Diagnostics of Lithium-Ion Batteries by Electrochemical Impedance Methods

Possibilities of electrochemical impedance spectroscopy for analysis of self-discharge reasons of prismatic lithium-ion batteries (LIB) are considered. It is shown that conclusions about the causes of self-discharge can be drawn from the topology and parameters of the substitution circuits. Presence of additional series links in the circuit and small value of ohmic resistance between the electrodes allows predicting self-discharge by internal bridges which are represented by electrode materials particles flaking off the electrodes and embedding into the separation. The presence of parallel links in the substitution circuit of one or both electrodes, is an indication of their heterogeneous operation due to the small amount of electrolyte or its decomposition.