A study into different cell-level cooling strategies for cylindrical lithium-ion cells in automotive applications

Abstract

Previous research has identified that the ageing rate and performance of lithium-ion cells is negatively influenced by unfavourable cell thermal conditions, specifically, high ambient temperatures and large in-cell temperature gradients. In this paper, the thermal performance of tab cooling cylindrical cells, which is not well understood within the literature, is compared to more common radial cooling strategies. The analysis is conducted through the development of a 2D transient bulk layer thermal model displaying anisotropic thermal conductivity. The model is validated against experimental temperature measurements, where the peak error of the simulation was found to be 2% and 5% for the experimental test drive cycle and constant 1 C discharge respectively. Results indicate that radial cooling with air or singular tab cooling with liquid is inadequate in limiting in-cell temperature gradients to below 5°C for HEV type 32113 cells when subject to four loops of the US06 drive cycle.