An Advanced High-Performance Ultrafast Ammonium-Ion Aqueous Battery Based on Dual-Metal Redox Open Framework Molecular Magnet.

ABSTRACT: We report a potassium manganese-iron hexacyanoferrate (KMnFeHCF) Prussian blue analog molecular magnet as a promising, low-cost, environmentally friendly cathode for metal-free ammonium-ion aqueous batteries. KMnFeHCF crystallizes in a face-centered cubic structure (Fm3m, lattice constant ≈ 10.19 Å) and exhibits a weak ferromagnetism, with Mössbauer spectroscopy confirming a mixed-valence Fe⁺³/Fe⁺² states. The material delivers a high specific capacity of ~145 mAh/g at 3 A/g, and ~130 mAh/g at 5 A/g along with excellent coulombic efficiency of 97%. Electrochemical performance is governed by reversible Fe²⁺/Fe³⁺ and Mn²⁺/Mn³⁺ redox transitions supported by the open-framework tunnel-like crystal structure which effectively accommodates structural distortions during ammo

SUBMITTER: Maiti N 

PROVIDER: S-EPMC12948221 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature