Evaluation of Alternative Methods for Determination of Battery Cells Heat Capacity and Thermal Resistance

Summary:

Thermal characterisation of battery cells is counted as an important basis for batteries thermal modelling amongst which Heat Capacity has a crucial role. Bulk Heat Capacity and Thermal Resistance can be determined using expensive experimental equipment such as Calorimeters or deconstruction of battery cells. While recent published works [3] have shown a promising method consisting of solving heat transfer theoretical equations from experimental cycling data, this study aims to evaluate the efficiency and replicability of a relatively cheap, highly accurate method to determine Heat Capacity and Thermal Resistance of battery cells using modular battery testing fixtures. The investigation has been carried out for Melasta pouch Lithium-Polymer cell (LiCoO2). Calorimetry tests have been used initially to determine the thermal characterisation of the cell followed by in house thermal test to verify the proposed method using modular battery testing fixture. The results with low frequency current pulsing showed a good agreement with calorimetry measured cell heat capacity.