Influence of relative humidity on the structure and electrochemical performance of sustainable LiFeSO4F electrodes for Li-ion batteries

Leiting Zhang, Jean Marie Tarascon, Moulay Tahar Sougrati, Gwenaëlle Rousse, Guohua Chen

Research output: Journal article publicationJournal articleAcademic researchpeer-review

21 Citations (Scopus)

Abstract

Material abundance and eco-efficient synthetic protocols are becoming the overriding factors for developing sustainable Li-ion batteries, and hence today there is great interest in LiFePO4. The recently reported tavorite-type LiFeSO4F cathode material, which shows a redox potential of 3.6 V and a practical capacity of ∼130 mA h g-1without the need for sophisticated carbon coating or particle downsizing, stands presently as a serious contender to LiFePO4. However, its synthesis is still not routinely reproducible. Herein, we offer a direct explanation by showing the strong effect of the room temperature relative humidity on both LiFeSO4F aging stability and its electrochemical performances. We demonstrate the complete degradation of tavorite-type LiFeSO4F into FeSO4·nH2O (n = 1, 4, 7) and LiF in environments with relative humidities greater than 62%, and also show the feasibility of triggering in situ formation of a F--free (Li)FeSO4OH phase within the cell. This work, which we also extend to the 3.9 V triplite-type LiFeSO4F polymorph, provides a foundation for achieving the consistent production and handling of LiFeSO4F electrodes in view of large-scale manufacturing. This moisture sensitivity issue, which can be mitigated by surface treatments, is inherent to sulfate-based electrode materials and the battery community must be aware of it.
Original languageEnglish
Pages (from-to)16988-16997
Number of pages10
JournalJournal of Materials Chemistry A
Volume3
Issue number33
DOIs
Publication statusPublished - 10 Jul 2015
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

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