Cathodic dehalogenation polymerization of 2′,3′,5′,6′-tetrafluoro-4,4″-diiodo-1,1′:4′,1″-terphenyl on zinc metal surface for anode protection

Fluorine-containing poly(p-phenylene) (CityU-42) films on zinc surfaces were directly synthesized using a cathodic dehalogenation C-C coupling strategy. The as-prepared polymers can effectively protect the zinc substrate in aqueous zinc-ion batteries. Because CityU-42 is rich in the electronegative fluorine group, it can attract the uniform deposition and rapid diffusion of Zn2+ on the surface of the anode. Moreover, a large number of benzene rings provide certain mechanical strength, enabling the protective layer to inhibit the growth of dendrites. As a result, the symmetric Zn Zn cell used CityU-42@Zn can stably cycle for over 1,900 h under 5 mA cm-2 and 1 mAh cm-2, while the CityU-42@Zn V2O5 full cells maintain high capacity retention after 800 cycles at 5 A g-1. The results highlight the potential of synthesizing conjugated polymers using cathodic dehalogenation technology, paving the way for further advancement in the field of energy storage technology.