Nitrile functionalized disiloxanes with dissolved LiTFSI as lithium ion electrolytes with high thermal and electrochemical stability

Liquid disiloxanes functionalized with terminal nitrile groups are introduced as alternative non-volatile solvents for lithium-ion battery electrolytes in combination with LiTFSI as lithium salt. Two series of disiloxanes were investigated differing with respect to the attachment of the nitrile cont...

Full description

Saved in:
Bibliographic Details
Published in:Journal of power sources 2015-01, Vol.274, p.629-635
Main Authors: Pohl, Benjamin, Hiller, Martin M., Seidel, Sarah M., Grünebaum, Mariano, Wiemhöfer, Hans-Dieter
Format: Article
Language:English
Subjects:
Aluminum base alloys
Cathodes
Constants
Electrolytes
Lithium
Nitriles
Pitting (corrosion)
Solvents
Stability
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Liquid disiloxanes functionalized with terminal nitrile groups are introduced as alternative non-volatile solvents for lithium-ion battery electrolytes in combination with LiTFSI as lithium salt. Two series of disiloxanes were investigated differing with respect to the attachment of the nitrile containing side group to silicon, i.e. via a Si-C or a Si-O bond. Total conductivities up to 1 mS cm super(-1) at 30 [degrees]C were measured by impedance spectroscopy. Electrochemical characterization was done on half cells using LiFePO sub(4) cathodes by cyclic voltammetry and constant current cycling. Attractive issues and advantages of the investigated LiTFSI containing disiloxanes in comparison to current electrolyte solvents are: a) In spite of the presence of LiTFSI, the aluminum pitting corrosion is suppressed, b) the electrochemical stability window is extended on the cathode side up to 5.6 V vs. Li/Li+, for a LiTFSI concentration of 0.7 mol kg super(-1), c) the reported nitrile functionalized disiloxanes show excellent thermal stability with a boiling point up to 106 [degrees]C (0.1 mbar), a rather low glass transition temperature of -107 [degrees]C, while no melting/crystallization was observed.
ISSN:0378-7753
DOI:10.1016/j.jpowsour.2014.10.080