Internal Redox Couple in Silicon-Graphite Anode and its Influence on Degradation of Anode
Journal
arXiv Materials Science (cond-mat.mtrl-sci)
Date
2019.01.08
Abstract
Recent demands for long range electric vehicles have insisted on high capacity lithium-ion batteries (LiBs) by blending of silicon with graphite. In order to enhance the cell performance, it is important to understand interaction of lithium-ion movements in and between two anode materials with different electrochemical reactions, e.g. formation of Li-Si alloy accompanied with high volume change and intercalation of lithium-ion in graphite during lithiation. Here, we firstly report the methodology for deconvolution of the mixed state in silicon-graphite anode and detailed mechanism on internal redox reaction between silicon and graphite and sequential influence on degradation of silicon-graphite anode. Our results provide an insight to design of materials and an electrode for high performance of a cell.