posted on 2024-02-22, 22:04authored byNavid Noor, Thomas Baker, Hyejin Lee, Elliot Evans, Shayan Angizi, Jeffrey Daniel Henderson, Amirhossein Rakhsha, Drew Higgins
Carbon-based supercapacitor
electrodes are generally restricted
in energy density, as they rely exclusively on electric double-layer
capacitance (EDLC). The introduction of redox-active organic molecules
to obtain pseudocapacitance is a promising route to develop electrode
materials with improved energy densities. In this work, we develop
a porous nitrogen-doped reduced graphene oxide and 9,10-phenanthrenequinone
composite (N-HtrGO/PQ) via a facile one-step physical adsorption method.
The electrochemical evaluation of N-HtrGO/PQ using cyclic voltammetry
showed a high capacitance of 605 F g–1 in 1 M H2SO4 when the composite consisted of 30% 9,10-phenanthrenequinone
and 70% N-HtrGO. The measured capacitance significantly exceeded pure
N-HtrGO without the addition of redox-active molecules (257 F g–1). In addition to promising capacitance, the N-HtrGO/30PQ
composite showed a capacitance retention of 94.9% following 20,000
charge/discharge cycles. Based on Fourier transform infrared spectroscopy,
we postulate that the strong π–π interaction between
PQ molecules and the N-HtrGO substrate enhances the specific capacitance
of the composite by shortening pathways for electron transfer while
improving structural stability.