Synthesis of NiCo-layered double hydroxide/multilayer graphene composite via the ozone oxidation combined microwave-assisted synthesis strategy

There is an ever-growing demand for developing environment-friendly and cost-effective approach to synthesize high-performance supercapacitor electrode materials. This work proposes a facile, rapid and environmentally-friendly strategy to prepare NiCo-layered double hydroxide/multilayer graphene composite (termed as NiCo-LDH/MLG) using methods of ozone oxidation and microwave-assisted synthesis. The NiCo-LDH/MLG possesses a distinctive 3D petal-like porous architecture, which endows a high specific capacitance of 1212.75 F·g−1 at the current density of 1 A·g−1 in a three-electrode system. Moreover, the NiCo-LDH/MLG exhibit excellent rate capability with 80.5% of the capacitance retained at 6 A·g−1 even after 3000 cycles. In addition, the symmetrical supercapacitor based on NiCo-LDH/MLG delivered a high energy density of 23.14 Wh·kg−1 at a power density of 1049 W·kg−1.