One-pot synthesis of hybrid-ternary nickel-oxide decorated polypyrrole/activated carbon nanocomposite as cathode for record-high long life asymmetric supercapattery

Abstract

Biomass-derived electrode materials, despite their low cost and sustainability, exhibit poor stability, energy density, and cyclic stability, thereby being unsuitable for high-performance supercapacitor applications. To overcome these limitations, we report a one-pot solvothermal synthesis of hybrid ternary nickel-oxide decorated polypyrrole/activated carbon nanocomposite (NPC) for high-performance asymmetric supercapattery applications, wherein NiO and AC are derived from low cost and abundantly available Cactaceae biomass. Detailed morphological studies reveal NiO microspheres decorated within the nanowire-like polypyrrole and carbon nanosheets in the NPC nanocomposite. The optimized NPC electrode delivers 833.06 Fg-1 (416.53 Cg-1) of half-cell specific capacitance of at 1 Ag-1. An asymmetric supercapattery (ASB) device assembled with the NPC and AC as a positive and negative electrode, respectively shows 361.4 Fg-1 (180.7 Cg-1) of cell-specific capacitance at 1 Ag-1 with 98.3 Wh kg−1 of specific energy at 9330.57 Wkg-1 of specific power at 1.4 V and record-high 100% capacitance retention even after 12,000 cycles. This outstanding performance is attributed to the synergetic features of rapid electrolyte-ion diffusion because of the small energy difference between the ions in the NiO, high conductivity of CP and the porous nature with a high surface area of the AC. Thus, the bioorganic framework of NiO nanomaterials and biomass-derived carbon materials has demonstrated a novel route for improving the NPC composite's electrochemical energy storage capability.