Nonaqueous liquid electrolyte

• US 7,498,102 B2
• Filed: 06/12/2002
• Issued: 03/03/2009
• Est. Priority Date: 03/22/2002
• Status: Active Grant

• Current Assignee: Quallion, LLC (EnerSys), Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Original Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Inventors: Hyung, Yoo-Eup, Tsukamoto, Hisashi, Amine, Khalil, Vissers, Donald R., Oh, Bookeun
• Primary Examiner(s): Dove; Tracy
• Application Number:
  US10/167,940
• Publication Number:
  US 20030180625A1
• Time in Patent Office: 2,456 Days
• Field of Search: 429/300, 429/313, 429/317, 429/307, 429/347, 252/62.2
• US Class Current: 429/313
• CPC Class Codes: C08L 83/12 containing polyether sequences
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01G 9/022 Electrolytes; Absorbents
• CPC Class Codes: H01M 10/0431 Cells with wound or folded electrodes H01M10/045 takes precedence
• CPC Class Codes: H01M 10/052 Li-accumulators
• 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 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 10/38 Construction or manufacture
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 6/181 with polymeric electrolytes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Disclosed is a nonaqueous and nonvolatile liquid type polymeric electrolyte comprising poly(siloxane-g-ethylene oxide). This electrolyte provides significant safety and stability. The present invention solves the problems of volatility, flammability and chemical reactivity of lithium ion type electrolytes. The disclosed electrolyte exhibits excellent stability, conductivity and low impedance characteristics. The electrolyte comprises a new class of structural siloxane polymers with one or more poly(ethylene oxide) side chains. The inorganic siloxanes comprising the main backbone of the copolymers are thermally very stable and resistant to decomposition by heat. Because the main chain of the disclosed class of electrolytes is an Si—O linkage, initiation of the combustion cycle is inhibited or prevented.

Claims

1. A battery, comprising:

an electrolyte that includes a poly(siloxane-g-ethylene oxide) with repeating units represented by general formula

2. The battery of claim 1, wherein an average molecular weight of the poly(siloxane-g-ethylene oxide) does not exceed 20,000 g/mol.

3. The battery of claim 1, wherein at least one salt is a lithium salt.

4. The battery of claim 1, wherein the dissolved salt includes at least one quatemary ammonium salt having an anion selected from the group consisting of:

ClO₄⁻

, BF₄⁻

, AsF₆⁻

, PF₆⁻

, CF₃SO₃⁻

, (CF₃SO₂)₂N⁻

, (CF₃SO₂)₃C⁻

, (SO₂C₂F₅)₂N⁻

, PF₃(C₂F₅)₃⁻

, PF₃(CF₃)₃⁻

, and B(C₂O₄)₂⁻

.

5. The battery of claim 1, wherein the salt includes LiClO₄,LiBF₄, LiAsF₆, LiPF₆ , LiCF₃SO₃, Li(CF₃SO₂)₂N, LiC(CF₃SO₂)₃, LiN(SO₂C₂F₅)₂, LiPF₃(C₂F₅)₃, LiPF₃(CF₃)₃, LiB(C₂O₄)₂, or mixtures thereof.

6. The battery of claim 1, wherein at least one salt is a lithium bis(chelato)borate having five to seven membered rings.

7. The battery of claim 1, wherein the electrolyte is non-volatile.

8. The battery of claim 1, wherein the electrolyte has an ionic conductivity of at least 6×

10<sup>−

4</sup> S/cm at room temperature and at least 8.4×

10<sup>−

4</sup> S/cm at 37°

C.

9. The battery of claim 1, wherein the battery is a secondary battery.

10. The battery of claim 1, further comprising:

a lithium metal oxide or lithium metal phosphate positive electrode, at least one porous separator, and at least one lithium-carbon, lithium-alloy, or lithium metal negative electrode.

11. The secondary battery of claim 9, wherein at least one salt is a lithium salt.

12. The battery of claim 1, wherein the dissolved salt includes LiCF₃SO₃.

13. The battery of claim 1, wherein the dissolved salt includes Li(CF₃SO₂)₂N.

14. The battery of claim 1, wherein the dissolved salt includes LiC(CF₃SO₂)₃.

15. The battery of claim 1, wherein the dissolved salt includes LiN(SO₂C₂F₅)₂.

16. The battery of claim 1, wherein the dissolved salt includes LiPF₆.

17. The battery of claim 1, wherein the dissolved salt includes LiAsF₆.

18. The battery of claim 1, wherein the dissolved salt includes LiBF₄.

19. The battery of claim 1, wherein the dissolved salt includes LiClO₄.

20. The electrochemical device of claim 9, wherein the dissolved salt includes at least one electrolyte salt from the following group:

LiClO₄, LiBF₄, LiAsF₆, LiPF₆, LiCF₃SO₃, Li(CF₃ SO₂)₂N, LiC(CF₃SO₂)₃, LiN(SO₂C₂F₅)₂, LiPF₃(C₂F₅)₃, LiPF₃(CF₃)₃,LiB(C₂O₄)₂.

21. The battery of claim 1, wherein the dissolved salt includes LiPF₃(C₂F₅)₃.

22. The battery of claim 1, wherein the dissolved salt includes LiPF₃(CF₃)₃.

23. The battery of claim 1, wherein the dissolved salt includes LiB(C₂O₄)₂.

24. The battery of claim 1, wherein R′

is an alkyl group.