Fluorine-containing solvents for lithium batteries having increased safety

US5916708A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Jurgen Besenhard · Horstmar, DE
• Konrad von Werner · Burgkirchen an der Alz, DE
• Martin Winter · Munster, DE

Key dates

• Filing date: May 9, 1997
• Grant date: Jun 29, 1999
• Expiry date: May 9, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01M2300/0034
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

The safety of secondary lithium cells is remarkedly enhanced when partially fluorinated ethers of the formulae EQU RO--(CH.sub.2).sub.m O!.sub.n --CF.sub.2 --CFH--X (I) and/or EQU X--CFH--CF.sub.2 O--(CH.sub.2).sub.m O!.sub.n --CF.sub.2 --CFH--X(II) are being used, wherein R is a straight-chain alkyl group containing 1 to 10 carbon atoms or a branched alkyl group containing 3 to 10 carbon atoms, X is fluorine, chlorine or a perfluoroalkyl group containing 1 to 6 carbon atoms, which may also contain ethereal oxygen, m is an integer from 2 to 6 and n is an integer from 1 to 8. Preferred are compounds of the formula (I), wherein R is a methyl group, X is fluorine, m is 2 and n is an integer from 1 to 3 and also compounds of the formula (II), wherein m is 2 and n is an integer from 1 to 3.