Hierarchical core-shell electrode with rGO wrapped NiWO4 nanowire arrays on Ni foam for high-performance asymmetric supercapacitors

Abstract

This paper presents a novel class of hierarchical core-shell nanowire arrays (NWAs) that may greatly enhance the electrochemical storage of energy capabilities of supercapacitors. These NWAs consist of rGO sheets surrounding a NiWO4 nanowire core. The average surface area of NiWO4 nanoparticles was 105.7 m2/g, and their sizes ranged from 20 to 100 nm. The NWO/rGO composite has an impressive specific capacitance of up to 1156 F g−1 at 1 A g−1 current density. The synergistic impact of NiWO4 and rGO, which offer conducting channels and active sites, is responsible for the NWO/rGO electrode's significantly improved capacitive performance. This hybrid electrode has a lot of promise for use in energy storage devices since the cyclic stability tests showed that its starting values did not decline after 5000 cycles. In a three-electrode system, the NiWO4/rGO electrode provides more energy density compared to the NiWO4 electrode because to a boost in specific capacitance and a wider potential window (1 V for nanocomposite NiWO4/rGO vs. 0.6 V for NiWO4). Electrodes made of a nanocomposite of NiWO4 and rGO are used to construct a symmetric capacitor. Both the asymmetric and symmetric capacitors function similarly when driven within a 1.5 V potential region. On top of that, the device achieved a power density of 932 W kg−1 and an energy density of 42 Wh kg−1.