Nonaqueous electrolyte compositions comprising cyclic carbonate and non-fluorinated acyclic carbonate

Patent metadata

Field	Value
Publication number	US-11476502-B2
Application number	US-201716317918-A
Country	US
Kind code	B2
Filing date	Jul 6, 2017
Priority date	Jul 15, 2016
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

Disclosed herein are electrolyte compositions comprising: a) a first solvent comprising a cyclic carbonate; b) a second solvent comprising a non-fluorinated acyclic carbonate; c) at least one electrolyte component selected from: i) a fluorinated acyclic carboxylic acid ester; ii) a fluorinated acyclic carbonate; iii) a fluorinated acyclic ether; or iv) a mixture thereof; and d) an electrolyte salt; wherein the electrolyte component is present in the electrolyte composition in the range of from about 0.05 weight percent to about 10 weight percent, based on the total weight of the first and second solvents.

First claim

What is claimed is:

1. An electrolyte composition comprising:
a) a first solvent comprising a cyclic carbonate, wherein the cyclic carbonate comprises 4-fluoroethylene carbonate;
b) a second solvent comprising a non-fluorinated acyclic carbonate;
c) at least one electrolyte component selected from
i) a fluorinated acyclic carboxylic acid ester;
ii) a fluorinated acyclic carbonate;
iii) a fluorinated acyclic ether; or
iv) a mixture thereof; and

d) an electrolyte salt;
wherein the first solvent comprising the cyclic carbonate is present in the electrolyte composition in the range of from 20 to 35 weight percent, based on the total weight of the first and second solvents;
wherein the second solvent comprising the non-fluorinated acyclic carbonate is present in the electrolyte composition in the range of from 65 to 80 weight percent, based on the total weight of the first and second solvents; and
wherein the electrolyte component is present in the electrolyte composition in the range of from about 0.05 weight percent to about 10 weight percent, based on the total weight of the first and second solvents.

2. The electrolyte composition of claim 1 , wherein the cyclic carbonate further comprises ethylene carbonate; propylene carbonate; vinylene carbonate; vinyl ethylene carbonate; dimethylvinylene carbonate; ethyl propyl vinylene carbonate; 4,5-difluoro -1,3-dioxolan-2-one; 4,5-difluoro-4-methyl-1,3-dioxolan-2-one; 4,5-difluoro-4,5-dimethyl-1,3-dioxolan-2-one; 4,4-difluoro-1,3-dioxolan-2-one; or 4,4,5-trifluoro-1,3-dioxolan-2-one.

3. The electrolyte composition of claim 1 , wherein the non-fluorinated acyclic carbonate comprises dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, or ethyl methyl carbonate.

4. The electrolyte composition of claim 1 , wherein the electrolyte component comprises a fluorinated acyclic carboxylic acid ester represented by the formula:
R 1 —COO—R 2 ,

wherein
i) R 1 is H, an alkyl group, or a fluoroalkyl group;
ii) R 2 is an alkyl group or a fluoroalkyl group;
iii) either or both of R 1 and R 2 comprises fluorine; and
iv) R 1 and R 2 , taken as a pair, comprise at least two carbon atoms but not more than seven carbon atoms.

5. The electrolyte composition of claim 4 , wherein R 1 and R 2 , taken as a pair, further comprise at least two fluorine atoms, with the proviso that neither R 1 nor R 2 contains a FCH 2 —group or a —FCH— group.

6. The electrolyte composition of claim 4 , wherein the fluorinated acyclic carboxylic acid ester comprises CH 3 —COO—CH 2 CF 2 H, CH 3 CH 2 —COO—CH 2 CF 2 H, F 2 CHCH 2 —COO—CH 3 , F 2 CHCH 2 —COO—CH 2 CH 3 , CH 3 —COO—CH 2 CH 2 CF 2 H, CH 3 CH 2 —COO—CH 2 CH 2 CF 2 H, F 2 CHCH 2 CH 2 —COO—CH 2 CH 3 , CH 3 —COO—CH 2 CF 3 , CH 3 CH 2 —COO—CH 2 CF 2 H, CH 3 —COO— CH 2 CF 3 , H—COO—CH 2 CF 2 H, H—COO—CH 2 CF 3 , or mixtures thereof.

7. The electrolyte composition of claim 6 , wherein the fluorinated acyclic carboxylic acid ester comprises CH 3 —COO—CH 2 CF 2 H.

8. The electrolyte composition of claim 7 , further comprising lithium bis(oxalato)borate, ethylene sulfate, and maleic anhydride.

9. The electrolyte composition of claim 1 , wherein the electrolyte component comprises a fluorinated acyclic carbonate represented by the formula:
R 3 —OCOO—R 4 ,

wherein

i) R 3 is a fluoroalkyl group;
ii) R 4 is an alkyl group or a fluoroalkyl group;
iii) R 3 and R 4 , taken as a pair, comprise at least two carbon atoms but not more than seven carbon atoms.

10. The electrolyte composition of claim 8 , wherein R 3 and R 4 , taken as a pair, further comprise at least two fluorine atoms, with the proviso that neither R 3 nor R 4 contains a FCH 2 — group or a —FCH— group.

11. The electrolyte composition of claim 9 , wherein the fluorinated acyclic carbonate comprises CH 3 —OC(O)O—CH 2 CF 2 H, CH 3 —OC(O)O—CH 2 CF 3 , CH 3 —OC(O)O—CH 2 CF 2 CF 2 H, HCF 2 CH 2 —OCOO—CH 2 CH 3 , CF 3 CH 2 —OCOO—CH 2 CH 3 , or mixtures thereof.

12. The electrolyte composition of claim 11 , wherein the fluorinated acyclic carbonate comprises CH 3 —OC(O)O—CH 2 CF 2 H.

13. The electrolyte composition of claim 1 , wherein the electrolyte component comprises a fluorinated acyclic ether represented by the formula:
R 5 —O—R 6 ,

wherein
i) R 5 is a fluoroalkyl group;
ii) R 6 is an alkyl group or a fluoroalkyl group;
iii) R 5 and R 6 , taken as a pair, comprise at least two carbon atoms but not more than seven carbon atoms.

14. The electrolyte composition of claim 1 , wherein the electrolyte component is present in the electrolyte composition in the range of from about 0.05 weight percent to about 5 weight percent, based on the total weight of the first and second solvents.

15. The electrolyte composition of claim 1 , further comprising
an additive selected from a lithium boron compound, a cyclic sultone, a cyclic sulfate, a cyclic carboxylic acid anhydride, or a combination thereof.

16. The electrolyte composition of claim 15 , wherein the electrolyte component comprises a fluorinated acyclic carboxylic acid ester represented by the formula:
R 1 —COO—R 2 ,

wherein
i) R 1 is H, an alkyl group, or a fluoroalkyl group;
ii) R 2 is an alkyl group or a fluoroalkyl group;
iii) either or both of R 1 and R 2 comprises fluorine; and
iv) R 1 and R 2 , taken as a pair, comprise at least two carbon atoms but not more than seven carbon atoms.

17. An electrochemical cell comprising:
(a) a housing;
(b) an anode and a cathode disposed in the housing and in ionically conductive contact with one another;
(c) the electrolyte composition of claim 1 disposed in the housing and providing an ionically conductive pathway between the anode and the cathode; and
(d) a porous separator between the anode and the cathode.

18. The electrochemical cell of claim 17 , wherein the electrochemical cell is a lithium ion battery.

19. The electrochemical cell of claim 18 , wherein the cathode comprises a cathode active material exhibiting greater than 30 mAh/g capacity in the potential range greater than 4.6 V versus a Li/Li + reference electrode, or a cathode active material which is charged to a potential greater than or equal to 4.35 V versus a Li/Li + reference electrode.

20. The electrochemical cell of claim 18 , wherein the cathode comprises:
a) a lithium-containing manganese composite oxide having a spinel structure as active material, the lithium-containing manganese composite oxide being represented by the formula:
Li x Ni y M z Mn 2−y−z O 4−d ,

wherein x is 0.03 to 1.0; x changes in accordance with release and uptake of lithium ions and electrons during charge and discharge; y is 0.3 to 0.6; M comprises one or more of Cr, Fe, Co, Li, Al, Ga, Nb, Mo, Ti, Zr, Mg, Zn, V, and Cu; z is 0.01 to 0.18, and d is 0 to 0.3; or
b) a composite material represented by the structure of Formula:
x(Li 2−w A 1−v Q w+v O 3−e ).(1−x)(Li y Mn 2−z M z O 4−d )

wherein:
x is about 0.005 to about 0.1;
A comprises one or more of Mn or Ti;
Q comprises one or more of Al, Ca, Co, Cr, Cu, Fe, Ga, Mg, Nb, Ni, Ti, V, Zn, Zr or Y;
e is 0 to about 0.3;
v is 0 to about 0.5 w is 0 to about 0.6;
M comprises one or more of Al, Ca, Co, Cr, Cu, Fe, Ga, Li, Mg, Mn, Nb, Ni, Si, Ti, V, Zn, Zr or Y;
d is 0 to about 0.5;
y is about 0 to about 1; and
z is about 0.3 to about 1; and
wherein the Li y Mn 2−z M z O 4−d component has a spinel structure and the Li 2−w Q w+v A 1−v O 3−e component has a layered structure; or

Assignees

• Solvay

Inventors

• Burkhardt Stephen E
• Liu Jun J
• Kim Sang-Hwan
• Kourtakis Kostantinos

Classifications

• H01M10/0569 Primary

  characterised by the solvents · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M2300/0042

  Four or more solvents · CPC title

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M2004/028

  Positive electrodes · CPC title