PEDOT:PSS coated CuO nanowire arrays grown on Cu foam for high-performance supercapacitor electrodes

Supercapacitors based on transition metals oxides (TMOs) have recently attracted immerse attentions in lightweight and durable energy-storage devices. Noted that poor conductivity is a major problem for the TMOs active materials, such as CuO. Herein, vertically-aligned CuO nanowire arrays@poly (3,4 ethylenedioxythiopene)/poly (styrene-4-sulfonate) (CuO NWAs@PEDOT:PSS) were synthesized in situ on Cu foam through a facile wet-chemical approach combined with immersion method. The PEDOT:PSS layer provides the electron transport paths to maximize the charge storage (the capacitance) and contributes to the additional pseudocapacitance, as well as alleviates the exfoliation and dissolution of CuO NWAs during the charge storage process. The prepared CuO NWAs@PEDOT:PSS composite electrodes exhibit a higher areal capacitance (907.5 mF/cm² at 3 mA/cm²), which is about 2.5 times of the pure CuO NWAs electrode, together with a longer cycle life span. The enhanced electrochemical performances originate from the unique structure design of double conductive layer with the top conductive polymer and the bottom metal foam for CuO NWAs active material. This effective approach is of great significance for portable energy-storage devices based on TMO materials.