Study On The Wire-Shaped Flexible Asymmetric Supercapacitor Based On Manganese/Vanadium Metal Oxides

Recently, with the rapid development of flexible, lightweight, folding and wearable electronic components, a lot of incredible intelligence products with good performance have been achieved. As a new concept of photoelectric devices, wire-shaped fiber devices not only make a breakthrough in improving mechanical flexibility of device, but show perfect bending performance. These advantages make them easy to be woven into any shape and implanted in any fabric, which pave the way for the design of wearable electronic equipment. As a new member of the energy storage devices, wire-shaped supercapacitor has series advantages, such as small, light, flexible and wearable.In this article, we use flexible, conductive carbon fiber as template, and the diameter of the carbon fiber is about several microns, which provides favorable conditions for fabricating components with flexibility, miniaturization and lightweight. Our positive electrode is PPy-Mn O2-carbon fiber composite, and Mn O2 is highly suitable for fabricating supercapacitors due to its high theoretical capacitance, but shows poor electrical conductivity and easy to corrosion. To improve the conductivity of Mn O2, we wrapped a layer of high conductivity PPy at the outer surface of Mn O2 nanostructure. Negative electrode is PANI-V2O5-carbon fiber, and the pure V2O5 obtained by electrodeposition forms large particles and these particles easily pile up. While V2O5 and PANI coated on carbon fiber at the same time, so they can generate a good nanostructures on the carbon fiber, and these nanostructures provide channels for ions and electrons to transfer. Moreover, the difference of work function between Mn O2 and V2O5 is as large as 2.45 e V, which can improve the operation potential of device.Finally, we fabricated a wire-shaped flexible asymmetric supercapacitor successfully by a simple electrochemical deposition method. The wire-shaped flexible asymmetric supercapacitor showed a good capacitive performance of 0.613 F/cm2, as well as under severe bending states, which demonstrated a good flexibility. In addition, the device also kept stability after 5000 cycles.