Sulfur-enriched conjugated microporous polymers as air cathode for high efficient and stable rechargeable zinc-air battery

Conjugated microporous polymers (CMPs) are a unique class of materials with both extended π-conjugation, permanent microporous skeleton and abundant electrochemical active sites, which have shown great potential as organic electrode in the rechargeable metal-air batteries. In this study, we design and synthesize two benzotrithiophene and bithiophene-based CMPs (BTT-TP, BTT-TPF) for the cathode of Zn-air batteries, and both CMPs have same polymeric backbone and high sulfur(S) content of up to 39 wt%. Without metal atom doping and carbonation, the BTT-TPF cathode based Zn-air battery show a power density of 77 mW cm⁻², energy density of 600.4 mAh g⁻¹, and excellent cycling stability of over 2700 cycle, which is among the best performance in the air cathodes for Zn-air battery. This study proposes a novel design strategy for CMPs to be used as the cathode in the Zn-air batteries, and also demonstrates the great potential of CMP electrode in high performance rechargeable batteries.