JP7409132B2 - Nonaqueous electrolyte storage element - Google Patents
Nonaqueous electrolyte storage element Download PDFInfo
- Publication number
- JP7409132B2 JP7409132B2 JP2020021702A JP2020021702A JP7409132B2 JP 7409132 B2 JP7409132 B2 JP 7409132B2 JP 2020021702 A JP2020021702 A JP 2020021702A JP 2020021702 A JP2020021702 A JP 2020021702A JP 7409132 B2 JP7409132 B2 JP 7409132B2
- Authority
- JP
- Japan
- Prior art keywords
- negative electrode
- active material
- positive electrode
- aqueous electrolyte
- 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.)
- Active
Links
- 239000011255 nonaqueous electrolyte Substances 0.000 title claims description 95
- 238000003860 storage Methods 0.000 title claims description 75
- 239000000463 material Substances 0.000 claims description 51
- 239000007773 negative electrode material Substances 0.000 claims description 49
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 41
- 239000011230 binding agent Substances 0.000 claims description 29
- 229920000178 Acrylic resin Polymers 0.000 claims description 24
- 239000004925 Acrylic resin Substances 0.000 claims description 24
- 239000007774 positive electrode material Substances 0.000 claims description 24
- 229910002804 graphite Inorganic materials 0.000 claims description 21
- 239000010439 graphite Substances 0.000 claims description 21
- 230000035699 permeability Effects 0.000 claims description 17
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 claims description 10
- 239000010954 inorganic particle Substances 0.000 claims description 10
- 229920000098 polyolefin Polymers 0.000 claims description 6
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 2
- 230000003746 surface roughness Effects 0.000 claims 2
- 239000010410 layer Substances 0.000 description 71
- 230000014759 maintenance of location Effects 0.000 description 23
- 238000007600 charging Methods 0.000 description 20
- 230000007423 decrease Effects 0.000 description 15
- -1 etc. Substances 0.000 description 15
- 239000000203 mixture Substances 0.000 description 15
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 14
- 229910001416 lithium ion Inorganic materials 0.000 description 14
- 229910052744 lithium Inorganic materials 0.000 description 12
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 10
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 10
- 229910052799 carbon Inorganic materials 0.000 description 10
- 239000003575 carbonaceous material Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 10
- 239000006258 conductive agent Substances 0.000 description 9
- 150000003839 salts Chemical class 0.000 description 8
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 7
- 239000013078 crystal Substances 0.000 description 7
- 150000005676 cyclic carbonates Chemical class 0.000 description 7
- 239000002562 thickening agent Substances 0.000 description 7
- 229910052782 aluminium Inorganic materials 0.000 description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- 239000003990 capacitor Substances 0.000 description 6
- 150000005678 chain carbonates Chemical class 0.000 description 6
- 238000007599 discharging Methods 0.000 description 6
- 239000003792 electrolyte Substances 0.000 description 6
- 239000011888 foil Substances 0.000 description 6
- 229910003002 lithium salt Inorganic materials 0.000 description 6
- 159000000002 lithium salts Chemical class 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 5
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 5
- 239000003125 aqueous solvent Substances 0.000 description 5
- 239000011889 copper foil Substances 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 5
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 5
- 239000000945 filler Substances 0.000 description 5
- 239000011572 manganese Substances 0.000 description 5
- 239000011347 resin Substances 0.000 description 5
- 229920005989 resin Polymers 0.000 description 5
- 229920003048 styrene butadiene rubber Polymers 0.000 description 5
- 241000156302 Porcine hemagglutinating encephalomyelitis virus Species 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 239000006229 carbon black Substances 0.000 description 4
- 239000002612 dispersion medium Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000004146 energy storage Methods 0.000 description 4
- 150000002484 inorganic compounds Chemical class 0.000 description 4
- 229910010272 inorganic material Inorganic materials 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000002905 metal composite material Substances 0.000 description 4
- 230000002829 reductive effect Effects 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 229910052723 transition metal Inorganic materials 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910013870 LiPF 6 Inorganic materials 0.000 description 3
- 229910021314 NaFeO 2 Inorganic materials 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 239000006230 acetylene black Substances 0.000 description 3
- 229910021383 artificial graphite Inorganic materials 0.000 description 3
- 229910021393 carbon nanotube Inorganic materials 0.000 description 3
- 239000002041 carbon nanotube Substances 0.000 description 3
- 238000010280 constant potential charging Methods 0.000 description 3
- 238000010277 constant-current charging Methods 0.000 description 3
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 3
- 229910021389 graphene Inorganic materials 0.000 description 3
- 238000010030 laminating Methods 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 229910021470 non-graphitizable carbon Inorganic materials 0.000 description 3
- 229920000447 polyanionic polymer Polymers 0.000 description 3
- 229920000573 polyethylene Polymers 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 239000011029 spinel Substances 0.000 description 3
- 229910052596 spinel Inorganic materials 0.000 description 3
- ZZXUZKXVROWEIF-UHFFFAOYSA-N 1,2-butylene carbonate Chemical compound CCC1COC(=O)O1 ZZXUZKXVROWEIF-UHFFFAOYSA-N 0.000 description 2
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 description 2
- BJWMSGRKJIOCNR-UHFFFAOYSA-N 4-ethenyl-1,3-dioxolan-2-one Chemical compound C=CC1COC(=O)O1 BJWMSGRKJIOCNR-UHFFFAOYSA-N 0.000 description 2
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 229910021536 Zeolite Inorganic materials 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 125000004429 atom Chemical group 0.000 description 2
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Chemical compound [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 2
- 229910001593 boehmite Inorganic materials 0.000 description 2
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-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
- 150000001786 chalcogen compounds Chemical class 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- QXYJCZRRLLQGCR-UHFFFAOYSA-N dioxomolybdenum Chemical compound O=[Mo]=O QXYJCZRRLLQGCR-UHFFFAOYSA-N 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 239000011883 electrode binding agent Substances 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 229910021469 graphitizable carbon Inorganic materials 0.000 description 2
- 230000020169 heat generation Effects 0.000 description 2
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 229910021437 lithium-transition metal oxide Inorganic materials 0.000 description 2
- 239000012982 microporous membrane Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910021382 natural graphite Inorganic materials 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- 239000002006 petroleum coke Substances 0.000 description 2
- 239000011301 petroleum pitch Substances 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Chemical compound [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 239000010457 zeolite Substances 0.000 description 2
- JHPBZFOKBAGZBL-UHFFFAOYSA-N (3-hydroxy-2,2,4-trimethylpentyl) 2-methylprop-2-enoate Chemical compound CC(C)C(O)C(C)(C)COC(=O)C(C)=C JHPBZFOKBAGZBL-UHFFFAOYSA-N 0.000 description 1
- WFLOTYSKFUPZQB-UHFFFAOYSA-N 1,2-difluoroethene Chemical group FC=CF WFLOTYSKFUPZQB-UHFFFAOYSA-N 0.000 description 1
- NZPSDGIEKAQVEZ-UHFFFAOYSA-N 1,3-benzodioxol-2-one Chemical compound C1=CC=CC2=C1OC(=O)O2 NZPSDGIEKAQVEZ-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
- SROHGOJDCAODGI-UHFFFAOYSA-N 4,5-diphenyl-1,3-dioxol-2-one Chemical compound O1C(=O)OC(C=2C=CC=CC=2)=C1C1=CC=CC=C1 SROHGOJDCAODGI-UHFFFAOYSA-N 0.000 description 1
- OYOKPDLAMOMTEE-UHFFFAOYSA-N 4-chloro-1,3-dioxolan-2-one Chemical compound ClC1COC(=O)O1 OYOKPDLAMOMTEE-UHFFFAOYSA-N 0.000 description 1
- VMAJRFCXVOIAAS-UHFFFAOYSA-N 4-phenyl-1,3-dioxol-2-one Chemical compound O1C(=O)OC=C1C1=CC=CC=C1 VMAJRFCXVOIAAS-UHFFFAOYSA-N 0.000 description 1
- ZKOGUIGAVNCCKH-UHFFFAOYSA-N 4-phenyl-1,3-dioxolan-2-one Chemical compound O1C(=O)OCC1C1=CC=CC=C1 ZKOGUIGAVNCCKH-UHFFFAOYSA-N 0.000 description 1
- 239000005995 Aluminium silicate Substances 0.000 description 1
- XMWRBQBLMFGWIX-UHFFFAOYSA-N C60 fullerene Chemical compound C12=C3C(C4=C56)=C7C8=C5C5=C9C%10=C6C6=C4C1=C1C4=C6C6=C%10C%10=C9C9=C%11C5=C8C5=C8C7=C3C3=C7C2=C1C1=C2C4=C6C4=C%10C6=C9C9=C%11C5=C5C8=C3C3=C7C1=C1C2=C4C6=C2C9=C5C3=C12 XMWRBQBLMFGWIX-UHFFFAOYSA-N 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 229920008712 Copo Polymers 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910013063 LiBF 4 Inorganic materials 0.000 description 1
- 229910013684 LiClO 4 Inorganic materials 0.000 description 1
- 229910011281 LiCoPO 4 Inorganic materials 0.000 description 1
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 1
- 229910013131 LiN Inorganic materials 0.000 description 1
- 229910013528 LiN(SO2 CF3)2 Inorganic materials 0.000 description 1
- 229910013392 LiN(SO2CF3)(SO2C4F9) Inorganic materials 0.000 description 1
- 229910002991 LiNi0.5Co0.2Mn0.3O2 Inorganic materials 0.000 description 1
- 229910013086 LiNiPO Inorganic materials 0.000 description 1
- 229910012258 LiPO Inorganic materials 0.000 description 1
- 229910012424 LiSO 3 Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- KFDQGLPGKXUTMZ-UHFFFAOYSA-N [Mn].[Co].[Ni] Chemical compound [Mn].[Co].[Ni] KFDQGLPGKXUTMZ-UHFFFAOYSA-N 0.000 description 1
- YKTSYUJCYHOUJP-UHFFFAOYSA-N [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] Chemical compound [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] YKTSYUJCYHOUJP-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910000323 aluminium silicate Inorganic materials 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 150000001450 anions Chemical group 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
- OYLGJCQECKOTOL-UHFFFAOYSA-L barium fluoride Chemical compound [F-].[F-].[Ba+2] OYLGJCQECKOTOL-UHFFFAOYSA-L 0.000 description 1
- 229910001632 barium fluoride Inorganic materials 0.000 description 1
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 1
- 229910002113 barium titanate Inorganic materials 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
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 239000002134 carbon nanofiber Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 238000003795 desorption Methods 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
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- ROORDVPLFPIABK-UHFFFAOYSA-N diphenyl carbonate Chemical compound C=1C=CC=CC=1OC(=O)OC1=CC=CC=C1 ROORDVPLFPIABK-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- 229910003472 fullerene Inorganic materials 0.000 description 1
- 239000006232 furnace black Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000004676 glycans Chemical class 0.000 description 1
- 150000002430 hydrocarbons Chemical group 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 239000002608 ionic liquid Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 150000002596 lactones Chemical class 0.000 description 1
- 239000005001 laminate film Substances 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 159000000003 magnesium salts Chemical class 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical class C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 229920000609 methyl cellulose Polymers 0.000 description 1
- 230000011987 methylation Effects 0.000 description 1
- 238000007069 methylation reaction Methods 0.000 description 1
- 239000001923 methylcellulose Substances 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 1
- 229910052982 molybdenum disulfide Inorganic materials 0.000 description 1
- 238000012806 monitoring device Methods 0.000 description 1
- 229910052901 montmorillonite Inorganic materials 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000033116 oxidation-reduction process Effects 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
- 238000012856 packing Methods 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
- 230000000704 physical effect Effects 0.000 description 1
- 239000011295 pitch Substances 0.000 description 1
- 229920002401 polyacrylamide Polymers 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920001282 polysaccharide Polymers 0.000 description 1
- 239000005017 polysaccharide Substances 0.000 description 1
- 159000000001 potassium salts Chemical class 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 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
- 159000000000 sodium salts Chemical class 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 150000003457 sulfones Chemical class 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- CFJRPNFOLVDFMJ-UHFFFAOYSA-N titanium disulfide Chemical compound S=[Ti]=S CFJRPNFOLVDFMJ-UHFFFAOYSA-N 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
- 229910001928 zirconium oxide Inorganic materials 0.000 description 1
Images
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
Description
本発明は、非水電解質蓄電素子に関する。 The present invention relates to a non-aqueous electrolyte storage device.
リチウムイオン非水電解質二次電池に代表される非水電解質二次電池は、エネルギー密度の高さから、パーソナルコンピュータ、通信端末等の電子機器、自動車等に多用されている。上記非水電解質二次電池は、一般的には、セパレータで電気的に隔離された一対の電極を有する電極体、及び電極間に介在する非水電解質を備え、両電極間でイオンの受け渡しを行うことで充放電するよう構成される。また、非水電解質二次電池以外の蓄電素子として、リチウムイオンキャパシタや電気二重層キャパシタ等のキャパシタも広く普及している。 Nonaqueous electrolyte secondary batteries, typified by lithium ion nonaqueous electrolyte secondary batteries, have high energy density and are widely used in electronic devices such as personal computers and communication terminals, automobiles, and the like. The non-aqueous electrolyte secondary battery generally includes an electrode body having a pair of electrodes electrically isolated by a separator, and a non-aqueous electrolyte interposed between the electrodes, and transfers ions between the two electrodes. It is configured to charge and discharge by doing so. Furthermore, capacitors such as lithium ion capacitors and electric double layer capacitors are also widely used as power storage elements other than non-aqueous electrolyte secondary batteries.
このような蓄電素子のエネルギー密度の向上などを目的として上記蓄電素子の負極活物質としては、黒鉛をはじめとする炭素材料が用いられている（特許文献１参照）。 Carbon materials such as graphite are used as negative electrode active materials of the above-mentioned power storage elements for the purpose of improving the energy density of such power storage elements (see Patent Document 1).
上記自動車等のエネルギー源としては、急速充電性能を有する非水電解質二次電池が求められている。しかしながら、上記負極活物質として黒鉛を用いた非水電解質二次電池について急速充電を行った場合、負極電位が卑であることに起因して非水電解質の分解反応が促進され、急速充放電サイクル（ハイレートサイクル）時の容量維持率が低下するおそれがある。 Non-aqueous electrolyte secondary batteries with rapid charging performance are required as an energy source for the above-mentioned automobiles and the like. However, when rapid charging is performed on a non-aqueous electrolyte secondary battery using graphite as the negative electrode active material, the decomposition reaction of the non-aqueous electrolyte is accelerated due to the negative electrode potential being base, resulting in a rapid charge-discharge cycle. There is a risk that the capacity retention rate during (high rate cycle) may decrease.
本発明は、以上のような事情に基づいてなされたものであり、急速充放電サイクル時の容量維持率の低下を抑制できる非水電解質蓄電素子を提供することを目的とする。 The present invention has been made based on the above circumstances, and an object of the present invention is to provide a non-aqueous electrolyte storage element that can suppress a decrease in capacity retention during rapid charge/discharge cycles.
本発明の一側面に係る非水電解質蓄電素子は、正極と、負極と、上記正極及び上記負極間に介在するセパレータとを備えており、上記負極が黒鉛及びアクリル樹脂を含む負極活物質層を有し、上記セパレータの透気度が２００［秒／１００ｃｍ３］以下である。 A nonaqueous electrolyte storage device according to one aspect of the present invention includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and the negative electrode has a negative electrode active material layer containing graphite and an acrylic resin. The separator has an air permeability of 200 [sec/100 cm 3 ] or less.
本発明の一側面に係る非水電解質蓄電素子は、急速充放電サイクル時の容量維持率の低下を抑制できる。 The non-aqueous electrolyte storage element according to one aspect of the present invention can suppress a decrease in capacity retention rate during rapid charge/discharge cycles.
本発明の一側面に係る非水電解質蓄電素子は、正極と、負極と、上記正極及び上記負極間に介在するセパレータとを備えており、上記負極が黒鉛及びアクリル樹脂を含む負極活物質層を有し、上記セパレータの透気度が２００［秒／１００ｃｍ３］以下である。 A nonaqueous electrolyte storage device according to one aspect of the present invention includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and the negative electrode has a negative electrode active material layer containing graphite and an acrylic resin. The separator has an air permeability of 200 [sec/100 cm 3 ] or less.
非水電解質蓄電素子に用いられる負極材料としては、リチウムの酸化還元電位に近い卑な電位における単位質量あたりの充放電容量の大きい黒鉛が広く用いられ、負極用バインダーとしては、比較的少ない添加量で利用可能なスチレンブタジエンゴムが広く用いられている。一方、本発明者らは、非水電解質蓄電素子の負極活物質層が負極活物質としての黒鉛と、バインダーとしてのアクリル樹脂とを含み、上記正極及び上記負極間に介在するセパレータの透気度が２００［秒／１００ｃｍ３］以下であることで、非水電解質蓄電素子の急速充放電サイクル時の容量維持率の低下を抑制できることを知見した。この理由は定かではないが、次のように考えられる。負極活物質として黒鉛を含む負極では、リチウムイオン等の金属イオンの挿入脱離の電位が非常に卑であることに加え、急速充電をおこなうと分極の影響も加わるため、さらに負極電位が卑となり、非水電解質の還元分解がより促進される。この結果、急速充放電サイクル時の容量維持率が低下する場合があると考えられる。バインダーとしてアクリル樹脂を用いた負極は、バインダーとしてスチレンブタジエンゴムを用いた負極と比較して抵抗が低い。そのため、バインダーにアクリル樹脂を用いた負極では、急速充電時の分極が小さくなることにより、負極電位が比較的に卑になりにくく、非水電解質の分解が抑制される。しかしながら、バインダーにアクリル樹脂を用いた負極と、透気度が大きく、緊密性が高いセパレータとを組み合わせた場合、急速充電時に負極に対するリチウムイオン等の供給が追いつかなくなり、急速充放電サイクルを重ねていくと、放電容量維持率が低下する傾向があることを発明者らは見出した。従って、当該非水電解質蓄電素子は、バインダーとしてアクリル樹脂を用いた負極と透気度が２００［秒／１００ｃｍ３］以下のセパレータとを組み合わせることで、急速充電時に負極に対して十分なリチウムイオンを供給することができる。その結果、当該非水電解質蓄電素子は、急速充放電サイクル時の容量維持率の低下を抑制できると推測される。ここで、「透気度」は、ガーレ値ともいい、一定圧力差のもとで一定体積の空気が一定面積の紙を通過する秒数を示し、ＪＩＳ－Ｐ８１１７（２００９）に準拠して測定される値である。 Graphite, which has a large charge/discharge capacity per unit mass at a base potential close to the oxidation-reduction potential of lithium, is widely used as the negative electrode material used in non-aqueous electrolyte storage devices, and as a binder for the negative electrode, it can be added in a relatively small amount. Styrene-butadiene rubber, which is available in On the other hand, the present inventors have discovered that the negative electrode active material layer of the non-aqueous electrolyte storage element contains graphite as the negative electrode active material and acrylic resin as the binder, and that the air permeability of the separator interposed between the positive electrode and the negative electrode is It has been found that when the ratio is 200 [sec/100 cm 3 ] or less, it is possible to suppress a decrease in the capacity retention rate of the non-aqueous electrolyte storage element during rapid charge/discharge cycles. Although the reason for this is not certain, it is thought to be as follows. In a negative electrode containing graphite as the negative electrode active material, the potential for intercalation and desorption of metal ions such as lithium ions is very base, and when rapid charging is performed, the effect of polarization is added, so the negative electrode potential becomes even more base. , the reductive decomposition of non-aqueous electrolytes is further promoted. As a result, it is thought that the capacity retention rate during rapid charge/discharge cycles may decrease. A negative electrode using acrylic resin as a binder has lower resistance than a negative electrode using styrene-butadiene rubber as a binder. Therefore, in a negative electrode using an acrylic resin as a binder, the polarization during rapid charging is reduced, so that the negative electrode potential is relatively less likely to become base, and decomposition of the nonaqueous electrolyte is suppressed. However, when a negative electrode using acrylic resin as a binder is combined with a separator that has high air permeability and high tightness, the supply of lithium ions, etc. to the negative electrode cannot keep up with the negative electrode during rapid charging, resulting in repeated rapid charge/discharge cycles. The inventors discovered that the discharge capacity retention rate tends to decrease as the discharge capacity increases. Therefore, by combining a negative electrode using acrylic resin as a binder and a separator with an air permeability of 200 [sec/100 cm 3 ] or less, the non-aqueous electrolyte storage element can provide sufficient lithium ions to the negative electrode during rapid charging. can be supplied. As a result, it is presumed that the non-aqueous electrolyte storage element can suppress a decrease in capacity retention rate during rapid charge/discharge cycles. Here, "air permeability" is also called Gurley value, and indicates the number of seconds for a certain volume of air to pass through a certain area of paper under a certain pressure difference, and is measured in accordance with JIS-P8117 (2009). is the value to be used.
上記アクリル樹脂がブタジエンに由来する構造単位を有さないことが好ましい。上記アクリル樹脂がブタジエンに由来する構造単位を有さないことで、初期の抵抗を低減できるとともに、急速充放電サイクル時の容量維持率の低下をより抑制することができる。 It is preferable that the acrylic resin does not have a structural unit derived from butadiene. Since the acrylic resin does not have a structural unit derived from butadiene, initial resistance can be reduced, and a decrease in capacity retention rate during rapid charge/discharge cycles can be further suppressed.
上記セパレータが微多孔膜状の基材層を有し、上記基材層の主成分がポリオレフィンであることが好ましい。上記構成により、意図しない理由で短絡等による過剰な発熱が生じた場合であっても、電流のシャットダウン機能が働き、短絡電流の増大を抑制することができるため、高い安全性を備えることができる。 It is preferable that the separator has a base layer in the form of a microporous membrane, and that the main component of the base layer is polyolefin. With the above configuration, even if excessive heat generation occurs due to an unintended reason such as a short circuit, the current shutdown function is activated and the increase in short circuit current can be suppressed, resulting in a high level of safety. .
上記セパレータが耐熱層を有し、上記耐熱層が無機粒子及びバインダーを含むことが好ましい。上記セパレータが無機粒子及びバインダーを含む耐熱層を有することで、意図しない理由で蓄電素子の温度が過剰に上昇した場合にもセパレータの破損を抑制して正極と負極との短絡をより確実に抑制するとともに、セパレータの形状維持を図ることができる。さらに、無機粒子及びバインダーを含む耐熱層を有することで、セパレータの形状維持性が高くなるため、セパレータ又は基材層の空孔率を高くし、セパレータの透気度を十分に低くすることが可能となる。 It is preferable that the separator has a heat-resistant layer, and the heat-resistant layer contains inorganic particles and a binder. Since the separator has a heat-resistant layer containing inorganic particles and a binder, even if the temperature of the electricity storage element rises excessively due to unintended reasons, damage to the separator is suppressed and short circuits between the positive electrode and the negative electrode are more reliably suppressed. At the same time, the shape of the separator can be maintained. Furthermore, having a heat-resistant layer containing inorganic particles and a binder increases the shape retention of the separator, so it is possible to increase the porosity of the separator or base material layer and make the air permeability of the separator sufficiently low. It becomes possible.
以下、本発明の一実施形態に係る非水電解質蓄電素子について詳説する。
＜非水電解質蓄電素子＞
本発明の一実施形態に係る非水電解質蓄電素子は、正極と、負極と、上記正極及び上記負極間に介在するセパレータと、非水電解質とを備えている。以下、非水電解質蓄電素子の好ましい一例として、非水電解質二次電池について説明する。上記正極及び負極は、通常、セパレータを介して積層又は巻回により交互に重畳された電極体を形成する。この電極体はケースに収納され、このケース内に非水電解質が充填される。上記非水電解質は、正極と負極との間に介在する。また、上記ケースとしては、非水電解質二次電池のケースとして通常用いられる公知の金属ケース、樹脂ケース等を用いることができる。
Hereinafter, a non-aqueous electrolyte storage device according to an embodiment of the present invention will be explained in detail.
<Nonaqueous electrolyte storage element>
A non-aqueous electrolyte storage device according to an embodiment of the present invention includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte. Hereinafter, a non-aqueous electrolyte secondary battery will be described as a preferable example of a non-aqueous electrolyte storage element. The above-mentioned positive electrode and negative electrode usually form an electrode body in which they are alternately stacked by stacking or winding with a separator in between. This electrode body is housed in a case, and the case is filled with a nonaqueous electrolyte. The non-aqueous electrolyte is interposed between the positive electrode and the negative electrode. Further, as the case, a known metal case, resin case, etc. that are commonly used as cases for non-aqueous electrolyte secondary batteries can be used.
［負極］
負極は、負極基材と、負極活物質層とを有する。上記負極活物質層は、負極活物質を含有する。上記負極活物質層は、上記負極基材の少なくとも一方の面の表面に直接又は中間層を介して積層される。
[Negative electrode]
The negative electrode includes a negative electrode base material and a negative electrode active material layer. The negative electrode active material layer contains a negative electrode active material. The negative electrode active material layer is laminated directly or via an intermediate layer on at least one surface of the negative electrode base material.
（負極基材）
上記負極基材は、導電性を有する基材である。負極基材の材質としては、銅、ニッケル、ステンレス鋼、ニッケルメッキ鋼等の金属又はそれらの合金が用いられ、銅又は銅合金が好ましい。また、負極基材の形態としては、箔、蒸着膜等が挙げられ、コストの面から箔が好ましい。つまり、負極基材としては銅箔が好ましい。銅箔としては、圧延銅箔、電解銅箔等が例示される。なお、「導電性」を有するとは、ＪＩＳ－Ｈ－０５０５（１９７５年）に準拠して測定される体積抵抗率が１×１０７Ω・ｃｍ以下であることを意味し、「非導電性」とは、上記体積抵抗率が１×１０７Ω・ｃｍ超であることを意味する。
(Negative electrode base material)
The negative electrode base material is a conductive base material. As the material of the negative electrode base material, metals such as copper, nickel, stainless steel, nickel-plated steel, or alloys thereof are used, and copper or copper alloys are preferable. In addition, examples of the form of the negative electrode base material include foil, vapor deposited film, etc., and foil is preferable from the viewpoint of cost. In other words, copper foil is preferable as the negative electrode base material. Examples of the copper foil include rolled copper foil, electrolytic copper foil, and the like. Note that "conductive" means that the volume resistivity measured in accordance with JIS-H-0505 (1975) is 1 x 10 7 Ω・cm or less, and "non-conductive" ” means that the volume resistivity is more than 1×10 7 Ω·cm.
（負極活物質層）
負極活物質層は、負極活物質を含むいわゆる負極合剤から形成される。負極活物質層は、黒鉛及びアクリル樹脂を含む。
(Negative electrode active material layer)
The negative electrode active material layer is formed from a so-called negative electrode mixture containing a negative electrode active material. The negative electrode active material layer contains graphite and acrylic resin.
当該非水電解質蓄電素子は、負極活物質として黒鉛（グラファイト）を含む。負極活物質として黒鉛を含むことで、エネルギー密度を高めることができる。黒鉛としては、天然黒鉛、人造黒鉛が挙げられる。負極活物質として黒鉛を含む場合、負極活物質表面上でのリチウムイオンの移動速度が遅いために、負極表層でのリチウム濃度が高くなる。その結果、負極表面上での非水電解質の分解反応が促進され、急速充放電サイクル時の容量維持率が低下しやすくなる。一方、難黒鉛化性炭素等の非黒鉛質炭素は、充放電時の電位が緩やかに変化することから、負極活物質層中のリチウム濃度が緩和されやすいと考えられる。そのため、負極表層中のリチウム濃度が高くなることはなく、過度な非水電解質の分解反応を抑制できるために、急速充放電サイクル時の容量維持率は低下しにくいと推測される。従って、当該非水電解質蓄電素子は、黒鉛を含む負極活物質層を有する負極特有の課題に対して効果を奏するものである。 The non-aqueous electrolyte storage element contains graphite as a negative electrode active material. By including graphite as a negative electrode active material, energy density can be increased. Examples of graphite include natural graphite and artificial graphite. When graphite is included as the negative electrode active material, the movement speed of lithium ions on the surface of the negative electrode active material is slow, so the lithium concentration in the negative electrode surface layer becomes high. As a result, the decomposition reaction of the nonaqueous electrolyte on the surface of the negative electrode is promoted, and the capacity retention rate during rapid charge/discharge cycles tends to decrease. On the other hand, with non-graphitic carbon such as non-graphitizable carbon, the potential during charging and discharging changes slowly, so it is thought that the lithium concentration in the negative electrode active material layer is likely to be relaxed. Therefore, the lithium concentration in the negative electrode surface layer does not become high, and excessive decomposition reaction of the nonaqueous electrolyte can be suppressed, so it is presumed that the capacity retention rate during rapid charge/discharge cycles is unlikely to decrease. Therefore, the non-aqueous electrolyte storage element is effective in solving problems specific to negative electrodes having a negative electrode active material layer containing graphite.
「黒鉛」とは、充放電前又は放電状態において、Ｘ線回折法により決定される（００２）面の平均格子面間隔（ｄ００２）が０．３３ｎｍ以上０．３４ｎｍ未満の炭素材料をいう。黒鉛としては、天然黒鉛、人造黒鉛が挙げられる。安定した物性の材料を入手できるという観点で、人造黒鉛が好ましい。 "Graphite" refers to a carbon material having an average lattice spacing (d 002 ) of the (002) plane of 0.33 nm or more and less than 0.34 nm before charging and discharging or in a discharge state, as determined by X-ray diffraction. Examples of graphite include natural graphite and artificial graphite. Artificial graphite is preferred from the viewpoint of being able to obtain a material with stable physical properties.
「非黒鉛質炭素」とは、充放電前又は放電状態においてＸ線回折法により決定される（００２）面の平均格子面間隔（ｄ００２）が０．３４ｎｍ以上０．４２ｎｍ以下の炭素材料をいう。非黒鉛質炭素としては、難黒鉛化性炭素や、易黒鉛化性炭素が挙げられる。非黒鉛質炭素としては、例えば、樹脂由来の材料、石油ピッチ又は石油ピッチ由来の材料、石油コークス又は石油コークス由来の材料、植物由来の材料、アルコール由来の材料等が挙げられる。「難黒鉛化性炭素」とは、上記ｄ００２が０．３６ｎｍ以上０．４２ｎｍ以下の炭素材料をいう。「易黒鉛化性炭素」とは、上記ｄ００２が０．３４ｎｍ以上０．３６ｎｍ未満の炭素材料をいう。 "Non-graphitic carbon" refers to a carbon material whose average lattice spacing (d 002 ) of the (002) plane is 0.34 nm or more and 0.42 nm or less, as determined by X-ray diffraction before charging and discharging or in a discharge state. say. Examples of non-graphitic carbon include non-graphitizable carbon and easily graphitizable carbon. Examples of the non-graphitic carbon include resin-derived materials, petroleum pitch or petroleum pitch-derived materials, petroleum coke or petroleum coke-derived materials, plant-derived materials, alcohol-derived materials, and the like. "Non-graphitizable carbon" refers to a carbon material in which the above d 002 is 0.36 nm or more and 0.42 nm or less. "Graphitizable carbon" refers to a carbon material in which the above d 002 is 0.34 nm or more and less than 0.36 nm.
ここで、「放電状態」とは、負極活物質として炭素材料を含む負極を作用極として、金属リチウムを対極として用いた単極電池において、開回路電圧が０．７Ｖ以上である状態をいう。開回路状態での金属リチウム対極の電位は、リチウムの酸化還元電位とほぼ等しいため、上記単極電池における開回路電圧は、リチウムの酸化還元電位に対する炭素材料を含む負極の電位とほぼ同等である。つまり、上記単極電池における開回路電圧が０．７Ｖ以上であることは、負極活物質である炭素材料から、充放電に伴い吸蔵放出可能なリチウムイオンが十分に放出されていることを意味する。 Here, the "discharge state" refers to a state in which the open circuit voltage is 0.7 V or more in a monopolar battery using a negative electrode containing a carbon material as a negative electrode active material as a working electrode and metallic lithium as a counter electrode. Since the potential of the metallic lithium counter electrode in an open circuit state is approximately equal to the redox potential of lithium, the open circuit voltage in the above-mentioned monopolar battery is approximately equivalent to the potential of the negative electrode containing the carbon material relative to the redox potential of lithium. . In other words, if the open circuit voltage of the monopolar battery is 0.7 V or more, it means that a sufficient amount of lithium ions, which can be intercalated and released during charging and discharging, is released from the carbon material that is the negative electrode active material. .
負極活物質中の黒鉛の含有量の下限としては、６０質量％が好ましく、７０質量％がより好ましく、８０質量％がさらに好ましい。一方、この含有量の上限としては、１００質量％が好ましく、９５質量％がより好ましい。 The lower limit of the graphite content in the negative electrode active material is preferably 60% by mass, more preferably 70% by mass, and even more preferably 80% by mass. On the other hand, the upper limit of this content is preferably 100% by mass, more preferably 95% by mass.
負極活物質層中の負極活物質の含有量は特に限定されないが、その下限としては、５０質量％が好ましく、８０質量％がより好ましく、９０質量％がさらに好ましい。一方、この含有量の上限としては、９９質量％が好ましく、９８質量％がより好ましい。 The content of the negative electrode active material in the negative electrode active material layer is not particularly limited, but its lower limit is preferably 50% by mass, more preferably 80% by mass, and even more preferably 90% by mass. On the other hand, the upper limit of this content is preferably 99% by mass, more preferably 98% by mass.
（バインダー）
当該非水電解質蓄電素子の負極合剤は、バインダーとしてアクリル樹脂を含む。「アクリル樹脂」とは、ポリアクリル酸が除かれ、例えばアクリル酸エステル、メタクリル酸又はメタクリル酸エステルの重合体、ポリアクリルアミド、アクリル酸を含む共重合体等が挙げられる。
(binder)
The negative electrode mixture of the non-aqueous electrolyte storage element contains an acrylic resin as a binder. "Acrylic resin" excludes polyacrylic acid, and includes, for example, acrylic ester, methacrylic acid or a polymer of methacrylic ester, polyacrylamide, a copolymer containing acrylic acid, and the like.
上記アクリル樹脂がブタジエンに由来する構造単位を有さないことが好ましい。上記アクリル樹脂がブタジエンに由来する構造単位を有さないことで、初期の抵抗を低減できる。 It is preferable that the acrylic resin does not have a structural unit derived from butadiene. Since the acrylic resin does not have a structural unit derived from butadiene, initial resistance can be reduced.
上記バインダーにおけるアクリル樹脂の含有量としては、９９質量％以上が好ましく、１００質量％であってもよい。 The content of the acrylic resin in the binder is preferably 99% by mass or more, and may be 100% by mass.
負極活物質層中のバインダーの含有量の下限としては、０．２質量％が好ましく、０．５質量％がより好ましく、１質量％がさらに好ましい。一方、この含有量の上限としては、１０質量％が好ましく、５質量％がより好ましい。 The lower limit of the binder content in the negative electrode active material layer is preferably 0.2% by mass, more preferably 0.5% by mass, and even more preferably 1% by mass. On the other hand, the upper limit of this content is preferably 10% by mass, more preferably 5% by mass.
（その他の任意成分）
負極合剤は、必要に応じて導電剤、増粘剤、フィラー等の任意成分を含む。
(Other optional ingredients)
The negative electrode mixture contains optional components such as a conductive agent, a thickener, and a filler, as necessary.
上記導電剤としては、導電性材料であれば特に限定されない。このような導電剤としては、上記黒鉛も導電性を有するが、例えば、炭素質材料、金属、導電性セラミックス等が挙げられる。炭素質材料としては、非黒鉛化炭素、グラフェン系炭素等が挙げられる。非黒鉛化炭素としては、カーボンナノファイバー、ピッチ系炭素繊維、カーボンブラック等が挙げられる。カーボンブラックとしては、ファーネスブラック、アセチレンブラック、ケッチェンブラック等が挙げられる。グラフェン系炭素としては、グラフェン、カーボンナノチューブ（ＣＮＴ）、フラーレン等が挙げられる。導電剤の形状としては、粉状、繊維状等が挙げられる。導電剤としては、これらの材料の１種を単独で用いてもよく、２種以上を混合して用いてもよい。また、これらの材料を複合化して用いてもよい。例えば、カーボンブラックとＣＮＴとを複合化した材料を用いてもよい。これらの中でも、電子伝導性及び塗工性の観点よりカーボンブラックが好ましく、中でもアセチレンブラックが好ましい。 The conductive agent is not particularly limited as long as it is a conductive material. Examples of such a conductive agent include carbonaceous materials, metals, conductive ceramics, etc., although the graphite described above also has conductivity. Examples of the carbonaceous material include non-graphitized carbon, graphene-based carbon, and the like. Examples of non-graphitized carbon include carbon nanofibers, pitch-based carbon fibers, carbon black, and the like. Examples of carbon black include furnace black, acetylene black, Ketjen black, and the like. Examples of graphene-based carbon include graphene, carbon nanotubes (CNT), and fullerene. Examples of the shape of the conductive agent include powder, fiber, and the like. As the conductive agent, one type of these materials may be used alone, or two or more types may be used in combination. Further, these materials may be used in combination. For example, a composite material of carbon black and CNT may be used. Among these, carbon black is preferred from the viewpoint of electronic conductivity and coatability, and acetylene black is particularly preferred.
上記増粘剤としては、カルボキシメチルセルロース（ＣＭＣ）、メチルセルロース等の多糖類高分子が挙げられる。また、増粘剤がリチウムと反応する官能基を有する場合、予めメチル化等によりこの官能基を失活させておくことが好ましい。 Examples of the thickener include polysaccharide polymers such as carboxymethylcellulose (CMC) and methylcellulose. Further, when the thickener has a functional group that reacts with lithium, it is preferable to deactivate this functional group by methylation or the like in advance.
上記フィラーとしては、特に限定されない。フィラーの主成分としては、ポリプロピレン、ポリエチレン等のポリオレフィン、シリカ、アルミナ、ゼオライト、ガラス等が挙げられる。 The filler is not particularly limited. Main components of the filler include polyolefins such as polypropylene and polyethylene, silica, alumina, zeolite, and glass.
負極活物質層の目付量（負極における負極活物質層の単位面積当たりの質量）の下限としては、０．３ｍｇ／１００ｃｍ２が好ましく、０．４ｇ／１００ｃｍ２がより好ましい。一方、この目付量の上限としては、２．０ｇ／１００ｃｍ２が好ましく、１．５ｇ／１００ｃｍ２がより好ましい。負極活物質層の目付量が上記範囲であることで、高いエネルギー密度を有し、急速充放電サイクル時の容量維持率が高い非水電解質蓄電素子を得ることができる。 The lower limit of the basis weight of the negative electrode active material layer (mass per unit area of the negative electrode active material layer in the negative electrode) is preferably 0.3 mg/100 cm 2 , more preferably 0.4 g/100 cm 2 . On the other hand, the upper limit of this basis weight is preferably 2.0 g/100 cm 2 , more preferably 1.5 g/100 cm 2 . When the basis weight of the negative electrode active material layer is within the above range, it is possible to obtain a nonaqueous electrolyte storage element that has a high energy density and a high capacity retention rate during rapid charge/discharge cycles.
（中間層）
上記中間層は、負極基材の表面の被覆層であり、炭素粒子等の導電性粒子を含むことで負極基材と負極活物質層との接触抵抗を低減する。中間層の構成は特に限定されず、例えば樹脂バインダー及び導電性粒子を含有する組成物により形成できる。
(middle class)
The intermediate layer is a coating layer on the surface of the negative electrode base material, and contains conductive particles such as carbon particles to reduce contact resistance between the negative electrode base material and the negative electrode active material layer. The structure of the intermediate layer is not particularly limited, and can be formed, for example, from a composition containing a resin binder and conductive particles.
［正極］
正極は、正極基材と、正極活物質層とを有する。上記正極活物質層は、正極活物質を含有する。上記正極活物質層は、上記正極基材の少なくとも一方の面の表面に直接又は中間層を介して積層される。
[Positive electrode]
The positive electrode has a positive electrode base material and a positive electrode active material layer. The positive electrode active material layer contains a positive electrode active material. The positive electrode active material layer is laminated directly or via an intermediate layer on at least one surface of the positive electrode base material.
（正極基材）
上記正極基材は、導電性を有する基材である。正極基材の材質としては、アルミニウム、チタン、タンタル、ステンレス鋼等の金属又はそれらの合金が用いられる。これらの中でも、耐電位性、導電性の高さ及びコストのバランスからアルミニウム及びアルミニウム合金が好ましい。また、正極基材の形態としては、箔、蒸着膜等が挙げられ、コストの面から箔が好ましい。つまり、正極基材としてはアルミニウム箔が好ましい。なお、アルミニウム又はアルミニウム合金としては、ＪＩＳ－Ｈ４０００（２０１４）又はＪＩＳ－Ｈ－４１６０（２００６）に規定されるＡ１０８５、Ａ３００３、Ａ１Ｎ３０等が例示できる。
(Positive electrode base material)
The positive electrode base material is a conductive base material. As the material of the positive electrode base material, metals such as aluminum, titanium, tantalum, stainless steel, or alloys thereof are used. Among these, aluminum and aluminum alloys are preferred from the viewpoint of potential resistance, high conductivity, and cost balance. In addition, examples of the form of the positive electrode base material include foil, vapor deposited film, etc., and foil is preferable from the viewpoint of cost. That is, aluminum foil is preferable as the positive electrode base material. Note that examples of aluminum or aluminum alloy include A1085, A3003, A1N30, etc. defined in JIS-H4000 (2014) or JIS-H-4160 (2006).
（正極活物質層）
正極活物質層は、正極活物質を含むいわゆる正極合剤から形成される。上記正極活物質としては、例えば、公知の正極活物質の中から適宜選択できる。リチウムイオン二次電池用の正極活物質としては、通常、リチウムイオンを吸蔵及び放出することができる材料が用いられる。正極活物質としては、例えば、α－ＮａＦｅＯ２型結晶構造を有するリチウム遷移金属複合酸化物、スピネル型結晶構造を有するリチウム遷移金属酸化物、ポリアニオン化合物、カルコゲン化合物、硫黄等が挙げられる。α－ＮａＦｅＯ２型結晶構造を有するリチウム遷移金属複合酸化物として、例えば、Ｌｉ［ＬｉｘＮｉ１－ｘ］Ｏ２（０≦ｘ＜０．５）、Ｌｉ［ＬｉｘＮｉγＣｏ（１－ｘ－γ）］Ｏ２（０≦ｘ＜０．５、０＜γ＜１）、Ｌｉ［ＬｉｘＣｏ（１－ｘ）］Ｏ２（０≦ｘ＜０．５）、Ｌｉ［ＬｉｘＮｉγＭｎ（１－ｘ－γ）］Ｏ２（０≦ｘ＜０．５、０＜γ＜１）、Ｌｉ［ＬｉｘＮｉγＭｎβＣｏ（１－ｘ－γ－β）］Ｏ２（０≦ｘ＜０．５、０＜γ、０＜β、０．５＜γ＋β＜１）、Ｌｉ［ＬｉｘＮｉγＣｏβＡｌ（１－ｘ－γ－β）］Ｏ２（０≦ｘ＜０．５、０＜γ、０＜β、０．５＜γ＋β＜１）等が挙げられる。スピネル型結晶構造を有するリチウム遷移金属酸化物として、ＬｉｘＭｎ２Ｏ４，ＬｉｘＮｉγＭｎ（２－γ）Ｏ４等が挙げられる。ポリアニオン化合物として、ＬｉＦｅＰＯ４、ＬｉＭｎＰＯ４、ＬｉＮｉＰＯ４、ＬｉＣｏＰＯ４、Ｌｉ３Ｖ２（ＰＯ４）３、Ｌｉ２ＭｎＳｉＯ４、Ｌｉ２ＣｏＰＯ４Ｆ等が挙げられる。カルコゲン化合物として、二硫化チタン、二硫化モリブデン、二酸化モリブデン等が挙げられる。これらの材料中の原子又はポリアニオンは、他の元素からなる原子又はアニオン種で一部が置換されていてもよい。上記正極活物質としては、これらの中でも、高エネルギー密度化の観点から上記リチウム遷移金属複合酸化物が好ましく、リチウム以外に、ニッケル、コバルト及びマンガンを構成元素として含むニッケルコバルトマンガン含有リチウム遷移金属複合酸化物がより好ましい。
(Positive electrode active material layer)
The positive electrode active material layer is formed from a so-called positive electrode mixture containing a positive electrode active material. The positive electrode active material can be appropriately selected from known positive electrode active materials, for example. As a positive electrode active material for a lithium ion secondary battery, a material that can insert and release lithium ions is usually used. Examples of the positive electrode active material include a lithium transition metal composite oxide having an α-NaFeO 2 type crystal structure, a lithium transition metal oxide having a spinel type crystal structure, a polyanion compound, a chalcogen compound, and sulfur. Examples of lithium transition metal composite oxides having α-NaFeO 2 type crystal structure include Li[Li x Ni 1-x ]O 2 (0≦x<0.5), Li[Li x Ni γ Co (1- x-γ) ]O 2 (0≦x<0.5, 0<γ<1), Li[Li x Co (1-x) ]O 2 (0≦x<0.5), Li[Li x Ni γ Mn (1-x-γ) ]O 2 (0≦x<0.5, 0<γ<1), Li[Li x Ni γ Mn β Co (1-x-γ-β) ]O 2 (0≦x<0.5, 0<γ, 0<β, 0.5<γ+β<1), Li[Li x Ni γ Co β Al (1-x-γ-β) ]O 2 (0≦ Examples include x<0.5, 0<γ, 0<β, 0.5<γ+β<1). Lithium transition metal oxides having a spinel crystal structure include Li x Mn 2 O 4 , Li x Ni γ Mn (2-γ) O 4 and the like. Examples of the polyanion compound include LiFePO 4 , LiMnPO 4 , LiNiPO 4 , LiCoPO 4 , Li 3 V 2 (PO 4 ) 3 , Li 2 MnSiO 4 , Li 2 CoPO 4 F, and the like. Examples of chalcogen compounds include titanium disulfide, molybdenum disulfide, molybdenum dioxide, and the like. Atoms or polyanions in these materials may be partially substituted with atoms or anion species of other elements. Among these, the above-mentioned positive electrode active material is preferably the above-mentioned lithium-transition metal composite oxide from the viewpoint of high energy density, and a nickel-cobalt-manganese-containing lithium-transition metal composite containing nickel, cobalt, and manganese as constituent elements in addition to lithium. Oxides are more preferred.
上記正極活物質として挙げられた材料は表面が他の材料で被覆されていてもよい。正極活物質層においては、これら材料の１種を単独で用いてもよく、２種以上を混合して用いてもよい。 The surface of the material listed as the positive electrode active material may be coated with another material. In the positive electrode active material layer, one type of these materials may be used alone, or two or more types may be used in combination.
正極活物質層中の正極活物質の含有量は特に限定されないが、その下限としては、５０質量％が好ましく、８０質量％がより好ましく、９０質量％がさらに好ましい。一方、この含有量の上限としては、９９質量％が好ましく、９８質量％がより好ましい。 The content of the positive electrode active material in the positive electrode active material layer is not particularly limited, but its lower limit is preferably 50% by mass, more preferably 80% by mass, and even more preferably 90% by mass. On the other hand, the upper limit of this content is preferably 99% by mass, more preferably 98% by mass.
（その他の任意成分）
正極合剤は、必要に応じて導電剤、バインダー、増粘剤、フィラー等の任意成分を含む。導電剤、バインダー、増粘剤、フィラー等の任意成分は、上記負極で例示した材料から選択できる。
(Other optional ingredients)
The positive electrode mixture contains optional components such as a conductive agent, a binder, a thickener, and a filler, as necessary. Optional components such as a conductive agent, a binder, a thickener, and a filler can be selected from the materials exemplified for the negative electrode.
（中間層）
上記中間層は、正極基材の表面の被覆層であり、炭素粒子等の導電性粒子を含むことで正極基材と正極活物質層との接触抵抗を低減する。上記負極と同様に、中間層の構成は特に限定されず、例えば樹脂バインダー及び導電性粒子を含有する組成物により形成できる。
［非水電解質］
上記非水電解質としては、一般的な非水電解質二次電池（蓄電素子）に通常用いられる公知の非水電解質が使用できる。上記非水電解質は、非水溶媒と、この非水溶媒に溶解されている電解質塩を含む。なお、上記非水電解質は、固体電解質等であってもよい。
(middle class)
The intermediate layer is a coating layer on the surface of the positive electrode base material, and contains conductive particles such as carbon particles to reduce contact resistance between the positive electrode base material and the positive electrode active material layer. Similar to the above negative electrode, the structure of the intermediate layer is not particularly limited, and can be formed, for example, from a composition containing a resin binder and conductive particles.
[Nonaqueous electrolyte]
As the non-aqueous electrolyte, a known non-aqueous electrolyte that is commonly used in general non-aqueous electrolyte secondary batteries (power storage elements) can be used. The nonaqueous electrolyte includes a nonaqueous solvent and an electrolyte salt dissolved in the nonaqueous solvent. Note that the non-aqueous electrolyte may be a solid electrolyte or the like.
上記非水溶媒としては、一般的な蓄電素子用非水電解質の非水溶媒として通常用いられる公知の非水溶媒を用いることができる。上記非水溶媒としては、環状カーボネート、鎖状カーボネート、エステル、エーテル、アミド、スルホン、ラクトン、ニトリル等を挙げることができる。これらの中でも、環状カーボネート又は鎖状カーボネートを少なくとも用いることが好ましく、環状カーボネートと鎖状カーボネートとを併用することがより好ましい。環状カーボネートと鎖状カーボネートとを併用する場合、環状カーボネートと鎖状カーボネートとの体積比（環状カーボネート：鎖状カーボネート）としては、特に限定されないが、例えば５：９５から５０：５０とすることが好ましい。 As the non-aqueous solvent, a known non-aqueous solvent that is commonly used as a non-aqueous solvent for a general non-aqueous electrolyte for a power storage device can be used. Examples of the nonaqueous solvent include cyclic carbonates, chain carbonates, esters, ethers, amides, sulfones, lactones, and nitriles. Among these, it is preferable to use at least a cyclic carbonate or a chain carbonate, and it is more preferable to use a cyclic carbonate and a chain carbonate in combination. When using a cyclic carbonate and a chain carbonate together, the volume ratio of the cyclic carbonate to the chain carbonate (cyclic carbonate: chain carbonate) is not particularly limited, but may be, for example, from 5:95 to 50:50. preferable.
上記環状カーボネートとしては、エチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）、ブチレンカーボネート（ＢＣ）、ビニレンカーボネート（ＶＣ）、ビニルエチレンカーボネート（ＶＥＣ）、クロロエチレンカーボネート、フルオロエチレンカーボネート（ＦＥＣ）、ジフルオロエチレンカーボネート（ＤＦＥＣ）、スチレンカーボネート、カテコールカーボネート、１－フェニルビニレンカーボネート、１，２－ジフェニルビニレンカーボネート等を挙げることができ、これらの中でもＥＣが好ましい。 Examples of the cyclic carbonates include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), vinylethylene carbonate (VEC), chloroethylene carbonate, fluoroethylene carbonate (FEC), and difluoroethylene. carbonate (DFEC), styrene carbonate, catechol carbonate, 1-phenylvinylene carbonate, 1,2-diphenylvinylene carbonate, etc. Among these, EC is preferred.
上記鎖状カーボネートとしては、ジエチルカーボネート（ＤＥＣ）、ジメチルカーボネート（ＤＭＣ）、エチルメチルカーボネート（ＥＭＣ）、ジフェニルカーボネート等を挙げることができ、これらの中でもＥＭＣが好ましい。 Examples of the chain carbonate include diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), and diphenyl carbonate, and among these, EMC is preferred.
上記電解質塩としては、一般的な蓄電素子用非水電解質の電解質塩として通常用いられる公知の電解質塩を用いることができる。上記電解質塩としては、リチウム塩、ナトリウム塩、カリウム塩、マグネシウム塩、オニウム塩等を挙げることができるが、リチウム塩が好ましい。 As the electrolyte salt, a known electrolyte salt that is commonly used as an electrolyte salt of a general non-aqueous electrolyte for a power storage device can be used. Examples of the electrolyte salts include lithium salts, sodium salts, potassium salts, magnesium salts, onium salts, and the like, with lithium salts being preferred.
上記リチウム塩としては、ＬｉＰＦ６、ＬｉＰＯ２Ｆ２、ＬｉＢＦ４、ＬｉＣｌＯ４、ＬｉＮ（ＳＯ２Ｆ）２等の無機リチウム塩、ＬｉＳＯ３ＣＦ３、ＬｉＮ（ＳＯ２ＣＦ３）２、ＬｉＮ（ＳＯ２Ｃ２Ｆ５）２、ＬｉＮ（ＳＯ２ＣＦ３）（ＳＯ２Ｃ４Ｆ９）、ＬｉＣ（ＳＯ２ＣＦ３）３、ＬｉＣ（ＳＯ２Ｃ２Ｆ５）３等の水素がフッ素で置換された炭化水素基を有するリチウム塩などを挙げることができる。これらの中でも、無機リチウム塩が好ましく、ＬｉＰＦ６がより好ましい。 Examples of the lithium salt include inorganic lithium salts such as LiPF 6 , LiPO 2 F 2 , LiBF 4 , LiClO 4 , LiN(SO 2 F) 2 , LiSO 3 CF 3 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 Hydrogen in C 2 F 5 ) 2 , LiN(SO 2 CF 3 )(SO 2 C 4 F 9 ), LiC(SO 2 CF 3 ) 3 , LiC(SO 2 C 2 F 5 ) 3 is replaced with fluorine Examples include lithium salts having a hydrocarbon group. Among these, inorganic lithium salts are preferred, and LiPF 6 is more preferred.
上記非水電解質における上記電解質塩の濃度の下限としては、２０℃１気圧下において、０．１ｍｏｌ／ｄｍ３が好ましく、０．３ｍｏｌ／ｄｍ３がより好ましく、０．５ｍｏｌ／ｄｍ３がさらに好ましく、０．７ｍｏｌ／ｄｍ３が特に好ましい。一方、この上限としては、特に限定されないが、２．５ｍｏｌ／ｄｍ３が好ましく、２．０ｍｏｌ／ｄｍ３がより好ましく、１．５ｍｏｌ／ｄｍ３がさらに好ましい。 The lower limit of the concentration of the electrolyte salt in the non-aqueous electrolyte is preferably 0.1 mol/dm 3 , more preferably 0.3 mol/dm 3 , even more preferably 0.5 mol/dm 3 at 20°C and 1 atmosphere. , 0.7 mol/dm 3 is particularly preferred. On the other hand, this upper limit is not particularly limited, but is preferably 2.5 mol/dm 3 , more preferably 2.0 mol/dm 3 , and even more preferably 1.5 mol/dm 3 .
上記非水電解質には、その他の添加剤が添加されていてもよい。また、上記非水電解質として、常温溶融塩、イオン液体などを用いることもできる。 Other additives may be added to the non-aqueous electrolyte. Moreover, room temperature molten salts, ionic liquids, etc. can also be used as the non-aqueous electrolyte.
［セパレータ］
上記セパレータは、公知のセパレータの中から適宜選択できる。セパレータとして、例えば、基材層のみからなるセパレータ、基材層の一方の面又は双方の面に耐熱層が形成されたセパレータ等を使用することができる。セパレータの基材層の形態としては、例えば、織布、不織布、微多孔膜等が挙げられる。これらの形態の中でも、安全性の観点から微多孔膜が好ましい。セパレータの基材層の材料としては、例えばポリエチレン、ポリプロピレン等のポリオレフィン、ポリイミド、アラミド、これらの樹脂を複合した材料等が挙げられる。これらの中でもポリオレフィンが好ましい。上記基材層の主成分がポリオレフィンであることで、意図しない短絡等による過剰な発熱がおこった場合でも、電流のシャットダウン機能が働き、短絡電流の増大を抑制することができるため、高い安全性を備えることができる。
[Separator]
The separator can be appropriately selected from known separators. As the separator, for example, a separator consisting of only a base material layer, a separator in which a heat-resistant layer is formed on one surface or both surfaces of the base material layer, etc. can be used. Examples of the form of the base material layer of the separator include woven fabric, nonwoven fabric, and microporous membrane. Among these forms, microporous membranes are preferred from the viewpoint of safety. Examples of the material for the base layer of the separator include polyolefins such as polyethylene and polypropylene, polyimide, aramid, and composite materials of these resins. Among these, polyolefins are preferred. Since the main component of the base material layer is polyolefin, even if excessive heat generation occurs due to an unintentional short circuit, the current shutdown function works and suppresses the increase in short circuit current, resulting in high safety. can be provided.
上記セパレータの透気度の上限としては、２００［秒／１００ｃｍ３］であり、１５０［秒／１００ｃｍ３］が好ましく、１００［秒／１００ｃｍ３］がより好ましい。セパレータの透気度の上限が上記範囲であることで、急速充放電サイクル時の容量維持率の低下に対する抑制効果を高めることができる。一方、セパレータの透気度の下限としては、セパレータの強度維持の観点から４０［秒／１００ｃｍ３］が好ましく、６０［秒／１００ｃｍ３］がより好ましい。 The upper limit of the air permeability of the separator is 200 [seconds/100cm 3 ], preferably 150 [seconds/100cm 3 ], and more preferably 100 [seconds/100cm 3 ]. By setting the upper limit of the air permeability of the separator within the above range, it is possible to enhance the effect of suppressing a decrease in capacity retention rate during rapid charge/discharge cycles. On the other hand, the lower limit of the air permeability of the separator is preferably 40 [seconds/100cm 3 ] and more preferably 60 [seconds/100cm 3 ] from the viewpoint of maintaining the strength of the separator.
上記セパレータは、耐熱層を有することが好ましい。上記耐熱層は、無機粒子及びバインダーを含む。上記セパレータが無機粒子及びバインダーを含む耐熱層を有することで、意図せずに蓄電素子の温度が過剰に上昇した場合にもセパレータの破損を抑制して正極と負極との短絡をより確実に抑制するとともに、セパレータの形状維持を図ることができる。この耐熱層は、無機粒子及びバインダーを含む多孔質の層である。また、上記耐熱層は、無機粒子及びバインダー以外のその他の成分が含有されていてもよい。 It is preferable that the separator has a heat-resistant layer. The heat-resistant layer includes inorganic particles and a binder. Since the separator has a heat-resistant layer containing inorganic particles and a binder, even if the temperature of the electricity storage element unintentionally rises excessively, damage to the separator is suppressed and short circuits between the positive electrode and the negative electrode are more reliably suppressed. At the same time, the shape of the separator can be maintained. This heat-resistant layer is a porous layer containing inorganic particles and a binder. Further, the heat-resistant layer may contain components other than the inorganic particles and the binder.
耐熱層に含まれる無機粒子として無機化合物が挙げられる。無機化合物として、例えば、酸化鉄、酸化ケイ素、酸化アルミニウム、酸化チタン、チタン酸バリウム、酸化ジルコニウム、酸化カルシウム、酸化ストロンチウム、酸化バリウム、酸化マグネシウム、アルミノケイ酸塩等の酸化物；水酸化マグネシウム、水酸化カルシウム、水酸化アルミニウム等の水酸化物；窒化アルミニウム、窒化ケイ素等の窒化物；炭酸カルシウム等の炭酸塩；硫酸バリウム等の硫酸塩；フッ化カルシウム、フッ化バリウム等の難溶性のイオン結晶；シリコン、ダイヤモンド等の共有結合性結晶；タルク、モンモリロナイト、ベーマイト、ゼオライト、アパタイト、カオリン、ムライト、スピネル、オリビン、セリサイト、ベントナイト、マイカ等の鉱物資源由来物質又はこれらの人造物等が挙げられる。無機化合物として、これらの物質の単体又は複合体を単独で用いてもよく、２種以上を混合して用いてもよい。これらの無機化合物の中でも、二次電池の特性の観点から、酸化ケイ素、酸化アルミニウム、ベーマイト、又はアルミケイ酸塩が好ましい。耐熱層に含まれる無機粒子は、大気圧下で５００℃にて質量減少が５％以下であるものが好ましく、大気圧下で８００℃にて質量減少が５％以下であるものがさらに好ましい。 Examples of the inorganic particles contained in the heat-resistant layer include inorganic compounds. Examples of inorganic compounds include oxides such as iron oxide, silicon oxide, aluminum oxide, titanium oxide, barium titanate, zirconium oxide, calcium oxide, strontium oxide, barium oxide, magnesium oxide, aluminosilicate; magnesium hydroxide, water Hydroxides such as calcium oxide and aluminum hydroxide; Nitrides such as aluminum nitride and silicon nitride; Carbonates such as calcium carbonate; Sulfates such as barium sulfate; Hardly soluble ionic crystals such as calcium fluoride and barium fluoride Covalent crystals such as silicon and diamond; Substances derived from mineral resources such as talc, montmorillonite, boehmite, zeolite, apatite, kaolin, mullite, spinel, olivine, sericite, bentonite, and mica, or artificial products thereof. . As the inorganic compound, these substances may be used alone or in combination, or two or more types may be used in combination. Among these inorganic compounds, silicon oxide, aluminum oxide, boehmite, or aluminum silicate are preferred from the viewpoint of secondary battery characteristics. The inorganic particles contained in the heat-resistant layer preferably have a mass loss of 5% or less at 500° C. under atmospheric pressure, and more preferably have a mass loss of 5% or less at 800° C. under atmospheric pressure.
［非水電解質蓄電素子の具体的構成］
本実施形態の蓄電素子の形状については特に限定されるものではなく、例えば、円筒型電池、ラミネートフィルム型電池、角型電池、扁平型電池、コイン型電池、ボタン型電池等が挙げられる。
[Specific configuration of non-aqueous electrolyte storage element]
The shape of the power storage element of this embodiment is not particularly limited, and examples include a cylindrical battery, a laminate film battery, a square battery, a flat battery, a coin battery, a button battery, and the like.
図１に、本発明に係る非水電解質蓄電素子の一実施形態である矩形状の非水電解質蓄電素子１（非水電解質二次電池）の概略図を示す。なお、同図は、ケース内部を透視した図としている。セパレータを挟んで巻回された正極及び負極を有する電極体２が角型のケース３に収納される。正極は正極リード４１を介して正極端子４と電気的に接続されている。負極は負極リード５１を介して負極端子５と電気的に接続されている。また、ケース３には、非水電解質が注入されている。
FIG. 1 shows a schematic diagram of a rectangular nonaqueous electrolyte storage device 1 (nonaqueous electrolyte secondary battery), which is an embodiment of the nonaqueous electrolyte storage device according to the present invention. Note that this figure is a transparent view of the inside of the case. An
当該非水電解質蓄電素子の通常使用時の充電終止電圧における正極電位の範囲としては、４．２Ｖ（ｖｓ．Ｌｉ／Ｌｉ＋）以上が好ましく、４．２Ｖ（ｖｓ．Ｌｉ／Ｌｉ＋）以上４．５Ｖ（ｖｓ．Ｌｉ／Ｌｉ＋）以下がより好ましい。当該非水電解質蓄電素子は、上記構成を備えることで、高電圧で作動する場合においても、急速充放電サイクル時の容量維持率の低下が抑制される。従って、当該非水電解質蓄電素子は、通常使用時の充電終止電圧における正極電位が上記範囲である場合に、急速充放電サイクル性能の改善という効果をより十分に発揮することができる。 The range of the positive electrode potential at the end-of-charge voltage during normal use of the nonaqueous electrolyte storage element is preferably 4.2V (vs. Li/Li + ) or higher, and 4.2V (vs. Li/Li + ) or higher 4 .5V (vs. Li/Li + ) or less is more preferable. By having the above-mentioned configuration, the non-aqueous electrolyte storage element suppresses a decrease in capacity retention rate during rapid charge/discharge cycles even when operated at high voltage. Therefore, the non-aqueous electrolyte storage element can more fully exhibit the effect of improving rapid charge/discharge cycle performance when the positive electrode potential at the end-of-charge voltage during normal use is within the above range.
［非水電解質蓄電素子の製造方法］
本発明の一実施形態に係る非水電解質蓄電素子の製造方法は、当該正極を作製すること、負極を作製すること、非水電解質を調製すること、セパレータを介して正極及び負極を積層又は巻回することにより交互に重畳された電極体を形成すること、電極体を容器に収容すること、並びに上記容器に上記非水電解質を注入することを備える。上記正極は、正極基材に直接又は中間層を介して上記正極活物質層を積層することにより得ることができる。上記正極活物質層の積層は、正極基材に、正極合剤ペーストを塗工することにより行う。また、上記負極は、上記正極と同様、負極基材に直接又は中間層を介して上記負極活物質層を積層することにより得ることができる。上記負極活物質層の積層は、負極基材に、黒鉛及びアクリル樹脂を含む負極合剤ペーストを塗工することにより行う。上記正極合剤ペースト及び負極合剤ペーストは、分散媒を含んでいてもよい。この分散媒としては、例えば、水、水を主体とする混合溶媒等の水系溶媒；Ｎ－メチルピロリドン、トルエン等の有機系溶媒を用いることができる。
[Method for manufacturing non-aqueous electrolyte storage element]
A method for manufacturing a non-aqueous electrolyte energy storage device according to an embodiment of the present invention includes manufacturing the positive electrode, manufacturing the negative electrode, preparing the non-aqueous electrolyte, and laminating or winding the positive electrode and the negative electrode through a separator. The method includes forming alternately stacked electrode bodies by rotating the electrode bodies, housing the electrode bodies in a container, and injecting the non-aqueous electrolyte into the container. The above-mentioned positive electrode can be obtained by laminating the above-mentioned positive electrode active material layer on a positive electrode base material directly or via an intermediate layer. The above-mentioned positive electrode active material layer is laminated by applying a positive electrode mixture paste to the positive electrode base material. Further, the negative electrode can be obtained by laminating the negative electrode active material layer on the negative electrode base material directly or via an intermediate layer, similarly to the positive electrode. The negative electrode active material layer is laminated by applying a negative electrode mixture paste containing graphite and acrylic resin to the negative electrode base material. The positive electrode mixture paste and the negative electrode mixture paste may contain a dispersion medium. As the dispersion medium, for example, aqueous solvents such as water and a mixed solvent mainly composed of water; organic solvents such as N-methylpyrrolidone and toluene can be used.
上記負極、正極、非水電解質等をケースに収容する方法は、公知の方法により行うことができる。収容後、収容口を封止することにより非水電解質蓄電素子を得ることができる。上記製造方法によって得られる非水電解質蓄電素子を構成する各要素についての詳細は上述したとおりである。 The above-mentioned negative electrode, positive electrode, non-aqueous electrolyte, etc. can be housed in a case by a known method. After housing, a non-aqueous electrolyte storage element can be obtained by sealing the housing opening. The details of each element constituting the non-aqueous electrolyte storage device obtained by the above manufacturing method are as described above.
当該非水電解質蓄電素子によれば、負極活物質層が負極活物質としての黒鉛と、バインダーとしてのアクリル樹脂とを含み、上記正極及び上記負極間に介在するセパレータの透気度が２００［秒／１００ｃｍ３］以下であることで、非水電解質蓄電素子の急速充放電サイクル時の容量維持率の低下を抑制できる。 According to the non-aqueous electrolyte storage device, the negative electrode active material layer contains graphite as the negative electrode active material and acrylic resin as the binder, and the separator interposed between the positive electrode and the negative electrode has an air permeability of 200 seconds. /100cm 3 ] or less, it is possible to suppress a decrease in the capacity retention rate of the nonaqueous electrolyte storage element during rapid charge/discharge cycles.
［その他の実施形態］
本発明の非水電解質蓄電素子は、上記実施形態に限定されるものではない。
[Other embodiments]
The non-aqueous electrolyte storage device of the present invention is not limited to the above embodiments.
また、上記実施形態においては、非水電解質蓄電素子が非水電解質二次電池である形態を中心に説明したが、その他の非水電解質蓄電素子であってもよい。その他の非水電解質蓄電素子としては、キャパシタ（電気二重層キャパシタ、リチウムイオンキャパシタ）等が挙げられる。非水電解質二次電池としては、リチウムイオン非水電解質二次電池が挙げられる。 Further, in the above embodiments, the non-aqueous electrolyte storage element is mainly a non-aqueous electrolyte secondary battery, but other non-aqueous electrolyte storage elements may be used. Other nonaqueous electrolyte storage devices include capacitors (electric double layer capacitors, lithium ion capacitors), and the like. Examples of nonaqueous electrolyte secondary batteries include lithium ion nonaqueous electrolyte secondary batteries.
また、上記実施形態においては巻回型の電極体を用いていたが、正極、負極及びセパレータを備える複数のシート体を重ねた積層体から形成される積層型電極体を備えてもよい。 Further, although a wound type electrode body is used in the above embodiment, a laminated type electrode body formed from a laminated body in which a plurality of sheet bodies each including a positive electrode, a negative electrode, and a separator are stacked may be provided.
本発明は、複数の上記非水電解質蓄電素子を備える蓄電装置としても実現することができる。この場合、蓄電装置に含まれる少なくとも一つの非水電解質蓄電素子に対して、本発明の技術が適用されていればよい。また、単数個又は複数個の本発明の非水電解質蓄電素子（セル）を用いることにより組電池を構成することができ、さらにこの組電池を用いて蓄電装置を構成することができる。上記蓄電装置は、電気自動車（ＥＶ）、ハイブリッド自動車（ＨＥＶ）、プラグインハイブリッド自動車（ＰＨＥＶ）等の自動車用電源として用いることができる。さらに、上記蓄電装置は、エンジン始動用電源装置、補機用電源装置、無停電電源装置（ＵＰＳ）等の種々の電源装置に用いることができる。 The present invention can also be realized as a power storage device including a plurality of the above non-aqueous electrolyte power storage elements. In this case, the technology of the present invention may be applied to at least one non-aqueous electrolyte power storage element included in the power storage device. Moreover, a battery assembly can be constructed by using one or more non-aqueous electrolyte power storage elements (cells) of the present invention, and furthermore, a power storage device can be constructed using this battery assembly. The power storage device described above can be used as a power source for automobiles such as electric vehicles (EVs), hybrid vehicles (HEVs), and plug-in hybrid vehicles (PHEVs). Further, the power storage device can be used in various power supply devices such as an engine starting power supply device, an auxiliary machine power supply device, and an uninterruptible power supply (UPS).
図２に、電気的に接続された二以上の非水電解質蓄電素子１が集合した蓄電ユニット２０をさらに集合した蓄電装置３０の一例を示す。蓄電装置３０は、二以上の非水電解質蓄電素子１を電気的に接続するバスバ（図示せず）、二以上の蓄電ユニット２０を電気的に接続するバスバ（図示せず）を備えていてもよい。蓄電ユニット２０又は蓄電装置３０は、一以上の蓄電素子の状態を監視する状態監視装置（図示せず）を備えていてもよい。
FIG. 2 shows an example of a
以下、実施例によって本発明をさらに具体的に説明するが、本発明は以下の実施例に限定されるものではない。 EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples.
［実施例１及び比較例１から比較例３］
（負極）
負極活物質層のバインダーとして、アクリル樹脂又はスチレンブタジエン共重合体を用いた。負極活物質としての黒鉛と、表１に記載のバインダーと、増粘剤としてのＣＭＣを含有し、水を分散媒とする負極合剤ペーストを調製した。負極活物質、バインダー、増粘剤の混合比率は、質量比で９８：１：１とした。負極合剤ペーストを厚さ１０μｍの銅箔基材の両面に１３ｍｇ／ｃｍ２の塗布質量（目付量、固形分換算）で塗布し、乾燥して、負極活物質層を形成し、充填密度が１．５ｇ／ｃｍ３となるようにプレスをおこない実施例及び比較例の負極を得た。
（非水電解質）
エチレンカーボネート（ＥＣ）及びエチルメチルカーボネート（ＥＭＣ）を体積比３０：７０で混合した非水溶媒に、ＬｉＰＦ６を１．０ｍｏｌ／ｄｍ３溶解させた非水電解質を調製した。
（正極）
α―ＮａＦｅＯ２型結晶構造を有するＮＣＭ（ＬｉＮｉ０．５Ｃｏ０．２Ｍｎ０．３Ｏ２）を正極活物質として含有する正極を作製した。正極は、上記正極活物質と、バインダーとしてのポリフッ化ビニリデン（ＰＶＤＦ）と、導電剤としてのアセチレンブラックとを含有し、Ｎ－メチル－２－ピロリドン（ＮＭＰ）を分散媒とする正極合剤ペーストを調製した。正極活物質、バインダー、導電剤の混合比率は、質量比で、９３：４：３とした。正極合剤ペーストを厚さ１５μｍのアルミニウム箔からなる正極基材の両面に２５ｍｇ／ｃｍ２の塗布質量（目付量、固形分換算）で塗工し、乾燥し、プレスして、正極活物質層を形成した。
[Example 1 and Comparative Examples 1 to 3]
(Negative electrode)
Acrylic resin or styrene-butadiene copolymer was used as a binder for the negative electrode active material layer. A negative electrode mixture paste containing graphite as a negative electrode active material, the binder listed in Table 1, and CMC as a thickener, and using water as a dispersion medium was prepared. The mixing ratio of the negative electrode active material, binder, and thickener was 98:1:1 by mass. The negative electrode mixture paste was applied to both sides of a copper foil base material with a thickness of 10 μm at a coating weight of 13 mg/cm 2 (fabric weight, solid content equivalent), dried to form a negative electrode active material layer, and the packing density was Negative electrodes of Examples and Comparative Examples were obtained by pressing so that the density was 1.5 g/cm 3 .
(Nonaqueous electrolyte)
A non-aqueous electrolyte was prepared by dissolving 1.0 mol/dm 3 of LiPF 6 in a non-aqueous solvent in which ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed at a volume ratio of 30:70.
(positive electrode)
A positive electrode containing NCM (LiNi 0.5 Co 0.2 Mn 0.3 O 2 ) having an α-NaFeO 2 type crystal structure as a positive electrode active material was produced. The positive electrode is a positive electrode mixture paste containing the above positive electrode active material, polyvinylidene fluoride (PVDF) as a binder, and acetylene black as a conductive agent, and using N-methyl-2-pyrrolidone (NMP) as a dispersion medium. was prepared. The mixing ratio of the positive electrode active material, binder, and conductive agent was 93:4:3 in terms of mass ratio. A positive electrode mixture paste is applied to both sides of a positive electrode base material made of aluminum foil with a thickness of 15 μm at a coating weight of 25 mg/cm 2 (fabric weight, solid content equivalent), dried, and pressed to form a positive electrode active material layer. was formed.
（非水電解質蓄電素子の作製）
次に、セパレータとして、ポリエチレンからなる微多孔膜状の基材層及び上記基材層の片面に形成された無機層からなり、表１に記載の透気度を有するセパレータを用いた。上記セパレータを介して、上記正極と上記負極とを積層し、電極体を作製した。この電極体をアルミニウム製の角形のケースに収納し、正極端子及び負極端子を取り付けた。このケース内部に上記非水電解質を注入した後、封口し、定格容量０．９Ａｈの非水電解質二次電池を作製することにより、実施例及び比較例の非水電解質蓄電素子を得た。
(Production of non-aqueous electrolyte storage element)
Next, as a separator, a separator consisting of a microporous film-like base material layer made of polyethylene and an inorganic layer formed on one side of the base material layer, and having the air permeability shown in Table 1, was used. The positive electrode and the negative electrode were laminated with the separator interposed therebetween to produce an electrode body. This electrode body was housed in a rectangular case made of aluminum, and a positive electrode terminal and a negative electrode terminal were attached to it. After injecting the non-aqueous electrolyte into the case, the case was sealed and a non-aqueous electrolyte secondary battery with a rated capacity of 0.9 Ah was produced to obtain non-aqueous electrolyte storage elements of Examples and Comparative Examples.
［評価］
（初期充放電工程）
得られた各非水電解質蓄電素子について、充電終止電圧を４．２５Ｖとして、２５℃の温度環境下、０．１８Ａで総充電時間が７時間となるまで定電流定電圧充電をおこなった。次に、充電後に１０分間の休止を設けた。その後、放電終止電圧を２．７５Ｖとして、０．１８Ａの電流値で定電流放電をおこなった。次に、充電終止電圧を４．２５Ｖとして、２５℃の温度環境下、０．９Ａで総充電時間が３時間となるまで定電流定電圧充電をおこなった。１０分間の休止を設けた後、０．９Ａの電流値で定電流放電をおこなった。これらの放電容量が定格容量と同等であることを確認した。
[evaluation]
(Initial charging/discharging process)
Each of the obtained non-aqueous electrolyte storage elements was subjected to constant current and constant voltage charging at 0.18 A in a temperature environment of 25° C. with a charging end voltage of 4.25 V until a total charging time of 7 hours. Next, a 10-minute pause was provided after charging. Thereafter, constant current discharge was performed at a current value of 0.18A with a discharge end voltage of 2.75V. Next, with a charging end voltage of 4.25 V, constant current and constant voltage charging was performed at 0.9 A in a temperature environment of 25° C. until the total charging time reached 3 hours. After a 10-minute break, constant current discharge was performed at a current value of 0.9A. It was confirmed that these discharge capacities were equivalent to the rated capacities.
（急速充放電サイクル試験）
上記初期充放電工程を経て完成した実施例１及び比較例１から比較例３の非水電解質蓄電素子について、以下の条件にて充放電サイクル試験を行った。２５℃の恒温槽内で以下のサイクル試験を行った。それぞれＳＯＣ（Ｓｔａｔｅ ｏｆ Ｃｈａｒｇｅ）１００％となる電圧まで１．８Ａで総充電時間が３時間になるまで定電流定電圧充電をおこなった。次に、充電後に１０分間の休止を設けた。その後、ＳＯＣ０％となる電圧まで放電電流１．８Ａで定電流放電をおこない、１０分間の休止を設けた。さらに、ＳＯＣ０％となる電圧まで放電電流０．０４５Ａで定電流放電をおこない、１０分間の休止を実施した。これら充電及び放電の工程を１サイクルとして、このサイクルを１０サイクル繰り返した。
(Rapid charge/discharge cycle test)
A charge/discharge cycle test was conducted on the nonaqueous electrolyte storage elements of Example 1 and Comparative Examples 1 to 3 completed through the above initial charge/discharge process under the following conditions. The following cycle test was conducted in a constant temperature bath at 25°C. Constant current and constant voltage charging was performed at 1.8 A until the total charging time was 3 hours until the voltage reached 100% SOC (State of Charge). Next, a 10-minute pause was provided after charging. Thereafter, constant current discharge was performed at a discharge current of 1.8 A until the voltage reached SOC 0%, and a 10-minute pause was provided. Further, constant current discharge was performed at a discharge current of 0.045 A until the voltage reached SOC 0%, and a rest period of 10 minutes was performed. These charging and discharging steps were considered as one cycle, and this cycle was repeated 10 times.
（急速充放電サイクル時の容量維持率）
実施例１及び比較例１から比較例３の非水電解質蓄電素子について、急速充放電サイクル試験時の１サイクル目の１．８Ａ放電時の放電容量に対する１０サイクル目の１．８Ａ放電時の放電容量を容量維持率として求めた。結果を下記表１に示す。
(Capacity retention rate during rapid charge/discharge cycles)
Regarding the nonaqueous electrolyte storage elements of Example 1 and Comparative Examples 1 to 3, the discharge capacity at 1.8 A discharge in the 10th cycle versus the discharge capacity at 1.8 A discharge in the 1st cycle during the rapid charge/discharge cycle test The capacity was determined as a capacity retention rate. The results are shown in Table 1 below.
表１に示されるように、負極活物質層がアクリル樹脂を含み、セパレータの透気度が２００［秒／１００ｃｍ３］以下である実施例１は、急速充放電サイクル時の容量維持率が良好であった。また、透気度が２００［秒／１００ｃｍ３］以下であるセパレータを備える実施例１及び比較例１においては、負極活物質層がスチレンブタジエン共重合体を含む比較例１の方がアクリル樹脂を含む実施例１よりも容量維持率が小さかった。一方、透気度が２００［秒／１００ｃｍ３］を超えるセパレータを備える比較例２及び比較例３においては、負極活物質層がスチレンブタジエン共重合体を含む比較例３の方がアクリル樹脂を含む比較例２よりも容量維持率が大きかった。これらのことから、アクリル樹脂からなるバインダーを含む負極活物質層を有する負極と透気度が２００［秒／１００ｃｍ３］以下であるセパレータとを組み合わせて用いることで、急速充放電サイクル時の容量維持率の低下に対する改善効果が非常に高いことがわかる。 As shown in Table 1, Example 1, in which the negative electrode active material layer contains an acrylic resin and the separator has an air permeability of 200 seconds/100 cm 3 or less, has a good capacity retention rate during rapid charge/discharge cycles. Met. In addition, in Example 1 and Comparative Example 1, which include a separator with an air permeability of 200 seconds/100 cm 3 or less, Comparative Example 1, in which the negative electrode active material layer contains a styrene-butadiene copolymer, has a separator with an acrylic resin. The capacity retention rate was lower than that of Example 1, which included the following. On the other hand, in Comparative Examples 2 and 3 that include separators with an air permeability exceeding 200 seconds/100 cm 3 , Comparative Example 3 in which the negative electrode active material layer contains a styrene-butadiene copolymer contains more acrylic resin. The capacity retention rate was higher than that of Comparative Example 2. For these reasons, by using a negative electrode having a negative electrode active material layer containing a binder made of acrylic resin in combination with a separator having an air permeability of 200 seconds/100 cm 3 or less, the capacity during rapid charge/discharge cycles can be increased. It can be seen that the improvement effect on the decline in retention rate is extremely high.
以上のように、当該非水電解質蓄電素子は、急速充放電サイクル時の容量維持率の低下を抑制できることが示された。 As described above, it has been shown that the non-aqueous electrolyte storage element can suppress a decrease in capacity retention rate during rapid charge/discharge cycles.
本発明は、パーソナルコンピュータ、通信端末等の電子機器、ＥＶ、ＨＥＶ、ＰＨＥＶ等の自動車などの急速充電が要求される電源として使用される非水電解質二次電池をはじめとした非水電解質蓄電素子として好適に用いられる。
また、本発明の好ましい適用対象として、大型のリチウムイオン二次電池が挙げられる。例えば、電池容量が５．０Ａｈ以上（例えば５．０Ａｈ以上１００Ａｈ以下）の大容量タイプであって、かつ、３Ｃ以上（例えば３Ｃから５０Ｃ）のハイレート放電を含む充放電サイクルで使用されることが想定される大型のリチウムイオン二次電池が例示される。本発明に係る非水電解質蓄電素子は、急速充放電サイクル時の容量維持率に優れるため、上述した大型のリチウムイオン二次電池に好適に適用され得る。
The present invention relates to non-aqueous electrolyte storage elements such as non-aqueous electrolyte secondary batteries used as power sources for electronic devices such as personal computers and communication terminals, and automobiles such as EVs, HEVs, and PHEVs that require rapid charging. It is suitably used as
Moreover, a large-sized lithium ion secondary battery is mentioned as a preferable application target of the present invention. For example, it is a large capacity type with a battery capacity of 5.0 Ah or more (for example, 5.0 Ah or more and 100 Ah or less), and can be used in charge/discharge cycles that include high-rate discharge of 3 C or more (for example, from 3 C to 50 C). A hypothetical large-sized lithium ion secondary battery is exemplified. The non-aqueous electrolyte storage device according to the present invention has an excellent capacity retention rate during rapid charge/discharge cycles, and therefore can be suitably applied to the above-mentioned large lithium ion secondary battery.
１ 蓄電素子
２ 電極体
３ ケース
４ 正極端子
４１ 正極リード
５ 負極端子
５１ 負極リード
２０ 蓄電ユニット
３０ 蓄電装置
1
Claims (4)
負極と、
上記正極及び上記負極間に介在するセパレータと
を備えており、
上記負極が黒鉛及びアクリル樹脂を含む負極活物質層を有し、
上記セパレータの透気度が２００［秒／１００ｃｍ３］以下である非水電解質蓄電素子（但し、正極集電体及び前記正極集電体上に形成された正極活物質層を備える正極と、負極集電体及び前記負極集電体上に形成された負極活物質層を備える負極と、前記正極及び負極の間に配置されるセパレータと、を備える電極体であって、前記正極活物質層及び前記負極活物質層の表面粗さがともに０．２～５μｍであり、前記セパレータの表面粗さが０．０６μｍ以上である電極体を備え、前記負極活物質層がフッ素変性（メタ）アクリル系バインダーを含む場合を除く。）。 a positive electrode;
a negative electrode;
and a separator interposed between the positive electrode and the negative electrode,
The negative electrode has a negative electrode active material layer containing graphite and acrylic resin,
A non-aqueous electrolyte storage element in which the separator has an air permeability of 200 seconds/100 cm 3 or less (provided that a positive electrode comprising a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector, and a negative electrode An electrode body comprising: a negative electrode including a current collector and a negative electrode active material layer formed on the negative electrode current collector; and a separator disposed between the positive electrode and the negative electrode, the electrode body comprising: The negative electrode active material layer includes an electrode body in which the surface roughness of the negative electrode active material layer is 0.2 to 5 μm, and the separator has a surface roughness of 0.06 μm or more, and the negative electrode active material layer is made of fluorine-modified (meth)acrylic. (Excluding cases including binders).
上記基材層の主成分がポリオレフィンである請求項１又は請求項２に記載の非水電解質蓄電素子。 The separator has a microporous membrane-like base material layer,
3. The non-aqueous electrolyte storage device according to claim 1, wherein the main component of the base layer is polyolefin.
上記耐熱層が無機粒子及びバインダーを含む請求項１、請求項２又は請求項３に記載の非水電解質蓄電素子。
The separator has a heat-resistant layer,
4. The non-aqueous electrolyte storage device according to claim 1, wherein the heat-resistant layer contains inorganic particles and a binder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020021702A JP7409132B2 (en) | 2020-02-12 | 2020-02-12 | Nonaqueous electrolyte storage element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020021702A JP7409132B2 (en) | 2020-02-12 | 2020-02-12 | Nonaqueous electrolyte storage element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2021128843A JP2021128843A (en) | 2021-09-02 |
| JP7409132B2 true JP7409132B2 (en) | 2024-01-09 |
Family
ID=77488863
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2020021702A Active JP7409132B2 (en) | 2020-02-12 | 2020-02-12 | Nonaqueous electrolyte storage element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP7409132B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023074559A1 (en) * | 2021-10-25 | 2023-05-04 | 株式会社Ｇｓユアサ | Power storage element |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016048652A (en) | 2014-08-28 | 2016-04-07 | トヨタ自動車株式会社 | Nonaqueous electrolyte secondary battery |
| JP2017098204A (en) | 2015-11-27 | 2017-06-01 | 日本ゼオン株式会社 | Nonaqueous secondary battery |
| JP2018104713A (en) | 2016-02-09 | 2018-07-05 | 宇部興産株式会社 | Polyolefin microporous membrane |
| JP2019021805A (en) | 2017-07-19 | 2019-02-07 | Jsr株式会社 | Electrode body and electric storage device |
-
2020
- 2020-02-12 JP JP2020021702A patent/JP7409132B2/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016048652A (en) | 2014-08-28 | 2016-04-07 | トヨタ自動車株式会社 | Nonaqueous electrolyte secondary battery |
| JP2017098204A (en) | 2015-11-27 | 2017-06-01 | 日本ゼオン株式会社 | Nonaqueous secondary battery |
| JP2018104713A (en) | 2016-02-09 | 2018-07-05 | 宇部興産株式会社 | Polyolefin microporous membrane |
| JP2019021805A (en) | 2017-07-19 | 2019-02-07 | Jsr株式会社 | Electrode body and electric storage device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2021128843A (en) | 2021-09-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2021132208A1 (en) | Electricity storage element | |
| JP7472579B2 (en) | Positive electrode for energy storage element and energy storage element | |
| JP2018049821A (en) | Nonaqueous electrolyte for power storage element, nonaqueous electrolyte power storage element, and method for manufacturing nonaqueous electrolyte power storage element | |
| JP7409132B2 (en) | Nonaqueous electrolyte storage element | |
| US20230006188A1 (en) | Energy storage device | |
| JP2018078029A (en) | Negative electrode and nonaqueous electrolyte power storage device | |
| JP2021190184A (en) | Non-aqueous electrolyte power storage element | |
| JP7451995B2 (en) | Energy storage element | |
| WO2023224071A1 (en) | Nonaqueous electrolyte power storage element | |
| WO2022009734A1 (en) | Nonaqueous electrolyte power storage element | |
| JP7451994B2 (en) | Energy storage element | |
| WO2022097612A1 (en) | Positive electrode for non-aqueous electrolyte power storage element, non-aqueous electrolyte power storage element, and power storage device | |
| WO2023171796A1 (en) | Negative electrode, power storage element, and power storage device | |
| WO2021141074A1 (en) | Non-aqueous electrolyte power storage element and method for manufacturing same | |
| JP7371571B2 (en) | Non-aqueous electrolyte storage device and method for manufacturing the same | |
| WO2023224070A1 (en) | Non-aqueous electrolyte power storage element | |
| WO2022249667A1 (en) | Nonaqueous electrolyte power storage element and power storage device | |
| WO2023190422A1 (en) | Positive electrode for non-aqueous electrolyte power storage element, and non-aqueous electrolyte power storage element comprising same | |
| JP7451996B2 (en) | Energy storage element | |
| WO2023248769A1 (en) | Active material particles, electrode, power storage element and power storage device | |
| WO2023243520A1 (en) | Non-aqueous electrolyte and non-aqueous electrolyte electric power storage element | |
| WO2021049178A1 (en) | Non-aqueous electrolyte power storage element and power storage device | |
| WO2024062862A1 (en) | Electrode, electric power storage element and electric power storage device | |
| WO2022163125A1 (en) | Nonaqueous electrolyte power storage element, power storage device, and method for producing nonaqueous electrolyte power storage element | |
| WO2022239520A1 (en) | Power storage element, manufacturing method therefor, and power storage device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20221121 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20230628 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20230704 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20230824 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20231121 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20231204 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 7409132 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |