Nonaqueous electrolyte compositions

• US 10,916,805 B2
• Filed: 04/04/2014
• Issued: 02/09/2021
• Est. Priority Date: 04/04/2013
• Status: Active Grant

• Current Assignee: Syensqo SA
• Original Assignee: Solvay SA (Solvac SA)
• Inventors: Chen, Xudong, Dubois, Charles J., Holstein, William L., Kourtakis, Kostantinos, Roelofs, Mark Gerrit
• Primary Examiner(s): Ruddock, Ula C
• Assistant Examiner(s): Van Oudenaren, Matthew W
• Application Number:
  US14/244,984
• Publication Number:
  US 20140302402A1
• Time in Patent Office: 2,503 Days
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 2300/0034 Fluorinated solvents
• CPC Class Codes: H01M 2300/0037 Mixture of solvents
• CPC Class Codes: H01M 2300/004 Three solvents
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Electrolyte compositions comprising fluorinated acyclic carboxylic acid esters, fluorinated acyclic carbonates, and/or fluorinated acyclic ethers; co-solvents; and certain film-forming chemical compounds are described. The electrolyte compositions are useful in electrochemical cells, such as lithium ion batteries where they provide the improved performance of a combination of high capacity and high cycle life.

Claims

1. An electrolyte composition comprising:

a) at least one fluorinated solvent selected from the group consisting of;

(i) a fluorinated acyclic carboxylic acid ester represented by the formula;

R¹—

COO—

R²,

wherein R¹ represents a linear or branched alkyl group with 1, 3, 4, or 5 carbon atoms, R² represents a linear or branched alkyl group, the sum of carbon atoms in R¹ and R² is 2 to 7, at least two hydrogens in R¹ and/or R² are replaced by fluorines; and

neither R¹ nor R² contains a FCH₂ or FCH group; and

the electrolyte composition does not contain any acyclic carboxylic ester represented by the formula R¹—

COO—

R², wherein R¹ represents a linear or branched alkyl group with 2 carbon atoms;

b) at least one co-solvent selected from the group consisting of ethylene carbonate, and propylene carbonate;

c) at least one cyclic carboxylic acid anhydride selected from the group consisting of

2. The electrolyte composition of claim 1, wherein the fluorinated solvent is a fluorinated acyclic carboxylic ester and the number of carbon atoms in R¹ is 1, 3, 4, or 5.

3. The electrolyte composition of claim 1, wherein the fluorinated solvent is a fluorinated acyclic carboxylic ester, R¹ does not contain fluorine, and R² contains fluorine.

4. The electrolyte composition of claim 1, wherein the at least one cyclic carboxylic acid anhydride is selected from one or more members of the group consisting of maleic anhydride, succinic anhydride, glutaric anhydride, 2,3-dimethylmaleic anhydride, citraconic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride, 2,3-diphenylmaleic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, 2,3-dihydro-1,4-dithiono-[2,3-c]furan-5,7 dione, and phenylmaleic anhydride.

5. The electrolyte composition of claim 4, wherein the at least one cyclic carboxylic acid anhydride is maleic anhydride.

6. The electrolyte composition of claim 1, wherein the fluorinated acyclic carboxylic acid ester is selected from one or more members of the group consisting of CH₃—

COO—

CH₂CF₂H, CH₃CH₂—

COOCH₂CF₂H, F₂CHCH₂—

COO—

CH₃, F₂CHCH₂—

COO—

CH₂CH₃, CH₃—

COO—

CH₂CH₂CF₂H, CH₃CH₂—

COO—

CH₂CH₂CF₂H, F₂CHCH₂CH₂—

COO—

CH₂CH₃, and CH₃—

COO—

CH₂CF₃.

7. The electrolyte composition of claim 6, wherein the fluorinated acyclic carboxylic acid ester is 2,2-difluoroethyl acetate.

8. The electrolyte composition of claim 1, wherein the at least one cyclic carboxylic acid anhydride is present in an amount of about 0.1% to about 5.0% by weight of the total electrolyte composition.

9. The electrolyte composition of claim 1, wherein the electrolyte composition comprises 2,2-difluoroethyl acetate, ethylene carbonate, and maleic anhydride.

10. The electrolyte composition of claim 1, wherein the electrolyte composition comprises about 50% to about 80% of 2,2-difluoroethyl acetate;

about 10% to about 40% of ethylene carbonate; and

about 0.25% to about 5.0% of maleic anhydride by weight of the total electrolyte composition.

11. The electrolyte composition of claim 1, wherein the electrolyte composition comprises about 50% to about 80% of 2,2-difluoroethyl acetate, about 10% to about 40% of ethylene carbonate, about 0.25% to about 5.0% of fluoroethylene carbonate and about 0.25% to about 5.0% of maleic anhydride by weight of the total electrolyte composition.

12. An electrochemical cell comprising:

(a) a housing;

(b) an anode and a cathode disposed in said housing and in ionically conductive contact with one another;

(c) the electrolyte composition of claim 1 or claim 2 disposed in said housing and providing an ionically conductive pathway between said anode and said cathode; and

(d) a porous separator between said anode and said cathode.

13. The electrochemical cell of claim 12, wherein said electrochemical cell is a lithium ion battery.

14. The electrochemical cell of claim 13, wherein the anode is lithium titanate or graphite.

15. The electrochemical cell of claim 13, wherein the cathode comprises a cathode active material exhibiting greater than 30 mAh/g capacity in a potential range greater than 4.6 V versus a Li/Li⁺ reference electrode.

16. The electrochemical cell of claim 13, wherein the cathode comprises a cathode active material which is charged to a potential greater than or equal to 4.35 V versus a Li/Li⁺ reference electrode.

17. The electrochemical cell of claim 13, wherein the cathode comprises 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_xNi_yM_zMn_2-y-zO_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.

18. The electrochemical cell of claim 13, wherein the cathode comprises Li_aNi_bMn_cCo_dR_eO_2-fZ_f, wherein:

R is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, Zr, Ti, a rare earth element, or a combination thereof, and Z is F, S, P, or a combination thereof; and

0.8≤

a≤

1.2, 0.1≤

b≤

0.5, 0.2≤

c≤

0.7, 0.05≤

d≤

0.4, 0≤

e≤

0.2;

wherein the sum of b+c+d+e is about 1; and

00.08.

19. An electronic device, transportation device, or telecommunications device, comprising an electrochemical cell according to claim 13.

21. The electrolyte composition of claim 1, wherein the electrolyte composition comprises about 30% to 70% by weight of the fluorinated solvent, about 10% to 60% by weight co-solvent, and about 0.01% to 10% by weight cyclic carboxylic acid anhydride.

22. The electrolyte composition of claim 1, wherein the electrolyte composition is free of butyrolactone.

20. A method comprising combining to form an electrolyte composition:

a) at least one fluorinated solvent selected from the group consisting of;

(i) a fluorinated acyclic carboxylic acid ester represented by the formula;

R¹—

COO—

R²,

wherein R¹ represents a linear or branched alkyl group with 1, 3, 4, or 5 carbon atoms, R² represents a linear or branched alkyl group, the sum of carbon atoms in R¹ and R² is 2 to 7, at least two hydrogens in R¹ and/or R² are replaced by fluorines; and

neither R¹ nor R² contains a FCH₂ or FCH group; and

the electrolyte composition does not contain any acyclic carboxylic ester represented by the formula R¹—

COO—

R², wherein R¹ represents a linear or branched alkyl group with 2 carbon atoms;

b) at least one co-solvent selected from the group consisting of ethylene carbonate, and propylene carbonate;

c) at least one cyclic carboxylic acid anhydride selected from the group consisting of