Enhancement of surface stability of lithium manganese oxide spinel by silyl-group functionalized fluoride-responsive ionic liquid additives

Abstract

Spinel-structured lithium manganese oxides are considered as promising cathode material, however, their widespread commercial application remains hampered by their poor surface instability. To overcome these problems, we designed and synthesized task-specific ionic liquid additives that can effectively scavenge trace amounts of fluoride in the cell. Addition of ionic liquid additives in the electrolyte significantly improves cycling retention. H-1- and F-19-nuclear magnetic resonance spectroscopy measurements and inductively coupled plasma mass spectrometry elemental analysis collaboratively provides clear evidence that the ionic liquid additives selectively suppress parasitic reactions of the electrolyte with the surface of lithium manganese oxides cathode. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.