Simulation study on heat dissipation of a prismatic power battery considers anisotropic thermal conductivity in air cooling system

Heat accumulation could be occurred due to low thermal conductivity in one direction inside the power battery, which may lead to the decrease charging performance and potential thermal runaway. In this study, the impact of the anisotropic thermal conductivity (k_x, k_y, k_z) on the temperature of the battery was analyzed. The anisotropic thermal conductivity was divided into the flow direction, thickness direction and spanwise conductivity. Then, the variation regularity of surface temperature distribution and heat flux are revealed by changing the anisotropic thermal conductivity. The results show that the increase of k_x improves the heat dissipation efficiency of the upstream battery by 24 %. The higher thermal conductivity allows additional heat to be transferred from upstream to downstream along the direction of flow. The increase of k_x makes the temperature difference only about 3 K, which improves the temperature uniformity of the battery. In addition, the impact of k_x on the battery heat dissipation process is more dominant than k_y and k_z. However, there is an upper limit to the impact of k_y on the battery temperature. When the k_y exceeds 10 times the value of k_x, the maximum temperature and temperature uniformity of the battery are almost unaffected by the change of k_y. Meanwhile, the increase of k_z has the minor effect on the temperature distribution of the battery surface. The anisotropic thermal conductivity is adjusted to reduce heat accumulation in the battery and improve the temperature uniformity. This work is beneficial to the engineering application of battery thermal management technology.