Lithium Insertion Mechanism in Iron-Based Oxyfluorides with Anionic Vacancies Probed by PDF Analysis
DUTTINE, Mathieu
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX [PHENIX]
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Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX [PHENIX]
DUTTINE, Mathieu
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX [PHENIX]
< Reduce
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX [PHENIX]
Language
en
Article de revue
This item was published in
ChemistryOpen. 2015, vol. 4, n° 4, p. 443-447
Wiley
English Abstract
The mechanism of lithium insertion that occurs in an iron oxyfluoride sample with a hexagonal–tungsten–bronze (HTB)-type structure was investigated by the pair distribution function. This study reveals that upon lithiation, ...Read more >
The mechanism of lithium insertion that occurs in an iron oxyfluoride sample with a hexagonal–tungsten–bronze (HTB)-type structure was investigated by the pair distribution function. This study reveals that upon lithiation, the HTB framework collapses to yield disordered rutile and rock salt phases followed by a conversion reaction of the fluoride phase toward lithium fluoride and nanometer-sized metallic iron. The occurrence of anionic vacancies in the pristine framework was shown to strongly impact the electrochemical activity, that is, the reversible capacity scales with the content of anionic vacancies. Similar to FeOF-type electrodes, upon de-lithiation, a disordered rutile phase forms, showing that the anionic chemistry dictates the atomic arrangement of the re-oxidized phase. Finally, it was shown that the nanoscaling and structural rearrangement induced by the conversion reaction allow the in situ formation of new electrode materials with enhanced electrochemical properties.Read less <
English Keywords
pair distribution function
ferric fluoride
anionic partitioning
cathode materials
Origin
Hal imported