Microlayer membranes, improved battery separators, and methods of manufacture and use

Patent metadata

Field	Value
Publication number	US-11056750-B2
Application number	US-201615773201-A
Country	US
Kind code	B2
Filing date	Nov 11, 2016
Priority date	Nov 11, 2015
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

In accordance with at least selected embodiments, a battery separator or separator membrane comprises one or more co-extruded multi-microlayer membranes optionally laminated or adhered to another polymer membrane. The separators described herein may provide improved strength, for example, improved puncture strength, particularly at a certain thickness, and may exhibit improved shutdown and/or a reduced propensity to split.

First claim

We claim:

1. A battery separator for a lithium battery comprising:
at least one dry-process microporous polymer membrane comprising a plurality of co-extruded porous polymer microlayers with a thickness of less than 2 microns; and
at least two other dry-process microporous polymer membranes, wherein
the at least one dry-process microporous polymer membrane comprising a plurality of co-extruded porous polymer microlayers with a thickness of less than 2 microns and the at least two other dry process microporous polymer membranes are laminated to one another.

2. The battery separator of claim 1 wherein the at least two other dry-process microporous polymer membranes comprise at least one selected from a monolayer dry-process microporous polymer membrane and another dry-process microporous polymer membrane comprising a plurality of porous polymer microlayers having a thickness of less than 2 microns.

3. The battery separator of claim 2 , wherein at least three microporous dry-process polymer membranes of co-extruded polymer microlayers with a thickness of less than 2 microns are laminated together to form the battery separator.

4. The battery separator of claim 3 , wherein the at least three said microporous dry-process polymer membranes of co-extruded polymer microlayers with a thickness less than 2 microns each comprise at least three polymer microlayers.

5. The battery separator of claim 1 wherein said at least one microporous polymer dry-process membrane comprising a plurality of co-extruded porous polymer microlayers with a thickness of less than 2 microns has at least three microlayers with a thickness of less than 2 microns.

6. The battery separator of claim 1 wherein at least one of said microporous dry-process polymer membranes of co-extruded polymer microlayers of less than 2 microns is made of one or more polyolefins.

7. The battery separator of claim 1 wherein at least one of said microporous dry-process polymer membranes of co-extruded polymer microlayers is made up of coextruded dry-process polyolefin microlayers with a thickness of less than 2 microns.

8. A lithium battery comprising the battery separator of claim 1 .

9. A secondary lithium battery comprising the battery separator of claim 1 .

10. A battery separator comprising one or more dry-process microporous polymer co-extruded multi-microlayer-membranes with the microlayers having a thickness of less than 2 microns, wherein
the one or more dry-process microporous polymer co-extruded multi-microlayer membranes with microlayers having a thickness of less than 2 microns are laminated to at least two other dry-process polymer membranes, which may be a dry-process microporous polymer co-extruded multi-microlayer-membranes with microlayers having a thickness of less than 2 microns, and
wherein the battery separator provides at least one of the following: improved strength in comparison to a conventional trilayer membrane, improved shutdown in comparison to a conventional trilayer membrane, and a reduced propensity to split in comparison to a conventional trilayer membrane.

11. A lithium battery comprising the battery separator of claim 10 .

12. A separator membrane comprises one or more dry-process co-extruded multi-microlayer polymer membranes laminated to at least two other dry-process polymer membranes, which may be another dry-process co-extruded multi-microlayer polymer membrane, wherein
the separator membrane exhibits at least one of the following: improved strength in comparison to a conventional trilayer membrane, improved puncture strength in comparison to a conventional trilayer membrane, improved shutdown in comparison to a conventional trilayer membrane, and a reduced propensity to split in comparison to a conventional trilayer membrane.

13. A lithium battery comprising the separator membrane of claim 12 .

Assignees

• Celgard Llc

Inventors

• Xiao Kang Karen
• Penegar Eric Joseph
• Kondo Takahiko
• Nark Robert
• White Eric Robert
• Zhang Xiaomin
• Stokes Kristoffer K

Classifications

• H01M10/0525 Primary

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

• H01M50/494

  Tensile strength · CPC title

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/451

  comprising layers of only organic material and layers containing inorganic material · CPC title

• H01M50/491 Primary

  Porosity · CPC title