A COF-like conductive conjugated microporous poly(aniline) serving as a current collector modifier for high-performance Li-S batteries

Conducting polymers such as polyaniline have demonstrated their considerable superiorities when serving as promising sulfur host materials for Li-S batteries, owing to their strong affinity for lithium polysulfides (LiPSs) and excellent conductivity. However, less polar groups, an unstable frame structure and low specific surface area limited their electrochemical performance. Herein, a covalent organic framework (COF)-like conjugated microporous polyaniline (CMPA) with an extended π-conjugated system and permanent 3D microporosity was developed as a modified material for use in the current collector of the sulfur cathode for highly efficient Li-S batteries. This multifunctional CMPA shows the integrated nature of conjugated microporous polymers (CMPs) and PANi, ensuring exceptionally specific surface area, nitrogen-rich character, stable framework and high conductivity. Owing to these superiorities, the current collector modified by CMPA delivers a high areal capacity (7.42 mA h cm −2 ) and high energy density (202.8 W h kg cell −1 ) even under a sulfur loading of 8.72 mg cm −2 . These outcomes present a new strategy for designing advanced cathodes and also demonstrate the potential of CMPs in energy storage batteries. A COF-like CMPA was synthesized by the B-H coupling reaction, serving as the functional layer of the current collector in the sulfur cathode. Benefiting from the advantages of CMPA, the cathode achieved long-life cyclability and high energy density.