Controllable preparation of disproportionated SiOX/C sheets with 3D network as high-performance anode materials of lithium ion battery

Abstract

Silicon suboxide (SiOX) is a promising anode material for lithium ion battery (LIB). However, oxygen-dependent SiOX poses a great impact on its cycling stability, which is difficult to controllably prepare. Additionally, the aggregation of nano-scale SiOX restricts the diffusion of lithium ion and structural stability during cycles. Herein, we realize the controllable preparation of porous SiOX/C sheets with various oxygen content and graphite-like carbon as anode materials of LIB. It is found that high oxygen content and a 3-dimensional network in SiOX/C can ensure high structural stability during cycles. As-prepared SiOX facilitates the growth of graphite-like carbon with high defect density, improving their electron and ion conductivity. As-prepared SiOX@C sheets deliver superior reversible capacity, cycling stability and rate performance (the second discharging capacity of 717.4 mAh g−1 at 100 mA g−1 with high initial Coulombic Efficiency of 64.08% is obtained; its capacity retention is as high as 100.44% against the second discharging capacity after 200 cycles; at a high current density of 2000 mA g−1, its reversible capacity still remains 389 mAh g−1). This work provides a novel and simple approach to controllably prepare disproportionated SiOX@C sheets with the 3-dimensional network as ultrastable SiOx-based anode materials of LIB for practical application.