Chemically Integrated Two- Dimensional Hybrid Zinc Manganate/Graphene Nanosheets with Enhanced Lithium Storage Capability

摘要

Hybrid inorganic/graphene two-dimensional (2D) nanostructures can offer vastly open large surface areas for ion transport and storage and enhanced electron transport, representing a promising material platform for next-generation energy storage. Here we report chemically integrated hybrid ZnMn_2O_4/graphene nanosheets synthesized via a facile two-step method for greatly enhanced lithium storage capability. The hybrid 2D nanosheets are composed of ultrafine ZnMn_2O_4 nanocrystals with amean diameter of～4 nmattachedto and well dispersed on the surface of reduced graphene oxide sheets. The hybrid nanosheets based anode offers a high capacity of～800 mAh g~(-1) at a current rate of 500 mA g~(-1), excellent rate capability, and long-term cyclability with reversible capacity of～650 mAh g-1 over 1500 cycles at a current density of 2000 mA g~(-1). Moreover, when tested in a temperature range of ～0-60℃, the designed anode can maintain high discharge capacities from 570 to 820 mAh g~(-1).