Ni-Co-Fe layered double hydroxide coated on Ti3C2 MXene for high-performance asymmetric supercapacitor

Highlights: • Core-shell NiCoFe-LDH/Ti3C2 MXene composite have been fabricated. • NiCoFe-LDH is coated on the surface of MXene via the surface functional group of MXene. • Provides a new idea for the synthesis of MXene and LDH. Ti₃C₂ MXene is a material with great potential in the field of supercapacitors. A coating structure NiCoFe-LDH/Ti₃C₂ composite material was prepared via coating nano-scaled NiCoFe-LDH on micron-scaled Ti₃C₂ MXene through surface functional groups. NiCoFe-LDH composite shows an excellent specific capacity of 1990F g-1 in 1 M KOH at a current density of 1 A g⁻¹, and maintain a specific capacity of 84.8% after 5000 cycles of charging and discharging at a current density of 10 A g⁻¹. NiCoFe-LDH/Ti₃C₂// RGO asymmetric supercapacitor (ASC) was prepared in a 1 M KOH electrolyte system with the above materials and RGO as positive and negative electrodes respectively. At power densities of 895.1 and 9000 W kg⁻¹, NiCoFe-LDH/Ti₃C₂//rGO ASC exhibits excellent energy densities of 54.4 and 32.5 W h kg⁻¹ respectively. The significance of this work is that a coating structure NiCoFe-LDH/Ti₃C₂ MXene composite morphology was successfully synthesized for the first time which showed excellent electrochemical performance in the application of supercapacitors. The proposed method may provide the possibility to synthesize other similar metal hydroxide and MXene composite structures and provide their electrochemical properties.