Fabrication of graphene-encapsulated porous carbon-metal oxide composites as anode materials for lithium-ion batteries.
Porous carbons such as CMK-3 are commonly used as matrices to accommodate metal oxides for the improvement of their electrochemical performance. However, the mesostructure of CMK-3 may be destroyed gradually with the increase of metal oxide content and some particles are inevitably formed outside the pores of CMK-3, leading to a gradual decrease in capacity and poor cycling performance. Herein, graphene-encapsulated CMK-3-metal oxides (Fe3O4 and NiO) are synthesized through a stepwise heterocoagulation method and exhibit improved electrochemical performances compared to uncoated CMK-3-metal oxides. The core-shell structure of these novel composites can protect the metal oxide particles on the surface of CMK-3 and avoid the aggregation of porous carbon-metal oxides. Moreover, the introduction of graphene may stabilize the mesostructure of CMK-3 during lithiation and delithiation processes and improve the electronic conductivity of the composite, which are conducive to enhancing electrochemical performances of porous carbon-supported metal oxides.
Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China.
Shanshan
S
Tao
Wenbo
W
Yue
Meiyan
M
Zhong
Zhaojing
Z
Chen
Yu
Y
Ren