Research on nondestructive measurement of the cross-plane thermal conductivity of a prismatic lithium-ion cell

With the extensive use of lithium-ion cells, cell thermal safety has been widely concerned and investigated. The thermal conductivity of the cell is one of the important thermal parameters of the battery thermal management system. This work provides rapid and nondestructive measurement of the cross-plane thermal conductivity based on the alternating positive and negative pulse (APNP) test, and this method is verified by the heating plate method. The results show that when the duration of APNP pulse is less than 72 s, the error of cross-plane thermal conductivity is almost within +/- 2%, and it indicates that reducing the pulse duration can improve the cross-plane thermal conductivity performance. Additionally, with the cell temperature increasing, the thermal conductivity decreases gradually. This study highlights that the heat dissipation scheme of the cell needs to be adjusted to cope with the deterioration of thermal conductivity as the cell temperature increases.