Multi-H-bonded self-assembled superstructures for ultrahigh-capacity and ultralong-life all-organic ammonium-ion batteries

Abstract

All-organic ammonium-ion batteries (AOBs), utilizing lightweight organic electrodes and small, hydrated NH₄⁺ charge carriers, are promising candidates for next-generation energy storage. However, the limited NH₄⁺-accessible redox-active motifs in organics with high coordination barriers present significant challenges to the advancement of AOBs. Here, we designed multi-H-bonded donor–acceptor self-assembled ultralow-coordination-barrier organic superstructures (OSs) by integrating six-electron melem modules (H-bond donors) and three-electron cyanuric acid units (H-bond acceptors) via in-plane hydrogen bonding and out-of-plane π–π stacking. These OSs, featuring a low-energy-bandgap conjugated planar configuration and long-range π-electron delocalization pathways, enabled nearly complete utilization (99.3%) of intrinsic redox-active carbonyl/imine motifs with an ultralow activation energy (0.16 eV). Consequently, a high-kinetics and ultrastable 15-e⁻ NH₄⁺ coordination mechanism was activated within the OSs cathode, delivering an ultrahigh capacity (393 mA h g⁻¹_cathode) and exceptional cycling stability (60 000 cycles). Notably, the superior performance metrics of the OSs electrode enabled state-of-the-art AOBs with a record capacity (213 mA h g⁻¹) and an unprecedented lifespan (100 000 cycles). This work provides new insights into the structural engineering of multi-active, low-coordination-barrier OSs for advanced aqueous batteries.