Heat-resistant and high-tenacity ultrafine fibrous separation layer, method for manufacturing same, and secondary cell using same

• US 9,293,749 B2
• Filed: 11/03/2010
• Issued: 03/22/2016
• Est. Priority Date: 11/03/2009
• Status: Active Grant

• Current Assignee: Amogreentech Co., Ltd.
• Original Assignee: Amogreentech Co., Ltd.
• Inventors: Seo, In Yong, Jo, Byung Gwang, Kim, Yun Hye, Jung, Yong Sik
• Primary Examiner(s): Eggerding, Alix
• Application Number:
  US13/505,633
• Publication Number:
  US 20120225358A1
• Time in Patent Office: 1,966 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01G 9/02 Diaphragms; Separators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 50/406 Moulding; Embossing; Cutting
• CPC Class Codes: H01M 50/42 Acrylic resins
• CPC Class Codes: H01M 50/426 Fluorocarbon polymers
• CPC Class Codes: H01M 50/434 Ceramics
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/494 Tensile strength
• 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
• CPC Class Codes: Y10T 442/696 Including strand or fiber material which is stated to have specific attributes [e.g., heat or fire resistance, chemical or solvent resistance, high absorption for aqueous compositions, water solubility, heat shrinkability, etc.]

Abstract

Provided is an ultrafine fibrous porous separator with heat resistance and high-strength and a manufacturing method thereof, which enables mass-production of a heat-resistant and high-strength ultrafine fibrous separator by using an air-electrospinning (AES) method, and to a secondary battery using the same. The method of manufacturing a heat-resistant and high-strength ultrafine fibrous porous separator includes the steps of: air-electrospinning a mixed solution of 50 to 70 wt % of a heat-resistant, polymer material and 30 to 50 wt % of a swelling polymer material, to thereby form a porous web of a heat-resistant ultrafine fiber in which the heat-resistant polymer material and the swelling polymer material are consolidated in an ultrafine fibrous form; performing drying to control a solvent and moisture that remain on the surface of the porous web; and performing thermal compression on the dried porous web at a temperature of between 170° C. and 210° C. so as to obtain the separator.

Claims

1. A heat-resistant and high-strength ultrafine fibrous porous separator manufacturing method:

comprising the steps of;

air-electrospinning a mixed solution of a heat-resistant polymer material and a swelling polymer material, to thereby form a porous web made of a heat-resistant ultrafine fiber in which the heat-resistant polymer material and the swelling polymer material are consolidated in an ultrafine fibrous form;

performing drying to control a solvent and moisture that remain on the surface of the porous web, to thereby control the strength and porosity of the separator; and

performing thermal compression of the dried porous web so as to obtain the separator,

wherein the air-electrospinning is performed by stirring the heat-resistant polymer material and the swelling polymer material in a mixing tank to prevent a phase separation, until the heat-resistant polymer material and the swelling polymer material are mixed with a solvent to then be spinned.

2. The porous separator manufacturing method of claim 1, wherein the mixed solution comprises 50-70 wt % of the heat-resistant polymer and 30-50 wt % of the swelling polymer material.

3. The porous separator manufacturing method of claim 1, wherein an air pressure applied to a nozzle of a spin nozzle pack during the air-electrospinning is set in the range of 0.1 to 0.6 Mpa.

4. The porous separator manufacturing method of claim 1, wherein the air-electrospinning is performed by an independent air spray that takes place for respective spinning nozzles using a multi-hole spin nozzle pack.

5. The porous separator manufacturing method of claim 1, wherein the thermal compression temperature is set at a temperature between 170°

C. and 210°

C.

6. The porous separator manufacturing method of claim 1, wherein the heat-resistant polymer material is a heat-resistant polymer resin that is any one selected from the group consisting of:

aromatic polyester containing at least one of polyacrylonitrile (PAN), polyamide, polyimide, polyamide-imide, poly (meta-phenylene iso-phthalamide), polysulfone, polyether ketone, polyethylene terephthalate, polytrimethylene terephthalate, and polyethylene naphthalate;

polyphosphazenes containing at least one of polytetrafluoroethylene, polydiphenoxy phosphazene, poly {bis [2-(2-methoxyethoxy) phosphazene]};

polyurethane copolymer containing at least one of polyurethane and polyether urethane;

cellulose acetate, cellulose acetate butylrate, cellulose acetate propionate, polyester sulfone (PES), and polyether imide (PEI) and any one combination thereof.

7. The porous separator manufacturing method of claim 1, wherein the swelling polymer material is a swelling polymer resin that is any one selected from the group consisting of:

polyvinylidene fluoride (PVDF), poly (vinylidene fluoride-co-hexafluoropropylene), perfluoropolymer, polyvinyl chloride or polyvinylidene chloride, and copolymer thereof;

polyethylene glycol derivatives containing at least one of polyethylene glycol dialkylether and polyethylene glycol dialkyl ester;

polyoxide containing at least one of poly (oxymethylene-oligo-oxyethylene), polyethylene oxide and polypropylene oxide;

polyacrylonitrile copolymer containing at least one of polyvinyl acetate, poly (vinyl pyrrolidone-vinyl acetate), polystyrene, polystyrene acrylonitrile copolymer, and polyacrylonitrile methyl methacrylate copolymer; and

polymethyl methacrylate and polymethyl methacrylate copolymer, and any one combination thereof.

8. The porous separator manufacturing method of claim 1, wherein the mixed solution further comprises a two-component-system mixed solvent where a high boiling point solvent and a low boiling point solvent are mixed at a weight ratio ranging from 7:

3 to 9;

1.

9. A heat-resistant and high-strength ultrafine fibrous porous separator manufacturing method:

comprising the steps of;

air-electrospinning a mixed solution of a heat-resistant polymer material and a swelling polymer material, to thereby form a porous web made of a heat-resistant ultrafine fiber in which the heat-resistant polymer material and the swelling polymer material are consolidated in an ultrafine fibrous form;

performing drying to control a solvent and moisture that remain on the surface of the porous web, to thereby control the strength and porosity of the separator; and

performing thermal compression of the dried porous web so as to obtain the separator,

wherein an air pressure applied to a nozzle of a spin nozzle pack during the air-electrospinning is set in the range of 0.1 to 0.6 Mpa.

10. The porous separator manufacturing method of claim 9, wherein the mixed solution comprises 50-70 wt % of the heat-resistant polymer and 30-50 wt % of the swelling polymer material.

11. The porous separator manufacturing method of claim 9, wherein the air-electrospinning is performed by an independent air spray that takes place for respective spinning nozzles using a multi-hole spin nozzle pack.

12. The porous separator manufacturing method of claim 9, wherein the thermal compression temperature is set at a temperature between 170°

C. and 210°

C.

13. The porous separator manufacturing method of claim 9, wherein the mixed solution further comprises a two-component-system mixed solvent where a high boiling point solvent and a low boiling point solvent are mixed at a weight ratio ranging from 7:

3 to 9;

1.

14. A heat-resistant and high-strength ultrafine fibrous porous separator manufacturing method:

comprising the steps of;

air-electrospinning a mixed solution of a heat-resistant polymer material and a swelling polymer material, to thereby form a porous web made of a heat-resistant ultrafine fiber in which the heat-resistant polymer material and the swelling polymer material are consolidated in an ultrafine fibrous form;

performing drying to control a solvent and moisture that remain on the surface of the porous web, to thereby control the strength and porosity of the separator; and

performing thermal compression of the dried porous web so as to obtain the separator,

wherein the air-electrospinning is performed by an independent air spray that takes place for respective spinning nozzles using a multi-hole spin nozzle pack.

15. The porous separator manufacturing method of claim 14, wherein the mixed solution comprises 5070 wt % of the heat-resistant polymer and 30-50 wt % of the swelling polymer material.

16. The porous separator manufacturing method of claim 14, wherein the thermal compression temperature is set at a temperature between 170°

C. and 210°

C.

17. The porous separator manufacturing method of claim 14, wherein the mixed solution further comprises a two-component-system mixed solvent where a high boiling point solvent and a low boiling point solvent are mixed at a weight ratio ranging from 7:

3 to 9;

1.