Calendar ageing model of Li-ion battery combining physics-based and empirical approaches

Abstract

A prognosis model named “Dual-tank ageing model”, combining empirical ageing laws for electrode capacity fading and a physics-based model for the Solid Electrolyte Interphase growth, is developed. The ageing laws for the positive and negative electrodes take into account the operating conditions (i.e. temperature and SOC) while a SEI growth model is implemented to account for the lithium consumption at the negative electrode. The model is identified and validated on commercial 43 Ah Graphite/LMO-NMC Li-ion cells in calendar ageing condition at different temperature and SOC. In calendar ageing conditions, the model is able to forecast the ageing of the cell while capturing the evolution of internal parameters such as electrode capacities, electrode potentials and lithium contents.