Flexible polypyrrole/cobalt sulfide/bacterial cellulose composite membranes for supercapacitor application

- PPy/CoS/BC composites were prepared by stepwise loading of PPy and CoS on bacterial cellulose (BC) membranes.
- Electrochemical performances of composites as supercapacitor electrodes were investigated.
- The introduction of CoS remarkably improved the cycling stability of BC-based electrodes.

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.