Heat Generation Behavior of LFP and NCM Batteries during Long-Term Storage: A Comparative Study

The life and safety of a battery are closely linked to temperature. Designing an effective thermal management system relies on a thorough understanding and analysis of the thermal properties and mechanisms of the battery. Over time, as batteries are used, their thermal characteristics change due to variations in internal SEI thickness, the deterioration of the active material structure, gas production, and electrolyte consumption, all of which are associated with the aging process. In this paper, experiments on both NCM and LFP batteries were made to measure the heat generation characteristics by adiabatic calorimeter. The results showed that the impact of calendar aging on battery heat generation exhibited completely different patterns for the lithium-ion batteries of the two material systems mentioned above. This paper provides guidance for the optimization of heat generation characteristics of battery and the calibration of heat source in the design of battery thermal management system for electric aircraft.