Facile Synthesis of Graphite/PEDOT/MnO₂ Composites on Commercial Supercapacitor Separator Membranes as Flexible and High-Performance Supercapacitor Electrodes

Abstract

A facile and low-cost method is presented to synthesize graphite/PEDOT/MnO₂ composites with controlled network structures on commercial supercapacitor separator (CSS) membranes for high-performance supercapacitors, in which pencil lead and a cellulose-based commercial supercapacitor separator membrane were applied as the graphite source and the flexible substrate, respectively. The dependence of PEDOT and MnO₂ loading on the structural formation, the electrochemical performance of the hybrid electrode, and the formation mechanism of MnO₂ nanowires are systematically investigated. The optimized electrode possesses a high areal capacitance of 316.4 mF/cm² at a scan rate of 10 mV/s and specific capacitance of 195.7 F/g at 0.5 A/g. The asymmetric supercapacitor device assembled using optimized CSS/Graphite/PEDOT/MnO₂ electrode and activated carbon electrode exhibits a high energy density of 31.4 Wh/kg at a power density of 90 W/kg and maintains 1 Wh/kg at 4500 W/kg. After 2000 cycles, the device retains 81.1% of initial specific capacitance, and can drive a mini DC-motor for ca. 10 s. The enhanced capability of the CSS-based graphite/PEDOT/MnO₂ network electrode has high potential for low-cost, high-performance, and flexible supercapacitors