Additives for high voltage lithium ion batteries

Patent metadata

Field	Value
Publication number	US-10840552-B2
Application number	US-201815916723-A
Country	US
Kind code	B2
Filing date	Mar 9, 2018
Priority date	Dec 29, 2017
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

This invention relates to a method for preparing an electrochemical cell comprising the sequential steps of preparing a solution of a lithium salt in an non-aqueous solvent containing an additive compound, and maintaining the solution at a temperature in the range of about 20 to about 30° C. for about 5 to 10 days to form an aged electrolyte; assembling an electrochemical cell from an anode, a cathode, and the aged electrolyte; and electrochemically subjecting the electrochemical cell to formation cycling. The additive compound comprises one or more compounds selected from the group consisting of: (R 3 SiO) 3 B, (R 3 SiO) 3 XY, (R 3 SiO) 3 P, (R′O) 3 PO, (R 3 Si) 3 X′, R 3 SiOS(O) 2 R′; (R 3 Si)OC(═O)R′; wherein each R and R′ independently is a hydrocarbyl group; X is P or B; Y is O or S; X is Ti or Al. Electrochemical cells and batteries also are described.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method for preparing an electrochemical cell; the method comprising the sequential steps of:
(a) preparing a solution of a lithium salt in a non-aqueous solvent containing an additive compound, and maintaining the solution at a temperature in the range of about 20 to about 30° C. for about 5 to 10 days to form an aged electrolyte; wherein the lithium salt is present in the solution at a concentration in the range of about 0.1 molar (M) to about 3 M and the additive compound is present in the solution at a concentration in the range of about 0.0005 M to about 0.2 M;
(b) assembling an electrochemical cell by contacting an anode and a cathode with the aged electrolyte;
(c) electrochemically subjecting the electrochemical cell to formation cycling to form a solid electrolyte interface (SEI) on the anode thereof;
wherein the additive compound comprises one or more compounds selected from the group consisting of: (R 3 SiO) 3 B, (R 3 SiO) 3 XY, (R 3 SiO) 3 P, (R′O) 3 PO, (R 3 Si) 3 X′, R 3 SiOS(O) 2 R′; (R 3 Si)OC(═O)R; wherein each R and R′ independently is a hydrocarbyl group; X is P or B; Y is O or S; X′ is Ti or Al.

2. The method of claim 1 , wherein each R and R′ independently is a hydrocarbyl moiety selected from the group consisting of alkyl, aryl, aryl-substituted alkyl and alkyl-substituted aryl.

3. The method of claim 1 , wherein the additive compound comprises a compound of formula (R 3 SiO) 3 P, wherein each R independently is a hydrocarbyl group.

4. The method of claim 3 , wherein each R independently is a hydrocarbyl moiety selected from the group consisting of alkyl, aryl, aryl-substituted alkyl and alkyl-substituted aryl.

5. The method of claim 3 , wherein each R independently is a hydrocarbyl moiety selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, and phenyl.

6. The method of claim 3 , wherein each R is methyl.

7. The method of claim 3 , wherein step (a) produces a compound of formula R 3 SiOP(O) n F 2 from the additive compound; wherein each R independently is a hydrocarbyl group; and n is 0 or 1; wherein the additive is substantially free from (R 3 SiO) 3 P(O) n and (R 3 SiO) 2 P(O) n F.

8. The method of claim 7 , wherein each R independently is a hydrocarbyl moiety selected from the group consisting of alkyl, aryl, aryl-substituted alkyl and alkyl-substituted aryl.

9. The method of claim 7 , wherein each R independently is a hydrocarbyl moiety selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, and phenyl.

10. The method of claim 7 , wherein each R is methyl.

11. The method of claim 3 , wherein the lithium salt comprises at least on salt selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imidate (LiTFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium trifluoromethanesulfonate (LiTf), lithium perchlorate (LiClO 4 ), lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiDFOB), lithium tetrafluoroborate (LiBF 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium thiocyanate (LiSCN), lithium bis(fluorosulfonyl)imidate (LiFSI), lithium bis(pentafluoroethylsulfonyl)imidate (LBETI), lithium tetracyanoborate (LiB(CN) 4 ), and lithium nitrate.

12. The method claim 3 , wherein the lithium salt comprises LiPF 6 .

13. The method of claim 3 , wherein the non-aqueous solvent comprises at least one solvent selected from the group consisting of an ether, a carbonate ester, a nitrile, a sulfoxide, a sulfone, a fluoro-substituted linear dialkyl carbonate, a fluoro-substituted cyclic alkylene carbonate, a fluoro-substituted sulfolane, and a fluoro-substituted sulfone.

14. The method of claim 3 , wherein the non-aqueous solvent comprises a combination of an alkylene carbonate and a dialkyl carbonate.

Assignees

• Uchicago Argonne Llc

Inventors

• Peebles Cameron
• Shkrob Ilya A
• Liao Chen
• Abraham Daniel
• Iddir Hakim
• Garcia Juan

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0569 Primary

  characterised by the solvents · CPC title