Ultrathin α-Ni(OH)2 nanosheets coated on MOF-derived Fe2O3 nanorods as a potential electrode for solid-state hybrid supercapattery device

Abstract

The versatility of supercapacitors in energy storage applications has garnered much interest. Specifically, to improve the energy density by combining with the outstanding power density in higher energy density batteries to appear as supercapattery. Herein, for the first time, we propose a Fe2O3/α-Ni(OH)2 as an electrode for solid-state hybrid supercapattery. We construct ultrathin α-Ni(OH)2 nanosheets coated on MOF-derived Fe2O3 via the chemical bath method. The Fe2O3/α-Ni(OH)2 composite exhibits excellent electrochemical properties, including high specific capacity around 511.5 C/g (930 F/g) at 1 A/g with outstanding cycle stability (88.3%, 10,000th cycles) and the porosity of the material reveals a good surface area of 202 m2/g. The kinetic analysis reveals that Fe2O3@α-Ni(OH)2 exhibits diffusion-controlled faradaic behaviour (51% diffusion-controlled contributions). As a hybrid supercapattery, the Fe2O3@α-Ni(OH)2//Activated carbon exhibits a specific energy density of 44.51 Wh/kg and specific power density of 2465 W/kg and excellent long-term cycling stability (keep over 90.5% of the initial specific capacitance after 4000 cycles). Three prototype hybrid supercapattery devices (Fe2O3@α-Ni(OH)2(+)||Activated carbon(−)) connected in series were used to demonstrate red LED lighting. This study offers a unique approach to constructing high-performance, low-cost, and ecological green energy storage systems.