Search

Hybrid materials PPy/Ni–Co LDH based on polypyrrole nanotubes and Ni–Co LDH from ZIF-67 templates were employed as electrode materials for supercapacitors, where Ni–Co LDH possesses a hollow structure. With the help of appreciative composition and a hollow structure, the optimum PPy/Ni–Co LDH shows an excellent performance with high specific capacitances (4.4 C cm−2 at 1 mA cm−2 and 3.35 C cm−2 at 20 mA cm−2). [ABSTRACT FROM AUTHOR]

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 MnO 2 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. Two family of electrodes prepared by different methods exhibit varied performances, where the performances of binder-free electrodes prepared by the in-situ pyrolysis approach are better than those of electrodes by the conventional methods. Image 1 • An efficient binder-free electrode has been prepared simply through "in-situ pyrolysis" approach. • The electrodes prepared by different methods result in different performances. • The performance of binder-free electrodes are better than those of electrodes prepared by conventional electrodes. • A flexible symmetric supercapacitor device exhibits an areal capacitance of 100.5 mF cm−2. [ABSTRACT FROM AUTHOR]