Polyoxometalate-Based\nMetal–Organic Frameworks with Conductive Polypyrrole for Supercapacitors

Abstract

Metal–organic\nframeworks (MOFs) with high porosity could act as an ideal substitute\nfor supercapacitors, but their poor electrical conductivities limit\ntheir electrochemical performances. In order to overcome this problem,\nconductive polypyrrole (PPy) has been introduced and a novel nanocomposite\nresulting from polyoxometalate (POM)-based MOFs (NENU-5) and PPy has\nbeen reported. It comprises the merits of POMs, MOFs, and PPy. Finally,\nthe highly conductive PPy covering the surfaces of NENU-5 nanocrystallines\ncan effectively improve the electron/ion transfer among NENU-5 nanocrystallines.\nThe optimized NENU-5/PPy nanocomposite (the volume of Py is 0.15 mL)\nexhibits high specific capacitance (5147 mF·cm^–2), larger than that of pristine NENU-5 (432 mF·cm^–2). Furthermore, a symmetric supercapacitor device based on a NENU-5/PPy-0.15\nnanocomposite possesses an excellent areal capacitance of 1879 mF·cm^–2, which is far above other MOF-based supercapacitors.