Ion conducting polymers

• US 5,300,374 A
• Filed: 08/31/1992
• Issued: 04/05/1994
• Est. Priority Date: 08/31/1992
• Status: Expired due to Fees

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Grimes, Frederick R., Trosky, Michael Jr., Agrawal, Anoop, Allemand, Pierre-Marc
• Primary Examiner(s): KALAFUT, STEPHEN J
• Application Number:
  US07/938,858
• Time in Patent Office: 582 Days
• Field of Search: 429/192, 252/62.2, 427/386
• US Class Current: 429/312
• CPC Class Codes: C08L 2666/22 Macromolecular compounds not provided for in C08L2666/16 - C08L2666/20
• CPC Class Codes: C08L 71/02 Polyalkylene oxides
• CPC Class Codes: G02F 1/1525 characterised by a particular ion transporting layer, e.g. electrolyte
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An ion conducting polymer composition is described which exhibits electrical conductivities of at least 10^-6 S/cm and has good optical properties and is easily processable. The composition comprises a PEO-based block copolymer and a dissociable lithium salt. The invention also includes a laminate formed from the ion conducting polymer composition, and related methods of forming.

Claims

1. An ion conducting polymer composition comprising:

a block copolymer of the formula R'"'"'--(CH₂ CH₂ O)_n --R", wherein the molecular weight of said block copolymer is less than about 5000, n is from about 5 to about 34, and R'"'"' and R" are flexible units; and

an effective amount of a dissociable lithium salt.

2. An ion conducting polymer composition in accordance with claim 1 wherein said dissociable lithium salt is selected from the group comprising LiPF₆, LiBF₄, LiBr, LiN(SO₂ CF₃)₂, LiI, LiNO₃, LiSCN, LiB(C₆ H₅)₄, LiAsF₆, LiCF₃ COO, LiClO₄, LiCF₃ SO₃, LiSO₃ (CF₂)₃ SO₃ Li, and Li₂ S.

3. An ion polymer composition in accordance with claim 2 wherein said R'"'"' and said R" are both polypropylene oxide.

4. An ion conducting polymer composition in accordance with claim 3 wherein the molar ratio of ethylene oxide in said block copolymer to lithium cation is from about 6:

1 to about 80;

1.

5. An ion conducting polymer composition in accordance with claim 1 further comprising:

a compatible plasticizer.

6. An ion conducting polymer composition in accordance with claim 5, wherein said plasticizer is selected from the group comprising propylene carbonate, ethylene glycol, glycerol, tetraethylene glycol, polyethylene glycol, propylene triol and propylene/ethylene triol.

7. An ion conducting polymer composition in accordance with claim 1 further comprising:

a silane coupling agent.

8. An ion conducting polymer composition in accordance with claim 7 wherein said silane coupling agent is of the formula X'"'"'--(CH₂)_m ---Si(OR'"'"'")₃ ;

m is from about 2 to about 6;

X'"'"' is selected from the group comprising glycidoxy, amino, mercapto, hydroxyl and acrylate; and

R'"'"'" is selected from the group comprising --CH₃ and --CH₂ CH₃.

9. An ion conducting polymer composition in accordance with claim 1 wherein said end groups R'"'"' and R" are selected from the group comprising polypropylene oxide, polyethyleneimine, polyphosphazine, and polysiloxane.

10. An ion conducting polymer composition in accordance with claim 1 wherein the ratio of the number of moles of ethylene oxide in said block copolymer to the number of moles of lithium cations in said dissociable lithium salt is from about 6:

1 to about 80;

1.

11. An ion conducting polymer composition in accordance with claim 10 wherein the molar ratio of ethylene oxide in said block copolymer to lithium cation is from about 6:

1 to about 20;

1.

12. An ion conducting polymer composition in accordance with claim 1 wherein said block copolymer has a molecular weight less than about 2500.

13. An ion conducting polymer composition in accordance with claim 1 further comprising:

dangling branches primarily attached to at least one of said R'"'"' and R" groups, said dangling branches of the formula CH₃ (CH₂ CH₂ X)_p Z;

wherein p is from about 0 to about 10;

X is selected from the group comprising oxygen, nitrogen, and sulfur; and

Z is selected from the group comprising epoxy, glycidoxy, amino, mercapto, hydroxyl, and acrylate.

14. A method of forming an ion conducting polymeric laminate between a first and a second substrate, each said substrate having two faces, said method comprising:

preparing an ion conducting polymer composition comprising a block copolymer and an effective amount of a dissociable lithium salt, said block copolymer being of the formula R'"'"'--(CH₂ CH₂ O)_n --R", wherein the molecular weight of said block copolymer is less than about 5000, n is from about 5 to about 34, and R'"'"' and R" are flexible units;

depositing said composition onto one of said faces of said first substrate;

contacting one of said faces of said second substrate with said composition deposited upon said first substrate such that a thin film of said composition is formed between said first and said second substrates; and

curing said composition.

15. A method of forming an ion conducting polymeric laminate in accordance with claim 14 wherein said R'"'"' and said R" are selected from the group comprising polypropylene oxide, polyethyleneimine, polyphosphazine, and polysiloxane.

16. A method of forming an ion conducting polymeric laminate in accordance with claim 15 wherein said R'"'"' and said R" are both polypropylene oxide.

17. A method of forming an ion conducting polymeric laminate in accordance with claim 14 wherein the ratio of the number of moles of ethylene oxide in said block copolymer to the number of moles of lithium cations in said dissociable lithium salt is from about 6:

1 to about 80;

1.

18. A method of forming an ion conducting polymeric laminate in accordance with claim 17 wherein the ratio of the number of moles of ethylene oxide in said block copolymer to the number of moles of lithium cations in said dissociable lithium salt is from about 6:

1 to about 20;

1.

19. A method of forming an ion conducting polymeric laminate in accordance with claim 14 wherein said dissociable lithium salt is selected from the group comprising LiPF₆, LiBF₄, LiBr, LiN(SO₂ CF₃)₂, LiI, LiNO₃, LiSCN, LiB(C₆ H₅)₄, LiAsF₆, LiCF₃ COO, LiClO₄, LiCF₃ SO₃, LiSO₃ (CF₂)₃ SO₃ Li, and Li₂ S.

20. A method of forming an ion conducting polymeric laminate in accordance with claim 14 wherein said dissociable lithium salt is LiClO₄.

21. A method of forming an ion conducting polymeric laminate in accordance with claim 14 wherein said dissociable lithium salt is LiCF₃ SO₃.

22. A method of forming an ion conducting polymeric laminate in accordance with claim 14 wherein said block copolymer has a molecular weight less than about 2500.

23. An ion conducting polymeric laminate comprising:

at least one substrate having at least one face; and

a layer of ion conducting polymer composition comprising an ion conducting polymer and an effective amount of a dissociable lithium salt, said polymer composition contacting said one face of said substrate, wherein said ion conducting polymer comprises a block copolymer of the formula R'"'"'--(CH₂ CH₂ O)_n --R", the molecular weight of said block copolymer is less than about 5000, n is from about 5 to about 34, and R'"'"' and R" are flexible units.

24. An ion conducting polymer composition comprising:

an ethylene oxide block copolymer having end groups R'"'"' and R", said end groups being flexible units, said copolymer having a molecular weight less than about 5000; and

an effective amount of a dissociable lithium salt, wherein said composition before curing exhibits a viscosity of less than about 100 Poise and after curing, said composition exhibits a conductivity of at least about 10^-6 S/cm, and a luminous transmittance of at least about 70%.