Layered double hydroxides/prussian blue analogs toward improved capacitive performances.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Nickel-based bimetallic hydroxides are promising supercapacitor electrodes due to high theoretical capacitance and cost-effectiveness.
• Challenges include low conductivity and volume expansion during cycling, limiting their practical application.

Purpose of the Study:

• To enhance the performance and stability of nickel-based supercapacitor electrodes.
• To develop a novel electrode material by combining NiCo-layered double hydroxides (NiCo-LDH) with Prussian blue analogs (PBA).

Main Methods:

• Electrodeposition of NiCo-LDH nanosheets onto nickel foam (NF).
• Surface modification of NiCo-LDH with PBA via ion exchange to form NiCo-LDH/PBA.
• Optimization of ion exchange duration to achieve a flower-like morphology.

Main Results:

• The optimal NiCo-LDH/PBA electrode exhibited high specific capacitances of 1973.0 F g^-1 at 2 A g^-1 and 1604.4 F g^-1 at 10 A g^-1.
• Asymmetric supercapacitors using NiCo-LDH/PBA achieved an energy density of 66.3 Wh kg^-1 at 725.0 W kg^-1.
• The integrated PBA improved structural stability and reduced agglomeration during cycling.

Conclusions:

• The NiCo-LDH/PBA composite electrode demonstrates superior electrochemical performance and cycling stability.
• This material is a promising candidate for advanced supercapacitor electrodes.
• The strategy of combining LDH with PBA offers a viable route for developing high-performance energy storage devices.