Battery Thermal Management Research Articles

Comparing different battery thermal management systems for suppressing thermal runaway propagation

Thermal runaway (TR) stands as a critical risk in battery applications. Even though various battery thermal management systems (BTMSs) have been proposed to mitigate thermal runaway propagation, a comprehensive comparison remains elusive. This study evaluates the performance of three types of BTMSs with 5 configurations, which include: liquid cooling with cold plates added on the bottom (BTMS-1a), liquid cooling with cold plates added on the sides (BTMS-1b), liquid cooling with cold plates added between batteries (BTMS-1c), integrating thermal insulation materials between batteries (BTMS-2), and implementing phase change materials between batteries (BTMS-3). The highest temperature, propagation time, temperature uniformity, cooling rate, mass energy density, and volume energy density are used as key performance indicators for comparison. In general, BTMS-2 and BTMS-3 show advantages in energy density, however, their performances on TR suppression and battery thermal management are poor. BTMS-1c can suppress TR effectively at high flowrates, whereas it can lead to poor temperature uniformity. Suggestions are also provided regarding the selection of BTMSs for different applications: BTMS-1b, BTMS-1c, and BTMS-3 are recommended for small EVs, large EVs and large scale battery energy storage systems (BESSs), and small BESSs, respectively.

Thermal management optimization strategy for lithium-ion battery based on phase change material and fractal fin

In order to solve the problem of temperature control of lithium-ion battery (LB) in electric vehicles, a new battery thermal management system (BTMS) based on phase change material (PCM) coupled fractal fin (FF) was proposed. The effects of latent heat, thickness, and thermal conductivity of PCM (paraffin) on the thermal properties of BTMS were investigated. Subsequently, the fin structure was added to the BTMS to improve the heat transfer capacity, and the number of fins, aspect ratio, material and structure morphology were explored. The results show that when the latent heat of PCM is 200 kJ/kg, the thickness is 2 cm, and the thermal conductivity is 0.8 W/(m·K), the temperature of LB is 34.9 K lower than that of LB without the BTMS at 4C. In addition, the BTMS has the best performance when FF-II with a fin count of 5, aspect ratio of 7:1, and material of carbon steel are used. The temperatures of LB are 301.8 K, 303.9 K, 305.4 K, and 307.3 K at 1 to 4C, respectively, and the temperature difference in BTMS can be controlled within 2.5 K. This study provides some guidance for the optimization of BTMS.

Thermal management of lithium-ion batteries based on the coupling of liquid cooling and composite phase change materials

ABSTRACT Effective thermal management techniques for lithium-ion batteries are crucial to ensure their optimal efficiency. This paper proposes a thermal management system that combines liquid cooling with composite phase change materials (PCM) to enhance the cooling performance of these lithium-ion batteries. A numerical study was conducted to examine the impact of various factors on the battery module’s thermal management performance, including the number of flow channels, the distance between these flow channels and the upper and front surfaces, fluid flow rate, coolant inlet temperature, and material’s phase change temperature. The simulation results indicate that at a discharge rate of 6C and a flow channel count of 5, the maximum temperature and the maximum temperature difference of the battery module decrease by 6.44% and 34.35%, respectively, when PCM is coupled with liquid cooling, compared to the pure liquid cooling. However, as the flow rate increases, the rate of temperature reduction slows down, while the pressure drop increases. When the flow rate reaches 0.4 m/s, the maximum temperature only drops by 0.57°C while the pressure drop increases by nearly two times. Furthermore, an increase in the PCM’s melting temperature leads to a larger maximum temperature difference in the battery module. This effect is more pronounced with higher coolant inlet temperatures. Therefore, careful consideration of both flow rate and coolant inlet temperature is essential for designing an effective thermal management system for batteries.

Core-Shell Engineered Fillers Overcome the Electrical-Thermal Conductance Trade-Off.

The rapid development of modern electronic devices increasingly requires thermal management materials with controllable electrical properties, ranging from conductive and dielectric to insulating, to meet the needs of diverse applications. However, highly thermally conductive materials usually have a high electrical conductivity. Intrinsically highly thermally conductive, but electrically insulating materials are still limited to a few kinds of materials. To overcome the electrical-thermal conductance trade-off, here, we report a facile Pechini-based method to prepare multiple core (metal)/shell (metal oxide) engineered fillers, such as aluminum-oxide-coated and beryllium-oxide-coated Ag microspheres. In contrast to the previous in situ growth method which mainly focused on small-sized spheres with specific coating materials, our method combined with ultrafast joule heating treatment is more versatile and robust for varied-sized, especially large-sized core-shell fillers. Through size compounding, the as-synthesized core-shell-filled epoxy composites exhibit high isotropic thermal conductivity (∼3.8 W m-1 K-1) while maintaining high electrical resistivity (∼1012 Ω cm) and good flowability, showing better heat dissipation properties than commercial thermally conductive packaging materials. The successful preparation of these core-shell fillers endows thermally conductive composites with controlled electrical properties for emerging electronic package applications, as demonstrated in circuit board and battery thermal management.

An experimental and comparative study on passive and active PCM cooling of a battery with/out copper mesh and investigation of PCM mixtures

The carbon emission contribution to global warming accelerated both research on and transition to electric vehicles (EVs). Drivers demand high power, fast acceleration and less charging times. All these demands require high C rate charging/discharging demands from batteries. The rate of heat generation is exponentially proportional to C rates which decreases battery lifetime and may lead to thermal runaway. However, a battery thermal management system decreases thermal runaway risk and decelerates battery degradation via controlling battery temperature. In this paper, we first document the thermal conductivity enhancement via copper foam into phase change material (PCM) domain to uncover their possible use in EV thermal management applications. Maximum 15.93 times increment is achieved with a specific copper foam. Then, physical properties and behaviors of distinct PCM mixtures are documented. Homogeneity of mixtures is associated with the chemistry of PCMs and the mixture melting point is proportional to the volume weighted average of melting temperatures. The results document that the PCM with relatively lower melting point is beneficial when end of discharge temperatures considered, except for high discharge rate of 2C. Temperature uniformity across the battery increases with relatively higher melting point PCM. Experiments also document that the amount of PCM volume lost via insertion of copper foam yields higher end of discharge temperatures. Overall, both PCM and copper foam enhances temperature homogeneity and their benefit becomes more sensible during drive cycles relative to continuous charge/discharge use cases.

Computer Aided Analysis of Phase Change Material [PCM] Based Battery Thermal Management System

Computer Aided Analysis of Phase Change Material [PCM] Based Battery Thermal Management System

Numerical Analysis of a Two-Layer PCM Based Battery Thermal Management System for Different Material Properties

The design and numerical analysis of the two-layer PCM (Phase Change Material)-based thermal management system for a 18650-type lithium-ion battery have been performed. In relation to simulation, the coefficient of thermal conductivity and melting temperature of the first layer of PCMs are varied. Other parameters are made identical to that of the next layer's parameters in order that the generation of two different layers of PCMs can be attained: PCM-1 and PCM-2. To obtain a more realistic approach in the numerical analysis, the battery thermal model was created in the COMSOL-MATLAB interface using the experimental internal resistance data obtained for 18650 type Li-ion batteries in the literature. While a cheaper and more accessible material with a thermal conductivity of 0.2 W/mK and a melting point of 50 °C was used in the PCM-2 layer, the thermal conductivity was changed to 0.2; 1 and 5 W/mK in the PCM-1 layer; and the melting point was changed to 30, 40 and 50 °C. In this way, for PCM layers with different thickness (tpcm), the system was optimized at two different discharge rates, 5C and 7C. As a result of the numerical analysis, it was determined that the optimum tpcm, kpcm,1 and Tm values for the 5C discharge rate were 2 mm, 0.2 W/mK and 40 °C, respectively; and the optimum tpcm, kpcm,1 and Tm values for the 7C discharge rate were 4 mm, 5 W/mK and 40 °C, respectively.

Enhanced Thermal Conductivity and Stability of Hydrated Salt Phase Change Microcapsules With GO/SiO2 Hybrid Shell for Battery Thermal Management

AbstractHerein, the synthesis of a novel microencapsulated phase change material via a sol–gel method is presented, featuring disodium hydrogen phosphate dodecahydrate as the core and a SiO2/graphene oxide composite as the shell. The morphology and core–shell microstructure of the synthesized microcapsules are characterized using scanning electron microscopy. The phase change performance and thermal stability are evaluated by differential scanning calorimetry and a high/low temperature test chamber, respectively. Energy dispersive X‐ray spectroscopy and Fourier transform infrared spectroscopy are employed to determine the chemical composition of the microcapsules. The findings reveal that the MEPCM exhibited a high melting enthalpy of 174.3 J g−1. The degree of supercooling is reduced by 2.1 °C, and after 600 thermal cycles, the phase change enthalpy of the microcapsules showed a minor decrease of ≈6.0%. Notably, the thermal conductivity of the microcapsules is significantly enhanced, increasing by up to 51.8%. When integrated into the thermal management systems of lithium‐ion batteries, the MEPCM effectively maintained the battery temperature below 46 °C under a 3 C charging rate. In summary, these results suggest that the hydrated salt microcapsule with its hybrid silica and graphene oxide shell is a promising material for the thermal management of lithium‐ion batteries.

A Review on Advanced Battery Thermal Management Systems for Fast Charging in Electric Vehicles

To protect the environment and reduce dependence on fossil fuels, the world is shifting towards electric vehicles (EVs) as a sustainable solution. The development of fast charging technologies for EVs to reduce charging time and increase operating range is essential to replace traditional internal combustion engine (ICE) vehicles. Lithium-ion batteries (LIBs) are efficient energy storage systems in EVs. However, the efficiency of LIBs depends significantly on their working temperature range. However, the huge amount of heat generated during fast charging increases battery temperature uncontrollably and may lead to thermal runaway, which poses serious hazards during the operation of EVs. In addition, fast charging with high current accelerates battery aging and seriously reduces battery capacity. Therefore, an effective and advanced battery thermal management system (BTMS) is essential to ensure the performance, lifetime, and safety of LIBs, particularly under extreme charging conditions. In this perspective, the current review presents the state-of-the-art thermal management strategies for LIBs during fast charging. The serious thermal problems owing to heat generated during fast charging and its impacts on LIBs are discussed. The core part of this review presents advanced cooling strategies such as indirect liquid cooling, immersion cooling, and hybrid cooling for the thermal management of batteries during fast charging based on recently published research studies in the period of 2019–2024 (5 years). Finally, the key findings and potential directions for next-generation BTMSs toward fast charging are proposed. This review offers an in-depth analysis by providing recommendations and potential solutions to develop reliable and efficient BTMSs for LIBs during fast charging.

Modelling Analysis of Propylene Glycol as a Cooling Media for Battery Thermal Management System in Electric Vehicles

Modelling Analysis of Propylene Glycol as a Cooling Media for Battery Thermal Management System in Electric Vehicles

Cooling Performance of a Nano Phase Change Material Emulsions-Based Liquid Cooling Battery Thermal Management System for High-Capacity Square Lithium-Ion Batteries

This study investigated the application of nanophase change material emulsions (NPCMEs) for thermal management in high-capacity ternary lithium-ion batteries. We formulated an NPCME of n-octadecane (n-OD) and n-eicosane (n-E) with a mass fraction of 10%, whose phase change temperatures are 25.5 °C and 32.5 °C, respectively, with specific heat capacities 2.1 and 2.4 times greater than water. Experiments were conducted to evaluate the thermal control performance and latent heat utilization efficiency of these NPCMEs. The NPCMEs with an n-OD mass fraction of 10% (NPCME-n-OD), particularly reduced the battery pack’s maximum temperature and temperature difference to 41.6 °C and 3.72 °C under a 2 C discharge rate, lower than the water-cooled group by 1.3 °C and 0.3 °C. This suggests that nano emulsions with phase change temperatures close to ambient temperatures exhibit superior cooling performance. Increased flow rates from 50 mL/min to 75 mL/min significantly lowered temperatures, resulting in temperature reductions of 2.73 °C for the NPCME-n-OD group and 3.37 °C for the NPCME-n-E group. However, the latent heat utilization efficiency of the nano emulsions decreased, leading to increased system energy consumption. Also, it was found that the inlet temperature of the NPCMEs was very important for good thermal management. The right inlet temperatures make it easier to use phase change latent heat, while excessively high temperatures may make thermal management less effective.

A Battery Thermal Management System Integrating Immersion Preheating and Immersion Cooling

A Battery Thermal Management System Integrating Immersion Preheating and Immersion Cooling

An Investigation into the Viability of Cell-Level Temperature Control in Lithium-Ion Battery Packs

Abstract This article focuses on the thermal management and temperature balancing of lithium-ion battery packs. As society transitions to relying more heavily on renewable energy, the need for energy storage rises considerably, as storage facilitates power regulation between these sources and the grid. Lithium-ion batteries are leading the market for energy storage options, but their properties are temperature sensitive, with thermal abuse resulting in shortened pack lifetime and possible safety issues. Current battery thermal management systems (BTMS) are implemented in a number of ways to ensure consistent and reliable operation. However, they are typically limited in architecture and restricted in ability to attend to temperature gradients. This work proposes a BTMS topology that permits control of the individual cooling received by a cell in a pack. First, an analysis is done using timescale separation to confirm that cell-level temperature control is capable of extending the lifetime of a pack as compared to pack-level control. The analysis is used to guide the gain tuning of a state feedback controller, which directs more cooling effort to cells of higher temperatures. Validation of the BTMS topology and control is performed through the simulation of a battery pack, with variations in total cooling power and resistance heterogeneity. The outcome of the validation studies indicates that the proposed BTMS configuration is better equipped to reduce temperature differences and extend pack life. This benefit increases as total input power increases, giving the controller more freedom to cool unhealthy cells while remaining within power constraints.

Boron nitride: The key material in polymer composites for electromobility

AbstractDespite the continuous development and improvement of many technologies and multifunctional materials for the electric powertrain (ePowertrain) for electric vehicles, there are still technical issues and challenges to address such as thermal management in batteries, electric motors, and power electronic devices, as most of their failures are due to poor thermal management. Consequently, conventional engineering polymer materials already used must be replaced since most of them have low thermal conductivity and are therefore limited in performance for thermal management applications. A key solution is to develop highly thermally conductive polymer composites that combine other features, such as flame‐retardant, electrical insulation, and mechanical and barrier properties, by incorporating fillers into the polymer matrix. This approach has attracted intensive research efforts. In this review, we first examine the key drivers, trends, and solutions of the ePowertrain segment, emphasizing thermal management. Second, special attention is given to the state‐of‐the‐art boron nitride (BN) polymer composites with current or potential applications in the automotive industry, especially, in batteries, electric motors, and power electronics. Third, analysis and prediction of thermal properties of BN polymer composites by finite element simulation are presented. Finally, outlooks for future research in this field are highlighted.Highlights Thermal management of batteries, electric motors and power electronics, using BN polymer composites, optimizes the functionality of electric vehicles. Cross‐linked polymers with BNNSs provide resins for high power motors, film capacitors, and Li‐metal battery electrolytes for electric vehicles. Mathematical modeling and life cycle analysis can predict trends and research gaps in ePowertrain applications.

A Novel Paraffin Wax/Expanded Graphite/Bacterial Cellulose Powder Phase Change Materials for the Dependable Battery Safety Management

Although phase change materials (PCMs) exhibit effective performance in the thermal management of lithium-ion batteries (LIBs), their development is limited by low thermal conductivity and susceptibility to leakage during the solid–liquid phase transition. To address these challenges and enhance thermal management capabilities, this study introduces a novel composite phase change material (CPCM) synthesized by physically mixing paraffin (PA), expanded graphite (EG), and bacterial cellulose (BC). The thermal performance of CPCMs with varying BC proportions is evaluated, and their impact on temperature control in battery thermal management systems (BTMS) is assessed. The results show that the addition of EG and BC significantly improves the thermal conductivity of the CPCM, reaching a value of 1.39 W·m−1·K−1. This also enhances the uniformity of temperature distribution within the battery module and reduces CPCM leakage. By comparing temperature variations within the battery module under different operating conditions, it was found that the intricate network structure of the CPCM promotes uniform temperature distribution, effectively mitigating temperature rise. Consequently, the maximum temperature and maximum temperature difference within the battery module were maintained below 47 °C and 4 °C, respectively. Compared to a system without phase change material at a 3C discharge rate, the maximum cell temperature, maximum module temperature, and maximum temperature difference were reduced by 32.38%, 26.92%, and 34.94%, respectively. These findings provide valuable insights for the design and optimization of BTMS.

Simulation and Experimental Study on Heat Transfer Performance of Bionic Structure-Based Battery Liquid Cooling Plate

This study presents a bionic structure-based liquid cooling plate designed to address the heat generation characteristics of prismatic lithium-ion batteries. The size of the lithium-ion battery is 148 mm × 26 mm × 97 mm, the positive pole size is 20 mm × 20 mm × 3 mm, and the negative pole size is 22 mm × 20 mm × 3 mm. Experimental testing of the Li-ion battery’s heat generation model parameters, in conjunction with bionic structure and micro-channel features, has led to the development of this innovative cooling system. The traditional bionic liquid cooling plate’s structure is often singular; however, the flow path of the liquid cooling plate designed in this paper is based on the combination of the distribution of human blood vessel branches and the structure of insect wing veins. The external dimension of the liquid cooling plate is 152 mm × 100 mm × 6 mm (length × width × height). Utilizing numerical simulation and thermodynamic principles, we analyzed the heat transfer efficacy of the bionic liquid cooling module for power batteries. Specifically, we investigated the impact of varying coolant flow rates and the contact radius between flow channels on the thermal performance of the bionic battery modules. Our findings indicate that a liquid flow rate of 0.6 m/s achieves a stable maximum surface temperature and temperature differential across the bionic battery liquid cooling module, with a relatively low overall system power consumption, suggesting room for further enhancement of heat transfer performance. By augmenting the contact radius between flow channels, we observed an initial increase in the maximum surface temperature, temperature differential, and inlet–outlet pressure differential at a flow rate of 0.2 m/s. However, at flow rates equal to or exceeding 0.4 m/s, these parameters stabilized across different design Scenarios. Notably, the pump power consumption remained consistent across various scenarios and flow rates. This study’s outcomes offer valuable insights for the development of liquid-cooled battery thermal management systems that are energy-efficient and offer superior heat transfer capabilities.

Electric Vehicle Energy Management via Traffic Light Detection and Segmental Velocity Forecasting

Abstract Predictive-based power control has been widely recognized as a promising approach to boost driving range and improve system-level energy efficiency for electric vehicles (EVs), in which vehicle velocity forecasting generally serves as a preliminary input to optimally schedule the operations of varying on-board electrical and thermal systems. A segment-based velocity forecasting approach for individual commuting vehicles developed in this study reveals that it is challenging to forecast the velocity at intersection segments only using the velocity data. To address this challenge, this study seeks to develop a YOLO-V2-based object detection deep network to recognize the traffic lights in advance, and leverage the detected signals to establish a forecasting model that integrates with the probability-based hybrid forecasting approach. The case study results show that the traffic light detection-based forecasting model can significantly improve the forecasting accuracy for intersection segments. Based on the forecasting velocity 5-15 seconds ahead, the effectiveness of model predictive control-based energy management strategy is further evaluated with a liquid-based battery thermal control system. The proposed Battery Thermal Management System (BTMS) model shows promising results in maintaining battery temperature within an appropriate range, thus improving the overall energy efficiency of the EV. Moreover, a traffic light-based real-time energy management framework is developed to directly control the power demand from the Air Conditioning (AC) system.

A liquid-cooled plate based on bionic flow channels evolved from the shape of leaf veins and tree roots

With the rapid development of lithium-ion (Li-ion) batteries, battery thermal management (BTMS) is increasingly essential for the temperature control of Li-ion batteries. The energy required to control temperature is coming into focus. In order to consume less energy to control temperature and improve temperature uniformity, the liquid-cooled plate (LCP) based on bionic flow channels evolved from the shape of leaf veins and tree roots is proposed. In this BLCP, different from the others BLCPs, it is divided into a reinforced heat exchange area located in the middle and back part of the plate and a normal area located in the front part of the plate. Firstly, 16 sets of orthogonal tests are conducted based on four parameters: the distance of the hexagon from the outlet (a), the distance from the inlet (b), the distance between two adjacent hexagons (c) and the size of the hexagon (d). Secondly, Optimization was investigated based on NSGA-II for two objectives: temperature and pressure drop. The simulation results are analyzed based on the optimized structural parameters (a = 30 mm, b = 8 mm, c = 50 mm and d = 90 mm). After Comparing the optimization results with the simulation results, the temperature and pressure drop errors were 0.56 percent and 3.8 percent, respectively. The effects of flow rate and thickness of the fluid domain on temperature and pressure drop are next discussed separately. Finally, after comparing the optimized bionic liquid cooling plate (BLCP) with the conventional liquid cooling plate (CLCP) based on temperature pressure drop, velocity, and synergy angle, conclusions are made at the same inlet width, height, flow rate, and velocity (V = 0.2 m/s). This leads to the criterion of energy loss becoming only the pressure drop. The BLCP for pressure drop is 14.2 percent lower than the CLCP, which means less energy loss. The maximum temperature of the BLCP is 0.7 °C lower than that of the CLCP. Furthermore, the former has a better ability to suppress the rate of temperature rise and better temperature uniformity. In addition, this proposed new structure and research methods can be applied to the subsequent study of LCP.

A Novel Electric Vehicle Thermal Management System Based on Charging Station Heat Pump System During Fast Charging

Abstract A battery thermal management system based on a charging station heat pump system is proposed to improve battery charging efficiency during high-power DC charging. The system provides coolant of appropriate temperature through the charging station heat pump system. It enables the battery to be charged at the optimal temperature for charging, which improves the charging efficiency and reduces the charging time. The two system models are modeled and analyzed using numerical simulation software, and the temperature characteristics and charging time of the proposed system and the original battery thermal management system based on the electric vehicle heat pump system are analyzed under five different temperature conditions. The results show that the proposed system has fast response, high efficiency, and can maintain the maximum temperature below 50°C. Compared with the original system, the proposed system reduces the charging time of the power battery by 10.6%, 17.9%, and 24.6% at 0°C, −10°C, and −20°C operating conditions, respectively. It also saves 1.4% and 6.0% of the charging time at 20°C and 40°C operating conditions, respectively. Comparing the charging time for the power battery at each stage, the proposed system mainly reduces the charging time in the range of 0-20% of the battery state of charge compared to the original system.

Numerical and artificial neural network inspired study on step-like-plenum battery thermal management system

This study leverage numerical simulation (NS) and artificial neural network (ANN) capabilities to carry out additional investigations on step-like plenum battery thermal management system (BTMS). Different cooling strategies have been developed over the years in BTMSs’ design. Yet, air-cooling strategies still remains relevant, especially in battery-powered aircrafts, where light-weight is important and air is the preferred cooling fluid. Hence, additional study become necessary especially on the step-like plenum design to provide more insight on the performance of the design by considering several number of step, varied air inlet temperature and velocity. Computational fluid dynamics (CFD) approach was employed to obtained results for different number of step; Ns = 1, 3, 4, 7, 9, 15 and 19, varied air inlet temperature; Ti = 278, 298 and 318 K, and varied air inlet velocity; Vi = 3, 3.5, 4, 5 and 6 m/s. Artificial Neural Network (ANN) approach was then employed to predict the BTMSs’ performance for additional values of Ti and Vi. Minimum temperature (Tmin), maximum temperature (Tmax), maximum temperature difference (ΔTmax) and pressure drop (ΔP) were computed. By comparing the CFD results with the result predicted by the ANN, the percentage difference, for the entire dataset were 0.01 %, 0.005 %, 1 % and 0.14 % for Tmax, Tmin ΔTmax and ΔP, respectively. Based on the optimum design parameters predicted using ANN, for Tmax = 299.24 comprises Ns = 4, Vi = 6 m/s and Ti = 278 K, while for ΔP, comprises Ns = 1, Vi = 3 m/s and Ti = 318 K.