Redox Donor-Acceptor Conjugated Microporous Polymers as Ultralong-Lived Organic Anodes for Rechargeable Air Batteries.

Polymer-air batteries have emerged as a new generation of green and safe battery, but current anodes mainly focus on limited choices of nonporous linear polymers, which usually suffer from inferior ion transfer and insufficient stability, thus constraining their development. Herein, we report a new redox donor-acceptor (D-A) conjugated microporous polymer (AQ-CMP) by the C-C coupling of anthraquinone as A and benzene as D and demonstrate the first use of CMP materials as efficient ultralong-lived organic anodes for rechargeable air batteries. By constructing a D-A octupole interconnected network throughout the CMP skeleton, AQ-CMP is endowed with not only favorable electronic modulation for enhanced electron transport and n-doping activity compared to linear counterparts, but also high density of active sites for maximizing the formula-weight-based redox capability. This coupled with highly cross-linked and porous structure of CMP, leads to markedly-improved electrochemical performance. Thus, the CMP anode delivers a 96% theoretical capacity up to 202 mAh g-1 at 2 A g-1 and retains 115 mAh g-1 at 20 A g-1, along with a remarkable 100 % retention over 60000 charge/discharge cycles - superior to all reported polymer anodes. The assembled CMP-air full cell yields a stable and high capacity with full capacity recovery after only refreshing cathodes, while the decoupled electrolyte and cathode design boosts the discharge voltage and voltage efficiency to 1 V and 85.7%, surpassing those of the existing polymer-air batteries. This work highlights not only a new class of organic active anode but also a fresh design idea, which is anticipated to boost the development of polymer-air batteries.