Hydrogenated NiO nanoblock architecture for high performance pseudocapacitor.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitors are crucial energy storage devices.
• Nickel oxide (NiO) is a promising electrode material.
• Improving NiO's electrochemical performance is an active research area.

Purpose of the Study:

• To fabricate and characterize supercapacitor electrodes using self-organized 3D architecture of hydrogenated NiO (H-NiO) nano-blocks (NBs).
• To evaluate the electrochemical performance of H-NiO NBs compared to pure NiO NBs.
• To understand the role of hydrogenation in enhancing electrode properties.

Main Methods:

• Fabrication of NiO and H-NiO NBs via electrodeposition and high-temperature annealing on a Ni foil/Cu substrate.
• Electrochemical characterization including cyclic voltammetry, galvanostatic charge-discharge, and cycling stability tests.
• Analysis of specific capacitance, areal capacitance, rate capability, energy density, and power density.

Main Results:

• H-NiO NBs electrode demonstrated superior specific capacitance (~1272 F g⁻¹) and areal capacitance (~371.8 mF cm⁻²) compared to NiO NBs (~865 F g⁻¹ and ~208.2 mF cm⁻²).
• Excellent cycling stability with only 5.3% capacitance loss after 3000 cycles at 1.1 A g⁻¹.
• High rate capability with 61% capacity retention at 111.11 A g⁻¹ and impressive energy (13.51 Wh kg⁻¹) and power (19.44 kW kg⁻¹) densities.

Conclusions:

• The self-organized 3D architecture of H-NiO NBs significantly enhances supercapacitor performance.
• Hydrogenation and the resulting hydroxyl group incorporation improve electron and ion conductivity, leading to superior pseudocapacitive behavior.
• H-NiO NBs represent a highly effective material for next-generation supercapacitors.