Stabilized surface of prelithiated electrode for high energy density batteries

Abstract

Prelithiation has been widely accepted as one of the most promising strategies to compensate for the loss of active substance and to improve the initial Coulombic efficiency in Silicon-based anode for advanced high-energy–density batteries. Nevertheless, the prelithiated anode is highly reactive with air, causing insulating products to be produced and degrading full battery’s performance. Herein, we have developed a strategy using fluoroacetonitrile treatment to eliminate redundant lithium and generate LiF-based inorganic compounds on the surface of the prelithiated electrode. Such method not only reduces the reactiveness of the prelithiated anode, but also enhances the ionic conductivity of the Solid Electrolyte Interface (SEI). This stabilized electrode interface could retain high performance even after being exposed to −50 °C dewpoint for 48 h, or under 20 % humidity. The LiF-rich surface works as an artificial SEI, remarkably improving the capacity, Coulombic Efficiency of Si-based anodes and cyclability in high energy density batteries.