Fluorinated Rocksalt Cathode with Ultra‐high Active Li Content for Lithium‐ion Batteries
- Department of Chemical Engineering Waterloo Institute for Nanotechnology University of Waterloo Waterloo Ontario N2 L 3G1 Canada
- Advanced Light Source Lawrence Berkeley National Laboratory Berkeley California 94720 USA
- Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China
- Advanced Photon Source Argonne National Laboratory Lemont IL 60439 USA
- Center for Functional Nanomaterials Brookhaven National Laboratory Upton NY 11973 USA
- Department of Chemistry and Department of Computer Science University of Toronto Toronto Ontario M5S 3H6 Canada
- National Synchrotron Light Source II Brookhaven National Laboratory Upton NY 11973 USA
- Department of Chemistry McMaster University Hamilton ON L8S 4 L8 Canada
- Center of Energy Storage Materials &, Technology College of Engineering and Applied Sciences National Laboratory of Solid State Microstructures Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China
Abstract The key to increasing the energy density of lithium‐ion batteries is to incorporate high contents of extractable Li into the cathode. Unfortunately, this triggers formidable challenges including structural instability and irreversible chemistry under operation. Here, we report a new kind of ultra‐high Li compound: Li 4+ x MoO 5 F x (1≤ x ≤3) for cathode with an unprecedented level of electrochemically active Li (>3 Li + per formula), delivering a reversible capacity up to 438 mAh g −1 . Unlike other reported Li‐rich cathodes, Li 4+ x MoO 5 F x presents distinguished structure stability to immunize against irreversible behaviors. Through spectroscopic and electrochemical techniques, we find an anionic redox‐dominated charge compensation with negligible oxygen release and voltage decay. Our theoretical analysis reveals a “reductive effect” of high‐level fluorination stabilizes the anionic redox by reducing the oxygen ions in pure‐Li conditions, enabling a facile, reversible, and high Li‐portion cycling.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC02-06CH11357; DEAC02-05CH11231; SC0012704
- OSTI ID:
- 1894150
- Journal Information:
- Angewandte Chemie, Journal Name: Angewandte Chemie Vol. 134 Journal Issue: 47; ISSN 0044-8249
- Publisher:
- Wiley Blackwell (John Wiley & Sons)Copyright Statement
- Country of Publication:
- Germany
- Language:
- English
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