Description:
Despite its extremely high capacity (4200 mA h g -1 ), the practical application of the silicon anode is still frustrated by its poor cycling performance, resulting from severe volume changes and pulverization of electrode material. Introducing graphene in silicon is an ideal approach to address the issues. Nevertheless, the huge size difference between Si and graphene makes the high-quality contact difficult to realize, which seriously harms the electrochemical performance of Si/graphene composite. Herein, a unique Sigraphene layer structure (p-Si@GN) with improved contact interface is fabricated by a facile high-pressure method, in which the surface of silicon particles is fully covered by the graphene layer, restraining the volume changes from multi-angles. The superior structure of layered p-Si@GN composite exhibits multiple desired features for high performance Si-based anodes, such as high Li + storage capacity resulting from high-capacity Si nanoparticles, outstanding electron conductivity ascribing to the formation of continuous graphene conductive network and excellent structural stability owing to the enhanced protective function of graphene layers with improved contacting interface. Tanks to these advantages, the p-Si@GN 40 anode, prepared under 40 MPa pressure, exhibits significantly improved capacity of 2376.0 mA h g -1 at a current density of 0.3 A g -1 , enhanced rate capability of 706.4 mA h g -1 at 3 A g -1 , and superior cycling performance with minor capacity loss after 150 cycles