LAUSR

Abstract As an important supplementary part of experiment, multi-scale modeling and simulation plays an important role in reasonable design and performance prediction of lithium-ion batteries. Due to the complexity of spherical diffusion equation, the calculation error of Li-ion diffusion process in solid spherical active particles is an important factor restricting the accuracy of the simplified mechanism model of Li-ion batteries. In this study, based on the quasi-steady state of spherical active particles in Li-ion diffusion processes, the concepts of zero-state response, zero-input response, and total response in the discipline of circuit analysis are introduced to expand the spherical diffusion equation, the analytical solution of Li-ion diffusion process in active particles is solved by using the variable-separation method, and an error-controllable method for solving the approximate solution of diffusion process in spherical particles is proposed and verified. Besides, the computational complexity of the algorithm is very low, therefore, this study is of great significant to construct the high-precision simplified mechanism model of Li-ion batteries and to realize the high-accuracy battery management algorithm on microprocessor systems.