Unraveling the influence of transitional elements in the manganite framework for high-performance supercapacitor

Super-capacitor is a well-competing energy storage system that involves fast-charging capability, a long-life cycle, stability, and good retention. Here, we examine solution combustion-derived AMn₂O₄ (A = Ni, Cu, Co, Zn) nanoparticles as a good supercapacitor electrode material. The electrochemical performance in a 2 M aqueous KOH electrolyte was investigated to find out the best working electrode with excellent activity. Out of all possibilities tested, NiMn₂O₄ delivered the utmost specific capacitance of 448.82 F g⁻¹ at 50 mVs⁻¹_. galvanostatic charge–discharge studies also confirmed that NiMn₂O₄ had a higher specific capacitance of 598.61 F g⁻¹ at 0.5 A g⁻¹ with energy and power density of 182.31 Wh/kg and 0.20 kW/kg, respectively. Furthermore, NiMn₂O₄ after 5000 cycles showed excellent long-term cyclic stability, maintaining an impressive retention capability of 96.68%. The results demonstrated that NiMn₂O₄ electrode had good stability and electrochemical reversibility, as well as specific capacity dependent on the type of transitional metal oxides.