Coupling Improvement of Electronic Conductivity and Optimization of Redox‐Active Sites in Conjugated Microporous Polymers for High‐Performance Sodium‐Ion Batteries

Redox‐active organic polymers are emerging as promising cathode candidates for sodium‐ion batteries (SIBs) because of their high theoretical specific capacity, tailorable molecular structures, and environmental benignity. However, synergistically improving conductivity and enriching redox‐ active sites to simultaneously realize superior rate performance and high specific capacity still remain a critical challenge. Herein, a thiazolo[5,4‐d]thiazole‐bridged thiophene‐based conjugated microporous polymer (denoted as TzTz‐BTT) featuring extended conjugation and enriched redox‐active sites is rationally designed at the molecular level. The incorporated p‐π‐conjugated thiophene moieties not only extend the conjugated backbone to accelerate rapid charge transport and enhance electrical conductivity, but also serve as redox‐active sites for Na + storage. As a result, TzTz‐BTT delivers a high specific capacity of 294.5 mAh g −1 at 0.1 A g −1 , as well as excellent rate performance with a capacity of 114.3 mAh g −1 at 5.0 A g −1 . Furthermore, when paired with a hard carbon anode, the assembled pouch battery delivers a high specific capacity of 122.7 mAh g −1 even after 1000 cycles at 0.5 A g −1 , accompanied by an impressive capacity retention of 90.2%. This work provides valuable insights into the design of advanced CMP cathodic materials by synergistically improving electronic conductivity and surface redox‐active sites for advanced SIBs.