Nitrogen‐Induced Hydrogen Bonding Supramolecular Network for Ultra‐Stable Ammonium Ion Storage

Abstract Aqueous ammonium ion batteries (AAIBs) are emerging as sustainable energy storage systems due to their inherent safety and eco‐friendliness. Organic electrode materials demonstrate significant potential as anode materials due to their structural diversity, eco‐friendly, and abundant redox‐active moieties. However, their practical application is hindered by low specific capacity and poor cycling stability. In this study, we introduced 2,8,14‐trinitrodiquinoxalino[2,3‐a:2’,3’‐c]phenazine (HATNTN), a nitro‐functionalized π‐conjugated aromatic structure, as a host material for enhancing NH 4 + storage. The synergistic integration of nitro groups and aromatic frameworks enables dual enhancements: robust NH 4 + coordination via a two‐step redox mechanism and enhanced dissolution resistance via hydrogen‐bonding supramolecular network. HATNTN anode demonstrates a remarkable capacity of 203.4 mAh g −1 at 1 A g −1 and an exceptional cycle life of 30,000 cycles at 20 A g −1 . Moreover, HATNTN//VO300 full battery delivers a stable specific capacity of 106.2 mAh g −1 over 30,000 cycles at 3 A g −1 , with a cycle life exceeding 2500 h and a capacity retention rate of 88.1%. Combining in situ spectroscopy and density functional theory calculations, we elucidate the critical role of nitro‐induced hydrogen bonding in stabilizing NH 4 + storage interfaces. This study establishes a supramolecular design paradigm for durable organic anodes, advancing high‐performance AAIBs toward practical applications.