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.