Ge–graphene–carbon nanotube composite anode for high performance lithium-ion batteries

Abstract

A Ge–graphene–carbon nanotube composite electrode was constructed by germanium (Ge) nanoparticles anchored on reduced graphene oxide (Ge–RGO) intertwined with carbon nanotubes (CNT). In this unique structure, the graphene sheets improve the electrical conductivity and buffer severe volume changes. Additionally, the CNT mechanically binds together with Ge–RGO to maintain the integrity of the electrodes and stabilize the electric conductive network for the active Ge nanoparticles, leading to better cycling performance. As a result, the designed anode exhibits an outstanding energy capacity up to 863.8 mA h g⁻¹ at a current density of 100 mA g⁻¹ after 100 cycles and good rate performances of 1181.7, 1073.8, 1005.2, 872.0, 767.6, and 644.8 mA h g⁻¹ at current densities of 100, 200, 400, 800, 1600, and 3200 mA g⁻¹, respectively. Our results indicate that the hybrids exhibit considerably improved lithium storage performance.