A High‐Capacity π‐Conjugated Polymer Cathode With Electron Reservoirs for Rechargeable Aqueous Zinc Batteries

ABSTRACT π‐Conjugated polymers provide a viable solution to the solubility and conductivity challenges of small‐molecule cathodes in rechargeable aqueous zinc batteries (RAZBs). However, their low active‐site utilization leads to unsatisfactory practical capacities. Herein, we have constructed a π‐conjugated polymer, poly(1,4,5,8‐tetraazaanthracene‐9,10‐dione‐[e]pyrene) (PTAP), by fusing p‐benzoquinone, pyrazine, and pyrene units. The pyrene units serve as fused‐ring π‐electron reservoirs, accommodating electrons during discharge, and facilitating the reduction of all C═O/N sites in the benzoquinone and pyrazine units. When employed as the cathode in RAZBs, PTAP delivers a considerable capacity of 416.3 mAh g −1 , corresponding to an active‐site utilization exceeding 95%. PTAP's semiconductivity minimizes the requirement for conductive additives, achieving superior specific capacity compared to previously reported organic cathodes based on the total cathode mass. Additionally, its rigid polymeric structure effectively suppress dissolution, enabling excellent cycling and static stability. This work presents a high‐capacity cathode candidate. Importantly, an effective electron reservoir strategy may inspire new designs of high‐performance organic electrode materials.