Electrochemical Impedance Spectroscopy Analysis of Lithium Ion Battery Based on Equivalent Circuit Model

Lithium-ion battery has become a promising energy storage device because of its long life cycle, good stability, high energy density and voltage platform. Electrochemical impedance spectroscopy (EIS) is an electrochemical measurement method with small amplitude sine wave potential as disturbance signal. It is a frequency domain measurement method, which studies the electrode system with the impedance spectrum with a wide frequency range, so it can get more dynamic information and structure information of electrode interface than other conventional methods. Consistency of lithium-ion battery packs is a problem that runs through the whole life cycle of battery packs. With the continuous popularization of electric vehicles, the balanced maintenance of lithium-ion battery packs during after-sales and secondary gradient utilization is particularly important. In this paper, the basic principle of electrochemical impedance spectroscopy (EIS), the interface reaction mechanism between electrolyte and electrode materials, and its application in condition monitoring, anode materials and cathode materials research of lithium ion batteries are described, so as to improve the performance and prolong the life of batteries.