Detection of lithium plating in large-capacity LiFePO4 batteries based on expansion force characteristics

The lithium plating-stripping reaction occurs in lithium-ion batteries during charging at low temperature, causing changes in expansion force or thickness, which affects battery performance and safety. In this paper, the expansion properties were investigated during charging of a commercial lithium-ion battery at -5°C, and the degree of lithium plating of the battery is effectively associated with the expansion force characteristics through differential voltage and differential expansion force curve analysis method, which further finds that the degree of lithium plating of the battery is correlated with the change of expansion force, and puts forward lithium-ion battery lithium plating detection method based on the differential characteristics of the expansion force. Numerical results show that the amount of lithium plating and expansion force differential characteristics values are gradually increased with the increase of the charging rates, the results obtained in this paper will provide ideasfor the inhibition of lithium plating.