Strongly coupled hybrid ZnCo2O4 quantum dots/reduced graphene oxide with high-performance lithium storage capability

Mesoporous binary metal oxides/reduced graphene oxide (rGO) two-dimensional nanostructures can provide open large surface areas for lithium ion access and storage, holding a great promise as high-performance electrode materials for next-generation energy storage. In this work, we develop an effective strategy involving a simple polyol process and a facile thermal annealing treatment, to synthesize ZnCo2O4 Quantum Dots (QDs)/rGO hybrid. Due to the large specific surface area, strongly coupled interaction and synergic effect between ZnCo2O4 QDs and rGO, the hybrid shows excellent lithium storage ability, with high reversible specific capacity, and superior rate performance, as well as ultralong cycle life. After 100 cycles, the ZnCo2O4 QDs/rGO2 delivers a capacity of 1062 mAh g−1 at a current density of 500 mA g−1. Even cycling at 2000 mA g−1 up to 1000 cycles, the reversible capacity still preserves 682.5 mAh g−1. These electrochemical results indicate the ZnCo2O4 QDs/rGO2 hybrid could be a promising candidate material as a high-performance anode material for lithium-ion batteries.