Duodecuple H‐Bonded NH<sub>4</sub><sup>+</sup> Storage in Multi‐Redox‐Site N‐Heterocyclic Cathode for Six‐Electron Zinc–Organic Batteries
Yehui Zhang, Ziyang Song, Ling Miao, Yaokang Lv, Lihua Gan, Mingxian Liu
Abstract
Abstract Designing multiple redox sites in electroactive organic cathodes that allow more electron transfer is a permanent target for energy storage. Here, six‐electron zinc–organic batteries are reported accessed by duodecuple H‐bonded NH 4 + storage in N‐heterocyclic dipyrazino[2,3‐f:2′,3′‐h]quinoxaline‐2,3,6,7,10,11‐hexacarbonitrile (DQH) cathode. DQH features an extended π‐conjugated aromatic planarity enriched with super electron delocalization routes and dodecahedral‐active imine/cyano motifs, achieving a high capacity up to 385 mAh g −1 at 0.5 A g −1 . Besides, DQH cathode redox‐exclusively couples with small‐hydration‐size and low‐desolvation‐energy‐barrier NH 4 + ions (0.33 nm and 0.19 eV vs 0.86 nm and 0.36 eV of Zn 2+ ) via flexible H‐bonding interactions. NH 4 + topo‐coordination enables DQH anti‐dissolution in aqueous electrolytes to avoid common capacity decay of small organic molecules, and solves the instability and low interfacial reaction kinetics issues caused by rigidly and sluggishly repeated insertion of Zn 2+ ions. This gives zinc–organic battery high‐rate ability (30 A g −1 ) and high lifespan (30 000 cycles at 10 A g −1 ).