Electrochemical impedance spectroscopy analysis for lithium carbon fluorides primary battery

Abstract

The impedance response of Li/CFx pouch cells are measured within a frequency range of 0.1 Hz-100 kHz using a three-electrode cell, which allows to separate the processes of cathode and anode. The measured impedance is interpreted with an equivalent circuit. The impedances are measured at various state of charge (SoC) and after storage at different temperature, indicating that lithium anode dominates the impedance of the whole pouch cell. The frequency value of the onset between the semicircle and the sloped line is an effective parameter to distinguish the electrochemical behavior of Li/CFx pouch cell, especially the power characteristic. These results show that electrochemical impedance spectroscopy is a potential nondestructive method to investigate primary batteries, and suggest that the stability lithium anode is important during storage.