Preparation by Co metal-organic framework template and capacitive properties of NiCo-layered double hydroxide/nickel foam composites

Using a two-step method, a Co metal-organic framework (Co-MOF) nanosheet array was grown in situ on nickel foam (NF), and then Co-MOF nanosheets were etched with different concentrations of Ni2+ ion solution to obtain NiCo layered double hydroxide (NiCo-LDH). NiCo-LDH/NF inherits the Co-MOF nano-sheet structure to form a primary nano-sheet array and a secondary nano-sheet fold on the surface of the primary nano-sheet. NiCo-LDH/NF obtained by etching in 2 mmol Ni (NO3)(2)center dot 6H(2)O solution showed a small number of thin and folded secondary nano-sheets grown on the primary nano-sheet array,exhibited a high capacitance and high rate performance,had a specific capacitance of 7764.5 and 6098.2 mF.cm(-2) at a current density of 5 and 20 mA.cm(-2),and capacitance retention rate of 78.5%.After 5000 cycles at a current density of 20 A.g(-1),the capacitance retention rate was 85.9%.The hybrid capacitor assembled by NiCo-LDH/NF and active carbon achieved an maximum energy density of 38.9 Wh.kg(-1) and a maximum power density of 8000.0 W.kg(-1).