Fabrication of coin cell supercapattery device using morphology-controlled nickel cobaltite nanostructures as active material

A supercapattery based coin cell is fabricated to be used as an efficient energy storage device. Nickel cobaltite (NiCo2O4) nanostructures are synthesized by facile hydrothermal method at 180 °C for different reaction time such as 6 h, 9 h, 12 h (NCO6, NCO9 and NCO12). These nanostructures possess the spinel cubic structure with hexagonal morphology. The prepared electrodes are subjected to electrochemical performance analysis with standard three cell and two cell configurations. Among the samples, NCO6 shows higher specific capacity of 1720C g−1 as confirmed by both Cyclic Voltammetry (CV) and Galvanostatic Charge-Discharge (GCD) measurements. The performance of electrode reveals a capacity retention of 99 % with Coulombic efficiency of 94 % in 10,000 charge-discharge cycles. Quantitative percentage of both capacitive and diffusive contributions of the electrode material are estimated using the power law. The coin cell is fabricated using nickel cobaltite//activated carbon (NCO6//AC) using aqueous electrolyte of potassium hydroxide (KOH) in 2 M concentration at a potential of 1.5 V with a specific power density of 375 W kg−1 and superior specific energy density of 43.54 Wh kg−1 at 0.5 A g−1. Furthermore, the device performance is tested with a LED as the load to assess its real-life applications.