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The thermal performance of a lithium-ion battery pack for an electric vehicle by adding straight rib turbulators in battery cooling plate channels has been numerically investigated in this paper and the numerical model of the battery pack has been validated by experimental data, which exhibits a satisfactory prediction accuracy. The effects of rib shapes, rib angles, rib spacings, and irregular gradient rib arrangement configurations on the flow and heat transfer behaviors of battery pack cooling plates have been thoroughly explored and analyzed in this paper. In addition, the thermal performance of the ribbed battery cooling plates was examined at actual high-speed climbing and low-temperature heating operating conditions. The results indicate that compared to the original smooth cooling plate, the square-ribbed battery cooling plate with a 60° angle and 5 mm spacing reduced the maximum battery temperature by 0.3 °C, but increased the cross-sectional temperature difference by 0.357 °C. To address this issue, a gradient rib arrangement was proposed, which slightly reduced the maximum battery temperature and lowered the cross-sectional temperature difference by 0.445 °C, significantly improving temperature uniformity. The thermal performance of the battery thermal management system with this gradient rib configuration meets the requirements for typical electric vehicle operating conditions, such as high-speed climbing and low-temperature heating conditions. [ABSTRACT FROM AUTHOR]

This paper reports on a novel hybrid thermal management strategy. It uses secondary coolants (air and liquid) to withdraw heat simultaneously from the composite phase change material, resulting in increased heat extraction capability of the composite phase change material and improved thermal environment of the battery module. The significance of this strategy is that the fluid used in the liquid cooling stays stationary. Comprehensive experimental and numerical studies are performed, and parametric studies are conducted to reduce the volume of the phase change material, size of the air duct, and airflow Reynolds number. The numerical results showed that the maximum temperature was limited to 27.8°C, and a high‐temperature uniformity of 0.4°C was obtained. Furthermore, the required volume of the composite phase change material is reduced by ~50%. Additionally, beyond a 6 mm height of the air duct, the reduction in maximum pressure drop is not significant enough, and it is considered the optimal height, and a Reynolds number of 1950 is considered the optimal airflow Reynolds number. Therefore, the proposed thermal management concept for the battery module can sustain the thermal environment needed for the effective operation of Lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

In the current era of energy conservation and emission reduction, the development of electric and other new energy vehicles is booming. With their various attributes, lithium batteries have become the ideal power source for new energy vehicles. However, lithium-ion batteries are highly sensitive to temperature changes. Excessive temperatures, either high or low, can lead to abnormal operation of the batteries, posing a threat to the safety of the entire vehicle. Therefore, developing a reliable and efficient Battery Thermal Management System (BTMS) that can monitor battery status and prevent thermal runaway is becoming increasingly important. In recent years, deep learning has gradually become widely applied in various fields as an efficient method, and it has also been applied to some extent in the development of BTMS. In this work, we discuss the basic principles of deep learning and related optimization principles and elaborate on the algorithmic principles, frameworks, and applications of various advanced deep learning methods in BTMS. We also discuss several emerging deep learning algorithms proposed in recent years, their principles, and their feasibility in BTMS applications. Finally, we discuss the obstacles faced by various deep learning algorithms in the development of BTMS and potential directions for development, proposing some ideas for progress. This paper aims to analyze the advanced deep learning technologies commonly used in BTMS and some emerging deep learning technologies and provide new insights into the current combination of deep learning technology in new energy trams to assist the development of BTMS. [ABSTRACT FROM AUTHOR]

The power battery is a key component of electric vehicles and its performance is greatly affected by temperature. Battery thermal management systems based on phase change materials can effectively control the battery temperature and at the same time have the advantages of simple structures, energy savings, and good temperature uniformity, and has broad development prospects. In this paper, expanded graphite–paraffin composite phase change materials were prepared, phase change material cooling experiments were carried out, and a phase change material cooling simulation model was also established using the Fluent software to study the influence of phase change material thermophysical parameters on thermal management performance. The results show that the phase change material thermal management method has excellent cooling performance. The best thermal management performance is achieved at the 3C discharge rate, with a phase change material filling thickness of 4 mm, a melting point of 40 °C above ambient temperature, and a thermal conductivity of 3 W/(m·K). When the phase change latent heat was increased from 150 J/g to 250 J/g, the liquid phase ratio decreased from 0.84 to 0.51, and the subsequent cooling performance was greatly improved, so the phase change latent heat should be increased as much as possible. [ABSTRACT FROM AUTHOR]

Currently, the conventional heat pipe form and working fluid are not well suited for power batteries. Existing simulation studies on battery thermal management with coupled heat pipes often overlook the two-phase flow and heat transfer of working fluid within the heat pipe. Additionally, the temperature difference between electrode region and cell is neglected in thermal behaviour simulation of the battery. Aiming at these problems, this paper proposes the design of an L-shaped heat pipe, which aims to efficiently adapt to heat dissipation of square batteries and the spatial arrangement within the battery module. And the phase change, flow and heat transfer processes of working fluid inside heat pipe are simulated and reproduced using the VOF (volume of fluid) method. Additionally, a CFD (computational fluid dynamics) model of an 8S1P ternary lithium-ion battery module is established based on the NTGK (Newman, Tiedemann, Gu, and Kim) method. Focusing upon thermal behaviour properties of the 8S1P battery module at different discharge rates, we investigate and optimize the thermal management efficiency of L-shaped heat pipes coupled with air cooling. The analysis reveals that the battery module model provides a more accurate representation of the temperature field on the body of batteries and the temperature variation among them. The evaporation-condensation process of the working fluid inside the heat pipe can continue in dynamic equilibrium, and the heat transfer effect through phase transition is well. With battery discharge rates varying from 1C to 3.5C, the addition of forced air cooling and introduction of cold air from air conditioning allows efficient control of temperature and temperature difference of the module, resulting in an ideal cooling effect. This study further improves the accuracy of the design and simulation of BTM (battery thermal management) that coupled with heat pipes, which can provide certain reference for related research. [ABSTRACT FROM AUTHOR]

Electric mobility decarbonizes the transportation sector and effectively addresses sustainable development goals. A good battery thermal management system (BTMS) is essential for the safe working of electric vehicles with lithium‐ion batteries (LIBs) to address thermal runaway and associated catastrophic hazards effectively. However, PCMs suffer from low thermal conductivity issues, and hence, enhancement techniques include the use of fins, nano‐additives, extended graphite powder, and so forth. The use of composite phase change materials effectively addresses LIB thermal management widely used in electric vehicles while mitigating thermal runaway, besides providing flame retardancy, thermal/mechanical stability, and electrical insulation, and preventing leakage. It is noted that no single strategy of BTMS is brought down to a safe zone of temperature, and hybrid BTMSs are being employed, invariably involve phase change materials (PCMs) to a large extent. It is essential to utilize CPCMs to address the effects of low‐temperature environments and vibrations considering vehicle driving cycles and operating conditions. It is observed from the review that ultrasonic monitoring and early detection of internal short circuits are the steps towards mitigation of thermal runaway propagation. It is required to utilize optimization methods, machine learning and IoT tools for a feasible PCM based BTMS work. Present review briefly describes potential methods for effective utilization of PCMs, comparison among different methods, challenges associated and potential solutions. It is highly essential to develop compact and economical BTMS with effective CPCMs for better and safer LIB operation to attract large‐scale commercialization of electric vehicles. [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]

Battery design efforts often prioritize enhancing the energy density of the active materials and their utilization. However, optimizing thermal management systems at both the cell and pack levels is also key to achieving mission-relevant battery design. Battery thermal management systems, responsible for managing the thermal profile of battery cells, are crucial for balancing the trade-offs between battery performance and lifetime. Designing such systems requires accounting for the multitude of heat sources within battery cells and packs. This paper provides a summary of heat generation characterizations observed in several commercial Li-ion battery cells using isothermal battery calorimetry. The primary focus is on assessing the impact of temperatures, C-rates, and formation cycles. Moreover, a module-level characterization demonstrated the significant additional heat generated by module interconnects. Characterizing heat signatures at each level helps inform manufacturing at the design, production, and characterization phases that might otherwise go unaccounted for at the full pack level. Further testing of a 5 kWh battery pack revealed that a considerable temperature non-uniformity may arise due to inefficient cooling arrangements. To mitigate this type of challenge, a combined thermal characterization and multi-domain modeling approach is proposed, offering a solution without the need for constructing a costly module prototype. [ABSTRACT FROM AUTHOR]

In order to improve the energy efficiency of pure electric vehicles, the author proposes a thermal energy recovery and automation monitoring system for motor equipment based on new energy vehicles. Based on the analysis of the battery thermal management model, a series heat exchange model between the motor and the battery was established. An integrated thermal management system control strategy based on motor waste heat recovery was proposed for electric vehicles in low temperature environments, and simulation and validation were conducted at different environmental temperatures (-10~0 °C). The simulation results show that this configuration can shorten the heating time by 111-343 seconds compared to traditional battery thermal management systems during the heating stage. During the insulation stage, frequent activation of positive temperature coefficient thermistor can be avoided and the battery temperature can be maintained around 20 °C, which is not only conducive to extending the battery life but also reduces the comprehensive energy consumption by 4.39-7.70%. On the other hand, this configuration can reduce the impact of low temperature on comprehensive energy consumption from 9.77-2.07%. It is proved that heat recovery can effectively alleviate the range anxiety caused by ambient temperature. [ABSTRACT FROM AUTHOR]

In this study, a comprehensive simulation study was carried out to obtain detailed battery temperature behaviors. The influences of air inlet temperature, air flow rate, C‐rate, and free stream temperature were investigated on the temperature uniformity and maximal battery temperature. Taguchi design is implemented to investigate the main effects of four control parameters in the battery thermal management process. Results indicated that as the free stream temperature (delta = 7.3366) was the most influential factor for the temperature uniformity, the air inlet temperature (delta = 0.2679) was the most efficient factor for the maximal battery temperature. The contribution of the air inlet temperature was 28% and 38% for temperature uniformity and maximal battery temperature, respectively. Additionally, the free stream temperature contributed 32% to temperature uniformity and 25% to the maximum battery temperature. The airflow rate was found to be the least effective factor for temperature uniformity (delta = 2.8672) and maximal battery temperature (delta = 0.0506). The results could be helpful in the design of a lithium‐ion battery thermal management process to improve temperature uniformity and maximal battery temperature. [ABSTRACT FROM AUTHOR]

Thermal management is a crucial design aspect for the safety and performance of the Lithium-ion battery pack used in electric vehicles. Phase change material (PCM) based battery thermal management is one of the appropriate passive or hybrid thermal management. The present paper highlights the selection of PCM depends on various factors related to application operating conditions like ambient temperature, the heat released by the battery, and the type of battery pack design. In selecting PCM, a thorough understanding of various PCMs requires an overall review of multiple types and properties of organic and inorganic PCM, using phase change equilibrium diagrams to comprehend phase change transformations. Further, the present work summarizes the various studies on PCM durability, different thermal performance enhancement techniques, and methodology for selecting PCM; as a result, assisting the researchers and engineers in choosing the appropriate PCM for the various EV battery thermal management applications in terms of chemical, thermal, and economic aspects Graphical Abstract [ABSTRACT FROM AUTHOR]

Liquid‐cooling techniques are commonly employed for battery thermal management (BTM) in commercial vehicles and energy storage applications, typically incorporating a cooling plate positioned beneath the casing of the battery pack. However, this heat transfer structural design results in smaller temperature drop in the terminal batteries located distantly from the plate, leading to an increased temperature difference. The integration of supplementary media into BTM systems holds the potential to enhance thermal management performance, thereby offering a viable solution to this issue. Herein, a fan is incorporated into the liquid‐cooling system to induce air circulation and augment convective heat transfer onto the battery surface. In the findings, it is revealed that the implementation of a reverse airflow path beneath the cooling plate result in a temperature decreasing rate of 0.59 K min−1, indicating a notable enhancement of 23% compared to solely employing a liquid‐cooling configuration. In the results, it is demonstrated that 1) reducing the inlet temperature can effectively enhance the rate of temperature reduction and 2) increasing the fan speed can reduce the temperature difference and promote temperature uniformity. In conclusion, in this present study, comprehensive guidelines and references are provided for the future design of BTM. [ABSTRACT FROM AUTHOR]

Compared to the use of positive temperature coefficient (PTC) materials that consume electrical energy for low-temperature heating, heat pump air conditioners can provide more energy-efficient heating performance by absorbing and utilizing heat from the outdoor air to heat the cab in order to improve the range of electric vehicles. In addition, in order to make the battery work under safe working conditions, this paper proposes battery thermal management coupled with vapor injection heat pump air conditioning. The system is modeled and analyzed through simulation, and the impact of the compressor speed and ambient temperature changes in the battery cooling performance of the system. The results show that under different compressor RPM (Revolution Per Minute) with an ambient temperature of 5 °C, the average temperature of the battery pack remains below 30 °C, and the majority of individual cell temperatures are maintained within the range of 20 to 35 °C. At a constant compressor RPM of 4000/min under varying ambient temperatures, the average temperature of the battery pack remains below 30 °C, with the majority of individual cell temperatures staying within the range of 20 to 35 °C. And the battery cooling performance still performs well. In the low temperature of −10 °C and −20 °C, the system can still maintain a relatively stable heating capacity compared with the 2009.1W, provided by the environment temperature of 5 °C at the same RPM. [ABSTRACT FROM AUTHOR]

This paper introduces a novel hybrid thermal management strategy, which uses secondary coolants (air and fluid) to extract heat from a phase change material (paraffin), resulting in an increase in the phase change material's heat extraction capability and the battery module's overall thermal performance. A novel cold plate design is developed and placed between the rows and columns of the cells. The cold plate contains a single fluid body to improve the thermal performance of the battery module. Experimental studies were conducted to obtain the temperature and heat flux profiles of the battery module. Moreover, a numerical model is developed and validated using the experimental data obtained. The numerical data stayed within ±2% of the experimental data. In addition, the ability of nanoparticles to increase the thermal conductivity of water is examined and it is found that the cooling from the liquid cooling component is not sensitive enough to capture the 0.32 W/m K increase in the thermal conductivity of the fluid. Furthermore, in order to enhance the air cooling, fins were added within the air duct to the cold plate. However, this is not feasible, as the pressure drop through the addition of the fins increased by ~245%, whereas the maximum temperature of the battery module reduced by only 0.6 K. Finally, when scaled up to an entire battery pack at a high discharge rate of 7 C, the numerical results showed that the overall temperature uniformity across the pack was 1.14 K, with a maximum temperature of 302.6 K, which was within the optimal operating temperature and uniformity ranges. Therefore, the developed thermal management strategy eliminates the requirement of a pump and reservoir and can be scaled up or down according to the energy and power requirements. [ABSTRACT FROM AUTHOR]

This study focused on the design of a battery pack cooling channel based on a Tesla Model S electric car. This study aimed to achieve a balance between cooling efficiency and pressure drop while maintaining safe and optimal operating temperatures for the batteries. A cooling channel design similar to the basic type employed in the Tesla Model S using 448 cylindrical Li-ion batteries was considered. Consequently, important parameters, such as the maximum temperature and temperature difference in the battery cells in a module, as well as the pressure drop of the coolant, were analyzed. In addition, the characteristics of the temperature changes in each cooling channel shape were investigated. The temperature limit for the battery in a module and the temperature limit difference were set to 40 °C and 5 °C, respectively, to evaluate the performance of the cooling system. Further, the effects of discharge rates (3C and 5C), cooling channel shapes (counter flow and parallel types), and coolant inlet velocities (0.1, 0.2, 0.3, and 0.4 m/s) on battery thermal management were analyzed. The results revealed that the parallel type channel yielded a lower pressure drop than the basic type channel; however, it was not as effective in removing heat from the battery. In contrast, the counter flow type channel effectively removed heat from the batteries with a higher coolant pressure drop in the channel. Therefore, a multi-counter flow type cooling channel combining the advantages of both these channels was proposed to decrease the pressure drop while maintaining appropriate operating temperatures for the battery module. The proposed cooling channel exhibited an excellent cooling performance with lower power consumption and better heat transfer characteristics. However, relatively minimal differences were confirmed for the maximum temperature and temperature difference in the battery module compared with the counter flow type. Therefore, the proposed cooling channel type can be implemented to ensure the optimal temperature operation of the battery module and to decrease system power consumption. [ABSTRACT FROM AUTHOR]

Excessive temperature of battery pack causes the performance degradation, affecting the normal operation and safety of the electric vehicles (EVs). This paper proposes an ant colony optimization-fuzzy sliding mode control (ACO-FSMC) hierarchical strategy for the battery thermal management system (BTMS) of EVs. Ignoring the dynamic process of the pump and compressor leads to the deviation of the cooling efficiency of EVs. Therefore, a control-oriented BTMS model is established to describe the temperature dynamics of battery pack and coolant, considering driving current effect on the speed of pump and compressor. Then, a hierarchical optimization strategy is designed to realize the control of the battery cooling rate as well as the speed of the pump and compressor. The upper layer of controller use an ant colony optimization (ACO) to solve the reference speed of the pump and compressor while satisfying constraints of physical characteristics of actuators, aiming at reducing battery temperature deviation and saving energy of BTMS. Considering the nonlinearity of lower layer of BTMS caused by the disturbance of time-varying load torque, fuzzy sliding mode control (FSMC) is applied to control the speed of pump and compressor, in which an integral sliding surface is designed to reduce the influence of disturbance. In order to weaken the chattering of sliding mode control and reduce energy consumption, fuzzy controller is used to adjust the reaching law parameters of sliding mode surface. The simulation results show that compared with PID, the maximum temperature deviation of ACO-FSMC is reduced by 43%, and the energy consumption is reduced by 23%. • A control-oriented battery thermal management model is established. • The dynamic process of the pump and compressor is considered. • ACO is used to solve the reference speed of the pump and compressor. • Fuzzy sliding mode control is applied to weaken the chattering of system. • The cooling performance and energy saving of the proposed method is verified. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, the effects of battery thermal management (BTM), pumping power, and heat transfer rate were compared and analyzed under different operating conditions and cooling configurations for the liquid cooling plate of a lithium-ion battery. The results elucidated that when the flow rate in the cooling plate increased from 2 to 6 L/min, the average temperature of the battery module decreased from 53.8 to 50.7 °C, but the pumping power increased from 0.036 to 0.808 W. In addition, an increase in the width of the cooling channel and number of channels resulted in a decrease in the average temperature of the battery module and a reduction in the pumping power. The most influential variable for the temperature control of the battery was an increase in the flow rate. In addition, according to the results of the orthogonal analysis, an increase in the number of cooling plate channels resulted in the best cooling performance and reduced pumping power. Based on this, a cooling plate with six channels was applied to both the top and bottom parts, and the top and bottom cooling showed sufficient cooling performance in maintaining the average temperature of the battery module below 45 °C. [ABSTRACT FROM AUTHOR]

The primary objective of this study was to explore the impact of integrating nano-additives on heat transfer enhancement within an LHTES (Latent Heat Thermal Energy Storage) system. Our findings revealed that introducing a minimal amount of nano-materials (less than 5.0 vol%) into the Phase Change Material (PCM) led to a remarkable alignment between experimental correlations and mixture models. Furthermore, employing the mixing model allowed for the accurate prediction of outcomes. In the current context of scientific research, there is a strong endorsement for the widespread adoption of Electric Vehicles (EVs) as a sustainable alternative to Internal Combustion Engines (ICEs), crucial for advancing decarbonization and mitigating climate-related crises. Lithium-ion batteries are the predominant choice for EVs and various electrical devices. However, the operational challenges posed by high temperatures, impacting their lifespan, charge/discharge cycles, and the risk of thermal runaway, necessitate effective thermal management systems. Given this background, our study focuses on simulating the heat dissipation of a single cylindrical Li-ion battery cell employing a Nano-enhanced Phase Change Material (NePCM)-based cooling system. We also introduce a novel fin design in this work. Through comprehensive analysis, we examine the performance of battery modules utilizing PCM and NePCM at different discharge rates, both with and without the newly proposed fin design. Our research demonstrates that the incorporation of fins and nanoparticles into PCM significantly enhances heat transfer and reduces the charging time compared to the base PCM. Notably, carbon-based nanoparticles outshine their metal-based counterparts in terms of melting rate and maintaining a uniform temperature profile within the battery. [ABSTRACT FROM AUTHOR]

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In this paper, an experimental and numerical study was conducted to analyze the performance of a hybrid thermal management concept for cylindrical lithium-ion battery modules at various discharge rates. The proposed concept consists of primary cooling through phase change material (PCM) and secondary cooling through vertical liquid channels between the PCM and airflow at the top of the cells. Two experimental studies were performed to obtain the temperature and heat flux profiles. In addition, the thermal performance of the battery module was obtained for 1 C, 2 C, 3 C, 5 C, and 7 C discharge rates using the numerical study. The results show that the maximum temperature was limited to ~30 °C. Additionally, the temperature uniformity in all the discharge rates was maintained below 5 °C. Finally, a meager amount of PCM was utilized during all the discharge cycles. At 1 C none of the PCM changed its phase, whereas at 2 C, 0.32%, 3 C, 0.14%, 5 C, 0.3%, and at 7 C, 0.12% of PCM changed its phase. The proposed hybrid concept can maintain the thermal environment required by the Li-ion cells for effective performance. Furthermore, this concept does not require excessive pumping fluid power and high air velocities, which reduces the energy required for the operation of the thermal management system, thereby increasing the available energy for propulsion. [ABSTRACT FROM AUTHOR]

Electrification on transportation and electricity generation via renewable sources play a vital role to diminish the effects of energy usage on the environment. Transition from the conventional fuels to renewables for transportation and electricity generation demands the storage of electricity in great capacities with desired power densities and relatively high C-rate values. Yet, thermal and electrical characteristics vary greatly depending on the chemistry and structure of battery cells. At this point, lithium-ion (Li-ion) batteries are more suitable in most applications due to their superiorities such as long lifetime, high recyclability, and capacities. However, exothermic electrochemical reactions yield temperature to increase suddenly which affects the degradation in cells, ageing, and electrochemical reaction kinetics. Therefore, strict temperature control increases battery lifetime and eliminates undesired situations such as layer degradation and thermal runaway. In the literature, there are many distinct battery thermal management strategies to effectively control battery cell temperatures. These strategies vary based on the geometrical form, size, capacity, and chemistry of the battery cells. Here, we focus on proposed battery thermal management strategies and current applications in the electric vehicle (EV) industry. In this review, various battery thermal management strategies are documented and compared in detail with respect to geometry, thermal uniformity, coolant type and heat transfer methodology for Li-ion and post-lithium batteries. [ABSTRACT FROM AUTHOR]

The hybrid fuel cell/battery technology is an attractive option for a sustainable mobility with zero emissions. In fact, this solution owns system scalability features and high efficiency and, compared to battery electric solutions, it offers advantages in terms of flexibility of use and fast charging times. However, the thermal management for the battery in this type of powertrain is a crucial issue, since operating temperatures can significantly affect safety and performance. In this study, an innovative system aimed at providing high storage energy density and improving the battery pack performance of hybrid fuel cell/battery vehicles is investigated for use on-board of a plug-in fuel cell electric bike. The proposed system, developed by the authors in previous studies, integrates the battery pack with a hydrogen storage based on metal hydrides. The idea behind this solution is to exploit the endothermic desorption processes of hydrogen in metal hydrides to cool down the battery pack during operation. An experimental analysis is conducted to assess the thermal management capabilities of this system: by considering a typical duty cycle designed on the base of road test measurements, battery pack temperature profiles are evaluated and compared against those from a control experiment where no battery thermal management is enabled (i.e. no hydrogen desorption from the metal hydride tank). The results show that, beside enhancing the on-board stored energy capacity, the proposed system represents an effective solution to provide an efficient thermal management for the battery pack, with significant advantages in terms of attainable riding range. • Plug-in fuel cell electric bicycle with greater riding range than e-bike. • On-board storage system integrating metal hydrides tank and battery pack. • Enhanced volumetric and gravimetric on-board energy storage density. • Optimal thermal management of battery pack and metal hydride tank. [ABSTRACT FROM AUTHOR]

The accumulation of thermal energy in the form of latent heat of phase transition using phase change materials (PCMs) is one of the most attractive and studied research areas with huge application potential in both passive and active technical systems. The largest and most important group of PCMs for low-temperature applications are organic PCMs, mainly paraffins, fatty acids, fatty alcohols, and polymers. One of the major disadvantages of organic PCMs is their flammability. In many applications such as building, battery thermal management, and protective insulations, the crucial task is to reduce the fire risk of flammable PCMs. In the last decade, numerous research works have been performed to reduce the flammability of organic PCMs, without losing their thermal performance. In this review, the main groups of flame retardants, PCMs flame retardation methods as well as examples of flame-retarded PCMs and their application areas were described. [ABSTRACT FROM AUTHOR]

Adhering to the thermal management requirements of prismatic battery modules, an improved lightweight parallel liquid cooling structure with slender tubes and a thin heat-conducting plate is proposed. The multiobjective optimization of the structure, operating parameters of the thermal management system, and thermal characteristics of a battery module are carried out. The effects of the equivalent diameter of the square tubes and the inner diameter of the circular tubes on the maximum temperature, maximum temperature difference of the batteries, and coolant pressure drop of liquid cooling battery thermal management system (BTMS) are investigated. The more significant factors, selected as the design variables, are the equivalent diameter of the square tubes, the inner diameter of the circular tube, and the coolant inlet velocity. Combining the computational fluid dynamics (CFD) method with multiobjective optimization, the different conditions of heat management parameters obtained by Latin hypercube sampling are numerically calculated, and the optimization of these parameters is carried out by the second-generation Elitist Nondominated Sorting Genetic Algorithm (NSGA-II). Compared with the thermal characteristics of the battery module before optimization, the maximum temperature of the module after optimization is reduced by 9.3%, the maximum temperature difference is reduced by 20.7%, and the coolant pressure drop from inlet to outlet is reduced by 49.1%. [ABSTRACT FROM AUTHOR]

Paraffin phase change materials (PCMs) exhibit great potential in battery thermal management (BTM); nevertheless, their application has been hampered by the handicap of low thermal conductivity, leakage, and volume expansion during phase transition. In this work, ternary composite PCMs formed of paraffin, expanded graphite (EG), and low-density polyethylene (LDPE) were developed for application in BTM. The structure and properties of the composite PCMs were characterized via X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, and thermal constant analysis. The result shows that EG can form a large-size graphite frame as heat conduction paths to improve the thermal conductivity of the composite PCM, and LDPE can form an interpenetrating network within the composite PCM to resist the internal stress of paraffin expansion and prevent deformation. The latent heat and thermal conductivity of the composite PCMs loaded with 10 wt% EG and 4 wt% LDPE can reach 172.06 J/g and 3.85 Wm−1K−1 with a relatively low leakage ratio of 6.2 wt%. Remarkably, the composite PCMs could reduce the temperature rise of the battery by 55.1%. In brief, this work provides a feasible route to develop high-performance PCMs for BTM. [ABSTRACT FROM AUTHOR]

The selection of a battery thermal management technique is important to overcoming safety and performance problems by maintaining the temperature of batteries within a desired range. In this study, a LiFePO4 (LFP) pouch-type battery having a capacity of 20 Ah was experimentally cooled with both air and liquid (immersion cooling) techniques. Distilled water was selected as the immersion fluid in the experiments, and the impact of discharge rate (1–4C), immersion ratio (50–100%), and coolant fluid inlet temperature (15–25 °C) on the battery temperature were investigated during the discharge period. The experiments revealed that maximum temperatures were reached at approximately 45 °C and 33 °C for air and distilled water cooling techniques, respectively, at the discharge rate of 4C. The average and maximum battery surface temperatures can be reduced by 28% and 25%, respectively, with the implementation of the liquid immersion technique at the discharge rate of 4C compared to the air technique. Moreover, the experiments demonstrated that the maximum temperature difference could be lowered to 4 °C by means of 100% liquid immersion cooling at the highest discharge rate, where they are approximately 11 °C and 12 °C for air and 50% for immersion cooling, respectively. In addition, it was observed that the coolant fluid inlet temperature has a significant impact on battery temperature for %100 liquid immersion. [ABSTRACT FROM AUTHOR]

Refrigerant indirect contact phase-change cooling system flows refrigerant into a cold plate and utilizes the phase-change to exchange heat with the battery. However, R134a, commonly used, is being gradually restricted due to its environmental impact. A new kind of near azeotrope mixed refrigerant R1234yf/R152a (mass ratio 60.5:39.5) is proposed under environmental protection and safety. Based on the fluid-structure interaction model, the evaluation of different indirect contact phase-change cooling systems for battery thermal management (BTM) using R1234yf/R152a is investigated. After obtaining battery (150 Ah, 3.2 V LiFePO4) parameters, heat generation power, and main test conditions through experiments, the thermal properties are numerically studied by computational fluid dynamics (CFD). At 1 C discharge rate, the temperature gradient (TG) of single battery and the maximum temperature difference (TD) among batteries are analyzed for two cases: The maximum TD among batteries of Case_b is 6.5°C lower than that of Case_a. In addition, the effect of the mixed refrigerant and traditional liquid cooling on the battery temperature is studied at different evaporation temperatures (ETs) (20°C, 25°C) and different mass flow rates (MFRs) (0.02, 0.10, and 0.18 kg/s). The results show that both the increase of inlet MFR and the reduction of inlet ET may significantly improve the battery module cooling rate. Compared with 0.02 kg/s, as the MFR increases, the temperature drop slopes to 9.56 and 11.2 at 20°C. The battery module temperature uniformity is improved with the increase of ET. Overall, the mixed refrigerant has advantages in temperature uniformity and consistency. The new mixed refrigerant plays a positive role in controlling battery temperature. [ABSTRACT FROM AUTHOR]

In a battery cooling system, by adopting a cooling optimization control strategy, the battery temperature under different external environments and load currents can be adjusted to ensure performance and safety. In this study, two modes of the thermal management system are established for the 6s4p (six serial and four parallel batteries in a stage) battery pack. A single particle model, considering battery aging, is adopted for the battery. Furthermore, a cooling optimization control strategy for the battery is proposed based on the triple-step nonlinear method, and then the optimization effect is validated under two C-rate charge–discharge cycles, NEDC cycles, and US06 cycles. Moreover, an extended PID control strategy is constructed and compared with the triple-step nonlinear method. A comparison of pump power, thermal behavior, and aging performance indicate parallel cooling is more advantageous. This verifies the validity of the triple-step nonlinear method and shows its advantages over the extended PID method. The present study provides a method to investigate the thermal behavior and aging performance of a battery pack in a BTM system, and fills in the research gaps in the cooling optimization control strategy for battery packs. [ABSTRACT FROM AUTHOR]

Battery pack specific energy, which can be enhanced by minimising the mass of the battery thermal management system (BTMS), is a limit on electric fixed-wing flight applications. In this paper, the use of phase-change materials (PCMs) for BTMSs is numerically explored in the 3D domain, including an equivalent circuit battery model. A parametric study of PCM properties for effective thermal management is conducted for a typical one-hour flight. PCMs maintain an ideal operating temperature (288.15 K–308.15 K) throughout the entire battery pack. The PCM absorbs heat generated during takeoff, which is subsequently used to maintain cell temperature during the cruise phase of flight. In the control case (no BTMS), battery pack temperatures fall below the ideal operating range. We conduct a parametric study highlighting the insignificance of PCM thermal conductivity on BTMS performance, with negligible enhancement observed across the tested window (0.1–10 W m−1 K−1). However, the PCM's latent heat of fusion is critical. Developers of PCMs for battery-powered flight must focus on enhanced latent heat of fusion, regardless of the adverse effect on thermal conductivity. In long-haul flight, an elongated cruise phase and higher altitude exasperate this problem. The unique characteristics of PCM offer a passive low-mass solution that merits further investigation for flight applications. [ABSTRACT FROM AUTHOR]

To improve the operating performance of the large-capacity battery pack of electric vehicles during continuous charging and discharging and to avoid its thermal runaway, in this paper we propose a new hybrid thermal management system that couples the PCM with the liquid cooling plate with microchannels. The flow direction of the microchannel structure in the bottom plate is designed according to the characteristics of the large axial thermal conductivity of the battery, and the cooling performance of the whole system under continuous charge/discharge cycles is numerically simulated. The results show that the hybrid PCM/liquid cooling plate can maintain good cooling performance under the discharge process of a large-capacity battery pack. After each cycle the temperature of the battery pack can be reduced to less than 30°, and the maximum temperature change rate of multiple cycles is controlled within 0.8%. With the application of the hybrid PCM/liquid-cooled plate battery cooling system, a safe temperature range of the battery pack is ensured even under multiple cycles of charging and discharging. The present work can facilitate future optimizations of the thermal management system of the large-capacity battery pack of electric vehicles. [ABSTRACT FROM AUTHOR]

[Display omitted] • The thermal application of carbon nanotube from waste plastic was firstly studied. • The thermal conductivity of phase change composite material increased by 104%. • Latent heat capacity of phase change composite material retains 90.7%. • The produced carbon nanotube shows similar potential as commercial carbon nanotube. • This phase change nanocomposite is promising for battery thermal management. Carbon nanotube (CNT), has been demonstrated as a promising high-value product from thermal chemical conversion of waste plastics and securing new applications is an important prerequisite for large-scale production of CNT from waste-plastic recycling. In this study, CNT, produced from waste plastic through chemical vapor deposition (pCNT), was applied as a nanofiller in phase change material (PCM), affording pCNT-PCM composites. Compared with pure PCM, the addition of 5.0 wt% pCNT rendered the peak melting temperature increase by 1.3 ℃, latent heat retain by 90.7%, and thermal conductivity increase by 104%. The results of morphological analysis and leakage testing confirmed that pCNT has similar PCM encapsulation performance and shape stability to those of commercial CNT. The formation of uniform pCNT cluster networks allowed for a large CNT loading into the PCM on the premise of free phase change, responsible for the high thermal conductivity inside the homogeneous phase. Thus, the resulting capillary forces retained a high latent heat capacity and suitable melting temperature and prohibited PCM leakage from the matrix to the outside during re-melting as the pCNT loading ratio increased. Therefore, the as-prepared pCNT-PCM composite is believed to have similar potential to cCNT and shows prominent performance as a flowable conductive filler for battery thermal management systems. [ABSTRACT FROM AUTHOR]

The battery thermal management system with phase change material coupled cold plates was investigated with the numerical simulation method. The results show that, the temperature and temperature difference of the battery pack decreases with the increase of the flow rates of the cold plate in the system, while the power consumption of the cold plate significantly increases, which leads to poor efficiency of the system. To improve the efficiency of the coupled thermal management system, an adjusting strategy was introduced to optimize the thickness distribution of phase change materials with the system volume fixed. The optimized results of typical cases show that, the optimal phase change material thickness distribution can be obtained by only 5 adjusting steps. Compared with the original system, the maximum temperature of the battery pack drops by 1.1 K and the temperature difference narrows down by 29% after the optimization. To achieve the same temperature difference in the battery pack, the power consumption of the optimized system lowers down by 64% compared with that of the original system. [ABSTRACT FROM AUTHOR]

Highlights: The phase change materials possess conformable configuration to the structure of Li-ion batteries in macro-scale and multidirectional thermal pathways for rapid and uniform heat transfer in micro-scale. Hierarchically structured phase change materials achieve dual-mode thermal management ability for heating and cooling Li-ion batteries. Excellent practical battery thermal management performance was verified by 18,650 Li-ion batteries in both cold and hot environments. Phase change materials (PCMs) are expected to achieve dual-mode thermal management for heating and cooling Li-ion batteries (LIBs) according to real-time thermal conditions, guaranteeing the reliable operation of LIBs in both cold and hot environments. Herein, we report a liquid metal (LM) modified polyethylene glycol/LM/boron nitride PCM, capable of dual-mode thermal managing the LIBs through photothermal effect and passive thermal conduction. Its geometrical conformation and thermal pathways fabricated through ice-template strategy are conformable to the LIB's structure and heat-conduction characteristic. Typically, soft and deformable LMs are modified on the boron nitride surface, serving as thermal bridges to reduce the contact thermal resistance among adjacent fillers to realize high thermal conductivity of 8.8 and 7.6 W m−1 K−1 in the vertical and in-plane directions, respectively. In addition, LM with excellent photothermal performance provides the PCM with efficient battery heating capability if employing a controllable lighting system. As a proof-of-concept, this PCM is manifested to heat battery to an appropriate temperature range in a cold environment and lower the working temperature of the LIBs by more than 10 °C at high charging/discharging rate, opening opportunities for LIBs with durable working performance and evitable risk of thermal runaway. [ABSTRACT FROM AUTHOR]

Liquid thermal management is the prevailing method to maintain the operating performance and safety of Li-ion batteries. However, a better heat transfer performance is often accompanied by a higher power cost for liquid-based cooling methods. In the present work, V-shaped intersecting bypasses are integrated into conventional serpentine channels to reduce the liquid pressure drop across the cold plate without loss of thermal performance. The thermal-hydraulic characteristics of the battery thermal management system are studied based on CFD simulations. The non-dimensional j/f factor is developed and adopted to evaluate the heat transfer ability and friction loss of different designs. The effects of intersecting channel addition, flow direction, channel inlet, and outlet distributions are explored with the simulation results and data analysis. The results show that all of these factors would impact the thermal–hydraulic characteristics of the liquid cold plate. The addition of intersecting channels remarkably reduces the power cost, thus increasing the j/f factor. The alteration of the flow direction from longitudinal to widthwise could further improve the thermal-hydraulic characteristics of the intersected channel design. For conventional serpentine channels, the inlet and outlet distributions show no evident impact on thermal performance. However, regarding the intersected cases, the thermal-hydraulic performance is enhanced when the inlet and outlet are placed on the opposite sides of the cold plate, especially when the inlet velocity is less than 0.3 m/s. The findings of this study could shed light on the liquid flow channel design for battery thermal management. [ABSTRACT FROM AUTHOR]

Application of refrigerant-cooled multi-channel evaporators (MCEs) is a promising solution to cool electric vehicle batteries because the non-uniformly distributed heat from a battery can be efficiently dissipated by suitable arrangement of the multi-channels in an MCE. In order to provide a simulation tool for the design of an MCE, a distributed parameter model for quickly predicting the performance of an MCE at various channel arrangements and non-uniformly distributed heating conditions is useful, and thus it is developed in this study. In the model, heat and mass transfer in multiple flow paths in an MCE are separately described; the uneven mass flow distribution among these channels is predicted based on the pressure balance; each flow path is divided into multiple control volumes to reflect the non-uniformly distributed heating conditions; and the mass flow distribution among flow paths and the heat transfer in all the control volumes are jointly solved by a combined iteration algorithm of pressure drop and heat transfer. The proposed model is validated by experiments under the condition of battery heat flux ranging from 500 to 1500 W m−2. The results show that the prediction deviations of the average temperature and the highest temperature on the MCE surface from the experimental ones are 1.5 °C and 1.6 °C, respectively, which indicates that the proposed model can well predict the thermal performance of MCE under non-uniformly distributed battery heat. • A distributed parameter model of refrigerant-cooled MCE for power battery is developed. • Refrigerant flow among multi-channels is modeled as uneven flow with fix direction. • Arbitrary heat flux input can be calculated by the model. • The average deviation of temperature predictions is less than 3.0 °C. [ABSTRACT FROM AUTHOR]

• Design for hybrid battery pack with high energy density and high safety. • Thermal Management Optimization Layout Design for Hybrid Battery Packs. • The P2D model is used to study electrochemical properties of single battery. • Multiphysics coupling analysis of electro-thermal behavior. • The SOC estimation method for hybrid battery pack. As traditional battery systems, lithium iron phosphate (LFP) batteries have better safety but lower energy density and nickel manganese cobalt oxide (NMC) batteries have higher energy density but poorer safety. In this work, we design a hybrid battery pack that has both higher energy density and higher battery safety. By analyzing the thermal properties of battery packs with aligned, staggered, and staggered arrangements, it can be concluded that the aligned arrangement has superior cooling efficiency and space-efficient optimization compared to the other arrangements, which have shorter flow paths to minimize air energy loss and reduce pressure drop. Notably, we design the optimal arrangement to avoid placing the NMC cells near the air outlet, to avoid NMC concentration, and to decentralize the LFP cells to reduce the relatively high maximum temperature and temperature difference. This hybrid battery pack is expected to give a boost to lithium-ion battery applications. [ABSTRACT FROM AUTHOR]

To maintain the optimal operating temperature range for the power batteries of new energy vehicles, this paper proposes a novel tree-structured channel cold plate. An orthogonal experimental approach was employed to investigate the effects of inlet flow rate m, inlet channel quantity n, channel width d, and hierarchy ratio α on battery temperatures T max , standard temperature difference T σ , and pressure drop Δ P. Non-dominated sorting genetic algorithm II (NSGA-II) was utilized to obtain an optimized solution set. The results reveal that the tree-like cold plate configuration including m = 15 g/s, n = 7 and 8, d = 3 mm, and α = 1:2:1 demonstrates superior performance. Thus, the developed cold plate was further compared with the conventional straight-through cold plate design. The results indicate that the proposed tree-like cold plate exhibits the maximum decreases of 13.94% in T max , 52.94% in T σ , and 61.5% in Δ P. The most significant improvement in the composite indicator PEC was 89%. In conclusion, the tree-like channel cold plate developed in this study provides excellent heat dissipation capability for power batteries, offering valuable insights for the thermal design of battery liquid cooling systems. [ABSTRACT FROM AUTHOR]

Electric autonomous underwater vehicles (AUVs) are facing more urgent battery thermal management (BTM) demands than electric cars, as their battery compartment design is constrained by limited volume, airtightness and impact loads. In this paper, a novel hybrid battery thermal management strategy of metal foam/paraffin composite combined with thermal bridges is proposed for the AUVs' BTM. A three-dimensional model considering the non-thermal equilibrium effect for AUVs' battery module was developed. Gradient PCMs and gradient foam porosity were introduced to improve the temperature and melting behaviors in various regions of AUVs' battery pack. The trade-off between performance and weight of metal foam/PCM composite on AUVs' battery thermal management was also quantitatively analyzed. The results showed that the temperature in the top region of the battery pack was higher than that in the bottom region due to the natural convection of the liquid PCM. The positive gradient porosity of metal foam has the advantages of large porosity increasing the heat storage and small porosity improving the thermal conductivity, both benefit to reduce the maximum temperature of the battery module. The positive gradient latent heat and melting point hybrid strategy of PCM demonstrates the best thermal management performance when compared with constant parameter cases, and the maximum temperature of battery modules is more sensitive to the melting point of PCM. When the metal foam/PCM composite was introduced, the weight of the battery module increased by 27.1%, while the maximum temperature and temperature difference of the battery module decreased by 44.27 K and 11.1 K, respectively. The safe working time of the battery module was extended by 105.7%, and the mass-energy density that can be utilized was increased by 61.9%. The findings can help AUVs to achieve the goals of high speed and long range. • The metal foam/paraffin composite was innovatively used for AUVs' BTM. • A 3D model was established considering non-thermal-equilibrium effect. • The thermal and melting behaviors of battery module were discussed in depth. • The performance of metal foam/paraffin with gradient parameters was compared. • The trade-off between performance and weight of metal foam/paraffin was evaluated. [ABSTRACT FROM AUTHOR]

Efficient cooling during rapid battery charging/discharging necessitates forced circulating flow in immersion cooling systems. However, under forced flow immersion cooling (FFIC), the comprehensive impact on the electrical and thermal performance of battery modules remains inadequately explored. This study constructs an immersion-cooled battery module test platform for experimental research on the evolution of electrical and thermal characteristics. The results show that under FFIC, when the depth of discharge (DOD) during 2C and 3C discharges is below 85 %, the voltage deviation of module (δ U,t) remains stable within 1 % and 2 %, respectively. At DOD of 100 %, the maximum δ U,t for 2C and 3C are 10 % and 24.5 %, respectively. Furthermore, the analysis of Pearson correlation coefficient under FFIC reveals that the δ U,t exhibits a very strong positive correlation with temperature difference of battery module and cell, with correlation coefficients of +0.94 and + 0.87, respectively. Higher flow rates accelerate the recovery of module temperature and facilitate voltage distribution equalization after discharge. Additionally, to elucidate the influence of flow rate on FFIC, module-scale heat transfer characteristics during battery discharge are theoretically analyzed, establishing a fitting relationship between C-rates, flow rates, and the Nusselt number (Nu). This study provides a comprehensive understanding of integrated electro-thermal performance and external heat transfer capability for flow regulation in immersion cooling. [Display omitted] • Immersion-cooled battery platform was developed for electro-thermal performance. • Evolution of module electro-thermal performance was analyzed at varied Re and C-rates. • Interaction and strength between electrical and thermal parameters were revealed. • Heat transfer characteristics during discharging were theoretically analyzed. • The relationships between discharge C-rate, Re and Nu were established. [ABSTRACT FROM AUTHOR]

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]

Different battery thermal management (BTM) for a 18650 cylindrical Li-ion battery pack were simulated based on the lumped model. Phase change material (PCM) was introduced for its benefits: high latent heat and uniform melting temperature. However, the heat absorbed into the PCM was not dissipated to the environment. Thus, an additional cooling mechanism was required to reach satisfying temperature limits (45 °C for lifespan and 50 °C for safety). These include natural convection cooling, forced convection cooling, finned-natural convection cooling, PCM cooling, and PCM cooling coupled with liquid cooling channels. The temperature of the battery pack using natural convection, finned-natural convection, and PCM cooling reached 62.1 °C, 55 °C, and 50 °C, which were equal or over (50 °C), while it decreased to 49 °C using forced convection, which was over (45 °C). However, PCM coupled with liquid cooling channels satisfied the requirements, and the temperature was reduced to 42 °C using this system. [ABSTRACT FROM AUTHOR]

Summary: The phase change material is currently being regarded as an effective cooling media to be applied in the thermal management of lithium batteries‐powered vehicles, in which the inorganic hydrate phase change material is desirable and widely investigated due to the high thermal conductivity, latent heat value, and low cost. However, when applied to thermal energy storage applications, supercooling and phase separation are problematic. To effectively circumvent this issue, this work considers utilizing the disodium hydrogen phosphate dodecahydrate as the matrix of the composite phase change material, as the phase transition temperature is suitable for the battery's operating temperature range. Meanwhile, the nucleating agent sodium metasilicate nonahydrate with similar lattice parameters and the thickener carboxymethyl cellulose are used to suppress the supercooling and eliminate the phase separation, respectively. Effects of nucleating agent, surface modified aluminum nitride, and short‐cut carbon fiber on the supercooling degree, and thermal conductivity and curing performance in the phase change material are evaluated and discussed in detail to determine the optimal preparation scheme for Na2HPO4·12H2O/modified AlN/CF inorganic composite phase change materials. Experimental results show that the addition of 4 wt% Na2SiO3·9H2O, 4 wt% CMC, 12 wt% modified AlN, and 6 wt% CF reduces the supercooling degree of the composite phase change material to 1.9°C and increases the thermal conductivity to 1.86 W/(m·K). The composite phase change material is found to have a suitable phase change temperature (35°C), high latent heat (249 J/g), excellent shaping effect, and electrical safety performance. In addition, the composite phase change material battery module can effectively control the battery's temperature, with the maximum temperature reduced by 40.9°C at 3C discharge rate and 30°C ambient temperature compared with the natural cooling battery module. The maximum temperature difference of the composite phase change material battery module is shown to be reduced to the minimum value of 0.9°C. Highlights: A novel disodium hydrogen phosphate dodecahydrate—modified aluminum nitride—carbon fiber composite phase change material is designed and prepared for battery thermal management systems.The antiwater modification scheme of AlN is proposed and assessed. The effects of AlN before and after modification on the thermal properties of CPCM are compared.The joint use of nucleating agent sodium metasilicate nonahydrate and thermal conductive filler AlN contributes to significantly inhibiting the supercooling of hydrate salt.The addition of CF can effectively increase the thermal conductivity of CPCM and prevent its leakage.CPCM has suitable phase change temperature, high thermal conductivity and latent heat value, excellent electrical safety, and stable curing performance.The battery test bench is constructed and the discharge test of the CPCM battery module is carried out. The results show that the CPCM battery module has excellent cooling performance and temperature uniformity. [ABSTRACT FROM AUTHOR]

This article surveys the mathematical principles essential for understanding the thermal management of Li-ion batteries, the current technological state of the art, and the solution. Since the thermal management of electric drive vehicles has environmental, economic, and safety impacts, this review focuses on the efficient methods of battery thermal management (BTM) that were proposed to overcome the major challenges in the electric vehicle industry. The first section examines the perspective of battery-driven vehicles, the principles of Li-ion batteries with a thermal runaway, and their implication for battery safety. The second section discusses mathematical approaches for effective BTM modeling, including the thermal-fluidic network model, lumped capacitance model, spatial resolution lumped capacitance model, equivalent circuit model, impedance-based model, and data-driven model. The third section presents the current state-of-the-art technologies, including air-based, liquid-based, PCM-based, in situ BTM methods, and heat pipe and thermoelectric module-based methods. The conclusion section summarizes the findings from existing research and the possible future directions to achieve and employ better thermal management techniques. [ABSTRACT FROM AUTHOR]

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Energy management strategies have a significant impact on the hydrogen economy of fuel cell trucks and the lifetime of battery and fuel cell systems. This contribution presents the design and optimal calibration of an energy management strategy that is adaptive to the battery and ambient temperatures. Indeed, fuel cell trucks face critical operating conditions due to high ambient temperatures or high loads on long uphill roads. However, the presented adaptive energy management strategy shifts the electric loads to the fuel cell system to limit the battery usage, avoiding accelerated degradation due to battery temperature peaks without hindering the hydrogen economy. The strategy design and calibration involves a multi-objective optimization of performance indicators related to hydrogen consumption, fuel cell degradation, battery thermal state, equivalent charge/discharge cycles, and charge control. This work uses AVL CAMEO to systematically vary the adaptive curve parameters to explore the trade-off between the key performance indicators. The calibration considers real-world driving cycles of road freight vehicles, including measured speed, road elevation, and variable vehicle mass. Moreover, the energy management design is robust because the performance indicators are evaluated over 8935 km, covering an extensive range of real-world driving scenarios. Eventually, the adaptive and predictive energy management strategy proposed in this work can meet all the performance targets thanks to the optimal calibration, and it is particularly effective in avoiding battery temperature peaks. [ABSTRACT FROM AUTHOR]

New energy power battery has a high current during fast charging and discharging, producing a huge amount of heat. The rational operation of the battery thermal management system (BTMS) plays an important role in increasing the energy storage capacity and service life of the power battery. This paper explores the battery thermal management and health state assessment of new energy vehicles. For the power battery of new energy vehicles, the fast charging is very likely to cause overheating. By analyzing this phenomenon, we derived a comprehensive control strategy for the charging and discharging of power battery, which optimizes the battery thermal management. Then, the main controlling factors were collaboratively controlled for the thermal management during the fast charging of the power battery of new energy vehicles, and the collaborative control standards and energy consumption laws of the system were discussed in details. After that, the backpropagation neural network (BPNN) was combined with adaptive genetic algorithm (AGA) to establish a nonlinear model between the health state indices and battery capacity of the power battery of new energy vehicles, and the model was applied to estimate the health state of the battery. Finally, the effectiveness of the proposed model was proved through experiments. [ABSTRACT FROM AUTHOR]

• The pseudo 3D topology optimization approach for cold plate design was introduced. • Penalty coefficients, objective function weights, and re substantially influenced the results of topology optimization. • Temperature variance constraints greatly enhanced topology optimized cold plate temperature uniformity. • Topology optimized cold plate showed excellent heat dissipation and temperature uniformity. • Topology optimized cold plates outperformed parallel flow channel cold plates in cooling performance. This study develops a liquid-cooled cold plate for battery packs in electric vehicles using pseudo three-dimensional topology optimization techniques. The objective of optimization is to reduce both temperature and energy consumption of flow, while simultaneously enhancing the temperature uniformity of the structure by using temperature variance as a constraint in the topology optimization procedure. An analysis was conducted to establish the structure of the cold plate by examining the impacts of topological optimization penalty coefficients, Reynolds number, objective function weights, and temperature variance limitations on the optimization outcomes. Ultimately, the numerical simulation assesses the thermal efficiency and flow properties of the topology optimized cold plate within a battery pack. It demonstrates superior heat dissipation and temperature uniformity when compared to the Parallel-channel cold plate. With a mass flow rate of 0.0052 kg/s, the battery equipped with topology optimized cold plate has an average temperature of 302.9 K, a maximum temperature of 304.25 K, and an internal temperature difference of 4.7 K. The average temperature is 1.18 K lower and the maximum temperature is 1.8 K lower compared to the battery with Parallel-channel cold plate. This study offers a highly effective resolution to the issue of cold plate design for battery heat dissipation. [ABSTRACT FROM AUTHOR]

• The introduction of top-mounted jets can enhance local fluid disturbance, effectively solving the problem of uneven thermal distribution in immersion cooling. • CFD is used for iterative optimization, analyzing each factor individually to enhance battery thermal management. • Flow rate is distributed between the main and jet inlets to save energy, lower battery temperature, and improve temperature distribution without increasing flow rates. This study introduces an innovative, synergistically optimized coupled cooling design that enhances lithium-ion battery thermal management for electric vehicles, merging jet impingement with immersion cooling techniques. Utilizing Computational Fluid Dynamics (CFD) numerical simulation, distributed iterative optimization is conducted. Initially, the inlet and outlet configurations are determined. Subsequently, the number of jet pipes and the flow distribution are optimized. Finally, the diameters of the jet pipes are refined. This process aims to enhance heat transfer efficiency and reduce total input cost. The results indicate that a design with three inlets and one outlet, using an inlet flow rate of 0.075 kg/s alongside the flow rate of 0.025 kg/s, achieves optimal thermal performance for the batteries. This configuration reduces the maximum battery temperature and average temperature by 17.61% and 15.05%, respectively. Furthermore, an excessive or insufficient number of jet pipes is detrimental to cooling within the battery. Relying solely on mainstream inlet or jet pipe coolant for refrigeration is far less effective than proportionally distributing flow between the two. Selecting 6 jet pipes and a distribution ratio of 2꞉1 can reduce the maximum temperature by 10.10%. In contrast to adjusting jet pipe diameters, optimizing flow distribution exerts a more significant influence on battery cooling efficiency. Ultimately, the optimized solution, compared to the original design (with a flow rate of 0.025 kg/s), reduces the maximum temperature and average temperature by 26.41% and 10.61%, respectively. These improvements demonstrate the effectiveness of coupling jet impingement and immersion methods in battery thermal management, offering valuable insights for the future development of EVs battery cooling technologies. [ABSTRACT FROM AUTHOR]

Employing phase change materials (PCMs) has become a promising approach in the field of battery thermal management. However, low thermal conductivity, liquid phase leakage, and high rigidity still limit its widespread application. In this paper, we dispersed boron nitride nanosheets (BNNS) and multi-walled carbon nanotubes (MWCNT) as binary thermally conductive fillers onto a three-dimensional porous flexible skeleton of silanized hydrophobically modified cellulose nanofiber (SCNF) to prepare a hybrid aerogel. By employing it as a flexible carrier, a shape-stable and thermally induced flexible composite phase change material (CPCM) with binary alkanes was successfully prepared. Experimental results show that the three-dimensional porous flexible skeleton structure of the hybrid aerogel effectively avoids the leakage of PCM and maintains good flexibility during melting. The synergistic dispersion strategy based on SCNF enables the BNNS/MWCNT binary filler to bridge a perfect thermal conduction path at a low loading of 1 vol%. When the ratio of BNNS to MWCNT on the three-dimensional skeleton of SCNF is 7:3, the prepared SC/35B/15M@PCM shows the best synergistic enhancement effect of 91.8% in thermal conductivity compared with pure PCM, while maintaining a high PCM load capacity of 94.51 wt% and a high phase change latent heat level of 213.27 J/g. In addition, based on the simulation results, the prepared SC/35B/15M@PCM shows a superior temperature control effect which reduce the temperature of commercial lithium-ion batteries by 3.42 °C–16.41 °C at a discharge rate of 1-3C. The CPCM synthesized in this work achieves a balance between shape stability, energy storage density, and thermal conductivity. • A new ternary thermally conductive flexible skeleton is successfully constructed. • Silanization modification enhanced the mechanical flexibility of hybrid aerogels. • Binary fillers show synergistic enhancement effect of thermal conductivity at 1 vol%. • CPCM has high paraffin loading capacity and insignificant leakage problem. • CPCM shows application potential in the field of the battery thermal management. [ABSTRACT FROM AUTHOR]

To efficiently ensure the suitable temperature for lithium-ion batteries, battery thermal management system based on phase change material (PCM) have gained considerable attention. A shape-stabilized composite PCM was prepared using the mixture of Na 2 SO 4 ·10H 2 O and KAl(SO 4) 2 ·12H 2 O hydrated salts as phase change substrate, expanded graphite as thermal conductive filler and open-cell polyurethane foam as support material. The composite PCM containing 4 wt.% expanded graphite displayed a satisfied phase change temperature of 30.8 °C and 69.8 °C, high latent heat of 226.9 J/g, and good thermal conductivity of 1.39 W/(m·K). Meanwhile, it obtained a low subcooling degree, good leakage resistance, and excellent flame retardancy properties. Under PCM cooling in sandwich structure, during 0.5C charging and 1.5C discharging cycles, the maximum temperature and maximum temperature difference of battery were 52.47 °C and 2.20 °C, decreased by 20.4 % and 59.7 % respectively compared with nature air cooling. Furthermore, the composite PCM could significantly relieve the thermal runaway propagation between lithium-ion batteries. This work provides a feasible design and application strategy of hydrated salt based PCMs for battery thermal management and thermal runaway mitigation. [Display omitted] • Hydrated salt based PCMs were prepared from hydrated salts, expanded graphite and open-cell polyurethane foam. • The thermophysical properties of PCMs are suitable for battery thermal management. • Hydrated salt based PCMs achieved a LOI value of above 86 % and passed UL-94 V-0 rating. • Maximum temperature difference of lithium-ion batteries with PCM cooling was as low as 2.20 ℃. • The novel PCMs greatly mitigated the thermal runaway propagation between lithium-ion batteries. [ABSTRACT FROM AUTHOR]