| Abstrakt: |
Although the transition metal sulfides have shown persuasive proof and stellar traits for energy storage applications, their real applications still possess some obstacles such as prolonged ionic and electronic transport. Hence, NiCo2S4decorated a pyrolyzed hydrogel (NiCo2S4@PHG) viafacile synthesis is considered a promising electrocatalyst for energy storage devices. The prepared electrode materials were characterized utilizing different analysis techniques like XPS, XRD, FT-IR, TGA, SEM, TEM, elemental mapping and EDX that reveal the crucial role of the hydrogel pyrolysis in creating a homogenous nitrogen-doped carbon matrix. The as-fabricated 0.5 NiCo2S4@PHG nanocomposite was electrochemically examined in a sealed workstation cell and showed a clear battery-type supercapacitor behavior attributed to various redox reactions, porosity, and conductivity that was enhanced by self-doped nitrogen. In contrast, composites based on nickel and cobalt sulfides individually with pure hydrogel demonstrated the superiority of binary metal composites. The 0.5 NiCo2S4@PHG electrode exposed a marvelous specific capacity of 317.9 mAh g−1and capacitance of 2728.5 F g−1at a current density of 1 A g−1. A hybrid asymmetric supercapacitor was established by 0.5 NiCo2S4@PHG (cathode) and activated carbon (AC, anode), which brought large energy and power densities of 32.8 Wh kg−1and 750 W kg−1, respectively. The fabricated cell manifests ultra-high retention of 82.6 % at a current density of 20 A g−1after 10,000 cycles. These outstanding accomplishments hold significant potential for practical energy storage and conversion applications. |
Full Text from ScienceDirect