Concave Ni(OH)2 Nanocube Synthesis and Its Application in High-Performance Hybrid Capacitors

The controlled synthesis of hollow structure transition metal compounds has long been a very interesting and significant research topic in the energy storage and conversion fields. Herein, an ultrasound-assisted chemical etching strategy is proposed for fabricating concave Ni(OH)(2) nanocubes. The morphology and composition evolution of the concave Ni(OH)(2) nanocubes suggest a possible formation mechanism. The as-synthesized Ni(OH)(2) nanostructures used as supercapacitor electrode materials exhibit high specific capacitance (1624 F g(-1) at 2 A g(-1)) and excellent cycling stability (77% retention after 4000 cycles) due to their large specific surface area and open pathway. In addition, the corresponding hybrid capacitor (Ni(OH)(2)//graphene) demonstrates high energy density (42.9 Wh kg(-1) at a power density of 800 W kg(-1)) and long cycle life (78% retention after 4000 cycles at 5 A g(-1)). This work offers a simple and economic approach for obtaining concave Ni(OH)(2) nanocubes for energy storage and conversion.

Automated summary

This research proposes an ultrasound-assisted chemical etching strategy to fabricate concave Ni(OH)(2) nanocubes and analyzes their morphology and composition evolution. The synthesized Ni(OH)(2) nanostructures show high specific capacitance and excellent cycling stability as supercapacitor electrode materials, while the corresponding hybrid capacitor exhibits high energy density and long cycle life.