Bimetallic-MOF Derived Accordion-like Ternary Composite for High-Performance Supercapacitors

Abstract

Supercapacitors are regarded to be highly probable candidates for next-generation energy storage devices. Herein, a bimetallic Co/Ni MOF is used as a sacrificial template through an alkaline hydrolysis and selective oxidation process to prepare an accordion-like ternary NiCo₂O₄/β-Ni _xCo_{1- x}(OH)₂/α-Ni _xCo_{1- x}(OH)₂ composite, which is composed of Co/Ni(OH)₂ nanosheets with large specific surface as the frame and NiCo₂O₄ nanoparticles with high conductivity as the insertion, for supercapacitor application. This material exhibits both high specific capacitance (1315 F·g^-1 at 5 A·g^-1) and excellent cycle performance (retained 90.7% after 10 000 cycles). This hydrolysis-oxidation process, alkali hydrolysis followed by oxidation with H₂O₂, offers a novel approach to fabricate the Ni/Co-based electrode materials with enhanced supercapacitor performance.