Flower-shaped multiwalled carbon nanotubes@nickel-trimesic acid MOF composite as a high-performance cathode material for energy storage

Abstract

Metal-organic frameworks (MOFs) have received considerable attention in electrochemical fields due to their tunable morphology, open topological structure, large surface, and intense redox-activity. Herein, a novel flower-shaped multiwalled carbon nanotubes/nickel-trimesic acid composite (MWCNTs@Ni(TA)) was synthesized via one-step solvothermal method. The morphology and composition of the composite were characterized and compared with the single-component counterpart of spherical Ni(TA) by SEM, TEM, XRD, BET and FT-IR. The characterization results showed that the presence of carboxyl functionalized MWCNTs played a critical role to induce transformation of Ni(TA) from solid spherical shape in the single-component situation to the nanosheet-assembled flower shape in the composite. Electrochemical experiments showed that the flower-shaped MWCNTs@Ni(TA) composite have higher specific capacity (115 mAh g−1 at a current density of 2 A g−1) and better rate capability than the spherical Ni(TA). The MWCNTs@Ni(TA) based electrode also presented outstanding cycling stability with 81.6% specific capacity remained after 5000 charge-discharge cycles at a current density of 10 A g−1 in KOH electrolyte.