Analysis of Battery Capacity Decay and Capacity Prediction

Accurate estimation and evolution prediction of the electrical properties of lithium-ion batteries are of great significance for the improvement of battery reliability and optimization of control strategies. Based on the mechanism model of lithium-ion battery, a quantitative and qualitative analysis method is proposed for the state evolution of the composite electrode by analyzing the evolution of the internal state during the battery decay process based on the mechanism model analysis method. Aiming at the working characteristics of the composite electrode, a mechanism model containing multiple material electrodes is established on the basis of a quasi-two-dimensional electrochemical model, and a steady-state model of the composite electrode is established by neglecting the polarization process inside the cell. The study on the decay of composite electrodes under shelf and cyclic aging, through the analysis of the mechanism model, found that the composite electrodes in the decay process of a variety of materials interact with each other, and in the different stages of the decay of different characteristics. Meanwhile, based on the mechanism model analysis method, combined with the decay mechanism of the battery, the capacity performance prediction of the battery is studied, and the analytical method for the capacity decay of lithium-ion batteries in the storage process is proposed.