application of microchannel liquid-cooling technology in the thermal management of prismatic lithium batteries, discusses the current research direction and status of microchannel technology, and finally looks forward to the future research and development direction of microchannel technology.

Surface Engineering of Cathode Materials: Enhancing the High Performance of Lithium-Ion Batteries.

The development and application of lithium-ion batteries present a dual global prospect of opportunity and challenge. With conventional energy sources facing reserve shortages and environmental issues, lithium-ion batteries have emerged as a transformative technology over the past decade, owing to their superior properties. They are poised for exponential growth in the realms of electric vehicles and energy storage. The cathode, a vital component of lithium-ion batteries, undergoes chemical and electrochemical reactions at its surface that directly impact the battery's energy density, lifespan, power output, and safety. Despite the increasing energy density of lithium-ion batteries, their cathodes commonly encounter surface-side reactions with the electrolyte and exhibit low conductivity, which hinder their utility in high-power and energy-storage applications. Surface engineering has emerged as a compelling strategy to address these challenges. This paper meticulously examines the principles and progress of surface engineering for cathode materials, providing insights into its potential advancements and charting its development trajectory for practical implementation.

Critical Effects of Insoluble Additives in Liquid Electrolytes for Metal Batteries.

Rechargeable metal batteries have received widespread attention due to their high energy density by using pure metal as the anode. However, there are still many fundamental problems that need to be solved before approaching practical applications. The critical ones are low charge/discharge current due to slow ion transport, short cycle lifetime due to poor anode/cathode stability, and unsatisfied battery safety. To tackle these problems, various strategies have been suggested. Among them, electrolyte additive is one of the most widely used strategies. Most of the additives currently studied are soluble, but their reliability is questionable, and they can easily affect the electrochemical process, causing unwanted battery performance decline. On the contrary, insoluble additives with excellent chemical stability, high mechanical strength, and dimensional tunability have attracted considerable research exploration recently. However, there is no timely review on insoluble additives in metal batteries yet. This review summarizes various functions of insoluble additives: ion transport modulation, metal anode protection, cathode amelioration, as well as battery safety enhancement. Future research directions and challenges for insoluble solid additives are also proposed. It is expected this review will stimulate inspiration and arouse extensive studies on further improvement in the overall performance of metal batteries.

Reversible phase transition poly(benzyl methacrylate)/ionic liquid electrolytes for effective overheating protection in lithium batteries

Battery safety is influenced by various factors, with thermal runaway being one of the most significant concerns. While most studies have concentrated on developing one-time, self-activating mechanism for thermal protection, such as temperature-responsive electrodes, and thermal-shutdown separators, these methods only provide irreversible protection. Recently, reversible temperature-sensitive electrolytes have emerged as promising alternatives, offering both thermo-reversibility and self-protective properties. However, further research is crucial to fully understand these thermal-shutdown electrolytes. In this study, we propose lower critical solution temperature (LCST) phase behavior poly(benzyl methacrylate)/imidazolium-based ionic liquid mixtures to prepare temperature-sensitive electrolytes that provide reversible thermal shutdown protection of batteries. This electrolyte features an appropriate protection temperature (∼105°C) and responds quickly within a 1 min at 105°C, causing cells to hardly discharge as the voltage suddenly drops to 3.38 V, and providing efficient thermal shutdown protection within 30 min. Upon cooling back to room temperature, the battery regains its original performance. Additionally, the electrolyte exhibits excellent cycling stability with the capacity retention of the battery is 91.6% after 500 cycles. This work provides a viable solution for preventing batteries from thermal runaway triggered by overheating.

Battery Safety

Battery Safety

Innovative approaches to optimizing Li-Ion battery cooling performance using gas mixtures

This study investigates the critical issue of thermal management in lithium-ion batteries, a vital concern for enhancing battery performance, safety, and longevity. While more complex cooling systems like liquid cooling, phase change materials, and two-phase systems offer superior thermal performance due to their higher heat transfer capabilities, they come with significant drawbacks. These include increased system complexity, higher costs, added weight, and the potential for leaks or other failures that can compromise safety and reliability. Consequently, simpler air-based cooling systems are often preferred in many applications, despite their inherently lower h coefficient. To bridge the performance gap between air and liquid cooling without resorting to complex engineering solutions, this study focuses on enhancing the h coefficient of air-based systems using innovative refrigerant gas mixtures. The use of refrigerant gas mixtures, specifically a blend of R1234ze(E), nitrogen, and neon, as an alternative to traditional cooling methods was explored. The study employed a comprehensive FEM model and experimental validation to evaluate free and forced convection in a slender, vertical cylindrical configuration. To analyze the impact on convective heat transfer, the key parameters CRate, T0 and Tamb were systematically varied. A dimensionless analysis then evaluated how thermodynamic properties influence h coefficient. This analysis led to the derivation of a dimensionless heat transfer function h(ρ, Cp, k, μ). The study aimed to significantly improve the efficiency of h by optimizing the gas mixture properties. The “Mixture Study” identifies the optimal refrigerant composition, where a specific mixture α of 86 % R1234ze(E), and 14 % neon demonstrated the best balance between heat transfer efficiency and enhanced thermal capacity. The heat transfer coefficient increases by around 65 % during natural convection and by around 80 % during forced convection. The percentage reduction of the thermal difference in temperature reaches approximately 10 % with a maximum of 4 K in natural convection conditions and a maximum of 36.5 % and a reduction of approximately 10 K compared to air cooling alone, effectively maintaining the battery within the optimal operating range of 293.15 K to 333.15 K. Notably, this composition increased the thermal power absorbed by the mixture by over 100 % under the same thermal difference. This research therefore provides valuable insights for developing more effective gas cooling strategies that ultimately enhance the performance, safety, and durability of batteries in various applications. By integrating the benefits of both cooling methods, the study paves the way for innovative thermal management solutions in battery technology.

Highly hygroscopic needle-punched carbon fiber felt with high evaporative cooling efficiency and fire resistance for safe operation of ultrahigh-rate lithium-ion batteries

The effective thermal management of lithium-ion batteries is the key to ensuring their fast charging-discharging, safe and efficient operation. Herein, inspired by transpiration-driven water transport in plants, we report a highly hygroscopic needle-punched carbon fiber felt (HS/CFF) with high evaporative cooling efficiency and fire resistance for the safe operation of lithium-ion batteries working at ultrahigh-rate conditions. The three-dimensional fiber skeleton structure constructed by needle punching in the carbon fiber felt enables effective water transport and storage in HS/CFF, without any water leakage. At an ultra-high discharge rate of 10 C, HS/CFF can reduce the maximum temperature of commercial lithium-ion batteries by 18 °C, and can keep the battery temperature below 60 °C. During 500 cycles of charge-discharge, HS/CFF maintains stable evaporative heat dissipation performance, which helps to improve the safety of lithium-ion batteries and extend their service life. Moreover, HS/CFF remains non-combustible even under exposure to a flame (600-700 °C) for 10 min, and the HS/CFF can be reused after the burning test, with the original excellent heat dissipation effect unchanged. This flexible, fire-resistant cooling material offers a promising avenue for low-energy intelligent thermal management of lithium-ion batteries and other heat-generating electronic devices.

Passive battery thermal management and thermal safety protection based on hydrated salt composite phase change materials

Lithium-ion batteries (LIBs) are progressing towards higher energy densities, extended lifespans, and improved safety. However, battery thermal management systems are facing increased demand owing to high-rate charging and discharging, dynamic operating conditions, and heightened thermal safety concerns. Therefore, this paper proposes a novel composite phase change material (CPCM) comprising Na2SO4-10H2O as the core phase change material (PCM) and expanded graphite as the thermal conductivity enhancer. The CPCM offers high latent heat, superior thermal conductivity, and a two-stage temperature control function for battery thermal management and safety. The optimal mass CPCM ratio, determined through comprehensive characterization and thermal property tests, resulted in a melting point of 29.05°C, latent heat of 183.7 J.g−1, and high thermal conductivity of 3.926 W.m−1.K−1. During normal LIB operations, the CPCM efficiently absorbs and transfers heat, reducing the peak LIB temperature from 66 to 34°C at 15°C ambient temperature during a 3.7C high-rate discharge. Under dynamic conditions, the peak temperatures across the three cycles were consistently controlled at 36.7, 36.4, and 35.8°C, respectively. In a thermal runaway state, the thermochemical heat storage of hydrated salt dehydration effectively slowed LIB temperature increase, delaying the time to reach 130°C by 187 s. Suppression of the temperature rise outside the CPCM, combined with an extended dehydration plateau of up to 320 s, prevented the occurrence and propagation of thermal runaway in the battery.

Boron-containing cross-linker assisted single-ion conducting polymer electrolytes for high-performance and dendrite-free Li-metal batteries

Nowadays, single-ion conducting polymer electrolytes for high efficiency, stable, safe and dendrite-free Li-metal batteries are in great need to protect lithium metal anode. In this work, a boron-containing single-ion polymer electrolyte (BSPE), prepared by the copolymerization of allyl diglycol carbonate (ADC), lithium bis((trifluoromethyl)sulfonyl)amide (LiTFSI), and diisopropyl allylboronate (DPAB). The weak coordination interaction between Li+ and polar carbonate enhances Li+ transport ability. Further, the boron-containing cross-linker fixes the counter anions on the polymer backbones, limiting the movement of the anions and promoting the rapid and uniform Li+ transference. The BSPE with 3 wt% DPAB exhibits higher Li+ transference number (t+ = 0.77) and better ionic conductivity (1.36 × 10−4 S cm−1 at 25 °C) compared with that without DPAB. The wider electrochemical window (5.6 V vs. Li+/Li), stable polarization and suppressed lithium dendrites during the plating/stripping cycle at a current density of 0.2 mAcm−2 for 600 h provide the metal-lithium batteries with better safety and higher efficiency. In addition, the initial discharge capacity of LiFePO4/BSPE/Li is 140.7 mAh g−1 with 95.2 % coulombic efficiency, and the capacity retention still remains 98.7 % after 200 cycles at 0.1C. The excellent performance endows the BSPE with the potential application in high-performance lithium metal batteries.

Additive Manufacturing of Grid Reservoir-Integrated Anodes for Dendrite-Free, Safe, and Ultra-Low Voltage Zinc-Ion Batteries.

This work reports a novel 3D printed grid reservoir-integrated mesoporous carbon coordinatedsilicon oxycarbide hybrid composite (3DP-MPC-SiOC) to establish the zincophile interphase for controlling the dendrite formation. The customized 3D printed grid patterned structure inhibits Zn dendrite growth and achieves long-term stability with reduced voltage polarization due to homogeneous electric field distribution. The hybrid composite consisting of SiOC interpenetrated within carbon constructs a high zinc nucleation interphase, hence promoting uniform Zn2+ deposition and enhancing ionic diffusion with dendrite-free growth and a reduced nucleation energy barrier. As a result, the 3DP-MPC-SiOC@Zn symmetrical cell affords a highly reversible Zn plating/stripping and dendrite-free structure over 198h with an ultra-low voltage polarization. These inspiring performances endow the 3DP anode with a 3DP-VO cathode as a full battery, which shows a retention capacity of 78.8mAhg-1 (Coulombic efficiency: 94.04%) at 0.1Ag-1 and a large energy density of 41Whkg-1 at a power density of 1.2Wkg-1 (based on the total mass of electrode) after 120 cycles. This newly developed 3D printing of hybrid composite as an electrode is straightforward and scalable and provides a novel concept for realizing dendrite-free and stable rechargeable Zn-ion batteries.

An experimental study on lithium-ion electric vehicles battery packs behavior under extreme conditions for prevention of thermal runaway

The need for efficient and dependable lithium-ion battery packs has significantly increased as a result of the progressively rising sales of electric vehicles (EVs). Thermal management is one of the key factors in battery performance and durability. To avoid thermal deterioration, improve safety, and maximize system effectiveness, the battery pack's temperature must be carefully managed. These battery systems' potential for thermal runaway has raised concerns about how safely they can be operated in harsh environments. Environmental considerations, governmental laws, and developments in battery technology are driving the switch from internal combustion engines to electric automobiles. Lithium-ion batteries are sensitive to temperature variations and operating them outside the optimal temperature range can lead to accelerated degradation, reduced capacity, and compromised safety. Key performance indicators used to assess battery thermal management system effectiveness include temperature uniformity, cooling effectiveness, energy usage, and effect on battery life. This paper describes an experimental investigation that looked at how lithium-ion EV battery packs behaved in harsh environments. It also suggests a unique strategy to prevent thermal runaway by using materials like Transformer Oil (TO) and Phase Change Materials (PCM). A specially built experimental setup was created to undertake this inquiry in order to imitate several extreme situations, including high ambient temperatures. A lithium-ion (NMC) battery pack (7S3P) was put through the experimental phase's predicted harsh circumstances to see how it would react thermally. In order to obtain insight into the underlying mechanisms causing thermal runaway, the data acquired were evaluated, and crucial thermal metrics like temperature distribution, heat dissipation, and thermal gradients were studied. The experiment's findings showed that under extreme circumstances, conventional cooling techniques were ineffective in preventing thermal runaway, which resulted in serious safety risks and a reduction in battery performance. The suggested strategy, which incorporates PCM and TO, was then put into practice to fix these flaws and improve battery safety. Due to their ability to self-regulate, they served as components that prevented thermal runaway by limiting the rise in temperature under high-stress situations.

Research on monitoring and energy management systems for energy storage stations on the power generation side

Abstract Addressing the challenges of limited operational efficiency, inadequate battery safety, inflexible system scalability, inadequate AGC/AVC functionality, and low levels of intelligent operation and maintenance encountered by energy storage power stations integrated with new energy generation sources, this article delves into the pivotal role of these power stations on the generation side. It meticulously examines the network architecture, functional framework, and pivotal technologies underpinning the system. Furthermore, the article proposes a comprehensive monitoring and energy management system tailored specifically for energy storage on the generation side. The system uses micro-service architecture and container technology to realize the processing and storage of massive data. Through complete isolation of the information network and control network and millisecond communication with GOOSE, the charging and discharging response speed of the energy storage station is greatly improved. The power allocation algorithm based on device status recognition completes the system’s high-precision power control of PCS, and this system uses big data analysis and data mining technology to conduct a comprehensive statistical analysis of battery health status, power station operation efficiency, and equipment operation status and energy consumption. The design of the system has favorable technical and application guidance for the subsequent energy management design and engineering application of the energy storage power station.

A Multi-scale Framework for Advancing Battery Safety Through Early Calorimetric Analysis of Materials and Components

Batteries are the cornerstone of the global shift toward electrification, powering applications from passenger transportation, like electric vehicles (EVs), to load shifting of renewable energy generation at the grid level. The demand for batteries is accelerating, and is projected to nearly quadruple by 2030. In response to increasing battery demands, in particular demand for longer range EVs, higher energy density and specific energy alternatives to conventional Li-ion battery technologies are being researched. However, higher energy density directly correlates with an increased potential for higher peak temperatures on failure. In addition, safety evaluation of conventional and new battery technologies generally occurs late in development, often at the commercialization stage when mandated by stakeholders or industry standards. This approach can be costly and challenging as it may require a change to manufacturing processes, a re-design of the battery, and even a change in chemistry to meet safety requirements. This is critical; scale-up efforts alone can take tens to hundreds of millions of dollars and >5 years to achieve. Safety risks discovered after commercialization can significantly exacerbate those figures. Furthermore, safety is still a major risk with already commercialized Li-ion batteries. These risks hinder adoption, slow commercialization, and when they become issues, the outcome may result in recalls, fires, injuries, and even fatalities. Providing additional levers to proactively mitigate safety risk at the materials and components scale (e.g., composite cathode) will lead to considerable time and money savings in the long run.

Development and functional testing of battery management system algorithm for an electric bicycle using hardware in the loop testbench

An embedded Battery Management System (BMS) ensures the effective functionality and longevity of the vehicle battery systems. Testing the BMS using the Hardware in Loop (HIL) approach effectively increases safety and reduces product development time in the manufacturing sector. This research aims to develop an efficient battery management system with two-level protection for electric bicycles and test its functionality in the HIL configuration. The bicycle traction model and battery management system were first developed using a model-based design. Further, the model is tested and validated using battery emulators in the HIL methodology. The battery management system receives input data, such as current, voltage, and temperature, and monitors these parameters. The first level of protection involves the vehicle user receiving the warning when the monitoring parameters values exceed the given first safety threshold. As per the second safety threshold values, the BMS trips off the charging or discharging process when the voltage is 51V, the charge current is 5A, the discharge current is -5A and the IC temperature is 80 degrees. Also, BMS balances the cells in 3.84 min using passive balancing. Additionally, the BMS delivers a controlled current of 2.5A for safe battery charging. This methodology increases safety by reducing the potential risks of testing the BMS algorithms in the actual electric bicycle.

Self-Thermal Management in Filtered Selenium-Terminated MXene Films for Flexible Safe Batteries.

Li-ion batteries with superior interior thermal management are crucial to prevent thermal runaway and ensure safe, long-lasting operation at high temperatures or during rapid discharging and charging. Typically, such thermal management is achieved by focusing on the separator and electrolyte. Here, the study introduces a Se-terminated MXene free-standing electrode with exceptional electrical conductivity and low infrared emissivity, synergistically combining high-rate capacity with reduced heat radiation for safe, large, and fast Li+ storage. This is achieved through a one-step organic Lewis acid-assisted gas-phase reaction and vacuum filtration. The Se-terminated Nb2Se2C outperformed conventional disordered O/OH/F-terminated materials, enhancing Li+-storage capacity by ≈1.5 times in the fifth cycle (221 mAh·g-1 at 1 A·g-1) and improving mid-infrared adsorption with low thermal radiation. These benefits result from its superior electrical conductivity, excellent structural stability, and high permittivity in the infrared region. Calculations further reveal that increased permittivity and conductivity along the z-direction can reduce heat radiation from electrodes. This work highlights the potential of surface groups-terminated layered material-based free-standing flexible electrodes with self-thermal management ability for safe, fast energy storage.

Stress and Strain Characterization for Evaluating Mechanical Safety of Lithium-Ion Pouch Batteries under Static and Dynamic Loadings

The crashworthiness of electric vehicles depends on the response of lithium-ion cells to significant deformation and high strain rates. This study thoroughly explores the mechanical behavior due to damage of lithium-ion battery (LIB) cells, focusing on Lithium Nickel Manganese Cobalt Oxide (NMC) and Lithium Iron Phosphate (LFP) types during both quasi-static indentation and dynamic high-velocity penetration tests. Employing a novel approach, a hemispherical indenter addresses gaps in stress–strain data for pouch cells, considering crucial factors like strain rate/load rate and battery cell type. In the finite element method (FEM) analysis, the mechanical response is investigated in two stages. First, a viscoplastic model is developed in Abaqus/Standard to predict the indentation test. Subsequently, a thermomechanical model is formulated to predict the high-speed-impact penetration test. Considering the high plastic strain rate of the LIB cell, adiabatic heating effects are incorporated into this model, eliminating heat conduction between elements. Addressing a notable discrepancy from prior research, this work explores the substantial reduction in force observed when transitioning from a single cell to a stack of two cells. The study aims to unveil the underlying reasons and provide insights into the mechanical behavior of stacked cells.

A Comprehensive Review of Functional Gel Polymer Electrolytes and Applications in Lithium-Ion Battery.

The rapid expansion of flexible and wearable electronics has necessitated a focus on ensuring their safety and operational reliability. Gel polymer electrolytes (GPEs) have become preferred alternatives to traditional liquid electrolytes, offering enhanced safety features and adaptability to the design requirements of flexible lithium-ion batteries. This review provides a comprehensive and critical overview of recent advancements in GPE technology, highlighting significant improvements in its physicochemical properties, which contribute to superior long-term cycling stability and high-rate capacity compared with traditional organic liquid electrolytes. Special attention is given to the development of smart GPEs endowed with advanced functionalities such as self-protection, thermotolerance, and self-healing properties, which further enhance battery safety and reliability. This review also critically examines the application of GPEs in high-energy cathode materials, including lithium nickel cobalt manganese (NCM), lithium nickel cobalt aluminum (NCA), and thermally stable lithium iron phosphate (LiFePO4). Despite the advancements, several challenges in GPE development remain unresolved, such as improving ionic conductivity at low temperatures and ensuring mechanical integrity and interfacial compatibility. This review concludes by outlining future research directions and the remaining technical hurdles, providing valuable insights to guide ongoing and future efforts in the field of GPEs for lithium-ion batteries, with a particular emphasis on applications in high-energy and thermally stable cathodes.

State-of-health estimation for lithium-ion batteries based on Kullback–Leibler divergence and a retentive network

Accurate state-of-health (SOH) estimation is crucial for the lithium-ion battery industry, as it underpins the safety, durability, and reliability of lithium-ion batteries. Currently, most researchers use various methods of health indicator (HI) extraction for the SOH estimation of batteries. However, these methods may require certain expertise and prior knowledge to achieve accurate modeling, being affected by measurement noise and other factors. To solve the abovementioned problems, three Kullback–Leibler (KL) divergence features based on partial voltage sequences are proposed as new HIs that are independent of prior knowledge and strongly correlated with SOH. Moreover, a modified retentive network is proposed to enhance SOH estimation accuracy and better utilize HIs than traditional deep learning methods, which have high training costs and insufficient accuracy. To ensure consistent extraction of KL divergence features across various experimental conditions and time intervals, a B-spline algorithm is utilized for interpolation. The effectiveness of the proposed method is validated through analysis of Pearson correlation coefficients and experiments conducted in four dimensions. Additionally, the potential of using the proposed method to compress data on the cloud-side is explored.