Electrochemical Capacitances of a Nanowire-Structured MnO₂in Polyacrylate-Based Gel Electrolytes

Nanowire-structured MnO 2 was synthesized by a sonochemical method and its electrochemical capacitances were investigated in three kinds of electrolytes: liquid-type KCl solution, potassium polyacrylate (PAAK), and potassium polyacrylate- co -polyacrylamide (PAAK-PAAM) gel polymer electrolytes (GPEs). The prepared MnO 2 with a nanowire structure had a high specific surface area and narrow pore distribution, which was very useful for gel-type electrolyte in supercapacitor applications. The specific capacitance of nanowire-structured MnO 2 with PAAK electrolyte exceeded 484 F g −1 at the conventional loading weight of MnO 2 (1.02 mg cm −2 ) in the electrode. The nanowire-structured MnO 2 with PAAK electrolytes was a very promising electrode material for high-performance supercapacitors.