Electrodeposition of poly(3,4-ethylenedioxythiophene) coated manganese dioxide nanospheres for flexible asymmetric planar supercapacitor with superior energy density

Although planar asymmetric supercapacitors (ASCs) have attracted extensive attentions as prospective microscale energy storage devices, their practical applications are severely confined by the low energy density and inefficient patterning techniques. Herein, poly (3,4-ethylenedioxythiophene) (PEDOT) coated manganese dioxide (MnO2) nanospheres (MnO2@PEDOT) as cathode is firstly fabricated by electrodepositing. Benefitting from the synergistic effect of the nanocomposites, MnO2@PEDOT cathode displays a broad operating voltage from 0 to 1.0 V (vs Ag/AgCl), excellent areal specific capacitance (116.9 mF cm-2 at 0.1 mA cm-2) with outstanding rate capability and cyclic stability. To complement the wide potential of planar ASCs, urchin-like vanadium pentoxide (V2O5) is similarly fabricated as anode with superb electrochemical performance. As a result, the as-assembled V2O5//MnO2@PEDOT planar ASCs show superior characteristics including a stable operating voltage of 1.8 V, commendable energy density of 15.1 mu Wh cm-2 along with remarkable cycle performance (87.2% retention after 10 000 cycles), and distinguished integrated performance with commercial solar cells, which exceed majority of formerly reported analogous works. Therefore, this work will create new opportunities for high-performance pseudocapacitive planar ASCs to meet the power requirements in wearable and integrated systems.