GS0608-254 Electrochemical degradations caused by mechanical damages in Li-ion battery electrodes

Abstract

Silicon is a promising anode material for lithium-ion battery application due to its high specific capacity. However, when silicon is lithiated, it can undergo a volume expansion, which leads to an extensive fracturing. This is thought to be a primary cause of the rapid decay in cell capacity routinely observed.. To solve this problem, a more thorough understanding of how the material degrades is necessary to help cycling techniques that may be capable of reduce capacity fading. In this study, we report in situ acoustic emission and laser microscope observation of volume change in Si negative electrodes. The largest number of emissions occurred on the first lithiation and corresponding to volume change of the silicon negative electrode. this study demonstrates that AE and laser microscope observation is a powerful tool to survey the real-time mechanical damage and electrochemical degradation in the electrode.