Nickel-Cobalt Hydroxides with Tunable Thin-Layer Nanosheets for High-Performance Supercapacitor Electrode.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Layered double hydroxides (LDHs) are promising supercapacitor electrode materials.
• Controlling LDH nanostructure is crucial for superior energy storage performance.

Purpose of the Study:

• To prepare diverse nickel-cobalt layered double hydroxides (NiCo-LDHs) using a facile one-step hydrothermal method.
• To investigate the effect of urea content on NiCo-LDH nanostructure and electrochemical properties.
• To optimize NiCo-LDH nanostructure for enhanced supercapacitor performance.

Main Methods:

• One-step hydrothermal synthesis of NiCo-LDHs with varying urea concentrations.
• Characterization of NiCo-LDH nanostructures (thickness, porosity).
• Electrochemical testing of supercapacitor performance (specific capacitance, cycling stability).

Main Results:

• Decreased urea content refined NiCo-LDH nanostructures, improving dispersibility, reducing thickness to 1.62 nm, and optimizing pore structure.
• NiCo-LDH-1 (low urea) achieved ultra-high specific capacitance (3982.5 F g⁻¹ at 1 A g⁻¹) and excellent cycling stability (>93.6% retention after 1000 cycles at 10 A g⁻¹).
• Asymmetric supercapacitors demonstrated high performance (95 F g⁻¹ at 1 A g⁻¹, 78% retention over 1000 cycles).

Conclusions:

• Urea content is a critical factor in controlling NiCo-LDH nanostructure and supercapacitor performance.
• Optimized NiCo-LDHs offer a promising pathway for developing high-performance energy storage devices.
• The facile synthesis method provides a viable route for scalable production of advanced supercapacitor materials.