Doping heteroatoms into carbon materials is another method
to effectively tailor their intrinsic properties including the chemical
features of surfaces and the electronic characteristics [10,11].
Due to the comparable atom size and different electronegativity
with carbon, N and P doping can modify the electron transport
properties and improve the electrocatalytic activity of carbon
materials. This approach has been used to enhance the capacity
and cycling stability of LIBs [12,13].