A novel and fast method of characterizing the self-discharge behavior of lithium-ion cells using a pulse-measurement technique

Abstract

This publication presents a novel method for characterizing the self-discharge behavior of lithium-ion cells, a pulse-measurement technique. This not only yields the self-discharge in terms of capacity loss, but also uses changes in the open circuit voltage to determine an equivalent self-discharge resistance, Rself. This method is very useful; the required measurement time for characterizing self-discharge behavior is shortened by a factor of 60 (compared to a calendar test of 30 days). This measurement time improvement is also beneficial for investigating the temperature dependence of self-discharge in a lithium ion cell, enabling a quantitative evaluation. Best of all, the pulse-measurement technique can be easily implemented using commercially available measurement equipment. Nonetheless, storage experiments are still indispensable when separating reversible and irreversible capacity loss.