Fabrication of porous nanosheets assembled from NiCo₂O₄/NiO electrode for electrochemical energy storage application

In this work, The NiCo₂O₄/NiO electrode materials are successfully synthesized via hydrothermal and following calcination approach. Due to the distinctive porous nanosheets assembled structure through controlling effectively the feeding amount of HMT, the NiCo₂O₄/NiO electrode possesses excellent specific surface area and reasonable pore size distribution, which hence minimizes the intrinsic electrode resistance and improves the morphology and structure stability. Therefore, the NiCo₂O₄/NiO electrode delivers a superior specific capacitance (Csp) (992.85 F g⁻¹ at the current density of 1 A g⁻¹), good rate capability (79.14% Csp retention even at 10 A g⁻¹) and considerable cycle life (79.82% Csp retention at 10 A g⁻¹ after 5000 times). Furthermore, the asymmetric supercapacitor is successfully assembled by NCN-0.1 as positive electrode and activated carbon (AC) as negative electrode. The NCN-0.1//AC device delivers a relatively excellent energy density of 47.43 kW kg⁻¹ at a power density of 0.389 W h kg⁻¹. Consequently, the outstanding performance and stability of the ASC device shows great potential for future energy storage application.