Construction of air-stable pre-lithiated SiOx anodes for next-generation high-energy-density lithium-ion batteries

Due to the high energy density and low production cost, silicon oxide (SiOx) is recognized as one of the most promising anode materials for lithium-ion batteries. However, the low initial coulombic efficiency and rapid capacity attenuation of SiOx anodes severely restricts its commercial application. Here, we propose a scalable strategy of pre-lithiation followed by a thermal passivation to improve the initial coulombic efficiency of SiOx anodes, boosting the large-scale commercial applications of the pre-lithiation strategy. First, the hollow porous SiOx@C spheres (Hp-SiOx@C) with adjustable shell thickness are designed using a self-transformation method, and then an air-stable pre-lithiated Hp-SiOx@C (ASP-Hp-SiOx@C) anode is prepared through an electrochemical pre-lithiation followed by a thermal passivation strategy. The ASP-Hp-SiOx@C anode delivers high initial coulombic efficiency of 99.2% and stable cycling performance after being exposed to the atmosphere with 10%–20% relative humidity for 48 h.