The judgment method of lithium battery performance degradation

The judgment method of lithium battery performance degradation reason of the present invention, is related to the judgement of battery electrical property, and step is: obtaining the charging Δ v-t curve of lithium battery and obtains the electric discharge Δ v-t curve of lithium battery；Calculate the area s value for being included between two charge and discharge Δ v-t curves；The form calculus that voltage difference and time integral are used to area s, obtains the degree coefficient k as cell performance decay i ；By comparing the corresponding charging Δ v-t curve of the different cycle charge-discharge number of lithium battery and electric discharge Δ v-t curve, judge lithium battery performance degradation reason, overcomes the prior art and have the defects that cannot achieve the progress lithium battery performance degradation reason judgement during routine use of lithium battery.