Numerical Investigation of Temperature Mitigation in a Lithium-Ion Battery Pack Using Novel Surface Channels for Parallel and Cross Flow

Abstract

Abstract. Thermo-electrochemical modeling of a lithium-ion battery pack having three prismatic cells connected in series has been carried out to evaluate the heat generation in a battery pack. An equivalent circuit model (ECM) based on a second-order resistive-capacitive Thevenin model is employed to solve the electrochemical reaction inside the battery cell. In such a model, all parameters, including battery voltage, heat generation rate, and temperature, vary with the battery state of charge as discharging continues, rather than being considered constant, thereby enhancing the accuracy of the results. The temperature rise of the battery pack is mitigated using parallel flow and cross flow induced by parallel/counterflow channels and novel Z-type channels, respectively. A significant reduction in the average battery temperature of over 40 K has been attained employing surface channels over the surface of the battery. Z-type with base cooling proves to be the most effective, among various configurations, resulting in a 2–3 K reduction in temperature compared to counterflow, which is the worst-case scenario. The counterflow results in better spatial temperature homogeneity, followed by Z-type with base cooling, compared to other approaches. An insignificant effect of Reynolds number on temperature distribution, about 0.2–0.3 K, has been noticed, while increasing the discharge rate from 1C to 2C results in approximately 2–3 K temperature rise when the cooling channel is in operation.