Nano-Graphene Enclosed Multi Nitrogen: Dynamic Hierarchical Self-Assemble Property for Lithium Ion Storage

Led to significant capacity improvement to 1800 mA/h after 100 cycles for nano-graphene-N₄, which is the first report for a carbonaceous materials anode. In addition, the doping level, id est, number of nitrogen atoms, had a significant influence on the molecular self-assembled structures through hierarchical self-assembly. As the nitrogen concentration increased, the d-space between the nanosheets increased from 3.4 to 4.3. The capacity of the nano-graphene increased greatly from 500 mAh/g for nano-graphene without N-doping to 1800 mAh/g for nano-graphene with nanographene-N₄, indicating that the capacity is related to the structures, and was defined and the relationship between performance and structure was determined.