Joint Grey Correlation Degree based Incremental Capacity Analysis for State-of-Health Estimation of Lithium Ion Battery

In order to prolong the service life, increase the efficiency of operation, and ensure the working safety during the usage of lithium ion batteries (LIBs), it is necessary to develop a reliable and accurate state-of-health (SOH) estimation for LIBs. In this context, a novel method based on joint grey relation analysis is proposed to analyze the unique shape of incremental capacity (IC) curve for LIBs. The proposed method obtains optimal partial IC curve according to inverse accumulated generating operation and slope correlation degree. Experiments are conducted on two lithium cobalt batteries for their whole service life to verify the performance of the proposed method. Results show that the proposed method can accurately estimate the SOH with the maximum estimation error of 2.94%.