Polypyrrole-Modified NH₄NiPO₄·H₂O Nanoplate Arrays on Ni Foam for Efficient Electrode in Electrochemical Capacitors

Abstract

The growth of active materials on Ni foam was proved to be an effective strategy to enhance redox reactions for electrochemical capacitors. But for NH4NiPO4·H2O materials, a uniform nanostructure on Ni foam has not been achieved. Here, the NH4NiPO4·H2O nanoplate arrays on Ni foam are fabricated by a facile solvothermal method. To further promote the transitions of current carries and benefit the electrochemical reactions, the surfaces of NH4NiPO4·H2O nanoplate arrays were modified by a thin layer of polypyrrole through an in situ chemical polymerization method. The polypyrrole-modified NH4NiPO4·H2O nanoplate arrays on Ni foam showed much enhanced specific capacitance in comparison with the bare NH4NiPO4·H2O nanoplate arrays. When employing polypyrrole-modified NH4NiPO4·H2O/Ni foam as a positive electrode and activated carbon as a negative electrode to assemble the asymmetric supercapacitor cells, favorable capacitance and cycling ability were achieved. Such a fabrication provides a feasible method to construct efficient electrodes for sustainable electrochemical energy storage.

Hierarchical ultrathin NiAl layered double hydroxide nanosheet arrays on carbon nanotube paper as advanced hybrid electrode for high performance hybrid capacitors

“…7e. The device displays a gradually declining behavior during the first 2000 cycles and then the specific capacity almost remains unchanged in the subsequent 3000-cycle test (with a specific capacity retention of 78%), which is comparable to reported HSCs in the literature such as Ni(OH) 2 -MnO 2 //RGO (76% after 3000 cycles) [42], NH 4 NiPO 4 ·H 2 O@PPy-NF//AC (71.6% after 5000 cycles) [43] and PPy@MoO 3 //AC (83% after 600 cycles) [44].…”

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