Accommodation of Two-Dimensional SiOx in a Point-to-Plane Conductive Network Composed of Graphene and Nitrogen-Doped Carbon for Robust Lithium Storage.

Abstract

Silicon oxides (SiOx) are one of the most promising anode materials for next-generation lithium-ion batteries owing to their abundant reserve and low lost and high reversible capacity. However, the practical application of SiOx is still hindered by their intrinsically low conductivity and huge volume change. In this regard, we design a novel anode material in which sheet-like SiOx nanosheets are encapsulated in a unique point-to-plane conductive network composed of graphene flakes and nitrogen-doped carbon spheres. This unique composite structure demonstrates high specific capacity (867.7 mAh g-1 at 0.1 A g-1), superior rate performance, and stable cycle life. The electrode delivers a superior reversible discharge capacity of 595.8 mAh g-1 after 200 cycles at 1.0 A g-1 and 287.5 mAh g-1 after 500 cycles at 5.0 A g-1. This work may shed light on the rational design of SiOx-based anode materials for next-generation high-performance lithium-ion batteries.