Interdependence of the electrical performance of NiCuFeCoMn multi-structure carbonates as electrode material for supercapacitors

Mesoporous NiCuFeCoMn multi-structure compounds were grown as cathodes for supercapacitors using a hydrothermal method. A multi-structure electrode was constructed using a variety of nanostructures by varying the reaction time. These diverse nanostructures were highly beneficial in achieving a high electrical performance by increasing the electrode/electrolyte contact area and shortening the ion diffusion path. Optimized multi-structure arrays, which were heated for 12 h, had an excellent maximum specific capacitance of 1241 F g−1 at 3 A g−1, significantly greater than that of the other electrodes. Furthermore, the multi-structure electrode exhibited exceptional cycling stability, with 84.7% retention of the original capacitance after 5000 cycles. Moreover, an asymmetric supercapacitor with the optimized multi-structure compound as the positive electrode and graphene as the negative electrode demonstrated a high energy density of 61 W h kg−1 at a power density of 1017 W k g−1 and exceptional cycling stability by retaining 88.5% of the initial capacity after 5000 cycles. Additionally, the as-obtained asymmetric supercapacitor was capable of powering an LED light. Thus, in terms of electrical performance, the asymmetric supercapacitor fabricated with the NiCuFeCoMn multi-structure compounds outperformed the majority of previously reported transition-metal-based carbonate hydroxide asymmetric supercapacitors.