The critical role of nanostructured carbon pores in supercapacitors

Hydrothermal synthesis of hierarchical microstructure tungsten oxide/carbon nanocomposite for supercapacitor application

“…Mesopores (ranging from 2 to 50 nm based on the IUPAC categorization) play a crucial role in enabling the migration of ions towards smaller micropores (those less than 2 nm in size). These facilitate the smooth transportation of ionic substances and the interconnected pore structure supports the formation of an electric double-layer during the charging process 46 . The surface area and pore volume, calculated by the density functional theory (DFT) method, were 4.1 m 2 /g and 0.02 cc/g for WO 3 while 58.5 m 2 /g and 0.09 cc/g for WO 3 /C nanocomposite.…”

Iron MOF-Derived Fe2O3/NPC Decorated on MIL-88A Converted Fe3C Implanted Electrospun Porous Carbon Nanofibers for Symmetric Supercapacitors

“…The CV curves of the Fe 2 O 3 /NPC-350@Fe 3 C/EPCNFs (Figure a) exhibited a semi-rectangular shape, and a small hump was observed in the CV curve at 10 mV s –1 , which disappeared as the scan rate increased, suggesting that the capacitive behavior observed was the result of a combination of the electric double-layer capacitance (EDLC) of carbon nanoparticles and the pseudocapacitance stemming from reversible faradaic redox reactions of the Fe 3+ /Fe 2+ couple in Fe 2 O 3 . , Both the non-faradaic charging process, which results from the electrochemical adsorption of K + on the surface of carbon and Fe 2 O 3 , and the reversible faradaic redox charging process, which results from the oxidation state conversion between Fe 3+ and Fe 2+ , are shown below: , Moreover, the CV curves of the Fe 2 O 3 /NPC-350@Fe 3 C/EPCNFs electrode exhibit a larger response current because of the formation of γ-Fe 2 O 3 and β-Fe 2 O 3 after the thermal oxidation process . Additionally, the nanoporous carbon stemming from the alteration of Fe-MOFs and integrated MIL-88A could effectively enhance the conductivity and increase the number of active sites, resulting in an improvement in the capacitance of the Fe 2 O 3 /NPC-350@Fe 3 C/EPCNFs electrode. − When the scan speed was increased, both the area of the cyclic voltammetry (CV) curve and the current density were increased. However, the overall shape of the CV curve remained consistent, with slight shifts in the redox peaks.…”

Carbon quantum dots modified and Y3+ doped Ni3(NO3)2(OH)4 nanospheres with excellent battery‐like supercapacitor performance

“…Supercapacitors are widely used in the field of energy storage because of their ultra‐high specific capacitance, high power density, excellent cycling performance, and other advantages [1] . The capacitance performance and energy density of supercapacitors are closely related to the electrode materials, so selecting electrode materials is essential [2] . Transition metal oxides have attracted great interest among electrode materials owing to their abundant valence states and high theoretical specific capacitance [3] .…”

“…[1] The capacitance performance and energy density of supercapacitors are closely related to the electrode materials, so selecting electrode materials is essential. [2] Transition metal oxides have attracted great interest among electrode materials owing to their abundant valence states and high theoretical specific capacitance. [3] Nickel-based compounds such as Ni 3 (NO 3 ) 2 (OH) 4 and α-Ni(OH) 2 have been widely investigated as high-performance battery-type supercapacitors because of their low cost, environmental friendliness, and high theoretical specific capacitance.…”