Organic Molecular Electrode with Ultrahigh Rate Capability for Supercapacitors

摘要

This work reports a feasible method to fabricate a novel organic molecule electrode, in which 3,4,9,10-perylenetetracarboxylic acid (PTCA) is immobilized on the surface of reduced graphene oxide (rGO(1)) by using a noncovalent strategy. In the three-electrode configuration, the specific capacitance for the PTCA/rGO(1) electrode is 422.7 F g(-1) at 10 mV s(-1). More importantly, it can retain 94.6% of the initial value at 100 mV s(-1). This ultrahigh rate capability could be put down to ultrafast protonation/deprotonation electrochemical reaction based on the four carboxyl groups in PTCA. To further explore the practical performance of electrode materials, an asymmetric supercapacitor (PANI/rGO(2)//PTCA/rGO(1)) is constructed by using PTCA/rGO(1) and PANI/rGO(2) as the negative and positive electrode, respectively. The device (PANI/rGO(2)//PTCA/rGO(1) ASC) reveals an outstanding energy storage capacity, in which the energy density reaches 14 W h kg(-1) along with a power density of 520 W kg(-1).