CuS/C@NiMnCe-layered double hydroxide with core-shell rods array structure as the cathode for high performance supercapacitors.

The selection of highly efficient materials and the construction of advantageous structures are essential for realizing high-performance electrode materials. In this paper, electrode material CuS/C@NiMnCe-LDH/CF with excellent morphology and high performance has been successfully designed and prepared by simple hydrothermal and calcination techniques. First, ZIF-67 is loaded on the outer layer of CuS rods to obtain core-shell structured CuS@ZIF-67 rods, whose ZIF-67 MOF shell is carbonized to obtain CuS@C rods. Then, NiMnCe-LDH are epitaxially loaded on the outer layer of CuS@C to obtain CuS/C@NiMnCe-LDH rods. At a current density of 2 mA cm, CuS/C@NiMnCe-LDH/CF exhibits an area capacitance of 5176.4 mF cm. The mass capacitance and the energy density of the CuS/C@NiMnCe-LDH/CF//AC asymmetric supercapacitor (ASC) reach 150.82F g at a sweep rate of 0.8 A/g and 53.62 Wh kg at a power density of 639.99 W kg, respectively. Meanwhile, after 8000 electrochemical cycles, the specific capacitance of CuS/C@NiMnCe-LDH/CF//AC still has a retention rate of 86.32 %, which proves its excellent cycling stability. These results demonstrate a new strategy for the preparation of novel core-shell structured CuS/C@NiMnCe-LDH/CF nanocomposite material for electrode materials of energy storage devices with superb performance.