Analysis of the Aging Mechanism of Lithium-ion Batteries Based on the Incremental Capacity Curve Peak Decomposition Method

Lithium-ion battery, as a complex electrochemical system with strong non-linear and time-varying properties, is difficult and unreliable to estimate its state-of-health (SOH) by only relying on capacity estimation. Thus, it is essential to identify the internal ageing mechanism of batteries utilizing sampling data obtained from the battery management system (BMS) without dismantling the battery. In this paper, the peak area characteristics of the incremental capacity curve are connected to internal electrochemical reactions of batteries based on the Nernst equation, which is used to achieve a quantitative estimation of the battery ageing mechanism. The experimental results validate the effectiveness of the proposed method in quantitively calculating loss of active material occurring in the positive electrode and the loss of lithium inventory.