Three-dimensional CoS2/RGO hierarchical architecture as superior-capability anode for lithium ion batteries

Abstract

For the first time, a three-dimensional hierarchical architecture of CoS₂/reduced graphene oxide (3DCG) with CoS₂ particles uniformly anchored on the graphene network has been synthesized by a facile hydrothermal method. The 3DCG anode exhibits superior electrochemical performances: it delivers a high reversible specific capacity of 1499 mA h g⁻¹ and remains 1245 mA h g⁻¹ after 150 cycles at a current density of 100 mA g⁻¹, which is the highest ever reported for CoS₂-based materials; the rate capability remains 306 mA h g⁻¹ even at 4000 mA g⁻¹. The excellent performance can be attributed to the unique 3D porous structure, in which the reduced graphene oxide (RGO) network can guarantee the high conductivity of the composite, accommodate the volume change of CoS₂ particles during cycling, and shorten the diffusion lengths for lithium ions. The 3DCG composite can be a promising anode candidate for high-performance lithium-ion batteries.