SOH Estimation and Prediction for NMC Cells Based on Degradation Mechanism Detection

Accurate on board State of Health (SOH) estimation is a key Battery Management System (BMS) function to provide optimal management of the battery system under control. In this regard, this paper presents an extensive study of the degradation mechanism of NMC/Graphite cells based on the study of both incremental capacity (IC) and differential voltage (DV) curves. Moreover, based on the obtained IC curves, a linear relationship was identified between capacity and IC peak intensity for both calendar and cycling ageing. This novel characteristic allows to estimate and even to predict the SOH of NMC/graphite cells.