A Bipolar Covalent Organic Framework Cathode Enabling a Six‐Electron Redox Process for Wide‐Temperature Sodium‐Ion Batteries

ABSTRACT Sodium‐ion batteries (SIBs) are promising for large‐scale energy storage because of the natural abundance and low cost of sodium. However, the development of cathodes that combine high redox‐site utilization with prolonged cycling across a wide temperature range remains challenging. Herein, we develop a heteroporous bipolar triphenylamine−benzoquinone covalent organic framework (TPBQ–COF)/carbon nanotube (CNT) composite cathode, TPBQ–COF@CNT, for wide‐temperature SIBs. The framework incorporates carbonyl groups and triphenylamine units as complementary n‐type and p‐type redox centers, while the CNT network improves electrical connectivity throughout the electrode. The ordered porous skeleton further provides accessible pathways for electrolyte penetration and ion migration. TPBQ–COF@CNT exhibits an average capacity decay of only 0.0012% per cycle over 15000 cycles at 5 A g −1 . Even in the full‐cell configuration, reversible capacities of 189 and 85 mAh g −1 are preserved after 200 cycles at 50°C and 500 cycles at −20°C, respectively. We identify carbonyl reduction and triphenylamine oxidation as the complementary reactions underlying the overall six‐electron redox process, with Na + and PF 6 − participating at distinct states of charge. These findings clarify how molecularly encoded cation and anion storage can remain electrochemically accessible during prolonged cycling over a wide temperature range.