Reduced Graphene Oxide-Wrapped Novel CoIn(2)S(4) Spinel Composite Anode Materials for Li-ion Batteries

In this study, we proposed a novel CoIn(2)S(4)/reduced graphene oxide (CoIn(2)S(4)/rGO) composite anode using a hydrothermal method. By introducing electronic-conductive reduced graphene oxide (rGO) to buffer the extreme volume expansion of CoIn(2)S(4), we prevented its polysulfide dissolution during the lithiation/de-lithiation processes. After 100 cycles, the pristine CoIn(2)S(4) electrode demonstrated poor cycle performance of only 120 mAh/g at a current density of 0.1 A/g. However, the composition-optimized CoIn(2)S(4)/rGO composite anode demonstrated a reversible capacity of 580 mAh/g for 100 cycles, which was an improvement of 4.83 times. In addition, the ex situ XRD measurements of the CoIn(2)S(4)/rGO electrode were conducted to determine the reaction mechanism and electrochemical behavior. These results suggest that the as-synthesized CoIn(2)S(4)/rGO composite anode is a promising anode material for lithium ion batteries.