Volume 39: Energy Transitions toward Carbon Neutrality: Part II

Thermal Management of Lithium-ion Batteries at Low Temperature Based on Composite Phase Change Material Wenqing Wang, Bin Liu, Xiaodong Fu, Sitong Huo, Kuining Li

Abstract

The operating performance of lithium-ion batteries will degrade in extremely cold environments. A thermal management system for cold temperatures to make the lithium-ion batteries work in a reasonable temperature range is significant. This paper proposes a low-temperature battery thermal management system based on composite phase change material that preheats batteries quickly under cold environments with heating effect. The chosen CPCM of paraffin (82 wt%), graphite (15 wt%) and electrolytic copper powder (3 wt%) has the leakage rate of 4.43 %, the thermal conductivity of 6.256 W/(m·k), the latent heat of solidification of 152.68 J/g, the latent heat of melting of 164.77 J/g, and at -30 °C the electrical conductivity of 0.357 S/cm. Under the preheating effect of the CPCM, Lithium-ion battery can discharge at -30 °C with a small current. Furthermore, the CPCM rapidly heats up the single battery from -20 °C to 10 °C after the current flows through it, a process that consumed only 258 s (1 C) and 189 s (2 C), and the maximum temperature difference between the various parts of the battery is 4.2 °C and 4.8 °C, respectively. The results of the battery preheating test show that the chosen CPCM has good heating capacity, thermal uniformity and thermal conversion efficiency.

Keywords lithium-ion battery, composite phase change material, self-preheating, thermal conversion efficiency, low-temperature battery thermal management