Formation of physically durable and performance sensitive solid-electrolyte interphase of SiO<i>_x</i> anode for lithium-ion battery

Although SiOx is a well-known promising anode material for Li-ion batteries because of its high energy density and cyclic stability, the inferior electron transport kinetics and morphologically unstable solid-electrolyte interphase (SEI) layer formed on the SiOx anode result in inadequate electrochemical performance. Herein, to overcome the poor electron transport kinetics, a carbon-incorporated/carbon-coated SiOx((C-SiOx)@C) composite is fabricated. In addition, the (C-SiOx)@C electrode is pre-lithiated using a charging circuit under an optimized resistance to form a structurally durable SEI layer with high Li+ diffusivity during the charge–discharge processes. Thus, the (C-SiOx)@C composite exhibits highly improved cycle performance. Elaborately designed SEI composed of LiF for physical sturdiness and Li2O to achieve high Li+ diffusivity resulted in highly improved cyclic performance as well as initial coulombic efficiency.