Lithium–Iron (III) Fluoride Battery with Double Surface Protection |
| |
| Authors: | Enbo Zhao Oleg Borodin Xiaosi Gao Danni Lei Yiran Xiao Xiaolei Ren Wenbin Fu Alexandre Magasinski Kostiantyn Turcheniuk Gleb Yushin |
| |
| Institution: | 1. School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA;2. Electrochemistry Branch, Sensor and Electron Devices Directorate, Power and Energy Division, U.S. Army Research Laboratory, Adelphi, MD, USA;3. School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA;4. School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, USA;5. Engineering Laboratory for the Next Generation Power and Energy Storage Batteries, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P. R. China;6. School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, China;7. School of Physical Science and Technology, Lanzhou University, Lanzhou, China |
| |
| Abstract: | Lithium–metal fluoride batteries promise significantly higher energy density than the state‐of‐the‐art lithium‐ion batteries and lithium–sulfur batteries. Unfortunately, commercialization of metal fluoride cathodes is prevented by their high resistance, irreversible structural change, and rapid degradation. In this study, a substantial boost in metal fluoride (MF) cathode stability by designing nanostructure with two layers of protective shells—one deposited ex situ and the other in situ is demonstrated. Such methodology achieves over 90% capacity retention after 300 charge–discharge cycles, producing the first report on FeF3 as a cathode material, where a very high capacity utilization in combination with excellent stability is approaching the level needed for practical applications of FeF3. The cathode solid electrolyte interphase (CEI) containing lithium oxalate and B? F bond containing anions is found to effectively protect the cathode material from direct contact with electrolytes, thus greatly suppressing the dissolution of Fe. Quantum chemistry and molecular dynamics calculations provide unique insights into the mechanisms of CEI layer formation. As a result, this work not only demonstrates unprecedented performance, but also provides the reader with a better fundamental understanding of electrochemical behavior of MF cathodes and the positive impact observed with the application of a lithium bis(oxalato)borate salt in the electrolyte. |
| |
| Keywords: | electrolyte additives FeF3 LiBoB metal fluorides simulations |
|
|
