Conjugated Phthalocyanine‐Based Mesoporous Covalent Organic Frameworks for Efficient Anodic Lithium Storage

Abstract Organic anode materials have been recognized as promising candidates for low‐cost and sustainable lithium‐ion batteries (LIBs), which however suffer from the inferior cycling stability and low conductivity with unsatisfactory LIBs performance. Herein, two conjugated phthalocyanine‐based covalent organic frameworks (COFs), namely CoPc‐Ph‐COF and CoPc‐3Ph‐COF, are synthesized by the nucleophilic substitution reaction of hexafluorophthalocyanine cobalt (II) (CoPcF 16 ) with 1,2,4,5‐tetrahydroxybenzene and 9,10‐dimethyl‐2,3,6,7‐tetrahydroxyanthracene, respectively. Powder X‐ray diffraction and electron microscopy analysis reveal the crystalline porous structure of both COFs with a pore size of 1.6‐2.4 nm, enabling facile ion transportation. Immersion experiments demonstrate the excellent stability of both COFs. I–V curve measurement discloses the superb conductivity of both COFs due to their fully π‐conjugated frameworks. These merits, in combination with their N‐rich skeleton, endow the two COFs with excellent anodic Li + storage performance in terms of high specific capacities, superb rate performance, and good cycling stability. In particular, CoPc‐3Ph‐COF suggests a large reversible capacity of 1086 mA h g −1 at 100 mA g −1 , superior to most reported organic LIBs anodes, exhibiting its promising application in high‐performance LIBs.