Flower-like polyaniline–NiO structures: a high specific capacity supercapacitor electrode material with remarkable cycling stability

In this study, we report a binder-free in situ approach to synthesize a polyaniline–NiO composite on a nickel foam as a supercapacitor electrode. A high specific capacitance of 2565 F g−1 at a current density of 1 A g−1 is achieved and it remains at 70% when increasing the current density by 10 times. Flower-like nanostructures are identified and offer a structural benefit for high levels of redox. Furthermore, this electrode also exhibits excellent cycling stability with a high retention of 100% for almost 5000 cycles.