Robust cobalt phthalocyanine-based covalent organic framework/chitosan aerogel for high-performance supercapacitor

Covalent organic frameworks (COFs) usually exist in the form of powder, which is not conducive to electrical conductivity and difficult to be molded, especially into aerogel , tremendously limiting its application in supercapacitors . In this work, the robust cobalt phthalocyanine-based COF/chitosan (CoPc-COF/CS) aerogels were successfully prepared by freeze drying the water solution of CoPc-COF and 2,4,6-triformylphloroglucinol (Tp, crosslinker) in chitosan (CS). The CoPc-COF/CS aerogels not only have good mechanical strength and compressibility but also maintain the COF original crystallinity and functionalities. Notably, the porous network structure of CoPc-COF/CS aerogels provides rich active surfaces and short ion diffusion paths. Meanwhile, the rich nitrogen groups on the surface of aerogel and Co N 4 centers improve their specific capacitance in the three-electrode system. The obtained CoPc-COF/CS aerogel exhibits excellent capacitive performance (556 F g −1 at 1 A g −1 ) in the three-electrode system. Furthermore, the asymmetric supercapacitor (CoPc-COF/CS aerogel//AC ASC) assembled using CoPc-COF/CS aerogel and activated carbon (AC) electrodes exhibited a high energy density of 31.9 Wh kg −1 at 750 W kg −1 and good cycle stability (87.5 % after 5000 cycles). The capacitive performances of CoPc-COF/CS aerogel promising for practical applications in supercapacitors. • Phthalocyanine-based COFs was applied into supercapacitor. • The CoPc-COF/CS aerogels were prepared as a self-supporting electrode. • The aerogels with good compressibility and stability conducive recycling • The N, Br and Co elements of the CoPc-COF improve specific capacitance of aerogels.