Insights into the Effect of SiO Particle Size on the Electrochemical Performance between Half and Full Cells for Li-Ion Batteries

Silicon monoxide (SiO) has attracted growing attention as one of the most promising anodes for high-energy-density lithium-ion batteries (LIBs), benefiting from relatively low volume expansion and superior cycling performance compared to bare silicon (Si). However, the size of the SiO particle for commercial application remains uncertain. Besides, the materials and concepts developed on the laboratory level in half cells are quite different from what is necessary for practical operation in full cells. Herein, we investigate the electrochemical performance of SiO with different particle sizes between half cells and full cells. The SiO with larger particle size exhibits worse electrochemical performance in the half cell, whereas it demonstrates excellent cycling stability with a high capacity retention of 91.3% after 400 cycles in the full cell. The reasons for the differences in their electrochemical performance between half cells and full cells are further explored in detail. The SiO with larger particle size possessing superior electrochemical performance in full cells benefits from consuming less electrolyte and not being easier to aggregate. It indicates that the SiO with larger particle size is recommended for commercial application and part of the information provided from half cells may not be advocated to predict the cycling performances of the anode materials. The analysis based on the electrochemical performance of the SiO between half cells and full cells gives fundamental insight into further Si-based anode research.