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

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, Rsof. 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. (C) 2014 Elsevier B.V. All rights reserved.