Date of Original Version
Lithium tetramethyl borate (LTMB, LiB(OCH3)4) has been prepared and investigated as a novel cathode film forming additive to improve the performance of LiNi0.5Mn1.5O4 cathodes cycled to high potential (4.25-4.8 V). Addition of LTMB to 1.2 M LiPF6 in EC/EMC (3/7, v/v) improves the capacity retention of graphite/LiNi0.5Mn1.5O4 cells cycled at 55°C. The added LTMB is sacrificially oxidized on the surface of the cathode during the first charging cycle. Ex-situ surface analysis of the LiNi0.5Mn1.5O4 by X-ray photoelectron spectroscopy (XPS) reveals the presence of a borate based passivating layer which appears to inhibit electrolyte oxidation on the cathode surface.
Xu, M., Zhou, L., Dong, Y., Tottempudi, U., Demeaux, J., Garsuch, A., & Lucht, B. L. (2015). Improved Performance of High Voltage Graphite/LiNi0.5Mn1.5O4 Batteries with Added Lithium Tetramethyl Borate. ECS Electrochem. Lett. 4(8), A83-A86. doi: 10.1149/2.0021508eel
Available at: http://dx.doi.org/10.1149/2.0021508eel
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