All-solid-state wire-shaped asymmetric supercapacitor based on binder-free CuO nanowires on copper wire and PPy on carbon fiber electrodes

A wire-shaped asymmetric supercapacitor based on CuO and polypyrrole (PPy) is developed in this work. The fiber-shaped positive electrode composed of CuO nanowires (CuO NWs) on Cu wire (Cu wire/CuO NWs) is successfully prepared via anodization of copper wire followed by thermal treatment. Meanwhile, conductive polymer PPy is grown on carbon fiber bundle (CF/PPy) by electrodeposition as a negative electrode. Subsequently, an all-solid-state wire-shaped asymmetric supercapacitor is assembled with Cu wire/CuO NWs, CF/PPy and PVA-KOH gel electrolyte. Benefiting from the efficient pseudocapacitive properties of the binder-free positive electrode with CuO nanowires directly grown on the copper wire surface and the negative electrode with PPy tightly covered on the carbon fibers, the all-solid-state wire-shaped asymmetric supercapacitor assembled exhibits a high energy density (9.31 mu Wh cm-2) and specific capacitance (39.67 mF cm-2, 24.91 mF cm-1). Moreover, this device also shows an excellent stability of electrochemical performance at different bending conditions, demonstrating its potential to serve as a flexible power source for portable/wearable electronics.

Automated summary

An asymmetric supercapacitor utilizing CuO and PPy was developed, showing high energy density and specific capacitance. The positive electrode consists of CuO nanowires, while the negative electrode is composed of PPy. Assembled with a gel electrolyte, it exhibits excellent stability and potential as a flexible power source for portable electronics.