A novel carbon microspheres@SnO2/reduced graphene composite as anode for lithium-ion batteries with superior cycle stability

Abstract

Many advantages made SnO2 a potential anode for lithium-ion batteries, but huge volume expansion during cycling seriously impeded its practical application. Here, a novel double-carbon structure with low graphene weight proportion was successfully prepared using a facile hydrothermal method to enhance the long-cycle stability of SnO2 as anodes for lithium-ion batteries. In this structure, SnO2 nanoparticles were formed around the surface of the carbon microspheres (CMS), and the reduced graphene (GR) shuttled through the outer layer. As anodes for lithium-ion batteries, the SnO2 protected by dual carbon (CMS@SnO2/GR) exhibited outstanding cycle performance with an initial reversible capacity of 789.5 mAh g-1 and the reversible capacity retention rate of 68.6% after 350 cycles at 200 mA g-1. The abundance free space among CMS, nano-scale, and the excellent flexibility of graphene were all contributed to alleviating the volume variation of CMS@SnO2/GR during the lithiation and delithiation.