JP2022089292A - Cell separator - Google Patents
Cell separator Download PDFInfo
- Publication number
- JP2022089292A JP2022089292A JP2020201584A JP2020201584A JP2022089292A JP 2022089292 A JP2022089292 A JP 2022089292A JP 2020201584 A JP2020201584 A JP 2020201584A JP 2020201584 A JP2020201584 A JP 2020201584A JP 2022089292 A JP2022089292 A JP 2022089292A
- Authority
- JP
- Japan
- Prior art keywords
- heat
- porous layer
- resistant porous
- battery
- battery separator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229920000098 polyolefin Polymers 0.000 claims abstract description 41
- 239000012982 microporous membrane Substances 0.000 claims abstract 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 claims description 50
- 239000010954 inorganic particle Substances 0.000 claims description 21
- 239000002245 particle Substances 0.000 claims description 17
- 239000012528 membrane Substances 0.000 description 30
- 238000000034 method Methods 0.000 description 26
- 239000011148 porous material Substances 0.000 description 18
- 239000000203 mixture Substances 0.000 description 17
- 229920005989 resin Polymers 0.000 description 16
- 239000011347 resin Substances 0.000 description 16
- -1 polyethylene Polymers 0.000 description 15
- 239000007788 liquid Substances 0.000 description 12
- 238000012360 testing method Methods 0.000 description 12
- 239000011248 coating agent Substances 0.000 description 11
- 238000000576 coating method Methods 0.000 description 11
- 239000004698 Polyethylene Substances 0.000 description 10
- 230000035699 permeability Effects 0.000 description 10
- 229920000573 polyethylene Polymers 0.000 description 10
- 239000011324 bead Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- 229920002451 polyvinyl alcohol Polymers 0.000 description 9
- 229920003169 water-soluble polymer Polymers 0.000 description 8
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 7
- 239000004372 Polyvinyl alcohol Substances 0.000 description 7
- 239000006185 dispersion Substances 0.000 description 7
- 239000002612 dispersion medium Substances 0.000 description 7
- 229910001416 lithium ion Inorganic materials 0.000 description 7
- 229920002401 polyacrylamide Polymers 0.000 description 7
- 229920000178 Acrylic resin Polymers 0.000 description 6
- 239000004925 Acrylic resin Substances 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- 239000002390 adhesive tape Substances 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 239000008151 electrolyte solution Substances 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- IMROMDMJAWUWLK-UHFFFAOYSA-N Ethenol Chemical compound OC=C IMROMDMJAWUWLK-UHFFFAOYSA-N 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- 239000000654 additive Substances 0.000 description 4
- 239000011230 binding agent Substances 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 230000010220 ion permeability Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000005498 polishing Methods 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 3
- 230000000996 additive effect Effects 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 229920003086 cellulose ether Polymers 0.000 description 3
- 239000002270 dispersing agent Substances 0.000 description 3
- 229920001971 elastomer Polymers 0.000 description 3
- 229920001903 high density polyethylene Polymers 0.000 description 3
- 239000004700 high-density polyethylene Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 229920001684 low density polyethylene Polymers 0.000 description 3
- 239000004702 low-density polyethylene Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229920001179 medium density polyethylene Polymers 0.000 description 3
- 239000004701 medium-density polyethylene Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 229920005672 polyolefin resin Polymers 0.000 description 3
- 239000005060 rubber Substances 0.000 description 3
- 238000004062 sedimentation Methods 0.000 description 3
- 230000003068 static effect Effects 0.000 description 3
- 229920000785 ultra high molecular weight polyethylene Polymers 0.000 description 3
- LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 description 2
- KWKAKUADMBZCLK-UHFFFAOYSA-N 1-octene Chemical compound CCCCCCC=C KWKAKUADMBZCLK-UHFFFAOYSA-N 0.000 description 2
- WSSSPWUEQFSQQG-UHFFFAOYSA-N 4-methyl-1-pentene Chemical compound CC(C)CC=C WSSSPWUEQFSQQG-UHFFFAOYSA-N 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 2
- 239000004594 Masterbatch (MB) Substances 0.000 description 2
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 2
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 239000004699 Ultra-high molecular weight polyethylene Substances 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 239000004480 active ingredient Substances 0.000 description 2
- 239000011149 active material Substances 0.000 description 2
- 239000003463 adsorbent Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 2
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Chemical compound [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 2
- OJIJEKBXJYRIBZ-UHFFFAOYSA-N cadmium nickel Chemical compound [Ni].[Cd] OJIJEKBXJYRIBZ-UHFFFAOYSA-N 0.000 description 2
- 239000000292 calcium oxide Substances 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 239000001768 carboxy methyl cellulose Substances 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 238000002788 crimping Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000010292 electrical insulation Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- YWAKXRMUMFPDSH-UHFFFAOYSA-N pentene Chemical compound CCCC=C YWAKXRMUMFPDSH-UHFFFAOYSA-N 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 230000001376 precipitating effect Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Chemical compound [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 239000000080 wetting agent Substances 0.000 description 2
- 239000004711 α-olefin Substances 0.000 description 2
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 description 1
- 229920002126 Acrylic acid copolymer Polymers 0.000 description 1
- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- 235000013162 Cocos nucifera Nutrition 0.000 description 1
- 244000060011 Cocos nucifera Species 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 1
- 241000984084 Helianthemum nummularium subsp. grandiflorum Species 0.000 description 1
- 229910017569 La2(CO3)3 Inorganic materials 0.000 description 1
- 229910007857 Li-Al Inorganic materials 0.000 description 1
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 229910008447 Li—Al Inorganic materials 0.000 description 1
- 229910003023 Mg-Al Inorganic materials 0.000 description 1
- 229910019089 Mg-Fe Inorganic materials 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 239000002174 Styrene-butadiene Substances 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical compound [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- CUPCBVUMRUSXIU-UHFFFAOYSA-N [Fe].OOO Chemical compound [Fe].OOO CUPCBVUMRUSXIU-UHFFFAOYSA-N 0.000 description 1
- JDZCKJOXGCMJGS-UHFFFAOYSA-N [Li].[S] Chemical compound [Li].[S] JDZCKJOXGCMJGS-UHFFFAOYSA-N 0.000 description 1
- XHCLAFWTIXFWPH-UHFFFAOYSA-N [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] XHCLAFWTIXFWPH-UHFFFAOYSA-N 0.000 description 1
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical compound [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 description 1
- HPTYUNKZVDYXLP-UHFFFAOYSA-N aluminum;trihydroxy(trihydroxysilyloxy)silane;hydrate Chemical compound O.[Al].[Al].O[Si](O)(O)O[Si](O)(O)O HPTYUNKZVDYXLP-UHFFFAOYSA-N 0.000 description 1
- 229910001588 amesite Inorganic materials 0.000 description 1
- 125000003368 amide group Chemical group 0.000 description 1
- 125000003277 amino group Chemical group 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 229910052586 apatite Inorganic materials 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 239000010425 asbestos Substances 0.000 description 1
- WDIHJSXYQDMJHN-UHFFFAOYSA-L barium chloride Chemical compound [Cl-].[Cl-].[Ba+2] WDIHJSXYQDMJHN-UHFFFAOYSA-L 0.000 description 1
- 229910001626 barium chloride Inorganic materials 0.000 description 1
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 1
- 239000000440 bentonite Substances 0.000 description 1
- 229910000278 bentonite Inorganic materials 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 229910000416 bismuth oxide Inorganic materials 0.000 description 1
- 229910001593 boehmite Inorganic materials 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- MTAZNLWOLGHBHU-UHFFFAOYSA-N butadiene-styrene rubber Chemical compound C=CC=C.C=CC1=CC=CC=C1 MTAZNLWOLGHBHU-UHFFFAOYSA-N 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000000378 calcium silicate Substances 0.000 description 1
- 229910052918 calcium silicate Inorganic materials 0.000 description 1
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- MYWGVEGHKGKUMM-UHFFFAOYSA-N carbonic acid;ethene Chemical compound C=C.C=C.OC(O)=O MYWGVEGHKGKUMM-UHFFFAOYSA-N 0.000 description 1
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 229910000420 cerium oxide Inorganic materials 0.000 description 1
- GHLITDDQOMIBFS-UHFFFAOYSA-H cerium(3+);tricarbonate Chemical compound [Ce+3].[Ce+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O GHLITDDQOMIBFS-UHFFFAOYSA-H 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- OPQARKPSCNTWTJ-UHFFFAOYSA-L copper(ii) acetate Chemical compound [Cu+2].CC([O-])=O.CC([O-])=O OPQARKPSCNTWTJ-UHFFFAOYSA-L 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- GUJOJGAPFQRJSV-UHFFFAOYSA-N dialuminum;dioxosilane;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3].O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O GUJOJGAPFQRJSV-UHFFFAOYSA-N 0.000 description 1
- GDVKFRBCXAPAQJ-UHFFFAOYSA-A dialuminum;hexamagnesium;carbonate;hexadecahydroxide Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Al+3].[Al+3].[O-]C([O-])=O GDVKFRBCXAPAQJ-UHFFFAOYSA-A 0.000 description 1
- TYIXMATWDRGMPF-UHFFFAOYSA-N dibismuth;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Bi+3].[Bi+3] TYIXMATWDRGMPF-UHFFFAOYSA-N 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 229910021485 fumed silica Inorganic materials 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 239000010440 gypsum Substances 0.000 description 1
- 229910052602 gypsum Inorganic materials 0.000 description 1
- 229910052621 halloysite Inorganic materials 0.000 description 1
- 125000005843 halogen group Chemical group 0.000 description 1
- 229910052595 hematite Inorganic materials 0.000 description 1
- 239000011019 hematite Substances 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 229910001701 hydrotalcite Inorganic materials 0.000 description 1
- 229960001545 hydrotalcite Drugs 0.000 description 1
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 description 1
- 229910021519 iron(III) oxide-hydroxide Inorganic materials 0.000 description 1
- 229910052622 kaolinite Inorganic materials 0.000 description 1
- CYPPCCJJKNISFK-UHFFFAOYSA-J kaolinite Chemical compound [OH-].[OH-].[OH-].[OH-].[Al+3].[Al+3].[O-][Si](=O)O[Si]([O-])=O CYPPCCJJKNISFK-UHFFFAOYSA-J 0.000 description 1
- NZPIUJUFIFZSPW-UHFFFAOYSA-H lanthanum carbonate Chemical compound [La+3].[La+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O NZPIUJUFIFZSPW-UHFFFAOYSA-H 0.000 description 1
- 229960001633 lanthanum carbonate Drugs 0.000 description 1
- 239000004816 latex Substances 0.000 description 1
- 229920000126 latex Polymers 0.000 description 1
- 229910000464 lead oxide Inorganic materials 0.000 description 1
- PIJPYDMVFNTHIP-UHFFFAOYSA-L lead sulfate Chemical compound [PbH4+2].[O-]S([O-])(=O)=O PIJPYDMVFNTHIP-UHFFFAOYSA-L 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 description 1
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 1
- 239000000391 magnesium silicate Substances 0.000 description 1
- 229910052919 magnesium silicate Inorganic materials 0.000 description 1
- 235000019792 magnesium silicate Nutrition 0.000 description 1
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 1
- 235000019341 magnesium sulphate Nutrition 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 238000010907 mechanical stirring Methods 0.000 description 1
- 239000012567 medical material Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 239000012968 metallocene catalyst Substances 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 229910052901 montmorillonite Inorganic materials 0.000 description 1
- TVMXDCGIABBOFY-UHFFFAOYSA-N n-Octanol Natural products CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 description 1
- QELJHCBNGDEXLD-UHFFFAOYSA-N nickel zinc Chemical compound [Ni].[Zn] QELJHCBNGDEXLD-UHFFFAOYSA-N 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000011255 nonaqueous electrolyte Substances 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 1
- YEXPOXQUZXUXJW-UHFFFAOYSA-N oxolead Chemical compound [Pb]=O YEXPOXQUZXUXJW-UHFFFAOYSA-N 0.000 description 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 1
- VSIIXMUUUJUKCM-UHFFFAOYSA-D pentacalcium;fluoride;triphosphate Chemical compound [F-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O VSIIXMUUUJUKCM-UHFFFAOYSA-D 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 125000002467 phosphate group Chemical group [H]OP(=O)(O[H])O[*] 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 239000002685 polymerization catalyst Substances 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- CHWRSCGUEQEHOH-UHFFFAOYSA-N potassium oxide Chemical compound [O-2].[K+].[K+] CHWRSCGUEQEHOH-UHFFFAOYSA-N 0.000 description 1
- 229910001950 potassium oxide Inorganic materials 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 229910052895 riebeckite Inorganic materials 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 150000004760 silicates Chemical class 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- BSWGGJHLVUUXTL-UHFFFAOYSA-N silver zinc Chemical compound [Zn].[Ag] BSWGGJHLVUUXTL-UHFFFAOYSA-N 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 description 1
- 229920001027 sodium carboxymethylcellulose Polymers 0.000 description 1
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 1
- 229910001948 sodium oxide Inorganic materials 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000011115 styrene butadiene Substances 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 125000000542 sulfonic acid group Chemical group 0.000 description 1
- 125000000472 sulfonyl group Chemical group *S(*)(=O)=O 0.000 description 1
- 238000010189 synthetic method Methods 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- JUWGUJSXVOBPHP-UHFFFAOYSA-B titanium(4+);tetraphosphate Chemical compound [Ti+4].[Ti+4].[Ti+4].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O JUWGUJSXVOBPHP-UHFFFAOYSA-B 0.000 description 1
- 150000004684 trihydrates Chemical class 0.000 description 1
- BIKXLKXABVUSMH-UHFFFAOYSA-N trizinc;diborate Chemical compound [Zn+2].[Zn+2].[Zn+2].[O-]B([O-])[O-].[O-]B([O-])[O-] BIKXLKXABVUSMH-UHFFFAOYSA-N 0.000 description 1
- 238000000108 ultra-filtration Methods 0.000 description 1
- 238000001132 ultrasonic dispersion Methods 0.000 description 1
- 229910001935 vanadium oxide Inorganic materials 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
- 229910001928 zirconium oxide Inorganic materials 0.000 description 1
- 229910000166 zirconium phosphate Inorganic materials 0.000 description 1
- LEHFSLREWWMLPU-UHFFFAOYSA-B zirconium(4+);tetraphosphate Chemical compound [Zr+4].[Zr+4].[Zr+4].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O LEHFSLREWWMLPU-UHFFFAOYSA-B 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Cell Separators (AREA)
Abstract
Description
本発明は、ポリオレフィン多孔質膜の少なくとも片面に耐熱性多孔層を有する電池用セパレータに関するものである。 The present invention relates to a battery separator having a heat resistant porous layer on at least one side of a porous polyolefin membrane.
熱可塑性樹脂多孔質膜は、物質の分離や選択透過及び隔離材等として広く用いられている。例えば、リチウムイオン二次電池、ニッケル－水素電池、ニッケル－カドミウム電池、及びポリマー電池等に用いる電池用セパレータや、電気二重層コンデンサ用セパレータ、逆浸透濾過膜、限外濾過膜、及び精密濾過膜等の各種フィルター、透湿防水衣料、及び
医療用材料等である。
The thermoplastic resin porous membrane is widely used as a substance separation, selective permeation, and a separating material. For example, battery separators used for lithium ion secondary batteries, nickel-hydrogen batteries, nickel-cadmium batteries, polymer batteries, etc., separators for electric double layer capacitors, back-penetration filtration membranes, ultrafiltration membranes, and precision filtration membranes. Various filters such as, moisture permeable and waterproof clothing, medical materials, etc.
特に、リチウムイオン二次電池用セパレータとしては、電解液含浸によりイオン透過性を有し、電気絶縁性、耐電解液性及び耐酸化性に優れ、電池異常昇温時に１２０～１５０℃
程度の温度において電流を遮断し、過度の昇温を抑制する孔閉塞効果をも備えているポリ
オレフィン多孔質膜が好適に使用されている。
In particular, the separator for a lithium ion secondary battery has ion permeability due to impregnation with an electrolytic solution, is excellent in electrical insulation, electrolytic solution resistance and oxidation resistance, and has an abnormal temperature rise of 120 to 150 ° C.
A polyolefin porous membrane having a pore closing effect that cuts off a current at a certain temperature and suppresses an excessive temperature rise is preferably used.
しかしながら、何らかの原因で孔閉塞後も昇温が続く場合、ポリオレフィン多孔質膜は
破膜を生じることがある。この現象はポリオレフィンを用いた場合に限定される現象では
なく、その多孔質膜を構成する樹脂の融点以上では避けることができない。
However, if the temperature rises even after the pores are closed for some reason, the porous polyolefin membrane may cause film rupture. This phenomenon is not limited to the case where polyolefin is used, and cannot be avoided above the melting point of the resin constituting the porous film.
これに対し、ポリオレフィン多孔質膜に対して、無機粒子とバインダー樹脂を主として
構成する耐熱性多孔層を被覆した耐熱性セパレータが採用されている。この耐熱性セパレータを用いることで、ポリオレフィン多孔質膜の昇温による収縮が耐熱性多孔層により抑
制されている。
このようなセパレータにおいて、無機粒子と、ポリビニルアルコール（ＰＶＡ）と、ホウ酸および／またはＰＶＡ架橋性を有する有機金属化合物と、カルボキシル基および／またはスルホン酸基を有する水溶性化合物から形成された耐熱層を備えるセパレータ（特許文献１）、アルミナ水和物と、バインダーポリマーの水性分散液と、水溶液性分散剤を含む塗工液を不織布に塗工、乾燥して成るリチウムイオン電池用セパレータ（特許文献２）が提案されているが、耐熱性多孔層が薄い場合でも、耐熱収縮性に優れ、かつ耐熱性多孔層の脱落が少ないセパレータではなかった。
On the other hand, a heat-resistant separator in which a heat-resistant porous layer mainly composed of inorganic particles and a binder resin is coated on the porous polyolefin film is adopted. By using this heat-resistant separator, shrinkage due to temperature rise of the polyolefin porous membrane is suppressed by the heat-resistant porous layer.
In such a separator, heat resistance formed from inorganic particles, polyvinyl alcohol (PVA), boric acid and / or an organic metal compound having PVA crosslinkability, and a water-soluble compound having a carboxyl group and / or a sulfonic acid group. Separator for lithium ion battery (Patent Document 1) consisting of a separator having a layer (Patent Document 1), an alumina hydrate, an aqueous dispersion of a binder polymer, and a coating liquid containing an aqueous dispersant coated on a non-woven fabric and dried. Although Document 2) has been proposed, it is not a separator having excellent heat shrinkage and less dropout of the heat-resistant porous layer even when the heat-resistant porous layer is thin.
本発明の課題は、耐熱性多孔層が薄い場合でも、耐熱収縮性に優れ、かつ耐熱性多孔層の脱落が少ないセパレータセパレータの提供である。 An object of the present invention is to provide a separator separator having excellent heat-resistant shrinkage and less dropout of the heat-resistant porous layer even when the heat-resistant porous layer is thin.
本発明者らは、従来の技術を鑑み、鋭意検討し、ポリオレフィン多孔質膜の少なくとも片面に耐熱性多孔層を有する電池用セパレータであって、１５０℃/１ｈ熱収縮率が５％以下であり、かつ耐熱性多孔層の脱落量が０．６ｍｇ以下であることを特徴とする電池用セパレータにより、本課題を解決することを見出した。
更に好ましい様態は、
（１）前記耐熱性多孔層はＢＥＴ比表面積が６．５ｍ２／ｇ以上、３０ｍ２／ｇ以下である沈降性硫酸バリウム粒子を含むこと
（２）耐熱性多孔層の９２重量％以上、９９重量％以下が無機粒子であること
（３）前記耐熱性多孔層の１８０°剥離強度が３５０Ｎ／ｍ以上であること
（４）前記耐熱性多孔層の厚さが０．５μｍ以上、４μｍ以下であることを特徴とする電池用セパレータである。
The present inventors have studied diligently in view of the prior art, and are battery separators having a heat-resistant porous layer on at least one side of the polyolefin porous film, and have a heat shrinkage rate of 150 ° C./1 h of 5% or less. Moreover, it has been found that this problem can be solved by a battery separator characterized in that the amount of the heat-resistant porous layer dropped off is 0.6 mg or less.
A more preferable mode is
(1) The heat-resistant porous layer contains precipitated barium sulfate particles having a BET specific surface area of 6.5 m 2 / g or more and 30 m 2 / g or less (2) 92% by weight or more of the heat-resistant porous layer, 99. The weight% or less is inorganic particles (3) The 180 ° peeling strength of the heat-resistant porous layer is 350 N / m or more (4) The thickness of the heat-resistant porous layer is 0.5 μm or more and 4 μm or less. It is a battery separator characterized by being present.
本発明のポリオレフィン多孔質膜の少なくとも片面に耐熱性多孔層を有する電池用セパレータは、耐熱収縮性に優れ、耐熱性多孔層の脱落が少ないため、電池の安全性や歩留まりが向上する。 The battery separator having a heat-resistant porous layer on at least one surface of the polyolefin porous film of the present invention has excellent heat-resistant shrinkage and the heat-resistant porous layer is less likely to fall off, so that the safety and yield of the battery are improved.
以下、本発明の実施形態について詳細に説明する。なお、本発明は、以下に説明する実
施形態に限定されるものではない。
［ポリオレフィン多孔質膜］
本発明の実施形態におけるポリオレフィン多孔質膜の厚さは、電池用セパレータの機能を有する限りにおいて特に制限されるものではないが、２５μｍ以下が好ましい。より好ましくは３μｍ以上、２０μｍ以下であり、さらに好ましくは５μｍ以上、１６μｍ以下である。ポリオレフィン多孔質膜の厚さが２５μｍ以下であると、実用的な膜強度と孔閉塞機能を両立させることが出来、電池ケースの単位容積当たりの面積が制約されず、電池の高容量化に適する。
Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the embodiments described below.
[Polyolefin Porous Membrane]
The thickness of the porous polyolefin membrane in the embodiment of the present invention is not particularly limited as long as it has the function of a battery separator, but is preferably 25 μm or less. It is more preferably 3 μm or more and 20 μm or less, and further preferably 5 μm or more and 16 μm or less. When the thickness of the porous polyolefin membrane is 25 μm or less, it is possible to achieve both practical membrane strength and pore closing function, the area per unit volume of the battery case is not restricted, and it is suitable for increasing the capacity of the battery. ..
ポリオレフィン多孔質膜の透気抵抗度は３０ｓｅｃ/１００ｍｌＡｉｒ以上、２００
ｓｅｃ/１００ｍｌＡｉｒ以下が好ましい。より好ましくは４０ｓｅｃ/１００ｍｌＡ
ｉｒ以上、１５０ｓｅｃ/１００ｍｌＡｉｒ以下であり、さらに好ましくは５０ｓｅｃ/
１００ｍｌＡｉｒ以上、１００ｓｅｃ/１００ｍｌＡｉｒ以下である。透気抵抗度が
３０ｓｅｃ/１００ｃｍｌＡｉｒ以上であると、十分な機械的強度と絶縁性が得られることで電池の充放電時に短絡が起こる可能性が低くなる。２００ｓｅｃ/１００ｍｌＡｉｒ以下であると、十分な電池の充放電特性、特にイオン透過性（充放電作動電圧）及び電池の寿命（電解液の保持量と密接に関係する）において十分であり、電池としての機能を十分に発揮することができる。
The air permeability resistance of the porous polyolefin membrane is 30 sec / 100 ml Air or more, 200.
It is preferably sec / 100 ml Air or less. More preferably 40 sec / 100 mlA
ir or more, 150 sec / 100 ml Air or less, more preferably 50 sec /
It is 100 ml Air or more and 100 sec / 100 ml Air or less. When the air permeation resistance is 30 sec / 100 cml Air or more, sufficient mechanical strength and insulation are obtained, and the possibility of a short circuit during charging / discharging of the battery is reduced. When it is 200 sec / 100 ml Air or less, it is sufficient in terms of sufficient battery charge / discharge characteristics, particularly ion permeability (charge / discharge operating voltage) and battery life (which is closely related to the amount of electrolytic solution retained), and is used as a battery. It can fully demonstrate its function.
ポリオレフィン多孔質膜の空孔率は２０％以上、７０％以下が好ましい。より好ましく
は３０％以上、６０％以下であり、さらに好ましくは５５％以下である。空孔率が２０％
以上、７０％以下であると、十分な電池の充放電特性、特にイオン透過性（充放電作動電
圧）及び電池の寿命（電解液の保持量と密接に関係する）において十分であり、電池としての機能を十分に発揮することができ、十分な機械的強度と絶縁性が得られることで充放
電時に短絡が起こる可能性が低くなる。
The porosity of the porous polyolefin membrane is preferably 20% or more and 70% or less. It is more preferably 30% or more, 60% or less, and further preferably 55% or less. Porosity is 20%
As described above, when it is 70% or less, it is sufficient in terms of sufficient battery charge / discharge characteristics, particularly ion permeability (charge / discharge operating voltage) and battery life (which is closely related to the holding amount of the electrolytic solution), and is sufficient as a battery. It is possible to fully exert the function of the above, and by obtaining sufficient mechanical strength and insulating property, the possibility of short circuit during charging / discharging is reduced.
ポリオレフィン多孔質膜の平均孔径は、孔閉塞性能に大きく影響を与えるため、０．０
１μｍ以上、１．０μｍ以下が好ましい。より好ましくは０．０２μｍ以上、０．５μｍ
以下であり、さらに好ましくは０．０３μｍ以上、０．３μｍ以下である。ポリオレフィ
ン多孔質膜の平均孔径が０．０１μｍ未満であると、耐熱性多孔層を積層した際に有機合
成成分による孔の目詰まりが発生し、透気抵抗度および電気抵抗度が悪化する。１μｍ以
上であると、耐熱性多孔層組成物による孔の目詰まりが発生し、透気抵抗度および電気抵
抗度が悪化する場合や微短絡の発生のため電池の安全性が低下する場合がある。
The average pore size of the polyolefin porous membrane has a large effect on the pore closing performance, so 0.0
It is preferably 1 μm or more and 1.0 μm or less. More preferably 0.02 μm or more, 0.5 μm
It is less than or equal to, and more preferably 0.03 μm or more and 0.3 μm or less. When the average pore diameter of the polyolefin porous membrane is less than 0.01 μm, the pores are clogged by the organic synthetic component when the heat-resistant porous layer is laminated, and the air permeation resistance and the electric resistance deteriorate. If it is 1 μm or more, the pores may be clogged by the heat-resistant porous layer composition, and the air permeation resistance and the electric resistance may be deteriorated, or the safety of the battery may be lowered due to the occurrence of a slight short circuit. ..
また、ポリオレフィン多孔質膜の平均孔径が０．０１μｍ以上、１．０μｍ以下である
と、組成物のアンカー効果により、ポリオレフィン多孔質膜に対する、十分な耐熱性多孔
層の密着強度が得られ、耐熱性多孔層を積層した際に透気抵抗度及び電気抵抗度が大幅に
悪化せず、かつ、孔閉塞現象の温度に対する応答が緩慢になることもなく、昇温速度による孔閉塞温度がより高温側にシフトすることも少ない。本発明で言う平均孔径とはＪＩＳ
Ｋ ３８３２：１９９０で規定されるバブルポイント法にて得た測定値である。
Further, when the average pore diameter of the porous polyolefin film is 0.01 μm or more and 1.0 μm or less, sufficient adhesion strength of the heat-resistant porous layer to the porous polyolefin film can be obtained due to the anchor effect of the composition, and heat resistance is obtained. When the porous porous layers are laminated, the air permeability resistance and electrical resistance do not deteriorate significantly, and the response to the temperature of the pore closing phenomenon does not slow down, and the pore closing temperature due to the temperature rise rate becomes higher. It rarely shifts to the side. The average pore diameter referred to in the present invention is JIS.
It is a measured value obtained by the bubble point method defined by K 3832: 1990.
ポリオレフィン多孔質膜を構成するポリオレフィン樹脂は特に制限されるものではない
が、ポリエチレンやポリプロピレンが好ましい。また、単一物又は２種以上の異なるポリ
オレフィン樹脂の混合物、例えばポリエチレンとポリプロピレンとの混合物であってもよいし、異なるオレフィンの共重合体であってもよい。電気絶縁性、及びイオン透過性等の
基本特性に加え、電池異常昇温時において、電流を遮断し、過度の昇温を抑制する孔閉塞
効果を具備しているからである。
The polyolefin resin constituting the polyolefin porous film is not particularly limited, but polyethylene or polypropylene is preferable. Further, it may be a single substance or a mixture of two or more different polyolefin resins, for example, a mixture of polyethylene and polypropylene, or a copolymer of different olefins. This is because, in addition to basic characteristics such as electrical insulation and ion permeability, it has a hole closing effect that cuts off the current and suppresses an excessive temperature rise when the battery temperature rises abnormally.
なかでもポリエチレンが優れた孔閉塞性能の観点から特に好ましい。以下、本発明で用
いるポリオレフィン樹脂としてポリエチレンを例に詳述するが、本発明の実施形態はこれ
に限定されるものではない。
Among them, polyethylene is particularly preferable from the viewpoint of excellent pore closing performance. Hereinafter, polyethylene will be described in detail as an example of the polyolefin resin used in the present invention, but the embodiments of the present invention are not limited thereto.
ポリエチレンとしては、例えば、超高分子量ポリエチレン、高密度ポリエチレン、中密
度ポリエチレン及び低密度ポリエチレン等が挙げられる。また重合触媒にも特に制限はなく、チーグラー・ナッタ系触媒やフィリップス系触媒やメタロセン系触媒等が挙げられる。これらのポリエチレンはエチレンの単独重合体のみならず、他のα－オレフィンを少量
含有する共重合体であってもよい。エチレン以外のα－オレフィンとしてはプロピレン、
１－ブテン、１－ペンテン、１－ヘキセン、４－メチル－１－ペンテン、１－オクテン、
（メタ）アクリル酸、（メタ）アクリル酸のエステル、スチレン等が好適である。
Examples of polyethylene include ultra-high molecular weight polyethylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene and the like. The polymerization catalyst is also not particularly limited, and examples thereof include Ziegler-Natta catalysts, Philips catalysts, and metallocene catalysts. These polyethylenes may be not only ethylene homopolymers but also copolymers containing a small amount of other α-olefins. As α-olefins other than ethylene, propylene,
1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene,
(Meta) acrylic acid, (meth) acrylic acid ester, styrene and the like are suitable.
ポリエチレンは単一物でもよいが、２種以上のポリエチレンからなる混合物であること
が好ましい。ポリエチレン混合物としては重量平均分子量（Ｍｗ）の異なる２種類以上の
超高分子量ポリエチレン同士の混合物、同様な高密度ポリエチレン、中密度ポリエチレン
及び低密度ポリエチレンの混合物を用いてもよいし、超高分子量ポリエチレン、高密度ポ
リエチレン、中密度ポリエチレン及び低密度ポリエチレンからなる群から選ばれる２種以
上ポリエチレンの混合物を用いてもよい。
The polyethylene may be a single material, but is preferably a mixture of two or more types of polyethylene. As the polyethylene mixture, a mixture of two or more types of ultra-high molecular weight polyethylenes having different weight average molecular weights (Mw), a similar mixture of high-density polyethylene, medium-density polyethylene and low-density polyethylene may be used, or ultra-high molecular weight polyethylene may be used. , A mixture of two or more polyethylenes selected from the group consisting of high density polyethylene, medium density polyethylene and low density polyethylene may be used.
ポリオレフィン多孔質膜は、充放電反応の異常時に孔が閉塞する機能を有することが必
要である。従って、構成する樹脂の融点（軟化点）は７０℃以上、１５０℃以下が好まし
い。より好ましくは８０℃以上、１４０℃以下、さらに好ましくは１００℃以上、１３０
℃以下である。構成する樹脂の融点が７０℃以上、１５０℃以下であると、正常使用時に
孔閉塞機能が発現してしまって電池が使用不可になることがなく、また、異常反応時に孔
閉塞機能が発現することで安全性を確保できる。
The porous polyolefin membrane needs to have a function of closing the pores when the charge / discharge reaction is abnormal. Therefore, the melting point (softening point) of the constituent resin is preferably 70 ° C. or higher and 150 ° C. or lower. More preferably 80 ° C or higher, 140 ° C or lower, further preferably 100 ° C or higher, 130
It is below ° C. When the melting point of the constituent resin is 70 ° C. or higher and 150 ° C. or lower, the pore closing function is not exhibited during normal use and the battery is not disabled, and the pore closing function is exhibited during an abnormal reaction. This can ensure safety.
［耐熱性多孔層］
本発明の耐熱性多孔層は、前記ポリオレフィン多孔質膜の少なくとも片面に耐熱性多孔層が設けられるものであり、無機粒子、水溶性高分子、添加剤を含有する。片面のみに設ける場合、耐熱性多孔層を形成する工程が少なく、生産コストを抑えることができ、両面に設ける場合、ポリオレフィン多孔質膜の熱による収縮を両面から抑制することで、より効果的に電池用セパレータの熱による収縮を低減することができる。
[Heat-resistant porous layer]
The heat-resistant porous layer of the present invention is provided with the heat-resistant porous layer on at least one surface of the polyolefin porous membrane, and contains inorganic particles, a water-soluble polymer, and an additive. When it is provided on only one side, there are few steps to form a heat-resistant porous layer, and the production cost can be suppressed. When it is provided on both sides, it is more effective by suppressing the shrinkage due to heat of the polyolefin porous membrane from both sides. It is possible to reduce the shrinkage of the battery separator due to heat.
［無機粒子］
本発明の無機粒子は、電気化学的に安定であれば特に材質を制限するものではない。具
体的には、酸化ナトリウム、酸化カリウム、酸化マグネシウム、酸化カルシウム、酸化バ
リウム、酸化ランタン、酸化セリウム、酸化ストロンチウム、酸化バナジウム、ＳｉＯ２
－ＭｇＯ（ケイ酸マグネシウム）、ＳｉＯ２－ＣａＯ（ケイ酸カルシウム）、ハイドロタ
ルサイト、炭酸ナトリウム、炭酸カリウム、炭酸マグネシウム、炭酸カルシウム、炭酸バ
リウム、炭酸ランタン、炭酸セリウム、塩基性チタン酸塩、塩基性ケイチタン酸塩、塩基
性酢酸銅、塩基性硫酸鉛、層状複水酸化物（Ｍｇ－Ａｌタイプ、Ｍｇ－Ｆｅタイプ、Ｎｉ
－Ｆｅタイプ、Ｌｉ－Ａｌタイプ）、層状複水酸化物－アルミナシリカゲル複合体、ベー
マイト、アルミナ、酸化亜鉛、酸化鉛、酸化鉄、オキシ水酸化鉄、ヘマタイト、酸化ビスマス、酸化スズ、酸化チタン、酸化ジルコニウム等の陰イオン吸着材、リン酸ジルコニウ
ム、リン酸チタニウム、アパタイト、非塩基性チタン酸塩、ニオブ酸塩、ニオブ・チタン
酸塩等の陽イオン吸着材、ゼオライト、硫酸カルシウム、硫酸マグネシウム、硫酸アルミ
ニウム、石膏、硫酸バリウム、アルミナ三水和物（ＡＴＨ）、ヒュームドシリカ、沈殿シ
リカ、ジルコニア、及びイットリア等の酸化物系セラミックス、窒化ケイ素、窒化チタン、及び窒化ホウ素等の窒化物系セラミックス、シリコンカーバイド、カオリナイト、タル
ク、ディカイト、ナクライト、ハロイサイト、パイロ無機粒子イト、モンモリロナイト、セリサイト、アメサイト、ベントナイト等の層状シリケート、アスベスト、ケイ藻土、ガラス繊維、合成層状シリケート、例えば、雲母又はフルオロ雲母、及びホウ酸亜鉛から成る群から選択される。これらは１種単独で用いてもよく、２種以上を併用してもよい。これらのなかでも特に硫酸バリウムが好ましく、より好ましくは、沈降性硫酸バリウムである。具体的には、炭酸バリウム、又は硫化バリウムに硫酸を加えることによって硫酸バリウムを得る方法（硫酸法）、塩化バリウムに硫酸ナトリウムを加えることによって硫酸バリウムを得る方法（芒硝法）で得られる硫酸バリウム粒子である。合成法により作製された硫酸バリウム粒子を用いることにより、無機粒子の体積平均粒子径の制御を精度良く行うことができる。
本発明における無機粒子は、ＢＥＴ比表面積が６．５ｍ２／ｇ以上、３０ｍ２／ｇ以下であり、好ましくは１０ｍ２／ｇ以上、２５ｍ２／ｇ以上であり、より好ましくは１５ｍ２／ｇ以上、２０ｍ２／ｇ以下である。ＢＥＴ比表面積が６．５ｍ２／ｇより小さいと、耐熱性多孔層の無機粒子同士の接点が少なくなることで、耐熱性多孔質層の構造がもろくなり、高温時にポリオレフィン多孔質膜の収縮を抑制することが困難となったり、電池の製造工程で耐熱性多孔層が脱落して電池へ混入することで電池の不良率が高くなる場合がある。ＢＥＴ比表面積が３０ｍ２／ｇより大きいと、無機粒子間の空隙が少なくなり、電池内でのリチウムイオンの移動経路が狭くなったり、長くなることで電気抵抗度が大きくなる場合がある。さらに、ポリオレフィン多孔質膜の細孔に無機粒子が目詰まりすることで、電池の性能を著しく低下させる場合もある。ＢＥＴ比表面積が６．５ｍ２／ｇ以上、３０ｍ２／ｇ以下の無機粒子であると、耐熱性多孔層の耐熱収縮性が損なわれることなく、耐熱性多孔層の脱落を少なくすることができる。
[Inorganic particles]
The inorganic particles of the present invention are not particularly limited in material as long as they are electrochemically stable. Specifically, sodium oxide, potassium oxide, magnesium oxide, calcium oxide, barium oxide, lanthanum oxide, cerium oxide, strontium oxide, vanadium oxide, SiO 2
-MgO (magnesium silicate), SiO 2 -CaO (calcium silicate), hydrotalcite, sodium carbonate, potassium carbonate, magnesium carbonate, calcium carbonate, barium carbonate, lanthanum carbonate, cerium carbonate, basic titanate, base Sex silicate, basic copper acetate, basic lead sulfate, layered compound hydroxide (Mg-Al type, Mg-Fe type, Ni)
-Fe type, Li-Al type), layered compound hydroxide-alumina silica gel composite, boehmite, alumina, zinc oxide, lead oxide, iron oxide, iron oxyhydroxide, hematite, bismuth oxide, tin oxide, titanium oxide, Anion adsorbents such as zirconium oxide, cation adsorbents such as zirconium phosphate, titanium phosphate, apatite, non-basic titanate, niobate, niobite, zeolite, calcium sulfate, magnesium sulfate, Oxide-based ceramics such as aluminum sulfate, gypsum, barium sulfate, alumina trihydrate (ATH), fumed silica, precipitated silica, zirconia, and ittoria, and nitride-based ceramics such as silicon nitride, titanium nitride, and boron nitride. Layered silicates such as silicon carbide, kaolinite, talc, dikite, nacrite, halloysite, pyroinorganic particleite, montmorillonite, cericite, amesite, bentonite, asbestos, coconut soil, glass fiber, synthetic layered silicate, for example, mica. Alternatively, it is selected from the group consisting of fluoromica and zinc borate. These may be used alone or in combination of two or more. Among these, barium sulfate is particularly preferable, and more preferably barium sulfate is precipitating barium sulfate. Specifically, barium sulfate obtained by a method of obtaining barium sulfate by adding sulfuric acid to barium carbonate or barium sulphate (sulfuric acid method) and a method of obtaining barium sulfate by adding sodium sulfate to barium chloride (barium sulfate method). It is a particle. By using the barium sulfate particles produced by the synthetic method, the volume average particle size of the inorganic particles can be controlled with high accuracy.
The inorganic particles in the present invention have a BET specific surface area of 6.5 m 2 / g or more and 30 m 2 / g or less, preferably 10 m 2 / g or more, 25 m 2 / g or more, and more preferably 15 m 2 / g. The above is 20 m 2 / g or less. When the BET specific surface area is smaller than 6.5 m 2 / g, the contact points between the inorganic particles of the heat-resistant porous layer are reduced, so that the structure of the heat-resistant porous layer becomes brittle and the polyolefin porous film shrinks at high temperatures. It may be difficult to suppress the battery, or the heat-resistant porous layer may fall off and be mixed into the battery in the manufacturing process of the battery, so that the defective rate of the battery may increase. When the BET specific surface area is larger than 30 m 2 / g, the voids between the inorganic particles are reduced, and the movement path of lithium ions in the battery is narrowed or lengthened, which may increase the electrical resistance. Further, the pores of the porous polyolefin membrane may be clogged with inorganic particles, which may significantly reduce the performance of the battery. When the BET specific surface area is 6.5 m 2 / g or more and 30 m 2 / g or less, the heat-resistant porous layer can be reduced from falling off without impairing the heat-resistant shrinkage. ..
［水溶性高分子］
本発明で用いる水溶性高分子は、高分子骨格に、アミノ基、アミド基、カルボニル基、カルボキシル基、スルホニル基、リン酸基、水酸基、アルキル基およびハロゲン基からなる群から選ばれる少なくとも１つの官能基を含んでいる。この事により耐熱性多孔層を構成する無機粒子同士を結着させる効果、及び耐熱性多孔層をポリオレフィン多孔質膜と密着させる効果を発現することができる。水溶性高分子として、特に限定されるものではないが、具体的には（メタ）アクリル酸共重合樹脂、ポリアクリルアミド樹脂、ポリビニルアルコール樹脂、ポリアミド樹脂、ポリ（メタ）アラミド樹脂、ポリエチレングリコール樹脂、セルロースエーテル樹脂、の群より選ばれる１つ以上を使用することができ、中でも、セルロースエーテル樹脂、ポリビニルアルコール樹脂、ポリアクリルアミド樹脂が好ましく、セルロースエーテル樹脂、ポリアクリルアミド樹脂がさらに好ましい。これらの水溶性高分子は、単独あるいは二種以上を混合して用いてもよい。ここで言う水溶性高分子とは少なくとも１５０℃以上の耐熱性を持つものである。例えば、市販されている水溶液を使用することができ、アクリル系樹脂として、具体的には、東亜合成株式会社製“ジュリマー”（登録商標）ＡＴ－２１０、ＥＴ－４１０、“アロン”（登録商標）Ａ－１０４、ＡＳ－２０００、ＮＷ－７０６０、荒川化学株式会社製“ポリストロン”（登録商標）１１７、７０５、１２８０、昭和電工株式会社製“コーガム”（登録商標）シリーズ等が挙げられる。ポリビニルアルコールとして、クラレ株式会社製“クラレポバール”（登録商標）３－９８、３－８８、三菱ケミカル株式会社製“ゴーセノール”（登録商標）Ｎ－３００、ＧＨ－２０等が挙げられる。セルロース系樹脂として、日本製紙株式会社製“サンローズ”（登録商標）ＭＡＣシリーズ等が挙げられる。
［その他添加剤］
前記耐熱性多孔層には、無機粒子の分散安定性を向上させる目的の分散剤や、塗工性を
向上させる目的で増粘剤及び濡れ剤等、耐熱性を向上させる目的で熱硬化剤及び架橋剤等
を適宜含んでもよい。市販されている水溶液又は水分散体を使用することができ、アクリ
ル系樹脂として、具体的には、昭和電工株式会社製“ポリゾール”シリーズ、日本ゼオン(
株)製“ＢＭ”シリーズ、東亜合成株式会社製“ジュリマー”（登録商標）ＡＴ－２１０、
ＥＴ－４１０、“アロン”（登録商標）Ａ－１０４、ＡＳ－２０００、ＮＷ－７０６０、
トーヨーケム株式会社製“ＬＩＯＡＭＬＵＭ”（登録商標）シリーズ、ＪＳＲ株式会社製 ＴＲＤ２０２Ａ、ＴＲＤ１０２Ａ、荒川化学株式会社製“ポリストロン”（登録商標）１１７、７０５、１２８０、昭和電工株式会社製“コーガム”（登録商標）シリーズ、大成ファインケミカル株式会社製 ＷＥＭ－２００Ｕ、及びＷＥＭ－３０００等が挙げられる。ポリビニルアルコールとして、クラレ株式会社製“クラレポバール”（登録商標）３－９８、３－８８、三菱ケミカル株式会社製“ゴーセノール”（登録商標）Ｎ－３００、ＧＨ－２０等が
挙げられる。
［耐熱性多孔層の重量組成比］
本発明の実施形態における耐熱性多孔層に含まれる無機粒子の含有量は、耐熱性多孔質層を形成する組成物の合計を１００質量％として９２質量％以上、９９質量％以下である。より好ましくは９３質量％以上、９８質量％以下であり、さらに好ましくは９４質量％以上、９７質量％以下である。無機粒子の含有量が９２質量％より小さいと、高温時にポリオレフィン多孔質膜が収縮するのを抑制することが困難となる場合がある。無機粒子の含有量が９９質量％より大きいと、無機粒子同士を結着している組成物が少ないために、耐熱性多孔層の脱落が多くなる場合がある。
[Water-soluble polymer]
The water-soluble polymer used in the present invention is at least one selected from the group consisting of an amino group, an amide group, a carbonyl group, a carboxyl group, a sulfonyl group, a phosphate group, a hydroxyl group, an alkyl group and a halogen group in the polymer skeleton. Contains functional groups. As a result, the effect of binding the inorganic particles constituting the heat-resistant porous layer and the effect of adhering the heat-resistant porous layer to the polyolefin porous film can be exhibited. The water-soluble polymer is not particularly limited, but specifically, (meth) acrylic acid copolymer resin, polyacrylamide resin, polyvinyl alcohol resin, polyamide resin, poly (meth) aramid resin, polyethylene glycol resin, etc. One or more selected from the group of cellulose ether resins can be used, and among them, cellulose ether resin, polyvinyl alcohol resin and polyacrylamide resin are preferable, and cellulose ether resin and polyacrylamide resin are more preferable. These water-soluble polymers may be used alone or in combination of two or more. The water-soluble polymer referred to here has a heat resistance of at least 150 ° C. or higher. For example, a commercially available aqueous solution can be used, and as the acrylic resin, specifically, "Julimer" (registered trademark) AT-210, ET-410, "Aron" (registered trademark) manufactured by Toa Synthetic Co., Ltd. can be used. ) A-104, AS-2000, NW-7060, "Policetron" (registered trademark) 117, 705, 1280 manufactured by Arakawa Chemical Co., Ltd., "Cogam" (registered trademark) series manufactured by Showa Denko KK, and the like. Examples of polyvinyl alcohol include "Kuraray Poval" (registered trademark) 3-98 and 3-88 manufactured by Kuraray Corporation, and "Gosenol" (registered trademark) N-300 and GH-20 manufactured by Mitsubishi Chemical Corporation. Examples of the cellulosic resin include "Sunrose" (registered trademark) MAC series manufactured by Nippon Paper Industries, Ltd.
[Other additives]
The heat-resistant porous layer includes a dispersant for the purpose of improving the dispersion stability of inorganic particles, a thickener and a wetting agent for the purpose of improving coatability, and a thermosetting agent for the purpose of improving heat resistance. A cross-linking agent or the like may be appropriately contained. Commercially available aqueous solutions or aqueous dispersions can be used, and as acrylic resins, specifically, "Polysol" series manufactured by Showa Denko KK, Nippon Zeon (
"BM" series manufactured by Toa Synthetic Co., Ltd., "Julimer" (registered trademark) AT-210, manufactured by Toagosei Co., Ltd.
ET-410, "Aron" (registered trademark) A-104, AS-2000, NW-7060,
"LIOAMLUM" (registered trademark) series manufactured by Toyochem Co., Ltd., TRD202A, TRD102A manufactured by JSR Corporation, "Polystron" (registered trademark) manufactured by Arakawa Chemical Co., Ltd. 117, 705, 1280, "Cogam" manufactured by Showa Denko Corporation (registered) Trademark) series, WEM-200U manufactured by Taisei Fine Chemicals Co., Ltd., WEM-3000 and the like. Examples of polyvinyl alcohol include "Kuraray Poval" (registered trademark) 3-98 and 3-88 manufactured by Kuraray Corporation, and "Gosenol" (registered trademark) N-300 and GH-20 manufactured by Mitsubishi Chemical Corporation.
[Weight composition ratio of heat-resistant porous layer]
The content of the inorganic particles contained in the heat-resistant porous layer in the embodiment of the present invention is 92% by mass or more and 99% by mass or less, assuming that the total composition forming the heat-resistant porous layer is 100% by mass. It is more preferably 93% by mass or more and 98% by mass or less, and further preferably 94% by mass or more and 97% by mass or less. If the content of the inorganic particles is less than 92% by mass, it may be difficult to suppress the shrinkage of the polyolefin porous membrane at high temperatures. When the content of the inorganic particles is larger than 99% by mass, the heat-resistant porous layer may come off more often because the composition that binds the inorganic particles to each other is small.
［耐熱性多孔層の平均厚さ］
本発明の実施形態における耐熱性多孔層の平均厚さは、０．５μｍ以上、４．０μｍ以下であることが好ましい。より好ましくは１．０μｍ以上、３．０μｍ以下であり、さらに好ましくは１．５μｍ以上、２．５μｍ以下である。耐熱性多孔層の厚さが０．５μｍより小さいと、熱によるポリオレフィン多孔質膜の収縮を抑制することができなくなる場合がある。耐熱性多孔層の平均厚さが４．０μｍより大きいと、電池セルの正極と負極の極間距離が大きくなるために、電気抵抗度が大きくなったり、電池の体積に占める電池用セパレータの割合が多くなり、電池の体積エネルギー密度が低くなる場合がある。耐熱性多孔質層の平均厚さが０．５μｍ以上、４．０μｍ以下であると、耐熱性多孔層によるポリオレフィン多孔質膜の熱収縮抑制効果が得られ、電気抵抗度が大きくなることがない。また、電池用セパレータの厚さに占める耐熱性多孔質の厚さの割合が多いほど、耐熱性多孔層によるポリオレフィン多孔質膜の熱収縮抑制効果は大きくなる。
[Average thickness of heat-resistant porous layer]
The average thickness of the heat-resistant porous layer in the embodiment of the present invention is preferably 0.5 μm or more and 4.0 μm or less. It is more preferably 1.0 μm or more and 3.0 μm or less, and further preferably 1.5 μm or more and 2.5 μm or less. If the thickness of the heat-resistant porous layer is less than 0.5 μm, it may not be possible to suppress the shrinkage of the polyolefin porous membrane due to heat. If the average thickness of the heat-resistant porous layer is larger than 4.0 μm, the distance between the positive and negative poles of the battery cell becomes large, so that the electrical resistance increases or the ratio of the battery separator to the volume of the battery. May increase and the volume energy density of the battery may decrease. When the average thickness of the heat-resistant porous layer is 0.5 μm or more and 4.0 μm or less, the heat-resistant porous layer has an effect of suppressing heat shrinkage of the polyolefin porous film, and the electrical resistance does not increase. .. Further, the larger the ratio of the thickness of the heat-resistant porous material to the thickness of the battery separator, the greater the effect of the heat-resistant porous layer on suppressing the heat shrinkage of the polyolefin porous membrane.
［耐熱性多孔層の形成方法］
本発明における耐熱性多孔層は以下の工程で得ることができる。
（ａ）無機粒子と水溶性高分子と添加剤と分散媒を用いた耐熱性多孔層用塗工液の作製。
（ｂ）ポリオレフィン多孔質膜の少なくとも片面、又は両面に前記塗工液を塗工する工程。
（ｃ）前記塗工後、分散媒をドライヤーで乾燥させ、耐熱性多孔層を形成する工程。
[Method for forming a heat-resistant porous layer]
The heat-resistant porous layer in the present invention can be obtained by the following steps.
(A) Preparation of a coating liquid for a heat-resistant porous layer using inorganic particles, a water-soluble polymer, an additive, and a dispersion medium.
(B) A step of applying the coating liquid to at least one side or both sides of the porous polyolefin membrane.
(C) A step of drying the dispersion medium with a dryer after the coating to form a heat-resistant porous layer.
前記工程（ａ）において、分散媒として水を用いることが好ましい。耐熱性多孔層用塗工液の分散安定性を損なわない範囲であれば、分散媒として水にエタノール、イソプロパノール、Ｎ－メチルピロリドンなどの親水性の溶媒を混ぜたものを使用してもよい。耐熱性多孔層用塗工液を分散処理する方法は、公知の方法を用いることができる。例えば、ボールミル、ビーズミル、遊星ボールミル、振動ボールミル、サンドミル、コロイドミル、ロールミル、高速インペラー分散、ディスパーザー、ホモジナイザー、プラネタリーミキサーおよび遊星式混練機、超音波分散、撹拌羽根等による機械撹拌等が挙げられる。分散が不十分であると、耐熱性多孔層によるポリオレフィン多孔質膜の熱収縮抑制効果が低下する場合がある。 In the step (a), it is preferable to use water as the dispersion medium. As long as the dispersion stability of the heat-resistant porous layer coating liquid is not impaired, water may be mixed with a hydrophilic solvent such as ethanol, isopropanol, or N-methylpyrrolidone. As a method for dispersing the heat-resistant porous layer coating liquid, a known method can be used. For example, ball mills, bead mills, planetary ball mills, vibration ball mills, sand mills, colloidal mills, roll mills, high-speed impeller dispersions, dispersers, homogenizers, planetary mixers and planetary kneaders, ultrasonic dispersions, mechanical stirring with stirring blades, etc. Be done. Insufficient dispersion may reduce the effect of the heat-resistant porous layer on suppressing heat shrinkage of the porous polyolefin membrane.
前記工程（ｂ）において、ポリオレフィン多孔質膜の少なくとも片面又は両面に耐熱性
多孔層用塗工液を塗工する方法は公知の方法を用いることができる。例えば、ダイレクトグラビアコート法、リバースグラビアコート法、キスリバースグラビアコート法、ダイレクトバーコート法、ロールブラッシュ法、エアナイフコート法、マイヤーバーコート法、パイプドクター法、ブレードコート法及びダイコート法等が挙げられ、これらの方法は単独又は組み合わせて行うことができる。
In the step (b), a known method can be used as a method for applying the heat-resistant porous layer coating liquid to at least one side or both sides of the polyolefin porous film. Examples thereof include a direct gravure coat method, a reverse gravure coat method, a kiss reverse gravure coat method, a direct bar coat method, a roll brush method, an air knife coat method, a Meyer bar coat method, a pipe doctor method, a blade coat method and a die coat method. , These methods can be performed alone or in combination.
本発明の実施形態に係る電池用セパレータは、ニッケル－水素電池、ニッケル－カドミ
ウム電池、ニッケル－亜鉛電池、銀－亜鉛電池、リチウムイオン二次電池、リチウムポリ
マー二次電池、及びリチウム－硫黄電池等の二次電池等の電池用セパレータとして用いる
ことができる。特に、リチウムイオン二次電池のセパレータとして用いるのが好ましい。
The battery separator according to the embodiment of the present invention includes a nickel-hydrogen battery, a nickel-cadmium battery, a nickel-zinc battery, a silver-zinc battery, a lithium ion secondary battery, a lithium polymer secondary battery, a lithium-sulfur battery, and the like. It can be used as a battery separator for a secondary battery or the like. In particular, it is preferable to use it as a separator for a lithium ion secondary battery.
以下、実施例を示して具体的に説明するが、本発明はこれらの実施例よって何ら制限されるものではない。なお、実施例中の測定値は以下の方法で得た値である。 Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The measured values in the examples are the values obtained by the following methods.
１．ＢＥＴ比表面積（ｍ２／ｇ）
ＪＩＳ Ｚ ８８３０（２０１３）に準じ、比表面積測定装置（株式会社マウンテック製、全自動比表面積測定装置“Ｍａｃｓｏｒｂ”（登録商標）ＨＭ Ｍｏｄｅｌ－１２２０）を用いて測定した。
1. 1. BET specific surface area (m 2 / g)
Measurement was performed using a specific surface area measuring device (manufactured by Mountech Co., Ltd., fully automated specific surface area measuring device "Macsorb" (registered trademark) HM Model-1220) according to JIS Z 8830 (2013).
２．無機粒子の粒子径（μｍ）
無機粒子の粒子径は、ＪＩＳ Ｚ ８８２５（２０１３）に従いレーザー回折式粒度分布測定装置（株式会社堀場製作所製、ＬＡ－９６０Ｖ２）を用いて、体積基準積算率が５０％のときの粒子径Ｄ５０（μｍ）を測定した。
３．厚さ（μｍ）
ポリオレフィン多孔質膜及び電池用セパレータを接触式膜厚計（株式会社ミツトヨ製、“ライトマチック”（登録商標））を使用して、超硬球面測定子φ１０．５ｍｍ、加重０．１５Ｎの条件で測定し、５点の測定値を平均することによって厚さを求めた。さらに、耐熱性多孔層の厚さは、電池用セパレータを前記耐熱性多孔層用塗工液に含まれる分散媒と同じ分散媒で洗浄し、耐熱性多孔層を除去したポリオレフィン多孔質膜を前記接触式膜厚計にて測定し、下記の計算式にて得た。
2. 2. Particle size of inorganic particles (μm)
The particle size of the inorganic particles is determined by using a laser diffraction type particle size distribution measuring device (LA-960V2, manufactured by HORIBA, Ltd.) according to JIS Z 8825 (2013), and the particle size is D50 (when the volume-based integration rate is 50%). μm) was measured.
3. 3. Thickness (μm)
Using a contact-type film thickness meter (Mitutoyo Co., Ltd., "Lightmatic" (registered trademark)), a porous polyolefin film and a separator for batteries are used under the conditions of a super hard spherical meter φ10.5 mm and a weight of 0.15 N. The thickness was obtained by measuring and averaging the measured values at 5 points. Further, the thickness of the heat-resistant porous layer is determined by washing the battery separator with the same dispersion medium as the dispersion medium contained in the heat-resistant porous layer coating liquid, and removing the heat-resistant porous layer from the polyolefin porous film. It was measured with a contact film thickness meter and obtained by the following formula.
耐熱性多孔層の厚さ＝電池用セパレータの厚さ－ポリオレフィン多孔質膜の厚さ
４．透気抵抗度（ｓｅｃ/１００ｍｌＡｉｒ）
ＪＩＳ Ｐ ８１１７に準じ、王研式透気抵抗度計（旭精工株式会社製、ＥＧＯ-１Ｔ）を使用して、５点の測定値を平均することによって透気抵抗度を求めた。耐熱性多孔層による透気抵抗度上昇量は、電池用セパレータを前記耐熱性多孔層用塗工液に含まれる分散媒と同じ分散媒で洗浄し、耐熱性多孔層を除去したポリオレフィン多孔質膜を前記王研式透気抵抗度計にて測定し、下記の計算式にて得た。
Thickness of heat-resistant porous layer = Thickness of battery separator-Thickness of polyolefin porous membrane 4. Air permeability resistance (sec / 100mlAir)
According to JIS P 8117, the air permeability resistance was determined by averaging the measured values at 5 points using a Wangken type air permeability resistance meter (EGO-1T manufactured by Asahi Seiko Co., Ltd.). The amount of increase in air permeability resistance due to the heat-resistant porous layer is determined by washing the battery separator with the same dispersion medium as the dispersion medium contained in the heat-resistant porous layer coating liquid to remove the heat-resistant porous layer. Was measured with the Oken type air permeability resistance meter and obtained by the following formula.
透気抵抗度上昇量＝電池用セパレータの透気抵抗度－ポリオレフィン多孔質膜の透気抵抗度
５．熱収縮率（％）
電池用セパレータのＭＤ方向（長さ方向）とＴＤ方向（幅方向）の熱収縮率は下記の方法にて測定した。
（１）電池用セパレータをＭＤ方向１００ｍｍ×ＴＤ方向１００ｍｍの大きさに３枚切り出し、透明なガラススケール（測定精度０．１ｍｍ）を用いて、電池用セパレータの対辺の中点同士の距離をＭＤ方向の長さ、ＴＤ方向の長さとして測定し、初期寸法（ｍｍ）と
する。
（２）前記電池用セパレータをＡ３サイズの紙２枚で挟み、温度１５０℃のオーブンに入れ、１時間放置した後、オーブンから電池用セパレータを取り出して３０分間室温で放置した。
（３）前記ガラススケールを用いて、電池用セパレータの対辺の中点同士の距離を再度測定し、収縮後の寸法（ｍｍ）とした。この時の測定位置は初期寸法を測定した位置と
同じ位置であり、電池用セパレータの端部がカールしていた場合は、広げて測定を実施し
た。得られた初期寸法と、収縮後の寸法より、下記計算式にてＭＤ方向、及びＴＤ方向の熱収縮率（％）を得た。
Amount of increase in air permeability resistance = Air permeability resistance of battery separator-Air permeability resistance of polyolefin porous membrane 5. Heat shrinkage rate (%)
The heat shrinkage in the MD direction (length direction) and the TD direction (width direction) of the battery separator was measured by the following method.
(1) Cut out three battery separators into a size of 100 mm in the MD direction x 100 mm in the TD direction, and use a transparent glass scale (measurement accuracy 0.1 mm) to determine the distance between the midpoints on the opposite sides of the battery separator. Measured as the length in the direction and the length in the TD direction, and set to the initial dimension (mm).
(2) The battery separator was sandwiched between two sheets of A3 size paper, placed in an oven at a temperature of 150 ° C. and left for 1 hour, and then the battery separator was taken out from the oven and left at room temperature for 30 minutes.
(3) Using the glass scale, the distance between the midpoints on the opposite sides of the battery separator was measured again and used as the dimension (mm) after shrinkage. The measurement position at this time was the same as the position where the initial dimensions were measured, and if the end of the battery separator was curled, the measurement was performed by expanding it. From the obtained initial dimensions and the dimensions after shrinkage, the heat shrinkage rate (%) in the MD direction and the TD direction was obtained by the following formula.
熱収縮率（％）＝｛初期寸法（ｍｍ）－収縮後の寸法（ｍｍ）｝／初期寸法（ｍｍ）×１００
６．耐熱性多孔層の脱落量（ｍｇ）
電池用セパレータからの耐熱性多孔層の脱落量は摩擦測定機（株式会社トリニティーラボ製、静・動摩擦測定機ＴＬ２０１Ｔｔを用いて、下記の方法にて測定した。
（１）電池用セパレータをＴＤ方向４９ｍｍ×ＭＤ方向１１０ｍｍの大きさに切り出し、電子天秤（測定精度０．０１ｍｇ）を用いて、重量（ｍｇ）を測定した。
（２）５０ｍｍ×５０ｍｍに切り出した片面粘着クッションテープ（トラスコ中山株式会社製、エッジクッションテープＴＥＣ－５０ＢＫ）を接触面に貼った５０ｍｍ×５０ｍｍの平面接触子に、前記クッションテープとポリオレフィン多孔質膜面（片面に耐熱性多孔層を有する電池用セパレータの場合）もしくは測定しない耐熱性多孔層面（両面に耐熱性多孔層を有する電池用セパレータの場合）が接するように前記電池用セパレータを固定する。
（３）９０ｍｍ×２２０ｍｍに切り出した研磨フィルム＃６０００（３ＭＴＭ製、フィルム研磨材Ａ３－２ＳＨＴ）を前記静・動摩擦測定機の摺動部に水平に固定する。
（４）前記研磨フィルムと前記接触子に固定した電池用セパレータの耐熱性多孔層を接触させ、前記接触子に１ｋｇの重りを載せる。この際の研磨フィルムと耐熱性多孔層の接触面積は４９ｍｍ×５０ｍｍとなる。
（５）前記静・動摩擦測定機の摺動部を水平方向に速度１０ｍｍ／ｓｅｃ、距離２５ｍｍ、往復５回摺動させた後、前記接触子から電池用セパレータを取り外し、電子天秤（測定精度０．０１ｍｇ）を用いて、重量（ｍｇ）を測定した。
（６）得られた試験前後の電池用セパレータの重量（ｍｇ）より、下記計算式にて耐熱性多孔層の脱落量（ｍｇ）を得た。
Heat shrinkage rate (%) = {initial dimension (mm) -dimension after shrinkage (mm)} / initial dimension (mm) x 100
6. Amount of heat-resistant porous layer dropped off (mg)
The amount of the heat-resistant porous layer dropped from the battery separator was measured by the following method using a friction measuring machine (manufactured by Trinity Lab Co., Ltd., static / dynamic friction measuring machine TL201Tt).
(1) A battery separator was cut into a size of 49 mm in the TD direction × 110 mm in the MD direction, and the weight (mg) was measured using an electronic balance (measurement accuracy 0.01 mg).
(2) The cushion tape and the polyolefin porous film are attached to a 50 mm × 50 mm flat contactor to which a single-sided adhesive cushion tape (manufactured by TRUSCO NAKAYAMA Co., Ltd., edge cushion tape TEC-50BK) cut out to 50 mm × 50 mm is attached to the contact surface. The battery separator is fixed so that a surface (in the case of a battery separator having a heat-resistant porous layer on one side) or a non-measured heat-resistant porous layer surface (in the case of a battery separator having a heat-resistant porous layer on both sides) is in contact.
(3) The polishing film # 6000 (manufactured by 3M TM , film polishing material A3-2SHT) cut out to 90 mm × 220 mm is horizontally fixed to the sliding portion of the static / dynamic friction measuring machine.
(4) The polishing film is brought into contact with the heat-resistant porous layer of the battery separator fixed to the contactor, and a weight of 1 kg is placed on the contactor. At this time, the contact area between the polishing film and the heat-resistant porous layer is 49 mm × 50 mm.
(5) After sliding the sliding portion of the static / dynamic friction measuring machine in the horizontal direction at a speed of 10 mm / sec, a distance of 25 mm, and reciprocating 5 times, the battery separator is removed from the contactor, and an electronic balance (measurement accuracy 0). The weight (mg) was measured using 0.01 mg).
(6) From the weight (mg) of the battery separator obtained before and after the test, the amount of the heat-resistant porous layer dropped (mg) was obtained by the following formula.
耐熱性多孔層の脱落量（ｍｇ）＝試験前の電池用セパレータの重量（ｍｇ）－試験後の電池用セパレータの重量（ｍｇ）
７．耐熱性多孔層の１８０°剥離強度（Ｎ／ｍ）
耐熱性多孔層の１８０°剥離強度は卓上形精密万能試験機（株式会社島津製作所製、オートグラフＡＧＳ－Ｘ）を用いて、下記の方法にて測定した。
（１）電池用セパレータをＴＤ方向２５ｍｍ×ＭＤ方向１００ｍｍの大きさに切り出す。
（２）前記電池用セパレータのポリオレフィン多孔質膜面（片面に耐熱性多孔層を有する電池用セパレータの場合）もしくは測定しない耐熱性多孔層面（両面に耐熱性多孔層を有する電池用セパレータの場合）に、２０ｍｍ×９０ｍｍの大きさに切り出したフィルム両面テープを貼り、ゴムローラー（テスター産業株式会社製、ＳＡ－１００３－Ｂテープ圧着ロール手動型、ロール重量２ｋｇ、ゴム硬度８０±５Ｈｓ）を用いて１往復圧着する。（３）前記フィルム両面テープの剥離ライナーを剥がした後、５０ｍｍ×１５０ｍｍの金属板に前記電池用セパレータを固定する。
（４）前記金属板に固定した電池用セパレータの耐熱性多孔層面に片面粘着テープ（ニチバン株式会社製、“セロテープ”（登録商標）Ｎｏ．４０５）１５ｍｍ幅を貼り、前記ゴムローラーを用いて５往復圧着した。
（５）前記電池用セパレータが固定された金属板を前記卓上形精密万能試験機に垂直に固定し、前記片面粘着テープを圧着してから５分以内に、前記片面粘着テープを１８０°方向、１００ｍｍ／ｓｅｃの速度で剥離し、剥離距離４０ｍｍから１００ｍｍまでの強度の平均値を求めた。
（６）得られた剥離強度と前記片面粘着テープの幅より、下記計算式にて耐熱性多孔層の１８０°剥離強度（Ｎ／ｍ）を得た。
Amount of heat-resistant porous layer dropped off (mg) = Weight of battery separator before test (mg) -Weight of battery separator after test (mg)
7. 180 ° peel strength (N / m) of heat-resistant porous layer
The 180 ° peel strength of the heat-resistant porous layer was measured by the following method using a desktop precision universal testing machine (manufactured by Shimadzu Corporation, Autograph AGS-X).
(1) Cut out a battery separator into a size of 25 mm in the TD direction x 100 mm in the MD direction.
(2) Polyolefin porous film surface of the battery separator (in the case of a battery separator having a heat-resistant porous layer on one side) or a heat-resistant porous layer surface not measured (in the case of a battery separator having a heat-resistant porous layer on both sides) A film double-sided tape cut out to a size of 20 mm × 90 mm is attached to the tape, and a rubber roller (manufactured by Tester Sangyo Co., Ltd., SA-1003-B tape crimping roll manual type, roll weight 2 kg, rubber hardness 80 ± 5 Hs) is used. Press back and forth once. (3) After peeling off the release liner of the film double-sided tape, the battery separator is fixed to a metal plate of 50 mm × 150 mm.
(4) A single-sided adhesive tape (“Cellotape” (registered trademark) No. 405 manufactured by Nichiban Co., Ltd.) with a width of 15 mm is attached to the heat-resistant porous layer surface of the battery separator fixed to the metal plate, and 5 using the rubber roller. Reciprocating crimping.
(5) Within 5 minutes after the metal plate to which the battery separator is fixed is vertically fixed to the desktop precision universal testing machine and the single-sided adhesive tape is crimped, the single-sided adhesive tape is placed in the 180 ° direction. The peeling was performed at a speed of 100 mm / sec, and the average value of the strengths from the peeling distance of 40 mm to 100 mm was obtained.
(6) From the obtained peel strength and the width of the single-sided adhesive tape, 180 ° peel strength (N / m) of the heat-resistant porous layer was obtained by the following formula.
耐熱性多孔層の１８０°剥離強度（Ｎ／ｍ）＝得られた剥離強度（Ｎ）／片面粘着テープの幅（ｍｍ）
８．電池の不良率
［正極の作製］
バインダーとしてＰＶＤＦを１．２質量部含むＮＭＰ溶液を、活物質としてのコバルト
酸リチウム９７質量部、カーボンブラック１．８質量部に加えて混合し、正極合剤含有ス
ラリーとした。この正極合剤含有スラリーを、厚みが２０μｍのアルミ箔からなる正極集
電体の両面に均一に塗布して乾燥して正極層を形成し、その後、ロールプレス機により圧
縮成型して集電体を除いた正極層の密度を３．６ｇ／ｃｍ３にして正極を作製した。
180 ° peel strength (N / m) of heat-resistant porous layer = obtained peel strength (N) / width of single-sided adhesive tape (mm)
8. Battery defect rate [Preparation of positive electrode]
An NMP solution containing 1.2 parts by mass of PVDF as a binder was added to 97 parts by mass of lithium cobalt oxide and 1.8 parts by mass of carbon black as active materials and mixed to obtain a positive electrode mixture-containing slurry. This positive electrode mixture-containing slurry is uniformly applied to both sides of a positive electrode current collector made of aluminum foil having a thickness of 20 μm and dried to form a positive electrode layer, and then compression-molded by a roll press machine to form a current collector. A positive electrode was prepared by setting the density of the positive electrode layer excluding the above to 3.6 g / cm 3 .
［負極の作製］
カルボキシメチルセルロースナトリウムを１．０質量部含む水溶液を、活物質としての
人造黒鉛９８質量部に加えて混合し、さらにバインダーとして固形分として１．０質量部
含むスチレンブタジエンラテックスを加えて混合して負極合剤含有スラリーとした。この
負極合剤含有スラリーを、厚みが１０μｍの銅箔からなる負極集電体の両面に均一に塗付
して乾燥して負極層を形成し、その後、ロールプレス機により圧縮成形して集電体を除いた負極層の密度を１．４５ｇ／ｃｍ３にして、負極を作製した。
［試験用電池の作製］
上記正極、負極にタブ付けされたものと各微多孔膜を使用して巻回体を作製した。次に、アルミラミネート袋内に巻回体を入れ、電解液（１．１ｍｏｌ／Ｌ，ＬｉＰＦ６，エチレンカーボネート／エチルメチルカーボネート／ジエチレンカーボネート＝３／５／２（体積比）に０．５重量％ビニレンカーボネート、２重量％フルオロエチレンカーボネートを添加したもの）を注液し、真空シーラーにて封止した。次に温度３５℃、０．２Ｃ（Ｃは電池が１時間で満充電できる電流値をあらわし、本電池の場合３００ｍＡとしている）にて全容量の１０％を充電し、１２時間保管後、ガス抜きのためにラミネートの１辺を開け、すぐに真空シーラーで封止した。次に、温度３５℃で、０．１Ｃ、４．３５Ｖ、カットオフ電流０．０５Ｃの定電流定電圧充電した後、０．１Ｃで３．０Ｖまで定電流放電した。これら一連の充放電が初回充放電となる。これを３００ｍＡｈ級の試験用電池とした。
[Manufacturing of negative electrode]
An aqueous solution containing 1.0 part by mass of sodium carboxymethyl cellulose is added to 98 parts by mass of artificial graphite as an active material and mixed, and then styrene-butadiene latex containing 1.0 part by mass as a solid content is added as a binder and mixed to form a negative electrode. A mixture-containing slurry was used. This negative electrode mixture-containing slurry is uniformly applied to both sides of a negative electrode current collector made of a copper foil having a thickness of 10 μm and dried to form a negative electrode layer, and then compression-molded by a roll press to collect electricity. A negative electrode was prepared by setting the density of the negative electrode layer excluding the body to 1.45 g / cm 3 .
[Making test batteries]
A wound body was prepared by using the ones tabbed on the positive electrode and the negative electrode and the microporous membranes. Next, put the winding body in an aluminum laminate bag, and add 0.5 weight to the electrolytic solution (1.1 mol / L, LiPF 6 , ethylene carbonate / ethylmethyl carbonate / diethylene carbonate = 3/5/2 (volume ratio)). % Vinylene carbonate (added with 2% by weight fluoroethylene carbonate) was injected and sealed with a vacuum sealer. Next, charge 10% of the total capacity at a temperature of 35 ° C. and 0.2 C (C represents the current value that the battery can fully charge in 1 hour, and 300 mA in the case of this battery), store it for 12 hours, and then gas. One side of the laminate was opened for punching and immediately sealed with a vacuum sealer. Next, after charging at a constant current constant voltage of 0.1 C, 4.35 V and a cutoff current of 0.05 C at a temperature of 35 ° C., a constant current discharge was performed at 0.1 C to 3.0 V. These series of charges and discharges are the first charge and discharge. This was used as a 300 mAh class test battery.
［電池の不良率（％）]
前記試験用電池を１００個作製し、下記計算式にて求められる初回充放電効率が９５％未満の電池の個数を不良率とした。
[Battery defect rate (%)]
100 test batteries were produced, and the number of batteries having an initial charge / discharge efficiency of less than 95% calculated by the following formula was defined as the defect rate.
初回充放電効率（％）＝初回放電容量／初回充電容量×１００
９．電池の釘刺し試験
前記試験用電池５個を用いてＳＡＥ Ｊ２４６４に準じ、釘刺し試験を実施し、下記の基準により評価した。
発火なし：５個全てで発火なし
発火あり：５個全てで発火あり
（実施例１）
沈降性硫酸バリウム（ＢＥＴ比表面積６．５ｍ２／ｇ、粒子径Ｄ５０＝０．４０μｍ）１００重量部に対し、１．０重量部（有効成分）のポリアクリル酸系分散剤（東亜合成株式会社製、アロン（登録商標）Ａ－６１１４）を用意し、水に加える。次に、ディスパー型の羽根を取り付けた撹拌機（東機産業株式会社製、スリーワンモーター）にて７００ｒｐｍで撹拌しながら、前記沈降性硫酸バリウムを全量加え、１０００ｒｐｍで６０分攪拌して、固形分が６０重量％の混合液を得た。
Initial charge / discharge efficiency (%) = initial discharge capacity / initial charge capacity x 100
9. Battery nailing test A nailing test was conducted using the five test batteries according to SAE J2464 and evaluated according to the following criteria.
No ignition: No ignition in all 5 pieces Ignition: All 5 pieces have ignition (Example 1)
Precipitated barium sulfate (BET specific surface area 6.5 m 2 / g, particle size D50 = 0.40 μm) 1.0 part by weight (active ingredient) of polyacrylic acid dispersant (Toagosei Co., Ltd.) Aaron (registered trademark) A-6114) is prepared and added to water. Next, while stirring at 700 rpm with a stirrer equipped with a disper-type blade (manufactured by Toki Sangyo Co., Ltd., Three-One Motor), add the entire amount of the precipitating barium sulfate and stir at 1000 rpm for 60 minutes to obtain a solid content. Obtained a mixed solution of 60% by weight.
得られた混合液を、ビーズミル分散機（淺田鉄工株式会社製、ピコミルＰＣＭ－ＬＲ）、及びビーズ粒径が０．５ｍｍのジルコニアビーズ（東レ株式会社製、トレセラムφ０．５ｍｍ）を用い、ビーズ充填率６５体積％、周速１０ｍ／ｓｅｃ、流速１６ｋｇ／ｈの条件で３回行い、マスターバッチ液を得た。 The obtained mixed solution is filled with beads using a bead mill disperser (Picomill PCM-LR manufactured by Asada Iron Works Co., Ltd.) and zirconia beads having a bead particle size of 0.5 mm (Treceram φ0.5 mm manufactured by Toray Co., Ltd.). The master batch liquid was obtained three times under the conditions of a rate of 65% by volume, a peripheral speed of 10 m / sec, and a flow rate of 16 kg / h.
得られたマスターバッチ液を前記撹拌機にて７００ｒｐｍで撹拌しながら、水溶性高分子として、ポリアクリルアミド（荒川化学工業株式会社製、ポリストロン）、添加剤として、アクリル樹脂（昭和電工株式会社製、ポリゾールＡＰ－４７３５）２．０重量部（有効成分）、濡れ剤（サンノプコ株式会社製、ＳＮウェット３６６）０．２重量部、及び水を加えた。その後、７００ｒｐｍで１０分撹拌し、固形分５５重量％の塗工液を得た。
得られたスラリーを、厚さ１２μｍのポリオレフィン多孔質膜の片面に、キスリバースグラビア法にて塗工し、温度６０℃で乾燥して、耐熱性多孔層の厚さが３μｍの電池用セパレータを得た。
While stirring the obtained master batch liquid at 700 rpm with the stirrer, polyacrylamide (manufactured by Arakawa Chemical Industry Co., Ltd., Polystron) as a water-soluble polymer and acrylic resin (manufactured by Showa Denko Ltd.) as an additive. , Polysol AP-4735) 2.0 parts by weight (active ingredient), 0.2 parts by weight of a wetting agent (SN Wet 366, manufactured by San Nopco Ltd.), and water were added. Then, the mixture was stirred at 700 rpm for 10 minutes to obtain a coating liquid having a solid content of 55% by weight.
The obtained slurry was applied to one side of a porous polyolefin membrane having a thickness of 12 μm by the kiss reverse gravure method and dried at a temperature of 60 ° C. to obtain a battery separator having a heat-resistant porous layer having a thickness of 3 μm. Obtained.
得られた電池用セパレータについて、透気抵抗度上昇量、１５０℃／１ｈ熱収縮率、耐熱性多孔層の脱落量、耐熱性多孔層の１８０°剥離強度、電池の不良率、及び電池の釘刺し試験を評価した結果を表１に示す。 Regarding the obtained battery separator, the amount of increase in air permeation resistance, 150 ° C / 1h heat shrinkage rate, the amount of heat-resistant porous layer dropped off, 180 ° peel strength of heat-resistant porous layer, battery defect rate, and battery nails. The results of evaluating the stab test are shown in Table 1.
（実施例２）
実施例１の沈降性硫酸バリウムを沈降性硫酸バリウム（ＢＥＴ比表面積１１．１ｍ２／ｇ、粒子径Ｄ５０＝０．２４μｍ）、ビーズミル分散機での分散を７回、ポリアクリルアミドの配合量を３．０重量部に変えた以外は、実施例１と同様に電池用セパレータを得た。
(Example 2)
Disperse barium sulfate of Example 1 with barium sulfate (BET specific surface area 11.1 m 2 / g, particle size D50 = 0.24 μm) 7 times with a bead mill disperser, and add 3 polyacrylamides. A battery separator was obtained in the same manner as in Example 1 except that the weight was changed to 0 parts by weight.
（実施例３）
実施例２のポリオレフィン多孔質膜の厚さを２０μmに変えた以外は、実施例２と同様に電池用セパレータを得た。
(Example 3)
A battery separator was obtained in the same manner as in Example 2 except that the thickness of the polyolefin porous membrane of Example 2 was changed to 20 μm.
（実施例４）
実施例２のポリアクリルアミドの配合量を１．５重量部、アクリル樹脂の配合量を５．０重量部に変えた以外は、実施例２と同様に電池用セパレータを得た。
（実施例５）
実施例１の沈降性硫酸バリウムを沈降性硫酸バリウム（ＢＥＴ比表面積１７．９ｍ２／ｇ、粒子径Ｄ５０＝０．１５μｍ）、ビーズミル分散機での分散を１０回、耐熱性多孔層の厚さを２．５μｍに変えた以外は、実施例１と同様に電池用セパレータを得た。
（実施例６）
実施例２のポリアクリルアミドをカルボキシメチルセルロース（ＧＬ ＣＨＥＭ製、ＳＧ－Ｌ０２）、塗工液の固形分を４０重量％に変えた以外は、実施例２と同様に電池用セパレータを得た。
(Example 4)
A battery separator was obtained in the same manner as in Example 2 except that the blending amount of polyacrylamide of Example 2 was changed to 1.5 parts by weight and the blending amount of acrylic resin was changed to 5.0 parts by weight.
(Example 5)
The sedimentation barium sulfate of Example 1 was dispersed with a sedimentation barium sulfate (BET specific surface area 17.9 m 2 / g, particle size D50 = 0.15 μm) 10 times with a bead mill disperser, and the thickness of the heat-resistant porous layer. A battery separator was obtained in the same manner as in Example 1 except that the value was changed to 2.5 μm.
(Example 6)
A battery separator was obtained in the same manner as in Example 2 except that the polyacrylamide of Example 2 was changed to carboxymethyl cellulose (manufactured by GL CHEM, SG-L02) and the solid content of the coating liquid was changed to 40% by weight.
（比較例１）
実施例１の沈降性硫酸バリウムを沈降性硫酸バリウム（ＢＥＴ比表面積５．５ｍ２／ｇ、粒子径Ｄ５０＝０．５０μｍ）に変えた以外は、実施例１と同様に電池用セパレータを得た。
(Comparative Example 1)
A battery separator was obtained in the same manner as in Example 1 except that the precipitated barium sulfate of Example 1 was changed to a precipitated barium sulfate (BET specific surface area 5.5 m 2 / g, particle size D50 = 0.50 μm). ..
（比較例２）
実施例２の沈降性硫酸バリウムを沈降性硫酸バリウム（ＢＥＴ比表面積３１．０ｍ２／ｇ、粒子径Ｄ５０＝０．０９μｍ）、ビーズミル分散機での分散を１０回、アクリル樹脂の配合量を４．０重量部に変えた以外は、実施例２と同様に電池用セパレータを得た。
(Comparative Example 2)
Disperse barium sulfate of Example 2 with barium sulfate (BET specific surface area 31.0 m 2 / g, particle size D50 = 0.09 μm) 10 times with a bead mill disperser, and add 4 acrylic resins. A battery separator was obtained in the same manner as in Example 2 except that the weight was changed to 0 parts by weight.
（比較例３）
実施例４のアクリル樹脂の配合量を８．０重量部に変えた以外は、実施例４と同様に電池用セパレータを得た。
(Comparative Example 3)
A battery separator was obtained in the same manner as in Example 4 except that the blending amount of the acrylic resin in Example 4 was changed to 8.0 parts by weight.
（比較例４）
実施例１の沈降性硫酸バリウムを簸性硫酸バリウム（ＢＥＴ比表面積９．１ｍ２／ｇ、粒子径Ｄ５０＝０．４０μｍ）に変えた以外は、実施例１と同様に電池用セパレータを得た。
(Comparative Example 4)
A battery separator was obtained in the same manner as in Example 1 except that the precipitated barium sulfate of Example 1 was changed to barium sulfate (BET specific surface area 9.1 m 2 / g, particle size D50 = 0.40 μm). ..
（比較例５）
実施例１の沈降性硫酸バリウムをアルミナ（ＢＥＴ比表面積６．５ｍ２／ｇ、粒子径Ｄ５０＝０．５０μｍ）、ビーズミル分散機での分散を１２回に変えた以外は、実施例１と同様に電池用セパレータを得た。
(Comparative Example 5)
Same as Example 1 except that the sedimentation barium sulfate of Example 1 was changed to alumina (BET specific surface area 6.5 m 2 / g, particle size D50 = 0.50 μm) and the dispersion with the bead mill disperser was changed to 12 times. Obtained a battery separator.
本発明のセパレータは、リチウムイオン電池などの非水電解質電池に好ましく用いられ
るバッテリー用セパレータとして好適に用いることができる。
The separator of the present invention can be suitably used as a battery separator preferably used for non-aqueous electrolyte batteries such as lithium ion batteries.
Claims (5)
The battery separator according to any one of claims 1 to 4, wherein the heat-resistant porous layer has a thickness of 0.5 μm or more and 4.0 μm or less.
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| CN117936947A (en) * | 2024-03-21 | 2024-04-26 | 广州鑫虹兴电子有限公司 | Solid electrolyte of lithium battery and preparation method thereof |
| CN117936947B (en) * | 2024-03-21 | 2024-05-31 | 广州鑫虹兴电子有限公司 | Solid electrolyte of lithium battery and preparation method thereof |
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| CN117936947A (en) * | 2024-03-21 | 2024-04-26 | 广州鑫虹兴电子有限公司 | Solid electrolyte of lithium battery and preparation method thereof |
| CN117936947B (en) * | 2024-03-21 | 2024-05-31 | 广州鑫虹兴电子有限公司 | Solid electrolyte of lithium battery and preparation method thereof |
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