Performance analysis of a novel concave-convex surface liquid cooling plate for a prismatic Li-ion battery pack under high discharge rate

In response to the critical need for efficient heat dissipation in high discharge rate Li-ion batteries, this study introduced a novel Concave-Convex Surface Liquid Cooling Plate (CCS LCP). The CCS LCP was specifically designed to address the rapid temperature elevation and non-uniform thermal distribution observed in prismatic Li-ion battery packs during large discharge rate of 5C. This paper used the computational fluid dynamics simulation as the research tool and proposed a new comprehensive evaluation index (epsilon) to assess the performance of different LCPs in terms of both cooling performance and flow resistance. Firstly, the performance of this novel CCS LCP was compared with that of three traditional LCPs: a water jacket LCP, a Z-shaped linear parallel channel LCP and an LCP with cylindrical splitters. Then, the effects on the CCS LCP by changing the arrangement of inlet and outlet were investigated. Furthermore, the influences on CCS LCP by adding baffles were studied. The results show that the addition of longitudinal or horizontal baffles can effectively decrease applicable inlet mass flow rate to 0.01 kg.s(-1). Self-heat exchange within coolant formed by the addition of horizontal baffles can significantly decrease the maximum temperature of the battery pack (T-max) to 301.64 K and the maximum temperature difference of the battery pack (Delta T-max) to 2.96 K. After comprehensive analyses, the optimal structure is the I-type inlet/outlet arrangement CCS LCP. Comparing I-CCS LCP with other traditional LCPs under the same inlet mass flow rate, I-CCS LCP can reduce Delta T-max by a maximum of 74.97 % and increase comprehensive evaluation index epsilon by 191.12 %. This novel CCS LCP shows an enormous potential in both flow and heat transfer performance and this study offers valuable insights for engineering applications aiming to improve battery reliability in demanding operating conditions.