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The frequent occurrence of thermal runaway accidents of lithium-ion batteries has seriously hindered their large-scale application in new energy vehicles and energy storage power plants. Careful analysis of lithium-ion batteries can essentially determine the cause of the accident and then reduce the likelihood of lithium-ion battery thermal runaway accidents. However, there are few current studies on lithium-ion battery accident investigation, and the destruction of traces due to the violent reaction of the battery's thermal runaway increases the difficulty of battery accident investigation. The thermal runaway accident scenarios of lithium-ion batteries with different states of charge will show different regular characteristics of the thermal runaway properties and trace characteristics of lithium-ion batteries. Establishing the relationship between the thermal runaway characteristics of lithium-ion batteries, the trace law and the state of charge can effectively improve the technology of in-depth battery accident investigation. This study investigated the thermal runaway and trace characteristics of lithium-ion batteries triggered by nail penetrating at different states of charge using 8 Ah soft pack lithium iron phosphate batteries as the research object. The results show that lithium iron phosphate Li-ion batteries do not trigger thermal runaway under nail penetrating conditions when the state of charge is less than 20%, with no obvious phenomena and slight changes in the voltage and surface temperature of the battery, with the temperature only rising by 5 ℃. Both the 60% and 100% SOC LiFePO4 batteries underwent thermal runaway within a few seconds after the needle puncture and produced a large amount of white smoke, with the voltage rapidly dropping to 0 V and the maximum temperature on the front of the battery reached 93 ℃ and 125 ℃, respectively, and the rate of temperature rise was significantly higher in the latter than in the former, with both reaching temperatures above 200 ℃ at the penetration point and higher than at the entry point, while the 100% SOC battery showed electrical sparks and more smoke after the puncture due to a more violent internal short-circuit. The state of charge affects the cracks and particle spacing on the surface of the anode electrode and the smoothness of the surface. The results of this paper provide ideas for qualitative and quantitative analysis of lithium-ion battery accident causation, which can provide guidance for effectively improving the ability to investigate lithium-ion battery accidents. [ABSTRACT FROM AUTHOR]

NiS/Ni@HCNF electrode enable the cell with excellent storage capacity and superior thermal safety performance. [Display omitted] • Catalytic chemistry inspired hollow carbon nanofibers loaded with NiS/Ni is designed. • Such delicate structure shows superior cycling and rate property than many TMSs. • The favorable Li+ storage actions and related reaction kinetics are discovered. • Using the designed structure markedly promotes the thermal safety of LIBs. Transition metal sulfides (TMSs) based anodes hold a very broad application prospect in lithium ion batteries (LIBs). In this work, the catalytic effect of metallic nickel at high temperature was used to generate hollow carbon nanofibers loaded with NiS and Ni (denoted as NiS/Ni@HCNF). The heteroatoms doped carbon fibers buffer the huge volumetric change of NiS during the discharge/charge process, and enhance the ion transport efficiency and electrical conductivity. In addition, the high specific surface area brought by the hollow carbon nanofibers can accelerate the electrolyte penetration and speed up the transport of ions as well as electrons. When used as anode of half cell, this electrode gives 958.5 and 612.9 mAh/g after running 1000 cycles under 1 and 2 A/g, showing the extremely-low attenuation rates of 0.0483 % per cycle and 0.0643 % per cycle, respectively. Impressively, NCM//NiS/Ni@HCNF battery shows the discharge capacity of 187.6 mAh/g at 1st cycle. Regarding the next 100 cycles, the relatively-high discharge capacities (>110 mAh/g) and coulombic efficiency (CE) values (>96 %) are discerned. It is noted that the usage of NiS/Ni@HCNF electrode improves the activation energy for thermal runaway, corroborating the elevated thermal safety of battery. [ABSTRACT FROM AUTHOR]

This paper provides insights into the four key behaviors and mechanisms of the aging to failure of batteries in micro-overcharge cycles at different temperatures, as well as the changes in thermal stability. The test results from a scanning electron microscope (SEM) and an energy-dispersive spectrometer (EDS) indicate that battery failure is primarily associated with the rupture of cathode materials, the fracturing and pulverization of electrode materials on the anode current collector, and the formation of lithium dendrites. Additionally, battery safety is influenced by environmental temperatures and the battery's state of health (SOH), with failed batteries exhibiting the poorest stability and the highest mass loss rates. Under isothermal conditions, micro-overcharge leads to battery failure without thermal runaway. Thus, temperature stands out as the most influential factor in battery safety. These insights hold significant theoretical and practical value for the development of more precise and secure battery management systems. [ABSTRACT FROM AUTHOR]

Lithium battery temperatures will increase if the heat produced during the charging and discharging procedures is not promptly vented externally. Fewer investigations have been conducted on materials that can retain good flexibility at room temperature and shape stability at high temperatures under the existing thermal management system for phase change materials (PCM). In this study, a particular kind of flexible composite PCM (CPCM) at room temperature is created to address the issue of heat transfer between the PCM and the power battery. The characteristics of hardness, room-temperature flexibility, form stability at high temperature, and thermal conductivity are compared with those of three other thermally induced flexible CPCMs. The flexibility at room temperature of the new CPCM is demonstrated by the results, which makes assembly easier and helps further lower the contact thermal resistance. Charge–discharge test comparisons of the battery modules employing the chosen CPCM and thermally induced CPCM are performed to further evaluate their thermal management capabilities. The thermally induced CPCM exhibits larger maximum temperature profiles at the discharge rates of 1C, 2C, and 3C than the room-temperature flexible CPCM. The variations in maximum temperatures are 0.96, 1.48, and 2.08 °C. [ABSTRACT FROM AUTHOR]

The operation of solid-state Li batteries, which are promising power supplies for portable electronic devices and electric vehicles, is accompanied by heating. Therefore, investigating the thermal stability of battery systems is essential. In this study, we report the impact of annealing on the interface of a Li3PO4 electrolyte and LiNi0.5Mn1.5O4 electrode in thin-film batteries. The batteries with the interface annealed at 200 °C show low Li3PO4–LiNi0.5Mn1.5O4 interface resistance of 7.2 Ω cm2. Furthermore, the batteries exhibit stable charge–discharge characteristics with high current density up to 1170 μA cm−2, similar to those of batteries with the non-annealing interface. The batteries with the interface annealed at 450 °C show high Li3PO4–LiNi0.5Mn1.5O4 interface resistance of 490 Ω cm2, resulting in low battery performance. X-ray photoemission spectroscopy indicates that the P in Li3PO4 is reduced by high-temperature annealing, possibly causing the performance degradation of batteries. This study provides an in-depth understanding of the interfaces of solid-state batteries and is expected to facilitate the development of thermally stable batteries. [ABSTRACT FROM AUTHOR]

The temperature and temperature differences in the battery module rise as a result of the high heat output produced by lithium-ion batteries during operation. This can reduce the operating safety of the battery and reduce the battery life. As a result, the temperature of the batteries must be controlled well by thermal management. Thermal control of batteries employs both active and passive techniques. In this study, PCM, which is a passive cooling system, was used. It has been observed that by placing PCM around the battery, it effectively reduces the peak temperature during the end of discharge in the battery cell. The RT-27 and nano-doped RT-27 with suitable melting range were used as PCM. Four different situations were investigated at 0.3C and 0.5C discharge conditions. These are battery models coated with only the battery, RT-27, coated with nano-RT-27, and coated with RT-27 and nano-RT-27, respectively. The peak temperature was found to be higher when the battery module without PCM was compared to the others. The battery module coated on both surfaces with RT-27 and nano-RT-27 performed better than the other modules. At 0.3 C-Rate, the peak temperature reduces by 1.8 K while it is 4.4 K at 0.5C-Rate. [ABSTRACT FROM AUTHOR]

Most battery cells are developed according to a standard design and optimized regarding their electrical properties. However, firstly, there is a demand for an individual cell design adapted to the application. Secondly, additional properties, for example, thermal and mechanical, are decisive for the cell behavior and should be considered in the overall design. Therefore, the present work introduces a model-based development tool for the holistic design of format-flexible battery cells, which are optimized for their future application, allowing for different cell geometries within one battery system. The different approaches and simulation models for the single design steps are presented, and the prediction of the electrochemical, electrical, and thermal behaviors of the cell and whole battery system is described. A key aspect here is the appropriate interconnection of the single models in a way that helps to narrow down the multitude of interacting parameters in a systematic manner and, thus, makes a holistic design possible. In a last step, the functionality of the tool is shown in a case study by means of an e-bike battery pack. [ABSTRACT FROM AUTHOR]

This study aims to improve the performance of automotive battery thermal management systems (BTMS) to achieve more efficient heat dissipation and thus reduce hazards during driving. Firstly, the research parameters and properties of composite thermally conductive silicone materials are introduced. Secondly, the heating principle of the power battery, the structure and working principle of the new energy vehicle battery, and the related thermal management scheme are discussed. Finally, the research results are presented from the experimental test and controller design. In addition, to achieve the research goal, the composite thermally conductive silica gel plate (CSGP) material is studied in detail and parametrically analyzed, and the heating mechanism of the power battery is discussed in depth. The temperature characteristics after adding CSGP are experimentally tested, and the controller of the BTMS of the new energy vehicle is designed, including hardware circuits and software modules. The findings show that the temperature characteristics of the battery module have obvious limitations without CSGP. When the battery module operates at a 4C magnification, the temperature exceeds the safety threshold by 38.4%, with particular potential safety risks. Then, the maximum temperature of the battery module with CSGP can be controlled within 50 °C, and the temperature characteristics are prominently improved. Lastly, the controller of the BTMS is tested, and the results reveal that it has remarkable voltage recovery ability. According to the research results, the performance of automotive BTMS can be significantly improved, and better heat dissipation can be effectively achieved by adding CSGP. This helps reduce the hazards of driving. Moreover, the designed controller performs well in voltage recovery, providing solid theoretical support for further developing the CSGP battery management system. [ABSTRACT FROM AUTHOR]

The electrical performance of lithium-ion battery gradually deteriorates with the temperature decrease. Alternating current (AC) heating is an efficient manner to improve the lithium-ion battery (LIB) discharge ability at low temperature. This paper proposes an effective method to quickly preheat battery under low temperature based on sinusoidal AC. An electrothermal coupled model is established to precisely characterize the battery electrical and thermal behavior characteristics. Subsequently, the impedance characteristics of large format prismatic LIB are investigated through electrochemical impedance spectroscopy testing. The amplitude and frequency of sine wave current exploited for battery pack heating are optimized at different temperatures and SOC based on the analysis of AC impedance. Finally, the sinusoidal AC heating for battery pack is achieved leveraging the designed full bridge inverter circuit-based heater and the heating efficiency with respect to different amplitudes and frequencies are comprehensively compared. On this basis, a frequency varying heating strategy with fixed amplitude considering the current limitation of hardware circuit is proposed. The experimental results show that the battery pack can be rapidly heated from −30 °C to 0 °C with the maximum average temperature rise rate of 3.78 °C/min, and the heating energy consumption rate is less than 0.27% SOC/°C with the proposed strategy. On this account, the battery pack discharge capacity under frigid environment can be distinctly enhanced based on the proposed heating strategy. • The impedance characteristics are comprehensively investigated based on EIS. • A precise electrothermal coupled model is built to imitate LIB thermal behavior. • The heating strategy with fixed amplitude and varying frequency of AC is proposed. • The hardware of full bridge inverter circuit-based heater is carefully designed. • Battery pack is rapidly heated with heating rate of 3.78 °C/min at −30 °C temperature. [ABSTRACT FROM AUTHOR]

• The coating layer of carbon was designed for a bare CuF 2 cathode. • The carbon layer inhibits side reactions between CuF 2 and LiF–LiCl–LiBr electrolyte. • CuF 2 @C delivers ultrahigh discharge specific capacity and actual discharge time. Conversion-type compounds as cathodes for thermal batteries have recently attracted considerable attention due to their excellent specific capacities. CuF 2 has been regarded as a promising candidate owing to its high theoretical discharge voltage (3.55 V, vs Li) and theoretical capacity (528 mAh·g−1). However, mass loss caused by side-reactions from CuF 2 cathode and molten salt electrolyte leads to severe degradation of the discharge capacity of single-cells in thermal batteries. As a proof-of-concept, in this work, carbon coated CuF 2 (CuF 2 @C) is employed as the cathode to fabricate thermal batteries, in which carbon serves as a protector to inhibit the mass loss of CuF 2 in molten salt electrolyte. As a result, CuF 2 @C demonstrates obviously improved electrochemical performance with a discharge specific capacity of 462.45 mAh·g−1 at the current density of 10 mA·cm−2, which is 82.67 % higher than that of the counterpart (bare CuF 2). This can be attributed to the reduced average polarization resistance of the single-cells in CuF 2 @C composites. This work provides a new route for developing high performance CuF 2 -based cathode material for thermal batteries and promoting its further practical application. [ABSTRACT FROM AUTHOR]

• Three layout schemes of liquid cooling plate were discussed. • The heat dissipation in a liquid cooling system was considered under various factors. • The heat dissipation scheme for imported coolant cooling of variable temperature was proposed. • The solution reduces the temperature difference of the battery pack by 36.09 %. To promote energy conservation and emission reduction, the electric vehicles (EVs) are developing rapidly. An effective battery thermal management system (BTMS) can extend the service life of batteries and avoid thermal runaway. In this study, a liquid-cooling management system of a Li-ion battery (LIB) pack (Ni-Co-Mn, NCM) is established by CFD simulation. The effects of liquid-cooling plate connections, coolant inlet temperature, and ambient temperature on thermal performance of battery pack are studied under different layouts of the liquid-cooling plate. Then, A new heat dissipation scheme, variable temperature cooling of the inlet coolant, is proposed. Results indicate that connecting two sets of liquid coolant plates in a 3-series, 1-parallel configuration can effectively reduce the maximum temperature of the battery pack from 48.73 ℃ to 30.75 ℃, while controlling the maximum temperature difference to 3.98 ℃ at the end of discharge. Simultaneously, the proposed cooling scheme reduces the maximum temperature difference within the battery pack by 36.09 % at the beginning of the discharge period. This study provides a valuable reference into advancing BTMSs of battery pack-level for EVs. [ABSTRACT FROM AUTHOR]

• Pulsating heat pipes with good thermal performance were designed for battery module heating management at low–temperatures. • The low–temperatures thermal management system for the battery module with pulsating heat pipes was proposed. • The thermal and electrical performance of the battery module with low–temperatures thermal management system was investigated. To effectively solve the problem that the capacity of lithium power batteries decreases significantly and is prone to irreversible damage under low–temperature charge and discharge scenarios, which seriously affects the driving range, cycle life and service safety of electric vehicles (EVs). In this paper, a low–temperatures thermal management system of pulsating heat pipes with ethanol as the base fluids and TiO 2 nanofluids as the working fluids (TiO 2 –CLPHP TMS) is constructed. On this basis, the thermal performance analysis of TiO 2 nanofluids pulsating heat pipes (TiO 2 –CLPHP) is carried out under different volume concentrations (0 %, 0.5 %, 1.0 %, 2.0 %, 4.0 %, and 8.0 %) and different fluid filling rates (30 %, 50 %, 70 %, and 90 %) in a low–temperature environment. Aiming at the low–temperatures charging scenario of the battery module, the performance test of the TiO 2 –CLPHP TMS for the battery module heating management is carried out under different low–temperature environments (−5 °C, −15 °C, and −25 °C) and different charging rates (0.3C, 0.5C, 0.7C, and 1.0C). The experimental results show that TiO 2 –CLPHP with fluids filling rate of 50.00 % and TiO 2 nanofluids concentration of 2.00 % has good performance in start–up and heat transfer, and can optimize the thermal performance of TiO 2 –CLPHP. Meanwhile, TiO 2 –CLPHP TMS can ensure that the battery module has superior thermal performance. the battery module can be charged within the allowed temperature range (greater than 0 °C). under different low temperature environments (−5 °C, −15 °C, and −25 °C), the temperature of the battery module is basically maintained at 3.30 °C, 8.00 °C and 16.00 °C. The temperature difference between different areas of the battery module is within the allowable temperature difference range of 5 °C, which reduces the adverse effects of the battery aging caused by low–temperature charging and uneven temperature. Moreover, the battery module also has good electrical performance, the battery module voltage is in a low–level range in the early and middle stages of charging. During the complete charging process, the low–temperature charging capacity of the battery module has almost no attenuation, and the charging capacity ratio is as high as 95.92 %. Compared with the pure battery module, the charging capacity and charging efficiency of the battery module with the TiO 2 -CLPHP TMS has been improved to different degrees. Especially at −25 °C, the maximum charging capacity and charging efficiency can be increased to 24.51 %, and the minimum can be increased to 13.17 %. which ensures the efficient charging of the battery module. This proves that the designed TiO 2 –CLPHP TMS is feasible and effective for battery module heating management. [ABSTRACT FROM AUTHOR]

To maintain the optimal battery performance, it is essential to develop an efficient battery thermal management system for keeping the battery operation temperature within the appropriate range. In this work, a novel design of cold plate featuring airfoil fin channel is developed as a highly effective cooling module of a prismatic LiFePO 4 battery pack. The thermal performance of battery and the thermo-hydraulic performance of the cooling module for the cold plate featuring airfoil fin channel, U-type channel and serpentine channel are numerically investigated and compared to reveal the superiority of the novel cold plate. The results indicate that compared with the U-type channel and the serpentine channel, the airfoil fin channel can enhance the total heat dissipation amount by 3.47% and 4.64%, respectively. Besides, the airfoil fin channel can provide the smallest battery maximum temperature and temperature difference under the same coolant flow rate. The airfoil fin channel provides the smallest pressure loss and heat transfer coefficient but the largest overall thermo-hydraulic performance indictor in terms of j / f factor. Under the same requirement of battery cooling performance, the remarkably smaller power consumption is required for the airfoil fin channel compared with the U-type channel and serpentine channel. • A novel cold plate with airfoil fins is designed for cooling battery. • Performance of airfoil fin cold plate and two conventional cold plates is compared. • Airfoil fin cold plate is of the largest heat dissipation capacity. • Airfoil fin cold plate is of the best overall performance. [ABSTRACT FROM AUTHOR]

There is a pressing requirement to design a simple battery thermal model that balances simulation accuracy regarding battery thermal characteristics and engineering application feasibility. The paper carries out the experimental study and model characterization of thermoelectric coupling characteristics of ternary lithium batteries with different shapes under ambient temperature conditions. The paper designs a characterization method of the battery thermoelectric coupling model. It conducts experiments to analyze the battery's charging and discharging characteristics and extracts essential modeling parameters. It reveals the differences in the modeling parameters of ternary lithium batteries with different shapes and constructs the thermoelectric coupling models of the square and 21700 cylindrical ternary lithium battery respectively. At the same time, the paper applies the model to carry out the simulation and experimental verification of the battery thermal behavior. The experimental data monitored by the infrared thermal imager and temperature sensors are compared with the simulation results. The errors are less than 5 %. It can provide a reference for related researches and engineering applications of battery thermal behavior and thermal management. • Designing a model characterization method for batteries with different shapes. • Revealing differences in modeling parameters of batteries with different shapes. • Constructing a simpler battery thermal model with low calculation volume. • Balancing the accuracy of simulation with the feasibility of applications. [ABSTRACT FROM AUTHOR]

Lithium-ion battery heating technology is a crucial enabler for electric vehicles to operate in cold climates. Ensuring the delicate balance between temperature rise rate and temperature uniformity faces unprecedented challenges due to the poor thermal diffusivity of batteries. In order to overcome the challenges, first of all, this study proposes a sandwich self-heating structure for lithium-ion batteries and establishes a temperature uniformity model during the heating process of sandwich self-heating structure batteries. Then, the effects of duty cycle on temperature uniformity and heating rate are analyzed. Finally, a rapid warm-up strategy considering temperature uniformity is proposed to reconcile the contradiction between heating rate and temperature uniformity. The proposed rapid warm-up strategy can shorten the heating time by 16 % under three typical heating scenarios. Furthermore, the proposed strategy is applied to two other sandwich self-heating structures with different batteries, and the results show that the rapid warm-up strategy can significantly reduce the heating time and has the potential to be promoted in different types of batteries. • A temperature uniformity model for sandwich self-heating structure. • A rapid warm-up strategy considering temperature uniformity. • Proposed strategy shortens heating time by up to 17 % under three typical scenarios. • The proposed superior strategy is also applicable to other batteries. [ABSTRACT FROM AUTHOR]

• Developed and analyzed a novel hybrid battery pack thermal management system. • Incorporated a novel three-stage cooling strategy into the thermal management system. • Latent heat of PCM effectively extracts heat from the cylindrical Li-ion cells. • Secondary coolants increase the overall heat transfer coefficient of PCM. This paper introduces a novel hybrid thermal management concept, which use secondary coolants (air and water) to extract heat from a phase change material (paraffin), resulting in increased heat extraction capability of the paraffin and improvement the overall thermal performance of the battery module. This concept was analyzed using experimental and numerical studies. The experimental studies were conducted to obtain the temperature and heat flux profiles of the battery module. The numerical model is developed and validated using the experimental data obtained. The outcome of the study showed that the battery module temperature reached the phase change temperature threshold of the PCM in the fifth discharge cycle, and the through the use of latent heat the battery module temperature was maintained between 42 and 44 °C. Additionally, the thermal uniformity started to increase once the PCM started to change and the PCM utilization was ∼2.3 % after seven discharge cycles. Therefore, the proposed thermal management concept for the battery module can sustain the thermal environment needed for effective operation of the Lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Indiscriminate use of lithium battery packs will produce gases called thermal runaway gases, the most important of which are CO, CO 2 , and H 2. Doping transition metals on the MoSe 2 surface can effectively improve the gas detection effect of the substrate, and the application of transition metal clusters can further affect the adsorption process. In this study, transition metal Cu n and Pd n (n=1–3) are used to modify the MoSe 2 substrate to detect the target gases, The process is as follows: [Display omitted] • Different from previous single transition metal and metal oxide modifications, this paper proposes metal cluster modified MoSe 2 substrate. The Cu and Pd are selected as modified metals, and the maximum number of clusters is three. • The improvement effect of Cu n and Pd n (n = 1–3) clusters on the MoSe 2 substrate is obtained through the analysis of binding energy, bandgap, DOS and charge transfer, and the conductivity of the MoSe 2 substrate has been improved. • The adsorption process of thermal runaway gases on six modified substrates is considered. The adsorption performance of the target gases on five modified substrates is ranked as follows: CO>H 2 >CO 2. However, the adsorption effect of CO 2 on the Cu 3 -MoSe 2 substrate is better than that of H 2. • The analysis of molecular orbitals, work functions and sensitivity further verified the roles of Cu n and Pd n (n = 1–3) in detecting thermal runaway gases. The manuscript mainly explores the adsorption behavior and related parameters of Cu n and Pd n (n = 1–3) clusters modified MoSe 2 substrates for thermal runaway gases (CO, CO 2 , H 2) in lithium batteries by DFT. The modified structures are analyzed through E b , band structure, Q t , and DCD. Compared with the MoSe 2 bandgap (1.710 eV), Cu n and Pd n (n = 1–3) clusters modifications reduce the bandgap and become more compact. During the modification process, the metal clusters acquire electrons from the substrate and change the DOS of the substrate. The metal clusters improve the conductivity of the substrate. The adsorption and sensing properties between target gases and the substrates through the analysis of the E d , Q t , DCD, and DOS. The adsorption capacity of target gases on Cu-MoSe 2 , Pd-MoSe 2 , Cu 2 -MoSe 2 , Pd 2 -MoSe 2 , and Pd 3 -MoSe 2 substrates is ranked as follows: CO > H 2 > CO 2. The adsorption effect of Cu 3 -MoS 2 substrate on target gases is ranked as follows: CO > CO 2 > H 2. Analysis of molecular orbitals, work functions, and sensitivity can describe the adsorption effect of the substrates on the target gases. The results provide a theoretical basis for the development of gas sensors for detecting the operating status of lithium batteries. [ABSTRACT FROM AUTHOR]

• Form-stable and flame-retardant CPCM is produced for battery thermal safety management. • The optimum mass ratio of the CPCM is obtained by comprehensive analysis. • CPCM has a positive effect on battery heat absorption and increasing the time between the thermal runaway spread. Phase change materials (PCMs), characterized by zero energy consumption and high energy storage density capability, have a wide range of applications. However, the development of organic PCM is restricted by their low thermal conductivity, easy leakage and high combustibility. In this study, we produced a composite phase change materials (CPCM) with both high thermal conductivity and flame-retardant effect for application in battery thermal safety management. We demonstrated that addition of a porous network structure of EG as a shaping support to increase PA's thermal conductivity, and incorporation of environmentally safe and non-toxic silica-based flame retardant (SiO 2 sol) improved the flame retardant properties. The optimum mass ratio of the CPCM was obtained by comprehensive analysis of the shape and thermal stability, energy storage performance and thermal conductivity. It was also verified by cone calorimetry that the CPCM outperformed pure PA in several aspects: heat release, smoke release rate and emission of toxic gases. The cooling and thermal runaway experiment of the battery module showed that the addition of CPCM had a positive effect on absorption of battery heat and extending the time between the thermal runaway spread of battery modules (21 s increasing to 396 s), providing valuable time for the safe evacuation of people in the event of a runaway fire. [ABSTRACT FROM AUTHOR]

• Various approaches to modeling the thermal behavior of batteries are reviewed with regard to thermal coupled battery models for the thermal analysis of battery and battery thermal management system (BTMS). • Three commonly used battery models for thermal-coupled simulations, simple battery model, electrical circuit model (ECM), and physics-based electrochemical model are reviewed. • The methods of the parameter identification for the thermal-coupled battery modeling are also introduced. • The merits and drawbacks of each model are discussed in detail, and the complexities involved in parameter identification are investigated. • The objective of this extensive review is to assist researchers and engineers in choosing and effectively employing suitable tools for the investigation of battery thermal management. With the increasing popularity of electric vehicles, there is a growing need for efficient and reliable thermal management systems to regulate the temperatures of lithium-ion batteries. Heat generation, which can lead to decreased performance, reduced lifespan, and even safety hazards if not properly managed, is a major challenge for these batteries. This review provides an overview of the numerical modeling techniques used to simulate heat generation and thermal management in lithium-ion batteries for electric vehicles. Various approaches to modeling the thermal behavior of batteries are reviewed with regard to thermal coupled battery models for the thermal analysis of battery and battery thermal management system (BTMS). This review discusses various modeling approaches, including simple battery models, electrical circuit models (ECMs), and physics-based electrochemical models, focusing on the Newman P2D model. Thermal runaway model that is employed to inform safety design for lithium-ion battery is also reviewed. In addition, the parameter identification methods for these models are reviewed. The merits and drawbacks of each model are discussed in detail, and the complexities involved in parameter identification are investigated. This comprehensive review aims to guide researchers and engineers in selecting and utilizing appropriate tools for battery thermal management studies. [ABSTRACT FROM AUTHOR]

• Secondary flow was introduced to improve the performance of serpentine channel BTMS. • A grid + elliptical groove serpentine channel plate is proposed in this paper. • Pump power is reduced by 92.6 % and cooling efficiency coefficient is increased by 11.097 times. • Clear the coolant flow trajectory and eddies distribution. • Sensitivity analysis to further clarify the mechanism of cooling. To improve the thermal and economic performance of liquid cooling plate for lithium battery module in the distributed energy storage systems, on the basis of the traditional serpentine liquid cooling plate, the unidirectional secondary channels and grooves are added, combined to three kinds of serpentine cold plates for the battery module. By contrast, the cold plate with both elliptical groove and secondary channel has the best comprehensive performance. Though the thermal performance is slightly reduced, the consumption of pump power is reduced by 92.6 % and the cooling efficiency coefficient is improved by 12.32 times compared to the original cold plate. The cooling temperature targets of the battery pack are that T max less than 40℃ and Δ T avg less than 3 K. In order to achieving the best performance of the cold plate, the influence of the structural parameters and hydrodynamic parameters on the performance index is analyzed, and the sensitivity analysis is carried out which clear the operational mechanism and key design parameters of the cold plate. The results show that different design parameters would generate the change of eddy current which is influential to the cooling performance. Besides, v and D have a significant effect on the performance of the cold plate, followed by d and n, and a has almost no effect on the cooling performance. [ABSTRACT FROM AUTHOR]

Increasing charging rate is an upgrading direction of electrochemical energy storage, which might induce more heat accumulation, posing a higher risk to cause the battery thermal runaway (TR). Driven by this, an experimental investigation was carried out to study the characteristics of TR and gas venting behaviors in commercial lithium iron phosphate (LFP) batteries that were induced by overcharging under different rates. As the charging rate increases, the growth rate of lithium dendrites accelerates, resulting in the earlier formation of large-scale short circuits and a rapid transition to the next stage of the TR chain reaction. However, the temperature rise and the total heat does not increase in proportion to the charge rates. The electrolyte also accelerates its decomposition, and the reaction between the electrolyte and lithium is the main reason of overcharge heat accumulation. It is worth noting that the charging rate for overcharging is positively correlated with the TR violence of batteries and the explosion risk of the ejected gas. The main gases emitted are H 2 , CO, and CO 2 and various alkanes. Specifically, the content of H 2 gas increases significantly with the increase of charging rate. And the H 2 contents for 2C, 1.5C and 1C correspond to 61%, 53% and 50%, respectively. The rapid growth of lithium dendrites results in a significant increase in H 2 generation and earlier capture. This is accompanied by a higher impact pressure and a lower explosion limit (LEL) of the combustible gas mixture, indicating a severer explosion risk. In short, by comparing the TR characteristics and gas products of LFP batteries with different charging rates, which is of great significance for the fire extinguishing design and emergency response of energy storage systems. [ABSTRACT FROM AUTHOR]