Comparison of lumped diffusion models for voltage prediction of a lithium-ion battery cell during dynamic loads

Three different time-dependent lumped battery models are presented, using a limited set of only either three or four fitting parameters. The models all include one linear (resistive), one non-linear (kinetic) and one time-dependent element, the latter describing the diffusive processes in the battery. The voltage predictive capabilities of the models versus experimental dynamic load data for a plug-in hybrid vehicle battery are compared. It is shown that models based on a diffusion equation in an idealized particle perform similarly to a model based on an RC (resistive-capacitor) pair. In addition, by exchanging the RC element by a diffusion equation in an idealized particle it is also shown that it is possible to reduce the number of needed fitting parameters by one.