Failure Modes of Silicon Powder Negative Electrode in Lithium Secondary Batteries

Abstract

Si composite negative electrodes for lithium secondary batteries degrade in the dealloying period with an abrupt increase in
\ninternal resistance that is caused by a breakdown of conductive network made between Si and carbon particles. This results from
\na volume contraction of Si particles after expansion in the previous alloying process. Due to the large internal resistance, the
\ndealloying reaction is not completed while Si remains as a lithiated state. The anodic performance is greatly improved either by
\napplying a pressure on the cells or loading a larger amount of conductive carbon in the composite electrodes.