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In advanced battery thermal management systems for electric vehicles, liquid cooling (LC) is typically coupled with a phase-change material (PCM) cooling for secondary heat dissipation. However, a continuous LC consumes a considerable amount of energy without considering the operating conditions. In this study, the thermal behaviors of tubular PCMs were examined under different liquid temperatures (25, 45, and 65 °C) to simulate the complex operating conditions of battery modules. In addition, a thermal management module coupling the PCM and copper pipe (CP) with LC was assembled to enhance the secondary heat dissipation of PCM cooling, particularly in a high-temperature environment. The experimental results confirmed the superior cooling effect of the PCM–CP module, even at high temperatures. Moreover, a dynamic LC (DLC) mode was proposed to reduce the energy consumption caused by LC, where LC operates intermittently. The effects of the LC activation time on the cooling behavior were explored. A coefficient illustrating the energy efficiency ratio (EER) was defined to evaluate the cooling performance and energy consumption of the two DLC modes with varying working times. The results proved that DLC-2 performed better than DLC-1 with E E R ¯ j values of 0.35 and 0.24, respectively. These results are expected to provide insights into the development of advanced energy-saving thermal management systems. [Display omitted] [ABSTRACT FROM AUTHOR]

The demand for high energy density in lithium-ion battery packs for electric vehicles poses a challenge to maintaining its optimum operating temperature while reducing the risk of thermal runaway (TR) propagation. This study proposes a novel hybrid TR propagation mitigation system that balances heat transfer and thermal insulation requirements using low and high thermal conductivity phase change materials (PCM), heat pipes (HP), and air-cooling. The design and optimization of such a mitigation system are complex due to the many design parameters involved. The Adaptive-Kriging-High dimensional model representation (Adaptive-Kriging-HDMR) is used to establish a surrogate model of the system, and the sensitivity of the system's design parameters is evaluated with the maximum battery temperature and the system weight as the targets, thereby improving the efficiency of model calculation and reducing the dimension of optimization parameters. Then, the design of the sensitive parameters is optimized using an extended elitist non‐dominated sorting genetic algorithm (E-NSGA-II) multi-objective optimization algorithm. The results show that the modeling difficulty and optimization calculation time are significantly reduced by using a surrogate model. The calculation time for a single surrogate model only takes a few seconds instead of several hours for the original three-dimensional heat transfer and flow calculation. The thermal conductivity of high thermal conductivity-PCM, the distance between battery and low thermal conductivity-PCM, the battery spacing, and the HP length significantly affect the system. The optimized system substantially reduces the overall weight of the battery system while ensuring its good heat dissipation capability. In the case of TR in a single battery, the system succeeds in limiting the TR propagation to the same row, with the maximum battery temperature in the second row being only 64.3 °C, well below the battery TR trigger point. Under more severe conditions, such as TR occurring in two batteries simultaneously, the maximum battery temperature in the second row is 155.5 °C, and no TR spreads to the adjacent row. This study provides a rapid and effective method for designing a TR propagation mitigation system. It can serve as a reference for the engineering design and optimization of battery thermal management systems. [ABSTRACT FROM AUTHOR]

To ensure the optimal operating temperature of lithium-ion batteries, a novel thermoelectric-based battery thermal management system coupled with water cooling and air cooling is proposed in this work. Also, a hydraulic-thermal-electric multiphysics model is established to assess the system's thermal behavior. Through numerical simulations, the effect of different cooling parameters, including TEC (thermoelectric cooler) input current, air convection heat transfer coefficient, and cooling water flow rate on thermal performance is comprehensively analyzed. The results show that the introduction of thermoelectric cooling into battery thermal management can amplify the cooling ability of traditional air cooling and water cooling, and the cooling power and COP (coefficient of performance) of thermoelectric coolers first increase and then decrease with the increase of input current. Under the air convection heat transfer coefficient of 50 W m−2 K−1, water flow rate of 0.11 m/s, and TEC input current of 5 A, the battery thermal management system reaches the optimal thermal performance, corresponding to the maximum temperature and temperature difference of 302.27 K and 3.63 K respectively. However, the cooling parameters of these three factors interact with each other, and it is vital to select appropriate cooling parameters to balance the thermal performance and energy consumption of the battery thermal management system. More importantly, this work provides a brand-new idea for the thermal management of batteries. [ABSTRACT FROM AUTHOR]

In the work, a composite cooling system coupled with PCM (phase change material) and liquid cooling was designed. The influence of parameters such as spacing, EG (expanded graphite) content, battery direction, coolant flow rate and pipe diameter on the cooling performance was analyzed. The results revealed that: (1) The increase of spacing makes the temperature of the pack decrease, but the effect degree of increasing the spacing on temperature performance decreases when the spacing exceeds 14 mm. At the same time, CPCM formed by the added high thermal conductivity material expanded graphite and paraffin can effectively improve the temperature control performance of the pack, which can control the temperature at 313.15K under the condition of an ambient temperature of 308.15K (2) By comparing the maximum temperature and the temperature difference of the pack under different discharge methods, it is concluded that the poles facing inward can reduce the accumulation of the interior heat. (3) The convective heat transfer coefficient and Nu number of the pack are increasing as the flow rate increases, but the slope of the temperature versus flow rate decreasing slowly. After increasing the inlet size, the inner wall surface area of the pipe increases and the average convective heat transfer coefficient of the pack reduces. However, the Nu number increases with the increase of the pipe diameter, indicating that the growth of the pipe diameter can enhance the heat transfer rate. (4) Orthogonal experiment and fuzzy correlation analysis were combined to analyze the parameters that affect the thermal performance of the BTMS. It was determined that using a proper coolant flow rate can maximize the thermal performance of the pack. • A composite cooling system coupled with PCM and liquid cooling is designed. • Influences of the key parameters on the cooling performance are analyzed. • Orthogonal experiment and fuzzy correlation analysis are used to analyze affecting parameters. • Some results for enhancing cooling performance are obtained. [ABSTRACT FROM AUTHOR]

To enhance the cooling and preheating performance of the battery, a novel hybrid battery thermal management system (BTMS) containing bionic spiral fins wrapped with phase change material (PCM) and embedded liquid cooling is proposed. The cylindrical battery is strategically positioned on a spiral fin, the heat of the battery and PCM is transferred to the cold plate through the extended winglets. The thickness (L 1), height (L 2), distance (L 3) and number of winding turns (N) of fin are optimized using the response surface method (RSM). The effects of the liquid cooling duration, flow rate, channel shape and direction of the flow channel on the latent heat recovery of PCM and the cooling performance of the battery module are analyzed. The results demonstrated that at the duration of 600 s and flow rate of 0.09 g/s, the liquid fraction of PCM reduced from 57 % to 26 %. Furthermore, the preheating efficiency of the BTMS was investigated under different parameter configuration and boundary conditions. The preheating temperature increased by 5.6 °C compared with the BTMS without fins. Additionally, the temperature difference (ΔT) of the BTMS with Layout 2 decreases by 0.5 °C compared with 4.1 °C of Layout 1 at flow rate of 0.5 g/s. [ABSTRACT FROM AUTHOR]

Pursuing high cooling-preheating performances of integrated battery thermal management system (BTMS) inevitably complicates the module structure, leading to great decreases in energy densities. To unblock this trade-off relationship, we propose a compact and lightweight integrated-BTMS by introducing bi-functional heating-cooling plates (BF-HCPs) and temperature-equalizing strategies based on differentiated inlet velocities (v I and v II) and heating powers (P I and P II). Firstly, the skillful design of BF-HCPs simplifies the structure of BTMS by reducing individual heating/cooling accessories. Subsequently, multi-objective optimization of v I , v II , P I , P II and channel width ratio (WR) realizes temperature equalization in large modules. The optimal WR locates at 0.60–0.65; differentiated v I and v II is fixed at large values of 0.25 and 0.16 m·s−1, respectively; the total P I + P II is preferably larger than 695 W with a narrow P II / P I of 0.53–0.56. Consequently, the obtained BTMSs demonstrate outstanding comprehensive performances. In cooling mode, the maximum temperature and temperature difference can be controlled below 30 and 3 °C at 4-C discharge. In preheating mode, the preheating time is lower than 500 s with a temperature difference < 3 °C. Furthermore, the obtained battery module possesses higher energy densities of 143.6 Wh·kg−1 and 332.2 Wh·L−1 than the reported battery modules with existing integrated BTMSs. [ABSTRACT FROM AUTHOR]

The phase change immigration of flame retardant Composite Phase Change Material (CPCM), especially the temperature aging effect during multicycle process, greatly restricted its application in power battery pack of electric vehicle and energy storage system. In this study, the properties of flexible flame-retardant CPCMs before and after temperature aging were investigated, and the battery thermal management effects of battery modules were compared. The results revealed that flexible CPCMs with styrene block copolymers exhibited little volume change owing to their elastic and anti-leakage properties, effectively alleviating flow and agglomeration. In addition, battery modules with flexible flame-retardant CPCMs exhibited prominent battery thermal management. These mechanisms in flame-retardant CPCMs can profoundly affect the design and preparation of multifunction CPCMs, providing novel insights into passive thermal management of battery systems. [ABSTRACT FROM AUTHOR]

The phase change immigration of flame retardant Composite Phase Change Material (CPCM), especially the temperature aging effect during multicycle process, greatly restricted its application in power battery pack of electric vehicle and energy storage system. In this study, the properties of flexible flame-retardant CPCMs before and after temperature aging were investigated, and the battery thermal management effects of battery modules were compared. The results revealed that flexible CPCMs with styrene block copolymers exhibited little volume change owing to their elastic and anti-leakage properties, effectively alleviating flow and agglomeration. In addition, battery modules with flexible flame-retardant CPCMs exhibited prominent battery thermal management. These mechanisms in flame-retardant CPCMs can profoundly affect the design and preparation of multifunction CPCMs, providing novel insights into passive thermal management of battery systems. [ABSTRACT FROM AUTHOR]

Pursuing high cooling-preheating performances of integrated battery thermal management system (BTMS) inevitably complicates the module structure, leading to great decreases in energy densities. To unblock this trade-off relationship, we propose a compact and lightweight integrated-BTMS by introducing bi-functional heating-cooling plates (BF-HCPs) and temperature-equalizing strategies based on differentiated inlet velocities (v I and v II) and heating powers (P I and P II). Firstly, the skillful design of BF-HCPs simplifies the structure of BTMS by reducing individual heating/cooling accessories. Subsequently, multi-objective optimization of v I , v II , P I , P II and channel width ratio (WR) realizes temperature equalization in large modules. The optimal WR locates at 0.60–0.65; differentiated v I and v II is fixed at large values of 0.25 and 0.16 m·s−1, respectively; the total P I + P II is preferably larger than 695 W with a narrow P II / P I of 0.53–0.56. Consequently, the obtained BTMSs demonstrate outstanding comprehensive performances. In cooling mode, the maximum temperature and temperature difference can be controlled below 30 and 3 °C at 4-C discharge. In preheating mode, the preheating time is lower than 500 s with a temperature difference < 3 °C. Furthermore, the obtained battery module possesses higher energy densities of 143.6 Wh·kg−1 and 332.2 Wh·L−1 than the reported battery modules with existing integrated BTMSs. [ABSTRACT FROM AUTHOR]