In-situ pyrolysis of MnO2/PVDF composites on carbon cloths and their enhanced electrochemical performances

Abstract With the increasing demand for preparing energy storage devices, composites containing metal oxides, have been widely developed and used as supercapacitors. However, the electrochemical performances of such materials are unable to be satisfied owing to the inherent poor conductivity. Herein, we employ “in-situ pyrolysis” approach to fabricate composite electrode materials without binding agents, which are obtained by the direct calcination of the mixture MnO2 and poly(vinylidene difluoride) coated on carbon cloths, generating a family of binder-free electrode materials BE-X. For comparison, another family of electrode materials CE-X have been obtained through the conventional method. Naturally, two different families of electrode materials are prepared and exhibit different electrochemical performances. In general, the performances of electrode materials prepared by an “in-situ pyrolysis” approach are better than those of electrode materials via the conventional method, indicating the enhanced adhesion between electrode materials and current collectors could be benefit for the electrochemical process. Among all prepared electrode materials, BE-7 exhibits the best performance (5.44 F·cm-2 at 5 mV·s-1) as well as a good rate stability. Furthermore, a flexible symmetric supercapacitor device based on BE-7 is also prepared, and exhibits an areal capacitance of 100.50 mF·cm-2.