Effect of Fe doping on the structural and electrochemical performance of Zn@CuO nanostructures for energy storage device

Abstract

The demand for supercapacitors increases as the technology grows due to their high-power density and long cycle life. This work presents a hydrothermal approach to synthesize iron-doped zinc copper oxide (Fe@ZnCuO). The XRD technique was used to determine phase identification and lattice parameters. The maximum capacity achieved with Fe@ZnCuO was 938C/g (1563 F/g) at a current density of 1.5 A/g. The asymmetric device Fe@ZnCuO//AC was developed with activated carbon as the negative and Fe@ZnCuO as the positive electrode. At 1.5 A/g current, Fe@ZnCuO//AC had a capacity of 144C/g (90 F/g). Energy and power density achieved with Fe@ZnCuO//AC at 1.5 A/g current were 44.12 Wh kg−1 and 850 W kg−1, respectively. The durability test was also performed with Fe@ZnCuO//AC hybrid device, measuring up to 15,000 consecutive charging/discharging cycles. After completing 15,000 cycles, Fe@ZnCuO can retain 98% of its initial capacity. These findings imply that Fe@ZnCuO can be the best electrode material for asymmetric supercapacitors applications in the future.