Flexible Manganese Oxide Electrode Fabricated with Heat-Treated Buckypaper for Supercapacitor

With the emergence of new technologies, wearable and portable devices become essential tools for various applications, which are flexibly designed. In this situation, flexible supercapacitors with fast charge and discharge cycles are needed as their power source. This study introduces the flexible pseudocapacitor electrode fabricated by electrodeposition of manganese oxide (MnO₂) onto heat-treated hydrophilic buckypaper (BP) molded on polydimethylsiloxane (PDMS). Here, the heat treatment of BP that is optimized by a proper adoption of thermogravimetric analysis is performed to enhance the electrodeposition efficiency of MnO₂. Then, proper hydrophilicity of the heat-treated BP (H-BP) and successful preparation of MnO₂/H-BP@PDMS electrode is well confirmed by electrochemical, spectroscopical, and optical measurements. In their evaluations, it is found that heat treatment of BP is more important factor than electrodeposition time to improve the electrodeposition efficiency of MnO₂ under the same aqueous electrolyte. With that, such optimally prepared MnO₂/H-BP@PDMS electrode shows a high electrical double layer and excellent specific capacitance of 1.31 F/cm² at 1 mA/cm², which are better results than those of other electrodes.