Thermal performance of battery thermal management system using composite matrix coupled with mini‐channel

Abstract

In order to improve cycle life and the working performance of the Li‐ion batteries and the reliability of battery thermal management (BTM) system, a composite matrix coupled with mini‐channel based BTM system is designed in this paper. The thermal performances of the BTM system at different discharge rates under the condition of air natural convection (ANC) and composite matrix (CM) are studied. The results show that the thermal conductivity of the PCMs/EG composites is about 28 times larger than the pure PCMs. Meanwhile, the latent heat is 134.28 J/g after adding EG. The batteries possess larger heat production both at larger state of charge (SOC) and lower SOC. Compared with ANC system, the highest temperature and the Δ T max of the battery modules with CM system at the discharge rates of 3 C are 40.5°C and 2.4°C, respectively. When the battery modules coupled with mini‐channel, the 6 cooling channels with the inlet mass flow rate at 2 × 10 −3 kg/s has the best cooling performance. The highest temperature of the packs could be controlled below 40.1°C and the Δ T max is no more than 1.4°C during the cycle process at the discharge rate of 3 C(I = 30 Ah).