Unveiling redox-boosted mesoporous Co@NiO-SiO2 hybrid composite with hetero-morphologies as an electrode candidate for durable hybrid supercapacitors

The nanoscale morphology and mesoporosity have a substantial effect on the energy storage properties because they offer a high surface area and porous nature. The former one bestows the accessibility of more redox-active sites, while the latter facilitates the easy entry of foreign atoms. In this report, we rationally synthesized the mesoporous NiO-SiO2 material with hetero-morphologies by a simple wet-chemical method, followed by calcination. The hetero-morphologies include nanospheres, nanoflakes, and nanoparticles collectively increased the surface area. To further increase the redox activity, the cobalt was hydrothermally doped to the NiO-SiO2 material (Co@NiO-SiO2). Consequently, the Co@NiO-SiO2 electrode demonstrated superior electrochemical response with a higher capacity of 41.7 mAh cm(-2) compared to the NiO-SiO2 electrode (25 mAh cm(-2)) in a three-electrode system. Moreover, the Co@NiO-SiO2 electrode was sustained up to 10,000 cycles by retaining 95.5% of its initial capacity. The ability of the Co@NiO-SiO2 material to-wards practical applicability was also unveiled by fabricating a hybrid supercapacitor (HSC). The HSC delivered a notable energy density (42.3 mWh cm(-2)) and power density (10.2 mW cm(-2)). Furthermore, the HSC exhibited outstanding durability (10,000 cycles) without fading. The ability of HSC was also tested by energizing light-emitting diodes. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

The nanoscale morphology and mesoporosity significantly affect the energy storage properties by providing high surface area and porous nature. Rational synthesis of mesoporous NiO-SiO2 material with hetero-morphologies, along with cobalt doping, enhances electrochemical response, capacity, and cycling performance. The hybrid supercapacitor (HSC) fabricated from Co@NiO-SiO2 material exhibits notable energy density, power density, and outstanding durability, showing potential for practical applications.