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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]

Summary: Phase change material (PCM) based battery thermal management system (BTMS) provides even heat distribution and lower maximum temperature, but it suffers from low thermal conductivity. In this study, the impact of graphene additive on PCM was analyzed by presenting three experiments with various structures to solve PCM's low thermal conductivity problem. The results demonstrate that there is no positive impact of graphene additive in the first and third structures. The PCM‐graphene additive between the second structure's fins significantly improves the battery heat transfer by allowing the battery to cool down 1500 seconds earlier than the graphene‐free structure. Moreover, a thermal equivalent circuit model was derived for the second structure because of its enhanced performance. It is shown that the model works accurately and proves its ability to control not only temperature fluctuations but also transient behavior of the battery. This model provides that the battery temperature can be analyzed without experimentation for different charge‐discharge scenarios in lithium‐ion batteries with a shorter computation time. [ABSTRACT FROM AUTHOR]

Summary: As lithium‐ion batteries (LIBs) are used in autonomous underwater vehicles (AUVs) power systems, their thermal safety and reliability have seriously inhibited the development of AUVs toward high speed and long voyage. However, the related research on AUVs' battery thermal management is very limited. In this article, a novel and efficient liquid cooling scheme is proposed, for battery thermal management of AUV, which adopts bionic wave cooling channels. A three‐dimensional heat dissipation model of the battery was developed, which considered the influence of battery internal resistance and state of charge on battery heat generation. The effects of discharge rate, channel shape, coolant mass flow rate, coolant inlet direction, and dynamic operation strategy on the battery maximum temperature and temperature variation were investigated during discharging process. It was found that the battery with bionic wave channels was superior to the battery with straight channels, regarding cooling efficiency. The maximum temperature and temperature difference of the former decreased by 12.8 and 5.3 K compared with the latter at 5C current discharging rate. Based on the bionic wave channels, increasing the mass flow rate of coolant was the most efficient route to reducing the maximum temperature and improving the uniformity of the battery temperature. A mass flow rate equal to 2.5 × 10−4 kg s−1 is reasonably recommended by considering the cooling efficiency comprehensively. The direction of the coolant inlet had little effect on the maximum temperature of the battery, but it significantly improved the uniformity of the battery temperature. Under the premise of meeting the cruising requirements of AUVs, alternating low‐rate and high‐rate discharge was more conducive to improving the temperature behavior of the battery. The conclusions of this article can provide reference for the battery thermal management system of AUVs. [ABSTRACT FROM AUTHOR]

Summary: Adding thermally conductive filler to polymer matrix is a workable way to increase its thermal conductivity. In this work, carbon fiber (CF) and hexagonal boron nitride (h‐BN) were employed to obtain hybrid fillers, firstly, (mh‐BN@CF) by electrostatic self‐assembly method, then added mh‐BN@CF to silicone rubber (SR) matrix to prepare mh‐BN@CF/SR composites. There was a good interface compatibility between mh‐BN@CF and SR matrix. Besides, the composites can achieve best thermal conductivity when h‐BN and CF are at the optimal fill ratio. When the mass ratio of h‐BN:CF is7:3 and the filling content is 54 phr, the thermal conductivity of mh‐BN@CF/SR can reach 1.3 W/(m K), and it is 23.7% and 400.4% larger than the mixed‐filled h‐BN/CF/SR composites and SR matrix, respectively. Simultaneously, the mh‐BN@CF/SR composites also exhibited good electrical insulation, mechanical properties, and thermal stability. Finally, the prepared composites are used in a liquid‐cooled battery thermal management system (BTMS). The effect of the composites on the performance of the BTMS is discussed by numerical method. The results show that the improved thermal conductivity of the composites can highly reduce the temperature of the battery cells. The prepared composites can highly enhance the performance of BTMS. [ABSTRACT FROM AUTHOR]

Summary: The structural design of a refrigerant plate and its flow property affect the thermal management performance of a battery. This study, aimed at improving the cooling and thermal uniformity based on the R134a cooling method, analyzed the flow resistance of the plate, temperature, and heat‐transfer coefficient of the top board of eight types (type A‐G) by the computational fluid dynamics method. By trade‐off between flow resistance and heat‐transfer efficiency, we determined the optimal type G plate with a modest pressure difference of 1670.6 Pa and the highest heat‐transfer coefficient of 810.8 W/(m2 K). In addition, the relationship between the operating parameters and temperature variation in battery modules and its uniformity has also been analyzed. The results indicate that with this novel cooling method, temperature uniformity of battery modules can be maintained within 5 K at 2C discharging rate. Both increasing inlet R134a flow rate and decreasing evaporative pressure obviously increase the temperature decrease rate of battery modules. With the inlet R134a mass flux ranging from 245 to 490 kg/(m2 s), the evaporative pressure ranging from 412 530 to 291 220 Pa, and the subcooling degree ranging from 0 to 4 K, the battery temperature can be maintained under 300 K. In conclusion, this study develops the guidelines for battery thermal management based on refrigerant cooling, which has a promising application foreground due to its good thermal control performance, flow resistance saving, and lightweight. [ABSTRACT FROM AUTHOR]

Summary: Thermal management of large‐scale Li‐ion battery packs is of great significance to their safety and life cycle, which would impact their applicability in electric vehicles. Of the many strategies developed for this purpose, indirect liquid cooling has already demonstrated quite high potentials in thermal regulation of such battery systems. In this study, a compact lightweight serpentine wavy channel configuration was chosen to construct an indirect liquid cooling system for a battery module of cylindrical Li‐ion cells. The serpentine channel has a number of six internal minichannels. Experimental test data were used to conduct a comprehensive thermal analysis to examine the highest temperature, the maximum temperature difference, and the heat accumulation percentages, and so forth within the battery pack. Results have revealed the ability of the cooling system to maintain the module temperature within appropriate working conditions for electric vehicle applications for most cycling tests including two driving cycles. Furthermore, the analysis insights raised by this study could be useful in understanding the cooling performance of the liquid‐based thermal management systems for electric vehicles. [ABSTRACT FROM AUTHOR]

Summary: Lithium‐ion batteries, as the only source of driving force for electric vehicles (EV), directly determine the vehicle's power performance, driving mileage, and working stability. The performance, safety, and longevity of lithium‐ion batteries are related to battery temperature. In this article, surface topography has been added in mini‐channel liquid cooling plate, the influence of different shapes, different heights, different diameters, and different numbers of surface topography on the cooling effect of mini‐channel liquid cooling plate were researched by using CFD method. This article revealed that the addition of surface topography in mini‐channel can affect the flow trajectory of coolant and improve the cooling capacity of the cold plate. When five cylindrical surface topography with a diameter of 10 mm and a height of 1.5 mm were added in each channel, the highest temperature of the battery can be suppressed to 42.01°C and the maximum temperature difference can reach 15.78°C under 3C discharge rate, compared with the smooth mini‐channel, decreased by 1.02°C and 0.85°C, respectively. [ABSTRACT FROM AUTHOR]

Summary: The uniformity of temperature distribution is the key factor in heat transfer rate of battery thermal management. In this paper, the battery thermal management using phase change material based on temperature equilibrium strategy have been proposed, in order to get the temperature distribution of battery more uniform. The effects of equilibrium strategy and Rayleigh number are studied. When the Rayleigh numbers are 2.9 × 104, 1.2 × 105, 1.1 × 106, and 4.9 × 108, the temperature SDs applying the equilibrium strategy are reduced by −1.9%, 1.2%, 32.3%, and 14.4%, respectively. Besides, the corresponding complete melting times are reduced by 0.97%, 1.96%, 4.76%, and 1.58%. The equilibrium factor in equilibrium strategy is considered as well. It is noted that increasing the equilibrium factor is able to get the more uniform temperature distribution, resulting in the faster melting rate. When the equilibrium factors are 1, 4, and 6, the complete melting times are reduced by 1.58%, 50.0%, and 51.4%, respectively, improving the thermal performance of battery thermal management. [ABSTRACT FROM AUTHOR]

Summary This article reports a recent study on a liquid cooling‐based battery thermal management system (BTMS) with a composite phase change material (CPCM). Both copper foam and expanded graphite were considered as the structural materials for the CPCM. The thermal behaviour of a lithium‐ion battery was experimental investigated first under different charge/discharge rates. A two‐dimensional model was then developed to examine the performance of the BTMS. For the copper foam‐based CPCM modelling, an enthalpy‐porosity approach was applied. The numerical modelling aimed to study the impacts of CPCM types and inlet velocity of heat transfer fluid on both the maximum battery temperature and temperature distribution under different current rates. Dimensional analyses of the results were performed, leading to the establishment of relationships of the Nusselt numbers and dimensionless temperature against the Fourier and Stefan numbers. [ABSTRACT FROM AUTHOR]

Summary: Battery thermal management system is critical to ensure the temperature of the battery pack in electric vehicles within a suitable range. In this study, the battery pack is cooled by the parallel mini‐channel cold plate (PMCP). The performance of the PMCPs with I‐type (PMCP I), Z‐type (PMCP Z), and U‐type flows (PMCP U) are studied using numerical method. Then, the edge width and convergence channel width of the three systems are designed. The cooling performance of the PMCPs is effectively improved after the structure design. Subsequently, the symmetrical system is constructed based on each PMCP. The numerical results show that the symmetrical systems achieve lower maximum temperature, smaller maximum temperature difference, and lower energy consumption. Among the three systems, the performance of the symmetrical PMCPs I and Z is similar and better than that of the symmetrical PMCP U. Finally, the dimensionless analysis is performed to explore the influences of various parameters on the final designed cold plate. The results indicate that the inlet cooling water temperature and heat flux density applied to the cold plate do not affect the structure of the final designed system. Moreover, the designed systems have good performance under different mass flow rates. Highlights: PMCPs with different flow patterns are applied in BTMS.Performance of PMCPs is improved through multi‐parameter structure design.The symmetrical systems are constructed for performance improvement.T0 and q0 do not affect the structure of the designed PMCP.ΔTmax and WP of designed PMCP are respectively reduced by at least 19% and 61%. [ABSTRACT FROM AUTHOR]

Summary: The power battery as an indispensable part of electric vehicle has attracted much attention in recent years. Among these, the lithium‐ion battery is the most important option due to the high energy density, good stability, and low discharge rate. However, the thermal safety problem of lithium‐ion battery cannot be ignored. Therefore, it is very necessary to explore an effective thermal management system for battery module. Here, a thermal silica cooling plate‐aluminate thermal plate (SCP‐ATP) coupling with forced convection air cooling system as a thermal management system is proposed for improving the cooling performance of pouch battery module. The results reveal that the heat dissipating performance and temperature uniformity of pouch battery module with SCP‐ATP are greatly improved compared with other thermal management systems. Moreover, the highest temperature can be controlled below 50°C, and the temperature differences can be maintained with 3°C when the SCP‐ATP coupling forced convection is utilized to enhance the heat transfer coefficient. Furthermore, considering the cooling effectiveness and consumption cost comprehensively, the optimal air velocity of the SCP‐ATP coupling forced convection cooling system is 9 m/s. In addition, the SCP‐ATP filling with different proportions of acetone has also been investigated for pouch battery module, indicating that 50% acetone exhibited a better heat transfer effect than the 30% one. Therefore, this research would provide a significant value in the design and optimization of thermal management systems for battery module. [ABSTRACT FROM AUTHOR]

Summary: With the latent heat, the phase change material (PCM) is widely used in battery thermal management (BTM) to control the temperature. In this paper, the porous medium is employed to enhance the heat transfer of PCM. The lattice Boltzmann model for PCM/porous medium in pore scale is considered, where the mesh system with porous medium (fixed point) is generated by quartet structure generation set (QSGS) method. The effects of the Rayleigh number and porosity on the heat transfer process in BTM are investigated. The results show that decreasing the porosity will accelerate the melting rate. When the porosities are 0.9, 0.8, 0.7, and 0.6, the total melting times are decreased by 23.7%, 43.3%, 58.0%, and 75.4%, compared with pure PCM. The heat is transferred through the high‐conductivity framework. The natural convection in the porous medium is weak, and the conduction is the dominated heat transfer. As a result, the area of solid–liquid interface will be increased, and the heat‐transferred rate is accelerated. However, when the Rayleigh number is raised to 105, applying the porous medium with porosity of 0.9 will increase the total melting time, resulted from the stronger natural convection of PCM. The present study is helpful for design of PCM/porous medium‐based BTM. [ABSTRACT FROM AUTHOR]

Summary: The reliable protection of personal safety and vehicle service security has aroused the rising attention on battery thermal safety issues. This poses ongoing challenges for battery thermal management (BTM) to improve the safety by constantly learning and adopting advanced technologies from thermal management to thermal safety control. On the basis of electrochemical, mechanical, and thermo‐kinetic characteristics of battery behavior evolution under operational conditions of normal and abnormal, BTM with enhanced safety cannot only guarantee the battery operation performance but also improve thermo‐safety behavior with the heat transfer intensifying method. Additionally, via effective measurements to detect and warn the battery behavior evolution characteristics, the combination of emergency cooling, fire extinguishing, and thermal barrier adopted in BTM with enhanced safety can effectively and sufficiently suppress battery thermal overheating and its propagation. As concluded, the synthesized integration of basic BTM and its safety‐enhanced treatment can ensure the optimal working temperature range and prevent thermal overheating from propagation. Thus, the BTM system with enhanced safety has been a promising research priority. This article provides a comprehensive review on BTM with enhanced safety aiming to promote the battery application with high energy density, security, and cyclic stability served for electrification and intelligentization of automobiles. In addition, the summary of relevant research status and key technology is dedicated to improving BTM thermo‐safe design innovation and collaborative optimization, to fit with the sustainable development needs of the long‐term mechanism of energy conservation and green‐energy vehicles marketization. [ABSTRACT FROM AUTHOR]

Summary: With the depletion of fossil fuels and the aggravation of environmental pollution, the research and development speed of electric vehicles has been accelerating, and the thermal management of battery pack has become increasingly important. This paper selects the electric vehicle battery pack with natural air cooling as the study subject, conducts simulation analysis of the heat dissipation performance of battery packs with and without vents. Then this paper researches on the influence of internal flow field and external flow field. Field synergy principle is used to analyze the effect of velocity field and temperature field amplitude. The results show the following: it is found that the maximum temperature rise and the internal maximum temperature difference of the battery pack with vents are reduced by about 23.1% and 19.9%, raising speed value can improve the heat dissipation performance, and raising temperature value can decrease the heat dissipation performance. Reasonable design of the vents can make the inner and outer flow field work synergistically to achieve the best cooling effect. Then the reference basis for the air cooling heat dissipation performance analysis of electric vehicle, battery pack structure arrangement, and air‐inlet and air‐outlet pattern choosing are offered. [ABSTRACT FROM AUTHOR]

Summary: Some potential safety risks for lithium ion battery such as overheating, combustion, and explosion occurred in practical application may cause accidents of electric vehicles. Phase change material (PCM)‐based thermal management system was demonstrated as a feasible approach. However, the batteries have to endure various environment and climate, which would not work normally under cold area. Especially when the surrounding temperature falls to below 10°C, which can bring about the energy and power of Li‐ion batteries rapidly reducing. In this study, a coupling heating strategy of the PCM‐based batteries module with 2 heat sheets at low temperature was proposed for batteries module and cannot only balance the temperature among different batteries in the module but also ensure to pre‐heat the batteries module at low temperature. The experiment displayed that 7% of EG in paraffin‐based composite PCMs was the best proportion for batteries module, considering both fluidity and thermal conductivity factors. In addition, the temperature difference of PCM‐based batteries module was 2.82°C, while that of the air‐based one was 14.49°C, which was 5 times more than former, exhibiting an excellent performance in balancing temperature uniformly, and was beneficial for prolonging the lifespan of batteries. The coupling heating strategy‐based PCM with heat sheets provided as an extremely promising technology for lithium batteries module at low temperature. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a passive technique is examined by adding an inlet plenum to reduce the maximum temperature and improve temperature uniformity in a simple battery pack. The inlet plenum changes the direction of the flow and dramatically reduces the issues of air recirculation and dead‐air regions between adjacent cells. The dimensions of the plenum and Reynolds number were optimized to enhance cooling and temperature uniformity at the cell and pack level. The results indicated that by increasing the Reynolds number to 7440, the maximum temperature decreased by 18.3% and the temperature uniformity increased 54.6%. However, there was no significant change in the maximum temperature and temperature uniformity beyond the Reynolds number of 7440. The developed battery pack achieved the desired temperature uniformity at the cell and pack level to less than 5°C. [ABSTRACT FROM AUTHOR]

To achieve safe, long lifetime, and high-performance lithium-ion batteries, a battery thermal management system (BTMS) is indispensable. This is especially required for enabling fast charging-discharging and in aggressive operating conditions. In this research, a new type of battery cooling system based on thermal silica plates has been designed for prismatic lithium-ion batteries. Experimental and simulations are combined to investigate the cooling capability of the BTMS associated to different number of cooling channels, flow rates, and flow directions while at different discharge C-rates. Results show that the maximum temperature reached within the battery decreases as the amount of thermal silica plates and liquid channels increases. The flow direction had no significant influence on the cooling capability. While the performance obviously improves with the increase in inlet flow rate, after a certain threshold, the gain reduces strongly so that it does not anymore justify the higher energy cost. Discharged at 3 C-rate, an inlet flow rate of 0.1 m/s was sufficient to efficiently cool down the system; discharged at 5 C-rate, the optimum inlet flow rate was 0.25 m/s. Simulations could accurately reproduce experimental results, allowing for an efficient design of the liquid-cooled BTMS. [ABSTRACT FROM AUTHOR]