Synthesis, characterizations and electrochemical performances of anhydrous CoC₂O₄ nanorods for pseudocapacitive energy storage applications

Abstract

With active participation of Co2+/3+ redox couples in an oxalate framework, Anhydrous CoC2O4 nanorods display a capacitance equivalent to 2116 F g−1 at 1 A g−1 current rate in the potential window of 0.3 V in aqueous 2 M KOH electrolyte.

Pseudocapacitive Behavior of Ce Modified CoO through a Galvanostatic Charge–Discharge Test: Distinguishing between Surface-Control and Diffusion-Control Current

“…Warburg impedance comes from diffusion at the related process, which once again explains the relative role of the electrochemical diffusion process in CoO/GA. 30,31 The result from AC impedance analysis is consistent with that of current analysis, that is, the addition of Ce optimizes the surface process electrochemical properties of nano-CoO, which is also present as an increase of the C s value.…”

Synthesis, Characterizations, and Electrochemical Performances of Highly Porous, Anhydrous Co0.5Ni0.5C2O4 for Pseudocapacitive Energy Storage Applications

“…According to the charge storage mechanism, pseudocapacitors have access to different oxidation states for redox charge transfer that can enable higher energy density compared to EDLC. , To increase higher energy density, an asymmetry cell shows better performance when the capacitor component stores electrochemical energy by electrostatic force, and the battery component enhances the electron transfer in the hybrid electrode system, which leads to better charge transfer reaction at high current rates . Many studies are being carried out on transition metal oxide-based materials such as NiO, V 2 O 5 , spinel Co 3 O 4 , Fe 2 O 3 , and mixed spinel NiCo 2 O 4 to explore electrodes for the pseudocapacitor. − However, structural instability and performance degradation issues related to transition metal oxide lead to investigation of the novel framework structure for higher surface charge storage and better structural stability. − Metal–organic frameworks (MOFs) are used as an interesting open framework structure, where materials are constructed by joining metal-containing units with organic linkers, generating an interesting three-dimensional or two-dimensional network with permanent porosity . Highly porous metal–organic framework structures, especially utilizing an oxalate linker with active participation metal ion redox, are known to show faradic pseudocapacitive characteristics. − However, most of the oxalate materials have a high open structural space to accommodate the hydration of water, and that is why, most of the transition metal oxalates contain a structural water molecule.…”

Framework structured Ce2(C2O4)3·10H2O as a pseudocapacitive electrode of a hybrid (asymmetric) supercapacitor (HSC) for large scale energy storage applications

“…The predominant peaks at the binding energies of 531.15, 531.8, and 532.7 eV are associated with the C-O, CQO, and lattice H 2 O type oxygen (O1s), respectively. 33,36,37 Electrochemical studies All the electrochemical tests were performed in 2 M KOH electrolyte, where the Ce 2 (C 2 O 4 ) 3 Á10H 2 O and CeO 2 , obtained from the TGA studies of the cerium oxalate, were utilised as the working electrodes, using a three-electrode system, where saturated Hg/HgO (1 M KOH) was used as a reference electrode, and a platinum wire was used as the counter electrode. A CV curve was obtained in the potential range of À0.3 V to 0.5 V for a half-cell.…”

“…A reversible surface redox/ion intercalation reaction mechanism was observed for charge storage on a material containing an active redox couple for charge transfer. [30][31][32][33][34][35][36][37][38] In this work, we have successfully synthesised hydrated Ce 2 (C 2 O 4 ) 3 Á10H 2 O. An electrochemical study was carried out using an aqueous electrolyte for pseudocapacitor applications.…”