1 research outputs found
On the Origin of the Enhanced Supercapacitor Performance of Nitrogen-Doped Graphene
Graphene-based electrodes have been
widely tested and used in electrochemical
double layer capacitors due to their high surface area and electrical
conductivity. Nitrogen doping of graphene has recently been demonstrated
to significantly enhance capacitance, but the underlying mechanisms
remain ambiguous. We present the doping effect on the interfacial
capacitance between graphene and [BMIM]Â[PF<sub>6</sub>] ionic liquid,
particularly the relative changes in the double layer and electrode
(quantum) capacitances. The electrode capacitance change was evaluated
based on density functional theory calculations of doping-induced
electronic structure modifications in graphene, while the microstructure
and capacitance of the double layers forming near undoped/doped graphene
electrodes were calculated using classical molecular dynamics. Our
computational study clearly demonstrates that nitrogen doping can
lead to significant enhancement in the electrode capacitance as a
result of electronic structure modifications while there is virtually
no change in the double layer capacitance. This finding sheds some
insight into the impact of the chemical and/or mechanical modifications
of graphene-like electrodes on supercapacitor performance