Understanding the crystal structure-dependent electrochemical capacitance of spinel and rock-salt Ni–Co oxides via density function theory calculations

Abstract

The crystal structure dependent pseudocapacitance of binary spinel and rock-salt Ni–Co oxides is unveiled via the density function theory calculations, along with experimental evaluation.

Nickel Foam-Supported NiCo2O4 Urchin-Shaped Microparticles Sheathed with NiCoO2 Nanosheets as Electrolyte-Wettable Electrodes for Supercapacitors

“…The contact angle was drastically reduced after the growth of the composite structures on the foam, indicating a transition to superhydrophilicity. We have also analyzed the time-dependent infiltration behavior of aqueous KOH electrolyte on the NCO-nco/NF to validate the earlier computational study 20 predicting enhanced KOH adsorption in the nco phase (NiCoO 2 ). Figure 6 depicts the penetration behavior of KOH droplets on the NCO-nco surface.…”

“…A theoretical study employing DFT calculations compared the electrolyte adsorption capacity of NiCo 2 O 4 and NiCoO 2 in KOH electrolyte wherein hydroxyl adsorption is favored at Ni/ Co and the bridge sites of the NiCoO 2 (100) plane, making the material the choice of the sheath in our present study. 20 The advantages of the NiCo 2 O 4 scaffold have been previously validated by many research teams. 18,21 Based on the leads from the reported literature, we have fabricated 3D hierarchical NiCo 2 O 4 −NiCoO 2 structures on NF with NiCo 2 O 4 urchins as the scaffold and NiCoO 2 nanosheets around them as the sheath.…”

Mesoporous carbon-supported flower-like Mn-doped Ni–Co layered double hydroxides with high cycling capacitance retention for supercapacitors

“…To correct the Coulomb interaction effect on transition metal elements, the DFT + U eff method was used, with a U eff value of 3.3, 5.5 and 5.2 eV for Co, Ni and Mn, respectively. [68][69][70] The adsorption energy of *OH and desorption energy of *H were calculated using the following equations: 71…”

Crystalline phase transformation of Co-MOF derivatives on ordered mesoporous carbons for high-performance supercapacitor applications

“…DFT+U calculations were used to correct the coulombic interaction effect on transition-metal elements, with a U–J value of 3.3 eV for Co and 5.5 eV for Ni. 24,25 The adsorption energy of *OH and disadsorption energy of *H were calculated using the following equations: 26 …”