Battery Thermal Management System Research Articles

Expression of concern for article entitled “Numerical analysis of pressure drop and heat transfer of a non-Newtonian nanofluids in a Li-ion battery thermal management system (BTMS) using bionic geometries”

Expression of concern for article entitled “Numerical analysis of pressure drop and heat transfer of a non-Newtonian nanofluids in a Li-ion battery thermal management system (BTMS) using bionic geometries”

Analysis and design of module-level liquid cooling system for rectangular Li-ion batteries

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.

Design and Implement a BTMS using Phase Change Material - A Review

Abstract: This paper presents a comprehensive review of the design and implementation of Battery Thermal Management Systems (BTMS) utilizing Phase Change Materials (PCM). The thermal management of batteries is crucial for ensuring optimal performance, safety, and longevity, particularly in electric vehicles and renewable energy storage applications. Phase change materials offer unique advantages for thermal management, including high latent heat storage capacity, thermal conductivity, and temperature regulation capabilities. This review discusses the fundamentals of PCM-based BTMS design, including PCM selection, integration methods, and system optimization techniques. Additionally, recent advancements, challenges, and future directions in PCM-based BTMS are explored, providing valuable insights for researchers, engineers, and industry practitioners in the field of energy storage systems.

Experimental exploration of nano-phase change material composites for thermal management in Lithium-ion batteries

The present study reports an experimental investigation carried out for the thermal management of cylindrical lithium-ion battery simulator using aluminium oxide (nano particle)-eicosane (phase change material) composites. The experiment involves varying the power input from 4 to 10 W in 2 W increments and adjusting the weight percentage of nanoparticles (wt %) from 0.5 to 0.9 in 0.2 wt % intervals. The examination of battery temperature evolutions in response to heating power, a comprehensive heat transfer analysis incorporating Nusselt number, determination of maximum temperature difference, thermal resistance analysis, and exploration of temperature variations in the absence of Phase Change Material (PCM) are considered. The results show that increase in weight percentage of alumina nanoparticles in phase change material cannot always improve the thermal performance. The results of the present study give a guideline for designing battery thermal management system. The power levels used in the experiment vary from 4 W to 10 W in steps of 2 W. For a power level of 4 W, the heat flux is 1.088 kW/m2, and for a power level of 10 W, the heat flux is 2.72 kW/m2.

Minimum Air Cooling Requirements for Different Lithium-ion Battery Operating Statuses

Abstract Batteries play an important role in increasing the use of renewable energy sources. Owing to the temperature sensitivity of lithium-ion batteries (LIBs), battery thermal management systems (BTMSs) are crucial to ensuring the safe and efficient operation of LIBs. Researchers have mainly focused on evaluating the performance of BTMS; however, little attention has been paid to the minimum cooling requirements of LIBs, which are important for optimizing the design and operation of BTMSs. To bridge this knowledge gap, the aim in this study was to determine the minimum air cooling requirements for different LIBs operating statuses based on computational fluid dynamics simulations. The inlet airflow rate had the strongest influence. For the studied cases, when the battery operates at charge/discharge (C) rate of three or below, the inlet temperature should be set below 35 °C, and the gap between the batteries should be greater than 3 mm to meet the minimum heat dissipation requirement. At a C-rate of 0.5C, natural convection is sufficient to meet the cooling needs, whereas at 1C or higher rates, forced convection is required. Increasing the number of batteries from six to eight has little impact on the inlet flow required to accommodate the battery heat dissipation.

Improving heat transfer in indirect liquid-based battery thermal management systems through turbulator-equipped conical flow paths

To guarantee the safe operation of Li-Ion Cells (LICs) in various applications, such as electric vehicles, an efficient Battery Thermal Management System (BTMS) is necessary. The design of BTMSs, as documented in the literature, typically involves the use of cooling channels with uniform and smooth configurations. However, these configurations encounter the challenge of temperature non-uniformity in the battery module, which stems from elevated coolant temperatures along the flow direction. In this study, a 3D numerical analysis is conducted to develop a novel indirect liquid-based cooling system for the BTMS of a module with cylindrical LICs. The study explores the effects of conical cooling channels, both with and without twisted turbulators, across various coolant mass flows during a 2C discharge process of LICs. Within the studied ranges, diverging cooling channels improve the overall thermal and hydraulic performance of the BTMS by an average of 40%, increasing the heat transfer coefficient by a maximum of 32.6%, and decreasing pressure drop by up to 35.1%. The application of turbulators proves effective in reducing the maximum temperature difference within the LICs, demonstrating a decrease of approximately 34.2% at the minimum mass flow rate and 74.4% at the maximum mass flow rate. This emphasizes the more substantial impact of turbulator utilization at higher coolant mass flow rates. An increased coolant flow rate leads to a significant enhancement of the heat transfer coefficient, ranging from 70.5% to 79.0% for the BTMS incorporating turbulators. Moreover, the study highlights a more pronounced impact of increasing mass flow rates in the BTMS designed with converging cooling channels compared to those designed with diverging channels. Finally, the results of this analysis demonstrate that the proposed system is capable of efficiently regulating the temperature of the entire battery module, ensuring that it consistently maintains a normal and safe operational range suitable for vehicular applications (below 40 °C).

Multi-Strategical Thermal Management Approach for Lithium-Ion Batteries: Combining Forced Convection, Mist Cooling, Air Flow Improvisers and Additives

Maintaining the peak temperature of a battery within limits is a mandate for the safer operation of electric vehicles. In two-wheeler electric vehicles, the options available for the battery thermal management system are minuscule due to the restrictions imposed by factors like weight, cost, availability, performance, and load. In this study, a multi-strategical cooling approach of forced convection and mist cooling over a single-cell 21,700 lithium-ion battery working under the condition of 4C is proposed. The chosen levels for air velocities (10, 15, 20 and 25 m/s) imitate real-world riding conditions, and for mist cooling implementation, injection pressure with three levels (3, 7 and 14 bar) is considered. The ANSYS fluent simulation is carried out using the volume of fluid in the discrete phase modelling transition using water mist as a working fluid. Initial breakup is considered for more accurate calculations. The battery’s state of health (SOH) is determined using PYTHON by adopting the Newton–Raphson estimation. The maximum temperature reduction potential by employing an airflow improviser (AFI) and additives (Tween 80, 1-heptanol, APG0810, Tween 20 and FS3100) is also explored. The simulation results revealed that an additional reduction of about 11% was possible by incorporating additives and AFI in the multi-strategical approach. The corresponding SOH improvement was about 2%. When the electric two-wheeler operated under 4C, the optimal condition (Max. SOH and Min. peak cell temp.) was achieved at an air velocity of 25 m/s, injection pressure of 7 bar with AFI and 3% (by wt.) Tween 80 and a 0.1% deformer.

Efficient Design of Battery Thermal Management Systems for Improving Cooling Performance and Reducing Pressure Drop

The air-cooled system is one of the most widely used battery thermal management systems (BTMSs) for the safety of electric vehicles. In this study, an efficient design of air-cooled BTMSs is proposed for improving cooling performance and reducing pressure drop. Combining with a numerical calculation method, a strategy with a varied step length of adjustments (∆d) is developed to optimize the spacing distribution among battery cells for temperature uniformity improvement. The optimization results indicate that the developed strategy reduces the optimization time by about 50% compared with a strategy using identical ∆d values while maintaining good performance of the optimized system. Furthermore, the system’s pressure drop does not increase after the spacing optimization. Based on this characteristic, a structural design strategy is proposed to improve the cooling performance and reduce the pressure drop simultaneously. First, the appropriate flow pattern is arranged and the secondary outlet is added to reduce the pressure drop of the system. The results show that the BTMS with U-type flow combined with a secondary outlet against the original outlet can effectively reduce the pressure drop of the system. Subsequently, this BTMS is further improved using the developed cell spacing optimization strategy with varied ∆d values while the pressure drop is fixed. It is found that the final optimized BTMS achieves a battery temperature difference below 1 K for different inlet airflow rates, with the pressure drop being reduced by at least 45% compared with the BTMS before the optimization.

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

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

Performance analysis of a battery thermal management system based on phase change materials with micro heat pipe arrays

Lithium-ion battery packs generate high-level heat under harsh and rigorous conditions. The inadequate heat dissipation results in high pack temperature above the safe operating range. This study investigates an efficient and cost-effective battery thermal management system based on phase change materials and a micro heat pipe array. The battery is treated as a single domain. A battery pack with six series stacked batteries is analyzed using the Newman-Tiedemann-Gu-Kim model. The thermal performance of a battery thermal management system is analyzed using phase change materials with various melting temperature values, ambient temperature, and convective heat transfer coefficients of micro heat pipe arrays. Results show that the maximum temperature of the cooling system with micro heat pipe arrays and phase change materials is 33.8 °C, which is reduced by 22.3 % and 7.8 % compared to the air-cooled and cooling system with micro heat pipe arrays. At forced convection of 50 W·m−2·K−1, the maximum battery temperature values for the phase change material RT31, RT35, and RT42 are reduced by 11.8 %, 8.9 %, and 5.4 % compared to those at forced convection of 5 W·m−2·K−1. Under short-circuit conditions, the cooling system with micro heat pipe arrays and cooling system with micro heat pipe arrays − phase change materials reduce the maximum battery temperature by 12.4 % and 29.9 % compared to the air-cooled system. Results show that the developed model for the battery thermal management system provides a reference for designing phase change materials with micro heat pipe arrays.

Advancements in Battery Thermal Management for High-Energy-Density Lithium-Ion Batteries in Electric Vehicles: A Comprehensive Review

Lithium-ion batteries are frequently utilized in electric vehicles because of their high energy density and prolonged cycle life. Maintaining the right temperature range is crucial since lithium-ion batteries' performance and lifespan are highly sensitive to temperature. This study discusses a practical battery heat control system in this setting. The phenomenon of heat generation and significant thermal problems with lithium-ion batteries are reviewed in this work. The studies on various battery thermal management systems (BTMS) are then thoroughly analysed and arranged into groups based on thermal cycle possibilities. Direct refrigerant two-phase cooling, second-loop liquid cooling, and cabin air cooling are all components of the BTMS. Phase change material cooling, heat pipe cooling, and thermoelectric element cooling are all future parts of the BTMS. The maximum temperature and maximum temperature differential of the batteries are examined for each BTMS, and a suitable BTMS that addresses the drawbacks of each system is discussed. Finally, a novel BTMS is suggested as a practical thermal management solution for lithium-ion batteries with high energy density.

Thermal management system for stable EV battery operation with composite phase change materials

Li-ion battery has been one of the cornerstone of the mobile era especially given the burst sales of Electrical vehicles (EV) which have eclipsed that of internal combustion engine vehicles over last decade. While extensive advances in smart production and technologies make it booming to the development of EV, there have been frequently reported fatal fire incidents originated from excessive thermal hazards of Li-ion batteries. In this paper, we developed a new Li-ion battery thermal management system, by making use of porous Aluminum structure as skeleton and Phase Change Materials (PCMs) as filler, to maintain its optimal operating temperature below 35 °C within a small tolerance range of ± 1 °C fluctuation by continuous heat absorption and heat release during the phase changes of the PCM. The thermal stress and energy consumption in the internal battery pack caused by temperature fluctuations can thus be reduced, ultimately sustaining the overall functional life span of the battery. We envision that our work will advance the operation of EV battery and incubate a versatile framework ranging from thermal management to battery assembly.

BATTERY COOLING SYSTEMS OF ELECTRIC VECHILES

To enhance electric vehicle battery performance, the Battery Thermal Management System (BTMs) plays a crucial role by regulating internal battery temperature within optimal limits. Among the key components, the cooling system is paramount in maintaining this temperature range. Various cooling techniques such as Air Cooling (AC), Liquid Cooling (LC), Refrigerant Direct Cooling (RDC), Phase Change Material (PCM) based systems, Thermoelectric Cooling (TC), Heat Pipe Cooling (HPC), and Hybrid Cooling (HC) have been employed in electric vehicles. This paper provides an exhaustive review of these cooling systems, delineating their respective merits and demerits. The findings offer valuable insights for researchers delving into electric vehicle battery cooling technology. Keywords: Electric vehicle, battery, cooling system, thermal management system.

Thermal performance enhancement with snowflake fins and liquid cooling in PCM-based battery thermal management system at high ambient temperature and high discharge rate

The application of phase change materials (PCMs) in battery thermal management system (BTMS) is restricted by their low thermal conductivity and the challenge of heat-storage saturation after latent heat depletion, particularly in conditions with high ambient temperature and discharge rate. To enhance the performance of thermal management, this study firstly evaluates the thermal behaviors of two designs, Batteries-PCM and Batteries-PCM-Fins, under discharge rates of 3C and 5C, in conjunction with ambient temperatures of 25 °C and 40 °C. Building on this foundation, a hybrid thermal management system that incorporates snowflake fins and liquid cooling is proposed. The cooling efficiency of five different liquid cooling plate configurations (Design I-V) is compared, and the impact of coolant flow rate is explored. The results indicate that the snowflake fins in the Batteries-PCM-Fins design effectively reduce battery temperatures at a 3C discharge rate, maintaining a max temperature difference below 3 °C. However, at a 5C discharge rate and 40 °C ambient temperature, there is a noticeable increase in the peak temperature of the battery module across numerous cycles. Among the tested designs, Design IV shows the best performance. Specifically, when the coolant flow rate is 0.1 m/s, the discharge rate is 5C, and the ambient temperatures are 25 °C and 40 °C, compared to the design lacking a liquid cooling plate, the maximum temperature of the battery module decreases by 17.40 % and 21.36 % respectively, with respective decreases of 42.53 % and 55.77 % in the maximum temperature difference.

Case study on thermal management of planar elements with various polymeric heat exchangers: experiment and simulation

AbstractA reliable battery thermal management system (BTMS) is essential to ensure proper performance, a long life span and high electric vehicle safety. The primary objective of BTMS is to maintain the cells’ temperature in the range of 15–35 °C while limiting the temperature spread between cells to below 5 °C. Active thermal management with polymeric hollow fibers (PHFs) has been reported in a few articles, but its tremendous flexibility is mainly advantageous for cylindrical cells. Extruded polymeric cold plate heat exchangers with rounded rectangle channels (RRCs) are proposed as a more elegant solution for planar batteries. Heat exchangers using PHFs and RRCs were experimentally compared, with a strong focus on minimizing the maximum temperature and temperature spread of the experimental setup while simultaneously achieving minimal pressure drops. The system behavior with different parameters, including materials, geometry and thermophysical properties, was further studied using properly validated CFD models.

Thermal performance analysis of battery thermal management system utilizing bionic liquid cooling plates with differentiated velocity distribution strategy

Bionic channel liquid cooling plates (BC-LCPs) show high heat dissipation performance in battery thermal management system (BTMS), but suffer from the poor temperature-equalizing ability. Herein, a BTMS with novel BC-LCPs and differentiated velocity distribution strategy is proposed to overcome the low temperature uniformity, and balance the cooling performance and power consumption. The BC-LCPs are firstly designed by precisely tailoring the series cobweb channels inspired by the bionic structures in the nature. Through systematic optimization combining single factor analysis with orthogonal test and complementary test, differentiated velocities (vI and vII) of 0.20 and 0.46 m∙s−1 are adopted, respectively. Ultimately, the LC system demonstrates exceptional cooling performance while maintaining lower energy consumption. For example, with a discharge rate of 3C and an environment temperature of 50 °C, the temperature and temperature difference of the battery pack are controlled synergistically below 30.9 and 4.47 °C, respectively. At the same time, the Ptotal can reach as low as 0.202 W, which is reduced by 42.0 % compared to the case with uniform velocity strategy.

Ageing comparison of passive battery thermal management systems: Air cooling and loop heat pipes

Flat plate Loop Heat Pipes (LHPs) have emerged as an attractive battery thermal management system (BTMS) as they allow long-distance heat transfer at no power cost due to their unique porous structure. Additionally, the flat contacting surface is suitable for end cooling in cylindrical cells due to the higher axial thermal conductivity of the jelly roll structure. Previous studies on LHP BTMS have mainly focused on the cooling performance of prismatic or pouch cells, without considering cell ageing. This study instead numerically investigates the cooling performance, the resulting current distribution, and the ageing of a 6S4P 18650 battery module equipped with LHPs BTMS, comparing the performance against a natural air convection BTMS. This study has taken various thicknesses of the heat collector plate (i.e. 0.5 mm, 1 mm, 2 mm and 3 mm) and the number of LHPs (i.e. 1 or 2) into consideration. The results indicate that utilising a single LHP in conjunction with a 2 mm thick heat collector plate emerges as the optimal configuration. This design achieves a maximum average temperature of 29.7 °C and a minimal temperature gradient of 0.02 °C under a 1C discharge condition. The proposed design also significantly enhances battery lifespan, reaching up to 310 cycles with a maximum ageing gradient of 0.005, compared to the 146 cycles and 0.04 ageing gradient observed for the module with natural air convection. This study presents the potential of LHP BTMS for future electric vehicles, demonstrating its superior effectiveness in enhancing battery performance and longevity.

A review on recent progress in battery thermal management system in electric vehicle application

Global challenges of energy crisis and air pollution have presented a tremendous opportunity for the development of electric cars. Li-ion batteries are crucial for electric cars (EVs). Nevertheless, Li-ion batteries are sensitive to the operating temperature and only function optimally within a certain temperature range. Hence, EVs require a battery thermal management system (BTMS). A cooling system's advantage is that it prevents the premature deterioration of battery life. This article examines several battery temperature management techniques and classifies them as either active or passive. In addition, the hybrid BTMS with an active/passive combination is described. This article gives an overview of current advancements in the direction of BTMS with direct and indirect cooling technologies, as well as key insights into hybrid BTMS.

Multi-objective optimization analysis of air-cooled heat dissipation coupled with thermoelectric cooling of battery pack based on orthogonal design

As the energy supply core of electric vehicles (EVs), the battery's performance is closely related to its temperature. Therefore, the battery thermal management system (BTMS) plays a crucial role in ensuring the vehicle's driving safety and power performance. This paper proposes the air cooling as the primary heat dissipation method, combined with a semiconductor refrigeration sheet (SRS) to improve heat transfer and reduce local high temperature. Firstly, determine the optimum air volume with the U-type air-cooled structure. Additionally, orthogonal analysis is used to investigate the inlet and outlet locations, the front deflector position and length of the shunt chamber, and the rear deflector position on the air-cooling effect. Then, through multi-objective optimization, the optimal air-cooled structure is selected based on the air supply pressure drop. The chosen structure is the same-side dual-exit ventilation with a front deflector located 150 mm from the near-wind end wall and a length of 30 mm, and a rear deflector located 100 mm from the far-wind end wall. Finally, SRS coupled air cooling is used to dissipate the heat. Four SRSs are used to analyze the effect of mounting position and different currents on the battery pack. The findings suggest that the optimal placement for SRSs is parallel to the lower end of the battery module at the far-wind end. When SRSs pass a current of up to 0.4A at 37 ℃, the entire battery module can complete 7200 s discharge with 0.5C. This leads to a decrease in the maximum temperature (Tmax) to 46.09 ℃ and a drop in the temperature uniformity index (δT) to 1.36.

Performance enhancement of a battery thermal management system using novel liquid cold plates with micro-channel featuring pin fins

Performance enhancement of a battery thermal management system using novel liquid cold plates with micro-channel featuring pin fins