Peanut shell-derived activated carbon incorporated with ZnCo2O4 in alkaline solution for high performance asymmetric supercapacitors.

Supercapacitors have attracted a lot of interest in energy storage technology because of their affordability, large capacity, high energy efficiency, and exceptional stability. In this work, zinc cobaltite (ZnCo2O4) was combined with a biomass-derived carbon material derived from peanut shells to create a ZnCo2O4/PAC nanocomposite using an easy and affordable hydrothermal process. The combination of ZnCo2O4 and Powder Activated Carbon (PAC) forms a good conductive network that provides extra redox-active sites and facilitates electron transit. When compared to pristine ZnCo2O4 (530 F g-1), the designed electrode had the most effective charge storage behavior in basic electrolyte, attaining a capacitance of 781 F g-1 at 1 A g-1. Besides, an asymmetric supercapacitor (ZnCo2O4/PAC//AC) device presented a notable capacitance of 160 F g-1 with an excellent energy density of 50 Wh kg-1. The device retained 92% of its initial capacitance retention after 6000 cycles, showing its good cycling reliability. The remarkable performance is attributed to ZnCo2O4's improved charge transfer, and PAC's high surface area, which overall improved the electronic conductivity and ion diffusion. These outcomes reveal that the ZnCo2O4/PAC composite provides directions for the development of future high-performance supercapacitors.