Experiment investigation on a novel composite silica gel plate coupled with liquid-cooling system for square battery thermal management

Abstract

Battery thermal management (BTM) technology has been widely utilized in pure/hybrid electric vehicles. In this study, a novel and effective hybrid cooling system including composite silica gel plate (CSGP) coupled with cooling tubes has been designed for battery module. Combining the excellent cooling effect of copper tubes and CSGP with low contact thermal resistance between each other, the coupling of CSGP and copper tubes is a feasible and effective method with more suitable temperature and smaller temperature difference. For comparison, the natural cooling module and the forced air convection module (CSGP-FC) based CSGP have also been designed. The experiment results revealed that the natural cooling module was hardly to satisfy the requirements of temperature in practical application. Meanwhile, although the CSGP-FC could enhance the heat dissipation at a certain degree, it was still not enough to control the temperature of the module below 45 °C after ten cycling tests. Compared with natural cooling module and CSGP-FC, the CSGP coupled with copper tubes can absorb the heat quickly and transfer it through the water flowing in the copper tubes efficiently, which can control the maximum temperature (Tmax) and make it have a decreasing tendency in ten charge and discharge cycles. The liquid cooling module (CSGP-LC) with 0.8 m/s water flowing rate can control the Tmax below 42.7℃ and temperature difference (ΔT) within 2.7 ℃ at 4C discharge rate. In addition, the energy consumption of the CSGP-LC was half of the CSGP-FC. It should be noted that the expanded graphite (EG) and copper foam added into silica gel (SG) can transfer the heat generating by batteries to copper tubes timely and promptly owing to high thermal conductivity, giving rise to a superior thermal management effect for battery module, especially at high discharge rate. Thus, it can be concluded that this designed cooling approach can provide a new insight for optimizing structure of liquid cooling technology and greatly promote the development of BMS systems.