Complex separator for electrochemical element, comprising bonding layer, and electrochemical element comprising same

Patent metadata

Field	Value
Publication number	US-2018123106-A1
Application number	US-201615569666-A
Country	US
Kind code	A1
Filing date	Aug 25, 2016
Priority date	Aug 25, 2015
Publication date	May 3, 2018
Grant date	—

Abstract

The present disclosure relates to a composite separator for an electrochemical element and the electrochemical element including the same. More specifically, the present disclosure relates to a separator with excellent durability and improved formation of a bonding layer of a thin film and improved bonding force with an electrode, and a method for manufacturing the same. Further, the present disclosure pertains to an electrochemical element comprising the aforementioned separator.

First claim

1 . A composite separator for electrochemical element, the separator comprising:
a porous polymeric material; and a porous coating layer formed on at least one side surface of the porous polymeric material, wherein the composite separator includes an electrode bonding layer formed on both surfaces or on at least one surface of outermost surfaces thereof, the porous coating layer includes inorganic particles and binder resin, an entirety or portion of a surface of the inorganic particles being coated with the binder resin, and thus the particles are laminated by point binding and/or plane binding between the inorganic particles and stratified, the porous coating layer has a porous structure formed by interstitial volume between the inorganic particles, and the electrode bonding layer includes a particulate polymer having adhesive characteristics, and glass transition temperature of the particulate polymer is −110° C. to 0° C.

2 . The composite separator of claim 1 , wherein a melting temperature of the particulate polymer is 20° C. to 150° C.

3 . The composite separator claim 1 , wherein the particle polymer includes a homopolymer of vinylidene fluoride monomer and/or a copolymer of vinylidene fluoride monomer and a co-monomer.

4 . The composite separator of claim 3 , wherein the copolymer is a copolymer resin of (a) vinylidene fluoride monomer and (b) one or more co-monomers selected from a group consisting of vinyl fluoride; trifluoroethylene (VF3); chlorotrifluoroethylene (CTFE); 1,2-difluoroethylene; tetrafluoroethylene (TFE); hexafluoropropylene (HFP); perfluoro(alkyl vinyl)ether such as perfluoro(methyl vinyl)ether (PMVE), perfluoro(ethyl vinyl)ether (PEVE) and perfluoro(propyl vinyl)ether (PPVE); perfluoro(1,3-dioxole); and perfluoro(2,2-dimethyl-1,3-dioxole) (PDD).

5 . The composite separator of claim 3 , wherein vinylidene fluoride copolymer comprises vinylidene fluoride monomer in the range of 70 parts by weight to 97 parts by weight with a weight ratio.

6 . The composite separator of claim 1 , wherein the bonding layer comprises the particulate polymer including methacrylate polymer.

7 . The composite separator of claim 1 , wherein the binder resin is an organic solvent-soluble binder.

8 . The composite separator of claim 1 , wherein the inorganic particle does not occur oxidation and/or reduction reaction at an operating voltage range of 0 to 5 V(Li/Li + ) of the electrochemical element.

9 . The composite separator of claim 8 , wherein the inorganic particle includes the inorganic particle having ion transfer capabilities and/or a high dielectricity inorganic particle having a dielectric constant of 5 or above.

10 . The composite separator of claim 7 , wherein the binder resin is prepared from an organic solvent as a solvent, and the particulate polymer is prepared from a water-borne solvent as a disperse medium.

11 . A method for manufacturing a composite separator for electrochemical element according to claim 1 , the method comprising:
applying a slurry including inorganic particles and binder resin of an organic solvent to a porous material and drying it to form a porous coating layer; and applying a composition for forming an electrode bonding layer containing a particulate polymer on the porous coating layer and drying it to form a bonding layer.

12 . The method of claim 11 , wherein the organic solvent is one or two or more types of mixture selected from aliphatic hydrocarbons, aromatic hydrocarbons, ketones, chlorine-based aliphatic hydrocarbons, esters, ethers, alcohols and amides.

13 . The method of claim 11 , wherein the composition for forming the electrode bonding layer has a particulate polymer prepared from emulsion or suspension dispersed in a water-borne solvent.

14 . The composite separator of claim 1 , wherein the electrode bonding layer is formed on an upper surface of the porous coating layer.

15 . The composite separator of claim 1 , wherein the electrode bonding layer has a coating amount of the particulate polymer of 0.05 g/m 2 to 5 g/m 2 .

Assignees

• Lg Chemical Ltd

Inventors

• Shin Jin-Young
• Kim Young-Deok
• Yoon Su-Jin

Classifications

• H01M50/461 Primary

  with adhesive layers between electrodes and separators · CPC title

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/414

  Synthetic resins, e.g. thermoplastics or thermosetting resins · CPC title

• H01M2/1686 Primary

  Electricity · mapped topic

• H01M2/145

  Electricity · mapped topic