A review of nitrogen-doped carbon materials for lithium-ion battery anodes

One of the most important research areas related to Li-ion batteries is the replacement of the graphite anode with other carbon materials such as hard carbons, activated carbons, carbon nanotubes, graphene, porous carbons, and carbon fibers. Although such materials have shown better electrochemical performance for lithium storage compared to graphite, there is plenty of room for improvement. One of the most effective approaches is to dope heteroatoms (e. g. nitrogen) in the structure of the carbon materials to improve their electrochemical performance when they are used as anode materials. We first describe how N-doping has a positive effect on lithium storage and then provide numerous selected examples of this approach being applied to various carbon materials. The characterization of N doped in the structure of different carbon materials by X- ray photoelectron spectroscopy and scanning tunneling microscopy is then presented since they are able to characterize the N in these structures with a high (atomic) resolution. Finally, a statistical analysis is performed to show how the amount of doped N affects the specific capacity of the N-doped carbon materials.