Organic/inorganic composite porous membrane, and separator and electrode structure comprising the same

Patent metadata

Field	Value
Publication number	US-10797287-B2
Application number	US-201414895423-A
Country	US
Kind code	B2
Filing date	Oct 31, 2014
Priority date	Oct 31, 2013
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

The present disclosure provides an organic/inorganic composite porous membrane, comprising: one or more particles selected from inorganic particles and organic particles; and a binder polymer, wherein said one or more particles selected from inorganic particles and organic particles are bonded with each other by the binder polymer surrounding the surface of the particles, and said one or more particles are filled at a rate of 60 to 70% in the membrane.

First claim

What is claimed is:

1. A method for preparing an organic/inorganic composite porous membrane for an electrochemical device, comprising:
(S1) providing unit particles where one or more particles are selected from inorganic particles and organic particles or an agglomerate of the inorganic particles and the organic particles; coating the unit particles with a binder polymer in a solution of the binder polymer; passing the coated unit particles through a membrane into an aqueous solution; forming a slurry from the aqueous solution and the coated unit particles; and
(S2) applying the slurry and then heating the unit particles to make the unit particles be bonded with each other on a porous polymer film substrate or a porous polymer non-woven substrate.

2. The method of claim 1 , wherein the unit particles have an average diameter of 0.01 μm to 20 μm.

3. The method of claim 1 , wherein the binder polymer in the coated unit particles is present at an amount of 1 part by weight to 30 parts by weight based on 100 parts by weight of the one or more particles selected from the inorganic particles and the organic particles.

4. The method of claim 1 , wherein the inorganic particles are selected from the group consisting of inorganic particles having a dielectric constant of 5 or higher, inorganic particles having the ability to transport lithium ions, and a mixture thereof.

5. The method of claim 1 , wherein the organic particles are selected from the group consisting of polyethylene (PE), polystyrene (PS), polymethylmethacylate (PMMA), polyacetal (polyoxymethylene, POM), polyamide (PA), polycarbonate (PC), modified polyphenylene ether (m-PPE), polybutylene terephthalate (PBT), and a mixture thereof.

6. The method of claim 1 , wherein the binder polymer is selected from the group consisting of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-tri chloroethyl ene, polymethylmethacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate polyethylene-co-vinyl acetate, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, polystyrene, polyethylene, and a mixture thereof.

7. The method of claim 1 , wherein in the organic/inorganic composite porous membrane, the one or more particles selected from the inorganic particles and the organic particles are filled and bound to each other by the binder polymer, from which interstitial volumes are formed between the one or more particles, and the interstitial volumes between the one or more particles become empty spaces to form pores.

8. The method of claim 1 ,
wherein in the (S 1 ), the binder polymer and the one or more particles selected from the inorganic particles and the organic particles or the agglomerate of the inorganic particles and the organic particles are mixed in a solvent to obtain the solution, the solution is passed through the membrane with uniform pores and dropped in the aqueous solution containing a surfactant, aqueous solution maintains its temperature above a boiling point of the solvent, and the drops of the solution are solidified directly after passing through the membrane, thereby forming the coated unit particles.

9. The organic/inorganic composite porous membrane prepared according to the method of claim 1 , comprising: the one or more particles selected from the inorganic particles and the organic particles in multiple layers; and the binder polymer,
wherein the one or more particles selected from the inorganic particles and the organic particles are bonded with each other by the binder polymer completely surrounding the surface of each of the one or more particles selected from the inorganic particles and the organic particles, and the one or more particles are filled at a rate of 65% to 70% in the organic/inorganic composite porous membrane.

10. The organic/inorganic composite porous membrane of claim 9 , wherein the binder polymer is present at an amount of 1 part by weight to 30 parts by weight based on 100 parts by weight of the one or more particles selected from the inorganic particles and the organic particles.

11. The organic/inorganic composite porous membrane of claim 9 , wherein the inorganic particles are selected from the group consisting of inorganic particles having a dielectric constant of 5 or higher, inorganic particles having the ability to transport lithium ions, and a mixture thereof.

12. The organic/inorganic composite porous membrane of claim 9 , wherein the organic particles are selected from the group consisting of polyethylene (PE), polystyrene (PS), polymethylmethacylate (PMMA), polyacetal (polyoxymethylene, POM), polyamide (PA), polycarbonate (PC), modified polyphenylene ether (m-PPE), polybutylene terephthalate (PBT), and a mixture thereof.

13. The organic/inorganic composite porous membrane of claim 9 , wherein the binder polymer is selected from the group consisting of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethylmethacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate polyethylene-co-vinyl acetate, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, polystyrene, polyethylene, and a mixture thereof.

14. The organic/inorganic composite porous membrane of claim 9 , wherein in the organic/inorganic composite porous membrane, the one or more particles selected from the inorganic particles and the organic particles are filled and bound to each other by the binder polymer, from which interstitial volumes are formed between the inorganic particles and the organic particles, and the interstitial volumes between the inorganic particles and the organic particles become empty spaces to form pores.

15. The organic/inorganic composite porous membrane of claim 9 , wherein the organic/inorganic composite porous membrane has a thickness of 0.5 μm to 50 μm.

16. The electrochemical device, comprising a cathode, an anode, and a separator interposed between the cathode and the anode, wherein the separator is the organic/inorganic composite porous membrane of claim 9 .

17. The electrochemical device, comprising a cathode, an anode, and a separator interposed between the cathode and the anode,
wherein the separator comprises the porous polymer film substrate or the porous polymer non-woven substrate having multiple pores, and the organic/inorganic composite porous membrane of claim 9 , formed on at least one surface of the porous polymer film substrate or the porous polymer non-woven substrate.

18. An electrode structure, comprising an electrode current collector; an electrode active material layer formed on at least one surface of the electrode current collector; and the organic/inorganic composite porous membrane of claim 9 , formed on another surface of the electrode current collector.

19. The electrochemical device, comprising a cathode, an anode, and an electrolyte solution, wherein at least one of the cathode and the anode is the electrode structure of claim 18 .

Assignees

• Lg Chemical Ltd

Inventors

• Jin Sun-Mi
• Yu Hyung-Kyun
• Lee Joo-Sung

Classifications

• C08J5/2206 Primary

  based on organic and/or inorganic macromolecular compounds · 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

• H01M50/454

  comprising a non-fibrous layer and a fibrous layer superimposed on one another · CPC title

• H01M50/417

  Polyolefins · CPC title