Multicomponent hierarchical Ni-MOFs/MWCNTs@Ni/Co-LDH nanohybrid as advanced electrode material for supercapacitor

Layer double hydroxide (LDH) is a metal hydroxide with two or more metal components. It has promising prospects in supercapacitors (SCs) as electrode material due to the chemical composition adjustability, excellent ion exchangeability, good redox activity and high specific capacity. However, the further application of LDH is limited to the inferior electrochemical conductivity and slow reaction kinetics. Multiwalled carbon nanotubes (MWCNTs) as electrode materials possess excellent conductivity and distinctive hollow structure but the specific capacities are low. Metal-organic frameworks (MOFs) have abundant electrochemical active sites, multi- functionality and tunable porosity, which could accelerate the process of transporting and diffusing electrolyte ions, enhancing the specific capacitance as electrode material. Hence, in this work, MWCNTs decorated with NiMOFs were introduced into Ni/Co-LDH to fabricate multicomponent heterostructure Ni-MOFs/MWCNTs@Ni/ Co-LDH nanohybrid by in situ chemical reaction. The specific capacity of Ni-MOFs/MWCNTs@Ni/Co-LDH was 1032.0 C g- 1 at a current density of 1.0 A g- 1 and retained 66.0 % initial capacity following 5000 cycles at 5 A g- 1 . A power density of 850.0 W kg- 1 and an energy density of 28.9 Wh kg- 1 were obtained for the assembled asymmetric supercapacitor.