An assembled-nanosheets discus-like Ni(OH)2 hierarchical structure as a high performance electrode material for supercapacitors

Abstract

An assembled-nanosheets discus-like Ni(OH)₂ hierarchical structure is synthesized through a facile solvothermal method without any surfactant used in the synthesis. The morphology and microstructure of the Ni(OH)₂ products can be tuned using the solvothermal temperature. The as-prepared Ni(OH)₂ samples are investigated as electrode materials for supercapacitors. It is found that the assembled-nanosheets Ni(OH)₂ hierarchical structure exhibits excellent capacitive performance with a specific capacitance as high as 1830.3 F g⁻¹ at a current density of 1.0 A g⁻¹, great electrochemical stability with a capacitance retention of 98.9% after 1000 cycles at a constant current density of 10 A g⁻¹, and a high energy density of 146.4 W h kg⁻¹. The remarkable capacitive performance can be attributed to the unique hierarchical structure of the Ni(OH)₂ product, which can facilitate the penetration and migration of electrolyte ions, shorten the diffusion distance of charges and increase the utilization of active materials. The excellent capacitive performance makes the Ni(OH)₂ hierarchical architecture a promising electrode material for electrochemical energy storage applications.