A novel algorithm for heat generation and core temperature based on single-temperature in-situ measurement of lithium ion cells

Lithium-ion batteries are a promising technology for efficient energy conversion. Despite the significant advancements made in capacity and lifespan, a suitable battery thermal management system is necessary for more safety and reliability. The heat generation rate and core temperature are critical parameters for the design of the battery thermal management system and the monitoring signals for the battery management system, respectively. In consideration of said critical parameters, in the present paper, a novel algorithm for heat generation and core temperature is proposed based on single-temperature in-situ measurement of lithium-ion batteries. The in-situ measurement is ensured by introducing the calculation of the local equivalent convection heat transfer coefficient, and only obtaining the surface temperature. To verify the proposed method, cylindrical 5 Ah 26,700 lithium-ion batteries were used as test samples. The results of the experiment reveal that the error between the calculated core temperature and the measured core temperature was less than 4% during the entirety of the 2 C and 1.5C discharging processes. The efficacy and accuracy of the core temperature demonstrate that the proposed method could be a reliable tool in practice for battery thermal management and fault monitoring.