PPy coated nanoflower like CuCo 2 O 4 based on in situ growth of nanoporous copper for high-performance supercapacitor electrodes.

General CuCo 2 O 4 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@CuCo 2 O 4 @polypyrrole nanoflowers. Due to larger specific surface area and more electrochemical reactive areas of CuCo 2 O 4 @polypyrrole nanoflowers, the pseudocapacitance of the in situ grown CuCo 2 O 4 @polypyrrole (912 F g -1 at 2 A g -1 ) is much higher than the pristine CuCo 2 O 4 (618 F g -1 at 2 A g -1 ). Remarkably, the CuCo 2 O 4 @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 CuCo 2 O 4 @polypyrrole makes it as a potential electrode for supercapacitor.