Bacterial cellulose composites (MXene@TOBC@PPy) for flexible supercapacitors with improved electrochemical performance

Bacterial cellulose (BC)/polypyrrole (PPy) nanofibrous composites have been extensively studied in supercapacitors owing to their large specific surface area and excellent tensile strength. However, the inferior cycling stability due to structural pulverization of PPy impedes their potential applications. Herein, nanofibrous composite membranes of MXene, PPy and oxidized BC (TOBC) were prepared for flexible supercapacitor electrodes. The C6 primary hydroxyl groups of BC nanofibers were oxidized into aldehyde or carboxyl groups. Due to the enhanced interaction of TOBC with PPy and MXene, the TOBC nanofibers were horizontally wrapped on the MXene nanosheets and PPy was homogeneously deposited on the TOBC nanofibers. The flexible solid-state supercapacitors fabricated with the MXene@TOBC@PPy (TMP) electrodes achieved an areal specific capacitance of 928.9 mF cm −2  at 0.7 mA cm −2  and a capacitance retention of 85.5% after 5000 cycles. Therefore, the TMP electrodes could be a promising electrode material for flexible supercapacitors.