Influence of a Short-Term Thermal Stress on the Performance and the Characteristics of Lithium Ion Cells

Abstract

A new laboratory cell in two electrode arrangement has been developed for this study in order to perform in-situ short-term thermal stress tests on both electrodes. For this study commercially available LiCoO2 cathodes, graphite anodes and LP30 electrolyte has been used. A 60 seconds thermal stress with different temperatures ranging from 100 to 250 °C has been performed at the anode side after the cell formation and capacity tests. By comparison of the charge-discharge behavior of the cells before and after the thermal stress, capacity losses, increasing overvoltages and self-discharge have been observed as a function of the stress temperature. For detection of changes in the anode properties SEM, TGA and CT characterizations were used, and changes in the morphology and composition of the SEI layer were observed.