Designing of two dimensional lanthanum cobalt hydroxide engineered high performance supercapacitor for longer stability under redox active electrolyte

Fabrication of 3D HierarchicalSphericalHoneycomb-Like Nd2O3/Co3O4/Graphene/Nickel Foam Composite Electrode Material for High-Performance Supercapacitors

A 3D hierarchical spherical honeycomb-like composite electrode materialof neodymium oxide (Nd₂O₃), cobalt tetraoxide (Co₃O₄), and reduced graphene oxide (rGO) on nickel foam (named as Nd₂O₃/Co₃O₄/rGO/NF) were successfully fabricated by combining the hydrothermal synthesis method and the annealing process. Nickel foam with a three-dimensional spatial structure was used as the growth substrate without the use of any adhesives. The Nd₂O₃/Co₃O₄/rGO/NF composite has outstanding electrochemical performance and can be used directly as an electrode material for supercapacitors (SCs). By taking advantage of the large specific surface area of the electrode material, it effectively slows down the volume expansion of the active material caused by repeated charging and discharging processes, improves the electrode performance in terms of electrical conductivity, and significantly shortens the electron and ion transport paths. At a 1 A/g current density, the specific capacitance reaches a maximum value of 3359.6 F/g. A specific capacitance of 440.4 F/g with a current density of 0.5A/g is still possible from the built symmetric SCs. The capacitance retention rate is still 95.7% after 30,000 cycles of testing at a high current density of 10 A/g, and the energy density is 88.1 Wh/kg at a power density of 300 W/kg. The outcomes of the experiment demonstrate the significant potential and opportunity for this composite material to be used as an electrode material for SCs.

3D hierarchical cobalt vanadate nanosheet arrays on Ni foam coupled with redox additive for enhanced supercapacitor performance

Room-temperature synthesized 3D hierarchical cobalt vanadate (Co₃V₂O₈) nanosheet arrays on Ni foam for use as supercapacitor electrode is presented. In a 3 M KOH electrolyte, the electrode exhibits a capacitance of 109.9 mA h g^-1 (878.9 F g^-1) at a current density of 1 A g^-1. The capacitance is enhanced to 198.1 mA h g^-1 (1584.5 F g^-1) at 1 A g^-1 through the addition of 0.05 M redox-additive K₃[Fe(CN)₆] into the KOH electrolyte. Furthermore, the Co₃V₂O₈/activated carbon asymmetric supercapacitor cell with the advanced electrolyte outperforms most reported Co₃V₂O₈-based electrodes with a remarkable energy density of 55.5 W h kg^-1 at an 800 W kg^-1 power density. Combining a facile synthetic strategy and excellent electrochemical performance, the obtained Co₃V₂O₈ exhibits potential for practical application.

Fabrication of a composite material of Gd2O3, Co3O4 and graphene on nickel foam for high-stability supercapacitors

The Gd2O3/Co3O4/rGO/NF electrode was prepared using a one-step hydrothermal method and annealing process, with high specific capacitance and excellent cycle stability.

Fabrication of honeycomb-structured composite material of Pr2O3, Co3O4, and graphene on nickel foam for high-stability supercapacitors

The Pr2O3/Co3O4/rGO/NF electrode has been prepared by hydrothermal method and annealing process, with high specific capacitance and excellent cycle stability.