PPy coated nanoflower like CuCo2O4 based on in situ growth of nanoporous copper for high-performance supercapacitor electrodes

General CuCo2O4 electrodes suffer a very low reversible capacity and poor cycling stability because of easily fading phenomena and volume change during cycling. To optimize the electrode, a facile method is conducted to fabricate a novel electrode of Cu@CuCo2O4@polypyrrole nanoflowers. Due to larger specific surface area and more electrochemical reactive areas of CuCo2O4@polypyrrole nanoflowers, the pseudocapacitance of the in situ grown CuCo2O4@polypyrrole (912 F g(-1) at 2 A g(-1)) is much higher than the pristine CuCo2O4 (618 F g(-1) at 2 A g(-1)). Remarkably, the CuCo2O4@polypyrrole (cathode) and active carbon (anode) are used to assemble an asymmetric supercapacitor, which exhibits a relatively high energy density of 90 Wh kg(-1) at a power density of 2519 W kg(-1) and 35 Wh kg(-1) at a high-power density of 9109 W kg(-1), and excellent cycling stability (about 90.4% capacitance retention over 10 000 cycles). The prominent performance of CuCo2O4@polypyrrole makes it as a potential electrode for supercapacitor.

Automated summary

A novel electrode of Cu@CuCo2O4@polypyrrole nanoflowers is fabricated to improve the performance of CuCo2O4 electrodes. The in situ grown CuCo2O4@polypyrrole shows a much higher pseudocapacitance compared to pristine CuCo2O4. Furthermore, an asymmetric supercapacitor assembled with CuCo2O4@polypyrrole as cathode and active carbon as anode exhibits excellent performance in terms of energy density and cycling stability.