Redox-Bipolar Polyimide Two-Dimensional Covalent Organic Framework Cathodes for Durable Aluminium Batteries

Emerging rechargeable aluminium batteries (RABs) offer a sustainable option for next-generation energy storage technologies with low cost and exemplary safety. However, the development of RABs is restricted by the limited availability of high-performance cathode materials. Herein, we report two polyimide two-dimensional covalent organic frameworks (2D-COFs) cathodes with redox-bipolar capability in RAB. The optimal 2D-COF electrode achieves a high specific capacity of 132 mAh g(-1). Notably, the electrode presents long-term cycling stability (with a negligible approximate to 0.0007 % capacity decay per cycle), outperforming early reported organic RAB cathodes. 2D-COFs integrate n-type imide and p-type triazine active centres into the periodic porous polymer skeleton. With multiple characterizations, we elucidate the unique Faradaic reaction of the 2D-COF electrode, which involves AlCl2+ and AlCl4- dual-ions as charge carriers. This work paves the avenue toward novel organic cathodes in RABs.

Automated summary

This study reports the application of two polyimide two-dimensional covalent organic frameworks (2D-COFs) cathodes in rechargeable aluminium batteries (RABs). The optimal 2D-COF electrode exhibits a high specific capacity of 132 mAh g(-1) and demonstrates long-term cycling stability. This work paves the way for novel organic cathodes in RABs.