SYSTEM AND METHOD FOR DETERMINING DEGRADATION OF RECHARGEABLE LITHIUM ION BATTERY

摘要

An MPU performs a degradation diagnosis based on an open circuit voltage characteristic of a rechargeable lithium ion battery indicating how the battery varies in open circuit voltage as the battery varies in capacity to obtain a capacity ratio of a positive electrode, a capacity ratio of a negative electrode, and a deviated capacity of the battery. The MPU applies the capacity ratio of the positive electrode and the capacity ratio of the negative electrode to a predetermined map for degradation attributed to wear to estimate a deviated capacity resulting from degradation attributed to wear and separates the deviated capacity into the deviated capacity resulting from degradation attributed to wear and a deviated capacity resulting from deposition of lithium. The MPU uses at least the deviated capacity resulting from deposition of lithium to determine whether a rechargeable lithium ion battery subject to determination of degradation is reusable and/or recyclable.