Exceptional supercapacitive performance of bicontinuous carbon/MnO2 composite electrodes

A new type of porous carbon/MnO₂ composites, having bicontinuous structures, i.e., continuous channels and carbon skeletons, was prepared using a phase separation method, followed by a carbonization procedure and a subsequent redox reaction. In this work, such composite electrodes show a high specific capacitance of ca. 260?F?g^?1 at 0.5?A?g^?1 in 1?M Na₂SO₄ aqueous solution, a superior cycling stability (~80% retention after 2000 cycles) and a distinctive high-rate performance. Especially, unique bicontinuous structures endow such composites with a great specific capacitance of the constituent MnO₂ (~1100?F?g^?1), very close to the theoretical value. These excellent electrochemical behaviors may render this material a promising candidate as high-performance electrodes in supercapacitors. Therefore, our findings suggest that the strategy for constructing bicontinuous hybrid electrodes represents an exciting direction for designing next-generation supercapacitors.