POROUS INTERLAYER FOR A LITHIUM-SULFUR BATTERY

• US 20150104690A1
• Filed: 10/11/2013
• Published: 04/16/2015
• Est. Priority Date: 10/11/2013
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Xiao, Qiangfeng, Cai, Mei
• Granted Patent: US 9,373,829 B2
• Time in Patent Office: Days
• US Class Current: 429/145
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 50/403 Manufacturing processes of separators, membranes or diaphragms
• CPC Class Codes: H01M 50/414 Synthetic resins, e.g. thermoplastics or thermosetting resins
• CPC Class Codes: H01M 50/417 Polyolefins
• CPC Class Codes: H01M 50/426 Fluorocarbon polymers
• CPC Class Codes: H01M 50/431 Inorganic material
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/446 Composite material consisting of a mixture of organic and inorganic materials
• CPC Class Codes: H01M 50/451 comprising layers of only organic material and layers containing inorganic material
• CPC Class Codes: H01M 50/454 comprising a non-fibrous layer and a fibrous layer superimposed on one another
• CPC Class Codes: H01M 50/457 comprising three or more layers
• CPC Class Codes: H01M 50/489 Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
• CPC Class Codes: H01M 50/491 Porosity
• CPC Class Codes: H01M 50/497 Ionic conductivity
• 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

Abstract

A porous interlayer for a lithium-sulfur battery includes an electronic component and a negatively charged or chargeable lithium ion conducting component. The electronic component is selected from a carbon material, a conductive polymeric material, and combinations thereof. In an example, the porous interlayer may be disposed between a sulfur-based positive electrode and a porous polymer separator in a lithium-sulfur battery. In another example, the porous interlayer may be formed on a surface of a porous polymer separator.

Claims

1. A porous interlayer for a lithium-sulfur battery, consisting of:

an electronic component selected from a carbon material, a conductive polymeric material, and combinations thereof; and

a negatively charged or chargeable lithium ion conducting component.

2. The porous interlayer as defined in claim 1 wherein the carbon material is selected from carbon nanotubes, graphene, microporous carbon, mesoporous carbon, hollow carbon spheres, and combinations thereof.

3. The porous interlayer as defined in claim 1 wherein the conductive polymeric material includes nanofibers, nanotubes, hollow spheres, or combinations thereof, the conductive polymeric material being made of polypyrrole, polythiophene, polyaniline, polyacetylene, polyphenylene vinylene, polyphenylene sulfide, or combinations thereof.

4. The porous interlayer as defined in claim 1 wherein a ratio of the electronic component to the negatively charged or chargeable lithium ion conducting component ranges from 1:

99 to 99;

1.

5. The porous interlayer as defined in claim 1 wherein a percentage of the negatively charged or chargeable lithium ion conducting component in the porous interlayer is 5 wt % or less of a total wt % of the porous interlayer.

6. The porous interlayer as defined in claim 1 wherein the negatively charged or chargeable lithium ion conducting component is selected from a sulfonated tetrafluoroethylene based fluoropolymer-copolymer, polyacrylic acid, sodium alginate, or a single lithium ion conductive polymer.

7. The porous interlayer as defined in claim 1 wherein a thickness of the porous interlayer ranges from about 10 nm to about 1000 μ

m.

8. A method for making a porous interlayer for a lithium-sulfur battery, the method comprising;

dispersing an electronic component selected from a carbon material, a conductive polymeric material, and combinations thereof in a first liquid to form a first dispersion;

exposing a porous support structure to the first dispersion, whereby the electronic component remains on a surface of the porous support structure and the first liquid filters through the porous support structure;

dispersing a negatively charged or chargeable lithium ion conducting component in a second liquid to form a second dispersion; and

exposing the porous support structure to the second dispersion, whereby the negatively charged or chargeable lithium ion conducting component remains on the surface of the porous support structure and the second liquid filters through the porous support structure.

9. The method as defined in claim 8 wherein prior to exposing the porous support structure to the first or second dispersions, the method further comprises:

mixing the first and second dispersions to form a single dispersion; and

wherein the exposing steps are accomplished simultaneously by exposing the porous support structure to the single dispersion.

10. The method as defined in claim 8 wherein the porous support structure is a polytetrafluroethylene film, a polyethylene (PE) membrane, a polypropylene (PP) membrane, a membrane including a blend of PE and PP, or multi-layered structured porous films of PE and PP.

11. The method as defined in claim 8, further comprising removing the porous support structure, thereby forming a free standing porous interlayer.

12. The method as defined in claim 8 wherein the porous support structure is a porous polymer membrane, and the method further comprises allowing the porous polymer membrane to remain in contact with the electronic component and the negatively charged or chargeable lithium ion conducting, thereby forming a separator with the porous interlayer as a coating on the porous polymer membrane.

13. A separator for a lithium-sulfur battery, comprising:

a porous polymer membrane; and

an interlayer formed on a surface of the porous membrane, the interlayer consisting of;

an electronic component selected from a carbon material, a conductive polymeric material, and combinations thereof; and

a negatively charged or chargeable lithium ion conducting component.

14. The separator as defined in claim 13 wherein the porous polymer membrane is selected from polyethylene (PE), polypropylene (PP), a blend of PE and PP, or multi-layered structured porous films of PE and PP.

15. The separator as defined in claim 13 wherein:

carbon material is selected from carbon nanotubes, graphene, microporous carbon, mesoporous carbon, hollow carbon spheres, and combinations thereof;

or

the conductive polymer material includes nanofibers, nanotubes, hollow spheres, or combinations thereof, the conductive polymer material being made of polypyrrole, polythiophene, polyaniline, polyacetylene, polyphenylene vinylene, polyphenylene sulfide, or combinations thereof.

16. The separator as defined in claim 13 wherein the negatively charged or chargeable lithium ion conducting component is selected from a sulfonated tetrafluoroethylene based fluoropolymer-copolymer, polyacrylic acid, sodium alginate, or a single lithium ion conductive polymer.

17. A lithium-sulfur battery, comprising:

a sulfur-based positive electrode;

a negative electrode;

a porous polymer separator disposed between the sulfur-based positive electrode and the negative electrode;

a porous interlayer disposed between the sulfur-based positive electrode and the porous polymer separator, the porous interlayer consisting of;

an electronic component selected from a carbon material, a conductive polymeric material, and combinations thereof; and

a negatively charged lithium ion conducting component; and

an electrolyte filing pores of the porous polymer separator and the porous interlayer.

18. The lithium-sulfur battery as defined in claim 17 wherein:

the carbon material is selected from carbon nanotubes, graphene, microporous carbon, mesoporous carbon, hollow carbon spheres, and combinations thereof;

or

the conductive polymeric material includes nanofibers, nanotubes, hollow spheres, or combinations thereof, the conductive polymeric material being made of polypyrrole, polythiophene, or polyaniline.

19. The lithium-sulfur battery as defined in claim 17 wherein a percentage of the negatively charged lithium ion conducting component in the porous interlayer is 5 wt % or less of a total wt % of the porous interlayer.

20. The lithium-sulfur battery as defined in claim 17 wherein the negatively charged lithium ion conducting component is selected from negatively charged sulfonated tetrafluoroethylene based fluoropolymer-copolymer, negatively charged polyacrylic acid, negatively charged sodium alginate, or a single lithium ion conductive polymer.