Polypyrrole and Manganese Oxide Composite Materials with High Working Voltage and Excellent Cycling Stability

In an aqueous mixture of manganese acetate, ammonium acetate and pyrrole, PPy and MnO 2 composite materials (PPy‐MnO 2 ) are synthesized by i‐t technology at 0.9 V vs . SCE. The influences of manganese acetate to pyrrole in the electro‐codeposition solution on morphologies and charge storage properties of the composite are discussed. PPy‐MnO 2 composite materials as the electrode material exhibit a wide charge‐storage potential window of 1.2 V (between −0.3 and 0.9 V vs . SCE) and a high specific capacitance of 345.54 F g −1 at 2 mA cm −2 . A symmetric flexible supercapacitor (PPy‐MnO 2 //PPy‐MnO 2 ) is assembled by using PPy‐MnO 2 composite electrodes. PPy‐MnO 2 //PPy‐MnO 2 model supercapacitor displays almost 100% capacitance retention on the different bending angles. The energy density of 37.63 Wh kg −1 at the power density of 830 W kg −1 and an immense cyclic charge‐discharge stability, the specific capacitance is lost less than 3% after the 10,000 galvanostatic charge‐discharge cycles. The successful synthesis of high performance composite electrodes using electro‐codeposition method could open up new opportunities for high energy density supercapacitors.