JP2017130274A - Negative electrode material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery - Google Patents
Negative electrode material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery Download PDFInfo
- Publication number
- JP2017130274A JP2017130274A JP2016007154A JP2016007154A JP2017130274A JP 2017130274 A JP2017130274 A JP 2017130274A JP 2016007154 A JP2016007154 A JP 2016007154A JP 2016007154 A JP2016007154 A JP 2016007154A JP 2017130274 A JP2017130274 A JP 2017130274A
- Authority
- JP
- Japan
- Prior art keywords
- lithium secondary
- active material
- secondary battery
- mass
- negative electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 151
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 151
- 239000007773 negative electrode material Substances 0.000 title claims abstract description 59
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 43
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 186
- 239000011149 active material Substances 0.000 claims abstract description 177
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 156
- 239000010439 graphite Substances 0.000 claims abstract description 156
- 238000000034 method Methods 0.000 claims abstract description 112
- 239000002131 composite material Substances 0.000 claims abstract description 110
- 229910021384 soft carbon Inorganic materials 0.000 claims abstract description 55
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 33
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 33
- 229910021385 hard carbon Inorganic materials 0.000 claims abstract description 31
- 239000000203 mixture Substances 0.000 claims description 111
- 238000010438 heat treatment Methods 0.000 claims description 62
- 230000008569 process Effects 0.000 claims description 53
- 239000002245 particle Substances 0.000 claims description 49
- 238000002156 mixing Methods 0.000 claims description 42
- 238000005563 spheronization Methods 0.000 claims description 41
- 229920002125 Sokalan® Polymers 0.000 claims description 40
- 239000007833 carbon precursor Substances 0.000 claims description 22
- 239000002243 precursor Substances 0.000 claims description 15
- 238000006386 neutralization reaction Methods 0.000 claims description 8
- 229920000058 polyacrylate Polymers 0.000 claims description 7
- 239000012535 impurity Substances 0.000 claims description 6
- 238000004255 ion exchange chromatography Methods 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- 229910052787 antimony Inorganic materials 0.000 claims description 5
- 239000011300 coal pitch Substances 0.000 claims description 5
- 238000004438 BET method Methods 0.000 claims description 4
- 239000000571 coke Substances 0.000 claims description 4
- 239000000295 fuel oil Substances 0.000 claims description 4
- 229910052745 lead Inorganic materials 0.000 claims description 4
- 229910052749 magnesium Inorganic materials 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 238000005259 measurement Methods 0.000 claims description 4
- 239000011302 mesophase pitch Substances 0.000 claims description 4
- 239000011301 petroleum pitch Substances 0.000 claims description 4
- 229910052725 zinc Inorganic materials 0.000 claims description 4
- 229910052776 Thorium Inorganic materials 0.000 claims description 3
- 229910052770 Uranium Inorganic materials 0.000 claims description 3
- 229910052785 arsenic Inorganic materials 0.000 claims description 3
- 229910052788 barium Inorganic materials 0.000 claims description 3
- 229910052790 beryllium Inorganic materials 0.000 claims description 3
- 229910052793 cadmium Inorganic materials 0.000 claims description 3
- 229910052791 calcium Inorganic materials 0.000 claims description 3
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910052750 molybdenum Inorganic materials 0.000 claims description 3
- 229910052700 potassium Inorganic materials 0.000 claims description 3
- 229910052711 selenium Inorganic materials 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 3
- 229910052716 thallium Inorganic materials 0.000 claims description 3
- 229910052720 vanadium Inorganic materials 0.000 claims description 3
- 229910052726 zirconium Inorganic materials 0.000 claims description 3
- 238000009840 oxygen flask method Methods 0.000 claims description 2
- 239000002023 wood Substances 0.000 claims 1
- 229920000642 polymer Polymers 0.000 abstract description 14
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 abstract description 12
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 abstract description 12
- 239000007772 electrode material Substances 0.000 abstract description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 36
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 31
- 239000010410 layer Substances 0.000 description 28
- 239000002253 acid Substances 0.000 description 27
- 239000002002 slurry Substances 0.000 description 27
- 230000000694 effects Effects 0.000 description 26
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 24
- -1 graphite compound Chemical class 0.000 description 23
- 239000005011 phenolic resin Substances 0.000 description 23
- 229910052710 silicon Inorganic materials 0.000 description 23
- 239000000843 powder Substances 0.000 description 22
- 229910052751 metal Inorganic materials 0.000 description 21
- 239000002184 metal Substances 0.000 description 21
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 20
- 239000010703 silicon Substances 0.000 description 20
- 230000015572 biosynthetic process Effects 0.000 description 19
- 239000011294 coal tar pitch Substances 0.000 description 19
- 238000011156 evaluation Methods 0.000 description 18
- 239000002904 solvent Substances 0.000 description 18
- 239000011248 coating agent Substances 0.000 description 16
- 238000000576 coating method Methods 0.000 description 16
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
- 238000003786 synthesis reaction Methods 0.000 description 15
- 238000003756 stirring Methods 0.000 description 14
- 239000011230 binding agent Substances 0.000 description 12
- 239000003792 electrolyte Substances 0.000 description 12
- 229910021389 graphene Inorganic materials 0.000 description 12
- 229920005989 resin Polymers 0.000 description 12
- 239000011347 resin Substances 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 11
- 238000012545 processing Methods 0.000 description 11
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 10
- 238000003763 carbonization Methods 0.000 description 10
- 150000001875 compounds Chemical class 0.000 description 10
- 238000009826 distribution Methods 0.000 description 10
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 10
- 229910052757 nitrogen Inorganic materials 0.000 description 10
- 239000000243 solution Substances 0.000 description 10
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 9
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 9
- 238000010304 firing Methods 0.000 description 9
- 239000000463 material Substances 0.000 description 9
- 238000003825 pressing Methods 0.000 description 9
- 239000007787 solid Substances 0.000 description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 9
- 239000002033 PVDF binder Substances 0.000 description 8
- SMWDFEZZVXVKRB-UHFFFAOYSA-N Quinoline Chemical compound N1=CC=CC2=CC=CC=C21 SMWDFEZZVXVKRB-UHFFFAOYSA-N 0.000 description 8
- 239000002041 carbon nanotube Substances 0.000 description 8
- 229910021393 carbon nanotube Inorganic materials 0.000 description 8
- 239000008151 electrolyte solution Substances 0.000 description 8
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 8
- 238000010298 pulverizing process Methods 0.000 description 8
- 239000011521 glass Substances 0.000 description 7
- 239000000047 product Substances 0.000 description 7
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 6
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 239000011246 composite particle Substances 0.000 description 6
- 238000001035 drying Methods 0.000 description 6
- 229910021382 natural graphite Inorganic materials 0.000 description 6
- 239000011342 resin composition Substances 0.000 description 6
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 5
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 5
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 239000003575 carbonaceous material Substances 0.000 description 5
- 229910017604 nitric acid Inorganic materials 0.000 description 5
- 229920001568 phenolic resin Polymers 0.000 description 5
- 239000007774 positive electrode material Substances 0.000 description 5
- USHAGKDGDHPEEY-UHFFFAOYSA-L potassium persulfate Chemical compound [K+].[K+].[O-]S(=O)(=O)OOS([O-])(=O)=O USHAGKDGDHPEEY-UHFFFAOYSA-L 0.000 description 5
- 230000000630 rising effect Effects 0.000 description 5
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 4
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 4
- 230000001133 acceleration Effects 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 4
- 239000006229 carbon black Substances 0.000 description 4
- 238000010000 carbonizing Methods 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 229910001873 dinitrogen Inorganic materials 0.000 description 4
- 239000012153 distilled water Substances 0.000 description 4
- 238000007654 immersion Methods 0.000 description 4
- 229910044991 metal oxide Inorganic materials 0.000 description 4
- 150000004706 metal oxides Chemical class 0.000 description 4
- 230000003472 neutralizing effect Effects 0.000 description 4
- 239000003960 organic solvent Substances 0.000 description 4
- 230000000704 physical effect Effects 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 229920002554 vinyl polymer Polymers 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- 229920000049 Carbon (fiber) Polymers 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 3
- 229910013870 LiPF 6 Inorganic materials 0.000 description 3
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 230000000996 additive effect Effects 0.000 description 3
- BTANRVKWQNVYAZ-UHFFFAOYSA-N butan-2-ol Chemical compound CCC(C)O BTANRVKWQNVYAZ-UHFFFAOYSA-N 0.000 description 3
- 239000004917 carbon fiber Substances 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 229920001577 copolymer Polymers 0.000 description 3
- 239000011889 copper foil Substances 0.000 description 3
- 239000003822 epoxy resin Substances 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 229910052731 fluorine Inorganic materials 0.000 description 3
- 239000011737 fluorine Substances 0.000 description 3
- 239000008187 granular material Substances 0.000 description 3
- 239000003999 initiator Substances 0.000 description 3
- 230000002427 irreversible effect Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 239000011268 mixed slurry Substances 0.000 description 3
- 239000000178 monomer Substances 0.000 description 3
- 239000012299 nitrogen atmosphere Substances 0.000 description 3
- 239000004745 nonwoven fabric Substances 0.000 description 3
- 230000000737 periodic effect Effects 0.000 description 3
- 229920000647 polyepoxide Polymers 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 239000011541 reaction mixture Substances 0.000 description 3
- 230000027756 respiratory electron transport chain Effects 0.000 description 3
- 238000000527 sonication Methods 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000009210 therapy by ultrasound Methods 0.000 description 3
- 229910052718 tin Inorganic materials 0.000 description 3
- 239000002759 woven fabric Substances 0.000 description 3
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 2
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 description 2
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 2
- ZHNUHDYFZUAESO-UHFFFAOYSA-N Formamide Chemical compound NC=O ZHNUHDYFZUAESO-UHFFFAOYSA-N 0.000 description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- 229910013063 LiBF 4 Inorganic materials 0.000 description 2
- 229910013716 LiNi Inorganic materials 0.000 description 2
- XOBKSJJDNFUZPF-UHFFFAOYSA-N Methoxyethane Chemical compound CCOC XOBKSJJDNFUZPF-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 238000005411 Van der Waals force Methods 0.000 description 2
- 229920001893 acrylonitrile styrene Polymers 0.000 description 2
- 239000005456 alcohol based solvent Substances 0.000 description 2
- 150000001408 amides Chemical class 0.000 description 2
- RDOXTESZEPMUJZ-UHFFFAOYSA-N anisole Chemical compound COC1=CC=CC=C1 RDOXTESZEPMUJZ-UHFFFAOYSA-N 0.000 description 2
- 239000010405 anode material Substances 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 229920001940 conductive polymer Polymers 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000001186 cumulative effect Effects 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical compound O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 description 2
- 238000002296 dynamic light scattering Methods 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 239000011245 gel electrolyte Substances 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910052738 indium Inorganic materials 0.000 description 2
- 239000011229 interlayer Substances 0.000 description 2
- 238000005342 ion exchange Methods 0.000 description 2
- 150000002576 ketones Chemical class 0.000 description 2
- 238000007561 laser diffraction method Methods 0.000 description 2
- AMXOYNBUYSYVKV-UHFFFAOYSA-M lithium bromide Chemical compound [Li+].[Br-] AMXOYNBUYSYVKV-UHFFFAOYSA-M 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 239000012982 microporous membrane Substances 0.000 description 2
- 239000002048 multi walled nanotube Substances 0.000 description 2
- 150000002825 nitriles Chemical class 0.000 description 2
- LQNUZADURLCDLV-UHFFFAOYSA-N nitrobenzene Chemical compound [O-][N+](=O)C1=CC=CC=C1 LQNUZADURLCDLV-UHFFFAOYSA-N 0.000 description 2
- 229920003986 novolac Polymers 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- SCUZVMOVTVSBLE-UHFFFAOYSA-N prop-2-enenitrile;styrene Chemical compound C=CC#N.C=CC1=CC=CC=C1 SCUZVMOVTVSBLE-UHFFFAOYSA-N 0.000 description 2
- FVSKHRXBFJPNKK-UHFFFAOYSA-N propionitrile Chemical compound CCC#N FVSKHRXBFJPNKK-UHFFFAOYSA-N 0.000 description 2
- 239000007870 radical polymerization initiator Substances 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000002109 single walled nanotube Substances 0.000 description 2
- 239000007784 solid electrolyte Substances 0.000 description 2
- 229920003002 synthetic resin Polymers 0.000 description 2
- 239000000057 synthetic resin Substances 0.000 description 2
- 229920005992 thermoplastic resin Polymers 0.000 description 2
- 229920001187 thermosetting polymer Polymers 0.000 description 2
- PYOKUURKVVELLB-UHFFFAOYSA-N trimethyl orthoformate Chemical compound COC(OC)OC PYOKUURKVVELLB-UHFFFAOYSA-N 0.000 description 2
- LZDKZFUFMNSQCJ-UHFFFAOYSA-N 1,2-diethoxyethane Chemical compound CCOCCOCC LZDKZFUFMNSQCJ-UHFFFAOYSA-N 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- ZFPGARUNNKGOBB-UHFFFAOYSA-N 1-Ethyl-2-pyrrolidinone Chemical compound CCN1CCCC1=O ZFPGARUNNKGOBB-UHFFFAOYSA-N 0.000 description 1
- ZNQVEEAIQZEUHB-UHFFFAOYSA-N 2-ethoxyethanol Chemical compound CCOCCO ZNQVEEAIQZEUHB-UHFFFAOYSA-N 0.000 description 1
- JWUJQDFVADABEY-UHFFFAOYSA-N 2-methyltetrahydrofuran Chemical compound CC1CCCO1 JWUJQDFVADABEY-UHFFFAOYSA-N 0.000 description 1
- PPDFQRAASCRJAH-UHFFFAOYSA-N 2-methylthiolane 1,1-dioxide Chemical compound CC1CCCS1(=O)=O PPDFQRAASCRJAH-UHFFFAOYSA-N 0.000 description 1
- WSQZNZLOZXSBHA-UHFFFAOYSA-N 3,8-dioxabicyclo[8.2.2]tetradeca-1(12),10,13-triene-2,9-dione Chemical compound O=C1OCCCCOC(=O)C2=CC=C1C=C2 WSQZNZLOZXSBHA-UHFFFAOYSA-N 0.000 description 1
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 description 1
- SBUOHGKIOVRDKY-UHFFFAOYSA-N 4-methyl-1,3-dioxolane Chemical compound CC1COCO1 SBUOHGKIOVRDKY-UHFFFAOYSA-N 0.000 description 1
- 238000012935 Averaging Methods 0.000 description 1
- 239000004342 Benzoyl peroxide Substances 0.000 description 1
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 1
- 229930185605 Bisphenol Natural products 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 229910000846 In alloy Inorganic materials 0.000 description 1
- 229910010238 LiAlCl 4 Inorganic materials 0.000 description 1
- 229910015015 LiAsF 6 Inorganic materials 0.000 description 1
- 229910015044 LiB Inorganic materials 0.000 description 1
- 229910013684 LiClO 4 Inorganic materials 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- 229910010586 LiFeO 2 Inorganic materials 0.000 description 1
- 229910015643 LiMn 2 O 4 Inorganic materials 0.000 description 1
- 229910014689 LiMnO Inorganic materials 0.000 description 1
- 229910013534 LiN(HCF2CF2CH2OSO2)2 Inorganic materials 0.000 description 1
- 229910013528 LiN(SO2 CF3)2 Inorganic materials 0.000 description 1
- 229910013290 LiNiO 2 Inorganic materials 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 239000004640 Melamine resin Substances 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-M Methacrylate Chemical compound CC(=C)C([O-])=O CERQOIWHTDAKMF-UHFFFAOYSA-M 0.000 description 1
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 239000004696 Poly ether ether ketone Substances 0.000 description 1
- 229930182556 Polyacetal Natural products 0.000 description 1
- 239000004695 Polyether sulfone Substances 0.000 description 1
- 229920000265 Polyparaphenylene Polymers 0.000 description 1
- 239000004734 Polyphenylene sulfide Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 1
- 229910001245 Sb alloy Inorganic materials 0.000 description 1
- 229910000676 Si alloy Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229910001128 Sn alloy Inorganic materials 0.000 description 1
- 229910006404 SnO 2 Inorganic materials 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 description 1
- 239000006230 acetylene black Substances 0.000 description 1
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 1
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 1
- 239000004676 acrylonitrile butadiene styrene Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- PASDCCFISLVPSO-UHFFFAOYSA-N benzoyl chloride Chemical compound ClC(=O)C1=CC=CC=C1 PASDCCFISLVPSO-UHFFFAOYSA-N 0.000 description 1
- 125000003236 benzoyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C(*)=O 0.000 description 1
- 235000019400 benzoyl peroxide Nutrition 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 1
- 229910052795 boron group element Inorganic materials 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 229910052800 carbon group element Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 150000001786 chalcogen compounds Chemical class 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 229910000428 cobalt oxide Inorganic materials 0.000 description 1
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 description 1
- 238000009841 combustion method Methods 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 229920000547 conjugated polymer Polymers 0.000 description 1
- 125000004093 cyano group Chemical group *C#N 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 150000001993 dienes Chemical class 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 239000012776 electronic material Substances 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 239000003759 ester based solvent Substances 0.000 description 1
- 239000004210 ether based solvent Substances 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 239000007849 furan resin Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000007770 graphite material Substances 0.000 description 1
- 229910021469 graphitizable carbon Inorganic materials 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 238000010191 image analysis Methods 0.000 description 1
- 229910001410 inorganic ion Inorganic materials 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate Chemical compound [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 1
- 239000005453 ketone based solvent Substances 0.000 description 1
- 229910021450 lithium metal oxide Inorganic materials 0.000 description 1
- 229910003002 lithium salt Inorganic materials 0.000 description 1
- 159000000002 lithium salts Chemical class 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000006262 metallic foam Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- UZKWTJUDCOPSNM-UHFFFAOYSA-N methoxybenzene Substances CCCCOC=C UZKWTJUDCOPSNM-UHFFFAOYSA-N 0.000 description 1
- MBABOKRGFJTBAE-UHFFFAOYSA-N methyl methanesulfonate Chemical compound COS(C)(=O)=O MBABOKRGFJTBAE-UHFFFAOYSA-N 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
- 150000004767 nitrides Chemical class 0.000 description 1
- LYGJENNIWJXYER-UHFFFAOYSA-N nitromethane Chemical compound C[N+]([O-])=O LYGJENNIWJXYER-UHFFFAOYSA-N 0.000 description 1
- 229910021470 non-graphitizable carbon Inorganic materials 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 239000010680 novolac-type phenolic resin Substances 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 150000002978 peroxides Chemical class 0.000 description 1
- JRKICGRDRMAZLK-UHFFFAOYSA-L peroxydisulfate Chemical compound [O-]S(=O)(=O)OOS([O-])(=O)=O JRKICGRDRMAZLK-UHFFFAOYSA-L 0.000 description 1
- 229910052696 pnictogen Inorganic materials 0.000 description 1
- 229920002492 poly(sulfone) Polymers 0.000 description 1
- 229920001197 polyacetylene Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 229920006393 polyether sulfone Polymers 0.000 description 1
- 229920002530 polyetherether ketone Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 239000005518 polymer electrolyte Substances 0.000 description 1
- 229920000193 polymethacrylate Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920006324 polyoxymethylene Polymers 0.000 description 1
- 229920001955 polyphenylene ether Polymers 0.000 description 1
- 229920000069 polyphenylene sulfide Polymers 0.000 description 1
- 229920000128 polypyrrole Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000011134 resol-type phenolic resin Substances 0.000 description 1
- 229920003987 resole Polymers 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000000790 scattering method Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 229920002379 silicone rubber Polymers 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- RCYJPSGNXVLIBO-UHFFFAOYSA-N sulfanylidenetitanium Chemical compound [S].[Ti] RCYJPSGNXVLIBO-UHFFFAOYSA-N 0.000 description 1
- HXJUTPCZVOIRIF-UHFFFAOYSA-N sulfolane Chemical compound O=S1(=O)CCCC1 HXJUTPCZVOIRIF-UHFFFAOYSA-N 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 239000011271 tar pitch Substances 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- RAOIDOHSFRTOEL-UHFFFAOYSA-N tetrahydrothiophene Chemical compound C1CCSC1 RAOIDOHSFRTOEL-UHFFFAOYSA-N 0.000 description 1
- LFQCEHFDDXELDD-UHFFFAOYSA-N tetramethyl orthosilicate Chemical compound CO[Si](OC)(OC)OC LFQCEHFDDXELDD-UHFFFAOYSA-N 0.000 description 1
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- WRECIMRULFAWHA-UHFFFAOYSA-N trimethyl borate Chemical compound COB(OC)OC WRECIMRULFAWHA-UHFFFAOYSA-N 0.000 description 1
- 229920006337 unsaturated polyester resin Polymers 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- 229920001567 vinyl ester resin Polymers 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
Description
本発明は、リチウム二次電池用複合活物質とアクリル酸系重合体を含むリチウム二次電池用負極材およびその製造方法、並びに、リチウム二次電池に関する。 The present invention relates to a negative electrode material for a lithium secondary battery containing a composite active material for a lithium secondary battery and an acrylic acid polymer, a method for producing the same, and a lithium secondary battery.
電子材料の小型軽量化、および、ＨＥＶまたはＥＶの開発の進展に伴い、大容量、高速充放電特性、良好なサイクル特性、かつ安全性に優れた電池の開発の要望は益々増大している。なかでも、リチウムイオン二次電池（リチウム二次電池）が最も有望な電池として注目されている。 As electronic materials become smaller and lighter and HEV or EV development progresses, the demand for development of batteries with high capacity, high-speed charge / discharge characteristics, good cycle characteristics, and excellent safety is increasing. Among these, a lithium ion secondary battery (lithium secondary battery) has attracted attention as the most promising battery.
しかしながら、優れた性能を示すリチウム二次電池が開発される前提として、各種性能に優れた負極材料、正極材料、電解液、セパレータ、または集電体などが開発され、且つ、それらの特性を十分に生した電池設計がなされなくてはならない。 However, as a premise for the development of lithium secondary batteries that exhibit excellent performance, negative electrode materials, positive electrode materials, electrolytes, separators, or current collectors that are excellent in various performances have been developed, and their characteristics are sufficient. The battery design must be made.
なかでも、負極材料は基本的な電池特性を決定するものであるため、充放電容量などの特性がより優れる材料の開発が活発に行われている。例えば、特許文献１では、大充放電容量、高速充放電特性、および良好なサイクル特性を併せ持ったリチウム二次電池の作製が可能なリチウム二次電池用複合活物質、並びに、その製造方法が開示されている。同様に金属元素を添加することで、高い充放電容量を有しながら、タールピッチ由来の炭素質を含ませたリチウム二次電池用複合活物質が開示されている（例えば特許文献２参照）。 Among these, since the negative electrode material determines basic battery characteristics, materials having more excellent characteristics such as charge / discharge capacity are being actively developed. For example, Patent Document 1 discloses a composite active material for a lithium secondary battery capable of producing a lithium secondary battery having both large charge / discharge capacity, high-speed charge / discharge characteristics, and good cycle characteristics, and a manufacturing method thereof. Has been. Similarly, a composite active material for a lithium secondary battery containing a carbonaceous material derived from tar pitch while having a high charge / discharge capacity by adding a metal element is disclosed (for example, see Patent Document 2).
しかし、金属元素を添加したリチウム二次電池用複合活物質は、充放電容量などの特性が優れるが、充放電サイクル寿命が低下し易い問題があった。そのため、ソフトカーボンを含ませた複合活物質により、充放電サイクル寿命を改善した複合活物質も開示されている（例えば特許文献３参照）。 However, the composite active material for a lithium secondary battery to which a metal element is added has excellent characteristics such as charge / discharge capacity, but has a problem that the charge / discharge cycle life tends to be reduced. Therefore, a composite active material whose charge / discharge cycle life is improved by a composite active material containing soft carbon is also disclosed (for example, see Patent Document 3).
しかしながら、これらの方法でも長いサイクルを実施した場合には、不可逆な膨張の抑制は不十分であった。 However, even in these methods, when a long cycle was carried out, the irreversible expansion was not sufficiently suppressed.
また、リチウム二次電池の電極は、通常、バインダーを溶媒に溶解させたバインダー溶液、または分散媒に分散させた分散液に対して、リチウム二次電池用複合活物質を混合したスラリーを集電体に塗布し、溶媒や分散媒を乾燥などの方法で除去して、リチウム二次電池用複合活物質及び集電体の各間を結着させて製造される。 Also, an electrode of a lithium secondary battery usually collects a slurry obtained by mixing a composite active material for a lithium secondary battery with a binder solution in which a binder is dissolved in a solvent or a dispersion liquid in which a binder is dispersed. It is applied to the body, the solvent and the dispersion medium are removed by a method such as drying, and the composite active material for the lithium secondary battery and the current collector are bound together.
バインダーとしては、ポリビニリデンフルオライド（ＰＶＤＦ）が工業的に多用されている。例えば、特許文献４，５においては、ＰＶＤＦをＮ−メチルピロリドンなどに溶解して電極用バインダー組成物とした後、リチウム二次電池用複合活物質を混合してスラリーとし、これを集電体に塗布、乾燥してリチウム二次電池用電極を形成している。しかしながら、フッ素系ポリマーのＰＶＤＦは、リチウム二次電池用複合活物質に対する隠蔽性が少ないという長所を有しながら、結着力と柔軟性が不足している。このため、バインダーを多量に使用する必要があり、バインダーがリチウム二次電池用複合活物質を隠蔽してしまうという問題がある。また、バインダーを多量に使用するために、電極におけるリチウム二次電池用複合活物質の割合が減少するという問題もある。さらに、ＰＶＤＦでは、電極の寿命特性や高率放電特性が低下するという問題もある。 As the binder, polyvinylidene fluoride (PVDF) is widely used industrially. For example, in Patent Documents 4 and 5, after PVDF is dissolved in N-methylpyrrolidone or the like to form a binder composition for an electrode, a composite active material for a lithium secondary battery is mixed to form a slurry, which is used as a current collector. The electrode for lithium secondary battery is formed by coating and drying. However, PVDF, which is a fluorine-based polymer, has the advantage of low concealability with respect to the composite active material for lithium secondary batteries, but lacks binding power and flexibility. For this reason, it is necessary to use a binder in large quantities, and there is a problem that the binder conceals the composite active material for a lithium secondary battery. In addition, since the binder is used in a large amount, there is a problem that the ratio of the composite active material for the lithium secondary battery in the electrode is reduced. Furthermore, PVDF also has a problem that the life characteristics of the electrode and the high rate discharge characteristics deteriorate.
一方、近年、電池の使用安全性の点から、充放電を繰り返した後においても電極材料の体積が膨張しないことが求められている。電極材料の体積膨張が大きいと、電解液の液漏れの発生や、電池の寿命の低下が引き起こされる。また、近年、電池材料に対する要求特性が非常に高まってきており、サイクル特性に対する要求水準もより一層高まっている。 On the other hand, in recent years, it has been demanded that the volume of the electrode material does not expand even after repeated charging and discharging from the viewpoint of safety of use of the battery. When the volume expansion of the electrode material is large, the occurrence of leakage of the electrolytic solution and the reduction of the battery life are caused. In recent years, the required characteristics for battery materials have increased greatly, and the required level for cycle characteristics has further increased.
本発明者らは、上述した特許文献１に記載の製造方法に従って、リチウムイオンと化合可能な電池活物質としてシリコンを含むリチウム二次電池用複合活物質を製造して、得られたリチウム二次電池用複合活物質を含む電極材料（例えば、負極材料）の膨張特性について評価を行ったところ、数サイクル後にはリチウムとシリコンの合金化に伴う理論的な膨張以上の不可逆的な大きな体積の膨張が認められ、更なる改良が必要であることを知見した。また、サイクル特性に関しては、従来の要求レベルは満たすものの、昨今のより高い要求レベルを満たしておらず、更なる改良が必要であった。 The inventors of the present invention manufactured a lithium secondary battery composite active material containing silicon as a battery active material that can be combined with lithium ions in accordance with the manufacturing method described in Patent Document 1 described above. When the expansion characteristics of electrode materials (for example, negative electrode materials) containing composite active materials for batteries were evaluated, irreversibly large volume expansion beyond the theoretical expansion associated with the alloying of lithium and silicon after several cycles It was found that further improvement is necessary. In addition, regarding the cycle characteristics, although the conventional requirement level is satisfied, the higher requirement level of recent times is not satisfied, and further improvement is necessary.
本発明は、上記実情に鑑みて、充放電を繰り返した後でも体積膨張が抑制された電極材料の作製が可能で、かつ、優れたサイクル特性を示すリチウム二次電池の作製が可能なリチウム二次電池用複合活物質及びアクリル酸系重合体を含むリチウム二次電池用負極材並びにその製造方法を提供することを課題とする。 In view of the above circumstances, the present invention is capable of producing an electrode material in which volume expansion is suppressed even after repeated charge and discharge, and capable of producing a lithium secondary battery exhibiting excellent cycle characteristics. It is an object of the present invention to provide a negative electrode material for a lithium secondary battery including a composite active material for a secondary battery and an acrylic acid polymer, and a method for producing the same.
また、本発明は、上記リチウム二次電池用複合活物質とアクリル酸系重合体を含むリチウム二次電池用負極材を含むリチウム二次電池を提供することも課題とする。 Another object of the present invention is to provide a lithium secondary battery including the above-described composite active material for lithium secondary batteries and an anode material for lithium secondary batteries containing an acrylic acid polymer.
本発明者らは、従来技術について鋭意検討を行った結果、以下の構成によって上記課題を解決できることを見出した。
（１）黒鉛成分、ハードカーボン、ソフトカーボン、及びリチウムイオンと化合可能な電池活物質を含む、リチウム二次電池用複合活物質並びにアクリル酸系重合体を含むリチウム二次電池用負極材。
（２）リチウム二次電池用複合活物質におけるリチウムイオンと化合可能な電池活物質の平均粒径（Ｄ５０）が０．０１〜０．６μｍ、Ｄ９０が０．０１〜１．０μｍであり、ＢＥＴ法によるＢＥＴ比表面積が４０〜３００ｍ２／ｇである（１）に記載のリチウム二次電池用負極材。
（３）リチウム二次電池用複合活物質では黒鉛成分１５〜６５質量部、ハードカーボン５〜４０質量部、ソフトカーボン５〜６０質量部、リチウムイオンと化合可能な電池活物質５〜８０質量部である、（１）又は（２）に記載のリチウム二次電池用負極材。
（４）リチウム二次電池用複合活物質における黒鉛成分は、ＩＣＰ発光分光分析法による２６元素（Ａｌ、Ｃａ、Ｃｒ、Ｆｅ、Ｋ、Ｍｇ、Ｍｎ、Ｎａ、Ｎｉ、Ｖ、Ｚｎ、Ｚｒ、Ａｇ、Ａｓ、Ｂａ、Ｂｅ、Ｃｄ、Ｃｏ、Ｃｕ、Ｍｏ、Ｐｂ、Ｓｂ、Ｓｅ、Ｔｈ、Ｔｌ、Ｕ）の不純物半定量値より求めた純度が９９．９重量％以上（１０００ｐｐｍ以下）で酸素フラスコ燃焼法によるイオンクロマトグラフィー（ＩＣ）測定法によるＳ量が０．３重量％以下、及び／又はＢＥＴ比表面積が２００ｍ２／ｇ以下である（１）〜（３）のいずれかに記載のリチウム二次電池用負極材。
（５）リチウム二次電池用複合活物質ではリチウムイオンと化合可能な電池活物質が、０．２μｍ以下の厚みの黒鉛薄層の間に挟まれた構造であり、その構造が積層および／または網目状に広がっており、該黒鉛薄層が活物質粒子の表面付近で湾曲して活物質粒子を覆っている（１）〜（４）のいずれかに記載のリチウム二次電池用負極材。
（６）アクリル酸系重合体の重量平均分子量が１００，０００〜３，０００，０００、中和率１０〜１００％である（１）〜（５）のいずれかに記載のリチウム二次電池用負極材
（７）リチウム二次電池用複合活物質１００質量部に対して、アクリル酸系重合体１〜５０質量部の含有する（１）〜（６）のいずれかに記載のリチウム二次電池用負極材
（８）黒鉛成分、および、リチウムイオンと化合可能な電池活物質を含む第１混合物に球形化処理を施す球形化工程と、
球形化処理が施された前記第１混合物に対して加熱処理を施す第１加熱工程と、
前記第１加熱工程で得られた焼成物とソフトカーボンの前駆体とを混合して第２混合物を得る混合工程と、
前記第２混合物に対して加熱処理を施す第２加熱工程によりリチウム二次電池用複合活物質を製造した後、アクリル酸系重合体を混合する（１）〜（７）のいずれかに記載のリチウム二次電池用負極材の製造方法。
（９）黒鉛成分、および、リチウムイオンと化合可能な電池活物質を含む第１混合物に球形化処理を施す球形化工程と、
球形化処理が施された第１混合物とソフトカーボンの前駆体とを混合して第３混合物を得る混合工程と、
前記第３混合物に対して加熱処理を施す加熱工程によりリチウム二次電池用複合活物質を製造した後、アクリル酸系重合体を混合する（１）〜（７）のいずれかに記載のリチウム二次電池用負極材の製造方法。
（１０）黒鉛成分、ハードカーボン、ソフトカーボンの前駆体、及びリチウムイオンと化合可能な電池活物質を含む第４混合物に球形化処理を施す球形化工程と、
球形化処理が施された前記第４混合物に対して加熱処理を施す加熱工程によりリチウム二次電池用複合活物質を製造した後、アクリル酸系重合体を混合する（１）〜（７）のいずれかに記載のリチウム二次電池用負極材の製造方法。
（１１）前記ソフトカーボンンの前駆体が、石炭系ピッチ、石油系ピッチ、メソフェーズピッチ、コークス、低分子重質油、およびそれらの誘導体からなる群から選択される少なくとも１つである、（８）〜（１０）のいずれかに記載のリチウム二次電池用負極材の製造方法。
（１２）前記、第２〜４混合物に対して、加熱処理を施す加熱工程において、加熱温度４００℃以上、昇温速度を１℃／ｍｉｎ以上にする（８）〜（１１）のいずれかに記載のリチウム二次電池用負極材の製造方法。
（１３）（１）〜（７）のいずれかに記載のリチウム二次電池用負極材を含むリチウム二次電池。
As a result of intensive studies on the prior art, the present inventors have found that the above problem can be solved by the following configuration.
(1) A negative active material for a lithium secondary battery, comprising a composite active material for a lithium secondary battery, including a graphite component, hard carbon, soft carbon, and a battery active material that can be combined with lithium ions, and an acrylic polymer.
(2) The average particle diameter (D50) of the battery active material that can be combined with lithium ions in the composite active material for a lithium secondary battery is 0.01 to 0.6 μm, D90 is 0.01 to 1.0 μm, and BET The negative electrode material for a lithium secondary battery according to (1), wherein the BET specific surface area according to the method is 40 to 300 m 2 / g.
(3) 15 to 65 parts by mass of graphite component, 5 to 40 parts by mass of hard carbon, 5 to 60 parts by mass of soft carbon, and 5 to 80 parts by mass of battery active material that can be combined with lithium ions in the composite active material for lithium secondary battery The negative electrode material for a lithium secondary battery according to (1) or (2).
(4) The graphite component in the composite active material for lithium secondary battery is composed of 26 elements (Al, Ca, Cr, Fe, K, Mg, Mn, Na, Ni, V, Zn, Zr, Ag by ICP emission spectroscopy). , As, Ba, Be, Cd, Co, Cu, Mo, Pb, Sb, Se, Th, Tl, U) The purity obtained from the semi-quantitative value of impurities is 99.9 wt% or more (1000 ppm or less) Lithium according to any one of (1) to (3), wherein the amount of S by an ion chromatography (IC) measurement method by a combustion method is 0.3 wt% or less and / or the BET specific surface area is 200 m 2 / g or less. Secondary battery negative electrode material.
(5) The composite active material for a lithium secondary battery has a structure in which a battery active material that can combine with lithium ions is sandwiched between thin graphite layers having a thickness of 0.2 μm or less, and the structure is laminated and / or The negative electrode material for a lithium secondary battery according to any one of (1) to (4), wherein the negative electrode material spreads in a network and the thin graphite layer is curved near the surface of the active material particles to cover the active material particles.
(6) The lithium secondary battery according to any one of (1) to (5), wherein the acrylic polymer has a weight average molecular weight of 100,000 to 3,000,000 and a neutralization rate of 10 to 100%. Negative electrode material (7) The lithium secondary battery according to any one of (1) to (6), which is contained in 1 to 50 parts by mass of an acrylic polymer based on 100 parts by mass of the composite active material for a lithium secondary battery Negative electrode material (8) spheronization step of spheronizing a first mixture containing a graphite component and a battery active material that can be combined with lithium ions;
A first heating step of performing a heat treatment on the first mixture subjected to the spheroidization treatment;
A mixing step of mixing the fired product obtained in the first heating step and a precursor of soft carbon to obtain a second mixture;
The composite active material for a lithium secondary battery is manufactured by a second heating step in which heat treatment is performed on the second mixture, and then the acrylic acid polymer is mixed (1) to (7). A method for producing a negative electrode material for a lithium secondary battery.
(9) A spheronization step of subjecting the first mixture containing a graphite component and a battery active material that can be combined with lithium ions to a spheronization treatment;
A mixing step of mixing a spheroidized first mixture and a soft carbon precursor to obtain a third mixture;
The lithium secondary battery according to any one of (1) to (7), wherein a composite active material for a lithium secondary battery is manufactured by a heating step of performing a heat treatment on the third mixture, and then an acrylic acid polymer is mixed. The manufacturing method of the negative electrode material for secondary batteries.
(10) A spheronization step of spheronizing a fourth mixture containing a graphite component, a hard carbon, a precursor of soft carbon, and a battery active material that can be combined with lithium ions;
After manufacturing the composite active material for lithium secondary batteries by the heating process which heat-processes with respect to the said 4th mixture in which the spheroidization process was performed, acrylic acid polymer is mixed (1)-(7) The manufacturing method of the negative electrode material for lithium secondary batteries in any one.
(11) The soft carbonone precursor is at least one selected from the group consisting of coal-based pitch, petroleum-based pitch, mesophase pitch, coke, low molecular weight heavy oil, and derivatives thereof. )-(10) The manufacturing method of the negative electrode material for lithium secondary batteries in any one of.
(12) In any one of (8) to (11), in the heating step of performing heat treatment on the second to fourth mixtures, the heating temperature is 400 ° C. or higher and the temperature rising rate is 1 ° C./min or higher. The manufacturing method of the negative electrode material for lithium secondary batteries of description.
(13) A lithium secondary battery comprising the negative electrode material for a lithium secondary battery according to any one of (1) to (7).
本発明によれば、充放電を繰り返した後でも体積膨張が抑制された電極材料の作製が可能で、かつ、優れたサイクル特性を示すリチウム二次電池の作製が可能なリチウム二次電池用複合活物質及びアクリル酸系重合体を含むリチウム二次電池用負極材並びにその製造方法を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the composite for lithium secondary batteries which can produce the electrode material by which volume expansion was suppressed even after repeating charging / discharging, and can produce the lithium secondary battery which shows the outstanding cycling characteristics is possible. A negative electrode material for a lithium secondary battery containing an active material and an acrylic acid polymer and a method for producing the same can be provided.
また、本発明によれば、上記リチウム二次電池用複合活物質とバインダーとしてのアクリル酸系重合体を含むリチウム二次電池用負極材のリチウム二次電池を提供することもできる。 Moreover, according to this invention, the lithium secondary battery of the negative electrode material for lithium secondary batteries containing the said composite active material for lithium secondary batteries and an acrylic acid type polymer as a binder can also be provided.
最初に、本発明のリチウム二次電池用負極材におけるリチウム二次電池用複合活物質およびその製造方法について詳述する。 First, the composite active material for a lithium secondary battery in the negative electrode material for a lithium secondary battery of the present invention and the production method thereof will be described in detail.
本発明のリチウム二次電池用負極材におけるリチウム二次電池用複合活物質は、黒鉛成分、ハードカーボン、ソフトカーボン、及びリチウムイオンと化合可能な電池活物質とを含むリチウム二次電池用複合活物質である。 The composite active material for lithium secondary battery in the negative electrode material for lithium secondary battery of the present invention is a composite active material for lithium secondary battery comprising a graphite component, hard carbon, soft carbon, and a battery active material that can be combined with lithium ions. It is a substance.
以下では、まず、リチウム二次電池用複合活物質に含まれる各成分について詳述し、その後、その製造方法について詳述する。
＜黒鉛成分＞
黒鉛成分としては、天然黒鉛材、人造黒鉛等が挙げられ、その中でも通常グラファイトと呼ばれる天然黒鉛を薄片化した薄片化黒鉛が好ましい。
Below, each component contained in the composite active material for lithium secondary batteries is explained in full detail first, and the manufacturing method is explained in full detail after that.
<Graphite component>
Examples of the graphite component include natural graphite materials and artificial graphite. Among them, exfoliated graphite obtained by exfoliating natural graphite usually called graphite is preferable.
本明細書においては、薄片化黒鉛とは、グラフェンシートの積層数が４００層以下の黒鉛を意図する。なお、グラフェンシートは主にファンデルワールス力によって互いに結合している。 In the present specification, exfoliated graphite means graphite having 400 or less graphene sheets stacked. The graphene sheets are bonded to each other mainly by van der Waals force.
薄片化黒鉛におけるグラフェンシートの積層数は、リチウムイオンと化合可能な電池活物質と薄片化黒鉛とがより均一に分散し、リチウム二次電池用複合活物質を用いた電池材料の膨張がより抑制される、および／または、リチウム二次電池のサイクル特性がより優れる点で（以後、単に「本発明の効果がより優れる点」）で、３００層以下が好ましく、２００層以下がより好ましく、１５０層以下がさらに好ましい。取り扱い性の点からは、５層以上が好ましい。 The number of graphene sheets laminated in exfoliated graphite is such that the battery active material that can combine with lithium ions and exfoliated graphite are more evenly dispersed, and the expansion of the battery material using the composite active material for lithium secondary batteries is further suppressed. And / or in terms of more excellent cycle characteristics of the lithium secondary battery (hereinafter simply referred to as “the effect of the present invention is more excellent”), preferably 300 layers or less, more preferably 200 layers or less, 150 More preferred is a layer or less. From the viewpoint of handleability, 5 or more layers are preferable.
なお、薄片化黒鉛におけるグラフェンシートの積層数は透過型電子顕微鏡（ＴＥＭ）を用いて測定することができる。 The number of graphene sheets stacked in exfoliated graphite can be measured using a transmission electron microscope (TEM).
薄片化黒鉛の平均厚みは、本発明の効果がより優れる点で、４０ｎｍ以下が好ましく、２２ｎｍ以下がより好ましい。下限は特に制限されないが、製造手順が煩雑になることから、通常、４ｎｍ以上である場合が多い。 The average thickness of exfoliated graphite is preferably 40 nm or less, and more preferably 22 nm or less, in that the effect of the present invention is more excellent. The lower limit is not particularly limited, but is usually 4 nm or more because the production procedure becomes complicated.
なお、上記平均厚みの測定方法としては、電子顕微鏡観察（ＴＥＭ）によって薄片化黒鉛を観察し、薄片化黒鉛中の積層したグラフェンシートの層の厚みを１０個以上測定して、その値を算術平均することによって、平均厚みが得られる。 The average thickness is measured by observing exfoliated graphite by electron microscope observation (TEM), measuring the thickness of 10 or more layers of laminated graphene sheets in exfoliated graphite, and calculating the value as arithmetic. By averaging, an average thickness is obtained.
薄片化黒鉛は、黒鉛化合物をその層面間において剥離し薄片化して得られる。 The exfoliated graphite is obtained by exfoliating a graphite compound between its layer surfaces.
薄片化黒鉛としては、例えば、いわゆる膨張黒鉛が挙げられる。 Examples of exfoliated graphite include so-called expanded graphite.
膨張黒鉛中には、黒鉛が含まれており、例えば、鱗片状黒鉛を濃硫酸や硝酸や過酸化水素水等で処理し、グラフェンシートの隙間にこれら薬液をインターカレートさせ、さらに加熱してインターカレートされた薬液が気化する際にグラフェンシートの隙間を広げることによって得られる。なお、後述するように、膨張黒鉛を出発原料として所定のリチウム二次電池用複合活物質を製造することができる。つまり、リチウム二次電池用複合活物質中の黒鉛成分として、膨張黒鉛を使用することもできる。 The expanded graphite contains graphite, for example, scaly graphite is treated with concentrated sulfuric acid, nitric acid, hydrogen peroxide, etc., and these chemicals are intercalated into the gaps in the graphene sheet, and further heated. It is obtained by widening the gap between the graphene sheets when the intercalated chemical solution is vaporized. As will be described later, a predetermined composite active material for a lithium secondary battery can be produced using expanded graphite as a starting material. That is, expanded graphite can also be used as the graphite component in the composite active material for a lithium secondary battery.
また、黒鉛成分として、球形化処理が施された膨張黒鉛も挙げられる。球形化処理の手順は後段で詳述する。なお、後述するように、膨張黒鉛に球形化処理を実施する際には、他の成分（例えば、ハードカーボン及びソフトカーボンの前駆体、リチウムイオンと化合可能な電池活物質など）と共に、球形化処理が実施されてもよい。 Examples of the graphite component include expanded graphite that has been spheroidized. The procedure of the spheronization process will be described in detail later. As will be described later, when the expanded graphite is subjected to spheronization treatment, it is spheroidized together with other components (for example, hard carbon and soft carbon precursors, battery active materials that can be combined with lithium ions). Processing may be performed.
なお、黒鉛成分の比表面積は特に制限されないが、本発明の効果がより優れる点で、１０ｍ２／ｇ以上が好ましく、２０ｍ２／ｇ以上がより好ましい。上限は特に制限されないが、製造の手順が煩雑となり、合成が困難な点で、比表面積は２００ｍ２／ｇ以下が好ましい。 The specific surface area of the graphite component is not particularly limited, but is preferably 10 m 2 / g or more and more preferably 20 m 2 / g or more in terms of more excellent effects of the present invention. The upper limit is not particularly limited, but the specific surface area is preferably 200 m 2 / g or less in that the production procedure is complicated and the synthesis is difficult.
なお、黒鉛成分の比表面積は、窒素吸着によるＢＥＴ法（ＪＩＳ Ｚ ８８３０、一点法）を用いて測定したものである。 In addition, the specific surface area of a graphite component is measured using the BET method (JIS Z 8830, one point method) by nitrogen adsorption.
黒鉛成分は、純度９９．９重量％以上、若しくは不純物量１０００ｐｐｍ以下であり、Ｓ量が０．３重量％以下及び／又はＢＥＴ比表面積が２００ｍ２／ｇ以下であることが好ましい。純度が９９．９重量％よりも少なく、若しくは不純物量が１０００ｐｐｍよりも多いと、不純物由来のＳＥＩ形成による不可逆容量が多くなるため、初回の充電容量に対する放電容量である初回充放電効率が低くなる傾向がある。また、Ｓ量が０．３重量％よりも高くなると同様に不可逆容量が高くなるため、初回充放電効率が低くなる。さらに好ましくは、Ｓ量が０．１重量％以下が好ましい。黒鉛成分のＢＥＴ比表面積が４０ｍ２／ｇよりも高いと、電解液との反応する面積が多くなるため、初回充放電効率が低くなる。 The graphite component preferably has a purity of 99.9 wt% or more, or an impurity amount of 1000 ppm or less, an S amount of 0.3 wt% or less, and / or a BET specific surface area of 200 m 2 / g or less. If the purity is less than 99.9% by weight or the amount of impurities is more than 1000 ppm, the irreversible capacity due to the formation of SEI derived from impurities increases, so the initial charge / discharge efficiency, which is the discharge capacity with respect to the initial charge capacity, decreases. Tend. Moreover, since the irreversible capacity | capacitance similarly becomes high when S amount becomes higher than 0.3 weight%, initial charge / discharge efficiency becomes low. More preferably, the amount of S is preferably 0.1% by weight or less. When the BET specific surface area of the graphite component is higher than 40 m 2 / g, the area where the graphite component reacts increases, and the initial charge / discharge efficiency decreases.
不純物の測定は、ＩＣＰ発光分光分析法により、以下の２６元素（Ａｌ、Ｃａ、Ｃｒ、Ｆｅ、Ｋ、Ｍｇ、Ｍｎ、Ｎａ、Ｎｉ、Ｖ、Ｚｎ、Ｚｒ、Ａｇ、Ａｓ、Ｂａ、Ｂｅ、Ｃｄ、Ｃｏ、Ｃｕ、Ｍｏ、Ｐｂ、Ｓｂ、Ｓｅ、Ｔｈ、Ｔｌ、Ｕ）の不純物半定量値により測定する。また、Ｓ量は、酸素フラスコ燃焼法で燃焼吸収処理した後、フィルター濾過してイオンクロマトグラフィー（ＩＣ）測定により行う。
＜ハードカーボン＞
ハードカーボンとは、不活性雰囲気中で加熱処理を施した時に、黒鉛構造（炭素原子が構成する六角網平面が規則性をもって積層した構造）の発達が抑えられた不規則な構造を有するカーボンであり、難黒鉛化性炭素とも言われる。また、ハードカーボンとは、３０００℃で熱処理しても黒鉛化しにくい炭素材料でもある。
Impurity is measured by ICP emission spectroscopic analysis using the following 26 elements (Al, Ca, Cr, Fe, K, Mg, Mn, Na, Ni, V, Zn, Zr, Ag, As, Ba, Be, Cd. , Co, Cu, Mo, Pb, Sb, Se, Th, Tl, U). Further, the amount of S is measured by ion chromatography (IC) measurement after filtering and filtering by an oxygen flask combustion method.
<Hard carbon>
Hard carbon is a carbon that has an irregular structure in which the development of a graphite structure (a structure in which hexagonal network planes composed of carbon atoms are laminated with regularity) is suppressed when heat treatment is performed in an inert atmosphere. Yes, it is also called non-graphitizable carbon. Hard carbon is also a carbon material that is difficult to graphitize even when heat-treated at 3000 ° C.
ここでハードカーボンは、樹脂または樹脂組成物などの前駆体を炭化処理して得ることが好ましい。炭化処理することで、樹脂または樹脂組成物が炭化処理され、リチウムイオン二次電池用炭素材として用いることができる。ハードカーボンの原材料（前駆体）となる、樹脂又は樹脂組成物としては、高分子化合物など（例えば、熱硬化性樹脂、熱可塑性樹脂）が挙げられる。熱硬化性樹脂としては特に限定されず、例えば、ノボラック型フェノール樹脂、レゾール型フェノール樹脂などのフェノール樹脂；ビスフェノール型エポキシ樹脂、ノボラック型エポキシ樹脂などのエポキシ樹脂；メラミン樹脂；尿素樹脂；アニリン樹脂；シアネート樹脂；フラン樹脂；ケトン樹脂；不飽和ポリエステル樹脂；ウレタン樹脂などが挙げられる。また、これらが種々の成分で変性された変性物を用いることもできる。 Here, the hard carbon is preferably obtained by carbonizing a precursor such as a resin or a resin composition. By carbonizing, the resin or resin composition is carbonized and can be used as a carbon material for a lithium ion secondary battery. Examples of the resin or resin composition that is the raw material (precursor) of the hard carbon include polymer compounds (for example, thermosetting resins and thermoplastic resins). The thermosetting resin is not particularly limited. For example, a phenol resin such as a novolac type phenol resin or a resol type phenol resin; an epoxy resin such as a bisphenol type epoxy resin or a novolac type epoxy resin; a melamine resin; a urea resin; Examples include cyanate resins; furan resins; ketone resins; unsaturated polyester resins; urethane resins. In addition, modified products obtained by modifying these with various components can also be used.
また、熱可塑性樹脂としては、特に限定されず、例えば、ポリエチレン、ポリスチレン、アクリロニトリル−スチレン（ＡＳ）樹脂、アクリロニトリル−ブタジエン−スチレン（ＡＢＳ）樹脂、ポリプロピレン、ポリエチレンテレフタレート、ポリカーボネート、ポリアセタール、ポリフェニレンエーテル、ポリブチレンテレフタレート、ポリフェニレンサルファイド、ポリサルホン、ポリエーテルサルホン、ポリエーテルエーテルケトンなどが挙げられる。 The thermoplastic resin is not particularly limited. For example, polyethylene, polystyrene, acrylonitrile-styrene (AS) resin, acrylonitrile-butadiene-styrene (ABS) resin, polypropylene, polyethylene terephthalate, polycarbonate, polyacetal, polyphenylene ether, poly Examples include butylene terephthalate, polyphenylene sulfide, polysulfone, polyethersulfone, and polyetheretherketone.
これらのうち１種または２種以上を組み合わせて用いることができる。 Among these, one kind or a combination of two or more kinds can be used.
これらの中でも特に好ましいハードカーボンの原材料（前駆体）は、ノボラック型フェノール樹脂、レゾール型フェノール樹脂などのフェノール樹脂等が挙げられる。 Among these, particularly preferred hard carbon raw materials (precursors) include phenolic resins such as novolac type phenolic resins and resol type phenolic resins.
ハードカーボンの前駆体の形状は特に制限されず、粉状、板状、粒状、繊維状、塊状、球状など、あらゆる形状のものが使用可能である。これらの前駆体は、各種成分を混合する際に使用する溶剤に溶解することが好ましい。 The shape of the hard carbon precursor is not particularly limited, and any shape such as powder, plate, granule, fiber, lump, and sphere can be used. These precursors are preferably dissolved in a solvent used when various components are mixed.
使用されるハードカーボンの前駆体の重量平均分子量としては、本発明の効果がより優れる点で１０００以上が好ましく、１，０００，０００以下がより好ましい
＜ソフトカーボン＞
ソフトカーボンとは、不活性雰囲気中で加熱処理を施した時、黒鉛構造が発達し易いカーボンであり、易黒鉛化性炭素とも言われる。また、ソフトカーボンは、２８００〜３０００℃で熱処理した際に黒鉛化する炭素材料でもある。
The weight average molecular weight of the hard carbon precursor used is preferably 1000 or more and more preferably 1,000,000 or less in terms of more excellent effects of the present invention <soft carbon>
Soft carbon is carbon that easily develops a graphite structure when heat-treated in an inert atmosphere, and is also referred to as graphitizable carbon. Soft carbon is also a carbon material that graphitizes when heat-treated at 2800 to 3000 ° C.
ここでソフトカーボンは、樹脂または樹脂組成物などの前駆体を炭化処理して得ることが好ましい。炭化処理することで、樹脂または樹脂組成物が炭化処理され、リチウムイオン二次電池用炭素材として用いることができる。ソフトカーボンの原材料（前駆体）となる、樹脂又は樹脂組成物としては、特に限定されず、石炭系ピッチ（例えば、コールタールピッチ）、石油系ピッチ、メソフェーズピッチ、コークス、低分子重質油、またはそれらの誘導体などが挙げられ、石炭系ピッチ（例えば、コールタールピッチ）、石油系ピッチ、メソフェーズピッチ、コークス、低分子重質油、またはそれらの誘導体などが好ましい。なかでも、本発明の効果がより優れる点で、石炭系ピッチなどの前駆体から得られるソフトカーボンが好ましい。 Here, the soft carbon is preferably obtained by carbonizing a precursor such as a resin or a resin composition. By carbonizing, the resin or resin composition is carbonized and can be used as a carbon material for a lithium ion secondary battery. The resin or resin composition that is the raw material (precursor) of the soft carbon is not particularly limited, and coal-based pitch (for example, coal tar pitch), petroleum-based pitch, mesophase pitch, coke, low molecular weight heavy oil, Alternatively, derivatives thereof are exemplified, and coal-based pitch (for example, coal tar pitch), petroleum-based pitch, mesophase pitch, coke, low molecular weight heavy oil, or derivatives thereof are preferable. Especially, the soft carbon obtained from precursors, such as coal pitch, is preferable at the point which the effect of this invention is more excellent.
ソフトカーボンの前駆体の形状は特に制限されず、粉状、板状、粒状、繊維状、塊状、球状など、あらゆる形状のものが使用可能である。これらの前駆体は、各種成分を混合する際に使用する溶剤に溶解することが好ましい。 The shape of the soft carbon precursor is not particularly limited, and any shape such as powder, plate, granule, fiber, lump, and sphere can be used. These precursors are preferably dissolved in a solvent used when various components are mixed.
使用されるソフトカーボンの前駆体の重量平均分子量としては、本発明の効果がより優れる点で１０００以上が好ましく、１，０００，０００以下がより好ましい
＜リチウムイオンと化合可能な電池活物質＞
リチウムイオンと化合可能な電池活物質（以後、単に「電池活物質」とも称する）は、リチウムイオンと化合して、リチウムイオンを吸蔵および放出し得る物質（例えば、金属、金属の炭化物、窒化物、酸化物など）であればよい。例えば、リチウムイオンの吸収および放出が可能な金属もしくは非金属、または、リチウムと合金化可能な金属酸化物である。
The weight average molecular weight of the soft carbon precursor used is preferably 1000 or more, more preferably 1,000,000 or less in terms of more excellent effects of the present invention <battery active material that can be combined with lithium ions>.
A battery active material that can be combined with lithium ions (hereinafter, also simply referred to as “battery active material”) is a material that can combine with lithium ions to absorb and release lithium ions (eg, metal, metal carbide, nitride). Or oxide). For example, a metal or nonmetal capable of absorbing and releasing lithium ions, or a metal oxide capable of being alloyed with lithium.
電池活物質は、周期表の１３族の元素、周期表の１４族の元素、周期表の１５族の元素、マグネシウム、および、マンガンからなる群から選ばれる少なくとも１種の元素を含有することが好ましく、より具体的には、Ｓｉ、Ｓｎ、Ａｌ、Ｓｂ、Ｚｎ、Ｂｉ、Ｃｄ、Ｐｂ、Ｉｎ、Ａｇ、Ｇａ、Ｇｅなどの金属（リチウムと合金化可能な金属）もしくはこれら金属を含む合金（例えば、Ｓｉ合金、Ｓｂ合金、Ｓｎ合金、Ｉｎ合金）、または、ＳｎＯ、ＳｎＯ２などの金属酸化物（リチウムと合金化可能な金属酸化物）などが挙げられる。なかでも、得られるリチウム二次電池用複合活物質を用いて得られるリチウム二次電池の放電容量およびサイクル特性がより優れる点で、電池活物質がＳｉ、Ｓｎ、Ａｌ、Ｓｂ、およびＩｎからなる群から選ばれる少なくとも１種の元素を含有することが好ましく、Ｓｉ、Ｓｎの元素を含有することがより好ましい。 The battery active material may contain at least one element selected from the group consisting of Group 13 elements of the periodic table, Group 14 elements of the periodic table, Group 15 elements of the periodic table, magnesium, and manganese. More specifically, more specifically, a metal such as Si, Sn, Al, Sb, Zn, Bi, Cd, Pb, In, Ag, Ga, or Ge (a metal that can be alloyed with lithium) or an alloy containing these metals ( For example, a Si alloy, a Sb alloy, a Sn alloy, an In alloy, or a metal oxide such as SnO or SnO 2 (a metal oxide that can be alloyed with lithium) may be used. Among these, the battery active material is made of Si, Sn, Al, Sb, and In in that the discharge capacity and cycle characteristics of the lithium secondary battery obtained using the obtained composite active material for lithium secondary battery are more excellent. It is preferable to contain at least one element selected from the group, and it is more preferable to contain Si and Sn elements.
なお、該合金については、上記した金属の組み合わせからなる合金の他、リチウムイオンを吸蔵および放出しない金属を含む合金であってもよい。この場合、合金中の上記リチウムと合金化可能な金属の含有量はより多いほうが好ましい。ＳＥＭ観察で得られる２次電子像で判断する粒子の均一性やサイクル特性などから判断すると、金属含有量の上限は７０質量％であることが好ましく、６０質量％以下がより好ましい。 In addition, about this alloy, the alloy containing the metal which does not occlude and discharge | release lithium ion other than the alloy which consists of a combination of the above-mentioned metal may be sufficient. In this case, the content of the metal that can be alloyed with the lithium in the alloy is preferably larger. Judging from the uniformity of the particles and the cycle characteristics determined from the secondary electron image obtained by SEM observation, the upper limit of the metal content is preferably 70% by mass, and more preferably 60% by mass or less.
使用される電池活物質の形状は特に制限されず、粉状、板状、粒状、繊維状、塊状、球状など、あらゆる形状のものが使用可能である。 The shape of the battery active material to be used is not particularly limited, and any shape such as powder, plate, granule, fiber, lump, and sphere can be used.
使用される電池活物質の平均粒径（Ｄ５０）は、０．０１〜０．６μｍが好ましく、特に好ましくは０．０１〜０．３μｍである。なお、平均粒径（Ｄ５０）はレーザー回折法または動的光散乱法で測定した体積平均の粒子径である。 The average particle diameter (D50) of the battery active material used is preferably 0.01 to 0.6 μm, particularly preferably 0.01 to 0.3 μm. The average particle diameter (D50) is a volume average particle diameter measured by a laser diffraction method or a dynamic light scattering method.
また、Ｄ９０は０．０１〜１．０μｍが好ましく、特に好ましくは０．０１〜０．６μｍである。Ｄ９０はレーザー回折法又は動的光散乱法による測定された最少粒径値より累積値９０％にあたる粒子径である。 Further, D90 is preferably 0.01 to 1.0 μm, particularly preferably 0.01 to 0.6 μm. D90 is a particle diameter corresponding to a cumulative value of 90% from the minimum particle diameter value measured by the laser diffraction method or the dynamic light scattering method.
ＢＥＴ法で測定されるＢＥＴ比表面積は、４０〜３００ｍ２／ｇが好ましく、特に好ましくは７０〜３００ｍ２／ｇである。 The BET specific surface area measured by the BET method is preferably 40 to 300 m 2 / g, particularly preferably 70 to 300 m 2 / g.
なお、上記所定の平均粒子径の電池活物質を得る方法としては、攪拌槽型攪拌ミル（ビーズミル等）等などの公知の装置を用いて電池活物質の粉砕を行うことによって、上記した粒径の小さい粉末を得ることが可能である。
＜リチウム二次電池用複合活物質（以後、単に複合活物質とも称する）＞
リチウム二次電池用複合活物質には、上述した黒鉛成分、ハードカーボン、ソフトカーボン、および、電池活物質が含まれる。
In addition, as a method of obtaining the battery active material having the predetermined average particle diameter, the above-mentioned particle size is obtained by pulverizing the battery active material using a known apparatus such as a stirring tank type stirring mill (bead mill or the like). Small powder can be obtained.
<Composite active material for lithium secondary battery (hereinafter also simply referred to as composite active material)>
The composite active material for a lithium secondary battery includes the above-described graphite component, hard carbon, soft carbon, and battery active material.
複合活物質中における黒鉛成分の含有量は特に制限されないが、本発明の効果がより優れる点で、１５〜６５質量部が好ましく、２５〜５５質量部がより好ましく、３５〜５０質量部がさらに好ましい。 The content of the graphite component in the composite active material is not particularly limited, but is preferably 15 to 65 parts by mass, more preferably 25 to 55 parts by mass, and further preferably 35 to 50 parts by mass because the effects of the present invention are more excellent. preferable.
ハードカーボンの含有量は特に制限されないが、本発明の効果がより優れる点で、５〜４０質量部が好ましく、８〜３０質量部がより好ましい。 Although content in particular of hard carbon is not restrict | limited, 5-40 mass parts is preferable at the point which the effect of this invention is more excellent, and 8-30 mass parts is more preferable.
また、ソフトカーボンの含有量は、発明の効果がより優れる点で、５〜６０質量部が好ましく、１５〜５０質量部がより好ましく、２０〜４０質量部がさらに好ましい。 The soft carbon content is preferably 5 to 60 parts by mass, more preferably 15 to 50 parts by mass, and still more preferably 20 to 40 parts by mass, from the viewpoint that the effects of the invention are more excellent.
複合活物質中における電池活物質の含有量は特に制限されないが、本発明の効果がより優れる点で、５〜８０質量部が好ましく、１０〜７０質量部がより好ましく、１５〜５０質量％がさらに好ましい。 The content of the battery active material in the composite active material is not particularly limited, but is preferably 5 to 80 parts by mass, more preferably 10 to 70 parts by mass, and 15 to 50% by mass in terms of more excellent effects of the present invention. Further preferred.
複合活物質の形状は特に制限されないが、本発明の効果がより優れる点で、略球状の形状を有することが好ましい。なお、略球状とは、粉砕等により生成した粒子の角が取れているもの、球状もしくは回転楕円体形状、円板もしくは小判形状で厚みを有して角が丸いもの、またはそれらが変形したもので角が丸いものなどを含み、その円形度は０．７〜１．０である。なお、円形度は走査型電子顕微鏡で撮影した粒子像を画像解析して測定した。すなわち、粒子の投影面積（Ａ）と周囲長（ＰＭ）を写真から測定し、等しい周囲長（ＰＭ）を持つ真円の面積を（Ｂ）とした時に、円形度はＡ／Ｂで定義される。前記真円の半径をｒとした時、ＰＭ＝２πｒ、及びＢ＝πｒ２が成り立つので、これより円形度Ａ／Ｂ＝Ａ×４π／（ＰＭ）２で算出される。これにより任意の１００個以上の複合粒子の球形度を求め、その平均値を複合粒子の平均円形度とした。この際、短軸長さが１μｍ未満の扁平状微粒子を除いた略球状粒子の平均値を複合粒子の平均円形度とすることもできる。形状が丸みを帯びることにより複合粒子のかさ密度が高まり、負極にした時の充填密度が高まる。 The shape of the composite active material is not particularly limited, but preferably has a substantially spherical shape from the viewpoint that the effect of the present invention is more excellent. In addition, the substantially spherical shape means that particles produced by pulverization or the like have rounded corners, spherical or spheroid shapes, discs or oblong shapes with thick rounded corners, or those deformed And the roundness is 0.7 to 1.0. The circularity was measured by image analysis of a particle image taken with a scanning electron microscope. That is, when the projected area (A) and the perimeter (PM) of a particle are measured from a photograph and the area of a perfect circle having the same perimeter (PM) is (B), the circularity is defined as A / B. The When the radius of the true circle is r, PM = 2πr and B = πr 2 are established, and from this, the circularity A / B = A × 4π / (PM) 2 is calculated. Thus, the sphericity of any 100 or more composite particles was obtained, and the average value was defined as the average circularity of the composite particles. At this time, the average value of the substantially spherical particles excluding the flat fine particles having a minor axis length of less than 1 μm can be used as the average circularity of the composite particles. When the shape is rounded, the bulk density of the composite particles is increased, and the packing density when the negative electrode is formed is increased.
複合活物質の粒径（Ｄ５０：５０％体積粒径）は特に制限されないが、本発明の効果がより優れる点で、２〜４０μｍが好ましく、５〜３５μｍがより好ましく、５〜３０μｍがさらに好ましい。 The particle size (D50: 50% volume particle size) of the composite active material is not particularly limited, but is preferably 2 to 40 μm, more preferably 5 to 35 μm, and even more preferably 5 to 30 μm in terms of more excellent effects of the present invention. .
なお、粒径（Ｄ９０：９０％体積粒径）は特に制限されないが、本発明の効果がより優れる点で、１０〜７５μｍが好ましく、１０〜６０μｍがより好ましく、２０〜４５μｍがさらに好ましい。 The particle size (D90: 90% volume particle size) is not particularly limited, but is preferably 10 to 75 μm, more preferably 10 to 60 μm, and even more preferably 20 to 45 μm, in that the effect of the present invention is more excellent.
さらに、粒径（Ｄ１０：１０％体積粒径）は特に制限されないが、本発明の効果がより優れる点で、１〜２０μｍが好ましく、２〜１０μｍがより好ましい。 Further, the particle size (D10: 10% volume particle size) is not particularly limited, but 1 to 20 μm is preferable and 2 to 10 μm is more preferable in that the effect of the present invention is more excellent.
Ｄ１０、Ｄ５０およびＤ９０は、レーザー回折散乱法により測定した累積粒度分布の微粒側から累積１０％、累積５０％、累積９０％の粒径にそれぞれ該当する。 D10, D50 and D90 correspond to the particle sizes of 10%, 50% and 90% from the fine particle side of the cumulative particle size distribution measured by the laser diffraction scattering method, respectively.
なお、測定に際しては、複合活物質を液体に加えて超音波などを利用しながら激しく混合し、作製した分散液を装置にサンプルとして導入し、測定を行う。液体としては作業上、水やアルコール、低揮発性の有機溶媒を用いることが好ましい。この時、得られる粒度分布図は正規分布を示すことが好ましい。 In the measurement, the composite active material is added to the liquid and mixed vigorously while utilizing ultrasonic waves, and the prepared dispersion is introduced as a sample into the apparatus for measurement. As the liquid, it is preferable to use water, alcohol, or a low-volatile organic solvent for work. At this time, the obtained particle size distribution diagram preferably shows a normal distribution.
複合活物質の比表面積（ＢＥＴ比表面積）は特に制限されないが、本発明の効果がより優れる点で、３０ｍ２／ｇ以下が好ましく、１０ｍ２／ｇ以下がより好ましい。下限は特に制限されないが、０．１ｍ２／ｇ以上が好ましい。 The specific surface area of the composite active material (BET specific surface area) is not particularly limited, in terms of the effect of the present invention is more excellent, preferably 30 m 2 / g or less, 10 m 2 / g or less is more preferable. Although a minimum in particular is not restrict | limited, 0.1 m < 2 > / g or more is preferable.
複合活物質の比表面積（ＢＥＴ比表面積）の測定方法は、試料を３００℃で３０分真空乾燥後、窒素吸着１点法で測定する。 The measurement method of the specific surface area (BET specific surface area) of the composite active material is measured by a nitrogen adsorption one-point method after vacuum drying the sample at 300 ° C. for 30 minutes.
本発明のリチウムイオン二次電池用複合活物質においては、電池活物質が０．２μｍ以下の厚みの黒鉛薄層の間に挟まった構造であり、その構造が積層および／または網目状に広がっており、黒鉛薄層が活物質粒子の表面付近で湾曲して活物質粒子を覆っていることが好ましい。 In the composite active material for a lithium ion secondary battery of the present invention, the battery active material is sandwiched between thin graphite layers having a thickness of 0.2 μm or less, and the structure spreads in a laminated and / or network form. The graphite thin layer is preferably curved near the surface of the active material particles to cover the active material particles.
厚みが０．２μｍを超えると黒鉛薄層の電子伝達効果が薄まる。黒鉛薄層を断面で見て線状の場合、その長さは負極活物質粒子のサイズの半分以上あることが電子伝達に好ましく、活物質粒子のサイズと同等程度であることがさらに好ましい。黒鉛薄層が網目状の場合、黒鉛薄層の網が活物質粒子のサイズの半分以上に渡って繋がっていることが電子伝達に好ましく、活物質粒子のサイズと同等程度であることがさらに好ましい。 When the thickness exceeds 0.2 μm, the electron transfer effect of the graphite thin layer is reduced. When the graphite thin layer is linear when viewed in cross section, its length is preferably at least half the size of the negative electrode active material particles for electron transfer, and more preferably about the same as the size of the active material particles. When the graphite thin layer is network-like, it is preferable for electron transfer that the network of the graphite thin layer is connected to more than half of the size of the active material particles, and more preferably about the same size as the size of the active material particles. .
本発明においては、黒鉛薄層が活物質粒子の表面付近で湾曲して活物質粒子を覆うことが好ましい。そのような形状にすることで、黒鉛薄層端面から電解液が侵入して、電池活物質や黒鉛薄層端面と電解液が直接接して、充放電時に反応物が形成され、効率が下がるというリスクが低減する。 In the present invention, the graphite thin layer is preferably curved near the surface of the active material particles to cover the active material particles. By adopting such a shape, the electrolyte enters from the end face of the graphite thin layer, the battery active material or the end face of the graphite thin layer is in direct contact with the electrolyte, and a reaction product is formed during charge and discharge, which reduces efficiency. Risk is reduced.
また、本発明では、複合活物質がソフトカーボンを含有することにより、黒鉛成分及び電池活物質がソフトカーボンで覆われている構造を有する。該構造を有することにより、充放電を繰り返した後でも体積膨張が抑制された電極材料の作製が可能で、かつ、優れたサイクル特性を示すリチウム二次電池の作製が可能なリチウム二次電池用複合活物質が得られるものである。
＜アクリル酸系重合体＞
次にリチウム二次電池用負極材におけるバインダーとして用いるアクリル酸系重合体について詳述する。
In the present invention, the composite active material contains soft carbon, so that the graphite component and the battery active material are covered with soft carbon. By having this structure, it is possible to produce an electrode material in which volume expansion is suppressed even after repeated charge and discharge, and it is possible to produce a lithium secondary battery exhibiting excellent cycle characteristics. A composite active material is obtained.
<Acrylic acid polymer>
Next, the acrylic acid polymer used as a binder in the negative electrode material for a lithium secondary battery will be described in detail.
アクリル酸系重合体とは、アクリル酸単独重合体及びアクリル酸と他のモノマーとの共重合体をいう。ここで、アクリル酸と共重合可能な他のモノマーとしては、アクリル酸以外のエチレン性不飽和カルボン酸、（メタ）アクリル酸アルキルエステル化合物、芳香族ビニル化合物、ポリオキシアルキレン基含有ビニル化合物、アルコキシル基含有ビニル化合物、シアノ基含有ビニル化合物、シアン化ビニル化合物、ビニルエーテル化合物、ビニルエステル化合物、共役ジエン等が挙げられる。 An acrylic acid polymer refers to an acrylic acid homopolymer and a copolymer of acrylic acid and another monomer. Here, as other monomers copolymerizable with acrylic acid, ethylenically unsaturated carboxylic acid other than acrylic acid, (meth) acrylic acid alkyl ester compound, aromatic vinyl compound, polyoxyalkylene group-containing vinyl compound, alkoxyl Examples thereof include a group-containing vinyl compound, a cyano group-containing vinyl compound, a vinyl cyanide compound, a vinyl ether compound, a vinyl ester compound, and a conjugated diene.
アクリル酸系重合体の合成方法としては、例えばアクリル酸又はアクリル酸と共重合可能な他のモノマーを、ラジカル重合開始剤下、適当な溶媒中に溶解又は分散させ、温度５０〜１００℃で重合することにより得ることができる。用いるラジカル重合開始剤としては、過硫酸カリウム等の過硫酸塩系開始剤、アゾビスイソブチロニトリル等のアゾ系開始剤、過酸化ベンゾイル等の過酸化物系開始剤等を挙げることができる。 As a method for synthesizing an acrylic acid polymer, for example, acrylic acid or another monomer copolymerizable with acrylic acid is dissolved or dispersed in a suitable solvent under a radical polymerization initiator and polymerized at a temperature of 50 to 100 ° C. Can be obtained. Examples of the radical polymerization initiator used include persulfate initiators such as potassium persulfate, azo initiators such as azobisisobutyronitrile, peroxide initiators such as benzoyl peroxide, and the like. .
用いる溶媒としては、水又は水と水溶性有機溶媒との混合溶媒が挙げられ、好ましくは水である。水としては、特に制限はなく、水道水、イオン交換水、蒸留水、純水（イオン交換後、蒸留）のいずれでもよいが、無機イオンが取り除かれているという観点で、イオン交換水か、純水がより好ましい。水溶性有機溶媒としては、例えば、メタノール、エタノール、１−プロパノール、２−プロパノール（イソプロパノール）、１−ブタノール、２−ブタノール、ｔ−ブタノール等の低級アルコール類；ジメチルホルムアミド等のアミド類；アセトン等のケトン類；１、４−ジオキサン等のエーテル類等が挙げられ、これらの中から１種類または２種類以上適宜選んで使用できる。 Examples of the solvent to be used include water or a mixed solvent of water and a water-soluble organic solvent, preferably water. The water is not particularly limited and may be tap water, ion exchange water, distilled water, or pure water (distilled after ion exchange), but from the viewpoint of removing inorganic ions, Pure water is more preferable. Examples of the water-soluble organic solvent include lower alcohols such as methanol, ethanol, 1-propanol, 2-propanol (isopropanol), 1-butanol, 2-butanol and t-butanol; amides such as dimethylformamide; acetone and the like Ketones; ethers such as 1,4-dioxane and the like can be used, and one or more of these can be appropriately selected and used.
アクリル酸系重合体の重量平均分子量（Ｍｗ）は、１００，０００〜３，０００，０００であることが好ましく、特に好ましくは２００，０００〜２，０００，０００である。 The weight average molecular weight (Mw) of the acrylic acid polymer is preferably 100,000 to 3,000,000, particularly preferably 200,000 to 2,000,000.
また、アクリル酸系重合体は、好ましくは中和率１０〜１００％、特に好ましくは３０〜１００％である。ここで、中和率とは、アクリル酸系重合体のカルボキシル基を中和剤により部分的に中和した割合である。ここで用いる中和剤としては、水酸化ナトリウム、水酸化カリウム、水酸化リチウム等の強アルカリ性の中和剤が好ましく、特に水酸化ナトリウム、水酸化リチウムが好ましい。
＜リチウム二次電池用負極材＞
本発明のリチウム二次電池用負極材は、リチウム二次電池用複合活物質とアクリル酸系重合体を含むリチウム二次電池用負極材である。
The acrylic acid polymer preferably has a neutralization rate of 10 to 100%, particularly preferably 30 to 100%. Here, the neutralization rate is a ratio obtained by partially neutralizing the carboxyl group of the acrylic acid polymer with a neutralizing agent. As the neutralizing agent used here, strong alkaline neutralizing agents such as sodium hydroxide, potassium hydroxide and lithium hydroxide are preferable, and sodium hydroxide and lithium hydroxide are particularly preferable.
<Anode material for lithium secondary battery>
The negative electrode material for lithium secondary batteries of the present invention is a negative electrode material for lithium secondary batteries containing a composite active material for lithium secondary batteries and an acrylic acid polymer.
リチウム二次電池用負極材におけるリチウム二次電池用複合活物質とアクリル酸系重合体の割合は、リチウム二次電池用複合活物質１００質量部に対して、アクリル酸系重合体１〜５０質量部が好ましく、特に好ましくは２〜４０質量部である。 The ratio of the lithium secondary battery composite active material to the acrylic acid polymer in the negative electrode material for the lithium secondary battery is 1 to 50 masses of the acrylic polymer with respect to 100 parts by mass of the lithium secondary battery composite active material. Part is preferred, particularly preferably 2 to 40 parts by weight.
リチウム二次電池用負極材には、導電性カーボンブラック、カーボンナノチューブまたはその混合物を含有することが好ましい。カーボンブラック、カーボンナノチューブまたはその混合物の配合量は特に制限されないが、リチウム二次電池用複合活物質１００質量部に対して、０．２〜４質量部であることが好ましく、０．５〜２質量部であることがより好ましい。カーボンナノチューブの例としては、シングルウォールカーボンナノチューブ、マルチウォールカーボンナノチューブが挙げられる。
＜リチウム二次電池用負極材の製造方法＞
最初に、リチウム二次電池用負極材におけるリチウム二次電池用複合活物質の製造方法について、詳述する。
The negative electrode material for a lithium secondary battery preferably contains conductive carbon black, carbon nanotubes or a mixture thereof. The blending amount of carbon black, carbon nanotube, or a mixture thereof is not particularly limited, but is preferably 0.2 to 4 parts by mass with respect to 100 parts by mass of the composite active material for a lithium secondary battery, 0.5 to 2 More preferably, it is part by mass. Examples of carbon nanotubes include single wall carbon nanotubes and multi-wall carbon nanotubes.
<Method for producing negative electrode material for lithium secondary battery>
Initially, the manufacturing method of the composite active material for lithium secondary batteries in the negative electrode material for lithium secondary batteries is explained in full detail.
リチウム二次電池用複合活物質の製造方法は特に制限されないが、製造工程が簡便であり、かつ、本発明の効果がより優れる点で、以下の第１実施態様〜第３実施態様の方法が挙げられる。 Although the manufacturing method of the composite active material for lithium secondary batteries is not particularly limited, the following first to third embodiments are preferable because the manufacturing process is simple and the effects of the present invention are more excellent. Can be mentioned.
以下、各実施態様について詳述する。
（第１実施態様）
複合活物質の製造方法の第１実施態様としては、所定の成分を含む第１混合物に球形化処理を施す球形化工程と、得られた第１混合物に対して加熱処理を施す第１加熱工程と、第１加熱工程で得られた焼成物とソフトカーボンの前駆体とを混合して第２混合物を得る混合工程と、第２混合物に対して加熱処理を施す第２加熱工程と、を有する方法が挙げられる。
Hereinafter, each embodiment will be described in detail.
(First embodiment)
As a 1st embodiment of the manufacturing method of a composite active material, the 1st heating process which heat-processes with respect to the spheroidizing process which performs the spheroidizing process to the 1st mixture containing a predetermined component, and the obtained 1st mixture And a mixing step of mixing the fired product obtained in the first heating step and a soft carbon precursor to obtain a second mixture, and a second heating step of performing a heat treatment on the second mixture. A method is mentioned.
以下、各工程の手順について詳述する。
［球形化工程］
球形化工程は、黒鉛成分、および、リチウムイオンと化合可能な電池活物質を含む第１混合物に球形化処理を施す工程である。
Hereafter, the procedure of each process is explained in full detail.
[Spheronization process]
The spheronization step is a step of spheronizing a first mixture containing a graphite component and a battery active material that can be combined with lithium ions.
使用される黒鉛成分および電池活物質の定義は、上述の通りである。 The definitions of the graphite component and the battery active material used are as described above.
なお、上記黒鉛成分としては、膨張黒鉛を使用することもできる。つまり、膨張黒鉛、および、電池活物質を含む第１混合物に球形化処理を施してもよい。 In addition, expanded graphite can also be used as the graphite component. That is, the first mixture containing expanded graphite and the battery active material may be spheroidized.
膨張黒鉛としては、市販品を使用してもよいし、公知の方法で製造してもよい。 As the expanded graphite, a commercially available product may be used, or it may be produced by a known method.
膨張黒鉛の製造方法としては、例えば、酸中に黒鉛（例えば、鱗片状黒鉛）を室温で浸漬した後、得られた酸処理黒鉛に加熱処理（好ましくは、７００〜１０００℃で処理）を施すことにより製造することができる。より具体的には、硫酸９質量部と硝酸１質量部の混酸に鱗片状天然黒鉛を１時間程度浸漬後、酸を除去し、水洗・乾燥を行う。その後、得られた酸処理黒鉛を８５０℃程度の炉に投入することで、黒鉛の層間に入った酸がガスとして噴出し、層間が部分的に広がり、広がったひだ状、或いはアコーディオンのような形状の膨張黒鉛が得られる。なお、酸処理黒鉛の代わりに、アルカリ金属など黒鉛と層間化合物を形成した黒鉛を使用しても、膨張黒鉛を得ることができる。 As a method for producing expanded graphite, for example, after immersing graphite (for example, flaky graphite) in acid at room temperature, the obtained acid-treated graphite is subjected to heat treatment (preferably treated at 700 to 1000 ° C.). Can be manufactured. More specifically, after scaly natural graphite is immersed in a mixed acid of 9 parts by mass of sulfuric acid and 1 part by mass of nitric acid for about 1 hour, the acid is removed, washed with water and dried. After that, the obtained acid-treated graphite is put into a furnace at about 850 ° C., so that the acid entering the graphite layer is ejected as a gas, and the interlayer is partially expanded and spread like a fold or accordion. Shaped expanded graphite is obtained. Note that expanded graphite can also be obtained by using graphite formed with an interlayer compound such as alkali metal instead of acid-treated graphite.
なお、膨張黒鉛中には、黒鉛面を重ねる方向でグラフェンシートが複数枚重なった層（薄片化黒鉛）が含まれており、グラフェンシートは主にファンデルワールス力によって互いに結合している。 Note that the expanded graphite includes a layer (flaky graphite) in which a plurality of graphene sheets are stacked in the direction in which the graphite surfaces overlap, and the graphene sheets are bonded to each other mainly by van der Waals force.
上記で得られた酸処理黒鉛の嵩密度は特に限定されないが、酸処理黒鉛が十分に膨張する点で、０．６ｇ／ｃｍ３以上が好ましく、０．７ｇ／ｃｍ３以上がより好ましい。上限は特に制限されないが、製造上の問題から、１．０ｇ／ｃｍ３以下の場合が多い。 Although the bulk density of the acid-treated graphite obtained above is not particularly limited, 0.6 g / cm 3 or more is preferable and 0.7 g / cm 3 or more is more preferable in view of sufficient expansion of the acid-treated graphite. The upper limit is not particularly limited, but is often 1.0 g / cm 3 or less due to manufacturing problems.
なお、嵩密度の測定方法としては、１００ｍｌのガラス製メスシリンダーに試料を圧縮しないように挿入し、その試料質量を試料体積で除して求める。 In addition, as a measuring method of bulk density, it inserts so that a sample may not be compressed in a 100 ml glass graduated cylinder, and it calculates | requires by dividing the sample mass by a sample volume.
使用される膨張黒鉛の嵩比重は特に制限されないが、本発明の効果がより優れる点で、０．０５ｇ／ｃｍ３以下が好ましく、０．０１ｇ／ｃｍ３以下がより好ましい。下限は特に限定されないが、製造上の問題から、０．００１ｇ／ｃｍ３以上の場合が多い。 While bulk density of the expanded graphite to be used is not particularly limited, in terms of the effect of the present invention is more excellent, preferably 0.05 g / cm 3 or less, 0.01 g / cm 3 or less is more preferable. The lower limit is not particularly limited, but is often 0.001 g / cm 3 or more due to manufacturing problems.
なお、嵩比重の測定方法としては、５００ｍｌのガラス製メスシリンダーに試料を圧縮しないように挿入し、その試料質量を試料体積で除して求める。 In addition, as a measuring method of bulk specific gravity, it inserts so that a sample may not be compressed into a 500 ml glass graduated cylinder, and it calculates | requires by dividing the sample mass by a sample volume.
膨張黒鉛の比表面積は特に制限されないが、本発明の効果がより優れる点で、比表面積が１０ｍ２／ｇ以上が好ましく、２０ｍ２／ｇ以上がより好ましい。上限は特に制限されないが、製造の手順が煩雑となり、合成が困難な点で、比表面積は２００ｍ２／ｇ以下が好ましい。 The specific surface area of the expanded graphite is not particularly limited, but the specific surface area is preferably 10 m 2 / g or more, more preferably 20 m 2 / g or more, from the viewpoint that the effect of the present invention is more excellent. The upper limit is not particularly limited, but the specific surface area is preferably 200 m 2 / g or less in that the production procedure is complicated and the synthesis is difficult.
なお、膨張黒鉛の比表面積は、窒素吸着によるＢＥＴ法（ＪＩＳ Ｚ ８８３０、一点法）を用いて測定したものである。 In addition, the specific surface area of expanded graphite is measured using the BET method (JIS Z 8830, one point method) by nitrogen adsorption.
黒鉛成分および電池活物質を含む第１混合物を得る方法は特に制限されず、公知の方法を採用することができ、いわゆる乾式処理または湿式処理などが挙げられる。なお、得られる第１混合物中での各成分がより均一に混合する点より、湿式処理の態様が好ましい。 A method for obtaining the first mixture containing the graphite component and the battery active material is not particularly limited, and a known method can be adopted, and examples thereof include so-called dry processing or wet processing. In addition, the aspect of a wet process is preferable from the point which each component in the obtained 1st mixture mixes more uniformly.
乾式処理としては、例えば、公知の攪拌機（例えば、ヘンシェルミキサー）に黒鉛成分および電池活物質を加え、混合する方法がある。 As the dry process, for example, a graphite component and a battery active material are added to a known stirrer (for example, a Henschel mixer) and mixed.
湿式処理としては、例えば、黒鉛成分と電池活物質とを溶媒中に分散させ、得られた溶液を混合攪拌して、溶媒を除去する方法が挙げられる。 Examples of the wet treatment include a method of dispersing a graphite component and a battery active material in a solvent, mixing and stirring the obtained solution, and removing the solvent.
湿式処理の際に使用される溶媒は特に制限されず、黒鉛成分と電池活物質とを分散させることができる溶媒であればよい。例えば、アルコール系溶媒（例えば、メタノール、エタノール、イソプロパノール）、ケトン系溶媒（例えば、アセトン、メチルエチルケトン、シクロヘキサノン）、アミド系溶媒（例えば、ホルムアミド、ジメチルアセトアミド、Ｎ−メチルピロリドン、Ｎ−エチルピロリドン）、ニトリル系溶媒（例えば、アセトニトリル、プロピオニトリル）、エステル系溶媒（例えば、酢酸メチル、酢酸エチル）、カーボネート系溶媒（例えば、ジメチルカーボネート、ジエチルカーボネート）、エーテル系溶媒（例えば、セロソルブ）、ハロゲン系溶媒、水およびこれらの混合物などが挙げられる。 The solvent used in the wet treatment is not particularly limited as long as it can disperse the graphite component and the battery active material. For example, alcohol solvents (eg, methanol, ethanol, isopropanol), ketone solvents (eg, acetone, methyl ethyl ketone, cyclohexanone), amide solvents (eg, formamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone), Nitrile solvents (eg acetonitrile, propionitrile), ester solvents (eg methyl acetate, ethyl acetate), carbonate solvents (eg dimethyl carbonate, diethyl carbonate), ether solvents (eg cellosolve), halogens Examples thereof include a solvent, water, and a mixture thereof.
なかでも、得られるリチウム二次電池用複合活物質を用いたリチウム二次電池のサイクル特性がより優れる点で、アルコール系溶媒が好ましい。 Among these, an alcohol-based solvent is preferable in that the cycle characteristics of the lithium secondary battery using the obtained composite active material for a lithium secondary battery are more excellent.
湿式処理において、黒鉛成分と電池活物質とを混合攪拌する条件は特に制限されず、使用される材料に応じて適宜最適な条件が選択される。 In the wet processing, the conditions for mixing and stirring the graphite component and the battery active material are not particularly limited, and optimal conditions are appropriately selected according to the materials used.
また、必要に応じて、攪拌処理時に超音波処理を実施してもよい。つまり、黒鉛成分と電池活物質とを超音波処理を施しながら混合して第１混合物を製造してもよい。言い換えると、第１混合物としては、黒鉛成分および電池活物質を含む組成物に対して超音波処理を施して得られる混合物であってもよい。 Moreover, you may implement an ultrasonic treatment at the time of a stirring process as needed. That is, the first mixture may be manufactured by mixing the graphite component and the battery active material while performing ultrasonic treatment. In other words, the first mixture may be a mixture obtained by subjecting a composition containing a graphite component and a battery active material to ultrasonic treatment.
溶媒を除去する方法は特に制限されず、公知の装置（例えば、エバポレータ）などを使用する方法が挙げられる。 The method for removing the solvent is not particularly limited, and examples thereof include a method using a known apparatus (for example, an evaporator).
黒鉛成分と電池活物質との混合比は特に制限されないが、本発明の効果がより優れる点で、黒鉛成分１００質量部に対して、電池活物質を２５〜１５０質量部混合することが好ましく、５０〜１００質量部混合することがより好ましい。 The mixing ratio of the graphite component and the battery active material is not particularly limited, but it is preferable that the battery active material is mixed in an amount of 25 to 150 parts by mass with respect to 100 parts by mass of the graphite component in terms of more excellent effects of the present invention. It is more preferable to mix 50-100 mass parts.
なお、第１混合物には、黒鉛成分および電池活物質以外の成分が含まれていてもよく、例えば、上述したハードカーボンの前駆体として使用される高分子化合物が挙げられる。 In addition, components other than a graphite component and a battery active material may be contained in the 1st mixture, For example, the high molecular compound used as a precursor of the hard carbon mentioned above is mentioned.
黒鉛成分とハードカーボンの前駆体との混合比率は特に制限されないが、本発明の効果がより優れる点で、黒鉛成分１００質量部に対して、ハードカーボンの前駆体が１〜５０質量部であることが好ましく、１０〜３０質量部であることがより好ましい。 The mixing ratio of the graphite component and the hard carbon precursor is not particularly limited, but the hard carbon precursor is 1 to 50 parts by mass with respect to 100 parts by mass of the graphite component in that the effect of the present invention is more excellent. It is preferably 10 to 30 parts by mass.
なお、後述する球形化処理の前に、必要に応じて、得られた第１混合物をプレスするプレス工程が含まれていてもよい。プレス工程を実施すると、黒鉛層間の距離がより小さくなり、後述する球形化処理がより効率的に進行する。 In addition, before the spheronization process mentioned later, the press process of pressing the obtained 1st mixture may be included as needed. If a press process is implemented, the distance between graphite layers will become smaller and the spheroidization process mentioned later advances more efficiently.
なお、プレスの方法は特に制限されず、公知の方法を採用できる。 The pressing method is not particularly limited, and a known method can be adopted.
球形化処理の方法は特に制限されず、主に衝撃応力を加えられる粉砕機であれば特に限定されない。粉砕機としては、例えば、高速回転衝撃式粉砕機が挙げられ、より具体的にはサンプルミル、ハンマミル、ピンミル等を用いることができる。なかでも、本発明の効果がより優れる点で、ピンミルが好ましい。 The method of spheroidizing treatment is not particularly limited as long as it is a pulverizer capable of mainly applying impact stress. Examples of the pulverizer include a high-speed rotational impact pulverizer. More specifically, a sample mill, a hammer mill, a pin mill, or the like can be used. Especially, a pin mill is preferable at the point which the effect of this invention is more excellent.
高速回転衝撃式粉砕機としては、高速回転するローターに試料を衝突させて、その衝撃力による微細化を達成するものが挙げられ、例えば、ローターに固定式またはスイング式の衝撃子を取り付けたハンマーミルタイプのハンマー型、回転する円盤にピンや衝撃ヘッドを取り付けたピンミルタイプの回転円盤型、試料がシャフト方向に搬送されながら粉砕する軸流型、狭い環状部での粒子の微細化を行うアニュラー型等が挙げられる。より具体的には、ハンマミル、ピンミル、スクリーンミル、ターボ型ミル、遠心分級型ミルなどが挙げられる。 Examples of high-speed rotary impact type pulverizers include those that collide a sample with a rotor that rotates at high speed and achieve miniaturization by the impact force. For example, a hammer with a fixed or swing type impactor attached to the rotor Mill type hammer type, pin mill type rotary disc type with a pin and impact head attached to a rotating disc, an axial flow type that crushes while the sample is conveyed in the shaft direction, and an annular type that refines particles in a narrow annular part Examples include molds. More specifically, a hammer mill, a pin mill, a screen mill, a turbo mill, a centrifugal classification mill, and the like can be given.
なお、本工程を上記高速回転衝撃式粉砕機で行なう場合には、通常１００ｒｐｍ以上、好ましくは１５００ｒｐｍ以上、また、通常３００００ｒｐｍ以下の回転速度で球形化を行うことが好ましい。過度の衝撃力により球形化より粉砕が進行する。したがって衝突速度は２０ｍ／秒〜１００ｍ／秒程度とすることが好ましい。 In addition, when performing this process with the said high-speed rotation impact type | formula grinder, it is preferable to spheroidize normally at a rotational speed of 100 rpm or more, preferably 1500 rpm or more, and usually 30000 rpm or less. Grinding progresses from spheroidization due to excessive impact force. Therefore, the collision speed is preferably about 20 m / second to 100 m / second.
粉砕と異なり、球形化処理は低い衝撃力で処理するため、本工程は通常循環処理を行うことが好ましい。その処理時間は、使用する粉砕機の種類や仕込み量等によって異なるが、通常２分以内であり、適切なピン或いは衝突板の配置がなされた装置であれば処理時間は１０秒程度で終了する。 Unlike pulverization, since the spheronization treatment is carried out with a low impact force, it is usually preferable to perform a circulation treatment in this step. The processing time varies depending on the type of the pulverizer to be used, the amount charged, and the like, but is usually within 2 minutes, and the processing time can be completed in about 10 seconds if the apparatus is provided with an appropriate pin or collision plate. .
また、球形化処理は空気中で行うことが好ましい。さらに、上記処理は、複数回実施してもよい。
［第１加熱工程（第１焼成工程）］
第１加熱工程は、上記球形化工程にて得られた第１混合物（球形化処理が施された第１混合物）に対して加熱処理を施す工程である。
The spheronization treatment is preferably performed in air. Further, the above process may be performed a plurality of times.
[First heating step (first firing step)]
A 1st heating process is a process of heat-processing with respect to the 1st mixture (1st mixture in which the spheronization process was performed) obtained at the said spheronization process.
加熱処理（焼成処理）の条件としては、本発明の効果がより優れる点で、加熱温度としては４００℃以上が好ましく、６００℃以上がより好ましく、７００℃以上がさらに好ましい。なお、上限は特に制限されないが、耐熱性の点から、２０００℃以下が好ましく、１５００℃以下がより好ましく、１０００℃以下がさらに好ましい。 As the conditions for the heat treatment (baking treatment), the heating temperature is preferably 400 ° C. or higher, more preferably 600 ° C. or higher, and even more preferably 700 ° C. or higher in that the effect of the present invention is more excellent. The upper limit is not particularly limited, but is preferably 2000 ° C. or less, more preferably 1500 ° C. or less, and further preferably 1000 ° C. or less from the viewpoint of heat resistance.
また、加熱時間としては、０．５時間以上が好ましく、１時間以上がより好ましい。なお、上限は特に制限されないが、発明の効果が飽和する点から、５時間以下の場合が多い。 Moreover, as heating time, 0.5 hour or more is preferable and 1 hour or more is more preferable. The upper limit is not particularly limited, but is often 5 hours or less from the point where the effects of the invention are saturated.
加熱処理を行う雰囲気は、炭素の酸化を防ぐ観点から、不活性雰囲気下が好ましい。 The atmosphere for the heat treatment is preferably an inert atmosphere from the viewpoint of preventing the oxidation of carbon.
なお、上記加熱工程の後、必要に応じて、得られた複合活物質をより微細化するための粉砕処理を実施してもよい。粉砕方法としては、公知の手段が実施できる。
［混合工程］
混合工程は、上記第１加熱工程で得られた焼成物とソフトカーボンの前駆体とを混合して第２混合物を得る工程である。本工程で得られる第２混合物中では、黒鉛成分および電池活物質を含む焼成物（複合粒子）の表面に、ソフトカーボンの前駆体が付着している。そのため、後述する第２加熱工程を実施すると、焼成物表面のソフトカーボンの前駆体が焼成され、ソフトカーボンで覆われた複合粒子、つまり、複合活物質が得られる。
In addition, you may implement the grinding | pulverization process for refinement | miniaturizing the obtained composite active material further as needed after the said heating process. As the pulverization method, known means can be implemented.
[Mixing process]
The mixing step is a step of obtaining the second mixture by mixing the fired product obtained in the first heating step and the soft carbon precursor. In the second mixture obtained in this step, a soft carbon precursor is attached to the surface of the fired product (composite particles) containing the graphite component and the battery active material. Therefore, when the 2nd heating process mentioned later is implemented, the precursor of the soft carbon on the surface of a baked material will be baked, and the composite particle covered with soft carbon, ie, a composite active material, will be obtained.
混合方法は特に制限されず、公知の方法を採用することができ、上記球形化処理にて述べた乾式処理または湿式処理などが挙げられる。 The mixing method is not particularly limited, and a known method can be adopted, and examples thereof include the dry processing or wet processing described in the spheronization process.
第２混合物とソフトカーボンの前駆体との混合比は特に制限されないが、本発明の効果がより優れる点で、第２混合物１００質量部に対して、ソフトカーボンの前駆体を０．１〜７０質量部混合することが好ましく、１５〜５０質量部混合することがより好ましい。
［第２加熱工程（第２焼成工程）］
第２加熱工程は、上記混合工程で得られた第２混合物に対して加熱処理を施す工程である。加熱処理の条件は、加熱温度４００℃以上、昇温速度を１℃／ｍｉｎ以上にすることが好ましく、３℃／ｍｉｎ以上とすることが特に好ましい。加熱温度が４００℃未満であると、ソフトカーボンの形成が不十分となり電池評価の特性が悪くなる。一方、加熱温度が１２００℃以上では、添加金属元素と黒鉛元素の反応が起き易く、同様に電池評価の特性が悪くなる。また、昇温速度が１℃／ｍｉｎ未満では、複合活物質の比表面積が大きくなり、電解液が浸漬し易く、電池評価の特性が低下する。
The mixing ratio of the second mixture and the soft carbon precursor is not particularly limited, but the soft carbon precursor is added in an amount of 0.1 to 70 with respect to 100 parts by mass of the second mixture in that the effect of the present invention is more excellent. It is preferable to mix by mass part, and it is more preferable to mix 15-50 mass parts.
[Second heating step (second baking step)]
A 2nd heating process is a process of heat-processing with respect to the 2nd mixture obtained at the said mixing process. The heat treatment conditions are preferably a heating temperature of 400 ° C. or higher and a temperature increase rate of 1 ° C./min or higher, particularly preferably 3 ° C./min or higher. If the heating temperature is less than 400 ° C., the formation of soft carbon becomes insufficient and the battery evaluation characteristics deteriorate. On the other hand, when the heating temperature is 1200 ° C. or higher, the reaction between the additive metal element and the graphite element easily occurs, and the battery evaluation characteristics are similarly deteriorated. On the other hand, when the rate of temperature increase is less than 1 ° C./min, the specific surface area of the composite active material is increased, the electrolyte is easily immersed, and the battery evaluation characteristics are deteriorated.
上記焼成で得られた複合活物質（第２混合物）は、さらに解砕、分級することができる。解砕、分級方法は特に限定しないが、解砕時に第１混合物を壊さない程度の解砕が必要であり、解砕力が弱いボールミルなどの方法が好ましい。また長時間の粉砕は、小粒径の分布が増え、電池評価の特性が低下する。
（第２実施形態）
複合活物質の製造方法の第２実施態様としては、所定の成分を含む第１混合物に球形化処理を施す球形化工程と、球形化処理が施された第１混合物とソフトカーボンの前駆体とを混合して第３混合物を得る混合工程と、得られた第３混合物に対して加熱処理を施す加熱工程と、を有する方法が挙げられる。
The composite active material (second mixture) obtained by the firing can be further crushed and classified. The crushing and classification methods are not particularly limited, but crushing to the extent that the first mixture is not broken at the time of crushing is necessary, and a method such as a ball mill having a weak crushing force is preferable. Further, long-time pulverization increases the distribution of small particle diameters and degrades battery evaluation characteristics.
(Second Embodiment)
As a second embodiment of the method for producing a composite active material, a spheronization process for subjecting a first mixture containing a predetermined component to a spheronization process, a first mixture subjected to the spheronization process, and a soft carbon precursor, The method which has a mixing process which mixes and obtains the 3rd mixture, and a heating process which heat-processes with respect to the obtained 3rd mixture is mentioned.
以下、各工程の手順について詳述する。
［球形化工程］
球形化工程は、黒鉛成分、および、リチウムイオンと化合可能な電池活物質を含む第１混合物に球形化処理を施す工程である。
Hereafter, the procedure of each process is explained in full detail.
[Spheronization process]
The spheronization step is a step of spheronizing a first mixture containing a graphite component and a battery active material that can be combined with lithium ions.
本工程は、上述した第１の実施形態の球形化工程と同じ工程であるため、説明を省略する。
［混合工程］
混合工程は、上記球形化処理が施された第１混合物とソフトカーボンの前駆体とを混合して第３混合物を得る工程である。
Since this step is the same as the spheronization step of the first embodiment described above, description thereof is omitted.
[Mixing process]
The mixing step is a step of obtaining a third mixture by mixing the spheroidized first mixture and the soft carbon precursor.
使用されるソフトカーボンの前駆体の定義は、上述の通りである。 The definition of the soft carbon precursor used is as described above.
第３混合物を得るための混合方法は特に制限されず、公知の方法を採用することができ、上記第１の実施形態の球形化処理にて述べた乾式処理または湿式処理などが挙げられる。
［加熱工程］
加熱工程は、上記混合工程で得られた第３混合物に対して加熱処理を施す工程である。加熱処理の条件は、加熱温度４００℃以上、昇温速度を１℃／ｍｉｎ以上とすることが好ましく、特に３℃／ｍｉｎ以上とすることが好ましい。加熱温度が４００℃未満であると、ソフトカーボンの形成が不十分となり電池評価の特性が悪くなる。一方、加熱温度が１２００℃以上では、添加金属元素と黒鉛元素の反応が起き易く、同様に電池評価の特性が悪くなる。また、昇温速度が１℃／ｍｉｎ未満では、複合活物質の比表面積が大きくなり、電解液が浸漬し易く、電池評価の特性が低下する。
The mixing method for obtaining the third mixture is not particularly limited, and a known method can be adopted, and examples thereof include the dry process or the wet process described in the spheronization process of the first embodiment.
[Heating process]
A heating process is a process which heat-processes with respect to the 3rd mixture obtained at the said mixing process. The conditions for the heat treatment are preferably a heating temperature of 400 ° C. or higher and a temperature increase rate of 1 ° C./min or higher, particularly preferably 3 ° C./min or higher. If the heating temperature is less than 400 ° C., the formation of soft carbon becomes insufficient and the battery evaluation characteristics deteriorate. On the other hand, when the heating temperature is 1200 ° C. or higher, the reaction between the additive metal element and the graphite element easily occurs, and the battery evaluation characteristics are similarly deteriorated. On the other hand, when the rate of temperature increase is less than 1 ° C./min, the specific surface area of the composite active material is increased, the electrolyte is easily immersed, and the battery evaluation characteristics are deteriorated.
上記焼成で得られた複合活物質（第３混合物）は、さらに解砕、分級することができる。解砕、分級方法は特に限定しないが、解砕時に第１混合物を壊さない程度の解砕が必要であり、解砕力が弱いボールミルなどの方法が好ましい。また長時間の粉砕は、小粒径の分布が増え、電池評価の特性が低下する。
（第３実施態様）
複合活物質の製造方法の第３実施態様としては、所定の成分を含む第４混合物に球形化処理を施す球形化工程と、得られた第４混合物に対して加熱処理を施す加熱工程と、を有する方法が挙げられる。
The composite active material (third mixture) obtained by the firing can be further crushed and classified. The crushing and classification methods are not particularly limited, but crushing to the extent that the first mixture is not broken at the time of crushing is necessary, and a method such as a ball mill having a weak crushing force is preferable. Further, long-time pulverization increases the distribution of small particle diameters and degrades battery evaluation characteristics.
(Third embodiment)
As a third embodiment of the method for producing a composite active material, a spheronization step of subjecting a fourth mixture containing a predetermined component to a spheronization treatment, a heating step of subjecting the obtained fourth mixture to a heat treatment, The method which has this is mentioned.
以下、各工程の手順について詳述する。
［球形化工程］
球形化工程は、黒鉛成分、ハードカーボンの前駆体及びソフトカーボンの前駆体、および、リチウムイオンと化合可能な電池活物質を含む第４混合物に球形化処理を施す工程である。
Hereafter, the procedure of each process is explained in full detail.
[Spheronization process]
The spheronization step is a step of spheronizing a fourth mixture containing a graphite component, a hard carbon precursor and a soft carbon precursor, and a battery active material that can be combined with lithium ions.
使用される黒鉛成分、ハードカーボンの前駆体及びソフトカーボンの前駆体、および、電池活物質の定義は、上述の通りである。 The definitions of the graphite component, the hard carbon precursor and the soft carbon precursor, and the battery active material used are as described above.
第４混合物を得るための混合方法は特に制限されず、公知の方法を採用することができ、上記第１の実施形態の球形化処理にて述べた乾式処理または湿式処理などが挙げられる。 A mixing method for obtaining the fourth mixture is not particularly limited, and a known method can be adopted, and examples thereof include the dry process or the wet process described in the spheronization process of the first embodiment.
球形化処理の方法は、上記第１の実施形態の球形化処理の方法が挙げられる。 Examples of the spheronization processing method include the spheronization processing method of the first embodiment.
なお、球形化処理の前に、必要に応じて、得られた第４混合物をプレスするプレス工程が含まれていてもよい。
［加熱工程］
加熱工程は、上記球形化工程で得られた第４混合物に対して加熱処理を施す工程である。加熱処理の条件は、加熱温度４００℃以上、昇温速度を１℃／ｍｉｎ以上にすることが好ましく、３℃／ｍｉｎ以上とすることが特に好ましい。加熱温度が４００℃未満であると、ソフトカーボンの形成が不十分となり電池評価の特性が悪くなる。一方、加熱温度が１２００℃以上では、添加金属元素と黒鉛元素の反応が起き易く、同様に電池評価の特性が悪くなる。また、昇温速度が１℃／ｍｉｎ未満では、複合活物質の比表面積が大きくなり、電解液が浸漬し易く、電池評価の特性が低下する。
In addition, before the spheroidization treatment, a pressing step of pressing the obtained fourth mixture may be included as necessary.
[Heating process]
A heating process is a process of heat-processing with respect to the 4th mixture obtained at the said spheronization process. The heat treatment conditions are preferably a heating temperature of 400 ° C. or higher and a temperature increase rate of 1 ° C./min or higher, particularly preferably 3 ° C./min or higher. If the heating temperature is less than 400 ° C., the formation of soft carbon becomes insufficient and the battery evaluation characteristics deteriorate. On the other hand, when the heating temperature is 1200 ° C. or higher, the reaction between the additive metal element and the graphite element easily occurs, and the battery evaluation characteristics are similarly deteriorated. On the other hand, when the rate of temperature increase is less than 1 ° C./min, the specific surface area of the composite active material is increased, the electrolyte is easily immersed, and the battery evaluation characteristics are deteriorated.
上記焼成で得られた活物質（第４混合物）は、さらに解砕、分級することができる。解砕、分級方法は特に限定しないが、解砕時に第１混合物を壊さない程度の解砕が必要であり、解砕力が弱いボールミルなどの方法が好ましい。また長時間の粉砕は、小粒径の分布が増え、電池評価の特性が低下する。
（リチウム二次電池用負極材の製造方法）
本発明のリチウム二次電池用負極材の製造方法としては、例えば、リチウム二次電池用複合活物質の製造方法として好ましく用いられる上記第１実施態様〜第３実施態様の方法により得られたリチウム二次電池複合活物質と上記アクリル酸系重合体とを混合することにより製造することができる。
The active material (fourth mixture) obtained by the firing can be further crushed and classified. The crushing and classification methods are not particularly limited, but crushing to the extent that the first mixture is not broken at the time of crushing is necessary, and a method such as a ball mill having a weak crushing force is preferable. Further, long-time pulverization increases the distribution of small particle diameters and degrades battery evaluation characteristics.
(Method for producing negative electrode material for lithium secondary battery)
As a manufacturing method of the negative electrode material for lithium secondary batteries of the present invention, for example, lithium obtained by the method of the first to third embodiments preferably used as a manufacturing method of a composite active material for lithium secondary batteries. It can be manufactured by mixing the secondary battery composite active material and the acrylic acid polymer.
その際の混合方法としては、公知の方法を用いることができ特に限定されない。例えば、リチウム二次電池用複合活物質、アクリル酸系重合体、必要に応じて含有される導電助剤や増粘剤、塗工性（スラリー粘度）を調整するための水とを、自転・公転式ミキサー等の混合装置を使用して、撹拌・脱泡する方法が挙げられる。
＜リチウム二次電池＞
（負極）
負極は、本発明のリチウム二次電池用複合活物質とアクリル酸系重合体を混合（リチウム二次電池用負極材）し、溶剤を用いてスラリーとし、銅箔上に塗布してリチウム二次電池用負極とすることができる。
As a mixing method in that case, a well-known method can be used and it is not specifically limited. For example, a composite active material for a lithium secondary battery, an acrylic acid polymer, a conductive aid and a thickener contained as necessary, and water for adjusting coating properties (slurry viscosity), A method of stirring and defoaming using a mixing device such as a revolving mixer can be mentioned.
<Lithium secondary battery>
(Negative electrode)
The negative electrode is prepared by mixing the composite active material for a lithium secondary battery of the present invention and an acrylic acid polymer (a negative electrode material for a lithium secondary battery), forming a slurry using a solvent, and applying the slurry onto a copper foil. It can be set as the negative electrode for batteries.
なお、集電体としては銅箔以外に、電池のサイクルがより優れる点で、三次元構造を有する集電体が好ましい。三次元構造を有する集電体の材料としては、例えば、炭素繊維、スポンジ状カーボン（スポンジ状樹脂にカーボンを塗工したもの）、金属などが挙げられる。 In addition to the copper foil, the current collector is preferably a current collector having a three-dimensional structure in that the battery cycle is more excellent. Examples of the current collector material having a three-dimensional structure include carbon fiber, sponge-like carbon (a sponge-like resin coated with carbon), metal, and the like.
三次元構造を有する集電体（多孔質集電体）としては、金属や炭素の導電体の多孔質体として、平織り金網、エキスパンドメタル、ラス網、金属発泡体、金属織布、金属不織布、炭素繊維織布、または炭素繊維不織布などが挙げられる。 As a current collector (porous current collector) having a three-dimensional structure, a metal or carbon conductor porous body, a plain weave wire mesh, expanded metal, lath net, metal foam, metal woven fabric, metal nonwoven fabric, A carbon fiber woven fabric or a carbon fiber non-woven fabric may be used.
また、溶剤としては、例えば、水、イソプロピルアルコール、Ｎ−メチルピロリドン、ジメチルホルムアミドなどが挙げられる。 Examples of the solvent include water, isopropyl alcohol, N-methylpyrrolidone, dimethylformamide and the like.
なお、スラリーを調整する際には、上記のように必要に応じて、公知の攪拌機、混合機、混練機、ニーダーなどを用いて攪拌混合してもよい。 In addition, when adjusting a slurry, you may stir and mix using a well-known stirrer, a mixer, a kneader, a kneader, etc. as needed as mentioned above.
複合活物質を用いて塗工用スラリーを調製する場合、導電材として導電性カーボンブラック、カーボンナノチューブまたはその混合物を添加することが好ましい。上記工程により得られた複合活物質の形状は、比較的、粒状化（特に、略球形化）している場合が多く、粒子間の接触は点接触となりやすい。この弊害を避けるために、スラリーにカーボンブラック、カーボンナノチューブまたはその混合物を配合する方法が挙げられる。カーボンブラック、カーボンナノチューブまたはその混合物はスラリー溶剤の乾燥時に該複合活物質が接触して形成する毛細管部分に集中的に凝集することが出来るので、サイクルに伴う接点切れ（抵抗増大）を防止することが出来る。 When preparing a slurry for coating using a composite active material, it is preferable to add conductive carbon black, carbon nanotube, or a mixture thereof as a conductive material. The shape of the composite active material obtained by the above process is often relatively granulated (particularly, substantially spherical), and the contact between particles tends to be point contact. In order to avoid this adverse effect, a method of blending carbon black, carbon nanotubes or a mixture thereof into the slurry can be mentioned. Since carbon black, carbon nanotubes, or a mixture thereof can be intensively aggregated in the capillary part formed by contact with the composite active material when the slurry solvent is dried, contact loss (increased resistance) associated with the cycle is prevented. I can do it.
カーボンブラック、カーボンナノチューブまたはその混合物の配合量は特に制限されないが、複合活物質１００質量部に対して、０．２〜４質量部であることが好ましく、０．５〜２質量部であることがより好ましい。カーボンナノチューブの例としては、シングルウォールカーボンナノチューブ、マルチウォールカーボンナノチューブがある。
（正極）
正極としては、公知の正極材料を使用した正極を使用することができる。
The blending amount of carbon black, carbon nanotubes or a mixture thereof is not particularly limited, but is preferably 0.2 to 4 parts by mass, and 0.5 to 2 parts by mass with respect to 100 parts by mass of the composite active material. Is more preferable. Examples of the carbon nanotube include a single wall carbon nanotube and a multi-wall carbon nanotube.
(Positive electrode)
As the positive electrode, a positive electrode using a known positive electrode material can be used.
正極の製造方法としては公知の方法が挙げられ、正極材料と結合剤および導電剤よりなる正極合剤を集電体の表面に塗布する方法などが挙げられる。正極材料（正極活物質）としては、酸化クロム、酸化チタン、酸化コバルト、五酸化バナジウムなどの金属酸化物や、ＬｉＣｏＯ２、ＬｉＮｉＯ２、ＬｉＮｉ１−ｙＣｏｙＯ２、ＬｉＮｉ１−ｘ−ｙＣｏｘＡｌｙＯ２、ＬｉＭｎＯ２、ＬｉＭｎ２Ｏ４、ＬｉＦｅＯ２などのリチウム金属酸化物、硫化チタン、硫化モリブデンなどの遷移金属のカルコゲン化合物、または、ポリアセチレン、ポリパラフェニレン、ポリピロールなどの導電性を有する共役系高分子物質などが挙げられる。
（電解液）
電解液としては、公知の電解液を使用することができる。
As a manufacturing method of a positive electrode, a well-known method is mentioned, The method etc. which apply | coat the positive electrode mixture which consists of positive electrode material, a binder, and a electrically conductive agent to the surface of a collector are mentioned. Examples of the positive electrode material (positive electrode active material) include metal oxides such as chromium oxide, titanium oxide, cobalt oxide, and vanadium pentoxide, LiCoO 2 , LiNiO 2 , LiNi 1-y Co y O 2 , and LiNi 1-xy. Co x Al y O 2, LiMnO 2, LiMn 2 O 4, LiFeO 2 lithium metal oxides such as titanium sulfide, chalcogen compounds of transition metals such as molybdenum sulfide, or polyacetylene, polyparaphenylene, conductive polypyrrole Conjugated polymer substances having
(Electrolyte)
As the electrolytic solution, a known electrolytic solution can be used.
例えば、電解液中に含まれる電解質塩として、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＡｓＦ６、ＬｉＣｌＯ４、ＬｉＢ（Ｃ６Ｈ５）、ＬｉＣｌ、ＬｉＢｒ、ＬｉＣＦ３ＳＯ３、ＬｉＣＨ３ＳＯ３、ＬｉＮ（ＣＦ３ＳＯ２）２、ＬｉＣ（ＣＦ３ＳＯ２）３、ＬｉＮ（ＣＦ３ＣＨ２ＯＳＯ２）２、ＬｉＮ（ＣＦ３ＣＦ３ＯＳＯ２）２、ＬｉＮ（ＨＣＦ２ＣＦ２ＣＨ２ＯＳＯ２）２、ＬｉＮ｛（ＣＦ３）２ＣＨＯＳＯ２｝２、ＬｉＢ｛Ｃ６Ｈ３（ＣＦ３）２｝４、ＬｉＮ（ＳＯ２ＣＦ３）２、ＬｉＣ（ＳＯ２ＣＦ３）３、ＬｉＡｌＣｌ４、ＬｉＳｉＦ６などのリチウム塩を用いることができる。特にＬｉＰＦ６およびＬｉＢＦ４が酸化安定性の点から好ましい。 For example, as an electrolyte salt contained in the electrolyte, LiPF 6, LiBF 4, LiAsF 6, LiClO 4, LiB (C 6 H 5), LiCl, LiBr, LiCF 3 SO 3, LiCH 3 SO 3, LiN (CF 3 SO 2) 2, LiC (CF 3 SO 2) 3, LiN (CF 3 CH 2 OSO 2) 2, LiN (CF 3 CF 3 OSO 2) 2, LiN (HCF 2 CF 2 CH 2 OSO 2) 2, LiN {(CF 3 ) 2 CHOSO 2 } 2 , LiB {C 6 H 3 (CF 3 ) 2 } 4 , LiN (SO 2 CF 3 ) 2 , LiC (SO 2 CF 3 ) 3 , LiAlCl 4 , LiSiF 6 Lithium salts can be used. In particular, LiPF 6 and LiBF 4 are preferable from the viewpoint of oxidation stability.
電解質溶液中の電解質塩濃度は０．１〜５モル／リットルが好ましく、０．５〜３モル／リットルがより好ましい。 The electrolyte salt concentration in the electrolyte solution is preferably 0.1 to 5 mol / liter, and more preferably 0.5 to 3 mol / liter.
電解液で使用される溶媒としては、例えば、エチレンカーボネート、プロピレンカーボネート、ジメチルカーボネート、ジエチルカーボネートなどのカーボネート、１，１−または１，２−ジメトキシエタン、１，２−ジエトキシエタン、テトラヒドロフラン、２−メチルテトラヒドロフラン、γ−ブチロラクトン、１，３−ジオキソフラン、４−メチル−１，３−ジオキソラン、アニソール、ジエチルエーテルなどのエーテル、スルホラン、メチルスルホランなどのチオエーテル、アセトニトリル、クロロニトリル、プロピオニトリルなどのニトリル、ホウ酸トリメチル、ケイ酸テトラメチル、ニトロメタン、ジメチルホルムアミド、Ｎ−メチルピロリドン、酢酸エチル、トリメチルオルトホルメート、ニトロベンゼン、塩化ベンゾイル、臭化ベンゾイル、テトラヒドロチオフェン、ジメチルスルホキシド、３−メチル−２−オキサゾリン、エチレングリコール、ジメチルサルファイトなどの非プロトン性有機溶媒を用いることができる。 Examples of the solvent used in the electrolytic solution include carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, and diethyl carbonate, 1,1- or 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2 -Ethers such as methyltetrahydrofuran, γ-butyrolactone, 1,3-dioxofuran, 4-methyl-1,3-dioxolane, anisole and diethyl ether, thioethers such as sulfolane and methylsulfolane, acetonitrile, chloronitrile, propionitrile, etc. Nitrile, trimethyl borate, tetramethyl silicate, nitromethane, dimethylformamide, N-methylpyrrolidone, ethyl acetate, trimethyl orthoformate, nitrobenzene, benzoyl chloride, Benzoyl, tetrahydrothiophene, dimethyl sulfoxide, 3-methyl-2-oxazoline, ethylene glycol, may be used an aprotic organic solvent such as dimethyl sulfite.
なお、電解液の代わりに、高分子固体電解質、高分子ゲル電解質などの高分子電解質を使用してもよい。高分子固体電解質または高分子ゲル電解質のマトリクスを構成する高分子化合物としては、ポリエチレンオキサイドやその架橋体などのエーテル系高分子化合物、ポリメタクリレートなどのメタクリレート系高分子化合物、ポリアクリレートなどのアクリレート系高分子化合物、ポリビニリデンフルオライド（ＰＶＤＦ）やビニリデンフルオライド−ヘキサフルオロプロピレン共重合体などのフッ素系高分子化合物が好ましい。これらを混合して使用することもできる。酸化還元安定性などの観点から、ＰＶＤＦやビニリデンフルオライド−ヘキサフルオロプロピレン共重合体などのフッ素系高分子化合物が特に好ましい。
（セパレータ）
セパレータとしては、公知の材料を使用できる。例えば、織布、不織布、合成樹脂製微多孔膜などが例示される。合成樹脂製微多孔膜が好適であるが、なかでもポリオレフィン系微多孔膜が、膜厚、膜強度、膜抵抗などの点から好適である。具体的には、ポリエチレンおよびポリプロピレン製微多孔膜、またはこれらを複合した微多孔膜などである。
In place of the electrolytic solution, a polymer electrolyte such as a polymer solid electrolyte or a polymer gel electrolyte may be used. Examples of the polymer compound constituting the matrix of the polymer solid electrolyte or polymer gel electrolyte include ether polymer compounds such as polyethylene oxide and cross-linked products thereof, methacrylate polymer compounds such as polymethacrylate, and acrylate compounds such as polyacrylate. Fluorine polymer compounds such as polymer compounds, polyvinylidene fluoride (PVDF) and vinylidene fluoride-hexafluoropropylene copolymers are preferred. These can also be mixed and used. From the viewpoint of oxidation-reduction stability, a fluorine-based polymer compound such as PVDF or vinylidene fluoride-hexafluoropropylene copolymer is particularly preferable.
(Separator)
A known material can be used as the separator. For example, a woven fabric, a nonwoven fabric, a synthetic resin microporous film, etc. are illustrated. A synthetic resin microporous membrane is preferred, and among them, a polyolefin microporous membrane is preferred from the viewpoint of film thickness, membrane strength, membrane resistance, and the like. Specifically, it is a microporous film made of polyethylene and polypropylene, or a microporous film in which these are combined.
リチウム二次電池は、上述した負極、正極、セパレータ、電解液、その他電池構成要素（例えば、集電体、ガスケット、封口板、ケースなど）を用いて、常法にしたがって円筒型、角型あるいはボタン型などの形態を有することができる。 The lithium secondary battery uses the negative electrode, the positive electrode, the separator, the electrolyte, and other battery components (for example, a current collector, a gasket, a sealing plate, a case, etc.), and is cylindrical, square, or It can have a form such as a button type.
本発明のリチウム二次電池は、各種携帯電子機器に用いられ、特にノート型パソコン、ノート型ワープロ、パームトップ（ポケット）パソコン、携帯電話、携帯ファックス、携帯プリンター、ヘッドフォンステレオ、ビデオカメラ、携帯テレビ、ポータブルＣＤ、ポータブルＭＤ、電動髭剃り機、電子手帳、トランシーバー、電動工具、ラジオ、テープレコーダー、デジタルカメラ、携帯コピー機、携帯ゲーム機などに用いることができる。また、さらに、電気自動車、ハイブリッド自動車、自動販売機、電動カート、ロードレベリング用蓄電システム、家庭用蓄電器、分散型電力貯蔵機システム（据置型電化製品に内蔵）、非常時電力供給システムなどの二次電池として用いることもできる。 The lithium secondary battery of the present invention is used in various portable electronic devices, particularly notebook computers, notebook word processors, palmtop (pocket) computers, mobile phones, mobile faxes, mobile printers, headphone stereos, video cameras, and mobile TVs. , Portable CDs, portable MDs, electric shaving machines, electronic notebooks, transceivers, power tools, radios, tape recorders, digital cameras, portable copying machines, portable game machines, and the like. In addition, electric vehicles, hybrid vehicles, vending machines, electric carts, load leveling power storage systems, household power storage devices, distributed power storage systems (built into stationary appliances), emergency power supply systems, etc. It can also be used as a secondary battery.
以下、実施例により、本発明についてさらに詳細に説明するが、本発明はこれらに限定されるものではない。
＜合成例１＞リチウム二次電池用複合活物質の製造
（膨張黒鉛の調製）
平均粒子径１ｍｍの鱗片状天然黒鉛を硫酸９質量部、硝酸１質量部の混酸に室温で１時間浸漬後、Ｎｏ３ガラスフィルターで混酸を除去して酸処理黒鉛を得た。さらに酸処理黒鉛を水洗後、乾燥した。乾燥した酸処理黒鉛５ｇを蒸留水１００ｇ中で攪拌し、１時間後にｐＨを測定したところ、ｐＨは６．７であった。乾燥した酸処理黒鉛を８５０℃に設定した窒素雰囲気下の縦型電気炉に投入し、膨張黒鉛を得た。膨張黒鉛の嵩密度は０．００２ｇ／ｃｍ３、比表面積は４５ｍ２／ｇであった。
（混合工程）
平均粒子径０．３μｍのシリコン微粉末のエタノールスラーリー（固体濃度２６．６％、３７．５９質量部）をビーカー中で１６００質量部のエタノールに投入し、フェノール樹脂（炭化度４０％、５質量部）を加え、撹拌を行いながら１０分間、超音波処理を行った。
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.
<Synthesis Example 1> Production of composite active material for lithium secondary battery (preparation of expanded graphite)
After immersing scaly natural graphite having an average particle diameter of 1 mm in a mixed acid of 9 parts by mass of sulfuric acid and 1 part by mass of nitric acid at room temperature for 1 hour, the mixed acid was removed with a No 3 glass filter to obtain acid-treated graphite. Further, the acid-treated graphite was washed with water and dried. When 5 g of dried acid-treated graphite was stirred in 100 g of distilled water and the pH was measured after 1 hour, the pH was 6.7. The dried acid-treated graphite was put into a vertical electric furnace under a nitrogen atmosphere set at 850 ° C. to obtain expanded graphite. The expanded graphite had a bulk density of 0.002 g / cm 3 and a specific surface area of 45 m 2 / g.
(Mixing process)
An ethanol slurry of silicon fine powder having an average particle size of 0.3 μm (solid concentration: 26.6%, 37.59 parts by mass) was charged into 1600 parts by mass of ethanol in a beaker, and phenol resin (carbonization degree: 40%, 5% (Mass parts) was added and sonication was performed for 10 minutes while stirring.
シリコン微粉末、および、フェノール樹脂が分散したエタノール溶液に上記膨張黒鉛（１２質量部）を加え、膨張黒鉛とシリコン微粉末とフェノール樹脂とを含む均一混合スラリーを調製した。エバポレーターを用い、このスラリーからエタノールを回収し、粉末の混合物を得た。
（プレス工程）
３本ローラー（ＥＫＡＫＴ５０）を用い、上記粉末の混合物のプレスを行った。この処理で開いていた膨張黒鉛の層が閉じ、層間距離が縮まり、また密度も上昇し、次の球形化工程での衝突エネルギーを上昇させることで、球形化の効率を上げることが可能となる。
（球形化工程）
ニューパワーミル、ＰＭ−２００５Ｍ−１３８０Ｗ（大阪ケミカル株式会社）（回転速度：２００００ｒｐｍ、処理時間：９０秒を１０回）を用いて、上記で得られた粉末の混合物を球形状に造粒成形を行った。
（加熱処理（焼成、炭化処理））
窒素を流しながら（１Ｌ／ｍｉｎ）、球状の混合物を９００℃で１時間加熱することで、フェノール樹脂の炭化を同時に行った。これにより、黒鉛成分の含有量４０質量部、シリコンの含有量５０質量部、フェノール樹脂由来のハードカーボンの含有量１０質量部からなる略球形の混合物を得た。
（コールタールピッチによる被覆）
得らえた略球形の混合物（１００質量部）を、コールタールピッチ（炭化度４５％、６６．６７質量部）をキノリン（３００質量部）に溶解させた溶液中で加え、１０分間撹拌した後、以下の方法を用い焼成を行い、被覆を行った。
（焼成）
窒素を流しながら（１Ｌ／ｍｉｎ）、昇温度速度を５℃／ｍｉｎとし、混合物を９００℃で２時間加熱することで、コールタールピッチをソフトカーボンへ変性させた。これにより、黒鉛成分の含有量４０質量部、シリコンの含有量５０質量部、フェノール樹脂由来のハードカーボンの含有量１０質量部、コールタールピッチ由来のソフトカーボンの含有量１０質量部からなる略球形のリチウム二次電池用複合活物質を得た。
The expanded graphite (12 parts by mass) was added to a silicon fine powder and an ethanol solution in which a phenol resin was dispersed to prepare a homogeneous mixed slurry containing the expanded graphite, the silicon fine powder, and the phenol resin. Ethanol was recovered from this slurry using an evaporator to obtain a powder mixture.
(Pressing process)
Using a three-roller (EKAKT50), the powder mixture was pressed. The expanded graphite layer opened by this treatment is closed, the distance between the layers is reduced, the density is also increased, and the impact energy in the next spheronization process is increased, so that the efficiency of spheronization can be increased. .
(Spheronization process)
Using a new power mill, PM-2005M-1380W (Osaka Chemical Co., Ltd.) (rotation speed: 20000 rpm, treatment time: 90 seconds 10 times), the powder mixture obtained above is granulated into a spherical shape. went.
(Heat treatment (firing, carbonization))
While flowing nitrogen (1 L / min), the spherical mixture was heated at 900 ° C. for 1 hour to simultaneously carbonize the phenol resin. As a result, a substantially spherical mixture having a graphite component content of 40 parts by mass, a silicon content of 50 parts by mass, and a phenol resin-derived hard carbon content of 10 parts by mass was obtained.
(Coating with coal tar pitch)
The substantially spherical mixture obtained (100 parts by mass) was added to a solution obtained by dissolving coal tar pitch (carbonization degree 45%, 66.67 parts by mass) in quinoline (300 parts by mass), and stirred for 10 minutes. Then, firing was performed using the following method, and coating was performed.
(Baking)
While flowing nitrogen (1 L / min), the temperature rising rate was 5 ° C./min, and the mixture was heated at 900 ° C. for 2 hours to modify the coal tar pitch to soft carbon. Thus, a substantially spherical shape comprising a graphite component content of 40 parts by mass, a silicon content of 50 parts by mass, a phenolic resin-derived hard carbon content of 10 parts by mass, and a coal tar pitch-derived soft carbon content of 10 parts by mass. The composite active material for lithium secondary batteries was obtained.
その物性は以下の通りである。粒度分布Ｄ５０：１０．６μｍ、形状：略球状
１０ｋＶ以下の低加速電圧にて、ＳＥＭ（走査型電子顕微鏡）を用いて複合活物質の２次電子像から、複合活物質においては、黒鉛成分および電池活物質がソフトカーボンで覆われた構造であることが分かった。
The physical properties are as follows. Particle size distribution D50: 10.6 μm, shape: substantially spherical From a secondary electron image of the composite active material using a scanning electron microscope (SEM) at a low acceleration voltage of 10 kV or less, in the composite active material, the graphite component and It was found that the battery active material had a structure covered with soft carbon.
なお、ＳＥＭ観察により観察されるリチウム二次電池用複合活物質表面上に露出している露出しているシリコンの面積率は２％以下であった。 In addition, the area ratio of the exposed silicon exposed on the surface of the composite active material for a lithium secondary battery observed by SEM was 2% or less.
さらに、複合活物質中には、黒鉛が観察された。なお、黒鉛の厚みは２０ｎｍ程度（グラフェンシートの積総数６０）であった。
＜合成例２＞リチウム二次電池用複合活物質の製造
（膨張黒鉛の調製）
平均粒子径１ｍｍの鱗片状天然黒鉛を硫酸９質量部、硝酸１質量部の混酸に室温で１時間浸漬後、Ｎｏ３ガラスフィルターで混酸を除去して酸処理黒鉛を得た。さらに酸処理黒鉛を水洗後、乾燥した。乾燥した酸処理黒鉛５ｇを蒸留水１００ｇ中で攪拌し、１時間後にｐＨを測定したところ、ｐＨは６．７であった。乾燥した酸処理黒鉛を８５０℃に設定した窒素雰囲気下の縦型電気炉に投入し、膨張黒鉛を得た。膨張黒鉛の嵩密度は０．００２ｇ／ｃｍ３、比表面積は４５ｍ２／ｇであった。
（混合工程）
平均粒子径０．３μｍのシリコン微粉末のエタノールスラーリー（固体濃度２６．６％、３７．５９質量部）をビーカー中で１６００質量部のエタノールに投入し、フェノール樹脂（炭化度４０％、５質量部）を加え、撹拌を行いながら１０分間、超音波処理を行った。
Furthermore, graphite was observed in the composite active material. Note that the thickness of graphite was about 20 nm (total number of graphene sheets 60).
<Synthesis Example 2> Production of composite active material for lithium secondary battery (preparation of expanded graphite)
After immersing scaly natural graphite having an average particle diameter of 1 mm in a mixed acid of 9 parts by mass of sulfuric acid and 1 part by mass of nitric acid at room temperature for 1 hour, the mixed acid was removed with a No 3 glass filter to obtain acid-treated graphite. Further, the acid-treated graphite was washed with water and dried. When 5 g of dried acid-treated graphite was stirred in 100 g of distilled water and the pH was measured after 1 hour, the pH was 6.7. The dried acid-treated graphite was put into a vertical electric furnace under a nitrogen atmosphere set at 850 ° C. to obtain expanded graphite. The expanded graphite had a bulk density of 0.002 g / cm 3 and a specific surface area of 45 m 2 / g.
(Mixing process)
An ethanol slurry of silicon fine powder having an average particle size of 0.3 μm (solid concentration: 26.6%, 37.59 parts by mass) was charged into 1600 parts by mass of ethanol in a beaker, and phenol resin (carbonization degree: 40%, 5% (Mass parts) was added and sonication was performed for 10 minutes while stirring.
シリコン微粉末、および、フェノール樹脂が分散したエタノール溶液に上記膨張黒鉛（１２質量部）を加え、膨張黒鉛とシリコン微粉末とフェノール樹脂とを含む均一混合スラリーを調製した。エバポレーターを用い、このスラリーからエタノールを回収し、粉末の混合物を得た。
（プレス工程）
３本ローラー（ＥＫＡＫＴ５０）を用い、上記粉末の混合物のプレスを行った。この処理で開いていた膨張黒鉛の層が閉じ、層間距離が縮まり、また密度も上昇し、次の球形化工程での衝突エネルギーを上昇させることで、球形化の効率を上げることが可能となる。
（球形化工程）
ニューパワーミル、ＰＭ−２００５Ｍ−１３８０Ｗ（大阪ケミカル株式会社）（回転速度：２００００ｒｐｍ、処理時間：９０秒を１０回）を用いて、上記で得られた粉末の混合物を球形状に造粒成形を行った。
（加熱処理（焼成、炭化処理））
窒素を流しながら（１Ｌ／ｍｉｎ）、球状の混合物を９００℃で１時間加熱することで、フェノール樹脂の炭化を同時に行った。これにより、黒鉛成分の含有量４０質量部、シリコンの含有量５０質量部、フェノール樹脂由来のハードカーボンの含有量１０質量部からなる略球形の混合物を得た。
（コールタールピッチによる被覆）
得らえた略球形の混合物（１００質量部）を、コールタールピッチ（炭化度４５％、６６．６７質量部）をキノリン（３００質量部）に溶解させた溶液中で加え、１０分間撹拌した後、以下の方法を用い焼成を行い、被覆を行った。
（焼成）
窒素を流しながら（１Ｌ／ｍｉｎ）、昇温度速度を５℃／ｍｉｎとし、混合物を９００℃で２時間加熱することで、コールタールピッチをソフトカーボンへ変性させた。これにより、黒鉛成分の含有量４０質量部、シリコンの含有量５０質量部、フェノール樹脂由来のハードカーボンの含有量１０質量部、コールタールピッチ由来のソフトカーボンの含有量１０質量部からなる略球形のリチウム二次電池用複合活物質を得た。
The expanded graphite (12 parts by mass) was added to a silicon fine powder and an ethanol solution in which a phenol resin was dispersed to prepare a homogeneous mixed slurry containing the expanded graphite, the silicon fine powder, and the phenol resin. Ethanol was recovered from this slurry using an evaporator to obtain a powder mixture.
(Pressing process)
Using a three-roller (EKAKT50), the powder mixture was pressed. The expanded graphite layer opened by this treatment is closed, the distance between the layers is reduced, the density is also increased, and the impact energy in the next spheronization process is increased, so that the efficiency of spheronization can be increased. .
(Spheronization process)
Using a new power mill, PM-2005M-1380W (Osaka Chemical Co., Ltd.) (rotation speed: 20000 rpm, treatment time: 90 seconds 10 times), the powder mixture obtained above is granulated into a spherical shape. went.
(Heat treatment (firing, carbonization))
While flowing nitrogen (1 L / min), the spherical mixture was heated at 900 ° C. for 1 hour to simultaneously carbonize the phenol resin. As a result, a substantially spherical mixture having a graphite component content of 40 parts by mass, a silicon content of 50 parts by mass, and a phenol resin-derived hard carbon content of 10 parts by mass was obtained.
(Coating with coal tar pitch)
The substantially spherical mixture obtained (100 parts by mass) was added to a solution obtained by dissolving coal tar pitch (carbonization degree 45%, 66.67 parts by mass) in quinoline (300 parts by mass), and stirred for 10 minutes. Then, firing was performed using the following method, and coating was performed.
(Baking)
While flowing nitrogen (1 L / min), the temperature rising rate was 5 ° C./min, and the mixture was heated at 900 ° C. for 2 hours to modify the coal tar pitch to soft carbon. Thus, a substantially spherical shape comprising a graphite component content of 40 parts by mass, a silicon content of 50 parts by mass, a phenolic resin-derived hard carbon content of 10 parts by mass, and a coal tar pitch-derived soft carbon content of 10 parts by mass. The composite active material for lithium secondary batteries was obtained.
その物性は以下の通りである。粒度分布Ｄ５０：３１．７μｍ、ＢＥＴ比表面積：２９．５ｍ２／ｇ、形状：略球状
１０ｋＶ以下の低加速電圧にて、ＳＥＭ（走査型電子顕微鏡）を用いて複合活物質の２次電子像から、複合活物質においては、黒鉛成分および電池活物質がソフトカーボンで覆われた構造であることが分かった。
The physical properties are as follows. Particle size distribution D50: 31.7 μm, BET specific surface area: 29.5 m 2 / g, shape: substantially spherical Secondary electron image of composite active material using SEM (scanning electron microscope) at low acceleration voltage of 10 kV or less Thus, it was found that the composite active material had a structure in which the graphite component and the battery active material were covered with soft carbon.
また、上記（コールタールピッチによる被覆）を実施する前の略球形の混合物のＢＥＴ比表面積が５４ｍ２／ｇであり、得られた略球形のリチウム二次電池用複合活物質のＢＥＴ比表面積が２９．５ｍ２／ｇであり、ＢＥＴ比表面積が大きく低下している点からも、黒鉛成分および電池活物質がソフトカーボンで覆われた構造をとっていることが分かる。 Further, the BET specific surface area of the substantially spherical mixture before the above (coating with coal tar pitch) is 54 m 2 / g, and the obtained BET specific surface area of the substantially spherical composite active material for lithium secondary battery is 29.5m was 2 / g, from the viewpoint that the BET specific surface area is greatly reduced, it can be seen that the graphite components and battery active material is taking covered structure soft carbon.
なお、ＳＥＭ観察により観察されるリチウム二次電池用複合活物質表面上に露出している露出しているシリコンの面積率は２％以下であった。 In addition, the area ratio of the exposed silicon exposed on the surface of the composite active material for a lithium secondary battery observed by SEM was 2% or less.
さらに、複合活物質中には、黒鉛が観察された。なお、黒鉛の厚みは２０ｎｍ程度（グラフェンシートの積総数６０）であった。
＜実施例１＞
（アクリル酸系重合体の合成）
攪拌装置、温度計、冷却管、窒素ガス導入管、および滴下装置を備えた反応器に、水を２００質量部仕込み、撹拌しながら７５℃まで昇温した。そこに、アクリル酸１００質量部、過硫酸カリウム０．５質量部、水２５０質量部からなる混合物を、３時間かけて滴下した。滴下終了後、同温度で６時間反応させた。反応終了後冷却し、水酸化ナトリウム４７．２質量部，水３８４質量部を仕込み、中和することにより、固形分１３％、中和率８５％、重量平均分子量８２０，０００、粘度５０００ｍＰａ・ｓ（２５℃）のアクリル酸系重合体（ＡＡ−１４）を得た。
Furthermore, graphite was observed in the composite active material. Note that the thickness of graphite was about 20 nm (total number of graphene sheets 60).
<Example 1>
(Synthesis of acrylic acid polymer)
A reactor equipped with a stirrer, a thermometer, a cooling tube, a nitrogen gas introduction tube, and a dropping device was charged with 200 parts by mass of water, and the temperature was raised to 75 ° C. while stirring. The mixture which consists of 100 mass parts of acrylic acid, 0.5 mass part of potassium persulfate, and 250 mass parts of water was dripped there over 3 hours. After completion of dropping, the reaction was carried out at the same temperature for 6 hours. After completion of the reaction, the reaction mixture was cooled and charged with 47.2 parts by mass of sodium hydroxide and 384 parts by mass of water, and neutralized to obtain a solid content of 13%, a neutralization rate of 85%, a weight average molecular weight of 820,000, and a viscosity of 5000 mPa · s. An acrylic acid polymer (AA-14) of (25 ° C.) was obtained.
得られたアクリル酸系重合体７質量部、合成例１で得られたリチウム二次電池用複合活物質９２．５質量部、導電用カーボンブラック０．５質量部、および水１００質量部を秤り取り、自転・公転式ミキサーを用いて１０分間混合することで塗工用スラリー（リチウム二次電池用負極材）を調製した。
＜実施例２＞
（アクリル酸系重合体の合成）
攪拌装置、温度計、冷却管、窒素ガス導入管、および滴下装置を備えた反応器に、水を２００質量部仕込み、撹拌しながら７５℃まで昇温した。そこに、アクリル酸１００質量部、過硫酸カリウム２．２質量部、水２５０質量部からなる混合物を、３時間かけて滴下した。滴下終了後、同温度で６時間反応させた。反応終了後冷却し、水酸化ナトリウム４７．２質量部，水３９５質量部を仕込み、中和することにより、固形分１３％、中和率８５％、重量平均分子量２８０，０００、粘度８０ｍＰａ・ｓ（２５℃）のアクリル酸系重合体（ＡＡ−３９）を得た。
7 parts by mass of the obtained acrylic acid polymer, 92.5 parts by mass of the composite active material for lithium secondary battery obtained in Synthesis Example 1, 0.5 parts by mass of conductive carbon black, and 100 parts by mass of water were weighed. The slurry for coating was mixed for 10 minutes using a rotation / revolution mixer to prepare a slurry for coating (a negative electrode material for a lithium secondary battery).
<Example 2>
(Synthesis of acrylic acid polymer)
A reactor equipped with a stirrer, a thermometer, a cooling tube, a nitrogen gas introduction tube, and a dropping device was charged with 200 parts by mass of water, and the temperature was raised to 75 ° C. while stirring. There, the mixture which consists of 100 mass parts of acrylic acid, 2.2 mass parts of potassium persulfate, and 250 mass parts of water was dripped over 3 hours. After completion of dropping, the reaction was carried out at the same temperature for 6 hours. After completion of the reaction, the reaction mixture was cooled, and 47.2 parts by mass of sodium hydroxide and 395 parts by mass of water were added and neutralized to obtain a solid content of 13%, a neutralization rate of 85%, a weight average molecular weight of 280,000, and a viscosity of 80 mPa · s. An acrylic acid polymer (AA-39) of (25 ° C.) was obtained.
得られたアクリル酸系重合体７質量部、合成例１で得られたリチウム二次電池用複合活物質９２．５質量部、導電用カーボンブラック０．５質量部、および水１００質量部を秤り取り、型自転・公転式ミキサーを用いて１０分間混合することで塗工用スラリー（リチウム二次電池用負極材）を調製した。
＜実施例３＞
（アクリル酸系重合体の合成）
攪拌装置、温度計、冷却管、窒素ガス導入管、および滴下装置を備えた反応器に、水を２００質量部仕込み、撹拌しながら７５℃まで昇温した。そこに、アクリル酸１００質量部、過硫酸カリウム０．５質量部、水２５０質量部からなる混合物を、３時間かけて滴下した。滴下終了後、同温度で６時間反応させた。反応終了後冷却し、水酸化ナトリウム３３．３質量部，水３３６質量部を仕込み、中和することにより、固形分１３％、中和率６０％、重量平均分子量８２０，０００、粘度４５００ｍＰａ・ｓ（２５℃）のアクリル酸系重合体（ＡＡ−２５）を得た。
7 parts by mass of the obtained acrylic acid polymer, 92.5 parts by mass of the composite active material for lithium secondary battery obtained in Synthesis Example 1, 0.5 parts by mass of conductive carbon black, and 100 parts by mass of water were weighed. A slurry for coating (a negative electrode material for a lithium secondary battery) was prepared by mixing for 10 minutes using a mold rotation / revolution mixer.
<Example 3>
(Synthesis of acrylic acid polymer)
A reactor equipped with a stirrer, a thermometer, a cooling tube, a nitrogen gas introduction tube, and a dropping device was charged with 200 parts by mass of water, and the temperature was raised to 75 ° C. while stirring. The mixture which consists of 100 mass parts of acrylic acid, 0.5 mass part of potassium persulfate, and 250 mass parts of water was dripped there over 3 hours. After completion of dropping, the reaction was carried out at the same temperature for 6 hours. After completion of the reaction, the reaction mixture was cooled and charged with 33.3 parts by mass of sodium hydroxide and 336 parts by mass of water, and neutralized to obtain a solid content of 13%, a neutralization rate of 60%, a weight average molecular weight of 820,000, and a viscosity of 4500 mPa · s. An acrylic acid polymer (AA-25) of (25 ° C.) was obtained.
得られたアクリル酸系重合体７質量部、合成例１で得られたリチウム二次電池用複合活物質９２．５質量部、導電用カーボンブラック０．５質量部、および水１００質量部を秤り取り、自転・公転式ミキサーを用いて１０分間混合することで塗工用スラリー（リチウム二次電池用負極材）を調製した。
＜実施例４＞
（アクリル酸系重合体の合成）
攪拌装置、温度計、冷却管、窒素ガス導入管、および滴下装置を備えた反応器に、水を２００質量部仕込み、撹拌しながら７５℃まで昇温した。そこに、アクリル酸１００質量部、過硫酸カリウム０．５質量部、水２５０質量部からなる混合物を、３時間かけて滴下した。滴下終了後、同温度で６時間反応させた。反応終了後冷却し、水酸化リチウム２８．３質量部，水２５７質量部を仕込み、中和することにより、固形分１３％、中和率８５％、重量平均分子量８２０，０００、粘度１５０００ｍＰａ・ｓ（２５℃）のアクリル酸系重合体（ＡＡ−１４−２）を得た。
7 parts by mass of the obtained acrylic acid polymer, 92.5 parts by mass of the composite active material for lithium secondary battery obtained in Synthesis Example 1, 0.5 parts by mass of conductive carbon black, and 100 parts by mass of water were weighed. The slurry for coating was mixed for 10 minutes using a rotation / revolution mixer to prepare a slurry for coating (a negative electrode material for a lithium secondary battery).
<Example 4>
(Synthesis of acrylic acid polymer)
A reactor equipped with a stirrer, a thermometer, a cooling tube, a nitrogen gas introduction tube, and a dropping device was charged with 200 parts by mass of water, and the temperature was raised to 75 ° C. while stirring. The mixture which consists of 100 mass parts of acrylic acid, 0.5 mass part of potassium persulfate, and 250 mass parts of water was dripped there over 3 hours. After completion of dropping, the reaction was carried out at the same temperature for 6 hours. After completion of the reaction, the mixture was cooled, charged with 28.3 parts by mass of lithium hydroxide and 257 parts by mass of water, and neutralized to obtain a solid content of 13%, a neutralization rate of 85%, a weight average molecular weight of 820,000, and a viscosity of 15000 mPa · s. An acrylic acid polymer (AA-14-2) of (25 ° C.) was obtained.
得られたアクリル酸系重合体７質量部、合成例１で得られたリチウム二次電池用複合活物質９２．５質量部、導電用カーボンブラック０．５質量部、および水１００質量部を秤り取り、自転・公転式ミキサーを用いて１０分間混合することで塗工用スラリー（リチウム二次電池用負極材）を調製した。
＜実施例５＞
実施例１で用いたアクリル酸系重合体７質量部、合成例２で得られたリチウム二次電池用複合活物質９２．５質量部、導電用カーボンブラック０．５質量部、および水１００質量部を秤り取り、自転・公転式ミキサーを用いて１０分間混合することで塗工用スラリー（リチウム二次電池用負極材）を調製した。
＜参考例１＞
（膨張黒鉛の調製）
平均粒子径１ｍｍの鱗片状天然黒鉛を硫酸９質量部、硝酸１質量部の混酸に室温で１時間浸漬後、Ｎｏ３ガラスフィルターで混酸を除去して酸処理黒鉛を得た。さらに酸処理黒鉛を水洗後、乾燥した。乾燥した酸処理黒鉛５ｇを蒸留水１００ｇ中で攪拌し、１時間後にｐＨを測定したところ、ｐＨは６．７であった。乾燥した酸処理黒鉛を８５０℃に設定した窒素雰囲気下の縦型電気炉に投入し、膨張黒鉛を得た。膨張黒鉛の嵩密度は０．００２ｇ／ｃｍ３、比表面積は４５ｍ２／ｇであった。
（混合工程）
平均粒子径０．３μｍのシリコン微粉末のエタノールスラーリー（固体濃度２６．６％、２２．５６質量部）をビーカー中で１６００質量部のエタノールに投入し、フェノール樹脂（炭化度４０％、５質量部）を加え、撹拌を行いながら１０分間、超音波処理を行った。
7 parts by mass of the obtained acrylic acid polymer, 92.5 parts by mass of the composite active material for lithium secondary battery obtained in Synthesis Example 1, 0.5 parts by mass of conductive carbon black, and 100 parts by mass of water were weighed. The slurry for coating was mixed for 10 minutes using a rotation / revolution mixer to prepare a slurry for coating (a negative electrode material for a lithium secondary battery).
<Example 5>
7 parts by mass of the acrylic acid polymer used in Example 1, 92.5 parts by mass of the composite active material for lithium secondary battery obtained in Synthesis Example 2, 0.5 parts by mass of conductive carbon black, and 100 parts by mass of water The slurry was weighed and mixed for 10 minutes using a rotation / revolution mixer to prepare a slurry for coating (a negative electrode material for a lithium secondary battery).
<Reference Example 1>
(Preparation of expanded graphite)
After immersing scaly natural graphite having an average particle diameter of 1 mm in a mixed acid of 9 parts by mass of sulfuric acid and 1 part by mass of nitric acid at room temperature for 1 hour, the mixed acid was removed with a No 3 glass filter to obtain acid-treated graphite. Further, the acid-treated graphite was washed with water and dried. When 5 g of dried acid-treated graphite was stirred in 100 g of distilled water and the pH was measured after 1 hour, the pH was 6.7. The dried acid-treated graphite was put into a vertical electric furnace under a nitrogen atmosphere set at 850 ° C. to obtain expanded graphite. The expanded graphite had a bulk density of 0.002 g / cm 3 and a specific surface area of 45 m 2 / g.
(Mixing process)
An ethanol slurry of silicon fine powder having an average particle size of 0.3 μm (solid concentration 26.6%, 22.56 parts by mass) was introduced into 1600 parts by mass of ethanol in a beaker, and phenol resin (carbonization degree 40%, 5% (Mass parts) was added and sonication was performed for 10 minutes while stirring.
シリコン微粉末、および、フェノール樹脂が分散したエタノール溶液に上記膨張黒鉛（１２質量部）を加え、膨張黒鉛とシリコン微粉末とフェノール樹脂とを含む均一混合スラリーを調製した。エバポレーターを用い、このスラリーからエタノールを回収し、粉末の混合物を得た。
（プレス工程）
３本ローラー（ＥＫＡＫＴ５０）を用い、上記粉末の混合物のプレスを行った。この処理で開いていた膨張黒鉛の層が閉じ、層間距離が縮まり、また密度も上昇し、次の球形化工程での衝突エネルギーを上昇させることで、球形化の効率を上げることが可能となる。
（球形化工程）
ニューパワーミル、ＰＭ−２００５Ｍ−１３８０Ｗ（大阪ケミカル株式会社）（回転速度：２００００ｒｐｍ、処理時間：９０秒を１０回）を用いて、上記で得られた粉末の混合物を球形状に造粒成形を行った。
（加熱処理（焼成、炭化処理））
窒素を流しながら（１Ｌ／ｍｉｎ）、球状の混合物を９００℃で１時間加熱することで、フェノール樹脂の炭化を同時に行った。これにより、黒鉛成分の含有量６０質量部、シリコンの含有量３０質量部、フェノール樹脂由来のハードカーボンの含有量１０質量部からなる略球形の混合物を得た。
The expanded graphite (12 parts by mass) was added to a silicon fine powder and an ethanol solution in which a phenol resin was dispersed to prepare a homogeneous mixed slurry containing the expanded graphite, the silicon fine powder, and the phenol resin. Ethanol was recovered from this slurry using an evaporator to obtain a powder mixture.
(Pressing process)
Using a three-roller (EKAKT50), the powder mixture was pressed. The expanded graphite layer opened by this treatment is closed, the distance between the layers is reduced, the density is also increased, and the impact energy in the next spheronization process is increased, so that the efficiency of spheronization can be increased. .
(Spheronization process)
Using a new power mill, PM-2005M-1380W (Osaka Chemical Co., Ltd.) (rotation speed: 20000 rpm, treatment time: 90 seconds 10 times), the powder mixture obtained above is granulated into a spherical shape. went.
(Heat treatment (firing, carbonization))
While flowing nitrogen (1 L / min), the spherical mixture was heated at 900 ° C. for 1 hour to simultaneously carbonize the phenol resin. As a result, a substantially spherical mixture having a graphite component content of 60 parts by mass, a silicon content of 30 parts by mass, and a phenolic resin-derived hard carbon content of 10 parts by mass was obtained.
合成例１と同様に（膨張黒鉛の調製）、（混合工程）、（プレス工程）、および、（球形化工程）を実施して、略球形の混合物を得た。
（コールタールピッチとの混合）
得らえた略球形の混合物（１００質量部）を、コールタールピッチ（炭化度３８％、７８．６２質量部）をキノリン（１００質量部）に溶解させた溶液中で加え、１０分間撹拌し、混合物を得た。
（焼成）
窒素を流しながら（５Ｌ／ｍｉｎ）、昇温度速度を５℃／ｍｉｎとし、混合物を７５０℃で１時間、加熱することで、コールタールピッチをソフトカーボンへ変性させた。これにより、黒鉛成分の含有量６０質量部、シリコンの含有量３０質量部、フェノール樹脂由来のハードカーボンの含有量１０質量部、コールタールピッチ由来のソフトカーボンの含有量３０質量部からなる略球形のリチウム二次電池用複合活物質を得た。
(Synthesis of expanded graphite), (mixing step), (pressing step), and (spheronizing step) were performed in the same manner as in Synthesis Example 1 to obtain a substantially spherical mixture.
(Mixed with coal tar pitch)
The substantially spherical mixture obtained (100 parts by mass) was added in a solution obtained by dissolving coal tar pitch (carbonization degree 38%, 78.62 parts by mass) in quinoline (100 parts by mass), and stirred for 10 minutes. A mixture was obtained.
(Baking)
While flowing nitrogen (5 L / min), the temperature rising rate was 5 ° C./min, and the mixture was heated at 750 ° C. for 1 hour to modify the coal tar pitch to soft carbon. Thus, a substantially spherical shape comprising a graphite component content of 60 parts by mass, a silicon content of 30 parts by mass, a phenolic resin-derived hard carbon content of 10 parts by mass, and a coal tar pitch-derived soft carbon content of 30 parts by mass. The composite active material for lithium secondary batteries was obtained.
その物性は以下の通りである。粒度分布Ｄ５０：１２μｍ、Ｄ９０：２７μｍ、比表面積：２２．０ｍ２／ｇ、形状：略球状
１０ｋＶ以下の低加速電圧にて、ＳＥＭ（走査型電子顕微鏡）を用いて複合活物質の２次電子像から、複合活物質においては、黒鉛成分および電池活物質がソフトカーボンで覆われた構造であることが分かった。
The physical properties are as follows. Particle size distribution D50: 12 μm, D90: 27 μm, specific surface area: 22.0 m 2 / g, shape: substantially spherical Secondary electron of composite active material using SEM (scanning electron microscope) at low acceleration voltage of 10 kV or less From the image, it was found that the composite active material had a structure in which the graphite component and the battery active material were covered with soft carbon.
また、複合活物質中には、薄片化黒鉛が観察された。なお、薄片化黒鉛の厚みは２０ｎｍ程度（グラフェンシートの積総数６０）であった。また、同様に浸漬の有無を確認した結果、浸漬は認められなかった。 Further, exfoliated graphite was observed in the composite active material. The thickness of exfoliated graphite was about 20 nm (total number of graphene sheets 60). Moreover, as a result of confirming the presence or absence of immersion similarly, immersion was not recognized.
得られた複合活物質を９５．５質量部（固形分全量中の含有量。以下同じ。）に対して、導電助剤としてアセチレンブラック０．５質量部と、バインダーとしてＣＭＣ１．５質量部とＳＢＲ２．５質量部、水とを混合して負極合剤含有スラリー（リチウム二次電池用負極材）を調製した。
＜参考例２＞
参考例１と同様に（膨張黒鉛の調製）、（混合工程）、（プレス工程）、および、（球形化工程）を実施して、略球形の混合物を得た。
（コールタールピッチとの混合）
得らえた略球形の混合物（１００質量部）を、コールタールピッチ（炭化度３８％、１３１．５８質量部）をキノリン（１００質量部）に溶解させた溶液中で加え、１０分間撹拌し、混合物を得た。
（焼成）
窒素を流しながら（５Ｌ／ｍｉｎ）、昇温度速度を５℃／ｍｉｎとし、混合物を６００℃で２時間、加熱することで、コールタールピッチをソフトカーボンへ変性させた。これにより、黒鉛成分の含有量６０質量部、シリコンの含有量３０質量部、フェノール樹脂由来のハードカーボンの含有量１０質量部、コールタールピッチ由来のソフトカーボンの含有量５０質量部からなる略球形のリチウム二次電池用複合活物質を得た。
With respect to 95.5 parts by mass of the obtained composite active material (content in the total amount of solids, the same applies hereinafter), 0.5 part by mass of acetylene black as a conductive assistant, 1.5 parts by mass of CMC as a binder, 2.5 parts by mass of SBR and water were mixed to prepare a negative electrode mixture-containing slurry (a negative electrode material for a lithium secondary battery).
<Reference Example 2>
In the same manner as in Reference Example 1 (preparation of expanded graphite), (mixing step), (pressing step), and (spheronizing step), a substantially spherical mixture was obtained.
(Mixed with coal tar pitch)
The obtained substantially spherical mixture (100 parts by mass) was added in a solution in which coal tar pitch (carbonization degree 38%, 131.58 parts by mass) was dissolved in quinoline (100 parts by mass), and stirred for 10 minutes. A mixture was obtained.
(Baking)
While flowing nitrogen (5 L / min), the temperature rising rate was 5 ° C./min, and the mixture was heated at 600 ° C. for 2 hours to modify the coal tar pitch to soft carbon. Thus, a substantially spherical shape comprising a graphite component content of 60 parts by mass, a silicon content of 30 parts by mass, a phenol resin-derived hard carbon content of 10 parts by mass, and a coal tar pitch-derived soft carbon content of 50 parts by mass. The composite active material for lithium secondary batteries was obtained.
その物性は以下の通りである。粒度分布Ｄ５０：１９μｍ、Ｄ９０：３５μｍ、比表面積：１０．０ｍ２／ｇ、形状：略球状
１０ｋＶ以下の低加速電圧にて、ＳＥＭ（走査型電子顕微鏡）を用いて複合活物質の２次電子像から、複合活物質においては、黒鉛成分および電池活物質がソフトカーボンで覆われた構造であることが分かった。
The physical properties are as follows. Particle size distribution D50: 19 μm, D90: 35 μm, specific surface area: 10.0 m 2 / g, shape: substantially spherical Secondary electron of composite active material using SEM (scanning electron microscope) at low acceleration voltage of 10 kV or less From the image, it was found that the composite active material had a structure in which the graphite component and the battery active material were covered with soft carbon.
また、複合活物質中には、薄片化黒鉛が観察された。なお、薄片化黒鉛の厚みは２０ｎｍ程度（グラフェンシートの積総数６０）であった。また、同様に電解液浸漬の有無を確認した結果、浸漬は認められなかった。 Further, exfoliated graphite was observed in the composite active material. The thickness of exfoliated graphite was about 20 nm (total number of graphene sheets 60). Moreover, as a result of confirming the presence or absence of electrolyte solution immersion similarly, immersion was not recognized.
参考例１と同様に負極合剤含有スラリー（リチウム二次電池用負極材）を調製した。
［リチウム二次電池の評価］
実施例１〜６、及び参考例１，２で得られたスラリー（リチウム二次電池用負極材）を、アプリケータを用いて固形分塗布量が３ｍｇ／ｃｍ２になるように厚みが１５μｍの銅箔に塗布し、１１０℃で定置運転乾燥機にて０．５時間乾燥した。乾燥後、１４ｍｍφの円形に打ち抜き、さらに真空下、１１０℃で３時間熱処理して、負極合剤層を形成したリチウムイオン２次電池用負極を得た。
A negative electrode mixture-containing slurry (a negative electrode material for a lithium secondary battery) was prepared in the same manner as in Reference Example 1.
[Evaluation of lithium secondary battery]
The slurry (negative electrode material for lithium secondary battery) obtained in Examples 1 to 6 and Reference Examples 1 and 2 has a thickness of 15 μm using an applicator so that the solid content is 3 mg / cm 2 . It apply | coated to copper foil and it dried at 110 degreeC with the stationary operation dryer for 0.5 hour. After drying, it was punched into a circle of 14 mmφ, and further heat-treated at 110 ° C. for 3 hours under vacuum to obtain a negative electrode for a lithium ion secondary battery in which a negative electrode mixture layer was formed.
（評価用ハーフセルの作製）
評価用セルは、グローブボックス中でスクリューセルに上記負極、２４ｍｍφのポリプロピレン製セパレータ、２１ｍｍφのガラスフィルター、１８ｍｍφで厚み０．２ｍｍの金属リチウムおよびその基材のステンレス箔を、各々、電解液にディップしたのち、この順に積層し、最後に蓋をねじ込み作製した。電解液はエチレンカーボネートとジエチルカーボネートを体積比１対１の混合溶媒とし、ＬｉＰＦ６を１．２ｍｏｌ／Ｌの濃度になるように溶解させ、これにフルオロエチレンカーボネートを２体積％添加したものを使用した。評価用セルは、さらにシリカゲルを入れた密閉ガラス容器に入れて、シリコンゴムの蓋を通した電極を充放電装置に接続した。
(Production of evaluation half-cell)
In the glove box, the evaluation cell was prepared by dipping the negative electrode, a 24 mmφ polypropylene separator, a 21 mmφ glass filter, a 18 mmφ 0.2 mm thick metal lithium and a stainless steel foil of the base material into the electrolyte solution in the glove box. After that, the layers were laminated in this order, and finally the lid was screwed in. The electrolyte used was a mixture of ethylene carbonate and diethyl carbonate in a volume ratio of 1: 1, dissolved LiPF 6 to a concentration of 1.2 mol / L, and added with 2% by volume of fluoroethylene carbonate. did. The evaluation cell was further placed in a sealed glass container containing silica gel, and an electrode through a silicon rubber lid was connected to the charge / discharge device.
（ハーフセル評価条件）
ハーフ評価用セルは２５℃の恒温室にて、サイクル試験した。充電は、２ｍＡの定電流で０．０１Ｖまで充電後、０．０１Ｖの定電圧で電流値が０．２ｍＡになるまで行った。また放電は、２ｍＡの定電流で１．５Ｖの電圧値まで行った。放電容量と初期充放電効率は、初回充放電試験の結果とした。
(Half-cell evaluation conditions)
The half evaluation cell was subjected to a cycle test in a constant temperature room at 25 ° C. Charging was performed after charging to 0.01 V at a constant current of 2 mA until the current value reached 0.2 mA at a constant voltage of 0.01 V. The discharge was performed at a constant current of 2 mA up to a voltage value of 1.5 V. The discharge capacity and the initial charge / discharge efficiency were the results of the initial charge / discharge test.
また、サイクル特性は、前記充放電条件にて５０回及充放電試験した後の放電容量を初回の放電容量を比較し、その容量維持率として評価した。 In addition, the cycle characteristics were evaluated as the capacity retention ratio by comparing the discharge capacity after 50 charge / discharge tests under the charge / discharge conditions with the initial discharge capacity.
Claims (13)
球形化処理が施された前記第１混合物に対して加熱処理を施す第１加熱工程と、
前記第１加熱工程で得られた焼成物とソフトカーボンの前駆体とを混合して第２混合物を得る混合工程と、
前記第２混合物に対して加熱処理を施す第２加熱工程によりリチウム二次電池用複合活物質を製造した後、アクリル酸系重合体を混合する請求項１〜７のいずれかに記載のリチウム二次電池用負極材の製造方法 A spheronization step of spheronizing a first mixture containing a graphite component and a battery active material that can be combined with lithium ions;
A first heating step of performing a heat treatment on the first mixture subjected to the spheroidization treatment;
A mixing step of mixing the fired product obtained in the first heating step and a precursor of soft carbon to obtain a second mixture;
The lithium secondary battery according to any one of claims 1 to 7, wherein the acrylic polymer is mixed after the composite active material for a lithium secondary battery is manufactured by a second heating step in which heat treatment is performed on the second mixture. Method for manufacturing negative electrode material for secondary battery
球形化処理が施された第１混合物とソフトカーボンの前駆体とを混合して第３混合物を得る混合工程と、
前記第３混合物に対して加熱処理を施す加熱工程によりリチウム二次電池用複合活物質を製造した後、アクリル酸系重合体を混合する請求項１〜７のいずれかに記載のリチウム二次電池用負極材の製造方法。 A spheronization step of spheronizing a first mixture containing a graphite component and a battery active material that can be combined with lithium ions;
A mixing step of mixing a spheroidized first mixture and a soft carbon precursor to obtain a third mixture;
The lithium secondary battery according to any one of claims 1 to 7, wherein an acrylic acid polymer is mixed after the composite active material for a lithium secondary battery is manufactured by a heating step of performing a heat treatment on the third mixture. Manufacturing method for negative electrode material.
球形化処理が施された前記第４混合物に対して加熱処理を施す加熱工程によりリチウム二次電池用複合活物質を製造した後、アクリル酸系重合体を混合する請求項１〜７のいずれかに記載のリチウム二次電池用負極材の製造方法。 A spheronization step of spheronizing a fourth mixture containing a graphite component, a hard carbon, a precursor of soft carbon, and a battery active material that can be combined with lithium ions;
Any one of Claims 1-7 which mixes an acrylic acid polymer after manufacturing the composite active material for lithium secondary batteries by the heating process which heat-processes with respect to the said 4th mixture in which the spheroidization process was performed. The manufacturing method of the negative electrode material for lithium secondary batteries as described in 2 ..
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016007154A JP2017130274A (en) | 2016-01-18 | 2016-01-18 | Negative electrode material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016007154A JP2017130274A (en) | 2016-01-18 | 2016-01-18 | Negative electrode material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2017130274A true JP2017130274A (en) | 2017-07-27 |
Family
ID=59396266
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2016007154A Pending JP2017130274A (en) | 2016-01-18 | 2016-01-18 | Negative electrode material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2017130274A (en) |
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108598476A (en) * | 2018-03-11 | 2018-09-28 | 贵州格瑞特新材料有限公司 | A kind of negative electrode of lithium ion battery high first spherical hard carbon material of effect and preparation method thereof |
| EP3439078A1 (en) * | 2017-07-31 | 2019-02-06 | Honda Motor Co., Ltd. | Continuous production of binder and collector-less self-standing electrodes for li-ion batteries by using carbon nanotubes as an additive |
| CN109817886A (en) * | 2018-12-29 | 2019-05-28 | 深圳市卓能新能源股份有限公司 | Battery cathode sheet and preparation method thereof and lithium ion battery |
| WO2019107936A1 (en) * | 2017-11-28 | 2019-06-06 | 주식회사 엘지화학 | Negative electrode active material, negative electrode and lithium secondary battery comprising same |
| WO2019150909A1 (en) * | 2018-01-30 | 2019-08-08 | 日本ゼオン株式会社 | Additive for electrochemical element, binder composition for electrochemical element, slurry composition for electrochemical element, electrode for electrochemical element, and electrochemical element |
| CN110544766A (en) * | 2019-09-23 | 2019-12-06 | 七台河万锂泰电材有限公司 | Expanded graphite nano-silicon composite negative electrode material and preparation method thereof |
| US10658651B2 (en) | 2017-07-31 | 2020-05-19 | Honda Motor Co., Ltd. | Self standing electrodes and methods for making thereof |
| US11081684B2 (en) | 2017-05-24 | 2021-08-03 | Honda Motor Co., Ltd. | Production of carbon nanotube modified battery electrode powders via single step dispersion |
| CN113363467A (en) * | 2021-06-18 | 2021-09-07 | 广东凯金新能源科技股份有限公司 | Nitrogen-doped high-capacity hard carbon negative electrode material and preparation method thereof |
| US11121358B2 (en) | 2017-09-15 | 2021-09-14 | Honda Motor Co., Ltd. | Method for embedding a battery tab attachment in a self-standing electrode without current collector or binder |
| US11171324B2 (en) | 2016-03-15 | 2021-11-09 | Honda Motor Co., Ltd. | System and method of producing a composite product |
| US11201318B2 (en) | 2017-09-15 | 2021-12-14 | Honda Motor Co., Ltd. | Method for battery tab attachment to a self-standing electrode |
| CN113964305A (en) * | 2021-10-22 | 2022-01-21 | 湖北亿纬动力有限公司 | Silicon-carbon composite negative electrode material, preparation method thereof and lithium ion battery |
| US11325833B2 (en) | 2019-03-04 | 2022-05-10 | Honda Motor Co., Ltd. | Composite yarn and method of making a carbon nanotube composite yarn |
| US11352258B2 (en) | 2019-03-04 | 2022-06-07 | Honda Motor Co., Ltd. | Multifunctional conductive wire and method of making |
| US11383213B2 (en) | 2016-03-15 | 2022-07-12 | Honda Motor Co., Ltd. | System and method of producing a composite product |
| CN114824689A (en) * | 2021-01-20 | 2022-07-29 | Fdk株式会社 | Laminated electric storage device |
| CN114927679A (en) * | 2022-03-07 | 2022-08-19 | 上海兰钧新能源科技有限公司 | Lithium battery negative electrode slurry and preparation method thereof |
| US11539042B2 (en) | 2019-07-19 | 2022-12-27 | Honda Motor Co., Ltd. | Flexible packaging with embedded electrode and method of making |
| US11535517B2 (en) | 2019-01-24 | 2022-12-27 | Honda Motor Co., Ltd. | Method of making self-standing electrodes supported by carbon nanostructured filaments |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005123175A (en) * | 2003-09-26 | 2005-05-12 | Jfe Chemical Corp | Composite particle, manufacturing method of the same, negative electrode material and negative electrode for lithium-ion secondary battery, and the lithium-ion secondary battery |
| JP2007035434A (en) * | 2005-07-27 | 2007-02-08 | Matsushita Electric Ind Co Ltd | Nonaqueous electrolyte battery |
| JP2011076741A (en) * | 2009-09-29 | 2011-04-14 | Sumitomo Bakelite Co Ltd | Lithium secondary battery negative electrode mixture, lithium secondary battery negative electrode, and lithium secondary battery |
| JP2011192629A (en) * | 2010-02-19 | 2011-09-29 | Panasonic Corp | Coin-shaped lithium secondary battery |
| WO2012120895A1 (en) * | 2011-03-09 | 2012-09-13 | パナソニック株式会社 | Terminal-equipped battery |
| US20130244106A1 (en) * | 2011-02-15 | 2013-09-19 | Lg Chem, Ltd. | Process for preparation of anode active material |
| JP2015079621A (en) * | 2013-10-16 | 2015-04-23 | 三菱化学株式会社 | Composite graphite particle for nonaqueous secondary battery negative electrodes, negative electrode for nonaqueous secondary batteries, and nonaqueous secondary battery |
| JP2015106563A (en) * | 2013-11-29 | 2015-06-08 | 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 | SIOx BASED COMPOSITE NEGATIVE ELECTRODE MATERIAL, PREPARATION METHOD AND BATTERY |
| WO2015098050A1 (en) * | 2013-12-26 | 2015-07-02 | 日本ゼオン株式会社 | Slurry composition for negative electrodes of lithium ion secondary batteries, negative electrode for lithium ion secondary batteries, and lithium ion secondary battery |
| JP2015195171A (en) * | 2014-03-25 | 2015-11-05 | 東ソー株式会社 | Negative electrode active material for lithium ion secondary battery and method of manufacturing the same |
| JP2016149340A (en) * | 2015-02-06 | 2016-08-18 | 東ソー株式会社 | Composite active material for lithium secondary battery, manufacturing method for the same and lithium secondary battery |
| US20170084913A1 (en) * | 2014-03-25 | 2017-03-23 | Tosoh Corporation | Composite active material for lithium ion secondary batteries and method for producing same |
-
2016
- 2016-01-18 JP JP2016007154A patent/JP2017130274A/en active Pending
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005123175A (en) * | 2003-09-26 | 2005-05-12 | Jfe Chemical Corp | Composite particle, manufacturing method of the same, negative electrode material and negative electrode for lithium-ion secondary battery, and the lithium-ion secondary battery |
| JP2007035434A (en) * | 2005-07-27 | 2007-02-08 | Matsushita Electric Ind Co Ltd | Nonaqueous electrolyte battery |
| JP2011076741A (en) * | 2009-09-29 | 2011-04-14 | Sumitomo Bakelite Co Ltd | Lithium secondary battery negative electrode mixture, lithium secondary battery negative electrode, and lithium secondary battery |
| JP2011192629A (en) * | 2010-02-19 | 2011-09-29 | Panasonic Corp | Coin-shaped lithium secondary battery |
| US20130244106A1 (en) * | 2011-02-15 | 2013-09-19 | Lg Chem, Ltd. | Process for preparation of anode active material |
| WO2012120895A1 (en) * | 2011-03-09 | 2012-09-13 | パナソニック株式会社 | Terminal-equipped battery |
| JP2015079621A (en) * | 2013-10-16 | 2015-04-23 | 三菱化学株式会社 | Composite graphite particle for nonaqueous secondary battery negative electrodes, negative electrode for nonaqueous secondary batteries, and nonaqueous secondary battery |
| JP2015106563A (en) * | 2013-11-29 | 2015-06-08 | 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 | SIOx BASED COMPOSITE NEGATIVE ELECTRODE MATERIAL, PREPARATION METHOD AND BATTERY |
| WO2015098050A1 (en) * | 2013-12-26 | 2015-07-02 | 日本ゼオン株式会社 | Slurry composition for negative electrodes of lithium ion secondary batteries, negative electrode for lithium ion secondary batteries, and lithium ion secondary battery |
| JP2015195171A (en) * | 2014-03-25 | 2015-11-05 | 東ソー株式会社 | Negative electrode active material for lithium ion secondary battery and method of manufacturing the same |
| US20170084913A1 (en) * | 2014-03-25 | 2017-03-23 | Tosoh Corporation | Composite active material for lithium ion secondary batteries and method for producing same |
| JP2016149340A (en) * | 2015-02-06 | 2016-08-18 | 東ソー株式会社 | Composite active material for lithium secondary battery, manufacturing method for the same and lithium secondary battery |
Cited By (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11888152B2 (en) | 2016-03-15 | 2024-01-30 | Honda Motor Co., Ltd. | System and method of producing a composite product |
| US11383213B2 (en) | 2016-03-15 | 2022-07-12 | Honda Motor Co., Ltd. | System and method of producing a composite product |
| US11171324B2 (en) | 2016-03-15 | 2021-11-09 | Honda Motor Co., Ltd. | System and method of producing a composite product |
| US11735705B2 (en) | 2017-05-24 | 2023-08-22 | Honda Motor Co., Ltd. | Production of carbon nanotube modified battery electrode powders via single step dispersion |
| US11081684B2 (en) | 2017-05-24 | 2021-08-03 | Honda Motor Co., Ltd. | Production of carbon nanotube modified battery electrode powders via single step dispersion |
| US11374214B2 (en) | 2017-07-31 | 2022-06-28 | Honda Motor Co., Ltd. | Self standing electrodes and methods for making thereof |
| EP3439078A1 (en) * | 2017-07-31 | 2019-02-06 | Honda Motor Co., Ltd. | Continuous production of binder and collector-less self-standing electrodes for li-ion batteries by using carbon nanotubes as an additive |
| US10658651B2 (en) | 2017-07-31 | 2020-05-19 | Honda Motor Co., Ltd. | Self standing electrodes and methods for making thereof |
| US11569490B2 (en) | 2017-07-31 | 2023-01-31 | Honda Motor Co., Ltd. | Continuous production of binder and collector-less self-standing electrodes for Li-ion batteries by using carbon nanotubes as an additive |
| US11489147B2 (en) | 2017-09-15 | 2022-11-01 | Honda Motor Co., Ltd. | Method for embedding a battery tab attachment in a self-standing electrode without current collector or binder |
| US11121358B2 (en) | 2017-09-15 | 2021-09-14 | Honda Motor Co., Ltd. | Method for embedding a battery tab attachment in a self-standing electrode without current collector or binder |
| US11616221B2 (en) | 2017-09-15 | 2023-03-28 | Honda Motor Co., Ltd. | Method for battery tab attachment to a self-standing electrode |
| US11201318B2 (en) | 2017-09-15 | 2021-12-14 | Honda Motor Co., Ltd. | Method for battery tab attachment to a self-standing electrode |
| US11476453B2 (en) | 2017-11-28 | 2022-10-18 | Lg Energy Solution, Ltd. | Negative electrode active material, and negative electrode and lithium secondary battery comprising same |
| WO2019107936A1 (en) * | 2017-11-28 | 2019-06-06 | 주식회사 엘지화학 | Negative electrode active material, negative electrode and lithium secondary battery comprising same |
| JPWO2019150909A1 (en) * | 2018-01-30 | 2021-02-12 | 日本ゼオン株式会社 | Additives for electrochemical elements, binder compositions for electrochemical elements, slurry compositions for electrochemical elements, electrodes for electrochemical elements, and electrochemical elements |
| JP7314802B2 (en) | 2018-01-30 | 2023-07-26 | 日本ゼオン株式会社 | Additive for electrochemical element, binder composition for electrochemical element, slurry composition for electrochemical element, electrode for electrochemical element, and electrochemical element |
| US11302923B2 (en) | 2018-01-30 | 2022-04-12 | Zeon Corporation | Additive for electrochemical device, binder composition for electrochemical device, slurry composition for electrochemical device, electrode for electrochemical device, and electrochemical device |
| WO2019150909A1 (en) * | 2018-01-30 | 2019-08-08 | 日本ゼオン株式会社 | Additive for electrochemical element, binder composition for electrochemical element, slurry composition for electrochemical element, electrode for electrochemical element, and electrochemical element |
| CN108598476A (en) * | 2018-03-11 | 2018-09-28 | 贵州格瑞特新材料有限公司 | A kind of negative electrode of lithium ion battery high first spherical hard carbon material of effect and preparation method thereof |
| CN109817886A (en) * | 2018-12-29 | 2019-05-28 | 深圳市卓能新能源股份有限公司 | Battery cathode sheet and preparation method thereof and lithium ion battery |
| US11535517B2 (en) | 2019-01-24 | 2022-12-27 | Honda Motor Co., Ltd. | Method of making self-standing electrodes supported by carbon nanostructured filaments |
| US11325833B2 (en) | 2019-03-04 | 2022-05-10 | Honda Motor Co., Ltd. | Composite yarn and method of making a carbon nanotube composite yarn |
| US11352258B2 (en) | 2019-03-04 | 2022-06-07 | Honda Motor Co., Ltd. | Multifunctional conductive wire and method of making |
| US11834335B2 (en) | 2019-03-04 | 2023-12-05 | Honda Motor Co., Ltd. | Article having multifunctional conductive wire |
| US11539042B2 (en) | 2019-07-19 | 2022-12-27 | Honda Motor Co., Ltd. | Flexible packaging with embedded electrode and method of making |
| CN110544766A (en) * | 2019-09-23 | 2019-12-06 | 七台河万锂泰电材有限公司 | Expanded graphite nano-silicon composite negative electrode material and preparation method thereof |
| CN114824689A (en) * | 2021-01-20 | 2022-07-29 | Fdk株式会社 | Laminated electric storage device |
| CN113363467A (en) * | 2021-06-18 | 2021-09-07 | 广东凯金新能源科技股份有限公司 | Nitrogen-doped high-capacity hard carbon negative electrode material and preparation method thereof |
| CN113964305A (en) * | 2021-10-22 | 2022-01-21 | 湖北亿纬动力有限公司 | Silicon-carbon composite negative electrode material, preparation method thereof and lithium ion battery |
| CN114927679A (en) * | 2022-03-07 | 2022-08-19 | 上海兰钧新能源科技有限公司 | Lithium battery negative electrode slurry and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2017130274A (en) | Negative electrode material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery | |
| US20190088935A1 (en) | Composite active material for lithium secondary batteries and method for producing same | |
| JP6334195B2 (en) | Composite active material for lithium secondary battery and method for producing the same | |
| KR101342601B1 (en) | Negative active material, manufacturing method thereof, and lithium battery containing the material | |
| JP6508870B2 (en) | Composite active material for lithium secondary battery and method of manufacturing the same | |
| WO2016125819A1 (en) | Composite active material for lithium secondary cell and method for manufacturing same | |
| JP7452599B2 (en) | Composite active material for lithium secondary batteries | |
| JP6961948B2 (en) | Composite active material for silicon-based lithium secondary batteries and its manufacturing method | |
| JP6759583B2 (en) | Composite active material for lithium secondary battery and its manufacturing method, lithium secondary battery | |
| JP6961980B2 (en) | Composite active material for lithium secondary battery and its manufacturing method | |
| JP2017134937A (en) | Composite active material for lithium secondary battery and method of producing the same | |
| JP2002231225A (en) | Composite electrode material, its manufacturing method, lithium ion secondary electrode negative material using the same, and lithium ion secondary battery | |
| JP2017183113A (en) | Composite active material for lithium ion secondary battery, and method for manufacturing the same | |
| JP4542352B2 (en) | Negative electrode for lithium ion secondary battery and lithium ion secondary battery | |
| JP7009255B2 (en) | Binder and negative electrode material for negative electrode of lithium ion secondary battery | |
| JP2018170247A (en) | Composite active material for lithium secondary battery and manufacturing method thereof | |
| JPWO2019186828A1 (en) | Negative electrode material for lithium ion secondary battery, method for manufacturing negative electrode material for lithium ion secondary battery, negative electrode material slurry for lithium ion secondary battery, negative electrode material for lithium ion secondary battery, and lithium ion secondary battery | |
| KR20220148168A (en) | Composite particles for an electrochemical device, a method for manufacturing the same, and an electrode for an electrochemical device and an electrochemical device | |
| JP2021180124A (en) | Silicon or silicon alloy, composite active material for lithium secondary battery containing the same, and manufacturing method thereof | |
| WO2021193662A1 (en) | Composite active material for lithium secondary battery, electrode composition for lithium secondary battery, lithium secondary battery electrode, and method for manufacturing composite active material for lithium secondary battery | |
| JP2022190387A (en) | Composite active material for lithium secondary battery and manufacturing method for the same | |
| JP2021157996A (en) | Binder for lithium-ion secondary battery negative electrode and lithium-ion secondary battery negative electrode material containing the same | |
| JP2022551434A (en) | Spherical carbon-based negative electrode active material, manufacturing method thereof, negative electrode containing same, and lithium secondary battery | |
| CA3230663A1 (en) | Negative electrode active material, method for preparing the same, and negative electrode and secondary battery which include the same | |
| JP2017168376A (en) | Composite active material for lithium secondary battery and manufacturing method of the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20160121 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20181217 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20191007 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20191210 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20200124 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20200623 |