Separator with organic/inorganic porous coating layer for electrochemical device, and electrochemical device including same
A separator for an electrochemical device, in which the separator includes a separator substrate and an organic-inorganic composite porous coating layer on at least one surface of the separator substrate. The separator substrate is a porous film including a polyolefin-containing polymer. The organic-inorganic composite porous coating layer includes a polymer resin particles and inorganic particles, in which each particle of the polymer resin particles includes a polyvinylidene fluoride (PVDF)-containing polymer and an acrylic polymer, and the PVDF-containing polymer has a Hansen solubility parameter (HSP) value of 13 or less and 1 or more.
1 . A separator for an electrochemical device, comprising:
a separator substrate; and
an organic-inorganic composite porous coating layer on at least one surface of the separator substrate,
wherein the separator substrate is a porous film comprising a polyolefin-containing polymer,
wherein the organic-inorganic composite porous coating layer comprises polymer resin particles and inorganic particles, and
wherein each particle of the polymer resin particles is a blend comprising a polyvinylidene fluoride (PVDF)-containing polymer and an acrylic polymer,
wherein the PVDF-containing polymer comprises a copolymer of vinylidene fluoride and a co-monomer as a polymerization unit,
wherein the co-monomer is present in an amount ranging from 1 wt % to 20 wt % with respect to 100 wt % of the PVDF-containing polymer, and
wherein the PVDF-containing polymer is present in the polymer resin particle in an amount the range of 50 wt % to 80 wt % relative to 100 wt % of the blend,
a wet adhesion with the electrode of 10 gf/20 mm or more.
2 . The separator of claim 1 , wherein the co-monomer is at least one selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, trifluoroethylene, chlorofluoroethylene, 1,2 difluoroethylene, perfluoro(methylvinyl)ether, perfluoro(ethylvinyl)ether, perfluoro(propylvinyl)ether, durfluoro(1,3 dioxole), perfluoro (2,2-dimethyl-1,3-dioxole), trichloroethylene, and vinylfluoride.
3 . The separator of claim 1 , wherein the co-monomer is present in an amount ranging from 5 wt % to 15 wt % with respect to 100 wt % of the PVDF-containing polymer.
4 . The separator of claim 1 , wherein the co-monomer is present in an amount ranging from 12 wt % to 20 wt % with respect to 100 wt % of the PVDF-containing polymer.
5 . The separator of claim 1 , wherein the co-monomer is present in an amount ranging from 15 wt % to 20 wt % with respect to 100 wt % of the PVDF-containing polymer.
6 . The separator of claim 1 , wherein the acrylic polymer is present in the polymer resin particle in an amount the range of 20 wt % to 50 wt % relative to 100 wt % of the blend.
7 . The separator of claim 1 , wherein the PVDF-containing polymer is present in the polymer resin particle in an amount the range of 50 wt % to 70 wt % relative to 100 wt % of the blend, and
wherein the acrylic polymer is present in the polymer resin particle in an amount the range of 30 wt % to 50 wt % relative to 100 wt % of the blend.
8 . An electrochemical device, comprising:
an anode,
a cathode,
an electrolyte, and
the separator of claim 1 ,
wherein the separator is interposed between the anode and the cathode, and
wherein a Hansen solubility parameter (HSP) value of the electrolyte is 14 or more and 35 or less.
9 . The separator of claim 1 , wherein the separator has a dry adhesion with an electrode of 10 gf/25 mm or more.
10 . The separator of claim 1 , wherein the acrylic polymer comprises styrene-butyl acrylate.
11 . The separator of claim 1 , wherein the separator has a dry adhesion with an electrode in a range of 30 gf/25 mm to 45 gf/25 mm and a wet adhesion with the electrode in a range of 12 gf/25 mm to 25 gf/25 mm.