Ultrathin Ni–Co\nBimetallic Metal–Organic\nFramework Nanobelts for High-Performance Energy Storage

Abstract

The design and advancement of nanostructured composite\nmaterials\nin a one-dimensional (1D) configuration have garnered significant\ninterest in the pursuit of high-performance supercapacitor applications.\nHerein, we present the synthesis of ultrathin 1D NiCo metal–organic\nframework (MOF) nanobelts via a solvothermal process. The resulting\nnanobelts exhibit a unique and uniformly distributed 1D morphology\ncharacterized by a high specific surface area (SSA) and exceptional\nstructural stability. Electrochemical investigations reveal that the\noptimized 1D NiCo-MOF-31 composite shows a high specific capacitance\n(<i>C</i>_s) of 1697.5 F g^–1 under 1 A g^–1 current and 696.43 under 10 A g^–1, with a superior cyclic performance over 5000 charging/discharging\ncycles. Furthermore, an asymmetric supercapacitor device (1D NiCo-MOF-31//SNAC)\nwas constructed by using S,N-codoped activated carbon (SNAC) as the\nanode and 1D NiCo-MOF-31 as the cathode material. The device demonstrates\nan impressive energy density of 26.56 Wh kg^–1 at\na power density of 750 W kg^–1 with remarkable cyclic\nstability. The exceptional electrochemical activity is due to its\n1D nanobelt morphology, which offers notable advantages such as high\nSSA, rapid ion and electron transport, etc. These inherent benefits\nposition nanobelts as highly promising candidates for advancing the\nfield of high-performance supercapacitors.