Electrochemical device using multicomponent composite membrane film

• US 20030104273A1
• Filed: 10/22/2002
• Published: 06/05/2003
• Est. Priority Date: 03/05/2001
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation), Toray Industries Incorporated
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Ahn, Soon-Ho, Lee, Seung-Jin, Lee, Sang-Young, Song, Heon-Sik, Park, Soon-Yong, Cho, Jin-Yeon, Yong, Hyun-Hang, Lee, Hyang-Mok, Ahn, Byeong-In, Lee, Hyung-Keun, Kyung, You-jin
• Granted Patent: US 7,014,948 B2
• Time in Patent Office: Days
• US Class Current: 429/144
• CPC Class Codes: B01D 2325/04 Characteristic thickness
• CPC Class Codes: B01D 2325/26 Electrical properties
• CPC Class Codes: B01D 67/0013 Casting processes
• CPC Class Codes: B01D 67/0027 by stretching
• CPC Class Codes: B01D 67/0083 Thermal after-treatment
• CPC Class Codes: B01D 67/009 with wave-energy, particle-radiation or plasma
• CPC Class Codes: B01D 69/12 Composite membranes; Ultra-thin membranes
• CPC Class Codes: B01D 69/1213 Laminated layers
• CPC Class Codes: B01D 69/1216 Three or more layers
• 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 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 50/417 Polyolefins
• CPC Class Codes: H01M 50/42 Acrylic resins
• CPC Class Codes: H01M 50/423 Polyamide resins
• CPC Class Codes: H01M 50/426 Fluorocarbon polymers
• CPC Class Codes: H01M 50/491 Porosity
• 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

The present invention provides a electrochemical element, wherein a multi-component composite film comprising a) polymer support layer film and b) a porous gellable polymer layer which is formed on either or both sides of the support layer film of a), wherein the support layer film of a) and the gellable polymer layer of b) are unified with each other without an interface between them.

Claims

1. An electrochemical element comprising electrochemical cells which are multiply-stacked with a separator interposed film between each stacked cell, wherein said separator film comprises:

a) a polymeric support layer film; and

b) a porous gellable polymer layer which is formed on one side or both sides of the support layer,

wherein the support layer film of a) and the porous gellable polymer layer of b) are united with each other without an interface between them.

2. An electrochemical element comprising electrochemical cells which are multiply-stacked, wherein

a) said electrochemical cells are formed by stacking:

i) full cells having a positive electrode, a separator layer, and an negative electrode sequentially as a basic unit;

or

ii) {circle over (1)} bicells having a positive electrode, a separator layer, an negative electrode, another separator layer, and another positive electrode sequentially as a basic unit or

{circle over (2)} bicells having an negative electrode, a separator layer, a positive electrode, another separator layer, and another negative electrode sequentially as a basic unit; and

iii) a separator film interposed between each stacked cell;

b) each of said separator film, said separator layer, or both comprises;

i) a polymer support layer film and

ii) a porous gellable polymer layer which is formed on one side or both sides of the support layer film,

wherein said support layer film of i) and the porous gellable polymer layer of ii) are united with each other without an interface between them.

3. The electrochemical element according to claim 2, wherein a material of the polymeric support layer film of b) i) is at least one selected from the group consisting of high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, high crystalline polypropylene, polyethylene-propylene copolymer, polyethylene-butylene copolymer, polyethylene-hexene copolymer, polyethylene-octene copolymer, polystyrene-butylene-styrene copolymer, polystyrene-ethylene-butylene-styrene copolymer, polystyrene, polyphenylene oxide, polysulfone, polycarbonate, polyester, polyamide, polyurethane, polyacrylate, polyvinylidene chloride, polyvinylidene fluoride, polysiloxane, polyolefin ionomer, polymethyl pentene, hydrogenated oligocyclopentadiene (HOCP), and a copolymer thereof or a derivative thereof.

4. The electrochemical element according to claim 2, wherein a material of the gellable polymer layer of b) ii) is at least one selected from the group consisting of polyvinylidene fluoride, polyvinylidene fluoride-chlorotrifluoroethylene copolymer, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, polypropylene oxide, polybutylene oxide, polyurethane, polyacrylonitrile, polyacrylate, polymethyl methacrylate, polyacrylic acid, polyamide, polyacrylamide, polyvinyl acetate, polyvinylpyrrolidone, polytetraethylene glycol diacrylate, polysulfone, polyphenylene oxide, polycarbonate, polyester, polyvinylidene chloride polysiloxane, polyolefin ionomer, and a copolymer thereof or a derivative thereof.

5. The electrochemical element according to claim 2, wherein the gellable polymer layer comprises at least one lithium salt selected from the group consisting of LiSCN, LiClO₄, LiCF₃SO₃, LiAsF₆, LiN(CF₃SO₂)₂, and LiBF₄.

6. The electrochemical element according to claim 2, wherein the gellable polymer layer comprises at least one porous inorganic particle selected from the group consisting of SiO₂, TiO₂, Al₂O₃, MgO, and B₂O₃.

7. The electrochemical element according to claim 2, wherein a pore size of the support layer film of b) i) ranges from 0.001 to 10 μ

m, and its thickness ranges from 1 to 50 μ

m; and

a pore size of the porous gellable polymer layer of b) is at most 10 μ

m, and its thickness ranges from 0.01 to 25 μ

m.

8. The electrochemical element according to claim 2, wherein the multi-component composite film of b) is prepared by the steps of:

i) providing a polymeric support layer film;

ii) dissolving a gellable polymer in a solvent in order to prepare a gellable polymer solution;

iii) forming a gellable polymer layer on one side or both sides of the support layer film of i) by coating the support layer film with the gellable polymer solution of ii) in order to prepare a multiple layer; and

iv) stretching and heat-setting the multiple layer of iii).

9. The electrochemical element according to claim 8, wherein the high-temperature-stretching is performed after low-temperature-stretching of the multiple layer in the stretching process of iv).

10. The electrochemical element according to claim 8, wherein the heat-setting of iv) is performed under the condition of tension at 50°

C. or at most a temperature of the polymer melting point of the gellable polymer layer, for 10 seconds to an hour.

11. The electrochemical element according to claim 8, wherein the support layer film of i) is prepared by injecting the polymer into an extruder equipped with a T-die or a tubular die in order to extrude the polymer, and annealing it in a dry oven at from room temperature to a polymer melting point of the support layer at most.

12. The electrochemical element according to claim 8, wherein the solvent of ii) is at least one selected from the group consisting of 1-methyl-2-pyrrolidone (NMP), acetone, ethanol, n-propanol, n-butanol, n-hexane, cyclohexanol, acetic acid, ethyl acetate, diethyl ether, dimethyl formamide (DMF), dimethylacetamide (DMAc), dioxane, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), cyclohexane, benzene, toluene, xylene, water, and a derivative thereof.