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

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.