https://www.mdu.se/

The electrochemical reactions and heat generation mechanism inside lithium ion batteries (LIBs) are complex, which can be influenced by many factors. Precise mathematical modeling and visualization of LIB internal states are of importance for battery management systems. A model based on coupling electrochemical and thermal characteristic is established, in which the characteristics of battery shape and micro-geometry structure are also considered. Moreover, a method is further proposed to obtain model parameters, which combines measurements and data-driven parameter identification. To visualize lithium ion concentration in solid-phase, numerical equations describing the electrochemical reaction are established based on the lithium ion diffusion mechanism, which can explain the coupling effects of temperatures and charging rates on LIB capacity. model validation results show that the prediction error of terminal voltage is less than 50 mV and the estimation error of temperature is less than 2 ℃.