A Novel Electrolyte Salt Additive for Lithium-Ion Batteries with Voltages Greater than 4.7 V
by Yunchao Li, Shun Wan, Gabriel M. Veith, Raymond R. Unocic, Mariappan Parans Paranthaman, Sheng Dai, Xiao-Guang Sun
Lithium bis(2-methyl-2-fluoromalonato)borate (LiBMFMB), as an additive for LiNi0.5Mn1.5O4, exhibits improved efficiencies and cycling stability. Cyclic voltammograms indicate the cells with additive form good solid-electrolyte interphases (SEIs) during the first cycle, whereas no additive cell needs more cycles to form a functional SEI. X-ray photoelectron spectroscopy reveals LiBMFMB could reduce the decomposition of LiPF6 salt and solvents, resulting in thinner SEI.