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

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 effectiveness of different cell cooling strategies on reducing the in-cell temperature gradient within cylindrical cells is analysed through the development of a 2-D transient bulk layer thermal model displaying anisotropic thermal conductivity. The model is validated against experimental temperature measurements in which the peak error of the simulation was found to be 2% and 5% for the experimental test drive cycle and constant 1C discharge respectively. Results indicate that radial cooling with air or singular tab cooling with liquid may be inadequate in limiting cell temperature gradients to below 5 ℃ for HEV type 32113 cells when subject to 4 loops of the US06 drive cycle.