Two-Dimensional Hexagonal-Shaped Mesoporous Carbon Sheets for Supercapacitors

Abstract

Two-dimensional mesoporous hexagonal carbon sheets (MHCSs) have been prepared via a chemical vapor deposition method employing mesoporous Mg(OH) 2 hexagonal sheets as the template and acetylene gas as the carbon precursor. MHCSs with porosity in the micropore–mesopore range have a high specific surface area of 1785 m 2 ·g –1 . The hierarchical microporous–mesoporous pore structure enables rapid ion transport across the hexagonal carbon sheets, resulting in superior electrochemical performance. The MHCS electrodes showed a maximum specific capacitance of 162 F·g –1 at 5 mV s –1 using the electrolyte 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI). MHCS symmetric coin cells exhibited a maximum energy density of 67 Wh·kg –1 at 0.5 A·g –1 and a maximum power density of 14.97 kW·kg –1 at 10 A·g –1 .

Carbon fiber composite electrodes derived from metal organic polyhedra-18 and matrimid for hybrid supercapacitors

“…16,[19][20][21][22] Hybrid supercapacitors have the potential to bring a well-balanced synergistic combination of both EDLC and pseudocapacitors to simultaneously afford superior energy density, power density, and cyclability. [23][24][25][26][27][28][29] Hybrid supercapacitor electrodes generally consist of a composite/physical mixture of carbon-based EDLC components along with a metal/metal oxide or conducting polymer pseudocapacitive component. [30][31][32][33][34][35] The EDLC part of the electrode mainly contributes conductivity and power density while pseudocapacitive materials add energy density.…”

“…[23][24][25][26][27][28][29] Hybrid supercapacitor electrodes generally consist of a composite/physical mixture of carbon-based EDLC components along with a metal/metal oxide or conducting polymer pseudocapacitive component. [30][31][32][33][34][35] The EDLC part of the electrode mainly contributes conductivity and power density while pseudocapacitive materials add energy density. 4 Combining EDLCs and PCs in a way that enhances the other is the major challenge in designing hybrid supercapacitor electrodes.…”

Vanadium Sesquioxide/Nitride Nanostructures in Electrospun Carbon Fibers for High Energy Density Supercapacitors

“…Electrochemical capacitors (ECs), especially electric doublelayer capacitors (EDLCs), which store charge through the electrostatic adsorption and desorption of ions at the electrode and electrolyte interface, have significantly more power than considerably slower batteries. 1 Supercapacitors work best for applications that need energy bursts over a period of seconds or tens of seconds. However, EDLCs have low energy densities because their capacitance is mostly determined by the electrochemically accessible surface area of carbon materials.…”