Potentiostatic deposition of poly(3, 4-ethylenedioxythiophene) and manganese oxide on porous functionalised carbon fibers as an advanced electrode for asymmetric supercapacitor

A rational design of porous functionalised electrospun carbon fibers/poly(3,4-ethylenedioxythiophene)/manganese oxide (P-f-CNFs/PEDOT/MnO2) has been proposed as a positive electrode for asymmetric supercapacitors (ASC). The unique mesoporous structure of P-f-CNFs offers a large active surface area, which shortens the ion diffusion length into the inner pores, contributing to high specific capacitance and excellent cyclability. The presence of high electrical conductivity of PEDOT and high theoretical specific capacitance of MnO2 on P-f-CNFs show synergistic interaction between them, giving an outstanding supercapacitive performance. P-f-CNFs/PEDOT/MnO2 exhibits superior specific capacitance of 776.7 F/g compared with P-f-CNFs/PEDOT (595.4 F/g), P-f-CNFs/MnO2 (449.7 F/g) and P-f-CNFs (170.2 F/g) at a scan rate of 25 mV/s in 1 M KCl. ASC device was assembled using P-f-CNFs/PEDOT/MnO2 (positive) and PCNFs (negative) which offers wide potential window up to 1.6 V. Significantly, the ASC device can deliver specific capacitance of 1061 F/g, remarkable specific energy (60.5 Wh/kg), excellent cycling stability (104.6% capacity retention after 5000 cycles) and able to light up 25 commercial light emitting-diodes (LEDs). These promising results prove that P-f-CNFs/PEDOT/MnO2//PCNFs can be an ideal candidate for next generation supercapacitor electrode.