Fluorinated carbonyl compounds comprising a triple bond, methods for their manufacture and uses thereof

Abstract

Fluorinated carbonyl compounds comprising a triple bond were prepared and their use as solvent additives or solvents in lithium ion batteries, lithium air batteries, lithium sulphur batteries and supercapacitors is described. Preferred compounds contain at least one nitrile or at least one alkynyl group.

Claims

1. A compound of general formula (I),
R1-OC(O)OR2 wherein R1 is a branched or unbranched alkyl group substituted by at least one fluorine atom; wherein R2 is a branched or unbranched alkyl group substituted by at least one nitrile group or an unbranched alkynyl group.

2. The compound according to claim 1 wherein the compound is CH.sub.3CFHOC(O)OCH.sub.2CH.sub.2CN, CH.sub.3CFHOC(O)OCH.sub.2CH.sub.2CCH, or 1-fluoroethyl propargyl carbonate.

3. A method for the manufacture of a compound according to claim 1 of general formula (I),
R1-OC(O)OR2, wherein R1 is a branched or unbranched alkyl group substituted by at least one fluorine atom; wherein R2 is a branched or unbranched alkyl group substituted by at least one nitrile group or an unbranched alkynyl group; the method comprising a first step of reacting phosgene or a phosgene analogue with a compound of the general formula R1-OH to form an intermediate of the general formula R1-OC(O)X and a second step of reacting the intermediate of the general formula R1-OC(O)X with a compound of the general formula HOR2, wherein X is a leaving group.

4. The method according to claim 3, wherein the leaving group is chlorine or fluorine.

5. A solvent composition for lithium ion batteries, lithium air batteries, lithium sulfur batteries, supercapacitors or hybrid supercapacitors, the solvent composition comprising at least one solvent useful for lithium ion batteries and at least one compound according to claim 1.

6. An electrolyte composition for lithium ion batteries, lithium ail batteries, lithium sulfur batteries, supercapacitors or hybrid supercapacitors, the electrolyte composition comprising at least one compound according to claim 1, at least one solvent useful for lithium ion batteries or supercapacitors and at least one electrolyte salt.

7. A lithium ion battery, a lithium air battery or a lithium sulfur battery containing at least one compound according to claim 1.

8. A supercapacitor or hybrid supercapacitor containing at least one compound according to claim 1.

9. The compound according to claim 1, wherein R1 is 1-fluoroethyl.

10. The compound according to claim 1, wherein R2 is CH2CH2CN.

11. The compound according to claim 1, wherein R2 is CH2CH2CCH.

12. A method for the manufacture of a compound of general formula (I),
R1-OC(O)OR2 wherein R1 is a branched or unbranched alkyl group substituted by at least one fluorine atom; and wherein R2 is a branched or unbranched alkyl group substituted by at least one nitrile group or an unbranched alkynyl group; and wherein the method of manufacture comprises the step of reacting a fluoroformate of general formula II, R1OC(O)F, with an alcohol of general formula III, R2OH, to form a carbonate of general formula IV, R1OC(O)OR2.

13. A solvent additive or solvent for lithium ion batteries, lithium air batteries, lithium sulphur batteries, supercapacitors or hybrid supercapacitors comprising a compound of general formula (I),
R1-OC(O)OR2 wherein R1 is a branched or unbranched alkyl group substituted by at least one fluorine atom; wherein R2 is a branched or unbranched alkyl group substituted by at least one nitrile group or an unbranched alkynyl group.

Description

EXAMPLES

Example 1: Synthesis of 2-Cyanoethyl 1-Fluoroethyl Carbonate

(1) In a 2.5 L reactor made of Perfluoroalkoxy (PFA) equipped with a mechanical stirrer and a reflux condenser 987 g (8.1 mol) 1-fluoroethyl fluoroformate was cooled to 4 C. Over a period of 2.25 h 841 g of a mixture of pyridine and 3-hydroxypropionitrile (226 g pyridine (2.9 mol), 615 g 3-hydroxypropionitrile (8.5 mol)) was added to the 1-fluorethyl fluoroformate under stirring and cooling. The reaction temperature was kept below 60 C. After an additional 4 h of stirring, the reaction was complete. The mixture was washed with aqueous citric acid three times (500 mL, 300 mL, 200 mL) and dried with molecular sieve. After filtration 2-cyanoethyl 1-fluoroethyl carbonate is obtained as a slightly yellowish liquid (1023 g, 6.3 mol).

(2) .sup.1H NMR (500 MHz, chloroform-d) [ppm]=1.47-1.70, (ddd, J=21 Hz, 6 Hz, 3 Hz, 3H) 2.79 (td, J=6 Hz, 1 Hz, 2H), 2H), 4.28-4.49 (m, 2H), 6.34 (dqd, J=56 Hz, 5 Hz, 3 Hz, 1H).

(3) .sup.13C NMR (125 MHz, chloroform-d) [ppm]=17.8, 19.4 (d, J=23 Hz), 62.3, 103.7, 105.5, 116.2, 152.6.

(4) .sup.19F NMR (471 MHz, chloroform-d) [ppm]=121.35 (dq, J=56 Hz, 21 Hz).

Example 2: Synthesis of 1-Fluoroethyl Propargyl Carbonate

(5) A 2.5 l PFA-reactor equipped with a temperated double mantle, a reflux condenser and a mechanical stirrer was charged with 1190 g 1-fluoroethyl fluoroformate. After cooling to 3 C., a mixture of 284 g pyridine and 591 g propargyl alcohol was slowly added over a period of 2 hours. The reaction temperature was kept below 50 C. After cooling to r.t., the mixture was washed with a 30% aqueous citric acid solution three times (200 ml, 125 ml, 75 ml). The product was obtained as a colourless liquid in a yield of 1164 g (74%) with a purity>96% (GC assay).

(6) The products can optionally be further purified, e.g. by distillation, crystallization, or precipitation.