Electrolyte for lithium batteries and its use, and method for increasing the safety of lithium batteries

摘要

An electrolyte system for safer lithium batteries, with conductive lithium salt(s) and electrolyte liquid(s) containing partly fluorinated carbamate(s) of formula: (R<1>)(R<2>)N-C(=O)OR<3> (I), (in which R<1>, R<2> = linear 1-6 carbon (C) alkyl, branched 3-6C alkyl or 3-7C cycloalkyl; or R<1> and R<2> may be combined directly or with N and/or O to form a 3- to 7-membered ring which may also contain additional N atoms saturated with 1-3C alkyl, and in which the ring carbons may also carry 1-3C alkyl groups; one or more hydrogens in R<1> and R<2> may also be replaced by fluorine atoms; R<3> = partly- or per-fluorinated linear 1-6C alkyl or branched 3-6C alkyl, or partly fluorinated 3-7C cycloalkyl (optionally substituted with 1 or more 1-6C alkyl groups)). Also claimed are: (i) secondary lithium batteries with a greater level of safety containing the electrolyte system; and (ii) a method for increasing the safety of such batteries by using this system as the electrolyte.