NH4+ Charge Carrier Coordinated H‐Bonded Organic Small Molecule for Fast and Superstable Rechargeable Zinc Batteries

Abstract

AbstractOrganic small molecules as high‐capacity cathodes for Zn‐organic batteries have inspired numerous interests, but are trapped by their easy‐dissolution in electrolytes. Here we knit ultrastable lock‐and‐key hydrogen‐bonding networks between 2, 7‐dinitropyrene‐4, 5, 9, 10‐tetraone (DNPT) and NH4+ charge carrier. DNPT with octuple‐active carbonyl/nitro centers (H‐bond acceptor) are redox‐exclusively accessible for flexible tetrahedral NH4+ ions (H‐bond donator) but exclude larger and rigid Zn2+, due to a lower activation energy (0.14 vs. 0.31 eV). NH4+ coordinated H‐bonding chemistry conquers the stability barrier of DNPT in electrolyte, and gives fast diffusion kinetics of non‐metallic charge carrier. A stable two‐step 4e− NH4+ coordination with DNPT cathode harvests a high capacity (320 mAh g−1), a high‐rate capability (50 A g−1) and an ultralong life (60,000 cycles). This finding points to a new paradigm for H‐bond stabilized organic small molecules to design advanced zinc batteries.