Separator for a rechargeable battery

Patent metadata

Field	Value
Publication number	US-10608226-B2
Application number	US-201816137699-A
Country	US
Kind code	B2
Filing date	Sep 21, 2018
Priority date	Aug 17, 2016
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

The invention provides a coating or film adapted to be arranged between a separator and at least one electrode of a rechargeable battery. The coating or film comprises a porous layer comprising a layer material having at least a first material and a second material, the first and the second materials being arranged to comprise a plurality of pores for passage of ions therethrough; and the second material is adapted to reduce in size upon drying such that porosity of the porous layer is improved or enhanced at a normal operating temperature; wherein, in response to temperature change, the layer material is adapted to undergo a first phase change during which the pores of said porous layer are adapted to substantially close to thereby substantially reduce or prevent further passage of ions.

First claim

The invention claimed is:

1. A coating or film adapted to be arranged between a separator and at least one electrode of a rechargeable battery, the coating or film comprising:
a porous layer comprising a layer material having at least a first material and a second material, the first and the second materials being arranged to comprise a plurality of pores for passage of ions therethrough; and the second material is adapted to reduce in size upon drying such that porosity of the porous layer is improved or enhanced at a normal operating temperature;
wherein, in response to temperature change, the layer material is adapted to undergo a first phase change during which the pores of said porous layer are adapted to substantially close to thereby substantially reduce or prevent further passage of ions.

2. The coating or film according to claim 1 , wherein the second material is interconnected with the first material to form a porous network comprising the pores.

3. The coating or film according to claim 1 , wherein, upon drying, a size of the first material remains substantially unchanged.

4. The coating or film according to claim 1 , wherein the second material is adapted to reduce in size by about 30 vol % to about 300 vol % after drying.

5. The coating or film according to claim 1 , wherein the layer material comprises a plurality of particles formed of at least one of the first material and the second material interspersed among one another.

6. The coating or film according to claim 5 , wherein the plurality of particles are adapted to fuse together in response to the temperature change to thereby substantially close or block the pores of the porous network.

7. The coating or film according to claim 1 , wherein porosity of the porous layer after drying is about 25% to about 75%.

8. The coating or film according to claim 1 , wherein the first material and the second material are provided at a weight ratio of about 2:1 to about 2:10.

9. The coating or film according to claim 1 , wherein the second material is formed of at least one hydrophobic monomer and at least one hydrophilic monomer.

10. The coating or film according to claim 1 , wherein the layer material is adapted to undergo the first phase change at a first temperature.

11. The coating or film according to claim 10 , wherein the first temperature is a glass-transition temperature at which the layer material starts to soften.

12. The coating or film according to claim 10 , wherein the layer material is adapted to undergo a second phase change at a second temperature higher than the first temperature, the second temperature being a melting temperature at which the layer material is melted and fallen apart.

13. The coating or film according to claim 11 , wherein the glass-transition temperature is at a range of about 80° C. to about 150° C.

14. The coating or film according to claim 12 , wherein the melting temperature is at a range of about 100° C. to about 250° C.

15. The coating or film according to claim 12 , wherein the second temperature is at least about 20° C. higher than the first temperature.

16. The coating or film according to claim 1 , wherein the layer material further comprises a third material deposited among the first and the second materials for adhering the porous layer with one or more respective surfaces of the separator and the at least one electrode.

17. The coating or film according to claim 16 , wherein the third material is adapted to cover the plurality of particles of at least one of the first and the second materials to thereby forming core-shell structures.

18. The coating or film according to claim 16 , wherein the plurality of particles of the layer material are interconnected via the third material.

19. A rechargeable battery having a separator comprising a coating or film according to claim 1 .

20. A method of manufacturing a rechargeable battery, the method comprising the step of:
providing a coating or film according to claim 1 between a separator and at least one electrode of the rechargeable battery; and drying the coating or film to thereby shrink the second material to improve or enhance porosity of the porous layer.

Assignees

• Hong Kong Applied Science & Tech Research Inst Co Ltd
• Hong Kong Applied Sciene And Tech Research Institute Co Ltd

Inventors

• Xie Laiyong
• Xiang Jing
• Lim Pau Yee

Classifications

• H01M10/0525

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

• H01M2/1653

  Electricity · mapped topic

• H01M2/1686 Primary

  Electricity · mapped topic

• H01M2/145

  Electricity · mapped topic

• H01M50/403 Primary

  Manufacturing processes of separators, membranes or diaphragms · CPC title