DFT calculation for the electronic properties and quantum capacitance of
pure and doped Zr2CO2 as electrode of supercapacitors
Defect and doping are effective methods to modulate the physical and
chemical properties of materials. In this report, we investigated the
structural stability, electronic properties and quantum capacitance
(Cdiff) of Zr2CO2 by changing the dopants of Si, Ge, Sn, N, B, S and F
in the substitutional site. The doping of F, N, and S atoms makes the
system undergo the semiconductor-to-conductor transition, while the
doping of Si, Ge, and Sn maintains the semiconductor characteristics.
The Cdiff of the doped systems are further explored. The B-doped system
can be used as cathode materials, while the systems doped by S, F, N, Sn
atoms are promising anode materials of asymmetric supercapacitors,
especially for the S-doped system. The improved Cdiff mainly originates
from Fermi-level shifts and Fermi-Dirac distribution by the introduction
of the dopant. The effect of temperature on Cdiff is further explored.
The result indicates that the maximum Cdiff of the studied systems
gradually decreases with the increasing temperature. Our investigation
can provide useful theoretical basis for designing and developing the
ideal electrode materials for supercapacitors.