Very High Pressure Synthesis – An Effective Way to Enhance the Capacitance and Rate Performance of Polypyrrole Films

摘要

Very high pressure (VHP) was employed to synthesize polypyrrole (Ppy) films. We observed highspecific capacitance, excellent rate performance, and report the specific energy for Ppy films insupercapacitor electrodes. The Ppy film electrode synthesized under the VHP of 500 MPa exhibitedhigh specific capacitance (526 F/g) at a scan rate of 2 mV/s. This specific capacitance was about twotimes higher than that was observed with electrodes prepared under ambient pressure in an acidicelectrolyte. With an extremely high current density of 8 A/g, a specific energy of 109.8 Wh/kg wasobtained for a Ppy film electrode synthesized under the VHP of 500 MPa. In addition, Ppy filmelectrodes prepared under the VHP of 500 MPa demonstrated cycling stability after 1000 charge- discharge cycles (potential window of -0.2 ~ 0.8 V, current density of 8 A/g) with 74.6 % retention ofthe initial capacitance. The stability of VHP-synthesized PPy film electrodes is superior to that of Ppyfilm electrodes prepared under ambient conditions.