Breaking the low-temperature limit: an amino-engineered HATN anode for -80 °C aqueous alkaline batteries via robust...

Developing high-performance aqueous alkaline batteries for extreme environments remains a formidable challenge. Herein, we report a triamino-substituted hexaazatrinaphthalene (HATN-3NH₂) as a tailor-made anode for alkaline systems. Unlike hydroxyl-functionalized analogues that suffer from rapid dissolution in alkaline electrolytes, the amino group ensures exceptional chemical stability while its electron-donating nature effectively lowers the redox potential to -1.12 vs. Hg/HgO. Crucially, the introduced amino groups construct a robust intermolecular hydrogen-bond network that significantly enhances reaction kinetics and preserves ionic conductivity at ultra-low temperatures, a feature absent in unmodified hexaazatrinaphthalene (HATN), which exhibits rapid performance decay in cold conditions. Consequently, the HATN-3NH₂//Ni(OH)₂ full cell delivers a specific capacity of 254.8 mAh g^-1 at 0.5 A g^-1, a high discharge plateau (1.24 V), and outstanding cycling stability (39,000 cycles). Most notably, the battery demonstrates record-breaking low-temperature adaptability, delivering a high specific capacity of 185 mAh g^-1 at -80 °C and 0.1 A g^-1, with stable cycling for over 1500 cycles, which represents the best reported performance for aqueous alkaline batteries to date. This work elucidates the irreplaceable role of amino functionalization in simultaneously achieving low potential, high stability, and cold tolerance, providing a precise molecular design strategy for extreme-environment energy storage.