Fluorinated compounds for use in lithium battery electrolytes
View Patent ↗Provide are fluorinated cyclic and acyclic carbonate solvent compositions such as various fluorine substituted 1,3-dioxolane-2-one compounds and fluorine substituted 1,3-dioxane-2-one compounds, which are useful as electrolyte solvents for lithium ion batteries.
1. A lithium ion battery comprising:
a liquid electrolyte;
a positive electrode; and
a negative electrode,
wherein said liquid electrolyte comprises a solvent and a lithium salt wherein the solvent comprises a compound according to the formula R—O—C(═O)—O—R′,
wherein R is C x H 2x+1 and x is an integer from 1 to 4, and
wherein R′ is —C(R h 7 )(R h 8 )CFR f 1 (CF 2 CF 2 ) n CHFR f 7 , wherein R f 1 is fluorine or C p F 2p+1 and p is an integer from 1 to 4, R f 7 is F, C p F 2p+1 , or R f 3 O(R f 4 O) m —, wherein R f 3 is C y F 2y+1 , and y is an integer from 1 to 8, and R f 4 is C q F 2q , wherein q is an integer from 1 to 4, and R h 7 and R h 8 are independently H or an alkyl group and wherein R h 7 and R h 8 are not both alkyl groups, the alkyl groups having 1 to 4 carbon atoms, m is 0 or 1, and n is 0 or 1, and such that when R h 7 and R h 8 are both hydrogen and n is 0, then R f 7 is not fluorine.
2. The lithium ion battery of claim 1 wherein R h 7 and R h 8 are both hydrogen and n is zero.
3. The lithium ion battery of claim 1 wherein one of R h 7 and R h 8 is an alkyl group, n is 1, and both R f 1 and R f 7 are fluorine.
4. The lithium ion battery of claim 1 wherein one of R h 7 and R h 8 is an alkyl group, n is zero, and R f 1 is F or C n F 2n+1 , and R f 7 and R h 8 are F, C n F 2n+1 , or R f 3 O(R f 4 O) m —.