WO2017119410A1 - Lithium-copper composite oxide - Google Patents
Lithium-copper composite oxide Download PDFInfo
- Publication number
- WO2017119410A1 WO2017119410A1 PCT/JP2017/000017 JP2017000017W WO2017119410A1 WO 2017119410 A1 WO2017119410 A1 WO 2017119410A1 JP 2017000017 W JP2017000017 W JP 2017000017W WO 2017119410 A1 WO2017119410 A1 WO 2017119410A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- lithium
- copper
- composition formula
- positive electrode
- ion secondary
- Prior art date
Links
- OPHUWKNKFYBPDR-UHFFFAOYSA-N copper lithium Chemical compound [Li].[Cu] OPHUWKNKFYBPDR-UHFFFAOYSA-N 0.000 title claims abstract description 22
- 239000002131 composite material Substances 0.000 title claims abstract description 19
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 59
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 59
- 229910052732 germanium Inorganic materials 0.000 claims abstract description 26
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 25
- 239000000203 mixture Substances 0.000 claims description 103
- 229910052744 lithium Inorganic materials 0.000 claims description 51
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 47
- 239000010949 copper Substances 0.000 claims description 42
- 239000007774 positive electrode material Substances 0.000 claims description 36
- 229910052802 copper Inorganic materials 0.000 claims description 31
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 29
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 24
- 229910052760 oxygen Inorganic materials 0.000 claims description 24
- 239000001301 oxygen Substances 0.000 claims description 24
- 238000010438 heat treatment Methods 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 20
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 18
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 claims description 18
- 239000010703 silicon Substances 0.000 claims description 18
- 239000002245 particle Substances 0.000 claims description 17
- 229910052719 titanium Inorganic materials 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 150000001875 compounds Chemical class 0.000 abstract description 131
- 239000006182 cathode active material Substances 0.000 abstract 1
- 239000002994 raw material Substances 0.000 description 40
- 238000005259 measurement Methods 0.000 description 21
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 20
- 238000002156 mixing Methods 0.000 description 19
- -1 cobalt and nickel Chemical class 0.000 description 18
- 238000010304 firing Methods 0.000 description 18
- 239000013078 crystal Substances 0.000 description 17
- 238000002441 X-ray diffraction Methods 0.000 description 14
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 13
- 239000000463 material Substances 0.000 description 13
- 239000007773 negative electrode material Substances 0.000 description 12
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 10
- 229910045601 alloy Inorganic materials 0.000 description 10
- 239000000956 alloy Substances 0.000 description 10
- 229910052751 metal Inorganic materials 0.000 description 10
- 239000010936 titanium Substances 0.000 description 10
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 229910004298 SiO 2 Inorganic materials 0.000 description 8
- 239000000470 constituent Substances 0.000 description 8
- 238000003701 mechanical milling Methods 0.000 description 8
- 239000000047 product Substances 0.000 description 8
- 239000011230 binding agent Substances 0.000 description 7
- 239000008151 electrolyte solution Substances 0.000 description 7
- 229910052759 nickel Inorganic materials 0.000 description 7
- 239000000843 powder Substances 0.000 description 7
- 239000002904 solvent Substances 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 239000006230 acetylene black Substances 0.000 description 6
- 239000012298 atmosphere Substances 0.000 description 6
- 238000007599 discharging Methods 0.000 description 6
- 229910052742 iron Inorganic materials 0.000 description 6
- 239000011572 manganese Substances 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 5
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 5
- 239000002033 PVDF binder Substances 0.000 description 5
- 229910052782 aluminium Inorganic materials 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 5
- 239000003575 carbonaceous material Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000000634 powder X-ray diffraction Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 4
- 239000012752 auxiliary agent Substances 0.000 description 4
- 238000000975 co-precipitation Methods 0.000 description 4
- GEZOTWYUIKXWOA-UHFFFAOYSA-L copper;carbonate Chemical compound [Cu+2].[O-]C([O-])=O GEZOTWYUIKXWOA-UHFFFAOYSA-L 0.000 description 4
- AEJIMXVJZFYIHN-UHFFFAOYSA-N copper;dihydrate Chemical compound O.O.[Cu] AEJIMXVJZFYIHN-UHFFFAOYSA-N 0.000 description 4
- QYCVHILLJSYYBD-UHFFFAOYSA-L copper;oxalate Chemical compound [Cu+2].[O-]C(=O)C([O-])=O QYCVHILLJSYYBD-UHFFFAOYSA-L 0.000 description 4
- 239000003792 electrolyte Substances 0.000 description 4
- 239000011888 foil Substances 0.000 description 4
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium dioxide Chemical compound O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 description 4
- 238000003780 insertion Methods 0.000 description 4
- 230000037431 insertion Effects 0.000 description 4
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 4
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 4
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 238000003823 mortar mixing Methods 0.000 description 4
- 239000011255 nonaqueous electrolyte Substances 0.000 description 4
- 229910052814 silicon oxide Inorganic materials 0.000 description 4
- 239000002210 silicon-based material Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 229910052718 tin Inorganic materials 0.000 description 4
- 239000011135 tin Substances 0.000 description 4
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical class CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 3
- 229910000733 Li alloy Inorganic materials 0.000 description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical compound Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 description 3
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 description 3
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000001771 impaired effect Effects 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000001989 lithium alloy Substances 0.000 description 3
- AMXOYNBUYSYVKV-UHFFFAOYSA-M lithium bromide Chemical compound [Li+].[Br-] AMXOYNBUYSYVKV-UHFFFAOYSA-M 0.000 description 3
- HSZCZNFXUDYRKD-UHFFFAOYSA-M lithium iodide Chemical compound [Li+].[I-] HSZCZNFXUDYRKD-UHFFFAOYSA-M 0.000 description 3
- 239000012528 membrane Substances 0.000 description 3
- 229910052750 molybdenum Inorganic materials 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 230000002194 synthesizing effect Effects 0.000 description 3
- 229910052720 vanadium Inorganic materials 0.000 description 3
- ZXMGHDIOOHOAAE-UHFFFAOYSA-N 1,1,1-trifluoro-n-(trifluoromethylsulfonyl)methanesulfonamide Chemical compound FC(F)(F)S(=O)(=O)NS(=O)(=O)C(F)(F)F ZXMGHDIOOHOAAE-UHFFFAOYSA-N 0.000 description 2
- DHKHKXVYLBGOIT-UHFFFAOYSA-N 1,1-Diethoxyethane Chemical compound CCOC(C)OCC DHKHKXVYLBGOIT-UHFFFAOYSA-N 0.000 description 2
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 description 2
- VXEGSRKPIUDPQT-UHFFFAOYSA-N 4-[4-(4-methoxyphenyl)piperazin-1-yl]aniline Chemical compound C1=CC(OC)=CC=C1N1CCN(C=2C=CC(N)=CC=2)CC1 VXEGSRKPIUDPQT-UHFFFAOYSA-N 0.000 description 2
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 2
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- 229910005793 GeO 2 Inorganic materials 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 2
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 2
- 229910013553 LiNO Inorganic materials 0.000 description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 239000012300 argon atmosphere Substances 0.000 description 2
- 239000002134 carbon nanofiber Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 239000002482 conductive additive Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910000366 copper(II) sulfate Inorganic materials 0.000 description 2
- 238000003795 desorption Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- YNQRWVCLAIUHHI-UHFFFAOYSA-L dilithium;oxalate Chemical compound [Li+].[Li+].[O-]C(=O)C([O-])=O YNQRWVCLAIUHHI-UHFFFAOYSA-L 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 239000011737 fluorine Substances 0.000 description 2
- 229910052731 fluorine Inorganic materials 0.000 description 2
- GAEKPEKOJKCEMS-UHFFFAOYSA-N gamma-valerolactone Chemical compound CC1CCC(=O)O1 GAEKPEKOJKCEMS-UHFFFAOYSA-N 0.000 description 2
- 150000002291 germanium compounds Chemical class 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 229910003002 lithium salt Inorganic materials 0.000 description 2
- 159000000002 lithium salts Chemical class 0.000 description 2
- 239000011733 molybdenum Substances 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 229910052758 niobium Inorganic materials 0.000 description 2
- 239000010955 niobium Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229920000447 polyanionic polymer Polymers 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 230000009257 reactivity Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 229910052706 scandium Inorganic materials 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- 239000005049 silicon tetrachloride Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000007784 solid electrolyte Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000003115 supporting electrolyte Substances 0.000 description 2
- 238000001308 synthesis method Methods 0.000 description 2
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- DOYSIZKQWJYULQ-UHFFFAOYSA-N 1,1,2,2,2-pentafluoro-n-(1,1,2,2,2-pentafluoroethylsulfonyl)ethanesulfonamide Chemical compound FC(F)(F)C(F)(F)S(=O)(=O)NS(=O)(=O)C(F)(F)C(F)(F)F DOYSIZKQWJYULQ-UHFFFAOYSA-N 0.000 description 1
- LEEANUDEDHYDTG-UHFFFAOYSA-N 1,2-dimethoxypropane Chemical compound COCC(C)OC LEEANUDEDHYDTG-UHFFFAOYSA-N 0.000 description 1
- DURPTKYDGMDSBL-UHFFFAOYSA-N 1-butoxybutane Chemical compound CCCCOCCCC DURPTKYDGMDSBL-UHFFFAOYSA-N 0.000 description 1
- AVFZOVWCLRSYKC-UHFFFAOYSA-N 1-methylpyrrolidine Chemical compound CN1CCCC1 AVFZOVWCLRSYKC-UHFFFAOYSA-N 0.000 description 1
- JWUJQDFVADABEY-UHFFFAOYSA-N 2-methyltetrahydrofuran Chemical compound CC1CCCO1 JWUJQDFVADABEY-UHFFFAOYSA-N 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 229910000669 Chrome steel Inorganic materials 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910021591 Copper(I) chloride Inorganic materials 0.000 description 1
- ZAFNJMIOTHYJRJ-UHFFFAOYSA-N Diisopropyl ether Chemical compound CC(C)OC(C)C ZAFNJMIOTHYJRJ-UHFFFAOYSA-N 0.000 description 1
- 229910005839 GeS 2 Inorganic materials 0.000 description 1
- 239000007818 Grignard reagent Substances 0.000 description 1
- 229910019211 La0.51Li0.34TiO2.94 Inorganic materials 0.000 description 1
- 229910001228 Li[Ni1/3Co1/3Mn1/3]O2 (NCM 111) Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 238000003991 Rietveld refinement Methods 0.000 description 1
- 229910003691 SiBr Inorganic materials 0.000 description 1
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- DSRXQXXHDIAVJT-UHFFFAOYSA-N acetonitrile;n,n-dimethylformamide Chemical compound CC#N.CN(C)C=O DSRXQXXHDIAVJT-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910021486 amorphous silicon dioxide Inorganic materials 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000002041 carbon nanotube Substances 0.000 description 1
- 229910021393 carbon nanotube Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 229910000365 copper sulfate Inorganic materials 0.000 description 1
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 description 1
- LSXDOTMGLUJQCM-UHFFFAOYSA-M copper(i) iodide Chemical compound I[Cu] LSXDOTMGLUJQCM-UHFFFAOYSA-M 0.000 description 1
- OPQARKPSCNTWTJ-UHFFFAOYSA-L copper(ii) acetate Chemical compound [Cu+2].CC([O-])=O.CC([O-])=O OPQARKPSCNTWTJ-UHFFFAOYSA-L 0.000 description 1
- 229960003280 cupric chloride Drugs 0.000 description 1
- VNSVQJIXVXZDJF-UHFFFAOYSA-L dilithium;phthalate Chemical compound [Li+].[Li+].[O-]C(=O)C1=CC=CC=C1C([O-])=O VNSVQJIXVXZDJF-UHFFFAOYSA-L 0.000 description 1
- NKDDWNXOKDWJAK-UHFFFAOYSA-N dimethoxymethane Chemical compound COCOC NKDDWNXOKDWJAK-UHFFFAOYSA-N 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- KLKFAASOGCDTDT-UHFFFAOYSA-N ethoxymethoxyethane Chemical compound CCOCOCC KLKFAASOGCDTDT-UHFFFAOYSA-N 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- YIZVROFXIVWAAZ-UHFFFAOYSA-N germanium disulfide Chemical compound S=[Ge]=S YIZVROFXIVWAAZ-UHFFFAOYSA-N 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910021389 graphene Inorganic materials 0.000 description 1
- 150000004795 grignard reagents Chemical class 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- 238000002354 inductively-coupled plasma atomic emission spectroscopy Methods 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000010416 ion conductor Substances 0.000 description 1
- 239000002608 ionic liquid Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- XIXADJRWDQXREU-UHFFFAOYSA-M lithium acetate Chemical compound [Li+].CC([O-])=O XIXADJRWDQXREU-UHFFFAOYSA-M 0.000 description 1
- 229940031993 lithium benzoate Drugs 0.000 description 1
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 description 1
- JILPJDVXYVTZDQ-UHFFFAOYSA-N lithium methoxide Chemical compound [Li+].[O-]C JILPJDVXYVTZDQ-UHFFFAOYSA-N 0.000 description 1
- MHCFAGZWMAWTNR-UHFFFAOYSA-M lithium perchlorate Chemical compound [Li+].[O-]Cl(=O)(=O)=O MHCFAGZWMAWTNR-UHFFFAOYSA-M 0.000 description 1
- 229910001486 lithium perchlorate Inorganic materials 0.000 description 1
- INHCSSUBVCNVSK-UHFFFAOYSA-L lithium sulfate Inorganic materials [Li+].[Li+].[O-]S([O-])(=O)=O INHCSSUBVCNVSK-UHFFFAOYSA-L 0.000 description 1
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 description 1
- PSBOOKLOXQFNPZ-UHFFFAOYSA-M lithium;2-hydroxybenzoate Chemical compound [Li+].OC1=CC=CC=C1C([O-])=O PSBOOKLOXQFNPZ-UHFFFAOYSA-M 0.000 description 1
- LDJNSLOKTFFLSL-UHFFFAOYSA-M lithium;benzoate Chemical compound [Li+].[O-]C(=O)C1=CC=CC=C1 LDJNSLOKTFFLSL-UHFFFAOYSA-M 0.000 description 1
- AZVCGYPLLBEUNV-UHFFFAOYSA-N lithium;ethanolate Chemical compound [Li+].CC[O-] AZVCGYPLLBEUNV-UHFFFAOYSA-N 0.000 description 1
- AXMOZGKEVIBBCF-UHFFFAOYSA-M lithium;propanoate Chemical compound [Li+].CCC([O-])=O AXMOZGKEVIBBCF-UHFFFAOYSA-M 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920005672 polyolefin resin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- AIFMYMZGQVTROK-UHFFFAOYSA-N silicon tetrabromide Chemical compound Br[Si](Br)(Br)Br AIFMYMZGQVTROK-UHFFFAOYSA-N 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000012916 structural analysis Methods 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- RBTVSNLYYIMMKS-UHFFFAOYSA-N tert-butyl 3-aminoazetidine-1-carboxylate;hydrochloride Chemical compound Cl.CC(C)(C)OC(=O)N1CC(N)C1 RBTVSNLYYIMMKS-UHFFFAOYSA-N 0.000 description 1
- VJHDVMPJLLGYBL-UHFFFAOYSA-N tetrabromogermane Chemical compound Br[Ge](Br)(Br)Br VJHDVMPJLLGYBL-UHFFFAOYSA-N 0.000 description 1
- IEXRMSFAVATTJX-UHFFFAOYSA-N tetrachlorogermane Chemical compound Cl[Ge](Cl)(Cl)Cl IEXRMSFAVATTJX-UHFFFAOYSA-N 0.000 description 1
- PPMWWXLUCOODDK-UHFFFAOYSA-N tetrafluorogermane Chemical compound F[Ge](F)(F)F PPMWWXLUCOODDK-UHFFFAOYSA-N 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- CUDGTZJYMWAJFV-UHFFFAOYSA-N tetraiodogermane Chemical compound I[Ge](I)(I)I CUDGTZJYMWAJFV-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
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 1
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/32—Alkali metal silicates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G17/00—Compounds of germanium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G23/00—Compounds of titanium
- C01G23/04—Oxides; Hydroxides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
-
- 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
Definitions
- the present invention relates to a lithium copper based composite oxide.
- Lithium ion secondary batteries occupy the most important position among energy storage devices, and in recent years, their uses such as automobile batteries for plug-in hybrids are expanding.
- Non-patent Documents 1 and 2 positive electrode active materials such as LiCoO 2 and LiNi 1/3 Co 1/3 Mn 1/3 O 2 are mainly used for positive electrodes of lithium ion secondary batteries (Non-patent Documents 1 and 2).
- the positive electrode material containing these positive electrode active materials is expensive because it contains a large amount of rare metals such as cobalt and nickel, and is also a factor causing a heat generation accident and the like because of its strong combustion resistance. .
- Non-patent Document 3 As a positive electrode active material that can solve these problems, iron-based poly (oxo) that uses iron, which is an element abundant in nature, and has a strong polyanionic acid skeleton to significantly reduce the combustion resistance. ) Anionic materials, especially LiFePO 4, are attracting attention (Non-patent Document 3).
- the positive electrode material such as LiFePO 4 described above has a polyanion unit that does not participate in the charge / discharge reaction in the structure, it is more than a simple oxide positive electrode material such as LiCoO 2 having a theoretical capacity of 274 mAh / g.
- the tap density is inevitably lowered due to the formation of fine particles and the combination with carbon in practical use.
- the present invention has been made in view of such a current situation, and an object thereof is to provide a novel compound useful as a positive electrode active material for a lithium ion secondary battery.
- the present inventors have intensively studied to solve the above-described problems of the present invention. As a result, we succeeded in synthesizing lithium copper complex oxide having a specific composition. Furthermore, it has been found that the lithium copper-based composite oxide can insert and desorb lithium ions and exhibits a theoretical charge / discharge capacity that is high enough to be used as a positive electrode active material for a lithium ion secondary battery. The present inventors have completed the present invention by conducting further research based on these findings.
- composition formula (1) Li m Cu y X 1 O n
- X 1 represents Si or Ge.
- y represents 0.8 to 1.2.
- m represents 1.5 to 2.5.
- n represents 3.9 to 4.1.
- Item 2. The lithium copper-based composite oxide according to Item 1, having a monoclinic structure.
- Item 3. The lithium copper based composite oxide according to Item 1 or 2, wherein the average particle size is 0.1 to 100 ⁇ m.
- Item 5. The method according to Item 4, wherein the heating temperature is 600 ° C or higher.
- Item 6. Composition formula (2): Li m Cu y X 2 O n [In the composition formula (2), X 2 represents Si, Ti or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
- the positive electrode for lithium ion secondary batteries containing the positive electrode active material for lithium ion secondary batteries of said claim
- item 7 containing a conductive support agent.
- Item 9. A lithium ion secondary battery comprising the positive electrode for a lithium ion secondary battery according to Item 7 or 8.
- the lithium copper based composite oxide of the present invention can insert and desorb lithium ions, it can be used as a positive electrode active material for lithium ion secondary batteries.
- the lithium copper-based composite oxide of the present invention as a positive electrode active material, a lithium ion secondary battery exhibiting high charge / discharge capacity can be obtained.
- FIG. 2 is a diagram showing an X-ray diffraction pattern of Li 2 CuSiO 4 obtained in Example 1.
- Is a diagram showing the observation results by the scanning electron microscope of Example 1 Li 2 CuSiO 4 that the firing temperature was obtained when the 900 ° C. In (SEM).
- 6 is a diagram showing an X-ray diffraction pattern of Li 2 CuGeO 4 obtained in Example 2.
- FIG. 1 Is a diagram showing the observation results by the scanning electron microscope of Li 2 CuGeO 4 obtained when a 900 ° C. The calcination temperature in Example 2 (SEM). 3 is a cross-sectional view of a test cell used in Examples 3 and 4.
- FIG. It is a figure which shows the measurement result of the open circuit potential performed in Example 3. It is a figure which shows the measurement result (C / 20 rate) of the charging / discharging characteristic performed in Example 3.
- FIG. It is a figure which shows the measurement result (C / 50 rate) of the charging / discharging characteristic performed in Example 3.
- FIG. It is a figure which shows the charging / discharging result of only carbon and PVdF.
- Lithium copper-based composite oxide The lithium copper-based composite oxide of the present invention has a composition formula (1): Li m Cu y X 1 O n [In the composition formula (1), X 1 represents Si or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ] It is a compound represented by these. Hereinafter, the compound may be referred to as “a compound represented by the composition formula (1)”.
- X 1 is silicon (Si) or germanium (Ge).
- y is 0.8 to 1.2, and 0.8 to 1.0 is preferable from the viewpoint of increasing the capacity.
- m is 1.5 to 2.5, and preferably 1.75 to 2.25 from the viewpoint of easy insertion and desorption of lithium ions, capacity and potential.
- n is 3.9 to 4.1, and 3.95 to 4.05 is considered from the viewpoint of easy insertion and removal of lithium ions, capacity and potential. preferable.
- Specific examples of the compound represented by the composition formula (1) include Li 2 CuSiO 4 and Li 2 CuGeO 4 .
- Li 2 CuSiO 4 is preferable from the viewpoint of performance (particularly capacity improvement) when used as a positive electrode active material for a lithium ion secondary battery described later.
- the crystal structure of the compound represented by the composition formula (1) is preferably a monoclinic structure.
- the compound represented by the composition formula (1) preferably has a monoclinic crystal structure as the main phase.
- the abundance of the crystal structure as the main phase is not particularly limited, and is 80 mol% or more based on the whole compound represented by the compositional formula (1). Is preferable, and it is more preferable that it is 90 mol% or more.
- the compound represented by the composition formula (1) can be a material having a single-phase crystal structure, or a material having another crystal structure as long as the effects of the present invention are not impaired. You can also The crystal structure of the compound represented by the composition formula (1) can be confirmed by X-ray diffraction measurement.
- the compound represented by the composition formula (1) has peaks at various positions in the X-ray diffraction pattern by CuK ⁇ rays.
- Li 2 CuSiO 4 has a diffraction angle 2 ⁇ of 18.3 to 19.3 °, 26.3 to 27.0 °, 27.1 to 28.0 °, 28.8 to 29.6 °, 29. 9-30.5 °, 32.3-32.9 °, 35.5-36.7 °, 38.6-39.9 °, 40.8-42.0 °, 43.6-45.2 °, 45.7 to 46.8 °, 47.1 to 48.3 °, 48.5 to 49.8 °, 50.8 to 52.7 °, 53.7 to 55.2 °, 55.6 It preferably has peaks at -58.2 °, 62.3-63.4 °, 63.8-65.1 °, 68.6-71.0 °, and the like.
- Li 2 CuGeO 4 has a diffraction angle 2 ⁇ of 17.9 to 19.2 °, 24.9 to 27.0 °, 31.6 to 33.4 °, 35.0 to 39.2 °, 41.2 to 43.4 °, 49.2 to 51.5 °, 53.2 to 55.4 °, 56.9 to 58.7 °, 60.1 to 62.7 °, 63.7 to 65 It preferably has peaks at .2 °, 66.5 to 68.5 °, 69.9 to 71.7 °, 72.7 to 75.5 °, 76.9 to 78.4 °, and the like.
- the average particle size of the compound represented by the composition formula (1) is not particularly limited, and is preferably 0.1 to 100 ⁇ m, and preferably 0.1 to 50 ⁇ m from the viewpoint of shortening the Li + diffusion path. More preferably.
- the average particle diameter of the compound represented by the composition formula (1) can be confirmed by a scanning electron microscope (SEM).
- lithium, copper, silicon or germanium, and oxygen may be contained in the mixture in a predetermined ratio.
- lithium-containing compound, copper-containing compound, silicon-containing compound or germanium-containing compound, oxygen A containing compound or the like can be used.
- each compound such as a lithium-containing compound, a copper-containing compound, a silicon-containing compound, a germanium-containing compound, and an oxygen-containing compound is not particularly limited.
- One type of each element of lithium, copper, silicon, germanium, and oxygen It is also possible to use a mixture of four or more kinds of compounds including a compound containing two or more elements at the same time among lithium, copper, silicon or germanium, and oxygen as a part of the raw material. A mixture of less than four compounds can also be used.
- lithium, copper, silicon or germanium, and compounds containing no metal elements other than oxygen are preferable. Moreover, it is preferable that elements other than each element of lithium, copper, silicon or germanium, and oxygen contained in the raw material compound are separated or volatilized by the heat treatment described later.
- raw material compounds include the following compounds.
- lithium-containing compound examples include metallic lithium (Li); lithium bromide (LiBr); lithium oxalate (Li 2 C 2 O 4 ); lithium fluoride (LiF); lithium iodide (LiI); lithium sulfate (Li 2 ). SO 4 ); methoxy lithium (LiOCH 3 ); ethoxy lithium (LiOC 2 H 5 ); lithium hydroxide (LiOH); lithium nitrate (LiNO 3 ); lithium chloride (LiCl); lithium carbonate (Li 2 CO 3 ), etc. Can be mentioned.
- Examples of the copper-containing compound include metal copper (Cu); copper oxide (CuO); copper hydroxide (Cu (OH) 2 ); copper carbonate (CuCO 3 ); copper oxalate (CuC 2 O 4 ); copper sulfate (CuSO) 4 ); copper chloride (CuCl 2 ); copper iodide (CuI); copper acetate (Cu (CH 3 COO) 2 ) and the like.
- Silicon-containing compounds include silicon (Si); silicon oxide (SiO 2 ); tetraethoxysilane (SiOC 2 H 5 ); tetramethoxysilane (SiOCH 3 ); silicon tetrabromide (SiBr 4 ); silicon tetrachloride (SiCl) 4 ) and the like.
- Germanium compounds include germanium (Ge); germanium oxide (GeO 2 ); germanium tetrachloride (GeCl 4 ); germanium tetrabromide (GeBr 4 ); germanium tetraiodide (GeI 4 ); germanium tetrafluoride (GeF 4) ); Germanium disulfide (GeS 2 ) and the like.
- oxygen-containing compound examples include lithium hydroxide (LiOH); lithium carbonate (Li 2 CO 3 ); copper oxide (CuO); copper hydroxide (Cu (OH) 2 ); copper carbonate (CuCO 3 ); copper oxalate ( CuC 2 O 4 ); silicon oxide (SiO 2 ); germanium oxide (GeO 2 ) and the like.
- a hydrate can also be used for these raw material compounds.
- the raw material compound used in the production method of the present invention a commercially available product can be used, or it can be appropriately synthesized and used.
- the synthesis method in the case of synthesizing each raw material compound is not particularly limited, and can be carried out according to a known method.
- the shape of these raw material compounds is not particularly limited. From the viewpoint of ease of handling and the like, a powder form is preferable. From the viewpoint of reactivity, it is preferable that the particles are fine, and the average particle diameter is more preferably 1 ⁇ m or less (preferably about 10 to 500 nm, particularly preferably about 60 to 80 nm). . In addition, the average particle diameter of a raw material compound can be measured with a scanning electron microscope (SEM).
- a mixture containing lithium, copper, silicon or germanium, and oxygen can be obtained by mixing necessary materials among the above-described raw material compounds.
- the mixing ratio of each raw material compound is not particularly limited, and it is preferable to mix so that the composition of the compound represented by the above composition formula (1) which is the final product is obtained.
- the mixing ratio of the raw material compounds is preferably such that the ratio of each element contained in the raw material compound is the same as the ratio of each element in the compound represented by the composition formula (1) to be generated.
- the method for preparing a mixture containing lithium, copper, silicon or germanium, and oxygen is not particularly limited, and a method capable of uniformly mixing each raw material compound can be employed.
- a method capable of uniformly mixing each raw material compound can be employed.
- mortar mixing, mechanical milling treatment, coprecipitation method, a method of mixing after each raw material compound is dispersed in a solvent, a method of dispersing each raw material compound at once in a solvent and mixing, etc. can be adopted. .
- a mixture can be obtained by a simple method by employing mortar mixing, and a uniform mixture can be obtained by employing a coprecipitation method.
- a ball mill for example, a vibration mill, a turbo mill, a disk mill, or the like can be used as the mechanical milling device, and a ball mill is preferable.
- a mechanical milling process it is preferable to perform mixing and a heating simultaneously.
- the atmosphere during mixing and heating is not particularly limited.
- an inert gas atmosphere such as argon or nitrogen, a hydrogen gas atmosphere, or the like can be employed.
- mixing and heating may be performed under reduced pressure such as vacuum.
- the heating temperature is not particularly limited, and the crystallinity of the compound represented by the above composition formula (1) and the electrode obtained From the viewpoint of further improving the characteristics (capacity and potential), it is preferably 600 ° C. or higher, more preferably 700 ° C. or higher, further preferably 800 ° C. or higher, and particularly preferably 900 ° C. or higher. preferable.
- the upper limit of the heating temperature is not particularly limited as long as the temperature is such that the compound represented by the composition formula (1) can be easily produced (for example, about 1500 ° C.).
- the heating temperature is preferably 600 to 1500 ° C., more preferably 700 to 1500 ° C., further preferably 800 to 1500 ° C., and particularly preferably 900 to 1500 ° C. .
- Positive electrode active material for lithium ion secondary battery Since the compound represented by the above composition formula (1) has the above composition and crystal structure, it can insert and desorb lithium ions. It can be used as a positive electrode active material. Therefore, this invention includes the positive electrode active material for lithium ion secondary batteries containing the compound represented by the said composition formula (1).
- composition formula (2) Li m Cu y X 2 O n
- X 2 represents Si, Ti or Ge.
- y represents 0.8 to 1.2.
- m represents 1.5 to 2.5.
- n represents 3.9 to 4.1.
- Lithium copper-based composite oxides can also be used as positive electrode active materials for lithium ion secondary batteries because lithium ions can be inserted and removed.
- the lithium copper-based composite oxide represented by the composition formula (2) may be referred to as “a compound represented by the composition formula (2)”. Therefore, this invention includes the positive electrode active material for lithium ion secondary batteries containing the compound represented by the said composition formula (2).
- a positive electrode active material for a lithium ion secondary battery containing a compound represented by the composition formula (1) and a positive electrode active material for a lithium ion secondary battery containing a compound represented by the composition formula (2) May be collectively described as “the positive electrode active material for a lithium ion secondary battery of the present invention”.
- X 2 is silicon (Si), titanium (Ti), or germanium (Ge).
- y is 0.8 to 1.2, and 0.8 to 1.0 is preferable from the viewpoint of increasing the capacity.
- m is 1.5 to 2.5, and preferably 1.75 to 2.25 from the viewpoint of easy insertion and desorption of lithium ions, capacity and potential.
- n is 3.9 to 4.1, and is preferably 3.95 to 4.05 from the viewpoint of easy insertion and removal of lithium ions, capacity and potential.
- Li 2 CuSiO 4 Li 2 CuTiO 4 , and Li 2 CuGeO 4 .
- Li 2 CuSiO 4 is preferable from the viewpoint of performance (particularly capacity improvement) when used as a positive electrode active material for a lithium ion secondary battery.
- the crystal structure of the compound represented by the composition formula (2) is preferably a monoclinic structure.
- the compound represented by the composition formula (2) preferably has a monoclinic crystal structure as the main phase.
- the amount of the crystal structure that is the main phase is not particularly limited, and is 80 mol% or more based on the whole compound represented by the composition formula (2). Is preferable, and it is more preferable that it is 90 mol% or more.
- the compound represented by the composition formula (2) can be a material having a single-phase crystal structure, or a material having another crystal structure as long as the effects of the present invention are not impaired. You can also.
- the crystal structure of the compound represented by the composition formula (2) can be confirmed by X-ray diffraction measurement.
- the compound represented by the composition formula (2) has peaks at various positions in the X-ray diffraction pattern by CuK ⁇ rays.
- Li 2 CuSiO 4 has a diffraction angle 2 ⁇ of 18.3 to 19.3 °, 26.3 to 27.0 °, 27.1 to 28.0 °, 28.8 to 29.6 °, 29. 9-30.5 °, 32.3-32.9 °, 35.5-36.7 °, 38.6-39.9 °, 40.8-42.0 °, 43.6-45.2 °, 45.7 to 46.8 °, 47.1 to 48.3 °, 48.5 to 49.8 °, 50.8 to 52.7 °, 53.7 to 55.2 °, 55.6 It preferably has peaks at -58.2 °, 62.3-63.4 °, 63.8-65.1 °, 68.6-71.0 °, and the like.
- Li 2 CuGeO 4 has a diffraction angle 2 ⁇ of 17.9 to 19.2 °, 24.9 to 27.0 °, 31.6 to 33.4 °, 35.0 to 39.2 °, 41.2 to 43.4 °, 49.2 to 51.5 °, 53.2 to 55.4 °, 56.9 to 58.7 °, 60.1 to 62.7 °, 63.7 to 65 It preferably has peaks at .2 °, 66.5 to 68.5 °, 69.9 to 71.7 °, 72.7 to 75.5 °, 76.9 to 78.4 °, and the like.
- the average particle size of the compound represented by the composition formula (2) is not particularly limited, and is preferably 0.1 to 100 ⁇ m, and preferably 0.1 to 50 ⁇ m from the viewpoint of shortening the Li + diffusion path. It is more preferable.
- the average particle diameter of the compound represented by the composition formula (2) can be confirmed by a scanning electron microscope (SEM).
- Method for producing a compound represented by the formula (2) include lithium, copper, and the X 2, the step of heating a mixture comprising oxygen.
- Lithium-containing compounds, copper-containing compounds, X 2 containing compound is not particularly limited about the kind of each compound such as oxygen-containing compounds, lithium, copper, four or comprises one by one each element of X 2, and oxygen It is also possible to use a mixture of more compounds, and a compound containing two or more elements of lithium, copper, X 2 and oxygen at the same time is used as a part of the raw material, and less than four kinds A mixture of compounds can also be used.
- these raw material compounds compounds containing no metal elements other than lithium, copper, X 2 , and oxygen (particularly rare metal elements) are preferable. Moreover, it is preferable that elements other than each element of lithium, copper, X 2 , and oxygen contained in the raw material compound are separated or volatilized by a heat treatment described later.
- raw material compounds include the following compounds.
- lithium-containing compound examples include lithium oxalate (Li 2 C 2 O 4 ); lithium hydroxide (LiOH); lithium nitrate (LiNO 3 ); lithium chloride (LiCl); lithium carbonate (Li 2 CO 3 ) and the like. .
- Examples of the copper-containing compound include metal copper (Cu); copper oxide (CuO); copper hydroxide (Cu (OH) 2 ); copper carbonate (CuCO 3 ); copper oxalate (CuC 2 O 4 ); cupric chloride (CuCl 2 ); cupric sulfate (CuSO 4 ); cupric nitrate (Cu (NO 3 ) 2 ); cupric sulfate (CuSO 4 ) and the like.
- titanium-containing compound examples include titanium tetrachloride (TiCl 4 ) and titanium hydroxide (Ti (OH) 2 ).
- silicon-containing compound examples include silicon (Si); silicon oxide (SiO 2 ) and the like.
- germanium compound examples include germanium (Ge); germanium oxide (GeO 2 ) and the like.
- oxygen-containing compound examples include lithium hydroxide (LiOH); lithium carbonate (Li 2 CO 3 ); copper oxide (CuO); copper hydroxide (Cu (OH) 2 ); copper carbonate (CuCO 3 ); copper oxalate ( CuC 2 O 4 ); silicon oxide (SiO 2 ); titanium oxide (TiO 2 ); titanium hydroxide (Ti (OH) 2 ); germanium oxide (GeO 2 ) and the like.
- a hydrate can also be used for these raw material compounds.
- the raw material compound used in the method for producing the compound represented by the composition formula (2) a commercially available product can be used, or it can be synthesized and used as appropriate.
- the synthesis method in the case of synthesizing each raw material compound is not particularly limited, and can be carried out according to a known method.
- the shape of these raw material compounds is not particularly limited. From the viewpoint of ease of handling and the like, a powder form is preferable. Further, from the viewpoint of reactivity, it is preferable that the particles are fine, and it is more preferable that the particles have a mean particle size of 1 ⁇ m or less (preferably about 10 to 100 nm, particularly preferably about 60 to 80 nm). . In addition, the average particle diameter of a raw material compound can be measured with a scanning electron microscope (SEM).
- Lithium, and copper, and X 2 mixture comprising oxygen can be obtained by mixing the necessary materials of the feed compounds described above.
- the mixing ratio of each raw material compound is not particularly limited, and it is preferable to mix so as to have a composition possessed by the compound represented by the composition formula (2) which is the final product.
- the mixing ratio of the raw material compounds is preferably such that the ratio of each element contained in the raw material compound is the same as the ratio of each element in the compound represented by the composition formula (2) to be generated.
- Lithium, and copper, and X 2 not particularly limited as methods for preparing the mixture comprising oxygen, it is possible to employ a method of each raw material compound can be uniformly mixed.
- a method of each raw material compound can be uniformly mixed.
- mortar mixing, mechanical milling treatment, coprecipitation method, a method of mixing after each raw material compound is dispersed in a solvent, a method of dispersing each raw material compound at once in a solvent and mixing, etc. can be adopted. .
- a mixture can be obtained by a simple method by employing mortar mixing, and a uniform mixture can be obtained by employing a coprecipitation method.
- a ball mill for example, a vibration mill, a turbo mill, a disk mill, or the like can be used as the mechanical milling device, and a ball mill is preferable.
- a mechanical milling process it is preferable to perform mixing and a heating simultaneously.
- the atmosphere during mixing and heating is not particularly limited.
- an inert gas atmosphere such as argon or nitrogen, a hydrogen gas atmosphere, or the like can be employed.
- mixing and heating may be performed under reduced pressure such as vacuum.
- Lithium, and copper, and X 2 when heating a mixture comprising oxygen, crystallinity and electrode characteristics of heating is not particularly limited as temperature, the compound represented by the obtained above composition formula (2) From the viewpoint of further improving (capacity and potential), it is preferably 600 ° C. or higher, more preferably 700 ° C. or higher, further preferably 800 ° C. or higher, and particularly preferably 900 ° C. or higher. .
- the upper limit of the heating temperature is not particularly limited as long as the temperature is such that the compound represented by the composition formula (2) can be easily produced (for example, about 1500 ° C.).
- the heating temperature is preferably 600 to 1500 ° C., more preferably 700 to 1500 ° C., further preferably 800 to 1500 ° C., and particularly preferably 900 to 1500 ° C. .
- the positive electrode active material for a lithium ion secondary battery of the present invention includes a compound represented by the above composition formula (1) or a compound represented by the composition formula (2) and a carbon material (for example, carbon black such as acetylene black) And a material) may form a composite.
- a carbon material for example, carbon black such as acetylene black
- the content of the carbon material is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and particularly preferably 5 to 15% by mass in the positive electrode active material for a lithium ion secondary battery of the present invention. is there.
- the positive electrode active material for a lithium ion secondary battery of the present invention contains the compound represented by the above composition formula (1) or the compound represented by the composition formula (2).
- the positive electrode active material for a lithium ion secondary battery of the present invention may be composed of only the compound represented by the composition formula (1) or the compound represented by the composition formula (2), or the composition described above.
- an unavoidable impurity may be included. Examples of such inevitable impurities include the raw material compounds described above.
- the content of inevitable impurities is 10 mol% or less, preferably 5 mol% or less, more preferably 2 mol% or less, as long as the effects of the present invention are not impaired.
- Positive electrode for lithium ion secondary battery and lithium ion secondary battery are the compound represented by the above composition formula (1) or the composition formula (2).
- the basic structure is the known positive electrode for non-aqueous electrolyte (non-aqueous) lithium ion secondary battery and non-aqueous electrolyte (non-aqueous) lithium ion, except that the compound represented by A configuration similar to that of the secondary battery can be employed.
- the positive electrode, the negative electrode, and the separator can be disposed in the battery container such that the positive electrode and the negative electrode are separated from each other by the separator.
- the lithium ion secondary battery of the present invention can be manufactured by, for example, sealing the battery container after filling the battery container with the nonaqueous electrolytic solution.
- the lithium ion secondary battery of the present invention may be a lithium secondary battery.
- “lithium ion secondary battery” means a secondary battery using lithium ions as carrier ions
- “lithium secondary battery” means a secondary that uses lithium metal or a lithium alloy as a negative electrode active material. Means battery.
- the positive electrode for a lithium ion secondary battery of the present invention has a structure in which a positive electrode active material containing a compound represented by the above composition formula (1) or a compound represented by the composition formula (2) is supported on a positive electrode current collector. Can be adopted.
- a positive electrode material containing the compound represented by the above-described composition formula (1) or the compound represented by the composition formula (2), a conductive auxiliary agent, and a binder as necessary is used as a positive electrode current collector. It can be manufactured by coating.
- the conductive aid for example, carbon materials such as acetylene black, ketjen black, carbon nanotube, vapor grown carbon fiber, carbon nanofiber, graphite, coke, etc. can be used.
- the shape of the conductive auxiliary agent is not particularly limited, and for example, a powder form can be adopted.
- fluorine resins such as polyvinylidene fluoride resin and polytetrafluoroethylene can be used.
- the content of various components in the positive electrode material is not particularly limited, and can be appropriately determined from a wide range.
- the compound represented by the composition formula (1) or the compound represented by the composition formula (2) is 50 to 95% by volume (particularly 70 to 90% by volume), and the conductive assistant is 2.5 to 25%. It is preferable to contain volume% (especially 5 to 15 volume%) and 2.5 to 25 volume% (particularly 5 to 15 volume%) of a binder.
- Examples of the material constituting the positive electrode current collector include aluminum, platinum, molybdenum, and stainless steel.
- Examples of the shape of the positive electrode current collector include a porous body, a foil, a plate, and a mesh made of fibers.
- the amount of the positive electrode material applied to the positive electrode current collector is not particularly limited, and is preferably determined appropriately according to the use of the lithium ion secondary battery.
- Examples of the negative electrode active material constituting the negative electrode include lithium metal; silicon; silicon-containing acrylate compound; lithium alloy; M 1 M 2 2 O 4 (M 1 : Co, Ni, Mn, Sn, etc., M 2 : Mn, Ternary or quaternary oxides represented by Fe, Zn, etc .; M 3 3 O 4 (M 3 : Fe, Co, Ni, Mn, etc.), M 4 2 O 3 (M 4 : Fe, Co, Ni) , Mn, etc.), MnV 2 O 6 , M 5 O 2 (M 5 : Sn, Ti etc.), M 6 O (M 6 : Fe, Co, Ni, Mn, Sn, Cu etc.) Oxides; graphite, hard carbon, soft carbon, graphene; carbon materials described above; organic systems such as Li 2 C 6 H 4 O 4 , Li 2 C 8 H 4 O 4 , Li 2 C 16 H 8 O 4 Compounds and the like.
- lithium alloys include alloys containing lithium and aluminum as constituent elements, alloys containing lithium and zinc as constituent elements, alloys containing lithium and lead as constituent elements, alloys containing lithium and manganese as constituent elements, lithium and bismuth. Alloys containing lithium and nickel as constituent elements, alloys containing lithium and antimony as constituent elements, alloys containing lithium and tin as constituent elements, alloys containing lithium and indium as constituent elements; metal (scandium) , Titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, and the like) and carbon containing MXene alloy, M 7 x BC 3 alloy (M 7 : Sc, Ti, V, Cr, Zr, Nb, Mo, Hf Ta, etc.) quaternary layered carbide or nitride compounds such like.
- the negative electrode can be composed of a negative electrode active material, and a configuration in which a negative electrode material containing a negative electrode active material, a conductive additive, and a binder as required is supported on the negative electrode current collector is adopted. You can also. When adopting a configuration in which the negative electrode material is supported on the negative electrode current collector, a negative electrode mixture containing a negative electrode active material, a conductive additive, and a binder as necessary is applied to the negative electrode current collector. Can be manufactured.
- the negative electrode is composed of a negative electrode active material
- the above negative electrode active material has a shape suitable for an electrode (plate shape, etc.) It can be obtained by molding.
- the types of the conductive auxiliary agent and the binder, and the negative electrode active material, the conductive auxiliary agent, and the binder content are those of the positive electrode described above. Can be applied.
- the material constituting the negative electrode current collector include aluminum, copper, nickel, and stainless steel.
- Examples of the shape of the negative electrode current collector include a porous body, a foil, a plate, and a mesh made of fibers. In addition, it is preferable to determine suitably the application quantity of the negative electrode material with respect to a negative electrode collector according to the use etc. of a lithium ion secondary battery.
- the separator is not limited as long as it is made of a material that can separate the positive electrode and the negative electrode in the battery and can hold the electrolyte solution to ensure the ionic conductivity between the positive electrode and the negative electrode.
- polyolefin resin such as polyethylene, polypropylene, polyimide, polyvinyl alcohol, terminal aminated polyethylene oxide
- fluorine resin such as polytetrafluoroethylene
- acrylic resin nylon
- aromatic aramid inorganic glass
- Materials in the form of a membrane, nonwoven fabric, woven fabric, etc. can be used.
- the non-aqueous electrolyte is preferably an electrolyte containing lithium ions.
- an electrolytic solution include a lithium salt solution, an ionic liquid composed of an inorganic material containing lithium, and the like.
- lithium salt examples include lithium halides such as lithium chloride, lithium bromide and lithium iodide; lithium inorganic salts such as lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate and lithium hexafluoroarsenate
- lithium halides such as lithium chloride, lithium bromide and lithium iodide
- lithium inorganic salts such as lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate and lithium hexafluoroarsenate
- Lithium organic salt compounds such as bis (trifluoromethylsulfonyl) imide lithium, bis (perfluoroethanesulfonyl) imide lithium, lithium benzoate, lithium salicylate, lithium phthalate, lithium acetate, lithium propionate, Grignard reagent, etc. Can be mentioned.
- the solvent examples include carbonate compounds such as propylene carbonate, ethylene carbonate, dimethol carbonate, ethylmethyl carbonate, and diethyl carbonate; lactone compounds such as ⁇ -butyrolactone and ⁇ -valerolactone; tetrahydrofuran, 2-methyltetrahydrofuran, diethyl Ether compounds such as ether, diisopropyl ether, dibutyl ether, methoxymethane, glyme, dimethoxyethane, dimethoxymethane, diethoxymethane, diethoxyethane, propylene glycol dimethyl ether; acetonitrile; N, N-dimethylformamide; N-propyl-N- And methylpyrrolidinium bis (trifluoromethanesulfonyl) imide.
- carbonate compounds such as propylene carbonate, ethylene carbonate, dimethol carbonate, ethylmethyl carbonate, and diethyl
- a solid electrolyte can be used instead of the non-aqueous electrolyte.
- the solid electrolyte include lithium ion conductors such as Li 10 GeP 2 S 12 , Li 7 P 3 S 11 , Li 7 La 3 Zr 2 O 12 , La 0.51 Li 0.34 TiO 2.94, and the like. Enumerated.
- the lithium ion secondary battery of the present invention since the compound represented by the composition formula (1) or the compound represented by the composition formula (2) is used, the oxidation-reduction reaction (charge / discharge reaction) is performed. A higher potential and energy density can be ensured, and safety (polyanion skeleton) and practicality are excellent. Therefore, the lithium ion secondary battery of the present invention can be suitably used, for example, for devices that are required to be downsized and high performance.
- Example 1 A synthetic material powder of Li 2 CuSiO 4, Li 2 CO 3 ( manufactured by Rare Metallic Co.; 99.9% (3N)), CuO ( Kojundo Chemical Laboratory Co., Ltd.; 99.99% (4N )), And precipitated amorphous SiO 2 (manufactured by Kanto Chemical Co .; 3N).
- Li 2 CO 3 , CuO, and SiO 2 were weighed so that the ratio of lithium: copper: silicon (molar ratio) was 2: 1: 1, and placed in a chrome steel container together with zirconia balls (15 mm ⁇ ⁇ 10 pieces). The mixture was pulverized and mixed for 24 hours at 400 rpm in a planetary ball mill (manufactured by Fritsch, trade name: P-6).
- the recovered powder was pelleted by hand pressing and calcined at 600 ° C., 700 ° C., 800 ° C., 900 ° C., or 1000 ° C. for 1 hour under an argon stream.
- the temperature rising rate was 400 ° C./h.
- the cooling rate was set to 100 ° C./h up to 300 ° C., and thereafter, the mixture was naturally cooled to room temperature.
- Each obtained product Li 2 CuSiO 4
- XRD powder X-ray diffraction
- XRD powder X-ray diffraction
- an X-ray diffraction measurement device manufactured by Rigaku Corporation, trade name: RINT2200
- the X-ray source was CuK ⁇ monochromatized with a monochromator.
- Data were collected under the measurement conditions of a tube voltage of 5 kV and a tube current of 300 mA. At this time, the scanning speed was set so that the intensity was about 10,000 counts.
- the sample used for measurement was sufficiently pulverized so that the particles were uniform.
- Rietveld analysis was performed for the structural analysis, and JANA-2006 was used as the analysis program.
- FIG. 1 confirms that when the firing temperature is 800 ° C. or higher, a plurality of main peaks are observed at least at 2 ⁇ values of 15 to 70 °. Further, since the peak observed at 2 ⁇ value of 15 to 70 ° is stronger as the firing temperature is higher, it was found that a higher firing temperature is preferable.
- the plurality of main peaks confirmed at 2 ⁇ values of 15 to 70 ° correspond to single-phase Li 2 CuSiO 4 , and thus single-phase Li 2 CuSiO 4 is obtained as a product. I understood. Further, from FIG. 2, CuO which is a raw material compound, and from the fact that peaks derived from Li 2 SiO 3 generated from Li 2 CO 3 and SiO 2 which is a raw material compound is not verified, the single-phase Li 2 It was found that CuSiO 4 was obtained.
- the Li 2 CuSiO 4 crystals obtained when the firing temperature was set to 900 ° C. had a diffraction angle expressed by 2 ⁇ of 18.31 to 19 in an X-ray diffraction pattern by powder X-ray diffraction. .24 °, 26.39 to 26.96 °, 27.22 to 27.39 °, 28.90 to 29.59 °, 38.65 to 39.82 °, 40.88 to 41.92 °, 43 63 to 45.12 °, 45.72 to 46.70 °, 47.21 to 48.23 °, 48.56 to 49.71 °, 50.87 to 52.69 °, 53.81 to 55.
- Li 2 CuSiO 4 obtained when the firing temperature was 900 ° C. was observed with a scanning electron microscope (SEM). The results are shown in FIG. In FIG. 3, the scale bar indicates 11.7 ⁇ m. From FIG. 3, it was found that Li 2 CuSiO 4 having a particle diameter of about 3 to 10 ⁇ m was obtained.
- Example 2 Li 2 CO 3 (manufactured by Rare Metallic; 99.9% (3N)), CuO (manufactured by High-Purity Chemical Laboratories ); 99.99% (4N) as a synthetic raw material powder of Li 2 CuGeO 4 )), And GeO 2 (manufactured by Kanto Chemical Co .; 99.99% (4N)).
- Li 2 CO 3 , CuO, and GeO 2 were weighed so that the ratio of lithium: copper: germanium (molar ratio) was 2: 1: 1, placed in a chromium steel container together with zirconia balls (15 mm ⁇ ⁇ 10), and acetone
- the mixture was pulverized and mixed for 24 hours at 400 rpm in a planetary ball mill (manufactured by Fritsch, trade name: P-6).
- the collected powder was pelleted by hand and baked at 700 ° C., 800 ° C., or 900 ° C. for 1 hour under an argon stream. At this time, the temperature rising rate was 400 ° C./h.
- the Li 2 CuSiO 4 crystals obtained when the firing temperature was set to 700 ° C. had a diffraction angle of 17.94 to 19 expressed by 2 ⁇ in the X-ray diffraction pattern by powder X-ray diffraction. .15 °, 24.96 to 26.91 °, 31.65 to 33.32 °, 35.07 to 39.17 °, 41.30 to 43.39 °, 49.29 to 51.44 °, 53 24 to 55.30 °, 56.92 to 58.63 °, 60.16 to 62.63 °, 63.79 to 65.19 °, 66.57 to 68.44 °, 69.92 to 71.
- Li 2 CuGeO 4 obtained when the firing temperature was 900 ° C. was observed with a scanning electron microscope (SEM). The results are shown in FIG. In FIG. 5, the scale bar indicates 27.0 ⁇ m. From FIG. 5, it was found that Li 2 CuGeO 4 having a particle diameter of about 1 to 50 ⁇ m was obtained.
- Example 3 Li 2 to make measurements discharge measurements of the charge and discharge characteristics of CuSiO 4, Li 2 CuSiO 4 were obtained when the firing temperature 900 ° C.
- PVDF polyvinylidene fluoride
- AB Acetylene black
- the first embodiment polyvinylidene fluoride (PVDF), and Acetylene black (AB) was mixed in an agate mortar so that the volume ratio was 85: 7.5: 7.5, and the resulting slurry was applied onto an aluminum foil (thickness 20 ⁇ m) as a positive electrode current collector, This was punched into a circle with a diameter of 8 mm to obtain a positive electrode. Further, in order to prevent the sample from being peeled off from the positive electrode current collector, it was pressure-bonded at 30 to 40 mPa.
- the electrolytic solution is an electrolytic solution (manufactured by Kishida Chemical Co., Ltd.) in which LiPF 6 is dissolved at a concentration of 1 mol / dm 3 as a supporting electrolyte in a solvent in which ethylene carbonate (EC) and diethyl carbonate (DEC) are mixed at a volume ratio of 1: 2. used.
- the battery was produced in Globe Books under an argon atmosphere because of the use of metallic lithium and the cause of increased resistance when water was mixed in the electrolyte.
- a CR2032-type coin cell shown in FIG. 6 was used as the cell.
- the potential in a state where no current was applied to the electrode ie, open circuit potential
- the constant current charge / discharge measurement was started from charging by using a voltage switch, setting a C / 20 rate or C / 50 rate, a current of 10 mA / g, an upper limit voltage of 4.8 V, and a lower limit voltage of 1.5 V.
- the charge / discharge measurement was performed in a state where the cell was placed in a 55 ° C. constant temperature bath.
- FIG. 7 shows the measurement results of the open circuit potential
- the C rate means a current density necessary for charging / discharging the theoretical capacity from the electrode active material in one hour.
- Li 2 CuSiO 4 was 220 mAh / g (capacity corresponding to about 70% of the theoretical capacity) at the C / 50 rate. Also from this, Li 2 CuSiO 4 is expected as a high capacity material.
- a positive electrode was produced in the same manner as described above except that Li 2 CuSiO 4 was not used, and a charge / discharge test was performed at a C / 20 rate under the same conditions as described above. The results are shown in FIG.
- Example 4 Li 2 to make measurements discharge measurements of the charge and discharge characteristics of CuGeO 4, the example Li 2 CuGeO 4 were obtained when the firing temperature 900 ° C. at 2, polyvinylidene fluoride (PVDF), and Acetylene black (AB) was mixed in an agate mortar so that the volume ratio was 85: 7.5: 7.5, and the resulting slurry was applied onto an aluminum foil (thickness 20 ⁇ m) as a positive electrode current collector, This was punched into a circle with a diameter of 8 mm to obtain a positive electrode. Further, in order to prevent the sample from being peeled off from the positive electrode current collector, it was pressure-bonded at 30 to 40 mPa.
- PVDF polyvinylidene fluoride
- AB Acetylene black
- the electrolytic solution is an electrolytic solution (manufactured by Kishida Chemical Co., Ltd.) in which LiPF 6 is dissolved at a concentration of 1 mol / dm 3 as a supporting electrolyte in a solvent in which ethylene carbonate (EC) and diethyl carbonate (DEC) are mixed at a volume ratio of 1: 2. used.
- the battery was produced in Globe Books under an argon atmosphere because of the use of metallic lithium and the cause of increased resistance when water was mixed in the electrolyte.
- a CR2032-type coin cell shown in FIG. 6 was used as the cell.
- the potential in a state where no current was applied to the electrode ie, open circuit potential
- the constant current charge / discharge measurement was started from charging by using a voltage switch, setting a C / 50 rate, a current of 10 mA / g, an upper limit voltage of 4.8 V, and a lower limit voltage of 1.5 V.
- the charge / discharge measurement was performed in a state where the cell was placed in a 55 ° C. constant temperature bath.
- FIG. 11 shows the measurement result of the open circuit potential
- FIG. 12 shows the measurement result of the charge / discharge characteristics (relationship between each cycle and the discharge capacity).
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Geology (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Abstract
Provided is a novel compound that is useful as a cathode active material for a lithium ion secondary battery. A lithium-copper composite oxide represented by formula (1): LimCuyX1On. In formula (1), X1 represents Si or Ge, y is 0.8-1.2, m is 1.5-2.5 and n is 3.9-4.1.
Description
本発明は、リチウム銅系複合酸化物に関する。
The present invention relates to a lithium copper based composite oxide.
リチウムイオン二次電池は、エネルギー貯蔵デバイスの中で最も重要な位置を占めるものであり、近年では、プラグインハイブリッド用自動車電池等、その用途が拡大しつつある。
Lithium ion secondary batteries occupy the most important position among energy storage devices, and in recent years, their uses such as automobile batteries for plug-in hybrids are expanding.
リチウムイオン二次電池の正極に関し、現在、LiCoO2、LiNi1/3Co1/3Mn1/3O2などの正極活物質が主流となっている(非特許文献1及び2)。しかしながら、これらの正極活物質を含む正極材料には、コバルト、ニッケルなどの希少金属が大量に含まれているため高価であり、さらに、助燃性も強いため発熱事故等を引き起こす要因となっている。
Currently, positive electrode active materials such as LiCoO 2 and LiNi 1/3 Co 1/3 Mn 1/3 O 2 are mainly used for positive electrodes of lithium ion secondary batteries (Non-patent Documents 1 and 2). However, the positive electrode material containing these positive electrode active materials is expensive because it contains a large amount of rare metals such as cobalt and nickel, and is also a factor causing a heat generation accident and the like because of its strong combustion resistance. .
そこで、現在では、このような問題を解決可能な正極活物質として、自然界に豊富に存在する元素である鉄を利用し、強固なポリアニオン酸骨格により助燃性を大幅に抑制した鉄系ポリ(オキソ)アニオン材料、特にLiFePO4が注目されている(非特許文献3)。
Therefore, as a positive electrode active material that can solve these problems, iron-based poly (oxo) that uses iron, which is an element abundant in nature, and has a strong polyanionic acid skeleton to significantly reduce the combustion resistance. ) Anionic materials, especially LiFePO 4, are attracting attention (Non-patent Document 3).
しかしながら、上記したLiFePO4等の正極材料は、構造中に充放電反応に関与しないポリアニオンユニットを有していることから、理論容量が274mAh/gのLiCoO2などの単純酸化物系正極材料よりも低く、また、実用化に際しては微粒子化、カーボンとの複合化などを行うため、タップ密度も必然的に低下する。
However, since the positive electrode material such as LiFePO 4 described above has a polyanion unit that does not participate in the charge / discharge reaction in the structure, it is more than a simple oxide positive electrode material such as LiCoO 2 having a theoretical capacity of 274 mAh / g. In addition, the tap density is inevitably lowered due to the formation of fine particles and the combination with carbon in practical use.
本発明は、このような現状に鑑みてなされたものであり、リチウムイオン二次電池用正極活物質として有用な新規化合物を提供することを目的とする。
The present invention has been made in view of such a current situation, and an object thereof is to provide a novel compound useful as a positive electrode active material for a lithium ion secondary battery.
本発明者らは、上記した本発明の課題を解決すべく鋭意検討を重ねてきた。その結果、特定の組成を有するリチウム銅系複合酸化物の合成に成功した。さらに、当該リチウム銅系複合酸化物は、リチウムイオンの挿入及び脱離が可能であり、リチウムイオン二次電池用正極活物質として使用できる程度に高い理論充放電容量を示すことを見出した。本発明者らは、これらの知見に基づいてさらなる研究を重ねることにより本発明を完成させるに至った。
The present inventors have intensively studied to solve the above-described problems of the present invention. As a result, we succeeded in synthesizing lithium copper complex oxide having a specific composition. Furthermore, it has been found that the lithium copper-based composite oxide can insert and desorb lithium ions and exhibits a theoretical charge / discharge capacity that is high enough to be used as a positive electrode active material for a lithium ion secondary battery. The present inventors have completed the present invention by conducting further research based on these findings.
即ち、本発明は、代表的には以下の項に記載の主題を包含する。
項1.
組成式(1):
LimCuyX1On
[組成式(1)中、X1はSi又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表されるリチウム銅系複合酸化物。
項2.
単斜晶構造を有する、上記項1に記載のリチウム銅系複合酸化物。
項3.
平均粒子径が0.1~100μmである、上記項1又は2に記載のリチウム銅系複合酸化物。
項4.
リチウムと、銅と、ケイ素又はゲルマニウムと、酸素とを含む混合物を加熱する工程を含む、上記項1~3のいずれかに記載のリチウム銅系複合酸化物の製造方法。
項5.
加熱温度が600℃以上である、上記項4に記載の方法。
項6.
組成式(2):
LimCuyX2On
[組成式(2)中、X2はSi、Ti又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表されるリチウム銅系複合酸化物を含む、リチウムイオン二次電池用正極活物質。
項7.
上記項6に記載のリチウムイオン二次電池用正極活物質を含む、リチウムイオン二次電池用正極。
項8.
さらに、導電助剤を含む、上記項7に記載のリチウムイオン二次電池用正極。
項9.
上記項7又は8に記載のリチウムイオン二次電池用正極を含む、リチウムイオン二次電池。 That is, the present invention typically includes the subject matters described in the following sections.
Item 1.
Composition formula (1):
Li m Cu y X 1 O n
[In the composition formula (1), X 1 represents Si or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
Lithium copper-based composite oxide represented by
Item 2.
Item 2. The lithium copper-based composite oxide according toItem 1, having a monoclinic structure.
Item 3.
Item 3. The lithium copper based composite oxide according toItem 1 or 2, wherein the average particle size is 0.1 to 100 μm.
Item 4.
Item 4. The method for producing a lithium-copper composite oxide according to any one of Items 1 to 3, further comprising a step of heating a mixture containing lithium, copper, silicon or germanium, and oxygen.
Item 5.
Item 5. The method according to Item 4, wherein the heating temperature is 600 ° C or higher.
Item 6.
Composition formula (2):
Li m Cu y X 2 O n
[In the composition formula (2), X 2 represents Si, Ti or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
The positive electrode active material for lithium ion secondary batteries containing the lithium copper type complex oxide represented by these.
Item 7.
The positive electrode for lithium ion secondary batteries containing the positive electrode active material for lithium ion secondary batteries of said claim |item 6.
Item 8.
Furthermore, the positive electrode for lithium ion secondary batteries of the said claim |item 7 containing a conductive support agent.
Item 9.
A lithium ion secondary battery comprising the positive electrode for a lithium ion secondary battery according toItem 7 or 8.
項1.
組成式(1):
LimCuyX1On
[組成式(1)中、X1はSi又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表されるリチウム銅系複合酸化物。
項2.
単斜晶構造を有する、上記項1に記載のリチウム銅系複合酸化物。
項3.
平均粒子径が0.1~100μmである、上記項1又は2に記載のリチウム銅系複合酸化物。
項4.
リチウムと、銅と、ケイ素又はゲルマニウムと、酸素とを含む混合物を加熱する工程を含む、上記項1~3のいずれかに記載のリチウム銅系複合酸化物の製造方法。
項5.
加熱温度が600℃以上である、上記項4に記載の方法。
項6.
組成式(2):
LimCuyX2On
[組成式(2)中、X2はSi、Ti又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表されるリチウム銅系複合酸化物を含む、リチウムイオン二次電池用正極活物質。
項7.
上記項6に記載のリチウムイオン二次電池用正極活物質を含む、リチウムイオン二次電池用正極。
項8.
さらに、導電助剤を含む、上記項7に記載のリチウムイオン二次電池用正極。
項9.
上記項7又は8に記載のリチウムイオン二次電池用正極を含む、リチウムイオン二次電池。 That is, the present invention typically includes the subject matters described in the following sections.
Composition formula (1):
Li m Cu y X 1 O n
[In the composition formula (1), X 1 represents Si or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
Lithium copper-based composite oxide represented by
Item 2.
Item 2. The lithium copper-based composite oxide according to
Item 3.
Item 3. The lithium copper based composite oxide according to
Composition formula (2):
Li m Cu y X 2 O n
[In the composition formula (2), X 2 represents Si, Ti or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
The positive electrode active material for lithium ion secondary batteries containing the lithium copper type complex oxide represented by these.
The positive electrode for lithium ion secondary batteries containing the positive electrode active material for lithium ion secondary batteries of said claim |
Item 8.
Furthermore, the positive electrode for lithium ion secondary batteries of the said claim |
Item 9.
A lithium ion secondary battery comprising the positive electrode for a lithium ion secondary battery according to
本発明のリチウム銅系複合酸化物は、リチウムイオンを挿入及び脱離することができるため、リチウムイオン二次電池用正極活物質として使用することができる。特に、本発明のリチウム銅系複合酸化物を正極活物質として用いることにより、高い充放電容量を発揮するリチウムイオン二次電池とすることができる。
Since the lithium copper based composite oxide of the present invention can insert and desorb lithium ions, it can be used as a positive electrode active material for lithium ion secondary batteries. In particular, by using the lithium copper-based composite oxide of the present invention as a positive electrode active material, a lithium ion secondary battery exhibiting high charge / discharge capacity can be obtained.
以下、本発明について詳細に説明する。なお、本明細書において、数値範囲を示す場合、当該数値範囲はいずれも両端の数値を含む。
Hereinafter, the present invention will be described in detail. In the present specification, when a numerical range is indicated, the numerical range includes both numerical values.
1.リチウム銅系複合酸化物
本発明のリチウム銅系複合酸化物は、組成式(1):
LimCuyX1On
[組成式(1)中、X1はSi又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表される化合物である。なお、以下において、当該化合物を「組成式(1)で表される化合物」と記載する場合がある。 1. Lithium copper-based composite oxide The lithium copper-based composite oxide of the present invention has a composition formula (1):
Li m Cu y X 1 O n
[In the composition formula (1), X 1 represents Si or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
It is a compound represented by these. Hereinafter, the compound may be referred to as “a compound represented by the composition formula (1)”.
本発明のリチウム銅系複合酸化物は、組成式(1):
LimCuyX1On
[組成式(1)中、X1はSi又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表される化合物である。なお、以下において、当該化合物を「組成式(1)で表される化合物」と記載する場合がある。 1. Lithium copper-based composite oxide The lithium copper-based composite oxide of the present invention has a composition formula (1):
Li m Cu y X 1 O n
[In the composition formula (1), X 1 represents Si or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
It is a compound represented by these. Hereinafter, the compound may be referred to as “a compound represented by the composition formula (1)”.
上記組成式(1)において、X1は、ケイ素(Si)又はゲルマニウム(Ge)である。
In the composition formula (1), X 1 is silicon (Si) or germanium (Ge).
上記組成式(1)において、yは0.8~1.2であり、高容量化の観点からは0.8~1.0が好ましい。
In the composition formula (1), y is 0.8 to 1.2, and 0.8 to 1.0 is preferable from the viewpoint of increasing the capacity.
上記組成式(1)において、mは1.5~2.5であり、リチウムイオンの挿入及び脱離のし易さ、並びに容量及び電位の観点からは1.75~2.25が好ましい。また、上記一般式(1)において、nは3.9~4.1であり、リチウムイオンの挿入及び脱離のし易さ、並びに容量及び電位の観点からは3.95~4.05が好ましい。
In the composition formula (1), m is 1.5 to 2.5, and preferably 1.75 to 2.25 from the viewpoint of easy insertion and desorption of lithium ions, capacity and potential. In the above general formula (1), n is 3.9 to 4.1, and 3.95 to 4.05 is considered from the viewpoint of easy insertion and removal of lithium ions, capacity and potential. preferable.
上記組成式(1)で表される化合物としては、具体的には、Li2CuSiO4、Li2CuGeO4などが挙げられる。中でも、後述するリチウムイオン二次電池用正極活物質として用いる場合、性能(特に、容量向上)の観点からは、Li2CuSiO4が好ましい。
Specific examples of the compound represented by the composition formula (1) include Li 2 CuSiO 4 and Li 2 CuGeO 4 . Among these, Li 2 CuSiO 4 is preferable from the viewpoint of performance (particularly capacity improvement) when used as a positive electrode active material for a lithium ion secondary battery described later.
上記組成式(1)で表される化合物の結晶構造は、単斜晶構造であることが好ましい。特に、上記組成式(1)で表される化合物は、単斜晶構造が主相であることが好ましい。上記組成式(1)で表される化合物において、主相である結晶構造の存在量は特に限定的ではなく、上記組成式(1)で表される化合物全体を基準として80mol%以上であることが好ましく、90mol%以上であることがより好ましい。このため、上記組成式(1)で表される化合物は、単相の結晶構造からなる材料とすることもできるし、本発明の効果を損なわない範囲で、他の結晶構造を有する材料とすることもできる。なお、上記組成式(1)で表される化合物の結晶構造は、X線回折測定により確認することができる。
The crystal structure of the compound represented by the composition formula (1) is preferably a monoclinic structure. In particular, the compound represented by the composition formula (1) preferably has a monoclinic crystal structure as the main phase. In the compound represented by the compositional formula (1), the abundance of the crystal structure as the main phase is not particularly limited, and is 80 mol% or more based on the whole compound represented by the compositional formula (1). Is preferable, and it is more preferable that it is 90 mol% or more. For this reason, the compound represented by the composition formula (1) can be a material having a single-phase crystal structure, or a material having another crystal structure as long as the effects of the present invention are not impaired. You can also The crystal structure of the compound represented by the composition formula (1) can be confirmed by X-ray diffraction measurement.
上記組成式(1)で表される化合物は、CuKα線によるX線回折図において、種々の位置にピークを有する。
The compound represented by the composition formula (1) has peaks at various positions in the X-ray diffraction pattern by CuKα rays.
例えば、Li2CuSiO4は、回折角2θが18.3~19.3°、26.3~27.0°、27.1~28.0°、28.8~29.6°、29.9~30.5°、32.3~32.9°、35.5~36.7°、38.6~39.9°、40.8~42.0°、43.6~45.2°、45.7~46.8°、47.1~48.3°、48.5~49.8°、50.8~52.7°、53.7~55.2°、55.6~58.2°、62.3~63.4°、63.8~65.1°、及び68.6~71.0°等にピークを有することが好ましい。
For example, Li 2 CuSiO 4 has a diffraction angle 2θ of 18.3 to 19.3 °, 26.3 to 27.0 °, 27.1 to 28.0 °, 28.8 to 29.6 °, 29. 9-30.5 °, 32.3-32.9 °, 35.5-36.7 °, 38.6-39.9 °, 40.8-42.0 °, 43.6-45.2 °, 45.7 to 46.8 °, 47.1 to 48.3 °, 48.5 to 49.8 °, 50.8 to 52.7 °, 53.7 to 55.2 °, 55.6 It preferably has peaks at -58.2 °, 62.3-63.4 °, 63.8-65.1 °, 68.6-71.0 °, and the like.
また、例えば、Li2CuGeO4は、回折角2θが17.9~19.2°、24.9~27.0°、31.6~33.4°、35.0~39.2°、41.2~43.4°、49.2~51.5°、53.2~55.4°、56.9~58.7°、60.1~62.7°、63.7~65.2°、66.5~68.5°、69.9~71.7°、72.7~75.5°、及び76.9~78.4°等にピークを有することが好ましい。
Also, for example, Li 2 CuGeO 4 has a diffraction angle 2θ of 17.9 to 19.2 °, 24.9 to 27.0 °, 31.6 to 33.4 °, 35.0 to 39.2 °, 41.2 to 43.4 °, 49.2 to 51.5 °, 53.2 to 55.4 °, 56.9 to 58.7 °, 60.1 to 62.7 °, 63.7 to 65 It preferably has peaks at .2 °, 66.5 to 68.5 °, 69.9 to 71.7 °, 72.7 to 75.5 °, 76.9 to 78.4 °, and the like.
上記組成式(1)で表される化合物の平均粒子径は特に限定的ではなく、Li+拡散経路の短縮化の観点から、0.1~100μmであることが好ましく、0.1~50μmであることがより好ましい。なお、上記組成式(1)で表される化合物の平均粒子径は、走査型電子顕微鏡(SEM)により確認することができる。
The average particle size of the compound represented by the composition formula (1) is not particularly limited, and is preferably 0.1 to 100 μm, and preferably 0.1 to 50 μm from the viewpoint of shortening the Li + diffusion path. More preferably. In addition, the average particle diameter of the compound represented by the composition formula (1) can be confirmed by a scanning electron microscope (SEM).
2.リチウム銅系複合酸化物の製造方法
上記組成式(1)で表される化合物の製造方法において、リチウムと、銅と、ケイ素又はゲルマニウムと、酸素とを含む混合物を得るための原料化合物としては、最終的に混合物中にリチウムと、銅と、ケイ素又はゲルマニウムと、酸素とが所定の比率で含まれていればよく、例えば、リチウム含有化合物、銅含有化合物、ケイ素含有化合物又はゲルマニウム含有化合物、酸素含有化合物等を用いることができる。 2. Method for Producing Lithium Copper Complex Oxide In the method for producing a compound represented by the above composition formula (1), as a raw material compound for obtaining a mixture containing lithium, copper, silicon or germanium, and oxygen, Finally, lithium, copper, silicon or germanium, and oxygen may be contained in the mixture in a predetermined ratio. For example, lithium-containing compound, copper-containing compound, silicon-containing compound or germanium-containing compound, oxygen A containing compound or the like can be used.
上記組成式(1)で表される化合物の製造方法において、リチウムと、銅と、ケイ素又はゲルマニウムと、酸素とを含む混合物を得るための原料化合物としては、最終的に混合物中にリチウムと、銅と、ケイ素又はゲルマニウムと、酸素とが所定の比率で含まれていればよく、例えば、リチウム含有化合物、銅含有化合物、ケイ素含有化合物又はゲルマニウム含有化合物、酸素含有化合物等を用いることができる。 2. Method for Producing Lithium Copper Complex Oxide In the method for producing a compound represented by the above composition formula (1), as a raw material compound for obtaining a mixture containing lithium, copper, silicon or germanium, and oxygen, Finally, lithium, copper, silicon or germanium, and oxygen may be contained in the mixture in a predetermined ratio. For example, lithium-containing compound, copper-containing compound, silicon-containing compound or germanium-containing compound, oxygen A containing compound or the like can be used.
リチウム含有化合物、銅含有化合物、ケイ素含有化合物、ゲルマニウム含有化合物、酸素含有化合物等の各化合物の種類については特に限定的ではなく、リチウム、銅、ケイ素又はゲルマニウム、及び酸素の各元素を1種類ずつ含む4種類又はそれ以上の化合物を混合して用いることもでき、また、リチウム、銅、ケイ素又はゲルマニウム、及び酸素のうち、2種類又はそれ以上の元素を同時に含む化合物を原料の一部として用い、4種類未満の化合物を混合して用いることもできる。
The type of each compound such as a lithium-containing compound, a copper-containing compound, a silicon-containing compound, a germanium-containing compound, and an oxygen-containing compound is not particularly limited. One type of each element of lithium, copper, silicon, germanium, and oxygen It is also possible to use a mixture of four or more kinds of compounds including a compound containing two or more elements at the same time among lithium, copper, silicon or germanium, and oxygen as a part of the raw material. A mixture of less than four compounds can also be used.
これらの原料化合物としては、リチウム、銅、ケイ素又はゲルマニウム、及び酸素以外の金属元素(特に、希少金属元素)を含まない化合物が好ましい。また、原料化合物中に含まれるリチウム、銅、ケイ素又はゲルマニウム、及び酸素の各元素以外の元素については、後述する加熱処理により離脱又は揮発していくものであることが好ましい。
As these raw material compounds, lithium, copper, silicon or germanium, and compounds containing no metal elements other than oxygen (particularly rare metal elements) are preferable. Moreover, it is preferable that elements other than each element of lithium, copper, silicon or germanium, and oxygen contained in the raw material compound are separated or volatilized by the heat treatment described later.
このような原料化合物の具体例としては以下の化合物が挙げられる。
Specific examples of such raw material compounds include the following compounds.
リチウム含有化合物としては、金属リチウム(Li);臭化リチウム(LiBr);シュウ酸リチウム(Li2C2O4);フッ化リチウム(LiF);ヨウ化リチウム(LiI);硫酸リチウム(Li2SO4);メトキシリチウム(LiOCH3);エトキシリチウム(LiOC2H5);水酸化リチウム(LiOH);硝酸リチウム(LiNO3);塩化リチウム(LiCl);炭酸リチウム(Li2CO3)などが挙げられる。
Examples of the lithium-containing compound include metallic lithium (Li); lithium bromide (LiBr); lithium oxalate (Li 2 C 2 O 4 ); lithium fluoride (LiF); lithium iodide (LiI); lithium sulfate (Li 2 ). SO 4 ); methoxy lithium (LiOCH 3 ); ethoxy lithium (LiOC 2 H 5 ); lithium hydroxide (LiOH); lithium nitrate (LiNO 3 ); lithium chloride (LiCl); lithium carbonate (Li 2 CO 3 ), etc. Can be mentioned.
銅含有化合物としては、金属銅(Cu);酸化銅(CuO);水酸化銅(Cu(OH)2);炭酸銅(CuCO3);シュウ酸銅(CuC2O4);硫酸銅(CuSO4);塩化銅(CuCl2);ヨウ化銅(CuI);酢酸銅(Cu(CH3COO)2)等が挙げられる。
Examples of the copper-containing compound include metal copper (Cu); copper oxide (CuO); copper hydroxide (Cu (OH) 2 ); copper carbonate (CuCO 3 ); copper oxalate (CuC 2 O 4 ); copper sulfate (CuSO) 4 ); copper chloride (CuCl 2 ); copper iodide (CuI); copper acetate (Cu (CH 3 COO) 2 ) and the like.
ケイ素含有化合物としては、ケイ素(Si);酸化ケイ素(SiO2);テトラエトキシシラン(SiOC2H5);テトラメトキシシラン(SiOCH3);四臭化ケイ素(SiBr4);四塩化ケイ素(SiCl4)等が挙げられる。
Silicon-containing compounds include silicon (Si); silicon oxide (SiO 2 ); tetraethoxysilane (SiOC 2 H 5 ); tetramethoxysilane (SiOCH 3 ); silicon tetrabromide (SiBr 4 ); silicon tetrachloride (SiCl) 4 ) and the like.
ゲルマニウム化合物としては、ゲルマニウム(Ge);酸化ゲルマニウム(GeO2);四塩化ゲルマニウム(GeCl4);四臭化ゲルマニウム(GeBr4);四ヨウ化ゲルマニウム(GeI4);四フッ化ゲルマニウム(GeF4);二硫化ゲルマニウム(GeS2)等が挙げられる。
Germanium compounds include germanium (Ge); germanium oxide (GeO 2 ); germanium tetrachloride (GeCl 4 ); germanium tetrabromide (GeBr 4 ); germanium tetraiodide (GeI 4 ); germanium tetrafluoride (GeF 4) ); Germanium disulfide (GeS 2 ) and the like.
酸素含有化合物としては、水酸化リチウム(LiOH);炭酸リチウム(Li2CO3);酸化銅(CuO);水酸化銅(Cu(OH)2);炭酸銅(CuCO3);シュウ酸銅(CuC2O4);酸化ケイ素(SiO2);酸化ゲルマニウム(GeO2)等が挙げられる。
Examples of the oxygen-containing compound include lithium hydroxide (LiOH); lithium carbonate (Li 2 CO 3 ); copper oxide (CuO); copper hydroxide (Cu (OH) 2 ); copper carbonate (CuCO 3 ); copper oxalate ( CuC 2 O 4 ); silicon oxide (SiO 2 ); germanium oxide (GeO 2 ) and the like.
なお、これらの原料化合物は水和物を使用することもできる。
In addition, a hydrate can also be used for these raw material compounds.
また、本発明の製造方法において使用する原料化合物は、市販品を用いることもできるし、適宜合成して使用することもできる。各原料化合物を合成する場合の合成方法は特に限定的ではなく、公知の方法に従って行うことができる。
In addition, as the raw material compound used in the production method of the present invention, a commercially available product can be used, or it can be appropriately synthesized and used. The synthesis method in the case of synthesizing each raw material compound is not particularly limited, and can be carried out according to a known method.
これら原料化合物の形状については特に制限されない。取り扱い易さ等の観点からは、粉末状であることが好ましい。また、反応性の観点からは、粒子が微細である方が好ましく、平均粒子径が1μm以下(好ましくは、10~500nm程度、特に好ましくは60~80nm程度)の粉末状であることがより好ましい。なお、原料化合物の平均粒子径は、走査型電子顕微鏡(SEM)により測定することができる。
The shape of these raw material compounds is not particularly limited. From the viewpoint of ease of handling and the like, a powder form is preferable. From the viewpoint of reactivity, it is preferable that the particles are fine, and the average particle diameter is more preferably 1 μm or less (preferably about 10 to 500 nm, particularly preferably about 60 to 80 nm). . In addition, the average particle diameter of a raw material compound can be measured with a scanning electron microscope (SEM).
リチウムと、銅と、ケイ素又はゲルマニウムと、酸素とを含む混合物は、上記した原料化合物のうち必要な材料を混合することにより得ることができる。
A mixture containing lithium, copper, silicon or germanium, and oxygen can be obtained by mixing necessary materials among the above-described raw material compounds.
各原料化合物の混合割合については特に限定的ではなく、最終生成物である上記組成式(1)で表される化合物が有する組成となるように混合することが好ましい。原料化合物の混合割合は、原料化合物に含まれる各元素の比率が、生成される上記組成式(1)で表される化合物中の各元素の比率と同一となるようにすることが好ましい。
The mixing ratio of each raw material compound is not particularly limited, and it is preferable to mix so that the composition of the compound represented by the above composition formula (1) which is the final product is obtained. The mixing ratio of the raw material compounds is preferably such that the ratio of each element contained in the raw material compound is the same as the ratio of each element in the compound represented by the composition formula (1) to be generated.
リチウムと、銅と、ケイ素又はゲルマニウムと、酸素とを含む混合物を調製するための方法としては特に限定的ではなく、各原料化合物を均一に混合できる方法を採用することができる。例えば、乳鉢混合、メカニカルミリング処理、共沈法、各原料化合物を溶媒中に分散させた後に混合する方法、各原料化合物を溶媒中で一度に分散させて混合させる方法などを採用することができる。これらの中でも、乳鉢混合を採用することにより簡便な方法によって混合物を得ることができ、また、共沈法を採用することにより均一な混合物を得ることができる。
The method for preparing a mixture containing lithium, copper, silicon or germanium, and oxygen is not particularly limited, and a method capable of uniformly mixing each raw material compound can be employed. For example, mortar mixing, mechanical milling treatment, coprecipitation method, a method of mixing after each raw material compound is dispersed in a solvent, a method of dispersing each raw material compound at once in a solvent and mixing, etc. can be adopted. . Among these, a mixture can be obtained by a simple method by employing mortar mixing, and a uniform mixture can be obtained by employing a coprecipitation method.
また、混合手段としてメカニカルミリング処理を行う場合、メカニカルミリング装置としては、例えば、ボールミル、振動ミル、ターボミル、ディスクミル等を用いることができ、中でもボールミルが好ましい。また、メカニカルミリング処理を行う場合には、混合と加熱とを同時に行うことが好ましい。
Further, when performing mechanical milling as the mixing means, for example, a ball mill, a vibration mill, a turbo mill, a disk mill, or the like can be used as the mechanical milling device, and a ball mill is preferable. Moreover, when performing a mechanical milling process, it is preferable to perform mixing and a heating simultaneously.
混合時及び加熱時の雰囲気は特に限定的ではなく、例えば、アルゴン、窒素等の不活性ガス雰囲気、水素ガス雰囲気などを採用することができる。また、真空等の減圧下で混合及び加熱を行ってもよい。
The atmosphere during mixing and heating is not particularly limited. For example, an inert gas atmosphere such as argon or nitrogen, a hydrogen gas atmosphere, or the like can be employed. Further, mixing and heating may be performed under reduced pressure such as vacuum.
リチウムと、銅と、ケイ素又はゲルマニウムと、酸素とを含む混合物を加熱する際に、加熱温度としては特に限定的ではなく、得られる上記組成式(1)で表される化合物の結晶性及び電極特性(容量及び電位)をより向上させる観点から、600℃以上とすることが好ましく、700℃以上とすることがより好ましく、800℃以上とすることがさらに好ましく、900℃以上とすることが特に好ましい。なお、加熱温度の上限については特に限定的ではなく、上記組成式(1)で表される化合物の製造を容易に行うことができる程度の温度(例えば、1500℃程度)であればよい。換言すると、加熱温度としては、600~1500℃とすることが好ましく、700~1500℃とすることがより好ましく、800~1500℃とすることがさらに好ましく、900~1500℃とすることが特に好ましい。
When heating a mixture containing lithium, copper, silicon or germanium and oxygen, the heating temperature is not particularly limited, and the crystallinity of the compound represented by the above composition formula (1) and the electrode obtained From the viewpoint of further improving the characteristics (capacity and potential), it is preferably 600 ° C. or higher, more preferably 700 ° C. or higher, further preferably 800 ° C. or higher, and particularly preferably 900 ° C. or higher. preferable. The upper limit of the heating temperature is not particularly limited as long as the temperature is such that the compound represented by the composition formula (1) can be easily produced (for example, about 1500 ° C.). In other words, the heating temperature is preferably 600 to 1500 ° C., more preferably 700 to 1500 ° C., further preferably 800 to 1500 ° C., and particularly preferably 900 to 1500 ° C. .
3.リチウムイオン二次電池用正極活物質
上記組成式(1)で表される化合物は、上記した組成及び結晶構造を有しているため、リチウムイオンを挿入及び脱離できることから、リチウムイオン二次電池用正極活物質として用いることができる。従って、本発明は、上記組成式(1)で表される化合物を含むリチウムイオン二次電池用正極活物質を包含する。 3. Positive electrode active material for lithium ion secondary battery Since the compound represented by the above composition formula (1) has the above composition and crystal structure, it can insert and desorb lithium ions. It can be used as a positive electrode active material. Therefore, this invention includes the positive electrode active material for lithium ion secondary batteries containing the compound represented by the said composition formula (1).
上記組成式(1)で表される化合物は、上記した組成及び結晶構造を有しているため、リチウムイオンを挿入及び脱離できることから、リチウムイオン二次電池用正極活物質として用いることができる。従って、本発明は、上記組成式(1)で表される化合物を含むリチウムイオン二次電池用正極活物質を包含する。 3. Positive electrode active material for lithium ion secondary battery Since the compound represented by the above composition formula (1) has the above composition and crystal structure, it can insert and desorb lithium ions. It can be used as a positive electrode active material. Therefore, this invention includes the positive electrode active material for lithium ion secondary batteries containing the compound represented by the said composition formula (1).
また、組成式(1)で表される化合物又のみならず、組成式(2):
LimCuyX2On
[組成式(2)中、X2はSi、Ti又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表されるリチウム銅系複合酸化物も、リチウムイオンを挿入及び脱離できることから、リチウムイオン二次電池用正極活物質として用いることができる。なお、以下において、上記組成式(2)で表されるリチウム銅系複合酸化物を「上記組成式(2)で表される化合物」と記載する場合がある。従って、本発明は、上記組成式(2)で表される化合物を含むリチウムイオン二次電池用正極活物質を包含する。 Further, not only the compound represented by the composition formula (1) but also the composition formula (2):
Li m Cu y X 2 O n
[In the composition formula (2), X 2 represents Si, Ti or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
Lithium copper-based composite oxides can also be used as positive electrode active materials for lithium ion secondary batteries because lithium ions can be inserted and removed. Hereinafter, the lithium copper-based composite oxide represented by the composition formula (2) may be referred to as “a compound represented by the composition formula (2)”. Therefore, this invention includes the positive electrode active material for lithium ion secondary batteries containing the compound represented by the said composition formula (2).
LimCuyX2On
[組成式(2)中、X2はSi、Ti又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表されるリチウム銅系複合酸化物も、リチウムイオンを挿入及び脱離できることから、リチウムイオン二次電池用正極活物質として用いることができる。なお、以下において、上記組成式(2)で表されるリチウム銅系複合酸化物を「上記組成式(2)で表される化合物」と記載する場合がある。従って、本発明は、上記組成式(2)で表される化合物を含むリチウムイオン二次電池用正極活物質を包含する。 Further, not only the compound represented by the composition formula (1) but also the composition formula (2):
Li m Cu y X 2 O n
[In the composition formula (2), X 2 represents Si, Ti or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
Lithium copper-based composite oxides can also be used as positive electrode active materials for lithium ion secondary batteries because lithium ions can be inserted and removed. Hereinafter, the lithium copper-based composite oxide represented by the composition formula (2) may be referred to as “a compound represented by the composition formula (2)”. Therefore, this invention includes the positive electrode active material for lithium ion secondary batteries containing the compound represented by the said composition formula (2).
なお、以下において、上記組成式(1)で表される化合物を含むリチウムイオン二次電池用正極活物質及び上記組成式(2)で表される化合物を含むリチウムイオン二次電池用正極活物質をまとめて、「本発明のリチウムイオン二次電池用正極活物質」と記載する場合がある。
In the following, a positive electrode active material for a lithium ion secondary battery containing a compound represented by the composition formula (1) and a positive electrode active material for a lithium ion secondary battery containing a compound represented by the composition formula (2) May be collectively described as “the positive electrode active material for a lithium ion secondary battery of the present invention”.
上記組成式(2)において、X2は、ケイ素(Si)、チタン(Ti)又はゲルマニウム(Ge)である。
In the composition formula (2), X 2 is silicon (Si), titanium (Ti), or germanium (Ge).
上記組成式(2)において、yは0.8~1.2であり、高容量化の観点からは0.8~1.0が好ましい。
In the composition formula (2), y is 0.8 to 1.2, and 0.8 to 1.0 is preferable from the viewpoint of increasing the capacity.
上記組成式(2)において、mは1.5~2.5であり、リチウムイオンの挿入及び脱離のし易さ、並びに容量及び電位の観点からは1.75~2.25が好ましい。nは3.9~4.1であり、リチウムイオンの挿入及び脱離のし易さ、並びに容量及び電位の観点からは3.95~4.05が好ましい。
In the above composition formula (2), m is 1.5 to 2.5, and preferably 1.75 to 2.25 from the viewpoint of easy insertion and desorption of lithium ions, capacity and potential. n is 3.9 to 4.1, and is preferably 3.95 to 4.05 from the viewpoint of easy insertion and removal of lithium ions, capacity and potential.
上記組成式(2)で表される化合物としては、具体的には、Li2CuSiO4、Li2CuTiO4、Li2CuGeO4などが挙げられる。中でも、リチウムイオン二次電池用正極活物質として用いた場合の性能(特に容量向上)の観点からは、Li2CuSiO4が好ましい。
Specific examples of the compound represented by the composition formula (2) include Li 2 CuSiO 4 , Li 2 CuTiO 4 , and Li 2 CuGeO 4 . Among these, Li 2 CuSiO 4 is preferable from the viewpoint of performance (particularly capacity improvement) when used as a positive electrode active material for a lithium ion secondary battery.
上記組成式(2)で表される化合物の結晶構造は、単斜晶構造であることが好ましい。特に、上記組成式(2)で表される化合物は、単斜晶構造が主相であることが好ましい。上記組成式(2)で表される化合物において、主相である結晶構造の存在量は特に限定的ではなく、上記組成式(2)で表される化合物全体を基準として80mol%以上であることが好ましく、90mol%以上であることがより好ましい。このため、上記組成式(2)で表される化合物は、単相の結晶構造からなる材料とすることもできるし、本発明の効果を損なわない範囲で、他の結晶構造を有する材料とすることもできる。なお、上記組成式(2)で表される化合物の結晶構造は、X線回折測定により確認することができる。
The crystal structure of the compound represented by the composition formula (2) is preferably a monoclinic structure. In particular, the compound represented by the composition formula (2) preferably has a monoclinic crystal structure as the main phase. In the compound represented by the composition formula (2), the amount of the crystal structure that is the main phase is not particularly limited, and is 80 mol% or more based on the whole compound represented by the composition formula (2). Is preferable, and it is more preferable that it is 90 mol% or more. For this reason, the compound represented by the composition formula (2) can be a material having a single-phase crystal structure, or a material having another crystal structure as long as the effects of the present invention are not impaired. You can also. The crystal structure of the compound represented by the composition formula (2) can be confirmed by X-ray diffraction measurement.
上記組成式(2)で表される化合物は、CuKα線によるX線回折図において、種々の位置にピークを有する。
The compound represented by the composition formula (2) has peaks at various positions in the X-ray diffraction pattern by CuKα rays.
例えば、Li2CuSiO4は、回折角2θが18.3~19.3°、26.3~27.0°、27.1~28.0°、28.8~29.6°、29.9~30.5°、32.3~32.9°、35.5~36.7°、38.6~39.9°、40.8~42.0°、43.6~45.2°、45.7~46.8°、47.1~48.3°、48.5~49.8°、50.8~52.7°、53.7~55.2°、55.6~58.2°、62.3~63.4°、63.8~65.1°、及び68.6~71.0°等にピークを有することが好ましい。
For example, Li 2 CuSiO 4 has a diffraction angle 2θ of 18.3 to 19.3 °, 26.3 to 27.0 °, 27.1 to 28.0 °, 28.8 to 29.6 °, 29. 9-30.5 °, 32.3-32.9 °, 35.5-36.7 °, 38.6-39.9 °, 40.8-42.0 °, 43.6-45.2 °, 45.7 to 46.8 °, 47.1 to 48.3 °, 48.5 to 49.8 °, 50.8 to 52.7 °, 53.7 to 55.2 °, 55.6 It preferably has peaks at -58.2 °, 62.3-63.4 °, 63.8-65.1 °, 68.6-71.0 °, and the like.
また、例えば、Li2CuGeO4は、回折角2θが17.9~19.2°、24.9~27.0°、31.6~33.4°、35.0~39.2°、41.2~43.4°、49.2~51.5°、53.2~55.4°、56.9~58.7°、60.1~62.7°、63.7~65.2°、66.5~68.5°、69.9~71.7°、72.7~75.5°、及び76.9~78.4°等にピークを有することが好ましい。
Also, for example, Li 2 CuGeO 4 has a diffraction angle 2θ of 17.9 to 19.2 °, 24.9 to 27.0 °, 31.6 to 33.4 °, 35.0 to 39.2 °, 41.2 to 43.4 °, 49.2 to 51.5 °, 53.2 to 55.4 °, 56.9 to 58.7 °, 60.1 to 62.7 °, 63.7 to 65 It preferably has peaks at .2 °, 66.5 to 68.5 °, 69.9 to 71.7 °, 72.7 to 75.5 °, 76.9 to 78.4 °, and the like.
上記組成式(2)で表される化合物の平均粒子径は特に限定的ではなく、Li+拡散経路の短縮化の観点から0.1~100μmであることが好ましく、0.1~50μmであることがより好ましい。なお、上記組成式(2)で表される化合物の平均粒子径は、走査型電子顕微鏡(SEM)により確認することができる。
The average particle size of the compound represented by the composition formula (2) is not particularly limited, and is preferably 0.1 to 100 μm, and preferably 0.1 to 50 μm from the viewpoint of shortening the Li + diffusion path. It is more preferable. In addition, the average particle diameter of the compound represented by the composition formula (2) can be confirmed by a scanning electron microscope (SEM).
上記組成式(2)で表される化合物の製造方法は、リチウムと、銅と、上記X2と、酸素とを含む混合物を加熱する工程を含む。
Method for producing a compound represented by the formula (2) include lithium, copper, and the X 2, the step of heating a mixture comprising oxygen.
リチウム含有化合物、銅含有化合物、X2含有化合物、酸素含有化合物等の各化合物の種類については特に限定的ではなく、リチウム、銅、X2、及び酸素の各元素を1種類ずつ含む4種類又はそれ以上の化合物を混合して用いることもでき、また、リチウム、銅、X2、及び酸素のうち、2種類又はそれ以上の元素を同時に含む化合物を原料の一部として用い、4種類未満の化合物を混合して用いることもできる。
Lithium-containing compounds, copper-containing compounds, X 2 containing compound is not particularly limited about the kind of each compound such as oxygen-containing compounds, lithium, copper, four or comprises one by one each element of X 2, and oxygen It is also possible to use a mixture of more compounds, and a compound containing two or more elements of lithium, copper, X 2 and oxygen at the same time is used as a part of the raw material, and less than four kinds A mixture of compounds can also be used.
これらの原料化合物としては、リチウム、銅、X2、及び酸素以外の金属元素(特に、希少金属元素)を含まない化合物が好ましい。また、原料化合物中に含まれるリチウム、銅、X2、及び酸素の各元素以外の元素については、後述する加熱処理により離脱又は揮発していくものであることが好ましい。
As these raw material compounds, compounds containing no metal elements other than lithium, copper, X 2 , and oxygen (particularly rare metal elements) are preferable. Moreover, it is preferable that elements other than each element of lithium, copper, X 2 , and oxygen contained in the raw material compound are separated or volatilized by a heat treatment described later.
このような原料化合物の具体例としては以下の化合物が挙げられる。
Specific examples of such raw material compounds include the following compounds.
リチウム含有化合物としては、シュウ酸リチウム(Li2C2O4);水酸化リチウム(LiOH);硝酸リチウム(LiNO3);塩化リチウム(LiCl);炭酸リチウム(Li2CO3)などが挙げられる。
Examples of the lithium-containing compound include lithium oxalate (Li 2 C 2 O 4 ); lithium hydroxide (LiOH); lithium nitrate (LiNO 3 ); lithium chloride (LiCl); lithium carbonate (Li 2 CO 3 ) and the like. .
銅含有化合物としては、金属銅(Cu);酸化銅(CuO);水酸化銅(Cu(OH)2);炭酸銅(CuCO3);シュウ酸銅(CuC2O4);塩化第二銅(CuCl2);硫酸第二銅(CuSO4);硝酸第二銅(Cu(NO3)2);硫酸第二銅(CuSO4)等が挙げられる。
Examples of the copper-containing compound include metal copper (Cu); copper oxide (CuO); copper hydroxide (Cu (OH) 2 ); copper carbonate (CuCO 3 ); copper oxalate (CuC 2 O 4 ); cupric chloride (CuCl 2 ); cupric sulfate (CuSO 4 ); cupric nitrate (Cu (NO 3 ) 2 ); cupric sulfate (CuSO 4 ) and the like.
チタン含有化合物としては、四塩化チタン(TiCl4);水酸化チタン(Ti(OH)2)等が挙げられる。ケイ素含有化合物としては、ケイ素(Si);酸化ケイ素(SiO2)等が挙げられる。
Examples of the titanium-containing compound include titanium tetrachloride (TiCl 4 ) and titanium hydroxide (Ti (OH) 2 ). Examples of the silicon-containing compound include silicon (Si); silicon oxide (SiO 2 ) and the like.
ゲルマニウム化合物としては、ゲルマニウム(Ge);酸化ゲルマニウム(GeO2)等が挙げられる。
Examples of the germanium compound include germanium (Ge); germanium oxide (GeO 2 ) and the like.
酸素含有化合物としては、水酸化リチウム(LiOH);炭酸リチウム(Li2CO3);酸化銅(CuO);水酸化銅(Cu(OH)2);炭酸銅(CuCO3);シュウ酸銅(CuC2O4);酸化ケイ素(SiO2);酸化チタン(TiO2);水酸化チタン(Ti(OH)2);酸化ゲルマニウム(GeO2)等が挙げられる。
Examples of the oxygen-containing compound include lithium hydroxide (LiOH); lithium carbonate (Li 2 CO 3 ); copper oxide (CuO); copper hydroxide (Cu (OH) 2 ); copper carbonate (CuCO 3 ); copper oxalate ( CuC 2 O 4 ); silicon oxide (SiO 2 ); titanium oxide (TiO 2 ); titanium hydroxide (Ti (OH) 2 ); germanium oxide (GeO 2 ) and the like.
なお、これらの原料化合物は水和物を使用することもできる。
In addition, a hydrate can also be used for these raw material compounds.
また、上記組成式(2)で表される化合物の製造方法において使用する原料化合物は、市販品を用いることもできるし、適宜合成して使用することもできる。各原料化合物を合成する場合の合成方法は特に限定的ではなく、公知の方法に従って行うことができる。
In addition, as the raw material compound used in the method for producing the compound represented by the composition formula (2), a commercially available product can be used, or it can be synthesized and used as appropriate. The synthesis method in the case of synthesizing each raw material compound is not particularly limited, and can be carried out according to a known method.
これら原料化合物の形状については特に制限されない。取り扱い易さ等の観点からは、粉末状であることが好ましい。また、反応性の観点からは、粒子が微細である方が好ましく、平均粒子径が1μm以下(好ましくは、10~100nm程度、特に好ましくは60~80nm程度)の粉末状であることがより好ましい。なお、原料化合物の平均粒子径は、走査型電子顕微鏡(SEM)により測定することができる。
The shape of these raw material compounds is not particularly limited. From the viewpoint of ease of handling and the like, a powder form is preferable. Further, from the viewpoint of reactivity, it is preferable that the particles are fine, and it is more preferable that the particles have a mean particle size of 1 μm or less (preferably about 10 to 100 nm, particularly preferably about 60 to 80 nm). . In addition, the average particle diameter of a raw material compound can be measured with a scanning electron microscope (SEM).
リチウムと、銅と、X2と、酸素とを含む混合物は、上記した原料化合物のうち必要な材料を混合することにより得ることができる。
Lithium, and copper, and X 2, mixture comprising oxygen can be obtained by mixing the necessary materials of the feed compounds described above.
各原料化合物の混合割合については特に限定的ではなく、最終生成物である上記組成式(2)で表される化合物が有する組成となるように混合することが好ましい。原料化合物の混合割合は、原料化合物に含まれる各元素の比率が、生成される上記組成式(2)で表される化合物中の各元素の比率と同一となるようにすることが好ましい。
The mixing ratio of each raw material compound is not particularly limited, and it is preferable to mix so as to have a composition possessed by the compound represented by the composition formula (2) which is the final product. The mixing ratio of the raw material compounds is preferably such that the ratio of each element contained in the raw material compound is the same as the ratio of each element in the compound represented by the composition formula (2) to be generated.
リチウムと、銅と、X2と、酸素とを含む混合物を調製するための方法としては特に限定的ではなく、各原料化合物を均一に混合できる方法を採用することができる。例えば、乳鉢混合、メカニカルミリング処理、共沈法、各原料化合物を溶媒中に分散させた後に混合する方法、各原料化合物を溶媒中で一度に分散させて混合させる方法などを採用することができる。これらの中でも、乳鉢混合を採用することにより簡便な方法によって混合物を得ることができ、また、共沈法を採用することにより均一な混合物を得ることができる。
Lithium, and copper, and X 2, not particularly limited as methods for preparing the mixture comprising oxygen, it is possible to employ a method of each raw material compound can be uniformly mixed. For example, mortar mixing, mechanical milling treatment, coprecipitation method, a method of mixing after each raw material compound is dispersed in a solvent, a method of dispersing each raw material compound at once in a solvent and mixing, etc. can be adopted. . Among these, a mixture can be obtained by a simple method by employing mortar mixing, and a uniform mixture can be obtained by employing a coprecipitation method.
また、混合手段としてメカニカルミリング処理を行う場合、メカニカルミリング装置としては、例えば、ボールミル、振動ミル、ターボミル、ディスクミル等を用いることができ、中でもボールミルが好ましい。また、メカニカルミリング処理を行う場合には、混合と加熱を同時に行うことが好ましい。
Further, when performing mechanical milling as the mixing means, for example, a ball mill, a vibration mill, a turbo mill, a disk mill, or the like can be used as the mechanical milling device, and a ball mill is preferable. Moreover, when performing a mechanical milling process, it is preferable to perform mixing and a heating simultaneously.
混合時及び加熱時の雰囲気は特に限定的ではなく、例えば、アルゴン、窒素等の不活性ガス雰囲気、水素ガス雰囲気などを採用することができる。また、真空等の減圧下で混合及び加熱を行ってもよい。
The atmosphere during mixing and heating is not particularly limited. For example, an inert gas atmosphere such as argon or nitrogen, a hydrogen gas atmosphere, or the like can be employed. Further, mixing and heating may be performed under reduced pressure such as vacuum.
リチウムと、銅と、X2と、酸素とを含む混合物を加熱する際に、加熱温度としては特に限定的ではなく、得られる上記組成式(2)で表される化合物の結晶性及び電極特性(容量及び電位)をより向上させる観点から、600℃以上とすることが好ましく、700℃以上とすることがより好ましく、800℃以上とすることがさらに好ましく、900℃以上とすることが特に好ましい。なお、加熱温度の上限については特に限定的ではなく、上記組成式(2)で表される化合物の製造を容易に行うことができる程度の温度(例えば、1500℃程度)であればよい。換言すると、加熱温度としては、600~1500℃とすることが好ましく、700~1500℃とすることがより好ましく、800~1500℃とすることがさらに好ましく、900~1500℃とすることが特に好ましい。
Lithium, and copper, and X 2, when heating a mixture comprising oxygen, crystallinity and electrode characteristics of heating is not particularly limited as temperature, the compound represented by the obtained above composition formula (2) From the viewpoint of further improving (capacity and potential), it is preferably 600 ° C. or higher, more preferably 700 ° C. or higher, further preferably 800 ° C. or higher, and particularly preferably 900 ° C. or higher. . The upper limit of the heating temperature is not particularly limited as long as the temperature is such that the compound represented by the composition formula (2) can be easily produced (for example, about 1500 ° C.). In other words, the heating temperature is preferably 600 to 1500 ° C., more preferably 700 to 1500 ° C., further preferably 800 to 1500 ° C., and particularly preferably 900 to 1500 ° C. .
本発明のリチウムイオン二次電池用正極活物質は、上記した組成式(1)で表される化合物又は組成式(2)で表される化合物と炭素材料(例えば、アセチレンブラック等のカーボンブラックなどの材料)とが複合体を形成していてもよい。これにより、焼成時に炭素材料が粒子成長を抑制するため、電極特性に優れた微粒子のリチウムイオン二次電池用正極活物質を得ることが可能となる。この場合、炭素材料の含有量は、本発明のリチウムイオン二次電池用正極活物質中に好ましくは1~30質量%、より好ましくは3~20質量%、特に好ましくは5~15質量%である。
The positive electrode active material for a lithium ion secondary battery of the present invention includes a compound represented by the above composition formula (1) or a compound represented by the composition formula (2) and a carbon material (for example, carbon black such as acetylene black) And a material) may form a composite. Thus, since the carbon material suppresses particle growth during firing, it is possible to obtain a fine electrode positive electrode active material for a lithium ion secondary battery having excellent electrode characteristics. In this case, the content of the carbon material is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and particularly preferably 5 to 15% by mass in the positive electrode active material for a lithium ion secondary battery of the present invention. is there.
本発明のリチウムイオン二次電池用正極活物質は、上記した組成式(1)で表される化合物又は組成式(2)で表される化合物を含有している。本発明のリチウムイオン二次電池用正極活物質は、上記した組成式(1)で表される化合物又は組成式(2)で表される化合物のみで構成されていてもよいし、上記した組成式(1)で表される化合物又は組成式(2)で表される化合物の他に不可避不純物を含んでいてもよい。このような不可避不純物としては、上記した原料化合物などを挙げられる。不可避不純物の含有量としては、本発明の効果を損なわない範囲で、10mol%以下、好ましくは5mol%以下、より好ましくは2mol%以下である。
The positive electrode active material for a lithium ion secondary battery of the present invention contains the compound represented by the above composition formula (1) or the compound represented by the composition formula (2). The positive electrode active material for a lithium ion secondary battery of the present invention may be composed of only the compound represented by the composition formula (1) or the compound represented by the composition formula (2), or the composition described above. In addition to the compound represented by the formula (1) or the compound represented by the composition formula (2), an unavoidable impurity may be included. Examples of such inevitable impurities include the raw material compounds described above. The content of inevitable impurities is 10 mol% or less, preferably 5 mol% or less, more preferably 2 mol% or less, as long as the effects of the present invention are not impaired.
4.リチウムイオン二次電池用正極及びリチウムイオン二次電池
本発明のリチウムイオン二次電池用正極質及びリチウムイオン二次電池は、上記した組成式(1)で表される化合物又は組成式(2)で表される化合物を正極活物質として使用すること以外は、基本的な構造は、公知の非水電解液(非水系)リチウムイオン二次電池用正極及び非水電解液(非水系)リチウムイオン二次電池と同様の構成を採用することができる。例えば、正極、負極、及びセパレータを、当該正極及び負極がセパレータによって互いに隔離されるように電池容器内に配置することができる。その後、非水電解液を当該電池容器内に充填した後、当該電池容器を密封することなどによって本発明のリチウムイオン二次電池を製造することができる。なお、本発明のリチウムイオン二次電池は、リチウム二次電池であってもよい。本明細書において、「リチウムイオン二次電池」は、リチウムイオンをキャリアイオンとする二次電池を意味し、「リチウム二次電池」は、負極活物質としてリチウム金属又はリチウム合金を使用する二次電池を意味する。 4). Positive electrode for lithium ion secondary battery and lithium ion secondary battery The positive electrode material for lithium ion secondary battery and lithium ion secondary battery of the present invention are the compound represented by the above composition formula (1) or the composition formula (2). The basic structure is the known positive electrode for non-aqueous electrolyte (non-aqueous) lithium ion secondary battery and non-aqueous electrolyte (non-aqueous) lithium ion, except that the compound represented by A configuration similar to that of the secondary battery can be employed. For example, the positive electrode, the negative electrode, and the separator can be disposed in the battery container such that the positive electrode and the negative electrode are separated from each other by the separator. Thereafter, the lithium ion secondary battery of the present invention can be manufactured by, for example, sealing the battery container after filling the battery container with the nonaqueous electrolytic solution. The lithium ion secondary battery of the present invention may be a lithium secondary battery. In the present specification, “lithium ion secondary battery” means a secondary battery using lithium ions as carrier ions, and “lithium secondary battery” means a secondary that uses lithium metal or a lithium alloy as a negative electrode active material. Means battery.
本発明のリチウムイオン二次電池用正極質及びリチウムイオン二次電池は、上記した組成式(1)で表される化合物又は組成式(2)で表される化合物を正極活物質として使用すること以外は、基本的な構造は、公知の非水電解液(非水系)リチウムイオン二次電池用正極及び非水電解液(非水系)リチウムイオン二次電池と同様の構成を採用することができる。例えば、正極、負極、及びセパレータを、当該正極及び負極がセパレータによって互いに隔離されるように電池容器内に配置することができる。その後、非水電解液を当該電池容器内に充填した後、当該電池容器を密封することなどによって本発明のリチウムイオン二次電池を製造することができる。なお、本発明のリチウムイオン二次電池は、リチウム二次電池であってもよい。本明細書において、「リチウムイオン二次電池」は、リチウムイオンをキャリアイオンとする二次電池を意味し、「リチウム二次電池」は、負極活物質としてリチウム金属又はリチウム合金を使用する二次電池を意味する。 4). Positive electrode for lithium ion secondary battery and lithium ion secondary battery The positive electrode material for lithium ion secondary battery and lithium ion secondary battery of the present invention are the compound represented by the above composition formula (1) or the composition formula (2). The basic structure is the known positive electrode for non-aqueous electrolyte (non-aqueous) lithium ion secondary battery and non-aqueous electrolyte (non-aqueous) lithium ion, except that the compound represented by A configuration similar to that of the secondary battery can be employed. For example, the positive electrode, the negative electrode, and the separator can be disposed in the battery container such that the positive electrode and the negative electrode are separated from each other by the separator. Thereafter, the lithium ion secondary battery of the present invention can be manufactured by, for example, sealing the battery container after filling the battery container with the nonaqueous electrolytic solution. The lithium ion secondary battery of the present invention may be a lithium secondary battery. In the present specification, “lithium ion secondary battery” means a secondary battery using lithium ions as carrier ions, and “lithium secondary battery” means a secondary that uses lithium metal or a lithium alloy as a negative electrode active material. Means battery.
本発明のリチウムイオン二次電池用正極は、上記した組成式(1)で表される化合物又は組成式(2)で表される化合物を含む正極活物質を正極集電体に担持した構造を採用することができる。例えば、上記した組成式(1)で表される化合物又は組成式(2)で表される化合物、導電助剤、及び必要に応じて結着剤を含有する正極材料を、正極集電体に塗布することにより製造することができる。
The positive electrode for a lithium ion secondary battery of the present invention has a structure in which a positive electrode active material containing a compound represented by the above composition formula (1) or a compound represented by the composition formula (2) is supported on a positive electrode current collector. Can be adopted. For example, a positive electrode material containing the compound represented by the above-described composition formula (1) or the compound represented by the composition formula (2), a conductive auxiliary agent, and a binder as necessary is used as a positive electrode current collector. It can be manufactured by coating.
導電助剤としては、例えば、アセチレンブラック、ケッチェンブラック、カーボンナノチューブ、気相法炭素繊維、カーボンナノファイバー、黒鉛、コークス類等の炭素材料を用いることができる。導電助剤の形状は特に限定的ではなく、例えば、粉末状等を採用することができる。
As the conductive aid, for example, carbon materials such as acetylene black, ketjen black, carbon nanotube, vapor grown carbon fiber, carbon nanofiber, graphite, coke, etc. can be used. The shape of the conductive auxiliary agent is not particularly limited, and for example, a powder form can be adopted.
結着剤としては、例えば、ポリフッ化ビニリデン樹脂、ポリテトラフルオロエチレン等のフッ素樹脂を用いることができる。
As the binder, for example, fluorine resins such as polyvinylidene fluoride resin and polytetrafluoroethylene can be used.
正極材料中の各種成分の含有量としては特に限定的ではなく、広い範囲内から適宜決定することができる。例えば、上記した組成式(1)で表される化合物又は組成式(2)で表される化合物を50~95体積%(特に、70~90体積%)、導電助剤を2.5~25体積%(特に、5~15体積%)、及び結着剤を2.5~25体積%(特に、5~15体積%)含有することが好ましい。
The content of various components in the positive electrode material is not particularly limited, and can be appropriately determined from a wide range. For example, the compound represented by the composition formula (1) or the compound represented by the composition formula (2) is 50 to 95% by volume (particularly 70 to 90% by volume), and the conductive assistant is 2.5 to 25%. It is preferable to contain volume% (especially 5 to 15 volume%) and 2.5 to 25 volume% (particularly 5 to 15 volume%) of a binder.
正極集電体を構成する材料としては、例えば、アルミニウム、白金、モリブデン、ステンレス等が挙げられる。正極集電体の形状としては、例えば、多孔質体、箔、板、繊維からなるメッシュ等が挙げられる。
Examples of the material constituting the positive electrode current collector include aluminum, platinum, molybdenum, and stainless steel. Examples of the shape of the positive electrode current collector include a porous body, a foil, a plate, and a mesh made of fibers.
なお、正極集電体に対する正極材料の塗布量は特に限定的ではなく、リチウムイオン二次電池の用途等に応じて適宜決定することが好ましい。
It should be noted that the amount of the positive electrode material applied to the positive electrode current collector is not particularly limited, and is preferably determined appropriately according to the use of the lithium ion secondary battery.
負極を構成する負極活物質としては、例えば、リチウム金属;ケイ素;ケイ素含有Clathrate化合物;リチウム合金;M1M2
2O4(M1:Co、Ni、Mn、Sn等、M2:Mn、Fe、Zn等)で表される三元又は四元酸化物;M3
3O4(M3:Fe、Co、Ni、Mn等)、M4
2O3(M4:Fe、Co、Ni、Mn等)、MnV2O6、M5O2(M5:Sn、Ti等)、M6O(M6:Fe、Co、Ni、Mn、Sn、Cu等)等で表される金属酸化物;黒鉛、ハードカーボン、ソフトカーボン、グラフェン;上記した炭素材料;Li2C6H4O4、Li2C8H4O4、Li2C16H8O4等のような有機系化合物等が挙げられる。
Examples of the negative electrode active material constituting the negative electrode include lithium metal; silicon; silicon-containing acrylate compound; lithium alloy; M 1 M 2 2 O 4 (M 1 : Co, Ni, Mn, Sn, etc., M 2 : Mn, Ternary or quaternary oxides represented by Fe, Zn, etc .; M 3 3 O 4 (M 3 : Fe, Co, Ni, Mn, etc.), M 4 2 O 3 (M 4 : Fe, Co, Ni) , Mn, etc.), MnV 2 O 6 , M 5 O 2 (M 5 : Sn, Ti etc.), M 6 O (M 6 : Fe, Co, Ni, Mn, Sn, Cu etc.) Oxides; graphite, hard carbon, soft carbon, graphene; carbon materials described above; organic systems such as Li 2 C 6 H 4 O 4 , Li 2 C 8 H 4 O 4 , Li 2 C 16 H 8 O 4 Compounds and the like.
リチウム合金としては、例えば、リチウム及びアルミニウムを構成元素として含む合金、リチウム及び亜鉛を構成元素として含む合金、リチウム及び鉛を構成元素として含む合金、リチウム及びマンガンを構成元素として含む合金、リチウム及びビスマスを構成成分として含む合金、リチウム及びニッケルを構成元素として含む合金、リチウム及びアンチモンを構成元素として含む合金、リチウム及びスズを構成元素として含む合金、リチウム及びインジウムを構成元素として含む合金;金属(スカンジウム、チタン、バナジウム、クロム、ジルコニウム、ニオブ、モリブデン、ハフニウム、タンタル等)とカーボンを構成元素として含むMXene系合金、M7
xBC3系合金(M7:Sc、Ti、V、Cr、Zr、Nb、Mo、Hf、Ta等)等の四元系層状炭化又は窒化化合物等が挙げられる。
Examples of lithium alloys include alloys containing lithium and aluminum as constituent elements, alloys containing lithium and zinc as constituent elements, alloys containing lithium and lead as constituent elements, alloys containing lithium and manganese as constituent elements, lithium and bismuth. Alloys containing lithium and nickel as constituent elements, alloys containing lithium and antimony as constituent elements, alloys containing lithium and tin as constituent elements, alloys containing lithium and indium as constituent elements; metal (scandium) , Titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, and the like) and carbon containing MXene alloy, M 7 x BC 3 alloy (M 7 : Sc, Ti, V, Cr, Zr, Nb, Mo, Hf Ta, etc.) quaternary layered carbide or nitride compounds such like.
負極は、負極活物質から構成することもでき、また、負極活物質、導電助剤、及び必要に応じて結着剤を含有する負極材料が負極集電体上に担持する構成を採用することもできる。負極材料が負極集電体上に担持する構成を採用する場合、負極活物質、導電助剤、及び必要に応じて結着剤を含有する負極合剤を、負極集電体に塗布することで製造することができる。
The negative electrode can be composed of a negative electrode active material, and a configuration in which a negative electrode material containing a negative electrode active material, a conductive additive, and a binder as required is supported on the negative electrode current collector is adopted. You can also. When adopting a configuration in which the negative electrode material is supported on the negative electrode current collector, a negative electrode mixture containing a negative electrode active material, a conductive additive, and a binder as necessary is applied to the negative electrode current collector. Can be manufactured.
負極が負極活物質から構成する場合、上記の負極活物質を電極に適した形状(板状等)
に成形して得ることができる。 When the negative electrode is composed of a negative electrode active material, the above negative electrode active material has a shape suitable for an electrode (plate shape, etc.)
It can be obtained by molding.
に成形して得ることができる。 When the negative electrode is composed of a negative electrode active material, the above negative electrode active material has a shape suitable for an electrode (plate shape, etc.)
It can be obtained by molding.
また、負極材料が負極集電体上に担持する構成を採用する場合、導電助剤及び結着剤の種類、並びに負極活物質、導電助剤及び結着剤の含有量は上記した正極のものを適用することができる。負極集電体を構成する材料としては、例えば、アルミニウム、銅、ニッケル、ステンレス等が挙げられる。前記負極集電体の形状としては、例えば、多孔質体、箔、板、繊維からなるメッシュ等が挙げられる。なお、負極集電体に対する負極材料の塗布量は、リチウムイオン二次電池の用途等に応じて適宜決定することが好ましい。
In addition, when adopting a configuration in which the negative electrode material is supported on the negative electrode current collector, the types of the conductive auxiliary agent and the binder, and the negative electrode active material, the conductive auxiliary agent, and the binder content are those of the positive electrode described above. Can be applied. Examples of the material constituting the negative electrode current collector include aluminum, copper, nickel, and stainless steel. Examples of the shape of the negative electrode current collector include a porous body, a foil, a plate, and a mesh made of fibers. In addition, it is preferable to determine suitably the application quantity of the negative electrode material with respect to a negative electrode collector according to the use etc. of a lithium ion secondary battery.
セパレータとしては、電池中で正極と負極とを隔離し、かつ電解液を保持して正極と負極との間のイオン伝導性を確保することができる材料からなるものであれば制限はない。例えば、ポリエチレン、ポリプロピレン、ポリイミド、ポリビニルアルコール、末端アミノ化ポリエチレンオキシド等のポリオレフィン樹脂;ポリテトラフルオロエチレン等のフッ素樹脂;アクリル樹脂;ナイロン;芳香族アラミド;無機ガラス;セラミックス等の材質からなり、多孔質膜、不織布、織布等の形態の材料を用いることができる。
The separator is not limited as long as it is made of a material that can separate the positive electrode and the negative electrode in the battery and can hold the electrolyte solution to ensure the ionic conductivity between the positive electrode and the negative electrode. For example, polyolefin resin such as polyethylene, polypropylene, polyimide, polyvinyl alcohol, terminal aminated polyethylene oxide; fluorine resin such as polytetrafluoroethylene; acrylic resin; nylon; aromatic aramid; inorganic glass; Materials in the form of a membrane, nonwoven fabric, woven fabric, etc. can be used.
非水電解液は、リチウムイオンを含む電解液が好ましい。このような電解液としては、例えば、リチウム塩の溶液、リチウムを含む無機材料で構成されるイオン液体等が挙げられる。
The non-aqueous electrolyte is preferably an electrolyte containing lithium ions. Examples of such an electrolytic solution include a lithium salt solution, an ionic liquid composed of an inorganic material containing lithium, and the like.
リチウム塩としては、例えば、塩化リチウム、臭化リチウム、ヨウ化リチウム等のハロゲン化リチウム;過塩素酸リチウム、テトラフルオロホウ酸リチウム、ヘキサフルオロリン酸リチウム、ヘキサフルオロヒ酸リチウム等のリチウム無機塩化合物;ビス(トリフルオロメチルスルホニル)イミドリチウム、ビス(パフルオロエタンスルホニル)イミドリチウム、安息香酸リチウム、サリチル酸リチウム、フタル酸リチウム、酢酸リチウム、プロピオン酸リチウム、グリニャール試薬等のリチウム有機塩化合物等が挙げられる。
Examples of the lithium salt include lithium halides such as lithium chloride, lithium bromide and lithium iodide; lithium inorganic salts such as lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate and lithium hexafluoroarsenate Compound: Lithium organic salt compounds such as bis (trifluoromethylsulfonyl) imide lithium, bis (perfluoroethanesulfonyl) imide lithium, lithium benzoate, lithium salicylate, lithium phthalate, lithium acetate, lithium propionate, Grignard reagent, etc. Can be mentioned.
また、溶媒としては、例えば、プロピレンカーボネート、エチレンカーボネート、ジメトルカーボネート、エチルメチルカーボネート、ジエチルカーボネート等のカーボネート化合物;γ-ブチロラクトン、γ-バレロラクトンなどのラクトン化合物;テトラヒドロフラン、2-メチルテトラヒドロフラン、ジエチルエーテル、ジイソプロピルエーテル、ジブチルエーテル、メトキシメタン、グライム、ジメトキシエタン、ジメトキシメタン、ジエトキシメタン、ジエトキシエタン、プロピレングリコールジメチルエーテルなどのエーテル化合物;アセトニトリル;N,N-ジメチルホルムアミド;N-プロピル-N-メチルピロリジニウムビス(トリフルオロメタンスルホニル)イミド等が挙げられる。
Examples of the solvent include carbonate compounds such as propylene carbonate, ethylene carbonate, dimethol carbonate, ethylmethyl carbonate, and diethyl carbonate; lactone compounds such as γ-butyrolactone and γ-valerolactone; tetrahydrofuran, 2-methyltetrahydrofuran, diethyl Ether compounds such as ether, diisopropyl ether, dibutyl ether, methoxymethane, glyme, dimethoxyethane, dimethoxymethane, diethoxymethane, diethoxyethane, propylene glycol dimethyl ether; acetonitrile; N, N-dimethylformamide; N-propyl-N- And methylpyrrolidinium bis (trifluoromethanesulfonyl) imide.
また、上記非水電解液の代わりに固体電解質を使用することもできる。固体電解質としては、例えば、Li10GeP2S12、Li7P3S11、Li7La3Zr2O12、La0.51Li0.34TiO2.94等のリチウムイオン伝導体等が列挙される。
Further, a solid electrolyte can be used instead of the non-aqueous electrolyte. Examples of the solid electrolyte include lithium ion conductors such as Li 10 GeP 2 S 12 , Li 7 P 3 S 11 , Li 7 La 3 Zr 2 O 12 , La 0.51 Li 0.34 TiO 2.94, and the like. Enumerated.
このような本発明のリチウムイオン二次電池は、組成式(1)で表される化合物又は組成式(2)で表される化合物が用いられているので、酸化還元反応(充放電反応)に際し、より高い電位及びエネルギー密度を確保することができ、しかも、安全性(ポリアニオン骨格)及び実用性に優れる。したがって、本発明のリチウムイオン二次電池は、例えば、小型化及び高性能化が求められるデバイス等に好適に用いることができる。
In such a lithium ion secondary battery of the present invention, since the compound represented by the composition formula (1) or the compound represented by the composition formula (2) is used, the oxidation-reduction reaction (charge / discharge reaction) is performed. A higher potential and energy density can be ensured, and safety (polyanion skeleton) and practicality are excellent. Therefore, the lithium ion secondary battery of the present invention can be suitably used, for example, for devices that are required to be downsized and high performance.
以下、実施例を挙げて本発明をさらに詳細に説明するが、本発明は下記の例に限定されるものではない。
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.
実施例1:Li 2 CuSiO 4 の合成
原料粉体として、Li2CO3(レアメタリック社製;99.9%(3N))、CuO(高純度化学研究所社製;99.99%(4N))、及び沈降性非晶質SiO2(関東化学社製;3N)を用いた。Li2CO3、CuO、及びSiO2をリチウム:銅:ケイ素(モル比)が2:1:1となるように秤量し、ジルコニアボール(15mmΦ×10個)と共にクロム鋼製容器に入れ、アセトンを加えて遊星ボールミル(Fritsch社製、商品名:P-6)にて、400rpmで24時間粉砕混合した。その後、減圧下でアセトンを除去した後、回収した粉末を手押しでペレット成型し、アルゴン気流下にて600℃、700℃、800℃、900℃、又は1000℃で1時間焼成した。このとき、昇温速度を400℃/hとした。また、冷却速度は300℃まで100℃/hとし、以降は自然冷却により室温まで放冷した。得られた各生成物(Li2CuSiO4)を粉末X線回折(XRD)により確認した。結果を図1に示す。 Example 1: A synthetic material powder of Li 2 CuSiO 4, Li 2 CO 3 ( manufactured by Rare Metallic Co.; 99.9% (3N)), CuO ( Kojundo Chemical Laboratory Co., Ltd.; 99.99% (4N )), And precipitated amorphous SiO 2 (manufactured by Kanto Chemical Co .; 3N). Li 2 CO 3 , CuO, and SiO 2 were weighed so that the ratio of lithium: copper: silicon (molar ratio) was 2: 1: 1, and placed in a chrome steel container together with zirconia balls (15 mmΦ × 10 pieces). The mixture was pulverized and mixed for 24 hours at 400 rpm in a planetary ball mill (manufactured by Fritsch, trade name: P-6). Then, after removing acetone under reduced pressure, the recovered powder was pelleted by hand pressing and calcined at 600 ° C., 700 ° C., 800 ° C., 900 ° C., or 1000 ° C. for 1 hour under an argon stream. At this time, the temperature rising rate was 400 ° C./h. The cooling rate was set to 100 ° C./h up to 300 ° C., and thereafter, the mixture was naturally cooled to room temperature. Each obtained product (Li 2 CuSiO 4 ) was confirmed by powder X-ray diffraction (XRD). The results are shown in FIG.
原料粉体として、Li2CO3(レアメタリック社製;99.9%(3N))、CuO(高純度化学研究所社製;99.99%(4N))、及び沈降性非晶質SiO2(関東化学社製;3N)を用いた。Li2CO3、CuO、及びSiO2をリチウム:銅:ケイ素(モル比)が2:1:1となるように秤量し、ジルコニアボール(15mmΦ×10個)と共にクロム鋼製容器に入れ、アセトンを加えて遊星ボールミル(Fritsch社製、商品名:P-6)にて、400rpmで24時間粉砕混合した。その後、減圧下でアセトンを除去した後、回収した粉末を手押しでペレット成型し、アルゴン気流下にて600℃、700℃、800℃、900℃、又は1000℃で1時間焼成した。このとき、昇温速度を400℃/hとした。また、冷却速度は300℃まで100℃/hとし、以降は自然冷却により室温まで放冷した。得られた各生成物(Li2CuSiO4)を粉末X線回折(XRD)により確認した。結果を図1に示す。 Example 1: A synthetic material powder of Li 2 CuSiO 4, Li 2 CO 3 ( manufactured by Rare Metallic Co.; 99.9% (3N)), CuO ( Kojundo Chemical Laboratory Co., Ltd.; 99.99% (4N )), And precipitated amorphous SiO 2 (manufactured by Kanto Chemical Co .; 3N). Li 2 CO 3 , CuO, and SiO 2 were weighed so that the ratio of lithium: copper: silicon (molar ratio) was 2: 1: 1, and placed in a chrome steel container together with zirconia balls (15 mmΦ × 10 pieces). The mixture was pulverized and mixed for 24 hours at 400 rpm in a planetary ball mill (manufactured by Fritsch, trade name: P-6). Then, after removing acetone under reduced pressure, the recovered powder was pelleted by hand pressing and calcined at 600 ° C., 700 ° C., 800 ° C., 900 ° C., or 1000 ° C. for 1 hour under an argon stream. At this time, the temperature rising rate was 400 ° C./h. The cooling rate was set to 100 ° C./h up to 300 ° C., and thereafter, the mixture was naturally cooled to room temperature. Each obtained product (Li 2 CuSiO 4 ) was confirmed by powder X-ray diffraction (XRD). The results are shown in FIG.
さらに、焼成温度を900℃とした場合に得られたLi2CuSiO4と、原料化合物であるCuO、並びに原料化合物であるLi2CO3及びSiO2から生成されるLi2SiO3とのX線回折パターンを比較した結果を図2に示す。
Further, X-rays of Li 2 CuSiO 4 obtained when the firing temperature is set to 900 ° C., CuO as the raw material compound, and Li 2 SiO 3 generated from the raw material compounds Li 2 CO 3 and SiO 2 The result of comparing the diffraction patterns is shown in FIG.
なお、粉末X線回折(XRD)測定には、X線回折測定装置(リガク社製、商品名:RINT2200)を使用し、X線源はモノクロメーターで単色化されたCuKαを使用した。測定条件は、管電圧を5kV、管電流を300mAとしてデータ収集を行った。このとき、強度を約10000カウントとなるよう、走査速度を設定した。また、測定に使用する試料は粒子が均一となるように十分に粉砕した。構造解析には、リートベルト解析を行い、解析プログラムにはJANA-2006を使用した。
In addition, for powder X-ray diffraction (XRD) measurement, an X-ray diffraction measurement device (manufactured by Rigaku Corporation, trade name: RINT2200) was used, and the X-ray source was CuKα monochromatized with a monochromator. Data were collected under the measurement conditions of a tube voltage of 5 kV and a tube current of 300 mA. At this time, the scanning speed was set so that the intensity was about 10,000 counts. The sample used for measurement was sufficiently pulverized so that the particles were uniform. Rietveld analysis was performed for the structural analysis, and JANA-2006 was used as the analysis program.
図1から、焼成温度が800℃以上である場合には、少なくとも2θ値15~70°に複数の主要ピークが見られることが確認された。また、2θ値15~70°に見られるピークは、焼成温度が高いほど強いピークとなっていることから、焼成温度は高い方が好ましいことが分かった。
FIG. 1 confirms that when the firing temperature is 800 ° C. or higher, a plurality of main peaks are observed at least at 2θ values of 15 to 70 °. Further, since the peak observed at 2θ value of 15 to 70 ° is stronger as the firing temperature is higher, it was found that a higher firing temperature is preferable.
図1から、2θ値15~70°に確認された複数の主要ピークは、単相のLi2CuSiO4に対応することから、生成物として単相のLi2CuSiO4が得られていることが分かった。さらに、図2から、原料化合物であるCuO、並びに原料化合物であるLi2CO3及びSiO2から生成されるLi2SiO3に由来するピークが確認されなかったことからも、単相のLi2CuSiO4が得られていることが分かった。
From FIG. 1, the plurality of main peaks confirmed at 2θ values of 15 to 70 ° correspond to single-phase Li 2 CuSiO 4 , and thus single-phase Li 2 CuSiO 4 is obtained as a product. I understood. Further, from FIG. 2, CuO which is a raw material compound, and from the fact that peaks derived from Li 2 SiO 3 generated from Li 2 CO 3 and SiO 2 which is a raw material compound is not verified, the single-phase Li 2 It was found that CuSiO 4 was obtained.
また、図1から、焼成温度を900℃とした場合に得られたLi2CuSiO4の結晶は、粉末X線回折によるX線回折パターンにおいて、2θで表される回折角度が18.31~19.24°、26.39~26.96°、27.22~27.39°、28.90~29.59°、38.65~39.82°、40.88~41.92°、43.63~45.12°、45.72~46.70°、47.21~48.23°、48.56~49.71°、50.87~52.69°、53.81~55.14°、55.66~58.17°、62.40~63.33°、63.88~65.04°、及び68.67~70.90°にピークを有することが分かった。当該結果から、得られたLi2CuSiO4の結晶は、単斜晶構造(空間群C2/m)を有し、格子定数がa=6.457~6.484Å、b=3.340~3.345Å、c=9.504~11.183Å、β=93.65~121.78°であり、単位格子体積(V)が205.1~206.0Å3である結晶であることが分かった。
Also, from FIG. 1, the Li 2 CuSiO 4 crystals obtained when the firing temperature was set to 900 ° C. had a diffraction angle expressed by 2θ of 18.31 to 19 in an X-ray diffraction pattern by powder X-ray diffraction. .24 °, 26.39 to 26.96 °, 27.22 to 27.39 °, 28.90 to 29.59 °, 38.65 to 39.82 °, 40.88 to 41.92 °, 43 63 to 45.12 °, 45.72 to 46.70 °, 47.21 to 48.23 °, 48.56 to 49.71 °, 50.87 to 52.69 °, 53.81 to 55. It was found to have peaks at 14 °, 55.66-58.17 °, 62.40-63.33 °, 63.88-65.04 °, and 68.67-70.90 °. From the results, the obtained crystal of Li 2 CuSiO 4 has a monoclinic structure (space group C2 / m), the lattice constant is a = 6.457-6.48448, b = 3.340-3 .345Å, c = 9.504 ~ 11.183Å, a β = 93.65 ~ 121.78 °, the unit cell volume (V) was found to be crystalline is 205.1 ~ 206.0Å 3 .
さらに、焼成温度を900℃とした場合に得られたLi2CuSiO4を走査型電子顕微鏡(SEM)で観察した。結果を図3に示す。なお、図3中、スケールバーは11.7μmを示す。図3から、粒子径約3~10μmのLi2CuSiO4が得られていることが分かった。
Furthermore, Li 2 CuSiO 4 obtained when the firing temperature was 900 ° C. was observed with a scanning electron microscope (SEM). The results are shown in FIG. In FIG. 3, the scale bar indicates 11.7 μm. From FIG. 3, it was found that Li 2 CuSiO 4 having a particle diameter of about 3 to 10 μm was obtained.
また、ICP-AES法(測定装置:iCAP6500、サーモフィッシャーサイエンティフィック社製)により、焼成温度900℃の場合に得られた生成物の化学組成を測定したところ、Li2.08Cu1.05Si1.00O4であることが分かった。
Further, when the chemical composition of the product obtained when the firing temperature was 900 ° C. was measured by ICP-AES method (measuring device: iCAP6500, manufactured by Thermo Fisher Scientific), Li 2.08 Cu 1.05 was obtained. It was found to be Si 1.00 O 4 .
実施例2:Li 2 CuGeO 4 の合成
原料粉体として、Li2CO3(レアメタリック社製;99.9%(3N))、CuO(高純度化学研究所社製;99.99%(4N))、及びGeO2(関東化学社製;99.99%(4N))を用いた。Li2CO3、CuO、及びGeO2をリチウム:銅:ゲルマニウム(モル比)が2:1:1となるように秤量し、ジルコニアボール(15mmΦ×10個)と共にクロム鋼製容器に入れ、アセトンを加えて遊星ボールミル(Fritsch社製、商品名:P-6)にて、400rpmで24時間粉砕混合した。その後、減圧下でアセトンを除去した後、回収した粉末を手押しでペレット成型し、アルゴン気流下にて700℃、800℃、又は900℃で1時間焼成した。このとき、昇温速度を400℃/hとした。また、冷却速度は300℃まで100℃/hとし、以降は自然冷却により室温まで放冷した。得られた各生成物(Li2CuGeO4)を実施例1と同様にして粉末X線回折(XRD)により確認した。結果を図4に示す。 Example 2 Li 2 CO 3 (manufactured by Rare Metallic; 99.9% (3N)), CuO (manufactured by High-Purity Chemical Laboratories ); 99.99% (4N) as a synthetic raw material powder of Li 2 CuGeO 4 )), And GeO 2 (manufactured by Kanto Chemical Co .; 99.99% (4N)). Li 2 CO 3 , CuO, and GeO 2 were weighed so that the ratio of lithium: copper: germanium (molar ratio) was 2: 1: 1, placed in a chromium steel container together with zirconia balls (15 mmΦ × 10), and acetone The mixture was pulverized and mixed for 24 hours at 400 rpm in a planetary ball mill (manufactured by Fritsch, trade name: P-6). Then, after removing acetone under reduced pressure, the collected powder was pelleted by hand and baked at 700 ° C., 800 ° C., or 900 ° C. for 1 hour under an argon stream. At this time, the temperature rising rate was 400 ° C./h. The cooling rate was set to 100 ° C./h up to 300 ° C., and thereafter, the mixture was naturally cooled to room temperature. Each obtained product (Li 2 CuGeO 4 ) was confirmed by powder X-ray diffraction (XRD) in the same manner as in Example 1. The results are shown in FIG.
原料粉体として、Li2CO3(レアメタリック社製;99.9%(3N))、CuO(高純度化学研究所社製;99.99%(4N))、及びGeO2(関東化学社製;99.99%(4N))を用いた。Li2CO3、CuO、及びGeO2をリチウム:銅:ゲルマニウム(モル比)が2:1:1となるように秤量し、ジルコニアボール(15mmΦ×10個)と共にクロム鋼製容器に入れ、アセトンを加えて遊星ボールミル(Fritsch社製、商品名:P-6)にて、400rpmで24時間粉砕混合した。その後、減圧下でアセトンを除去した後、回収した粉末を手押しでペレット成型し、アルゴン気流下にて700℃、800℃、又は900℃で1時間焼成した。このとき、昇温速度を400℃/hとした。また、冷却速度は300℃まで100℃/hとし、以降は自然冷却により室温まで放冷した。得られた各生成物(Li2CuGeO4)を実施例1と同様にして粉末X線回折(XRD)により確認した。結果を図4に示す。 Example 2 Li 2 CO 3 (manufactured by Rare Metallic; 99.9% (3N)), CuO (manufactured by High-Purity Chemical Laboratories ); 99.99% (4N) as a synthetic raw material powder of Li 2 CuGeO 4 )), And GeO 2 (manufactured by Kanto Chemical Co .; 99.99% (4N)). Li 2 CO 3 , CuO, and GeO 2 were weighed so that the ratio of lithium: copper: germanium (molar ratio) was 2: 1: 1, placed in a chromium steel container together with zirconia balls (15 mmΦ × 10), and acetone The mixture was pulverized and mixed for 24 hours at 400 rpm in a planetary ball mill (manufactured by Fritsch, trade name: P-6). Then, after removing acetone under reduced pressure, the collected powder was pelleted by hand and baked at 700 ° C., 800 ° C., or 900 ° C. for 1 hour under an argon stream. At this time, the temperature rising rate was 400 ° C./h. The cooling rate was set to 100 ° C./h up to 300 ° C., and thereafter, the mixture was naturally cooled to room temperature. Each obtained product (Li 2 CuGeO 4 ) was confirmed by powder X-ray diffraction (XRD) in the same manner as in Example 1. The results are shown in FIG.
図4から、焼成温度が700℃以上である場合には、少なくとも2θ値15~80°に複数の主要ピークが見られることが確認された。これらのピークは、単相のLi2CuGeO4に対応することから、生成物として単相のLi2CuGeO4が得られていることが分かった。また、2θ値15~80°に見られるピークは、焼成温度が高いほど強いピークとなっていることから、焼成温度は高い方が好ましいことが分かった。
From FIG. 4, it was confirmed that when the firing temperature was 700 ° C. or higher, a plurality of main peaks were observed at least at 2θ values of 15 to 80 °. These peaks, since it corresponds to the Li 2 CuGeO 4 single-phase, Li 2 CuGeO 4 single-phase is found to be obtained as a product. Further, since the peak observed at the 2θ value of 15 to 80 ° is stronger as the firing temperature is higher, it was found that a higher firing temperature is preferable.
また、図4から、焼成温度を700℃とした場合に得られたLi2CuSiO4の結晶は、粉末X線回折によるX線回折パターンにおいて、2θで表される回折角度が17.94~19.15°、24.96~26.91°、31.65~33.32°、35.07~39.17°、41.30~43.39°、49.29~51.44°、53.24~55.30°、56.92~58.63°、60.16~62.63°、63.79~65.19°、66.57~68.44°、69.92~71.64°、72.80~75.41°、及び76.94~78.33°にピークを有することが分かった。当該結果から、得られたLi2CuGeO4の結晶は、単斜晶構造(空間群C2/m)を有し、格子定数がa=5.491~5.552Å、b=9.645~9.691Å、c=5.491~5.552Å、β=119.69~120.75°であり、単位格子体積(V)が256.1~256.6Å3である結晶であることが分かった。
Also, from FIG. 4, the Li 2 CuSiO 4 crystals obtained when the firing temperature was set to 700 ° C. had a diffraction angle of 17.94 to 19 expressed by 2θ in the X-ray diffraction pattern by powder X-ray diffraction. .15 °, 24.96 to 26.91 °, 31.65 to 33.32 °, 35.07 to 39.17 °, 41.30 to 43.39 °, 49.29 to 51.44 °, 53 24 to 55.30 °, 56.92 to 58.63 °, 60.16 to 62.63 °, 63.79 to 65.19 °, 66.57 to 68.44 °, 69.92 to 71. It was found to have peaks at 64 °, 72.80-75.41 °, and 76.94-78.33 °. From the results, the obtained crystal of Li 2 CuGeO 4 has a monoclinic structure (space group C2 / m), the lattice constants are a = 5.491 to 5.55255, and b = 9.645 to 9 .691Å, c = 5.491 ~ 5.552Å, a β = 119.69 ~ 120.75 °, the unit cell volume (V) was found to be crystalline is 256.1 ~ 256.6Å 3 .
さらに、焼成温度を900℃とした場合に得られたLi2CuGeO4を走査型電子顕微鏡(SEM)で観察した。結果を図5に示す。なお、図5中、スケールバーは27.0μmを示す。図5から、粒子径約1~50μmのLi2CuGeO4が得られていることが分かった。
Furthermore, Li 2 CuGeO 4 obtained when the firing temperature was 900 ° C. was observed with a scanning electron microscope (SEM). The results are shown in FIG. In FIG. 5, the scale bar indicates 27.0 μm. From FIG. 5, it was found that Li 2 CuGeO 4 having a particle diameter of about 1 to 50 μm was obtained.
また、EDX法(測定装置:JSM-7800F、日本電子株式会社製)により、焼成温度900℃の場合に得られた生成物の化学組成を測定したところ、CuとGeとの質量比は1:0.956であることが分かった。
Further, when the chemical composition of the product obtained when the firing temperature was 900 ° C. was measured by the EDX method (measuring device: JSM-7800F, manufactured by JEOL Ltd.), the mass ratio of Cu and Ge was 1: It was found to be 0.956.
実施例3:Li 2 CuSiO 4 の充放電特性の測定
充放電測定を行うために、上記実施例1において焼成温度900℃の場合に得られたLi2CuSiO4、ポリフッ化ビニリデン(PVDF)、及びアセチレンブラック(AB)が体積比85:7.5:7.5となるようにめのう乳鉢で混合し、得られたスラリーを正極集電体であるアルミニウム箔(厚さ20μm)上に塗布し、これを直径8mmの円形に打ち抜き、正極とした。また、試料が正極集電体から剥がれないようにするため、30~40mPaで圧着した。 Example 3: Li 2 to make measurements discharge measurements of the charge and discharge characteristics of CuSiO 4, Li 2 CuSiO 4 were obtained when the firing temperature 900 ° C. In the first embodiment, polyvinylidene fluoride (PVDF), and Acetylene black (AB) was mixed in an agate mortar so that the volume ratio was 85: 7.5: 7.5, and the resulting slurry was applied onto an aluminum foil (thickness 20 μm) as a positive electrode current collector, This was punched into a circle with a diameter of 8 mm to obtain a positive electrode. Further, in order to prevent the sample from being peeled off from the positive electrode current collector, it was pressure-bonded at 30 to 40 mPa.
充放電測定を行うために、上記実施例1において焼成温度900℃の場合に得られたLi2CuSiO4、ポリフッ化ビニリデン(PVDF)、及びアセチレンブラック(AB)が体積比85:7.5:7.5となるようにめのう乳鉢で混合し、得られたスラリーを正極集電体であるアルミニウム箔(厚さ20μm)上に塗布し、これを直径8mmの円形に打ち抜き、正極とした。また、試料が正極集電体から剥がれないようにするため、30~40mPaで圧着した。 Example 3: Li 2 to make measurements discharge measurements of the charge and discharge characteristics of CuSiO 4, Li 2 CuSiO 4 were obtained when the firing temperature 900 ° C. In the first embodiment, polyvinylidene fluoride (PVDF), and Acetylene black (AB) was mixed in an agate mortar so that the volume ratio was 85: 7.5: 7.5, and the resulting slurry was applied onto an aluminum foil (
負極には14mmφで打ち抜いた金属リチウムを使用し、セパレータは18mmφで切り抜いた多孔質膜(商品名:celgard 2500)を2枚使用した。電解液は、エチレンカーボネート(EC)及びジエチルカーボネート(DEC)を体積比1:2で混合した溶媒に支持電解質としてLiPF6を1mol/dm3の濃度で溶解した電解液(岸田化学社製)を使用した。電池の作製は、金属リチウムを使用すること、及び電解液に水分が混入した場合に抵抗増分増加の要因となること等の理由により、アルゴン雰囲気下のグローブブックス内で行った。セルは、図6に示すCR2032型コインセルを用いた。充放電試験に先立って、電極に電流を印加していない状態の電位(即ち、開回路電位)の測定を行った。定電流充放電測定は、電圧切り替え器を用い、C/20レート又はC/50レート、電流10mA/g、上限電圧4.8V、下限電圧1.5Vに設定し、充電より開始した。また、充放電測定は、55℃恒温槽内にセルを入れた状態で行った。開回路電位の測定結果を図7に、C/20レートでの充放電特性の測定結果(各サイクルと放電容量との関係)を図8、C/50レートでの充放電特性の測定結果を図9に示す。なお、Cレートとは電極活物質から理論容量分の充放電を1時間で行うのに必要な電流密度を意味する。
Metal lithium punched out at 14 mmφ was used for the negative electrode, and two porous membranes (trade name: celgard 2500) cut out at 18 mmφ were used as the separator. The electrolytic solution is an electrolytic solution (manufactured by Kishida Chemical Co., Ltd.) in which LiPF 6 is dissolved at a concentration of 1 mol / dm 3 as a supporting electrolyte in a solvent in which ethylene carbonate (EC) and diethyl carbonate (DEC) are mixed at a volume ratio of 1: 2. used. The battery was produced in Globe Books under an argon atmosphere because of the use of metallic lithium and the cause of increased resistance when water was mixed in the electrolyte. As the cell, a CR2032-type coin cell shown in FIG. 6 was used. Prior to the charge / discharge test, the potential in a state where no current was applied to the electrode (ie, open circuit potential) was measured. The constant current charge / discharge measurement was started from charging by using a voltage switch, setting a C / 20 rate or C / 50 rate, a current of 10 mA / g, an upper limit voltage of 4.8 V, and a lower limit voltage of 1.5 V. Moreover, the charge / discharge measurement was performed in a state where the cell was placed in a 55 ° C. constant temperature bath. FIG. 7 shows the measurement results of the open circuit potential, FIG. 8 shows the measurement results of the charge / discharge characteristics at the C / 20 rate (relationship between each cycle and the discharge capacity), and the measurement results of the charge / discharge characteristics at the C / 50 rate. As shown in FIG. The C rate means a current density necessary for charging / discharging the theoretical capacity from the electrode active material in one hour.
図7から、Li2CuSiO4の開回路電位は約3.0Vであることが分かった。また、図8から、C/20レートにおいて引き出し初期充電容量は約110mAh/gであることが分かった。なお、理論容量は316mAh/gであり、Li2CuSiO4の初回充放電容量は理論容量の約3分の1に相当する。また、図8に示すように、充電曲線と放電曲線との交点における電圧(平均作動電圧)は約3.3Vであったことから、Li2CuSiO4は、高電位及び高容量の正極材料として有用であることが分かった。
From FIG. 7, it was found that the open circuit potential of Li 2 CuSiO 4 was about 3.0V. Further, from FIG. 8, it was found that the initial charge capacity withdrawn at the C / 20 rate was about 110 mAh / g. The theoretical capacity is 316 mAh / g, and the initial charge / discharge capacity of Li 2 CuSiO 4 corresponds to about one third of the theoretical capacity. Further, as shown in FIG. 8, since the voltage (average operating voltage) at the intersection of the charging curve and the discharging curve was about 3.3 V, Li 2 CuSiO 4 was used as a positive electrode material having a high potential and a high capacity. It turned out to be useful.
さらに、図9から、Li2CuSiO4の初回充電容量がC/50レートで220mAh/g (理論容量の約70%に相当する容量)が確認された。このことからも、Li2CuSiO4は高容量材料として期待される。
Furthermore, from FIG. 9, it was confirmed that the initial charge capacity of Li 2 CuSiO 4 was 220 mAh / g (capacity corresponding to about 70% of the theoretical capacity) at the C / 50 rate. Also from this, Li 2 CuSiO 4 is expected as a high capacity material.
また、Li2CuSiO4を用いないこと以外は上記と同様にして正極を作製し、上記と同様の条件によりC/20レートで充放電試験を行った。結果を図10に示す。
Further, a positive electrode was produced in the same manner as described above except that Li 2 CuSiO 4 was not used, and a charge / discharge test was performed at a C / 20 rate under the same conditions as described above. The results are shown in FIG.
図10から、Li2CuSiO4を用いない電極では充放電容量が得られないことが確認された。図8と図10とを比較することにより、図8において示された高い充放電容量は、Li2CuSiO4に由来するものであることが分かった。
From FIG. 10, it was confirmed that charge / discharge capacity could not be obtained with an electrode that did not use Li 2 CuSiO 4 . By comparing FIG. 8 with FIG. 10, it was found that the high charge / discharge capacity shown in FIG. 8 was derived from Li 2 CuSiO 4 .
実施例4:Li 2 CuGeO 4 の充放電特性の測定
充放電測定を行うために、上記実施例2において焼成温度900℃の場合に得られたLi2CuGeO4、ポリフッ化ビニリデン(PVDF)、及びアセチレンブラック(AB)が体積比85:7.5:7.5となるようにめのう乳鉢で混合し、得られたスラリーを正極集電体であるアルミニウム箔(厚さ20μm)上に塗布し、これを直径8mmの円形に打ち抜き、正極とした。また、試料が正極集電体から剥がれないようにするため、30~40mPaで圧着した。 Example 4: Li 2 to make measurements discharge measurements of the charge and discharge characteristics of CuGeO 4, the example Li 2 CuGeO 4 were obtained when the firing temperature 900 ° C. at 2, polyvinylidene fluoride (PVDF), and Acetylene black (AB) was mixed in an agate mortar so that the volume ratio was 85: 7.5: 7.5, and the resulting slurry was applied onto an aluminum foil (thickness 20 μm) as a positive electrode current collector, This was punched into a circle with a diameter of 8 mm to obtain a positive electrode. Further, in order to prevent the sample from being peeled off from the positive electrode current collector, it was pressure-bonded at 30 to 40 mPa.
充放電測定を行うために、上記実施例2において焼成温度900℃の場合に得られたLi2CuGeO4、ポリフッ化ビニリデン(PVDF)、及びアセチレンブラック(AB)が体積比85:7.5:7.5となるようにめのう乳鉢で混合し、得られたスラリーを正極集電体であるアルミニウム箔(厚さ20μm)上に塗布し、これを直径8mmの円形に打ち抜き、正極とした。また、試料が正極集電体から剥がれないようにするため、30~40mPaで圧着した。 Example 4: Li 2 to make measurements discharge measurements of the charge and discharge characteristics of CuGeO 4, the example Li 2 CuGeO 4 were obtained when the firing temperature 900 ° C. at 2, polyvinylidene fluoride (PVDF), and Acetylene black (AB) was mixed in an agate mortar so that the volume ratio was 85: 7.5: 7.5, and the resulting slurry was applied onto an aluminum foil (
負極には14mmφで打ち抜いた金属リチウムを使用し、セパレータは18mmφで切り抜いた多孔質膜(商品名:celgard 2500)を2枚使用した。電解液は、エチレンカーボネート(EC)及びジエチルカーボネート(DEC)を体積比1:2で混合した溶媒に支持電解質としてLiPF6を1mol/dm3の濃度で溶解した電解液(岸田化学社製)を使用した。電池の作製は、金属リチウムを使用すること、及び電解液に水分が混入した場合に抵抗増分増加の要因となること等の理由により、アルゴン雰囲気下のグローブブックス内で行った。セルは、図6に示すCR2032型コインセルを用いた。充放電試験に先立って、電極に電流を印加していない状態の電位(即ち、開回路電位)の測定を行った。定電流充放電測定は、電圧切り替え器を用い、C/50レート、電流10mA/g、上限電圧4.8V、下限電圧1.5Vに設定し、充電より開始した。また、充放電測定は、55℃恒温槽内にセルを入れた状態で行った。開回路電位の測定結果を図11に、充放電特性の測定結果(各サイクルと放電容量との関係)を図12に示す。
Metal lithium punched out at 14 mmφ was used for the negative electrode, and two porous membranes (trade name: celgard 2500) cut out at 18 mmφ were used as the separator. The electrolytic solution is an electrolytic solution (manufactured by Kishida Chemical Co., Ltd.) in which LiPF 6 is dissolved at a concentration of 1 mol / dm 3 as a supporting electrolyte in a solvent in which ethylene carbonate (EC) and diethyl carbonate (DEC) are mixed at a volume ratio of 1: 2. used. The battery was produced in Globe Books under an argon atmosphere because of the use of metallic lithium and the cause of increased resistance when water was mixed in the electrolyte. As the cell, a CR2032-type coin cell shown in FIG. 6 was used. Prior to the charge / discharge test, the potential in a state where no current was applied to the electrode (ie, open circuit potential) was measured. The constant current charge / discharge measurement was started from charging by using a voltage switch, setting a C / 50 rate, a current of 10 mA / g, an upper limit voltage of 4.8 V, and a lower limit voltage of 1.5 V. Moreover, the charge / discharge measurement was performed in a state where the cell was placed in a 55 ° C. constant temperature bath. FIG. 11 shows the measurement result of the open circuit potential, and FIG. 12 shows the measurement result of the charge / discharge characteristics (relationship between each cycle and the discharge capacity).
図11から、Li2CuGeO4の開回路電位は約2.7Vであることが分かった。また、図12から、引き出し初期容量は約120mAh/gであることが分かった。なお、理論容量は250mAh/gであり、Li2CuGeO4の初回充放電容量は理論容量の約2分の1に相当する。以上の結果から、Li2CuGeO4は、高電位及び高容量の正極材料として有用であることが分かった。
From FIG. 11, it was found that the open circuit potential of Li 2 CuGeO 4 was about 2.7V. Also, from FIG. 12, it was found that the initial extraction capacity was about 120 mAh / g. The theoretical capacity is 250 mAh / g, and the initial charge / discharge capacity of Li 2 CuGeO 4 corresponds to about one half of the theoretical capacity. From the above results, it was found that Li 2 CuGeO 4 is useful as a positive electrode material having a high potential and a high capacity.
1 リチウムイオン二次電池
2 負極端子
3 負極
4 電解液が含浸されたセパレータ
5 絶縁パッキング
6 正極
7 正極缶 DESCRIPTION OFSYMBOLS 1 Lithium ion secondary battery 2 Negative electrode terminal 3 Negative electrode 4 Separator impregnated with electrolyte 5 Insulation packing 6 Positive electrode 7 Positive electrode can
2 負極端子
3 負極
4 電解液が含浸されたセパレータ
5 絶縁パッキング
6 正極
7 正極缶 DESCRIPTION OF
Claims (9)
- 組成式(1):
LimCuyX1On
[組成式(1)中、X1はSi又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表されるリチウム銅系複合酸化物。 Composition formula (1):
Li m Cu y X 1 O n
[In the composition formula (1), X 1 represents Si or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
Lithium copper-based composite oxide represented by - 単斜晶構造を有する、請求項1に記載のリチウム銅系複合酸化物。 The lithium copper-based composite oxide according to claim 1, having a monoclinic structure.
- 平均粒子径が0.1~100μmである、請求項1又は2に記載のリチウム銅系複合酸化物。 3. The lithium copper based composite oxide according to claim 1, wherein the average particle size is 0.1 to 100 μm.
- リチウムと、銅と、ケイ素又はゲルマニウムと、酸素とを含む混合物を加熱する工程を含む、請求項1~3のいずれかに記載のリチウム銅系複合酸化物の製造方法。 The method for producing a lithium copper-based composite oxide according to any one of claims 1 to 3, further comprising a step of heating a mixture containing lithium, copper, silicon or germanium, and oxygen.
- 加熱温度が600℃以上である、請求項4に記載の方法。 The method according to claim 4, wherein the heating temperature is 600 ° C. or higher.
- 組成式(2):
LimCuyX2On
[組成式(2)中、X2はSi、Ti又はGeを示す。yは0.8~1.2を示す。mは1.5~2.5を示す。nは3.9~4.1を示す。]
で表されるリチウム銅系複合酸化物を含む、リチウムイオン二次電池用正極活物質。 Composition formula (2):
Li m Cu y X 2 O n
[In the composition formula (2), X 2 represents Si, Ti or Ge. y represents 0.8 to 1.2. m represents 1.5 to 2.5. n represents 3.9 to 4.1. ]
The positive electrode active material for lithium ion secondary batteries containing the lithium copper type complex oxide represented by these. - 請求項6に記載のリチウムイオン二次電池用正極活物質を含む、リチウムイオン二次電池用正極。 The positive electrode for lithium ion secondary batteries containing the positive electrode active material for lithium ion secondary batteries of Claim 6.
- さらに、導電助剤を含む、請求項7に記載のリチウムイオン二次電池用正極。 Furthermore, the positive electrode for lithium ion secondary batteries of Claim 7 containing a conductive support agent.
- 請求項7又は8に記載のリチウムイオン二次電池用正極を含む、リチウムイオン二次電池。 The lithium ion secondary battery containing the positive electrode for lithium ion secondary batteries of Claim 7 or 8.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2017560381A JP6857361B2 (en) | 2016-01-05 | 2017-01-04 | Lithium copper-based composite oxide |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2016-000562 | 2016-01-05 | ||
JP2016000562 | 2016-01-05 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017119410A1 true WO2017119410A1 (en) | 2017-07-13 |
Family
ID=59274196
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2017/000017 WO2017119410A1 (en) | 2016-01-05 | 2017-01-04 | Lithium-copper composite oxide |
Country Status (3)
Country | Link |
---|---|
JP (1) | JP6857361B2 (en) |
TW (1) | TWI790197B (en) |
WO (1) | WO2017119410A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021054621A1 (en) * | 2019-09-20 | 2021-03-25 | 주식회사 엘지화학 | Irreversible additive contained in cathode material for secondary battery, cathode material comprising same, and secondary battery comprising cathode material |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01226729A (en) * | 1988-03-08 | 1989-09-11 | Kubota Ltd | Oxide superconducting material |
JPH09147861A (en) * | 1995-11-22 | 1997-06-06 | Sanyo Electric Co Ltd | Lithium secondary battery |
JP2008293661A (en) * | 2007-05-22 | 2008-12-04 | Nec Tokin Corp | Positive electrode for lithium secondary battery, and lithium secondary battery using it |
JP2010257592A (en) * | 2009-04-21 | 2010-11-11 | Nec Energy Devices Ltd | Lithium ion secondary battery |
CN105457645A (en) * | 2015-12-20 | 2016-04-06 | 桂林理工大学 | Photocatalyst Li2CuGeO4 with visible light response function and preparing method thereof |
-
2017
- 2017-01-04 TW TW106100158A patent/TWI790197B/en active
- 2017-01-04 WO PCT/JP2017/000017 patent/WO2017119410A1/en active Application Filing
- 2017-01-04 JP JP2017560381A patent/JP6857361B2/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01226729A (en) * | 1988-03-08 | 1989-09-11 | Kubota Ltd | Oxide superconducting material |
JPH09147861A (en) * | 1995-11-22 | 1997-06-06 | Sanyo Electric Co Ltd | Lithium secondary battery |
JP2008293661A (en) * | 2007-05-22 | 2008-12-04 | Nec Tokin Corp | Positive electrode for lithium secondary battery, and lithium secondary battery using it |
JP2010257592A (en) * | 2009-04-21 | 2010-11-11 | Nec Energy Devices Ltd | Lithium ion secondary battery |
CN105457645A (en) * | 2015-12-20 | 2016-04-06 | 桂林理工大学 | Photocatalyst Li2CuGeO4 with visible light response function and preparing method thereof |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021054621A1 (en) * | 2019-09-20 | 2021-03-25 | 주식회사 엘지화학 | Irreversible additive contained in cathode material for secondary battery, cathode material comprising same, and secondary battery comprising cathode material |
Also Published As
Publication number | Publication date |
---|---|
JPWO2017119410A1 (en) | 2018-10-25 |
JP6857361B2 (en) | 2021-04-14 |
TW201736269A (en) | 2017-10-16 |
TWI790197B (en) | 2023-01-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6927579B2 (en) | Lithium iron manganese-based composite oxide | |
JP7034471B2 (en) | Potassium compound and positive electrode active material for potassium ion secondary battery containing it | |
US10879533B2 (en) | Nitride- and oxide-modified electrode compositions and their methods of making | |
WO2017099137A1 (en) | Positive electrode active material for potassium ion secondary cell | |
US20120183855A1 (en) | Positive active electrode material for lithium secondary battery, process for preparing the same and lithium secondary battery | |
JP2018085324A (en) | Cathode active material for battery, and battery using cathode active material | |
JPWO2018092359A1 (en) | Positive electrode active material for battery and battery | |
JP7169650B2 (en) | Positive electrode active material for potassium ion secondary battery, manufacturing method thereof, and potassium ion secondary battery | |
CN112054169A (en) | Positive electrode active material and battery | |
WO2020044653A1 (en) | Positive electrode active material and battery provided with same | |
JP7116464B2 (en) | Positive electrode active material for secondary battery, manufacturing method thereof, and secondary battery | |
JP6857361B2 (en) | Lithium copper-based composite oxide | |
JP7016148B2 (en) | Positive electrode active material for potassium ion secondary batteries | |
CN112952081A (en) | Lithium ion battery layered perovskite structure negative electrode material and preparation method thereof | |
WO2017119493A1 (en) | Positive electrode active material for secondary battery, production method therefor, and secondary battery | |
JP2012238554A (en) | Lithium manganese silicate composite, positive electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery | |
JP7060866B2 (en) | A method for manufacturing a positive electrode active material for a secondary battery, a secondary battery, and a positive electrode active material for a secondary battery. | |
JP2003346797A (en) | Non-aqueous electrolyte secondary battery using nickel- lithium compound oxide | |
CN117525386B (en) | High-nickel positive electrode material, and preparation method and application thereof | |
JP2019102198A (en) | Potassium compound, and potassium ion secondary battery cathode active material containing the same | |
WO2023106336A1 (en) | Positive electrode active material for lithium secondary battery, positive electrode for lithium secondary battery, and lithium secondary battery | |
Shang | Optimization of Cathode/Anode Electrode Materials for High Performance Lithium-Ion Batteries | |
JP2023162559A (en) | Lithium composite oxide and method for producing the same | |
CN114944493A (en) | Lithium ion lithium oxygen hybrid battery and preparation method thereof | |
Addu | Facile fabrication of mesostructured Zn2SnO 4 based anode materials for reversible lithium ion storage |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 17735947 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2017560381 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 17735947 Country of ref document: EP Kind code of ref document: A1 |