A critical SiOx layer on Si porous structures to construct highly-reversible anode materials for lithium-ion batteries

Abstract

A novel Si/SiO_x porous structure with a SiO_x coating layer of varying thicknesses was prepared via a simple annealing and acid washing process. When used as an anode material for lithium-ion batteries, the Si/SiO_x porous structure with an ∼9 nm SiO_x coating layer demonstrates significantly improved electrochemical performance with a high reversible discharge capacity of over 915 mA h g⁻¹ after 500 long cycles at 1 A g⁻¹. The lithiation mechanism of a SiO_x layer of different thicknesses has also been investigated.