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The developments of flexible supercapacitors are of great importance to the growing demand of portable electronic products. In the present work, we have successfully prepared bacterial cellulose (BC) membranes coated by polypyrrole (PPy) and copper oxide (CuO) as flexible composite electrodes for supercapacitor applications. The highest electrical conductivity value of 7.4 S cm was achieved using copper acetate aqueous solution with concentration of 1 wt%. Electrochemical measurements proved that the supercapacitors using the PPy/CuO/BC electrodes had a specific capacitance of 601 F g with an energy density of 48.2 Wh kg and a power density of 85.8 W kg at a current density of 0.8 mA cm. The specific capacitance was kept at 385 F g after 300 cycles. The introduction of the CuO nanoparticles gave rise to the improved capacitance. [ABSTRACT FROM AUTHOR]

Polypyrrole (PPy) and copper sulfide (CuS) have been successfully deposited on bacterial cellulose (BC) membranes to prepare nanofibrous composite electrodes of PPy/CuS/BC for flexible supercapacitor applications. The introduction of CuS remarkably improves the specific capacitance and cycling stability of BC-based electrodes. The specific capacitance of the supercapacitors based on the PPy/CuS/BC electrodes can reach to about 580 F g −1 at a current density of 0.8 mA cm −2 and can retain about 73% of their initial value after 300 cycles, while the PPy/BC-based device could retain only 21.7% after 300 cycles. This work provides a promising approach to fabricate cost-effective and flexible nanofibrous composite membranes for high-performance supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) has attracted much attention due to its low-cost, high specific surface area and ample porosity. In this work, polypyrrole (PPy) and cobalt sulfide (CoS) have been deposited on BC membranes to prepare the nanofibrous composite electrodes of PPy/CoS/BC with excellent flexibility for supercapacitor application. The introduction of CoS remarkably improves the pseudocapacitance and electrochemical stability of PPy/BC-based electrodes. The specific capacitance of the PPy/CoS/BC-based supercapacitors can reach to about 614 F g −1 at a current density of 0.8 mA cm −2 (0.70 A g −1 ) with maintaining 62.4% of the original value after 300 cycles; while the PPy/BC-based device could retain only 21.7% after 300 cycles. The PPy/CoS/BC-based devices can exhibit an energy density of about 54.5 Wh kg −1 at a power density of 663 W kg −1 . This work provides a promising approach to fabricate cost-effective and flexible membranes which can be used as high-performance supercapacitor electrodes. [ABSTRACT FROM AUTHOR]