Electrothermal Dynamic Modelling for Battery Management in Space Applications

Challenges faced by battery energy storage systems (BESSs) space applications, such as mass limitations, extremely severe temperature conditions, pressure differentials shocks and radiation, and mechanical shocks, makes battery thermal management a crucial aspect. To keep cells in a safe operating window, electrothermal management can exploit internal heat storage systems, directly integrating Phase Change Materials (PCMs) in the battery pack. The present paper investigates the integration of electrochemical and thermal dynamics of the Li-ion battery system, providing a dynamic electrothermal model of the BESS. The thermal dynamics describe the behaviour of the internal heat storage system constituted by incapsulated RT64HC paraffin PCM. It results in an accurate BESS electrothermal dynamic model of a battery pack designed for space applications, that considers real battery dynamics deduced from a suitable experimental campaign, together with all the real components of the battery system contributing to the thermal dynamics. Simulation, performed at 80°C environmental temperature, provides Li-ion cells temperature evolution due to both heat exchange with the environment and heat internal generation due to the battery operation. Moreover, the model allows to assess the impact of PCM integration in terms of mean and peak temperature achieved by Li-ion cells.