Optimization Design and Numerical Study of Liquid-Cooling Structure for Cylindrical Lithium-Ion Battery Pack

Abstract

Thermal management is of great significance to ensure that a battery pack works at a reasonable temperature and avoids thermal runaway. In this study, three different designs of liquid cooling-based lithium-ion battery modules with wavy tubes are proposed. A three-dimensional transient simulation of the designed structure is carried out. The effects of the coolant mass flow rate, separated dual tube structure, connection mode of adjacent tube lines (series mode and parallel mode), and coolant flow direction are discussed. The results show that increasing the mass flow rate of coolant in the range of 0–0.01 kg·s−1 can significantly reduce the maximum temperature of the battery module. On the contrary, the temperature difference increases markedly with the rise of the mass flow rate. Until the mass flow rate is greater than 0.006 kg·s−1, the temperature difference of the battery module changes less and stabilizes at 4.2°C–4.4°C. In addition, compared with the series mode, the parallel mode can improve the thermal performance of the battery module, especially in reducing the maximum temperature. The reverse flow of coolant on both sides of the battery with a separated dual tube structure can obtain the optimal cooling effect. This study provides a new way to optimize the cooling capacity of the thermal management system for a cylindrical lithium-ion battery module.