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[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 discharge performance of lithium-ion batteries (LIBs) is severely degraded at low temperatures. The existing LIBs preheating systems face challenges including high costs and consumption of battery capacity. Therefore, this paper developed an innovative electrically-controlled crystallization electrode based on calcium chloride hexahydrate (CCH) (ECE-CCH) by melting-solidification method and devised an electrically-controlled phase change material (PCM) preheating system based on CCH (EPS-CCH) for LIBs. The stable supercooling and great heat storage/release properties of the CCH, as well as the excellent low-voltage electrically-controlled crystallization performance of ECE-CCH, enable EPS-CCH to achieve safe and controllable thermal management of LIBs at the optimal operating temperature. Under the premise of maintaining the stable supercooling and heat storage properties of CCH (50.67 wt% CaCl 2 solution), 48 wt% CaCl 2 solution was selected as the heat storage material (melting point: 31.5 °C, latent heat: 153.0 J /g). The ECE-CCH could release the latent heat of the supercooled CCH solution in <5 s at low DC voltages (1.0–2.0 V). 100-cycle experiments illustrated that ECE-CCH had good cycle stability and an optimal operating voltage range of 1.0–1.5 V. Finally, EPS-CCH was designed to achieve on-demand control of thermal management of LIBs at low temperatures. Compared to LIBs without EPS-CCH at 5 °C, LIBs with EPS-CCH exhibited a significantly increased discharge capacity of 14.27%, 11.35%, and 7.04% at discharge rates of 0.5C, 1.0C, and 1.5C, respectively. The research findings of the ECE-CCH and the EPS-CCH would promote the development of LIBs preheating technologies. • A novel electrically-controlled electrode based on calcium chloride hexahydrate (CCH) was developed. • The crystallization of supercooled CCH was electrically triggered by 1.5 V DC voltage. • The crystallization behavior of supercooled CCH was investigated in-depth. • The EPS-CCH achieved a smart thermal management of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

To address the bottleneck of easy leakage and low thermal conductivity of phase change materials (PCMs) for battery thermal management. Phase change composite (PCCs) with paraffin (PA) as the PCM, styrene ethylene butylene styrene (SEBS) as the supporting skeleton, and boron nitride (BN) as the thermally conductive filler were fabricated by the sacrificial template method. Compared with the composite prepared by melt-blending method, the thermal conductivity of PCC was improved by 27.6 % and the leakage rate was reduced by 82.4 % because the BN was rubbed with Na 2 SO 4 under the shear provided by internal mixer. As a result, the maximum temperature and maximum temperature difference of the battery pack with PCC cooling were 35.8 % and 62.5 % lower than those without PCC cooling at 2C discharge rate. In total, this work offers a strategy for improving the thermal conductivity and the leakage-proof ability of PCCs as well as for large-scale fabrication. [Display omitted] • The SEBS-BN@PA composites are prepared by the sacrificial template method. • The prepared composites have good leakage-proof ability and shape stability. • The composite has higher thermal conductivity than those prepared by melt-mixing method. • The composite presents excellent performances for battery thermal management. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing demand for electrical vehicles, which are more energy efficient and environmentally friendly than their traditional counterpart. One of the crucial aspects of electrical systems is energy storage. A promising option for energy storage is Lithium-ion batteries (LIBs) due to their high energy density, longer life cycles, and faster charging when compared to other batteries. The disadvantage of employing LIBs is that they are more difficult to maintain because they are more prone to failure, and they are greatly dependent on the system's thermal behavior, which has led to an emphasis in research on battery thermal management systems (BTMSs). The BTMS aims to address this issue by limiting the temperature fluctuation of the battery cells to maintain the average temperature within recommended limits throughout the charging and discharging processes. There has been a continuous interest in nanofluids and phase change materials (PCMs) because of their unique properties and their potential thermal application as a cooling medium for high-density batteries. Recent studies have aimed to use different active and passive methods with varying materials and cooling system geometries to achieve the highest possible thermal performance. The current review aims to outline the recent studies on thermal management systems for LIBs. Three main sections have been presented in this paper. The first section reviewed studies on nanofluids in different BTMSs, the other one highlighted techniques adopted to overcome the low thermal conductivity drawback in PCMs for BTMs, and the last one focuses on the effects of combining both cooling approaches. We believe that the present review paper provides useful information that could be a significant step toward developing high-performance BTMS. • A summary of the most recent research on BTMS of LIBs. • Nanofluids and PCM-based BTMS attract significant interest in LIBs. • PCM with carbon additives enhance LIB pack temperature uniformity. • Incorporation of fins has demonstrated effectiveness in improving BTMS performance. • Metal foams with PCMs enhance BTMS performance via improved thermal conductivity. [ABSTRACT FROM AUTHOR]

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

Phase change material (PCM) is widely adopted to construct integrated battery thermal management systems (BTMSs) for all climates. However, integrated BTMSs in cylindrical battery modules remain arduous challenges due to the compact/massive cuboid-shaped PCM module and the curved surface of the cells. Herein, we propose a novel all-climate BTMS integrating units-assembled composite PCM (CPCM) module with force air convection. The CPCM module assembled by sleeve-like CPCM units provides developed airflow channels and enlarged heat transfer surface from 1.17 × 10−3 to 3.63 × 10−3 m2 for enhancing convective heat transfer. Consequently, compared to conventional cuboid-shaped module, the thermal resistance of the units-assembled module is remarkably reduced by 52.0% and 60.1%, and the heat flux is enhanced by 7 times under both cooling and preheating modes. In cooling tests, this BTMS demonstrates superior performance by controlling the temperature and temperature difference below 40.30 and 2.80 °C at 3-C discharge, respectively. In preheating tests, it effectively preheats the battery module from 0 to 10 °C in 302 s with a low temperature difference of 3.82 °C. Furthermore, this units-assembled CPCM module saves 53.8 wt% of the CPCM dosage, and thus the energy density of the battery module is increased from 75.6 to 94.4 Wh·kg−1. • All-climate BTMS integrates units-assembled CPCM module with force air convection. • Units-assembled CPCM module provides developed internal structure for heat transfer. • Thermal resistance of CPCM module is reduced, and heat flux is enhanced by 7 times. • BTMS shows superior cooling, preheating and heat-preservation performances. • BTMS reduces CPCM module weight, increasing the energy density of battery module. [ABSTRACT FROM AUTHOR]

The use of a hybrid cooling system, which combines phase change material (PCM) and liquid channels, has been extensively researched to mitigate the risk of battery thermal runaway. However, the existing studies on hybrid cooling systems have overlooked the impact of buoyancy-driven natural convection in PCM. This results in a uniform flow rate allocation among liquid channels, leading to inadequate heat dissipation performance. To this end, this paper proposed a prediction-informed adaptive flow rate allocation strategy for the hybrid cooling system considering natural convection in PCM. First, a novel thermal runaway model was developed, followed by a PCM model that considers natural convection. Then, the proposed strategy utilized Bi-directional Long Short-Term Memory (Bi-LSTM) to predict the outlet temperature, which represents the cooling demand. The flow rate was regulated based on the predicted temperature to avoid an initial flow rate of 0 in the liquid channel and achieve a timely response. The results showed that the proposed strategy extended the thermal runaway propagation interval by 60.6% (85.9 s) and reduced the total flow rate by 31.7%. This strategy significantly enhanced the hybrid cooling system's performance, without increasing the parasitic energy or reducing the battery pack's energy density. • Prediction-informed strategy to enhance hybrid cooling systems' performance. • Adaptive flow rate regulation for hybrid cooling systems considering natural convection. • Novel coupled electrochemical–thermal model for thermal runaway analysis. [ABSTRACT FROM AUTHOR]

• Developed and analyzed a novel hybrid battery pack thermal management system. • Incorporated a novel three-stage cooling strategy into the thermal management system. • Latent heat of PCM effectively extracts heat from the cylindrical Li-ion cells. • Secondary coolants increase the overall heat transfer coefficient of PCM. This paper introduces a novel hybrid thermal management concept, which use secondary coolants (air and water) to extract heat from a phase change material (paraffin), resulting in increased heat extraction capability of the paraffin and improvement the overall thermal performance of the battery module. This concept was analyzed using experimental and numerical studies. The experimental studies were conducted to obtain the temperature and heat flux profiles of the battery module. The numerical model is developed and validated using the experimental data obtained. The outcome of the study showed that the battery module temperature reached the phase change temperature threshold of the PCM in the fifth discharge cycle, and the through the use of latent heat the battery module temperature was maintained between 42 and 44 °C. Additionally, the thermal uniformity started to increase once the PCM started to change and the PCM utilization was ∼2.3 % after seven discharge cycles. Therefore, the proposed thermal management concept for the battery module can sustain the thermal environment needed for effective operation of the Lithium-ion batteries. [ABSTRACT FROM AUTHOR]

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

The era of electric mobility has started, and petrol/diesel vehicles are being replaced by electric vehicles (EVs). The phase change material (PCM) is a trending field of research in its application of energy storage and thermal management. PCM-based thermal management method is found to be quite simple and effective for battery packs. However, its commercialization is difficult due to its low thermal conductivity and extra weight addition to the battery pack. Hence, the present research focuses on the battery performance with PCM. The experimental setup for a 48V, 25Ah battery pack is developed, and its performance is explored with and without PCM. The numerical model for same sized battery pack is developed, and validated with experimental results. The major objective of the present research is to find the optimal gap between two battery cells so that a sufficient amount of PCM can be filled inside the battery pack. Initially, inline and staggered cell arrangements are examined, and no significant difference in thermal performance is found. Further, cell spacing of 5 mm, 3 mm, and 1 mm are examined, and maximum temperature and temperature difference are compared along with the weight and volume of the battery pack. For a single charging process, 1 mm cell spacing is found sufficient, considering the weight of the battery pack and thermal performance. However, with 1 mm cell spacing, temperature increases significantly after each charging and discharging. At the same time, 3 mm and 5 mm are found as feasible solutions considering single and double charging-discharging cycles, respectively. 3 mm cell spacing is better option when weight is a critical issue, while 5 mm cell spacing is better when thermal performance is a critical issue. The current study offers guidance in the advancement of battery packs, particularly in cases where space constraints are a concern. • The research focuses on utilization of optimal amount of PCM. • The battery charging experiments are carried out on 48V, 25Ah battery pack. • PCM OM42 reduced battery temperature by 18 %. • The inline and staggered arrangements are found equally effective. • 3 mm cell spacing is found sufficient with limited weight increment. [ABSTRACT FROM AUTHOR]

• High-stable CPCM for battery thermal management is prepared via one-pot strategy. • 3D nano-framework is in-situ constructed to obtain high shape stability of CPCM. • Nano-framework stacks into a developed mesoporous structure to suppress leakage. • The obtained CPCM shows outstanding cooling performance for the battery module. • No leakage trace is detected on the battery module during accelerated aging tests. Mainstream phase change material (PCM) for the thermal management of battery modules has been suffering from the leakage issue due to the weak capillary condensation from its micron-scaled polymer framework. Therefore, in this work, we design a high-stable and leakage-proof composite PCM (CPCM) by in-situ constructing a nano-scaled resorcinol-furfural polymer framework (RF-PF) in PCM via a one-pot strategy. Compared to classical micron-scaled framework of epoxy resin, the nano-scaled RF-PF stacks into a three-dimensionally mesoporous structure, and thus provides a much more intensive adsorbability towards PCM to prevent leakage. The mass retention rate of the RF-PF-based CPCM (RF-CPCM) during the leakage tests is up to 99.84 wt%. Combining with the suitable thermo-physical properties including a phase change enthalpy of 107.18 J g−1, phase change temperature region of 40– ∼ 55 °C and thermal conductivity of 1.58 W m−1 K−1, the RF-CPCM demonstrates effective and stable thermal management performances towards the pouch and cylindrical battery modules. For example, the temperature of the pouch battery module can be controlled below 41.15, 44.16 and 46.82 °C during 0.5-C, 1-C and 2-C discharges, respectively. During the accelerated aging test, the leakage trace appearing on the traditional CPCM module, is effectively overcome in the RF-CPCM module. [ABSTRACT FROM AUTHOR]

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

In order to improve the heat dissipation performance of lithium-ion batteries in hot climate, a coupled heat dissipation model including different air inlet and air outlet arrangements and PCM thicknesses was established by extracting cooling air from a vehicle air-conditioner. At the condition of the fixed PCM thickness, the effects of air inlet and air outlet arrangement on heat dissipation performance (HDP) of battery pack were researched, and the results indicate that case 5 is the optimal choice because of the low energy consumption and good HDP. The results of PCM thickness on HDP of battery pack be investigated through catastrophe theory analysis method. Thus, the results reveal that case 8 has highest evaluation value 0.97536 of the heat dissipation level of the battery pack among them. Based on the above results, four cases had been investigated to pursue the lower temperature difference of battery pack, and the results indicate that case 10 is the optimal choice, because of the lower energy consumption and temperature difference. • A coupled heat dissipation model including different air inlet and air outlet arrangements and PCM thicknesses was established. • Effects of different conditions on the heat dissipation of the battery pack is studied. • Catastrophe model was used to evaluate the heat dissipation level of the battery pack. [ABSTRACT FROM AUTHOR]

Abstract Thermal management system is essential for lithium-ion batteries in electric vehicle to control operating temperature and temperature differences. Phase change material (PCM) is commonly used in the study of battery thermal management system (BTMS). However, with low thermal conductivity, pure PCM is not sufficient for transferring the heat generated from battery cells. To resolve this problem, the thermal conductivity of PCM was enhanced using cooper foam. Active liquid cooling was also combined with copper foam/paraffin composite phase change material (CPCM) to provide extra cooling ability. The cooling tube is evenly distributed in the copper foam, and a coolant is circulated through the tube. The copper foam has a porosity of 98% and pore size of 20 ppi, and the paraffin has a melting point of 25 °C. A three-dimensional numerical model for the BTMS based on PCM and active liquid cooling was performed using ANYSYS FLUENT. The impact of the velocity of liquid inlet and material module on the BTMS was examined regarding the evolution of thermal management performance. A significant improvement of thermal management using CPCM and liquid cooling was observed with 14 °C of lower cell temperature. [ABSTRACT FROM AUTHOR]

As an advanced battery thermal management method, phase change material (PCM) cooling technology is highly desirable but remains significant challenges, considering the instability of the PCM module, including PCM leakage, volume changes and inhomogeneity of the whole module during the repeated melting/solidifying processes. Herein, we develop a kind of nanosilica (NS)-enhanced composite PCM (CPCM-NS) with outstanding anti-leakage and anti-volume-change performances for power battery thermal management. The NS presents numerous nanoscale pores ranging from 30 to 100 nm, which can adsorb liquid phase paraffin (PA) intensively, thus preventing the migration and leakage of liquid PA, increasing the homogeneity and reliving the volume change phenomenon of the module to a great extent. As a result, these enhanced properties of CPCM-NS endow the obtained battery module with much better cooling efficiency and durability. For instance, the maximum temperatures of CPCM-NS with 5.5 wt% of NS are 1.6, 2.4, 4.5, 5.3 and 5.9 °C lower than those of CPCM without NS at the 1st, 2nd, 4th, 6th and 8th cycle charge/discharge cycle, respectively, and this temperature difference remains stable at 6.22 ± 0.05 °C during the subsequent cycles. [ABSTRACT FROM AUTHOR]

A passive thermal management system using copper metal foam saturated with phase change materials is designed for LiFePO 4 battery pack. Copper metal foam is aimed to enhance low thermal conductivity of PCM and improve temperature uniformity of the battery pack. The thermal efficiency of the system is experimentally investigated and compared with two dissipation patterns of air cooling and pure PCM. The results show that the dissipation pattern of the foam-PCM composite can significantly reduce the battery’s surface temperature compared with the other two patterns. Moreover, the foam-PCM composite can bring the battery pack a better temperature uniformity, especially during the higher discharge rate. [ABSTRACT FROM AUTHOR]

Thermal management is a crucial strategy that needs to be carefully considered for lithium-ion batteries under extreme operating conditions. One promising approach is the use of phase change material (PCM), which can bring benefits such as passively thermal buffering and extending lifespan. In this paper, a paraffin/expanded graphite (EG) composites based battery module (PCM module), as well as the two dimensional thermal model is proposed. The effects of different EG mass fractions associated with different phase change enthalpy and thermal conductivity are investigated firstly under high-rate discharge condition. The results show that an optimal mass fraction of EG is needed to achieve the best thermal performance and the EG mass fraction of 15–20% is recommended to be used for battery thermal management. In order to further improve the overall performance, we also design a novel pyrolytic graphite sheets (PGS)-enhanced paraffin/EG composites based battery module (PCM/PGS module). EG with porous structure can create the primary thermal conductive network for PCM to increase the heat absorption rate. PGS forms the secondary thermal conductive network for the module to improve the whole thermal homogeneity. As a result, the as-designed PCM/PGS module presents much better heat dissipation performance and temperature uniformity compared with the PCM module during discharge–charge cycles. Also, the introduction of PGS is beneficial for thermal fluctuations and energy saving, for instance, the thermal performance of PCM/PGS module with a convective heat transfer coefficient of 50 W m −2 K −1 is comparable to PCM module with 200 W m −2 K −1 . In the case of failure mode, to achieve the prevention of thermal runaway propagation, the spacing between cells for PCM module is up to 14 mm. However, the use of PGS lowers the spacing (i.e. less composite PCM consumption) by a decreasing rate of ∼71.4% in comparison with PCM module. [ABSTRACT FROM AUTHOR]

In this paper, a heat pipe-assisted phase change material (PCM) based battery thermal management (BTM) system is designed to fulfill the comprehensive energy utilization for electric vehicles and hybrid electric vehicles. Combining the large heat storage capacity of the PCM with the excellent cooling effect of heat pipe, the as-constructed heat pipe-assisted PCM based BTM is feasible and effective with a relatively longer operation time and more suitable temperature. The experimental results show that the temperature maldistribution of battery module can be influenced by heat pipes when they are activated under high discharge rates of the batteries. Moreover, with forced air convection, the highest temperature could be controlled below 50 °C even under the highest discharge rate of 5C and a more stable and lower temperature fluctuation is obtained under cycling conditions. Meanwhile, the effectiveness of further increasing air velocity (i.e., more fan power consumption) is limited when the highest temperature continues to reduce at a lower rate due to the phase transition process of PCM. These results are expected to provide insights into the design and optimization of BTM systems. [ABSTRACT FROM AUTHOR]

The battery thermal management technology is vital for the development of new energy vehicles. In order to understand the performance of the phase change material/heat pipes (PCM/HP) coupled thermal management system for cylindrical power battery, an PCM/HP coupled BTM module was designed and tested experimentally in detail. The results showed that the effect of temperature control based on PCM is improved comparing to air-based BTM under natural convection. The maximum temperature of PCM/HP coupled BTM can be controlled below 50 °C for longer time than those of the air-based case and PCM-based case under the same conditions. The temperature difference can be reduced about 33.6% through filling PCM and it can progress a decline of 28.9% further through embedding HP into the PCM. The maximum temperature difference of PCM/HP coupled BTM can be controlled below 5 °C for longer time than those of the two other cases, air-based BTM and PCM-based BTM. It is almost the same in the first 620 s under different velocities, which are all less than 5 °C. [ABSTRACT FROM AUTHOR]

The power and energy densities of battery will decrease at cold temperature and the heat preservation is necessary to keep the working temperature. In this paper, the lattice Boltzmann model for phase change material based battery thermal management cold temperature is constructed and the effects of thermal conductivity, latent heat and environmental temperature have been considered. The results show that with the latent heat of phase change material (PCM), the temperature of battery decreases slowly and the temperature distribution can be guaranteed. However, once the PCM adjacent to the interface of battery and PCM, the temperature of battery drops faster and the temperature standard deviation rises sharply. Besides, the lower thermal conductivity, greater latent heat and higher environmental temperature are able to slow down the solidification process of PCM and keeps the temperature of battery. However, with larger latent heat of PCM, the battery temperature distribution gets more non-uniform, which is able to decrease the cycle life of battery. [ABSTRACT FROM AUTHOR]

In this study, a hybrid liquid cold plate design containing Z-type parallel cooling channel and PCM/aluminum foam composite, in conjunction with a novel delayed cooling strategy, is proposed to provide a compact, lightweight, and energy efficient solution for battery thermal management systems (BTMSs). A total of nine different cold plate designs, including one baseline cold plate without PCM composite and eight hybrid cold plates containing PCM composite, are analyzed systematically to demonstrate the superior cooling performance of the proposed cooling design. Specifically, the average temperature of battery surface and total power consumption performance of each design are analyzed and compared at a battery discharging rate of 1C under both continuous and delayed cooling schemes. Subsequently, two selected designs with superior cooling performance as well as the baseline cold plate are further investigated to discuss the effectiveness of hybrid liquid cold plates for cooling batteries at high discharge rates. The results show that the optimum hybrid cold plate design, which only weighs half of the baseline cold plate, can provide more than 50% reduction in the total pumping power while achieving the same cooling performance (i.e., with the average battery temperature controlled within 40 °C) compared with the baseline cold plate at battery discharging rates of 1C, 2C and 3C. These results can potentially provide important guidance to the design of advanced cooling systems for lithium-ion batteries. • A compact and lightweight battery thermal management system is proposed. • A delayed cooling strategy is proposed and analyzed. • Cooling performances were compared between different designs numerically. • Optimum cooling system allows >50% reduction in power consumption and weight. [ABSTRACT FROM AUTHOR]

As an important method for battery thermal management, traditional phase change material (PCM) technology is facing challenges due to the relatively low thermal conductivity, weak skeleton strength and/or leakage phenomenon of PCM. Herein we develop a copper mesh (CM)-enhanced paraffin (PA)/expanded graphite (EG) composite as a composite PCM for battery thermal management. EG with porous structure can absorb liquid phase PA, preventing PA leakage. CM acts as a skeleton to further enhance both the thermal conductivity and strength of the whole module. As a result, the as-constructed CM enhanced PCM of PA/EG plate (PCMP) presents much better heat dissipation performance and temperature uniformity compared to PCMP without CM, especially in harsh working conditions. Moreover, with forced air convection, copper fins exposed from the composite may play a crucial role in not only heat dissipation, but also disturbing the air flow, and thus further strengthen the heat transfer capability. [ABSTRACT FROM AUTHOR]

• Composite PCM is designed by in-situ constructing phase changeable framework in PEG. • The novel composite PCM possesses dual phase change temperature regions (PCTRs). • The two PCTRs are precisely tailored at 31.7–42.1 ℃ and 42.1–51.2 ℃, respectively. • The lower PCTR ensures suitable working temperature for battery at normal operation. • The higher PCTR prevents thermal hazards of battery under high ambient temperature. The phase change material (PCM)-based battery thermal management technology still remains a contradiction of guaranteeing a suitable operating temperature (20–40 ℃) of the batteries under regular working conditions, while avoiding the malfunction of the PCM under high ambient temperature (>40 ℃). Therefore, a novel composite PCM (CPCM) possessing dual phase change temperature regions (PCTRs) is designed herein by in-situ constructing a phase-changeable polymer (PCP) framework in the polyethylene glycol (PEG)/expanded graphite (EG) slurry. As prepared, the lower PCTR at 31.7–42.1 ℃ from the PCP framework provides a latent heat of 35.0 J g−1, while the higher PCTR at 42.1–51.2 ℃ from the PEG offers a latent heat of 68.3 J g−1. Additionally, the nanoscaled PCP framework strongly adsorbs the PEG, preventing the leakage phenomenon (mass loss < 1%), and the uniformly dispersed EG endows the CPCM with a high thermal conductivity of 1.98 W m−1 K−1. In consequence, under the normal ambient temperature of 25 ℃, the lower PCTR effectively keeps the battery module operating within the suitable temperature range of 25.9–34.9 ℃ and with a low temperature difference (ΔT) of 2.4 ℃ at the discharge rate of 1C. For comparison, the battery module adopting classical CPCM with a single PCTR at 40.9–55.1 ℃ demonstrates a much higher temperature range and maximum ΔT at 28.0–40.9 ℃ and 4.8 ℃, respectively. Under the high ambient temperature of 40 ℃, the higher PCTR starts to work like the single PCTR of traditional CPCMs, and controls the T max and ΔT of the module below 49.2 and 2.2 ℃ at the discharge rate of 1C, respectively, preventing thermal hazards. [ABSTRACT FROM AUTHOR]

A kind of new hybrid thermal management system combining phase change materials with a series of liquid cooling is designed. The characteristics of the temperature change is studied experimentally and numerically when the ambient temperature is 25 °C to 40 °C. The results indicate that the temperature of phase change cooling system is reduced by 44.2%, 30.1% and 5.4%, respectively, compared with air cooling system, liquid cooling system and pure phase change material cooling system. To further enhance heat transfer, copper fins are added around the battery, the results shows that the maximum longitudinal difference of the battery temperature decreased by 69.7%. The research of this paper provides a theoretical basis for the thermal characteristics of hybrid cooling system and a design method with higher cooling efficiency and better temperature uniformity for the design of power battery thermal management system. • A new hybrid thermal management system combining phase change materials with liquid cooling is designed. • The simulation results are in good agreement with the experimental results. • The design structure of BTMS is optimized and validated again with experiments and simulation. • Hybrid thermal management system improves the temperature uniformity of the battery pack. [ABSTRACT FROM AUTHOR]

• A novel CPCM with antileakage property for battery thermal management is prepared. • A nanoscale framework is constructed to replace micron-scale framework in CPCM. • The nanoscale framework stacks into a developed mesoporous structure to adsorb PEG. • The obtained CPCM presents excellent antileakage property and thermal stability. • The obtained CPCM shows outstanding cooling performance for the battery module. To solve the leakage issue of phase change material (PCM)-based battery thermal management (BTM) technology, a novel composite PCM (CPCM) is prepared herein by constructing a nanoscale resorcinol–formaldehyde (RF) framework to replace the classical micron-scale polymer framework. The three-dimensional (3D) nanoscale RF framework stacks into a 3D continuous mesoporous structure with a pore size of ∼ 30 nm and thereby results in intensive adsorbability toward polyethylene glycol, delivering an excellent antileakage property under long-term heat treatment up to 120 °C. The obtained CPCM possesses a thermal conductivity, latent heat and phase change temperature region of 1.26 W·m−1·K−1, 103.13 J·g−1 and 35–60 °C, respectively. Consequently, superior temperature-control performances for the battery module can be obtained. Even at high discharge rates of 2 and 3C for 10 cycles, the maximum temperature and temperature difference can be maintained below 39.7 and 2.4 °C and 41.7 and 2.3 °C, respectively. [ABSTRACT FROM AUTHOR]

Battery thermal management (BTM) plays a significant role in the safety and reliability of autonomous underwater vehicles (AUV) at higher speeds. In this study, a nanoparticle/phase change material (nano-PCM) composite is proposed for the BTM of an AUV. The effects of nanoparticle loading percentage (φ = 5, 10, and 15%) and nanoparticle filling range (α = 30, 60, 90, and 120°) on the battery temperature and PCM melting were investigated numerically. Two criteria for the dimensionless temperature control performance (TCP) factor and dimensionless heat storage performance (HSP) factor were used to evaluate the influence of various variables on the BTM performance. The results show that increasing the nanoparticle loading percentage improves the effective thermal conductivity of the PCM but reduces the overall effective latent heat. An optimal nanoparticle filling range of α = 60° is recommended to accelerate the overall melting rate of the PCM. Compared with those of the pure PCM-based BTM, the TCP rate and TCP density are enhanced by 14.56% and 26.75%, respectively, at α = 60°. The HSP rate increases by 2.84% but the HSP density reduces by 11.85% at α = 60°. These findings can provide a reference for the accurate design of nano-PCM composites for the BTM of AUVs. [ABSTRACT FROM AUTHOR]

Lithium-ion (Li-ion) battery cooling using a phase change material (PCM)/compressed expanded natural graphite (CENG) composite is investigated, for a cylindrical battery cell and for a battery module scale. An electrochemistry model (average model) is coupled to the thermal model, with the addition of a one-dimensional model for the solution and solid diffusion using the nodal network method. The analysis of the temperature distribution of the battery module scale has shown that a two-dimensional model is sufficient to describe the transient temperature rise. In consequence, a two-dimensional cell-centred finite volume code for unstructured meshes is developed with additions of the electrochemistry and phase change. This two-dimensional thermal model is used to investigate a new and usual battery module configurations cooled by PCM/CENG at different discharge rates. The comparison of both configurations with a constant source term and heat generation based on the electrochemistry model showed the superiority of the new design. In this study, comparisons between the predictions from different analytical and computational tools as well as open-source packages were carried out, and close agreements have been observed. [ABSTRACT FROM AUTHOR]

With the large latent heat and low cost, the paraffin has been widely used in battery thermal management (BTM) system to improve the efficiency and cycling life of power battery. The numerical model of paraffin melting in a cavity has been established, and the effects on the solid-liquid phase change process have been investigated for the purpose of enhancing the heat transfer performance of paraffin-based BTM system. The results showed that the location of the heating wall had great effects on the melting process. The paraffin in the cavity melted most quickly when the heating wall located at the bottom. Furthermore, the effects of thermal conductivity and the velocity of the slip wall have been considered. The gradient of liquid fraction increased with the increase in thermal conductivity, and the melting process could be accelerated or delayed by the slip wall with different velocity. [ABSTRACT FROM AUTHOR]

In order to extend the cycle life of power battery pack within electric vehicle, a phase change material (PCM)/mini-channel coupled power battery thermal management (BTM) system, as well as the three-dimensional battery thermal model, was designed in this paper. The effect of various influencing factors, especially mass flow rate of water, phase change temperature and thermal conductivity of PCM, were investigated numerically. The results showed that the liquid volume fraction of PCM was greatly influenced by the thermal conductivity and the phase change temperature of PCM. The increasing number of channels results in a decrease of the maximum temperature ( T Max ) and maximum temperature difference (Δ T ) of battery packs. The optimal phase change temperature and thermal conductivity of PCM were 308.15 K and 0.6 W m −1 K −1 respectively when the number of channel was eight and the mass flow rate was 8 × 10 −4 kg s −1 . Moreover, a maximum temperature of 320.6 K was predicted for the PCM/mini-channel coupled BTM system, while a maximum temperature of 335.4 K was predicted for the PCM-based BTM system. Additionally, the PCM/mini-channel coupled BTM system presented more effective thermal performance and the research will be a clear indicator for the design of the PCM/liquid coupled BTM system. [ABSTRACT FROM AUTHOR]

The thermal management of a cylindrical battery cell by a phase change material (PCM)/compressed expanded natural graphite (CENG) is investigated in this study. The transient thermal behaviour of both the battery and the PCM/CENG is described with a simplified one-dimensional model taking into account the physical and phase change properties of the PCM/CENG composite. The 1D analytical/computational model yielded nearly identical results to the three-dimensional simulation results for various cooling strategies. Therefore, the 1D model is sufficient to describe the transient behaviour of the battery cooled by a PCM/CENG composite. Moreover, the maximum temperature reached by the PCM/CENG cooling strategy is much lower than that by the forced convection in the same configuration. In the test case studied, the PCM showed superior transient characteristics to forced convection cooling. The PCM cooling is able to maintain a lower maximum temperature during the melting process and to extend the transient time for temperature rise. Furthermore, the graphite-matrix bulk density is identified as an important parameter for optimising the PCM/CENG cooling strategy. [ABSTRACT FROM AUTHOR]

The present study introduces a novel fin–Phase Change Material (PCM)–Expanded Graphite (EG) composite for better thermal management of a Panasonic NCR18650BD battery at discharge rates higher than its maximum discharge limit 2C. Fins and EG are augmented with PCM to enhance its effective thermal conductivity. Initially, the electrical and thermal behaviors of the battery are simulated for 0.5, 1, and 2C discharge rates using the Newman P2D model, and these are validated against in-house experiments. Following this, the heat generation profiles are estimated from the numerical model to mimic the battery with a heater in the experiments conducted to propose an effective thermal management system for 2, 3, and 4C discharge rates. Three heat sinks, one sans fins, and the other two with 130 and 260 fins, respectively, are considered to perform experiments. Phase Change Material (PCM) named Eicosane (Ei) with an addition of 0, 10, 20, 25, and 30% weight fractions of EG is filled in the heat sinks to study the effect of composite PCM on the thermal regulation of the battery. The heat sink having 260 fins filled with 70% Ei - 30% EG composite outperforms the other heat sinks considered in this study by recording lower temperatures to the extent of 17.5, 20.5, and 22.7 °C than a plain heat sink filled with 100% Eicosane for discharge rates 2, 3, and 4C, respectively. Furthermore, with the addition of 30% EG by volume, the maximum thermal performance of heat sink having 130 fins surpasses the heat sink having 260 fins filled with pure Eicosane by recording 1.3, 0.5, and 1.5 °C lower temperatures for discharge rates 2, 3, and 4C, respectively. In view of this, a possible engineering solution is to employ a simple heat sink, having fewer fins filled with PCM–EG composite instead of intricate heat sinks, having more fins filled only with the baseline PCM, to overcome the design difficulties and manufacturing costs. • Introduced fin–PCM–EG composite heat sink for thermal management of Li-ion batteries. • Newman P2D model is used to calculate the heat generation for 2, 3, and 4C rates. • Compared performance of different heat sinks for 2, 3, and 4C rates experimentally. • Heat sink with 260 fins and 70% Ei - 30% EG outperforms all other combinations. • Addition of EG helps to propose a less intricate and more efficient heat sink. [ABSTRACT FROM AUTHOR]

In this study, a novel thermally induced flexible phase change material (PCM), which consists of an elastomeric block copolymer called styrene-b-ethylene-co-butylene-b-styrene triblock copolymer (SEBS), paraffin (PA) and expanded graphite (EG), is successfully prepared. Here, SEBS and EG serve as a supporting material and a thermal enhanced component. The effects related to latent heat, thermal stability, thermal conductivity and shape stability of different SEBS mass fractions are investigated and the test results reveal the good thermal performance of the PA/SEBS/EG blends. Besides, the further rheological analysis points out that the property of shape stability and thermal induced flexibility are based on the physical crosslinking mechanism between SEBS and PA. As a result, PA/SEBS/EG composite considerably reduces thermal contact resistance due to narrower gap, endowing the battery module with much better heat dissipation efficiency and temperature uniformity. The 3 C discharge of the battery module test shows that the maximum temperature of battery module using PA/SEBS/EG blend is effectively controlled within 42.2 °C, while the maximum temperature difference is below the safety threshold of 5 °C during the 5-cycling discharge and charge tests. • A novel CPCM with thermally induced flexibility and shape stability is proposed. • Detailed analysis of the thermophysical properties has been conducted. • The thermally induced flexibility can obviously reduce thermal contact resistance. • Flexible CPCM exhibits excellent heat dissipation performance. [ABSTRACT FROM AUTHOR]

Highlights: [•] Performances of a PCM-based battery thermal management system are investigated. [•] The PCM with the optimal thermo-physical properties is presented. [•] Numerical simulation is carried out and results fit with experimental data well. [Copyright &y& Elsevier]

Majority existing organic composite phase change materials (CPCMs) are flammable that result in thermal hazards such as fire and explosions in battery modules. Furthermore, the performance of PCM-based battery modules in extreme conditions like thermal runaway has not been studied adequately. In this study, a tubular CPCM-cell structure is designed using physically flame-retardant-modified CPCMs, and a series of experiments on the CPCMs with/without real cells is conducted with calorimeter tests and SEM analysis on morphology structure. First, the calorimeter tests and comparison on the heat release rate (HRR) are conducted on the CPCMs with and without flame retardant additives. Results show that the addition of Al(OH) 3 reduced the HRR from 242.5 to 204.4 kW/m2 with 15 wt% additives. Besides, the analysis of the mitigating performances of structure-enhanced tubular module and traditional cuboid module with real batteries is conducted. A factor of safety (FOS) parameter is defined to evaluate the safety degree of thermal runaway domino with energy density. The FOS of blank, CPCM–0 C , and CPCM–15 C modules are 0, 3.59, and 16.67, respectively, while that of CPCM-15 T reaches 21.01, indicating a significant improvement on mitigating effects by structure enhancement compared to adding flame retardant additives. This study brings novelty in the design of PCM-based battery modules, particularly from the thermal safety prospect. • An optimized tubular module using modified CPCM is designed to reduce hazard risk. • Bottleneck issue is solved by structure enhancement without reducing energy density. • Effect of flame retardant additives on thermal hazards is tested with/without cells. • Mitigation of tubular unit with air-flow-channel on heat propagation is tested. • Evaluation of battery modules are conducted from two aspects simultaneously. [ABSTRACT FROM AUTHOR]

• TPC-et skeleton is introduced to realize the room-temperature-flexibility of FCPCM. • TPC-FCPCM shows great applicability to various kinds of cells and battery modules. • TPC-FCPCM shows outstanding cooling performance compared to classical rigid CPCM. • TPC-FCPCM is favorable to alleviating the compressive stress in actual application. Flexible composite phase change materials (CPCMs) can minimize the thermal contact resistance in battery thermal management. However, these "thermally-induced" flexible CPCMs only present well-flexibility above the phase change temperature, which is unfavorable to the flexible assembly of the cells and battery modules with variable specifications. Herein, a kind of flexible CPCM with well-retained flexibility in a wide temperature range is prepared by carefully selecting a copolyester thermoplastic elastomer with polyether soft segment (TPC-et) to replace the conventional olefin block copolymer (OBC) skeleton. The internal rotation resistance of the ether bond in TPC-et is much lower than that of the C–C bond in OBC, thus giving rise to a better flexibility in room and low temperatures from 20 to −5 ℃. Combining the room-temperature-flexibility with the high thermal conductivity of 1.64 W m−1 K−1, enough latent heat of 102 J g−1 and suitable phase change region of 40–50 ℃, the obtained TPC-et based flexible CPCM shows outstanding applicability and cooling performance to various cells and battery modules through facile installations. The maximum temperature of the cylindrical, prismatic and pouch battery modules with TPC-et based CPCM is 51.5, 42.1 and 50.0 ℃, respectively, 4.0, 3.9 and 5.4 ℃ lower than the modules using rigid CPCM, respectively. [ABSTRACT FROM AUTHOR]

Phase change materials, as smart, ideal latent heat storage, and passive technology, have become the promising option for thermal management. However, the melting leakage, poor mechanical property, and intrinsic low thermal conductivity are long-standing bottlenecks for practical applications. In this study, a synergetic method is proposed to fabricate phase change composites with excellent shape stability, flexible property, and high thermal conductivity. Here, paraffin is used as thermal energy storage material, styrene-ethylene-propylene-styrene served as supporting material provides a cross-linked network to restrict paraffin molecular and endow the composite with thermal-induced flexibility, and expanded graphite with lamellar structure constructs an interconnected thermally network. The thermal conductivities of composites reach up to 2.671–10.019 W m−1 K−1 with EG loading of 5–30 wt%. Simultaneously, the phase transition enthalpy is measured as high as 155.4–211.9 kJ kg−1, indicating that the composites have good thermal properties. In addition, the composites exhibit superior thermal management behavior by controlling the operating temperature of battery to below 50 °C under normal discharge-charge and dynamic stress test cycles. Therefore, this work offers a convenient and efficient method to synthesize scalable form-stable composite with promising performance for battery thermal management and other advanced thermal management applications. • A ternary form-stable composites is fabricated through blending and impregnation method. • Styrene-ethylene-propylene-styrene restricts the leakage of liquid paraffin and endow flexibility for composite. • The expanded graphite shows long-chain structure and constructs thermally conductive path in composite. • The resultant composites exhibit enhanced thermal conductivity in the range of 2.671–10.019 W m−1 K−1. • The thermal management performance of composite is evaluated under normal and dynamic battery experiments. [ABSTRACT FROM AUTHOR]

• Low-temperature preparation of solid–solid phase change polymer (SSPCP) is realized. • One-step embedding technology of SSPCP into the battery module can be realized. • SSPCP shows excellent anti-leakage and heat-tolerance property at high temperature. • SSPCP presents outstanding temperature-control performance for battery modules. The high initiating temperature of polymerization up to 80–100 °C during the preparation of solid–solid phase change polymer (SSPCP) leads to the limitation of the embedding procedure during the construction of the battery modules. Herein, we develop a low-temperature preparation strategy for SSPCPs by introducing a redox initiation system to reduce the decomposition activation energy, thus realizing the procedure for embedding the SSPCP into a battery module. In addition to the intrinsic ~100% anti-leakage performance and ultrahigh heat tolerance up to 250 °C, the SSPCP/expanded graphite composite demonstrates a suitable phase change temperature of 47.8 °C, high thermal conductivity of 2.33 W m−1 K−1, and latent heat of 99.6 J g−1 for battery thermal management, thus delivering a lower maximum temperature (47.4 °C vs. 45.2 °C) for the battery module than traditional composite phase change material during 15 charge–discharge cycles. No leakage traces are detected in the SSPCP module. [ABSTRACT FROM AUTHOR]

l The critical thermal issues of lithium-ion batteries are introduced. l The design principles for batteries thermal management are presented. l The latest advances on battery thermal management systems are summarized. l Emerging technologies for next-generation power batteries are discussed. Replacing conventional gasoline-powered cars with electric vehicles (EVs) can reduce not only pollution emissions but also the dependence on fossil fuels. As the most widely used power source to propel EVs, lithium-ion batteries are highly sensitive to the operating temperatures, rendering battery thermal management indispensable to ensure their high performance, long cycle life and safe operation. In this review, we summarize the recent advances in thermal management for lithium-ion batteries. The critical thermal issues caused by high temperature, low temperature and temperature non-uniformity are firstly discussed. The design principles and the existing thermal management systems are then presented and elaborated extensively. Emerging technologies such as thermoelectric devices and internal heating methods for future battery thermal management are analyzed. We highlight that the combination of passive and active cooling/heating methods is promising to meet the stringent thermal requirements, particularly under dynamic conditions with drastic power fluctuations. Finally, the remaining challenges and perspectives of thermal management systems with high efficiency and durability are provided. This review offers comprehensive guidance on the design of advanced thermal management system for next-generation power batteries. [ABSTRACT FROM AUTHOR]

Battery Thermal Management System (BTMS) plays a significant role in determining the Electric vehicles (EVs) operating range and battery operating life cycle. Indeed, Phase Change Material (PCM) with outstanding characteristics like passive energy utilization to cool the battery, low cost, and effective operation seems to be an attractive option to be used for BTMS of EVs. However, opting for an exact PCM for the required application of the battery system depends completely on the thermal properties of PCM. Therefore, drawbacks and the advancement of PCM integrated BTMS compared to others should be scrutinized to have a comprehensive assessment on the PCM-integrated BTMS. The present review article majorly focuses on: i) - Advanced thermal properties of organic, inorganic, and eutectic PCM for integration with BTMS; ii) - Secondary assisted PCM cooling system for BTMS; iii) - Experimental development carried out with incorporation of composite PCM with BTMS; iv) - Economic comparative analysis on integrating PCM with EVs; v) - Critical analysis on environmental benefits of PCM based BTMS for EVs. In addition, the key outcomes of utilizing nanoparticle dispersed PCM into battery systems are highlighted. A separate section has been elaborated on the techniques used to overcome the drawbacks of thermal conductivity in PCMs. Finally, critical analysis and consolidation of experimentally hybridized and analyzed composite PCM for performance enhancement of batteries presented in the article would be a hot spot for future research work on EVs. [Display omitted] • Effects of PCM on battery thermal performance of EV are analyzed. • Nanoparticle dispersed PCM into battery systems are highlighted. • Nano-particles and metal fins structure is a viable option. • Economic and environmental benefits of PCM based EV are analyzed. [ABSTRACT FROM AUTHOR]

• A hybrid thermal management system with PCM, HP and liquid cooling is proposed. • A surrogate model is established based on Adaptive-Kriging-HDMR method. • Four sensitive factors are determined through global sensitivity analysis. • The optimized system is evaluated in the condition of cycling and thermal runaway. The hybrid thermal management scheme for lithium-ion battery combining the advantages of various thermal management strategies has been widely adopted. However, due to the complex influence parameters involved in the hybrid thermal management system, its optimal design has become a difficult problem. In this study, a hybrid thermal management system based on phase change material (PCM), liquid cooling, and heat pipe is first designed, and then a precise and reliable numerical heat transfer model is established. In order to optimize the system and improve the optimization efficiency, the Adaptive-Kriging-High dimensional model representation (HDMR) method is used to construct a surrogate model of the thermal management system, and the influencing factors sensitivity analysis and optimization design of the hybrid thermal management system are also conducted. The results show that the thermal conductivity of PCM, the thickness of PCM, the length of heat pipe and the velocity of inlet water have a significant influence on the maximum temperature and temperature difference of the battery system. According to the optimization design of these four factors based on the multi-objective particle swarm optimization (MOPSO), it is found that the optimized thermal management system has the best ability to dissipate heat and maintain temperature uniformity as compared to the original design. In addition, this optimization system has the ability to prevent thermal runaway propagation under the condition of thermal abuse conditions. With these prominent performances, the proposed method is expected to provide insights into the engineering design and optimization of the battery thermal management system for electric vehicle. [ABSTRACT FROM AUTHOR]

• A novel liquid cooling plate embedded with PCM for battery thermal management. • The cooling plate provides a modular solution for battery cooling with PCM. • The cooling plate is 36% lighter than an aluminum cooling plate of the same size. • Up to 30% reduction in pump energy consumption is achieved by the new cooling plate. • The cooling plate provides a heating solution for batteries in cold temperatures. In this paper, an innovative liquid cooling plate (LCP) embedded with phase change material (PCM) is designed for electric vehicle (EV) battery thermal management. The proposed cooling plate is named "hybrid cooling plate" as it takes advantage of both active (liquid) and passive (PCM) cooling methods. The hybrid LCP is 36% lighter than a volumetrically equivalent traditional aluminum LCP, and in addition to the cooling capability, it provides a heating solution to slow the temperature loss of the batteries during the cold stop. The thermal behavior of the hybrid LCP for two different scenarios including the cooling performance under a real driving cycle, and the cold stop temperature performance are investigated and compared with a traditional aluminum LCP using a computational fluid dynamics (CFD) model. An experimental test bench is developed to test a prototype of the hybrid LCP and verify the CFD model. The cooling performance results indicate that the use of hybrid LCP could reduce the energy consumption of the pump required for circulating the coolant up to 30% in comparison with an aluminum LCP. Moreover, the novel designed LCP improves the temperature uniformity effectively. It was also found that the hybrid LCP could significantly delay the temperature drop at the cold stop situation of the EV and therefore, reduce the energy needed for the active heating of the batteries after short-term parking. These imply that the hybrid liquid cooling plate concept could be a promising thermal management solution for EVs. [ABSTRACT FROM AUTHOR]

The temperature control technology based on phase change material (PCM) demonstrates excellent performance in the field of battery thermal management. However, the compact and bulky structure of the traditional composite PCM (CPCM) module reduces the energy density of the battery pack greatly, and is unfavorable to the secondary heat dissipation. In this work, we develop a novel PCM cooling structure by substituting the common block-shaped CPCM (B-CPCM) module with serpentine CPCM (S-CPCM) plates. The S-CPCM plates with high shape stability provide a much larger surface area and many air flow channels in comparison to the B-CPCM module, thus endowing the module with outstanding secondary heat dissipation capability. For example, under the same fan power of forced air convection (5.2 W), the S-CPCM module delivers a much lower maximum temperature than the B-CPCM module (51.9 vs. 54.2 °C) during the repeated charge-discharge process. As highlighted here, on the basis of guaranteeing the cooling performance, the S-CPCM cooling structure also saves ~70% of the CPCM amount, and thereby the energy density of the battery module is increased by 13.8 Wh kg−1. Image 1 • Novel serpentine composite phase change material (S-CPCM) plates are designed. • The S-CPCM cooling structure saves 70% of the CPCM amount in the battery module. • The energy density of the module with S-CPCM cooling is increased by 13.8 Wh kg−1 • S-CPCM plates provide air flow channels and large surface area for heat dissipation. • The S-CPCM cooling structure shows much enhanced heat dissipation performance. [ABSTRACT FROM AUTHOR]

• Branch-structured fins are designed for high temperature environment. • Thermal behaviors of modules under different ambient temperatures are compared. • How PCT influences the performance of PCM is investigated under high temperature. Battery modules with phase change material (PCM) cooling inevitably suffer from heat-storage saturation and poor secondary-heat dissipation, especially in high-temperature environments or hot regions. To optimize thermal management, this study firstly explores the thermal behaviors of PCMs with different phase change temperatures (PCTs) in a high-temperature environment. The experimental results show that a PCM with a PCT of 46 °C offers the best cooling effect at a high ambient temperature of 40 °C in this study. For example, the maximum temperature of a cell without PCM reaches 53.3 °C, whereas that of the cell with PCMs having PCTs 40, 46, and 55 °C, are 59.2, 51.6, and 57.5 °C, respectively, during the dynamic cycling process. Nevertheless, the application of above PCM is still unsatisfying because the maximum temperature of the battery in the PCM module exhibits obvious increasing trend with cycles in 40 °C environment. On this basis, several novel fins with multiple heat-flow channels (of V, Y and X shapes) are designed and introduced into the PCM module to enhance the secondary heat dissipation capability. These fins with innovative branch structures deliver excellent performance in alleviating the battery temperature than the traditional rectangular fins, which can be attributed to the ability of the branch structures to increase the heat transfer area by adding heat transfer channels. The results of this work show that the X-shape delivers the best performance in a high-temperature environment of 40 °C by maintaining the maximum temperature of the cell below 47 °C. [ABSTRACT FROM AUTHOR]