Graphene‐Encapsulated Nanosheet‐Assembled Zinc–Nickel–Cobalt Oxide Microspheres for Enhanced Lithium Storage

Abstract

Abstract The appropriate combination of hierarchical transition‐metal oxide (TMO) micro‐/nanostructures constructed from porous nanobuilding blocks with graphene sheets (GNS) in a core/shell geometry is highly desirable for high‐performance lithium‐ion batteries (LIBs). A facile and scalable process for the fabrication of 3D hierarchical porous zinc–nickel–cobalt oxide (ZNCO) microspheres constructed from porous ultrathin nanosheets encapsulated by GNS to form a core/shell geometry is reported for improved electrochemical performance of the TMOs as an anode in LIBs. By virtue of their intriguing structural features, the produced ZNCO/GNS core/shell hybrids exhibit an outstanding reversible capacity of 1015 mA h g −1 at 0.1 C after 50 cycles. Even at a high rate of 1 C, a stable capacity as high as 420 mA h g −1 could be maintained after 900 cycles, which suggested their great potential as efficient electrodes for high‐performance LIBs.