A thiophene-sulfur doping porous organic Polymer/reduced graphene oxide composite for high-performance supercapacitor electrode

Abstract

Porous organic polymers (POPs) are a type of promising materials which can be used in energy storage devices. In this study, we synthesized a novel thiophene-sulfur doping POPTAB-TPDA through Schiff-base condensation reaction between 1,3,5-triaminobenzene (TAB) and 2,5-thiphenedialdehyde (TPDA) at ambient temperature and pressure. With the reduced graphene oxide (rGO) as a template, thiophene-sulfur doping POPTAB-TPDA-rGO composite was obtained by in-situ synthesis under the same condition. As supercapacitor active electrode material, the stable value of specific capacitance of the POPTAB-TPDA-rGO composite (232.4 F g−1) is higher than that of pristine POPTAB-TPDA (193.5 F g−1) at a current density of 0.5 A g−1. The assembled asymmetric supercapacitor utilizing POPTAB-TPDA-rGO composite as positive material has an energy density of 38.7 W h kg−1 with the power density of 1619.2 W kg−1, displaying a better result than POPTAB-TPDA-based device. Furthermore, the POPTAB-TPDA-rGO-based supercapacitor exhibits an excellent cycle duration, with 81.7 % retention of its highest capacitance after 7000 cycles. This superior electrochemical performance of the composite could be attributed to three aspects: the reversible redox reaction processes of thiophene-sulfur units, the porous structure of POPTAB-TPDA facilitating ion transmission, and the good electron conductivity of rGO template.