Abstract

In this study, two inorganic phase change materials (PCM) were tested to be used for thermal control of lithium-ion batteries. Paraffin wax was used as a reference material. To increase thermal conductivity, the PCMs were impregnated into the expanded graphite matrix, forming composite PCM (CPCM). Four types of Li-ion battery packs were manufactured to show the difference in performance between the packs with various CPCMs and No-CPCM. Electrical cycling studies at ambient temperature showed that at C/2 discharge the No-CPCM pack surpasses 35 °C, while all CPCM packs remain around 30 °C, demonstrating similar behavior. At 1C discharge, No-CPCM pack reaches 49 °C, whereas the CPCM packs do not exceed 40 °C. At 2C discharge, the No-CPCM pack overpassed the safety limit of 65 °C and was stopped before completing the first discharge. The CPCM packs successfully completed the cycling. Studies performed at 45 °C demonstrate a similar trend, but with higher peak temperatures. Nail penetration testing proved that the inorganic CPCMс inhibited the pack from self-accelerated degradation, successfully prevented thermal runaway propagation and potential explosion. Low cost and incombustibility make inorganic PCMs а viable alternative to the organic PCMs, with a positive impact on environmental and economic issues.