Promoting Effect of Si–OH on the Decomposition of Electrolytes in Lithium-Ion Batteries

The promoting effect of hydroxyls on a silicon surface on the decomposition of an electrolyte is studied by comparing the performance of silicon–hydroxyl (Si–OH) and silicon–alkyl (Si–C3H7) electrodes. X-ray photoelectron spectroscopy (XPS) characterization of solid electrolyte interphase (SEI) layers on both electrodes demonstrates the influencing mechanism that hydroxyls can react with LiPF6 to form POF3, which further induces the decomposition of the electrolyte solution. This study provides a new consideration that limiting the amount of hydroxyls on the silicon surface in an appropriate range is significant to the electrochemical performance of silicon-based anode materials.