Polymorphism in Weberite Na₂Fe₂F₇ and its Effects on Electrochemical Properties as a Na-Ion Cathode.

ABSTRACT: Weberite-type sodium transition metal fluorides (Na₂M²⁺M'³⁺F₇) have emerged as potential high-performance sodium intercalation cathodes, with predicted energy densities in the 600-800 W h/kg range and fast Na-ion transport. One of the few weberites that have been electrochemically tested is Na₂Fe₂F₇, yet inconsistencies in its reported structure and electrochemical properties have hampered the establishment of clear structure-property relationships. In this study, we reconcile structural characteristics and electrochemical behavior using a combined experimental-computational approach. First-principles calculations reveal the inherent metastability of weberite-type phases, the close energetics of seve

SUBMITTER: Foley EE 

PROVIDER: S-EPMC10174150 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature