The capacitance characteristics of polybenzidine-based donor-acceptor conductive conjugated polymer electrodes enhanced by structural modification and carbon cloth loading

Through a concise and scalable method, polybenzidine based donor-acceptor conductive and conjugated polymers with relatively narrow optical and electrochemical band gaps were successfully synthesized. Electrodes modified with these conjugated polymers and their carbon cloth (CC)-supported flexible electrodes all had excellent capacitance characteristics. The introduction of substituent to donor unit could improve its capacitance properties. All samples had high specific discharge capacitance (>344.8 F.g(-1)) and almost no capacity decay was found after 2500 cycles. The first discharge specific capacitance of P2 with methyl substitution was 655.6 F.g(-1), and its energy density was 52.0 Wh.kg(-1) with a power density of 1627.83 Wh.kg(-1), which were all belong to higher values. Because of methyl group could increase the electron affinity, its LUMO value was decreased. Although the specific capacitance of P2 was large, the specific capacitance were further significantly increased after the CC supporting with an increased power density of P2@CC, showing their great application potential in flexible devices.

Automated summary

By using a concise and scalable method, polybenzidine based donor-acceptor conductive and conjugated polymers with narrow optical and electrochemical band gaps were synthesized successfully. The electrodes modified with these conjugated polymers and their carbon cloth (CC)-supported flexible electrodes demonstrated excellent capacitance characteristics. Introducing substituents to the donor unit improved its capacitance properties. All samples exhibited high specific discharge capacitance (>344.8 F.g(-1)) and minimal capacity decay after 2500 cycles. The introduction of methyl substitution in P2 resulted in a first discharge specific capacitance of 655.6 F.g(-1), an energy density of 52.0 Wh.kg(-1), and a power density of 1627.83 Wh.kg(-1), which were all relatively high. Despite the already large specific capacitance of P2, further significant increases in specific capacitance were observed after CC supporting with an increased power density of P2@CC, indicating great potential for flexible device applications.