Increased Energy\nDensity with Conjugated Polymer-Based\nComposite Electrode without Power Density Sacrifice

The joint of capacitance and diffusion contribution in\nelectrode\nmaterials of supercapacitors is effective to achieve high energy density\nwithout power density sacrifice. Therefore, a series of donor–acceptor\ntype conductive polymers with benzidine as the donor and other monomers\nhaving different aromaticity as the acceptor have been designed and\nsynthesized. In this study, after the binary flexible electrode from\nthe thiophene ring-containing polymer on carbon cloth was modified\nwith the Prussian blue analogue CoFePBA, a flexible ternary composite\nelectrode with integrated capacitance and diffusion capabilities was\nprepared. Its specific capacitance was up to 1135.72 F/g at 0.5 A/g\nwith a retention ratio of 98.45% after 10,000 cycles. Its electrochemical\nperformance remained basically unchanged after 1000 times of bending.\nWhen the energy density of a two-electrode supercapacitor device assembled\nwith the as-made electrode reached up to 13.8 W h/kg, it is at a high\npower density of 745.9 W/kg, and it shows 6.7 W h/kg even at maximum\npower density of 5010.1 W/kg.