Cobalt-Based Layered Metal–Organic Framework as an Ultrahigh Capacity Supercapacitor Electrode Material

Metal–organic frameworks (MOFs) have recently received increasing interest due to their potential application in the energy storage and conversion field. Herein, cobalt-based layered MOF ({[Co­(Hmt)­(tfbdc)­(H₂O)₂]·(H₂O)₂}_<i>n</i>, Co–LMOF; Hmt = hexamethylenetetramine; H₂tfbdc = 2,3,5,6-tetrafluoroterephthalic acid) has been evaluated as an electrode material for supercapacitors. The Co–LMOF electrode exhibits a high specific capacitance and excellent cycling stability. Its maximum specific capacitance is 2474 F g^–1 at a current density of 1 A g^–1, and the specific capacitance retention is about 94.3% after 2000 cycles. The excellent electrochemical property may be ascribed to the intrinsic nature of Co–LMOF, enough space available for the storage and diffusion of the electrolyte, and the particles of nanoscale size