Biomass derived activated carbon infused Sr doped ZnO nanoneedles for pseudocapattery applications

Strontium doped zinc oxide infused with activated carbon nanocomposites were synthesized via chemical precipitation method and utilized for energy storage applications. Crystal structure, surface morphology, binding energy and surface area were studied using X-Ray diffraction, Scanning and Transmission Electron Microscopy, X-ray Photoelectron Spectroscopy, Brunauer-Emmet-Teller Analysis, Fourier Transform Infrared spectroscopy and Raman spectroscopy. Cyclic voltammetry and chronopotentiometry analysis attributed to the pseudocapacitive nature of the synthesized nanocomposites which are confirmed further by the diffusive and capacitive contribution to the specific capacitance and the Dunn plot. The nanocomposites with 2 % activated carbon in the crystal structure showed higher Specific capacitance of 792.42 F/g at a current density of 1 A/g and charge transfer resistance of 3.81 Ω with an energy and power density of 39.62 Wh/Kg and 514.28 W/Kg respectively with a cyclic stability retention of 97.9 % over 2000 cycles for the three-electrode configuration. The SZOA-2 % nanocomposites showed a specific capacitance of 86.95 F/g at 1 A/g with an energy density of 18.56 Wh/Kg and a power density of 619.69 W/kg for the two-electrode system showing the nature of the nanocomposites as a highly reliable hybrid supercapacitor. • SZOA nanocomposites were biosynthesized using P.nigrum seed extract via chemical precipitation method for energy storage applications. • SZOA nanocomposites formed were of needle like crystal shaped and utilized for electrochemical studies. • SZOA-2 % nanocomposites showed specific capacitance of 792.42 F/g with an energy density of 39.62 Wh/Kg for three-electrode system. • Similarly, SZOA-2 % nanocomposites showed specific capacitance of 86.95 F/g with an energy density of 18.56 Wh/Kg for two-electrode system. • SZOA-2 % nanocomposites retain a cyclic stability of 97.9 % of the capacitance over 2000 cycles.