ELECTROLYTES FOR LOW IMPEDANCE, WIDE OPERATING TEMPERATURE RANGE LITHIUM-ION BATTERY MODULE

• US 20150221977A1
• Filed: 02/04/2015
• Published: 08/06/2015
• Est. Priority Date: 02/05/2014
• Status: Active Grant

• Current Assignee: California Institute of Technology, CPS Technology Holdings, LLC
• Original Assignee: California Institute of Technology, Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Hallac, Boutros, Smart, Marshall C., Krause, Frederick C., Metz, Bernhard M., Bugga, Ratnakumar V., Jiang, Junwei
• Granted Patent: US 9,947,960 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 10/0568 characterised by the solutes
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2300/0034 Fluorinated solvents
• CPC Class Codes: H01M 2300/004 Three solvents
• CPC Class Codes: H01M 2300/0042 Four or more solvents
• CPC Class Codes: H01M 2300/0091 in the form of mixtures
• 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

A lithium ion battery cell includes a housing, a cathode disposed within the housing, wherein the cathode comprises a cathode active material, an anode disposed within the housing, wherein the anode comprises an anode active material, and an electrolyte disposed within the housing and in contact with the cathode and anode. The electrolyte consists essentially of a solvent mixture, a lithium salt in a concentration ranging from approximately 1.0 molar (M) to approximately 1.6 M, and an additive mixture. The solvent mixture includes a cyclic carbonate, an non-cyclic carbonate, and a linear ester. The additive mixture consists essentially of lithium difluoro(oxalato)borate (LiDFOB) in an amount ranging from approximately 0.5 wt % to approximately 2.0 wt % based on the weight of the electrolyte, and vinylene carbonate (VC) in an amount ranging from approximately 0.5 wt % to approximately 2.0 wt % based on the weight of the electrolyte.

Claims

1. A lithium ion battery cell, comprising:

a housing;

a cathode disposed within the housing, wherein the cathode comprises a cathode active material;

an anode disposed within the housing, wherein the anode comprises an anode active material; and

an electrolyte disposed within the housing and in contact with the cathode and anode, wherein the electrolyte consists essentially of;

a solvent mixture comprising a cyclic carbonate, an non-cyclic carbonate, and a linear ester;

a lithium salt in a concentration ranging from approximately 1.0 molar (M) to approximately 1.6M; and

an additive mixture consisting essentially of lithium difluoro(oxalato)borate (LiDFOB) in an amount ranging from approximately 0.5 wt % to approximately 2.0 wt % based on the weight of the electrolyte, and vinylene carbonate (VC) in an amount ranging from approximately 0.5 wt % to approximately 2.0 wt % based on the weight of the electrolyte.

2. The lithium ion battery cell of claim 1, wherein the solvent mixture consists essentially of:

the cyclic carbonate in an amount between approximately 5 vol % and approximately 30 vol % based on the total volume of the solvent mixture;

a first non-cyclic carbonate and a second non-cyclic carbonate, wherein the first and second non-cyclic carbonates together represent between approximately 50 vol % and approximately 80 vol % of the total volume of the solvent mixture; and

the linear ester in an amount between approximately 5 vol % and approximately 20 vol %, based on the total volume of the solvent mixture, wherein the volume percentage of the cyclic carbonate is greater than or approximately equal to the volume percentage of the linear ester.

3. The lithium ion battery cell of claim 2, wherein the cyclic carbonate is ethylene carbonate (EC), the first non-cyclic carbonate is ethyl methyl carbonate (EMC), the second non-cyclic carbonate is dimethyl carbonate (DMC), the linear ester is methyl butyrate (MB), and the lithium salt is lithium hexafluorophosphate (LiPF₆).

4. The lithium ion battery cell of claim 3, wherein the solvent mixture is EC/EMC/DMC/MB (20:

30;

40;

10 vol %), LiDFOB is present in an amount of approximately 0.5 wt % based on the weight of the electrolyte, VC is present in an amount of approximately 1 wt % based on the weight of the electrolyte, and LiPF₆ is in a concentration of approximately 1.2 M.

5. The lithium ion battery cell of claim 1, wherein the solvent mixture consists essentially of:

a first cyclic carbonate and a second cyclic carbonate, wherein the first and second cyclic carbonates together represent between approximately 10 vol % and approximately 30 vol % of the total volume of the solvent mixture;

the non-cyclic carbonate in an amount between approximately 10 vol % and approximately 30 vol % of the total volume of the solvent mixture; and

the linear ester in an amount between approximately 50 vol % and approximately 70 vol %, based on the total volume of the solvent mixture.

6. The lithium ion battery cell of claim 5, wherein the volume percentage of the non-cyclic carbonate is approximately equal to the combined volume percentage of the first and second non-cyclic carbonates.

7. The lithium ion battery cell of claim 5, wherein the volume percentage of the linear ester is greater than the combined volume percentage of the first and second non-cyclic carbonates.

8. The lithium ion battery cell of claim 5, wherein the first cyclic carbonate is fluoroethylene carbonate (FEC) and the second cyclic carbonate is ethylene carbonate (EC), and FEC and EC are present in approximately equal volume percentages.

9. The lithium ion battery cell of claim 8, wherein the linear ester is MB, and the non-cyclic carbonate is EMC or DMC.

10. The lithium ion battery cell of claim 1, wherein the anode active material comprises a titanate-based material or a graphite-based material.

11. The lithium ion battery cell of claim 10, wherein the electrolyte produces a solid electrolyte interface (SEI) layer at the anode that is less resistive than would be obtained using lithium bis(oxalato)borate (LiBOB) in place of the LiDFOB.

12. The lithium ion battery cell of claim 1, wherein the cathode active material comprises a lithium nickel cobalt manganese oxide (NMC) active material, a lithium cobalt oxide (LCO) active material, a lithium metal oxide spinel (LMO-spinel) active material, or any combination thereof.

13. A lithium ion battery cell, comprising:

a housing;

a cathode disposed within the housing, wherein the cathode comprises a cathode active material;

an anode disposed within the housing, wherein the anode comprises an anode active material; and

an electrolyte disposed within the housing and in contact with the cathode and anode, wherein the electrolyte comprises a solvent mixture, a lithium salt in a concentration ranging from approximately 1.0 molar (M) to approximately 1.6 M, and lithium difluoro(oxalato)borate (LiDFOB) in an amount ranging from approximately 0.5 wt % to approximately 2.0 wt % based on the weight of the electrolyte; and

wherein the solvent mixture comprises a cyclic carbonate, a non-cyclic carbonate, and a linear ester, and wherein the cyclic carbonate consists essentially of fluoroethylene carbonate (FEC).

14. The lithium ion battery cell of claim 13, wherein the solvent mixture consists essentially of:

FEC in an amount between approximately 5 vol % and approximately 30 vol % based on the total volume of the solvent mixture;

the non-cyclic carbonate in an amount between approximately 5 vol % and approximately 30 vol % based on the total volume of the solvent mixture; and

the linear ester in an amount between approximately 50 vol % and approximately 70 vol % based on the total volume of the solvent mixture.

15. The lithium ion battery cell of claim 14, wherein FEC and the non-cyclic carbonate are present in approximately equal volume percentages.

16. The lithium ion battery cell of claim 13, wherein the non-cyclic carbonate is ethyl methyl carbonate (EMC).

17. The lithium ion battery cell of claim 13, wherein the linear ester is methyl butyrate (MB), methyl propionate (MP), or ethyl propionate (EP).

18. The lithium ion battery cell of claim 13, wherein the linear ester is EP.

19. The lithium ion battery cell of claim 18, wherein the electrolyte is such that the lithium ion battery cell is less resistive, at a depth of discharge percentage (% DOD) ranging between approximately 0% and approximately 75% and at a temperature below approximately −

25°

C., than would be obtained using MB or MP in place of the EP.

20. The lithium ion battery cell of claim 13, wherein the electrolyte consists essentially of the solvent mixture, the lithium salt, and LiDFOB.

21. The lithium ion battery cell of claim 20, wherein the solvent mixture is FEC/EMC/MB (20:

20;

60 vol %), FEC/EMC/MP (20;

20;

60 vol %), or FEC/EMC/EP (20;

20;

60 vol %).

22. The lithium ion battery cell of claim 13, wherein the electrolyte is 1.20 M LiPF₆ in FEC/EMC/MB (20:

20;

60 vol %)+1 wt % LiDFOB, or 1.20 M LiPF₆+0.10M LiDFOB in FEC/EMC/MP (20;

20;

60 vol %), or 1.20M LiPF₆ in FEC/EMC/EP (20;

20;

60 vol %)+1 wt % LiDFOB.

23. A lithium ion battery cell, comprising:

a housing;

a cathode disposed within the housing, wherein the cathode comprises a cathode active material;

an anode disposed within the housing, wherein the anode comprises a titanate-based active material; and

an electrolyte disposed within the housing and in contact with the cathode and anode, wherein the electrolyte comprises a solvent mixture, a lithium salt in a concentration ranging from approximately 1.0 molar (M) to approximately 1.6 M, and lithium difluoro(oxalato)borate (LiDFOB) in an amount ranging from approximately 0.5 wt % to approximately 2.0 wt % based on the weight of the electrolyte;

wherein the solvent mixture comprises a cyclic carbonate, an non-cyclic carbonate, and a linear ester, wherein the cyclic carbonate consists essentially of propylene carbonate (PC).

24. The lithium ion battery cell of claim 23, wherein the solvent mixture consists essentially of:

PC in an amount between approximately 5 vol % and approximately 30 vol % based on the total volume of the solvent mixture;

a first non-cyclic carbonate and a second non-cyclic carbonate, wherein the first and second non-cyclic carbonates together represent between approximately 50 vol % and approximately 80 vol % of the total volume of the solvent mixture; and

the linear ester in an amount between approximately 5 vol % and approximately 20 vol %, based on the total volume of the solvent mixture, wherein the volume percentage of the PC is greater than or approximately equal to the volume percentage of the linear ester.

25. The lithium ion battery cell of claim 24, wherein the volume percentage of the PC is less than or approximately equal to the total volume percentage of the first and second non-cyclic carbonates.

26. The lithium ion battery cell of claim 24, wherein the electrolyte consists essentially of the solvent mixture, the lithium salt, and LiDFOB.

27. The lithium ion battery cell of claim 24, wherein the solvent mixture is PC/EMC/DMC/MB (20:

30;

40;

10 vol %).