Experimental and numerical investigation of a hybrid battery thermal management system based on copper foam-paraffin composite phase change material and liquid cooling

Abstract

• A liquid cooling-based BTMS using CPCM was investigated under different Re , current rates and ambient temperatures. • Elevated Re of liquid cooling will increase temperature non-uniformity within the battery pack, while the temperature differences will decrease once Re further improves. • For each battery pack, parametric study needs to be carried out to reach the equilibrium between the T max , Δ T max and pump power. • Liquid cooling controls the maximum battery temperature under high ambient temperature and warms up the battery under low ambient temperature. The battery thermal management system is essential to the electric vehicle. In this paper, a battery pack consisting of 20 cylindrical lithium-ion batteries, along with the copper foam/ paraffin composite phase change material, and liquid cooling channels were set up. A numerical model was built based on the physical model, which was validated by the experimental results. The experimental and numerical test revealed elevated Reynold numbers ( Re ) will increase temperature non-uniformity within the battery pack, while the temperature differences will decrease once Re further improves. Under 0.5C discharge, the maximum temperature difference ( Δ T max ) within difference cells increased from 0.2 to 1.2 K as Re increased from 0 to 28, then it decreased to 0.4 K with Re increased to 112. The study on the current rate effect revealed that a higher current rate could lead to both higher maximum battery temperature and higher Δ T max . Under different ambient temperatures, liquid cooling is necessary as it can help with warming up the battery in a cold environment or reducing the maximum temperature in a hot environment. Compared with pure phase change material (PCM) cooling, at the end of discharge, the hybrid PCM/liquid cooling formed an 8 K temperature increase and a 13K temperature decrease under a low initial temperature of 288 K and a high initial temperature of 318 K, respectively.