Assembly of core-shell structured porous carbon-graphene composites as anode materials for lithium-ion batteries

As potential anode materials for lithium-ion batteries, mesoporous carbons such as CMK-3 and CMK-8 usually show stable cycling performances but only slightly higher reversible capacities than commercial graphite. Graphene has much higher theoretical capacity than that of graphite in theory. However, its electrochemical behavior is not as good as expected due to the aggregation of graphene nanosheets. Herein we describe a novel strategy for the preparation of core-shell structured porous carbon-graphene composites. Compared to pure porous carbons or pure graphene nanosheets, these novel composites exhibit superior electrochemical performances including higher reversible capacities and better cycle/rate performances. This core-shell structure can avoid the aggregation of graphene nanosheets as well as may stabilize the mesostructure of porous carbon, which is beneficial to improving the electrochemical performances of the composites.