Ni3S4 nanoparticle decorated Mn doped Co(OH)2 nanosheets as electrodes of hybrid supercapacitors with high energy density and long-term cycle stability

Due to their outstanding electrochemical properties, transition metal sulfides and hydroxides are often used as high-performance electrode materials for supercapacitors. The Mn-doped Co(OH)2/Ni3S4 electrode ma-terial in this study, due to the synergistic reaction mechanism among Co(OH)2 and Ni3S4 and the increased active sites by the addition of Mn, the Mn-Co(OH)2/Ni3S4 exhibits excellent electrochemical property. The electrochemical performance of the Mn-Co(OH)2/Ni3S4 hybrid electrode was measured in an electrode cell made of 2 M KOH solution, showing a superior specific capacitance of 1107.0 C g-1 at 0.5 A g-1, in addition to the excellent capacity retention rate at 10 A g-1 is 72.7 % of that at 1 A g-1. The performance of the hybrid supercapacitor (HSC) assembled with Mn-Co(OH)2/Ni3S4 compound and activated carbon (AC) was mea-sured under the same electrolyte conditions, anwell-specificific capacity (157.2 F g-1 at 0.5 A g-1) was achieved, along with superior long-term stable charge/discharge capability (88.9 % of the original specific capacity after 35,000 cycles at 8 A g-1). Meanwhile, the most practical application is when the power density of 410.4 W kg-1, the assembled HSC device has an energy storage capacity of 58.8 W h kg-1, re-vealing that the developed Mn-Co(OH)2/Ni3S4 has great application potential for supercapacitors in the future.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

Due to the synergistic reaction mechanism among Co(OH)2 and Ni3S4 and the increased active sites by the addition of Mn, the Mn-Co(OH)2/Ni3S4 electrode material exhibits excellent electrochemical properties, including a superior specific capacitance of 1107.0 C g-1 and a capacity retention rate of 72.7% at 10 A g-1. When combined with activated carbon, the Mn-Co(OH)2/Ni3S4 compound achieves a specific capacitance of 157.2 F g-1 and retains 88.9% of its original capacity after 35,000 cycles at 8 A g-1. Furthermore, the assembled hybrid supercapacitor device shows an energy storage capacity of 58.8 W h kg-1 at a power density of 410.4 W kg-1, indicating the great application potential of Mn-Co(OH)2/Ni3S4 in the future.