A numerically efficient method of solving the full-order pseudo-2-dimensional (P2D) Li-ion cell model

Abstract An efficient method of solving the full-order pseudo-2-dimensional (P2D) Li-ion cell model is presented. The full-order P2D model consists of a set of tightly coupled differential equations that need to be solved numerically as the analytical solution to the model does not exist. Reducing its computation complexity will broaden its applications including real-time controls, parameter optimizations, and long-term cell life predictions. In this study, a subset of differential equations is solved in a sequential manner to minimize computational cost associated with solving partial differential equations in each time step. Differential equations are solved numerically based on the finite volume method (FVM) and the proposed method is implemented in MATLAB. For benchmarking, the model output and the computation time are compared against those from the same model implemented in COMSOL Multiphysics. The proposed model was able to accurately match the COMSOL full-order P2D model internal dynamics such as Li+ plating potential and Li+ concentration distributions that may be critical when incorporating degradation mechanisms and developing fast charging protocols. As an additional benchmarking, the model output is compared against the output from a couple of reduced-order Li-ion cell models – a single particle model (SPM) and GH-Multi-Scale Multi-Domain (MSMD) model [G.-H. Kim et al. J. Electrochem. Soc., 164 (6) A1076 (2016)].