Inside Front Cover: Proton Intercalation into an Open-Tunnel Bronze Phase with Near-Zero Volume Change

Abstract

Proton intercalation of Mo₃Nb₂O₁₄ bronze occurs with near-zero volume change, which arises from rotation and shrinkage of the flexible MOn framework (M = Mo, Nb) as reported by Kosuke Kawai et al. in their Research Article (e202410971). As a result, the Mo₃Nb₂O₁₄ particle maintains high crystallinity after repeating proton (de)intercalation, which contributes to high Coulombic efficiency and long-term charge/discharge operation of an aqueous proton battery.