Multi-H-Bonded Self-Assembled Superstructures for Ultrahigh-Capacity and Ultralong-Life All-Organic Ammonium-Ion Batteries

Abstract

All-organic ammonium-ion batteries (AOBs) with light organic electrodes and small-hydrated-sized NH4+ charge carriers are up-and-coming for next-generation energy storage. However, the low NH4+-accessible redox-active motifs of organics with high coordination barriers pose significant challenges for advancing AOBs. Here we design multi-H-bonded donor-acceptor self-assembled ultralow-coordination-barrier organic superstructures (OSs) by fusing six-electron melem modules (H-bond donor) and three-electron cyanuric acid units (H-bond acceptor) via in-plane H-bonding and out-of-plane π-π stacking. OSs with low-energy-bandgap conjugated planar configuration and long-range π-electron delocalization paths promise full utilization (99.3%) of built-in redox-active carbonyl/imine motifs with an ultralow activation energy (0.16 eV). Consequently, a high-kinetics and ultrastable 15 e− NH4+ coordination mechanism within OSs cathode is initiated, liberating ultrahigh capacity (393 mAh g−1cathode) and ultralong stability (60,000 cycles). Significantly, the superior metrics of OSs electrode enable the state-of-the-art AOBs with record capacity (213 mAh g−1) and unprecedented lifespan (100,000 cycles). This work offers new insights into the structural engineering of multi-active low-coordination-barrier OSs for advanced aqueous batteries.