A Simple Route to\nFabricate Ultralong and Uniform\nPolypyrrole Nanowires with High Electrochemical Capacitance for Supercapacitor\nElectrodes

Abstract

This work demonstrated a straightforward strategy to\nfabricate\nultralong interconnected polypyrrole (PPy-GS) nanowires with a gemini\nsurfactant (GS) as a soft template and dopant. Pure PPy particles\nand a PPy nanowire doped with CTAB (PPy-CTAB) were prepared for comparison.\nThe results showed that the electrochemical performances, conductivity,\nand morphology of PPy-GS could be significantly changed by changing\nthe concentration of GS in the aqueous phase owing to the different\nself-assembly behaviors. When the molar ratio of pyrrole, APS, and\nGS was 1:1:0.4, an interconnected ultralong and uniform PPy-GS nanowire\nwith the largest surface area, the smallest average pore size, the\nlowest contact angle, and the highest conductivity can be obtained,\nresulting in the formation of effective electrolyte transport channels\nand faster electron transport pathways. Compared with pure PPy particles\nand the PPy-CTAB nanowire, the incorporation of GS significantly enhanced\nthe conductivity and specific capacitance of PPy-GS-40%. The conductivity\nof PPy-GS-40% was up to 13.54 S/cm compared with 1.17 S/cm for PPy\nparticles and 3.84 S/cm for the PPy-CTAB nanowire. Also, the highest\nspecific capacitance of PPy-GS reached up to 556 F/g at 1 A/g compared\nwith 233 F/g for PPy particles and 397 F/g for the PPy-CTAB nanowire.\nA total of 85.4% of the initial capacitance was retained even after\n2000 cycles at 1.0 A/g. The energy density and power density of the\nPPy-GS-40% symmetrical supercapacitor were 49.4 Wh/kg and 400 W/kg,\nrespectively. The good electrochemical properties of the PPy-GS electrode\nsuggest a tremendous potential in the high-performance electrode not\nonly for supercapacitors but extensively for various energy storage\napplications.