Fabrication\nof Graphene-Encapsulated Porous Carbon–Metal Oxide Composites\nas Anode Materials for Lithium-Ion Batteries

Abstract

Porous\ncarbons such as CMK-3 are commonly used as matrices to accommodate\nmetal oxides for the improvement of their electrochemical performance.\nHowever, the mesostructure of CMK-3 may be destroyed gradually with\nthe increase of metal oxide content and some particles are inevitably\nformed outside the pores of CMK-3, leading to a gradual decrease in\ncapacity and poor cycling performance. Herein, graphene-encapsulated\nCMK-3-metal oxides (Fe₃O₄ and NiO) are synthesized\nthrough a stepwise heterocoagulation method and exhibit improved electrochemical\nperformances compared to uncoated CMK-3-metal oxides. The core–shell\nstructure of these novel composites can protect the metal oxide particles\non the surface of CMK-3 and avoid the aggregation of porous carbon–metal\noxides. Moreover, the introduction of graphene may stabilize the mesostructure\nof CMK-3 during lithiation and delithiation processes and improve\nthe electronic conductivity of the composite, which are conducive\nto enhancing electrochemical performances of porous carbon-supported\nmetal oxides.