Ge@CNFs Anchored on 3D Graphene Foam for Binder‐Free and High‐Efficiency Anodes in Li–Ion Batteries

Abstract

AbstractA spider‐like Ge@CNFs/3D graphene nanocomposite is prepared and used as a binder‐free, large‐capacity, high‐rate, and long‐life anode in lithium‐ion batteries (LIBs). The carbon nanofibers (CNFs) are radially grown on the Ge nanoparticles and then attached onto the 3D graphene foam to form Ge@CNFs/3D graphene. The CNFs buffer the internal stress induced by the volume change, alleviate Ge NP detachment or break down, and prevent aggregation of Ge during cycling. Moreover, the integrated structure of the 3D graphene facilitates fast electron transport and rapid diffusion of Li ions. The obtained spider‐like Ge@CNFs/3D graphene composite shows a capacity of 594 mA h g−1 (based on total mass of the electrode) after 1200 cycles at a current density of 0.8 A g−1. Furthermore, at 12.8 A g−1, the Ge@CNFs/3D graphene nanocomposite delivers a reversible capacity of 474 mA h g−1, corresponding to 74% capacity retention at 0.32 A g−1, rendering it promising for application in high‐performance LIBs.