BATTERY SYSTEM AND DETERIORATION DETERMINING METHOD

摘要

A battery system includes a secondary battery and a controller. A battery voltage of the secondary battery is more susceptible to a positive electrode potential than to a negative electrode potential. The controller acquires a relationship between a resistance change rate and a current value in the secondary battery in a less charged state and determines the deterioration state of the secondary battery based on the acquired relationship. The controller determines the deterioration state of the secondary battery by using a first correlation and a second correlation. In the first correlation, the resistance change rate is reduced as the current value is increased when only deterioration due to wear of the secondary battery (wear deterioration) occurs. In the second correlation, the resistance change rate is increased as the current value is increased when only deterioration due to a salt concentration distribution within the secondary battery (high rate deterioration) occurs.

主权项

1. A battery system comprising:
a secondary battery having a battery voltage more susceptible to a positive electrode potential than to a negative electrode potential; and a controller acquiring a relationship between a resistance change rate and a current value in the secondary battery in a less charged state and determining a deterioration state of the secondary battery based on the acquired relationship, wherein the controller determines the deterioration state of the secondary battery by using a first correlation in which the resistance change rate is reduced as the current value is increased when only deterioration due to wear of the secondary battery occurs and a second correlation in which the resistance change rate is increased as the current value is increased when only deterioration due to a salt concentration distribution within the secondary battery occurs.