Model for a bipolar Li-ion battery module: Automated model generation, validation and verification

A lithium-ion battery module can comprise a large number of cells, which contain further functional layers and groups. Detailed, mechanistic mathematical modeling of the physicochemical phenomena that occur at different length scales throughout a battery module is therefore a challenging problem. In this paper, we present a method to reduce the computational cost when solving a Li-ion battery model comprising transient equations of change – species, charge, and energy – through model reformulation and a procedure to automate the task of drawing the battery module and solving it numerically. Reformulation is carried out for the model validated with experimental results. The automation not only reduces the overall time to find a numerical solution, but it also removes the chance of human errors during the pre-processing step. The procedure is verified with significant gains in computational cost: the reformulated model is around 40% faster than without the reformulation, and the model for a 50-cell battery module takes only around 14 s to set up numerically. The reformulated mathematical model in combination with automated model generation thus opens up avenues for wide-ranging parameter studies, automated multi-objective optimization of design, layout, management strategies and operating conditions of a battery module.