Thermal behaviour assessment and electrical characterisation of a cylindrical Lithium-ion battery using infrared thermography

This paper presents an experimental evaluation of the thermal and electrical performance of a commercial 26650 cylindrical LiFePO4 battery cell. The thermal management of lithium-ion batteries is a key problem for electric mobility applications, where batteries are subjected to severe operating conditions. Accordingly, this study aims to demonstrate the reliability of infrared thermography in the quantitative analysis of heat generation in battery cells. In our opinion, infrared thermography can be very attractive owing to: (i) the non-contact nature of this technique and (ii) its capability to quickly scan measurement areas. Consequently, infrared thermography and thermocouple probe results were compared, providing evidence of similar behaviour. Moreover, we present an electrical characterisation of our lithium-ion battery. In particular, the cell potential, open circuit potential, and entropic heat coefficient vis-a-vis the state of charge were experimentally measured. The obtained experimental data were used to evaluate a simplified heat generation term that is widely employed in numerical approaches. The different contributions to heat generation were carefully analysed. The results show that the reversible term considerably influences the total thermal power. Moreover, infrared-based heat generation estimation can be considered reliable.