Au-assisted Polymerization of Conductive Poly(N-phenylglycine) as High-performance Positive Electrodes for Asymmetric Supercapacitors.

Herein, a novel conductive poly(N-phenylglycine) (PNPG) polymer was successfully prepared by in situ electrochemical polymerization method (+0.75 V vs. Ag/AgCl) for 10 min, supported on flexible stainless-steel plate coated with a thin Au film (Au/SS), to serve as binder-free pseudocapacitive PNPG/Au/SS electrodes for energy storage devices. Compared to the electrode without Au coating, PNPG/Au/SS electrode exhibited better electrochemical performance with larger specific capacitance (495 F g-1 at a current density of 2 A g-1), higher rate performance and lower resistance, which are good indications to act as a positive electrode for asymmetric supercapacitor devices. Combined with activated carbon (AC) as a negative electrode, a asymmetric supercapacitor device was constructed and assessed. It displayed a specific capacitance of 38 F g-1 at a current density of 0.5 A g-1 and an energy density of 5.3 Wh kg-1 at a power density of 250 W kg-1. Experimentally, two asymmetric supercapacitor devices were connected in series to power a home-made windmill continuously for 8 s, revealing the high potential of this novel conductive polymer materials for energy storage application.