Hollow reduced graphene oxide-NiCo hydroxide nanowall hydrid structure for high-performance supercapacitor

We fabricated the core shell structures of Polystyrene (PS)/negatively and positively charged reduced graphene oxide (rGO) through Layer-By-Layer (LBL) method. And the very rough Nickel-Cobalt hydroxide nanowall was attached on the rGO surface by hydrothermal synthesis. After that we successfully removed core material PS using toluene. Finally, hollow rGO@NiCo hydroxide nanowall was achieved. When evaluated as an electrode material for supercapacitor devices, the high capacitances of 518.4, 425.25, 314.55, 269.55, 242.28 and 203.4 F g^-1 at the different current densities of 0.5, 1, 2, 4, 6 and 8 A g^-1 respectively. They also represented superior cycling stability of 97.6% retention after cycling testing up to 3,000 times at 2 A g^-1. Thus, the hollow rGO@NiCo hydroxide nanowall exhibited a prominent improvement in electrochemical performance.