High performance hybrid supercapacitor based on hierarchical MOF derived CoFe₂O₄ and NiMn₂O₄ composite for efficient energy storage

We have synthesized the hierarchical FeCo-MIL-88 (FC-MOF) derived CoFe₂O₄ and NiMn₂O₄ (CFO@NMO) composite using a hydrothermal route. The combination and formation process were presented. The prepared composite of CFO@NMO is studied using XRD, XPS, FESEM with EDS, HRTEM, and nitrogen adsorption and desorption isotherm. The formation of composite with CoFe₂O₄ (CFO) and NiMn₂O₄ (NMO) may effectively boost the conductivity thereby enhance the performance of electrochemical activity. Benefitting from the formation of composite, the hybrid CFO@NMO electrode achieved a high specific capacity (i.e., 353.6 mAh/g), 86.1 % retention in capacity after 5000 galvanostatic charging and discharging (GCD) cycles. To utilize the advantages of ultra-long cycling stability and high specific capacity, the aqueous electrolyte-based hybrid supercapacitor (HSC) device with AC//NF as a negative electrode and CFO@NMO//NF as a positive electrode was fabricated. The assembled HSC device provided a specific capacitance 312.8 F/g, 88.4 % retention in capacitance after 10,000 GCD cycles along with high energy density (90.3 Wh/kg) and power density (12.9 kW/kg). An easy and cost-effective preparation of CFO@NMO composite with outstanding supercapacitor performance demonstrates an excessive potential for utilization in the near future.