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

Due to the high energy density and low production cost, silicon oxide (SiO_x) 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 SiO_x 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 SiO_x anodes, boosting the large-scale commercial applications of the pre-lithiation strategy. First, the hollow porous SiO_x@C spheres (Hp-SiO_x@C) with adjustable shell thickness are designed using a self-transformation method, and then an air-stable pre-lithiated Hp-SiO_x@C (ASP-Hp-SiO_x@C) anode is prepared through an electrochemical pre-lithiation followed by a thermal passivation strategy. The ASP-Hp-SiO_x@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.