Enhanced performance of supercapacitors by constructing a “mini parallel-plate capacitor” in an electrode with high dielectric constant materials

Abstract

As a class of highly stable materials, the application of high dielectric constant materials in the field of energy is hampered by the low electrical conductivity and poor energy storage...

Enhanced electromechanical properties in low-temperature gadolinium-doped ceria composites with low-dimensional carbon allotropes

“…53,54 This increase is explained by a mini-capacitor model consisting of a high capacitance ceramic and a conductive filler. 55,56 CNT with high conductivity is believed to form CGO exhibiting a higher dielectric constant and electrostrictive coefficient than pristine CGO and CGO–GO. It is noteworthy that, unlike the overall space charge, the surface charge between CNT and CGO significantly affects the electrostrictive coefficient by the mini-capacitor model.…”

Enhancement of the Electrochemical Performance of a Novel Binder-Free Ni3S2@Co3S4/Mn3O4-RGO Heterostructure through Crystallinity and Band Gap Modification for Flexible Supercapacitors

“…All the electrode materials showed a pair of redox peaks, suggesting the charge storage through the redox reaction on the surfaces. Improvement in the capacitive property of CSRGN as compared to CORGN was attributed to the additional capacitance contribution by Ni 3 S 2 and the presence of higher active sites for adsorption/desorption of OH – ions. − The redox peaks indicated the typical battery-type nature of the electrodes, which can be attributed to the reversible faradic reaction of Ni + /Ni 2+ and Co 2+ /Co 3+ with OH – ions of electrolytes (eqs –). , …”

Amorphous MnOx Nanostructure/Multiwalled Carbon Nanotube Composites as Electrode Materials for Supercapacitor Applications

“…Pseudocapacitive materials usually deliver a high specific capacitance and promising energy density compared to that of the classical dielectric capacitive materials because they store charge not only by the adsorption/desorption of electrolyte ions in the electrical double layer (EDL) but also via fast and reversible redox reactions at the electrode–electrolyte interface . It is generally accepted that the electrochemical performance of pseudocapacitive material is closely related with its dielectric property. , Although high dielectric constant materials are stable, they usually suffer from low electrical conductivity and poor energy storage capacity . Manganese dioxide (MnO 2 ), in particular, is considered as one of the promising transition-metal-oxide-based pseudocapacitive material because of its high energy density, good cycling stability, low cost, and environmental compatibility. , However, the achievable specific capacitance of MnO 2 in its various crystallographic form has a much lower value than the theoretical prediction (1370 F g –1 in 0.9 V potential window for one electron redox process/manganese atom) due to the poor internal conductivity (10 –5 to 10 –6 S cm –1 ) and low specific surface area resulting from the agglomeration characteristic of the nanostructures. , Physical properties like microstructure/surface morphology and chemical parameters like valence/hydrous nature are found to directly affect factors for their electrochemical performance .…”

“…1 It is generally accepted that the electrochemical performance of pseudocapacitive material is closely related with its dielectric property. 2,3 Although high dielectric constant materials are stable, they usually suffer from low electrical conductivity and poor energy storage capacity. 3 Manganese dioxide (MnO 2 ), in particular, is considered as one of the promising transition-metal-oxide-based pseudocapacitive material because of its high energy density, good cycling stability, low cost, and environmental compatibility.…”