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High Voltage LiNi0.5Mn0.3Co0.2O2/Graphite Cell Cycled at 4.6 V with a FEC/HFDEC‐Based Electrolyte |
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| Authors: | Meinan He Chi‐Cheung Su Zhenxing Feng Li Zeng Tianpin Wu Michael J Bedzyk Paul Fenter Yan Wang Zhengcheng Zhang |
| Institution: | 1. Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL, USA;2. Department of Mechanical Engineering, Worcester Polytechnic Institute, Worcester, MA, USA;3. School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR, USA;4. Applied Physics Program, Northwestern University, Evanston, IL, USA;5. X‐Ray Science Division, Argonne National Laboratory, Argonne, IL, USA;6. Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA |
| Abstract: | A high voltage LiNi0.5Mn0.3Co0.2O2/graphite cell with a fluorinated electrolyte formulation 1.0 m LiPF6 fluoroethylene carbonate/bis(2,2,2‐trifluoroethyl) carbonate is reported and its electrochemical performance is evaluated at cell voltage of 4.6 V. Comparing with its nonfluorinated electrolyte counterpart, the reported fluorinated one shows much improved Coulombic efficiency and capacity retention when a higher cut‐off voltage (4.6 V) is applied. Scanning electron microscopy/energy dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy data clearly demonstrate the superior oxidative stability of the new electrolyte. The structural stability of the bulk cathode materials cycled with different electrolytes is extensively studied by X‐ray absorption near edge structure and X‐ray diffraction. |
| Keywords: | electrode/electrolyte interface fluorinated electrolytes LiNi0 5Mn0 3Co0 2O2 cathode oxidation stability post‐test analysis |