Effect Analysis on Thermal Management of Power Batteries Utilizing a Form-Stable Silicone Grease/Composite Phase Change Material

Abstract

Battery thermal management technology based on a phase change material (PCM) demonstrates outstanding performance. However, the low thermal conductivity and leakage of the PCM limit the application for battery thermal management. This paper proposes a polyethylene glycol/boron nitride/expanded graphite composite phase change material (CPCM). In view of the large contact resistance caused by the uneven surface of the CPCM, silicone grease was applied to the CPCM to prepare a silicone grease/composite phase change material (SCPCM). The SCPCM exhibits high shape stability and low contact thermal resistance in comparison with the CPCM. Furthermore, an active PCM thermal management system was designed to optimize the thermal management performance of the battery module. The experiment results indicated that the SCPCM thermal management showed a good thermal management performance at low discharge rates (1C and 2C), and the maximum temperature and temperature difference in the module were kept within 50 and 5 °C, respectively. However, at a discharge rate of 3C, the heat storage capacity of the SCPCM reaches saturation, and the heat dissipation capacity decreases. In addition, the water cooling coupled with PCM cooling (W-PCM) battery module always showed the best thermal performance. The W-PCM thermal management method can still effectively improve the thermal saturation problem of the PCM thermal management system after 10 charge and discharge cycles at 4C discharge rates.

Thermal-Switchable, Trifunctional Ceramic–Hydrogel Nanocomposites Enable Full-Lifecycle Security in Practical Battery Systems

“…We measured the dynamic scanning calorimetry (DSC) profiles of the nanocomposites with 2.7 g of ceramic nanobelts and 50 g of hydrogels from 25 to 70 °C (Figure 4a). The measured total enthalpy (25−70 °C) can reach 179.6 J g −1 , close to many advanced PCMs (Figure 4b), such as silicone grease (161.02 J g −1 ), 34 paraffin-expanded graphite/copper foam (75.00 J g −1 ), 35 and paraffin (124.90 J g −1 ). 36 Moreover, the corresponding specific heat is higher than that of most reported coolants, including n-eicosane (2.40 J g −1 K −1 ), 37 Ga 68 In 20 Sn 12 (0.35 J g −1 K −1 ), 38 thermal paste (1.70 J g −1 K −1 ), 6 greases (1.20 J g −1 K −1 ), 39 polydicyclopentadiene (1.40 J g −1 K −1 ), 40 and glycol solution (3.40 J g −1 K −1 ).…”

“…The organic-based PCMs used in state-of-the-art battery systems usually have a relatively low specific heat capacity. Moreover, their combustion will introduce a large amount of additional heat. − Thus, our ceramic–hydrogel nanocomposites will realize effective cooling and fire-extinguishing functionalities during TR.…”

Recent Developments of Thermal Management Strategies for Lithium‐Ion Batteries: A State‐of‐The‐Art Review

“…In their results, the EG‐based PCM possessed better cooling efficiency than copper foam–based PCM. Wu et al [ 138 ] also replaced traditional PCM with PEG/BN/EG composite PCM and used silicone grease to decrease the interfacial contact resistance between PCM and battery. After coupling liquid cooling, the T max and Δ T max values of battery pack could be kept below 45 and 3.5 °C even at a discharge rate of 4 C. Recently, aiming to weak thermal propagation inside battery pack, Niu et al [ 139 ] investigated the effect of low‐thermal‐conductive PCM from the perspective of thermal insulation.…”

Investigation of the thermodynamic properties of hydrates as cooling phase change materials for their implementation in electric vehicles

“…Paraffins, fatty acids, alcohols, esters and glycols are known organic PCMs. [7][8][9][10] However, their low thermal conductivity (0.1-0.35 W m À1 K À1 ) and flammability make them less effective and bring safety concerns. 11,12 Metallic PCMs are attractive because of their high thermal conductivity 13 and higher heat capacity than organic PCMs.…”