JP7394336B2 - Negative electrode active material for secondary batteries - Google Patents
Negative electrode active material for secondary batteries Download PDFInfo
- Publication number
- JP7394336B2 JP7394336B2 JP2019155563A JP2019155563A JP7394336B2 JP 7394336 B2 JP7394336 B2 JP 7394336B2 JP 2019155563 A JP2019155563 A JP 2019155563A JP 2019155563 A JP2019155563 A JP 2019155563A JP 7394336 B2 JP7394336 B2 JP 7394336B2
- Authority
- JP
- Japan
- Prior art keywords
- negative electrode
- electrode active
- active material
- secondary battery
- transition metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000007773 negative electrode material Substances 0.000 title claims description 67
- 229910052723 transition metal Inorganic materials 0.000 claims description 71
- -1 transition metal sulfide Chemical class 0.000 claims description 40
- 150000003624 transition metals Chemical class 0.000 claims description 40
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 30
- 229910001415 sodium ion Inorganic materials 0.000 claims description 29
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 claims description 23
- 229910052717 sulfur Inorganic materials 0.000 claims description 23
- 239000011593 sulfur Substances 0.000 claims description 22
- 230000000737 periodic effect Effects 0.000 claims description 20
- 239000002994 raw material Substances 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 15
- 229910052720 vanadium Inorganic materials 0.000 claims description 13
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 12
- 239000006185 dispersion Substances 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 11
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 8
- 238000010438 heat treatment Methods 0.000 claims description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims description 6
- 239000011733 molybdenum Substances 0.000 claims description 6
- 239000000470 constituent Substances 0.000 claims description 4
- 239000011734 sodium Substances 0.000 description 28
- 239000003792 electrolyte Substances 0.000 description 14
- 239000000463 material Substances 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 13
- 238000000034 method Methods 0.000 description 12
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 10
- 238000002441 X-ray diffraction Methods 0.000 description 9
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 8
- 239000011888 foil Substances 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 7
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 7
- 229910001416 lithium ion Inorganic materials 0.000 description 7
- 229910052708 sodium Inorganic materials 0.000 description 7
- 239000010936 titanium Substances 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 239000012153 distilled water Substances 0.000 description 6
- 238000001027 hydrothermal synthesis Methods 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 5
- 239000011230 binding agent Substances 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 5
- 239000011229 interlayer Substances 0.000 description 5
- 239000011244 liquid electrolyte Substances 0.000 description 5
- 229910052744 lithium Inorganic materials 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 229910052976 metal sulfide Inorganic materials 0.000 description 5
- 229910052758 niobium Inorganic materials 0.000 description 5
- 239000010955 niobium Substances 0.000 description 5
- 229910052715 tantalum Inorganic materials 0.000 description 5
- 229910052719 titanium Inorganic materials 0.000 description 5
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 5
- 229910052726 zirconium Inorganic materials 0.000 description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 239000002033 PVDF binder Substances 0.000 description 4
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 239000011651 chromium Substances 0.000 description 4
- SBZXBUIDTXKZTM-UHFFFAOYSA-N diglyme Chemical compound COCCOCCOC SBZXBUIDTXKZTM-UHFFFAOYSA-N 0.000 description 4
- 238000007599 discharging Methods 0.000 description 4
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 4
- 229910052735 hafnium Inorganic materials 0.000 description 4
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 4
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 4
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 4
- 239000007774 positive electrode material Substances 0.000 description 4
- 229910052702 rhenium Inorganic materials 0.000 description 4
- WUAPFZMCVAUBPE-UHFFFAOYSA-N rhenium atom Chemical compound [Re] WUAPFZMCVAUBPE-UHFFFAOYSA-N 0.000 description 4
- PVGBHEUCHKGFQP-UHFFFAOYSA-N sodium;n-[5-amino-2-(4-aminophenyl)sulfonylphenyl]sulfonylacetamide Chemical compound [Na+].CC(=O)NS(=O)(=O)C1=CC(N)=CC=C1S(=O)(=O)C1=CC=C(N)C=C1 PVGBHEUCHKGFQP-UHFFFAOYSA-N 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 4
- YUKQRDCYNOVPGJ-UHFFFAOYSA-N thioacetamide Chemical compound CC(N)=S YUKQRDCYNOVPGJ-UHFFFAOYSA-N 0.000 description 4
- DLFVBJFMPXGRIB-UHFFFAOYSA-N thioacetamide Natural products CC(N)=O DLFVBJFMPXGRIB-UHFFFAOYSA-N 0.000 description 4
- 229910001428 transition metal ion Inorganic materials 0.000 description 4
- 229910052721 tungsten Inorganic materials 0.000 description 4
- 239000010937 tungsten Substances 0.000 description 4
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 3
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- 241001274216 Naso Species 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 3
- 239000004642 Polyimide Substances 0.000 description 3
- KEAYESYHFKHZAL-UHFFFAOYSA-N Sodium Chemical compound [Na] KEAYESYHFKHZAL-UHFFFAOYSA-N 0.000 description 3
- 239000004809 Teflon Substances 0.000 description 3
- 229920006362 Teflon® Polymers 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- 238000005119 centrifugation Methods 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 238000013507 mapping Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000001000 micrograph Methods 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 229920001721 polyimide Polymers 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- 239000007784 solid electrolyte Substances 0.000 description 3
- 239000012265 solid product Substances 0.000 description 3
- 125000004434 sulfur atom Chemical group 0.000 description 3
- 229910052718 tin Inorganic materials 0.000 description 3
- 238000002525 ultrasonication Methods 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 2
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 2
- 229910013684 LiClO 4 Inorganic materials 0.000 description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 2
- 239000011149 active material Substances 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 239000003660 carbonate based solvent Substances 0.000 description 2
- 239000001768 carboxy methyl cellulose Substances 0.000 description 2
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 2
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000006258 conductive agent Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 239000011889 copper foil Substances 0.000 description 2
- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical compound O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 description 2
- 238000002848 electrochemical method Methods 0.000 description 2
- 239000004210 ether based solvent Substances 0.000 description 2
- 239000003365 glass fiber Substances 0.000 description 2
- 229910021389 graphene Inorganic materials 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- JKQOBWVOAYFWKG-UHFFFAOYSA-N molybdenum trioxide Chemical compound O=[Mo](=O)=O JKQOBWVOAYFWKG-UHFFFAOYSA-N 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- RZJRJXONCZWCBN-UHFFFAOYSA-N octadecane Chemical compound CCCCCCCCCCCCCCCCCC RZJRJXONCZWCBN-UHFFFAOYSA-N 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 239000002798 polar solvent Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 2
- 159000000000 sodium salts Chemical class 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 description 2
- YFNKIDBQEZZDLK-UHFFFAOYSA-N triglyme Chemical compound COCCOCCOCCOC YFNKIDBQEZZDLK-UHFFFAOYSA-N 0.000 description 2
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 description 2
- RBORURQQJIQWBS-QVRNUERCSA-N (4ar,6r,7r,7as)-6-(6-amino-8-bromopurin-9-yl)-2-hydroxy-2-sulfanylidene-4a,6,7,7a-tetrahydro-4h-furo[3,2-d][1,3,2]dioxaphosphinin-7-ol Chemical compound C([C@H]1O2)OP(O)(=S)O[C@H]1[C@@H](O)[C@@H]2N1C(N=CN=C2N)=C2N=C1Br RBORURQQJIQWBS-QVRNUERCSA-N 0.000 description 1
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- QGLWBTPVKHMVHM-KTKRTIGZSA-N (z)-octadec-9-en-1-amine Chemical compound CCCCCCCC\C=C/CCCCCCCCN QGLWBTPVKHMVHM-KTKRTIGZSA-N 0.000 description 1
- KPZGRMZPZLOPBS-UHFFFAOYSA-N 1,3-dichloro-2,2-bis(chloromethyl)propane Chemical compound ClCC(CCl)(CCl)CCl KPZGRMZPZLOPBS-UHFFFAOYSA-N 0.000 description 1
- WNXJIVFYUVYPPR-UHFFFAOYSA-N 1,3-dioxolane Chemical compound C1COCO1 WNXJIVFYUVYPPR-UHFFFAOYSA-N 0.000 description 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- 229910015015 LiAsF 6 Inorganic materials 0.000 description 1
- 229910013063 LiBF 4 Inorganic materials 0.000 description 1
- 229910013188 LiBOB Inorganic materials 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 1
- 229910015643 LiMn 2 O 4 Inorganic materials 0.000 description 1
- 229910014689 LiMnO Inorganic materials 0.000 description 1
- 229910013716 LiNi Inorganic materials 0.000 description 1
- 229910002992 LiNi0.33Mn0.33Co0.33O2 Inorganic materials 0.000 description 1
- 229910013290 LiNiO 2 Inorganic materials 0.000 description 1
- 229910012424 LiSO 3 Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
- 229910003249 Na3Zr2Si2PO12 Inorganic materials 0.000 description 1
- 229910020808 NaBF Inorganic materials 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 239000004962 Polyamide-imide Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Natural products NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- HUOSXUVFHUFNTL-UHFFFAOYSA-N [S-2].[S-2].[Mn+4] Chemical compound [S-2].[S-2].[Mn+4] HUOSXUVFHUFNTL-UHFFFAOYSA-N 0.000 description 1
- UDKXBPLHYDCWIG-UHFFFAOYSA-M [S-2].[S-2].[SH-].S.[V+5] Chemical compound [S-2].[S-2].[SH-].S.[V+5] UDKXBPLHYDCWIG-UHFFFAOYSA-M 0.000 description 1
- APUPEJJSWDHEBO-UHFFFAOYSA-P ammonium molybdate Chemical compound [NH4+].[NH4+].[O-][Mo]([O-])(=O)=O APUPEJJSWDHEBO-UHFFFAOYSA-P 0.000 description 1
- 235000018660 ammonium molybdate Nutrition 0.000 description 1
- 239000011609 ammonium molybdate Substances 0.000 description 1
- 229940010552 ammonium molybdate Drugs 0.000 description 1
- UYJXRRSPUVSSMN-UHFFFAOYSA-P ammonium sulfide Chemical compound [NH4+].[NH4+].[S-2] UYJXRRSPUVSSMN-UHFFFAOYSA-P 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
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 description 1
- WVMYSOZCZHQCSG-UHFFFAOYSA-N bis(sulfanylidene)zirconium Chemical compound S=[Zr]=S WVMYSOZCZHQCSG-UHFFFAOYSA-N 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000002800 charge carrier Substances 0.000 description 1
- DBULDCSVZCUQIR-UHFFFAOYSA-N chromium(3+);trisulfide Chemical compound [S-2].[S-2].[S-2].[Cr+3].[Cr+3] DBULDCSVZCUQIR-UHFFFAOYSA-N 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- BNBLBRISEAQIHU-UHFFFAOYSA-N disodium dioxido(dioxo)manganese Chemical compound [Na+].[Na+].[O-][Mn]([O-])(=O)=O BNBLBRISEAQIHU-UHFFFAOYSA-N 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910021469 graphitizable carbon Inorganic materials 0.000 description 1
- NRJVMVHUISHHQB-UHFFFAOYSA-N hafnium(4+);disulfide Chemical compound [S-2].[S-2].[Hf+4] NRJVMVHUISHHQB-UHFFFAOYSA-N 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 229910000664 lithium aluminum titanium phosphates (LATP) Inorganic materials 0.000 description 1
- DEUISMFZZMAAOJ-UHFFFAOYSA-N lithium dihydrogen borate oxalic acid Chemical compound B([O-])(O)O.C(C(=O)O)(=O)O.C(C(=O)O)(=O)O.[Li+] DEUISMFZZMAAOJ-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
- 229910003002 lithium salt Inorganic materials 0.000 description 1
- 159000000002 lithium salts Chemical class 0.000 description 1
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 239000008204 material by function Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- GICWIDZXWJGTCI-UHFFFAOYSA-I molybdenum pentachloride Chemical compound Cl[Mo](Cl)(Cl)(Cl)Cl GICWIDZXWJGTCI-UHFFFAOYSA-I 0.000 description 1
- YKYONYBAUNKHLG-UHFFFAOYSA-N n-Propyl acetate Natural products CCCOC(C)=O YKYONYBAUNKHLG-UHFFFAOYSA-N 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 229910021470 non-graphitizable carbon Inorganic materials 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 229940038384 octadecane Drugs 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920002312 polyamide-imide Polymers 0.000 description 1
- 229920000573 polyethylene 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
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 1
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 1
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000000634 powder X-ray diffraction Methods 0.000 description 1
- 229940090181 propyl acetate Drugs 0.000 description 1
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 1
- USBWXQYIYZPMMN-UHFFFAOYSA-N rhenium;heptasulfide Chemical compound [S-2].[S-2].[S-2].[S-2].[S-2].[S-2].[S-2].[Re].[Re] USBWXQYIYZPMMN-UHFFFAOYSA-N 0.000 description 1
- PXLIDIMHPNPGMH-UHFFFAOYSA-N sodium chromate Chemical compound [Na+].[Na+].[O-][Cr]([O-])(=O)=O PXLIDIMHPNPGMH-UHFFFAOYSA-N 0.000 description 1
- GROMGGTZECPEKN-UHFFFAOYSA-N sodium metatitanate Chemical compound [Na+].[Na+].[O-][Ti](=O)O[Ti](=O)O[Ti]([O-])=O GROMGGTZECPEKN-UHFFFAOYSA-N 0.000 description 1
- 235000015393 sodium molybdate Nutrition 0.000 description 1
- 239000011684 sodium molybdate Substances 0.000 description 1
- TVXXNOYZHKPKGW-UHFFFAOYSA-N sodium molybdate (anhydrous) Chemical compound [Na+].[Na+].[O-][Mo]([O-])(=O)=O TVXXNOYZHKPKGW-UHFFFAOYSA-N 0.000 description 1
- BAZAXWOYCMUHIX-UHFFFAOYSA-M sodium perchlorate Chemical compound [Na+].[O-]Cl(=O)(=O)=O BAZAXWOYCMUHIX-UHFFFAOYSA-M 0.000 description 1
- 229910001488 sodium perchlorate Inorganic materials 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- XMVONEAAOPAGAO-UHFFFAOYSA-N sodium tungstate Chemical compound [Na+].[Na+].[O-][W]([O-])(=O)=O XMVONEAAOPAGAO-UHFFFAOYSA-N 0.000 description 1
- YLKTWKVVQDCJFL-UHFFFAOYSA-N sodium;bis(trifluoromethylsulfonyl)azanide Chemical compound [Na+].FC(F)(F)S(=O)(=O)[N-]S(=O)(=O)C(F)(F)F YLKTWKVVQDCJFL-UHFFFAOYSA-N 0.000 description 1
- UYLYBEXRJGPQSH-UHFFFAOYSA-N sodium;oxido(dioxo)niobium Chemical compound [Na+].[O-][Nb](=O)=O UYLYBEXRJGPQSH-UHFFFAOYSA-N 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 229920001935 styrene-ethylene-butadiene-styrene Polymers 0.000 description 1
- CADICXFYUNYKGD-UHFFFAOYSA-N sulfanylidenemanganese Chemical compound [Mn]=S CADICXFYUNYKGD-UHFFFAOYSA-N 0.000 description 1
- NYPFJVOIAWPAAV-UHFFFAOYSA-N sulfanylideneniobium Chemical compound [Nb]=S NYPFJVOIAWPAAV-UHFFFAOYSA-N 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- FAWYJKSBSAKOFP-UHFFFAOYSA-N tantalum(iv) sulfide Chemical compound S=[Ta]=S FAWYJKSBSAKOFP-UHFFFAOYSA-N 0.000 description 1
- CFJRPNFOLVDFMJ-UHFFFAOYSA-N titanium disulfide Chemical compound S=[Ti]=S CFJRPNFOLVDFMJ-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
- IHIXIJGXTJIKRB-UHFFFAOYSA-N trisodium vanadate Chemical compound [Na+].[Na+].[Na+].[O-][V]([O-])([O-])=O IHIXIJGXTJIKRB-UHFFFAOYSA-N 0.000 description 1
- ITRNXVSDJBHYNJ-UHFFFAOYSA-N tungsten disulfide Chemical compound S=[W]=S ITRNXVSDJBHYNJ-UHFFFAOYSA-N 0.000 description 1
- NQPDZGIKBAWPEJ-UHFFFAOYSA-N valeric acid Chemical compound CCCCC(O)=O NQPDZGIKBAWPEJ-UHFFFAOYSA-N 0.000 description 1
- 229910009161 xLi2S-(1-x)P2S5 Inorganic materials 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Battery Electrode And Active Subsutance (AREA)
Description
本発明は、二次電池用負極活物質に関する。 The present invention relates to a negative electrode active material for secondary batteries.
二次電池のなかで最も高いエネルギー密度を有するリチウムイオン二次電池が実用化されているが、その代替技術の一つが電荷担体をリチウムイオンからより資源的に豊富なナトリウムイオンに代えたナトリウムイオン二次電池である。ナトリウムイオン二次電池は、リチウムイオン二次電池と同様に高い作動電圧（3V以上）を実現できることが有望視される二次電池の一つである。 Lithium ion secondary batteries, which have the highest energy density among secondary batteries, are in practical use, but one alternative technology is sodium ion, which replaces lithium ions as charge carriers with sodium ions, which are more abundant in resources. It is a secondary battery. Sodium ion secondary batteries are one of the promising secondary batteries that can achieve high operating voltages (3V or higher) like lithium ion secondary batteries.
このナトリウムイオン二次電池用負極活物質としては、二次元層状構造を有する金属硫化物（MS2）が、大きな層間隔に伴う優れたナトリウムイオンの取り込み能力を有することから期待されている。しかしながら、ナトリウム挿入時及び脱離時の体積変化や低い導電性等の問題から、二次元層状構造を有する金属硫化物は十分な充放電容量を発揮できず、充放電サイクル特性が特に悪い。これらの問題を克服するため、二次元層状構造を有する金属硫化物及び他の導電材料からなるナノ材料等が注目されている。 Metal sulfide (MS 2 ) having a two-dimensional layered structure is expected to be used as a negative electrode active material for sodium ion secondary batteries because it has an excellent ability to take in sodium ions due to its large interlayer spacing. However, due to problems such as volume changes during sodium insertion and desorption and low conductivity, metal sulfides having a two-dimensional layered structure cannot exhibit sufficient charge and discharge capacity, and have particularly poor charge and discharge cycle characteristics. To overcome these problems, nanomaterials made of metal sulfides and other conductive materials with a two-dimensional layered structure are attracting attention.
このようなナノ材料の実例として、電気化学的に活性なMoS2と、導電性及び電気化学活性を併せ持った炭素との複合材料として、非特許文献１には、MoS2－グラフェン複合三次元マイクロ球体材料が記載されており、非特許文献２には、炭素とMoS2との交互積層構造を持つ中空ナノ粒子が記載されている。 As an example of such a nanomaterial, Non-Patent Document 1 describes a composite material of MoS 2 that is electrochemically active and carbon that has both conductivity and electrochemical activity. A spherical material is described, and in Non-Patent Document 2, hollow nanoparticles having an alternating layered structure of carbon and MoS 2 are described.
しかしながら、上記した従来の材料の合成には複雑な手順と高温での焼成が必要な点が難点である。したがって、優れた性能を示すナトリウムイオン二次電池用の負極活物質の簡便な合成法の開発は重要である。 However, the synthesis of the conventional materials described above requires complicated procedures and high-temperature firing. Therefore, it is important to develop a simple synthesis method for negative electrode active materials for sodium ion secondary batteries that exhibit excellent performance.
以上から、本発明は、充放電サイクル特性に優れ、簡便な方法で合成することが可能な二次電池用負極活物質を提供することを目的とする。 In view of the above, an object of the present invention is to provide a negative electrode active material for a secondary battery that has excellent charge-discharge cycle characteristics and can be synthesized by a simple method.
本発明者らは、上記した目的を達成すべく鋭意研究を重ねてきた。その結果、周期表第4族～第7族に属する少なくとも2種の遷移金属と、硫黄とを構成元素として含み、二次元層状構造を有する硫化物が、充放電サイクル特性に優れ、且つ、原料となる分散液を加熱する水熱合成法により簡便に合成することができることを見出した。本発明は、このような知見に基づき、さらに研究を重ね、完成されたものである。即ち、本発明は、以下の構成を包含する。
項１．周期表第4族～第7族及び第14族に属する少なくとも2種の遷移金属と、硫黄とを構成元素として含み、
二次元層状構造を有する遷移金属硫化物を含有する、二次電池用負極活物質。
項２．前記遷移金属が、チタン、モリブデン、タングステン、ジルコニウム、ハフニウム、バナジウム、ニオブ、タンタル、レニウム及びスズよりなる群から選ばれる少なくとも2種の遷移金属を含む、項１に記載の二次電池用負極活物質。
項３．前記遷移金属が、周期表第5族に属する少なくとも1種の遷移金属と、周期表第6族に属する少なくとも1種の遷移金属とを含む、項１又は２に記載の二次電池用負極活物質。
項４．前記遷移金属硫化物が、一般式（1）：
M1
xM2
1-xSy （1）
［式中、M1及びM2は異なって、周期表第4族～第7族に属する少なくとも1種の遷移金属を示す。xは0.1～0.9を示す。yは1.5～3.0を示す。］
で表される組成を有する、項１～３のいずれか１項に記載の二次電池用負極活物質。
項５．前記遷移金属硫化物が、CuKα線によるＸ線回折図における回折角2θ= 10°～80°の範囲内において、±1.0°の許容範囲で、少なくとも、14.8°、32.8°、39.2°及び58.1°にピークを有する、項１～４のいずれか１項に記載の二次電池用負極活物質。
項６．ナトリウムイオン二次電池用負極活物質である、項１～５のいずれか１項に記載の二次電池用負極活物質。
項７．項１～６のいずれか１項に記載の二次電池用負極活物質の製造方法であって、
周期表第4族～第7族及び第14族に属する少なくとも2種の遷移金属及び硫黄を含む原料混合物の分散液を100～400℃に加熱する工程
を備える、製造方法。
項８．項１～６のいずれか１項に記載の二次電池用負極活物質を含有する、二次電池用負極。
項９．ナトリウムイオン二次電池用負極である、項８に記載の二次電池用負極。
項１０．項８又は９に記載の二次電池用負極を備える、二次電池。
項１１．ナトリウムイオン二次電池である、項１０に記載の二次電池。
The present inventors have conducted extensive research in order to achieve the above-mentioned objective. As a result, a sulfide containing at least two transition metals belonging to Groups 4 to 7 of the periodic table and sulfur as constituent elements and having a two-dimensional layered structure has excellent charge-discharge cycle characteristics and can be used as a raw material. We have found that it can be easily synthesized by a hydrothermal synthesis method in which a dispersion liquid is heated. The present invention was completed based on such knowledge and further research. That is, the present invention includes the following configurations.
Item 1. Containing at least two transition metals belonging to Groups 4 to 7 and 14 of the periodic table and sulfur as constituent elements,
A negative electrode active material for secondary batteries containing a transition metal sulfide having a two-dimensional layered structure.
Item 2. Item 2. The negative electrode active for secondary batteries according to Item 1, wherein the transition metal includes at least two transition metals selected from the group consisting of titanium, molybdenum, tungsten, zirconium, hafnium, vanadium, niobium, tantalum, rhenium, and tin. material.
Item 3. Item 2. The negative electrode active for secondary batteries according to Item 1 or 2, wherein the transition metal includes at least one transition metal belonging to Group 5 of the periodic table and at least one transition metal belonging to Group 6 of the periodic table. material.
Item 4. The transition metal sulfide has general formula (1):
M 1 x M 2 1-x S y (1)
[In the formula, M 1 and M 2 are different and represent at least one transition metal belonging to Groups 4 to 7 of the periodic table. x indicates 0.1 to 0.9. y indicates 1.5 to 3.0. ]
The negative electrode active material for secondary batteries according to any one of Items 1 to 3, having a composition represented by:
Item 5. The transition metal sulfide has a diffraction angle of at least 14.8°, 32.8°, 39.2°, and 58.1° within a range of diffraction angle 2θ = 10° to 80° in an X-ray diffraction diagram using CuKα rays, within a tolerance range of ±1.0°. The negative electrode active material for secondary batteries according to any one of Items 1 to 4, which has a peak at .
Item 6. The negative electrode active material for a secondary battery according to any one of Items 1 to 5, which is a negative electrode active material for a sodium ion secondary battery.
Section 7. A method for producing a negative electrode active material for a secondary battery according to any one of items 1 to 6, comprising:
A manufacturing method comprising the step of heating a dispersion of a raw material mixture containing at least two transition metals belonging to Groups 4 to 7 and 14 of the periodic table and sulfur to 100 to 400°C.
Section 8. A negative electrode for a secondary battery, comprising the negative electrode active material for a secondary battery according to any one of items 1 to 6.
Item 9. Item 8. The negative electrode for a secondary battery according to item 8, which is a negative electrode for a sodium ion secondary battery.
Item 10. A secondary battery comprising the negative electrode for a secondary battery according to item 8 or 9.
Item 11. Item 11. The secondary battery according to item 10, which is a sodium ion secondary battery.
本発明によれば、充放電サイクル特性に優れ、簡便な方法で合成することが可能な二次電池用負極活物質を提供することができる。 According to the present invention, it is possible to provide a negative electrode active material for a secondary battery that has excellent charge-discharge cycle characteristics and can be synthesized by a simple method.
本明細書において、「含有」は、「含む（comprise）」、「実質的にのみからなる（consist essentially of）」、及び「のみからなる（consist of）」のいずれも包含する概念である。 In this specification, "contain" is a concept that includes all of "comprise," "consist essentially of," and "consist of."
また、本明細書において、「Ａ～Ｂ」との表記は、「Ａ以上且つＢ以下」を意味する。 In addition, in this specification, the expression "A to B" means "more than or equal to A and less than or equal to B."
１．二次電池用負極活物質
本発明の二次電池用負極活物質は、周期表第4族～第7族及び第14族に属する少なくとも2種の遷移金属と、硫黄とを構成元素として含み、二次元層状構造を有する遷移金属硫化物を含有する。
1. Negative electrode active material for secondary batteries The negative electrode active material for secondary batteries of the present invention contains at least two transition metals belonging to Groups 4 to 7 and 14 of the periodic table and sulfur as constituent elements, Contains transition metal sulfides with a two-dimensional layered structure.
このように、本発明においては、周期表第4族～第7族及び第14族に属する少なくとも2種の遷移金属を有する遷移金属硫化物を含有することにより、充放電サイクル特性に優れる二次電池用負極活物質とすることができる。 As described above, in the present invention, by containing a transition metal sulfide containing at least two types of transition metals belonging to Groups 4 to 7 and 14 of the periodic table, secondary It can be used as a negative electrode active material for batteries.
周期表第4族～第7族及び第14族に属する遷移金属としては、特に制限はなく、周期表第4族に属する遷移金属としてチタン、ジルコニウム、ハフニウム等が挙げられ、周期表第5族に属する遷移金属としてバナジウム、ニオブ、タンタル等が挙げられ、周期表第6族に属する遷移金属としてクロム、モリブデン、タングステン等が挙げられ、周期表第7族に属する遷移金属としてマンガン、レニウム等が挙げられ、周期表第14族に属する遷移金属としてスズ、鉛等が挙げられる。本発明の二次電池用負極活物質においては、遷移金属硫化物は、これらの遷移金属のなかから2種以上を組合せて含有している。なかでも、充放電サイクル特性に優れる観点からチタン、モリブデン、タングステン、ジルコニウム、ハフニウム、バナジウム、ニオブ、タンタル、レニウム、スズ等が好ましい。また、多くの欠陥と空孔が形成され層間間隔も拡大できる組合せが好ましく、充放電サイクル特性に優れる観点から、遷移金属硫化物は周期表第5族に属する少なくとも1種の遷移金属と、周期表第6族に属する少なくとも1種の遷移金属とを含むことが好ましい。 There are no particular restrictions on the transition metals belonging to Groups 4 to 7 and 14 of the periodic table, and examples of transition metals belonging to Group 4 of the periodic table include titanium, zirconium, hafnium, etc., and transition metals belonging to Group 5 of the periodic table. Transition metals that belong to Group 6 of the periodic table include vanadium, niobium, tantalum, etc. Transition metals that belong to Group 6 of the periodic table include chromium, molybdenum, tungsten, etc. Transition metals that belong to Group 7 of the periodic table include manganese, rhenium, etc. Examples of transition metals belonging to Group 14 of the periodic table include tin and lead. In the negative electrode active material for a secondary battery of the present invention, the transition metal sulfide contains a combination of two or more of these transition metals. Among these, titanium, molybdenum, tungsten, zirconium, hafnium, vanadium, niobium, tantalum, rhenium, tin, and the like are preferred from the viewpoint of excellent charge-discharge cycle characteristics. In addition, a combination in which many defects and vacancies are formed and the interlayer spacing can be expanded is preferable, and from the viewpoint of excellent charge-discharge cycle characteristics, the transition metal sulfide is a combination of at least one transition metal belonging to Group 5 of the periodic table and a periodic At least one transition metal belonging to Group 6 in the table is preferably included.
より詳細には、本発明の二次電池用負極活物質が含有する遷移金属硫化物は、一般式（1）：
M1
xM2
1-xSy （1）
［式中、M1及びM2は異なって、周期表第4族～第7族に属する少なくとも1種の遷移金属を示す。xは0.1～0.9を示す。yは1.5～3.0を示す。］
で表される組成を有することが好ましい。
More specifically, the transition metal sulfide contained in the negative electrode active material for secondary batteries of the present invention has the general formula (1):
M 1 x M 2 1-x S y (1)
[In the formula, M 1 and M 2 are different and represent at least one transition metal belonging to Groups 4 to 7 of the periodic table. x indicates 0.1 to 0.9. y indicates 1.5 to 3.0. ]
It is preferable to have a composition represented by:
なお、本発明では、M1及びM2の含有量（x値）を適度な範囲に調整することで、充放電サイクル特性を特に向上させることができる。このため、xは0.1～0.9が好ましく、0.2～0.8がより好ましく、0.3～0.7がさらに好ましい。 In addition, in the present invention, the charge/discharge cycle characteristics can be particularly improved by adjusting the content (x value) of M 1 and M 2 within an appropriate range. Therefore, x is preferably 0.1 to 0.9, more preferably 0.2 to 0.8, and even more preferably 0.3 to 0.7.
また、本発明では、Sの含有量（y値）を適度な範囲に調整することで、充放電サイクル特性を特に向上させることができる。このため、yとしては1.5～2.5が好ましく、1.6～2.4がより好ましく、1.7～2.3が特に好ましい。 Further, in the present invention, the charge/discharge cycle characteristics can be particularly improved by adjusting the S content (y value) to an appropriate range. Therefore, y is preferably 1.5 to 2.5, more preferably 1.6 to 2.4, and particularly preferably 1.7 to 2.3.
本発明の二次電池用負極活物質が含有する遷移金属硫化物は、二次元層状構造を有することが好ましい。特に、1種の遷移金属イオンが他の遷移金属硫化物の構造にドープされた二次元層状構造を有するバイメタル層状硫化物とすることで、材料形成中に多くの欠陥と空孔が形成され、層間間隔も拡大することでより多くのナトリウムイオンを収容して容量が向上するとともに、充放電サイクル特性もより向上することができる。 It is preferable that the transition metal sulfide contained in the negative electrode active material for a secondary battery of the present invention has a two-dimensional layered structure. In particular, by forming a bimetallic layered sulfide with a two-dimensional layered structure in which one type of transition metal ion is doped into the structure of another transition metal sulfide, many defects and pores are formed during material formation. By enlarging the interlayer spacing, more sodium ions can be accommodated to improve the capacity, and the charge/discharge cycle characteristics can also be further improved.
より具体的には、本発明の二次電池用負極活物質が含有する遷移金属硫化物は、CuKα線によるＸ線回折図における回折角2θ= 10°～80°の範囲内において、±1.0°の許容範囲（好ましくは±0.5°の許容範囲）で、少なくとも、14.8°、32.8°、39.2°及び58.1°にピークを有することが好ましい。つまり、13.8°～15.8°、31.8°～33.8°、38.2°～40.2°、及び57.1°～59.1°の範囲（好ましくは14.3°～15.3°、32.3°～33.3°、38.7°～39.7°、及び57.6°～58.6°の範囲）にピークを有することが好ましい。 More specifically, the transition metal sulfide contained in the negative electrode active material for secondary batteries of the present invention has a diffraction angle of ±1.0° within the range of diffraction angle 2θ = 10° to 80° in an X-ray diffraction diagram using CuKα rays. It is preferable to have peaks at least at 14.8°, 32.8°, 39.2° and 58.1° within a tolerance range (preferably a tolerance range of ±0.5°). That is, the ranges of 13.8° to 15.8°, 31.8° to 33.8°, 38.2° to 40.2°, and 57.1° to 59.1° (preferably 14.3° to 15.3°, 32.3° to 33.3°, 38.7° to 39.7°, and It is preferable to have a peak in the range of 57.6° to 58.6°).
なお、本発明において、Ｘ線回折図は、粉末Ｘ線回折測定法によって求められるものであり、例えば、以下の測定条件：
測定装置: Rigaku SmartLab X-ray Diffractometer
Ｘ線源：CuKα 45kV/200mA
測定条件：2θ= 10°～80°、0.01°ステップ、走査速度10°/分
で測定することができる。
In the present invention, the X-ray diffraction pattern is obtained by powder X-ray diffraction measurement method, for example, under the following measurement conditions:
Measurement device: Rigaku SmartLab X-ray Diffractometer
X-ray source: CuKα 45kV/200mA
Measurement conditions: 2θ = 10° to 80°, 0.01° step, scanning speed 10°/min.
本発明の二次電池用負極活物質が含有する遷移金属硫化物は、2種類以上存在する遷移金属原子と硫黄原子との間に結合が形成されており、硫黄は単体硫黄としてはほとんど存在しないために副生成物の形成が抑制され、遷移金属を1種類しか含有しない遷移金属硫化物と比較すると、遷移金属及び硫黄間の結合が増えたことで、充放電に伴う硫黄原子の溶出や、硫黄原子由来の副生成物の形成を抑制し、可逆的に充放電が進行し、充放電サイクル特性を向上させることができる。 In the transition metal sulfide contained in the negative electrode active material for secondary batteries of the present invention, a bond is formed between two or more types of transition metal atoms and a sulfur atom, and sulfur hardly exists as an elemental sulfur. As a result, the formation of by-products is suppressed, and compared to transition metal sulfides that contain only one type of transition metal, the number of bonds between transition metals and sulfur increases, resulting in less elution of sulfur atoms during charge and discharge, The formation of byproducts derived from sulfur atoms is suppressed, charge and discharge proceed reversibly, and charge and discharge cycle characteristics can be improved.
本発明の二次電池用負極活物質が含有する遷移金属硫化物においては、±1.0°の許容範囲（好ましくは±0.5°の許容範囲）で2θ= 58.1°（具体的には57.1°～59.1°、特に57.6°～58.6°）のピークの半値全幅が0.1～2.0°（特に0.2～1.0°）が好ましい。このように、本発明の二次電池用負極活物質が含有する遷移金属硫化物は、±1.0°の許容範囲（好ましくは±0.5°の許容範囲）で2θ= 58.1°のピークの半値全幅が、遷移金属を1種類しか含有しない遷移金属硫化物（例えば硫化モリブデンMoS2等）と比較すると小さいことが好ましい。このように、本発明においては高結晶性であることにより、初期充放電容量及び充放電サイクル特性を向上させることができる。 In the transition metal sulfide contained in the negative electrode active material for secondary batteries of the present invention, 2θ=58.1° (specifically, 57.1° to 59.1°) within a tolerance range of ±1.0° (preferably a tolerance range of ±0.5°). The full width at half maximum of the peak at 0.1° to 2.0° (especially 0.2° to 1.0°) is preferable. As described above, the transition metal sulfide contained in the negative electrode active material for secondary batteries of the present invention has a full width at half maximum of the peak at 2θ = 58.1° within a tolerance range of ±1.0° (preferably a tolerance range of ±0.5°). , is preferably smaller than a transition metal sulfide containing only one type of transition metal (for example, molybdenum sulfide MoS 2 etc.). As described above, in the present invention, by having high crystallinity, initial charge/discharge capacity and charge/discharge cycle characteristics can be improved.
また、単体硫黄等を多量に含む材料を負極活物質として用いた場合には、カーボネート系溶媒は単体硫黄と反応を起こすうえに、エーテル系溶媒は硫黄成分を大量に溶解させるために性能悪化を引起こすために溶媒選択の幅が狭かった。これに対して、本発明の二次電池用負極活物質が含有する遷移金属硫化物は単体硫黄等をほとんど含んでいないため、負極活物質として使用する場合には、カーボネート系溶媒、エーテル系溶媒を用いた場合にもこれらの問題は生じず、電解液用の溶媒の選択性を向上させることができる。 Furthermore, when a material containing a large amount of elemental sulfur is used as a negative electrode active material, carbonate-based solvents react with elemental sulfur, and ether-based solvents dissolve a large amount of sulfur components, resulting in performance deterioration. The range of solvents to choose from was narrow. On the other hand, the transition metal sulfide contained in the negative electrode active material for secondary batteries of the present invention contains almost no elemental sulfur, so when used as a negative electrode active material, carbonate-based solvents, ether-based solvents, etc. These problems do not occur even when using the above method, and the selectivity of the solvent for the electrolytic solution can be improved.
より具体的には、硫黄（S8）の最も強いピークは、±1.0°の許容範囲（好ましくは±0.5°の許容範囲）で、2θ= 23.0°に存在する。このことから、CuKα線によるＸ線回折図において、±1.0°の許容範囲（好ましくは±0.5°の許容範囲）で、単体硫黄に特徴的なピークである、2θ= 23.0°に極大を有するピークを有さないことが好ましい。これにより、本発明の二次電池用負極活物質が含有する遷移金属硫化物において、単体硫黄をほとんど含まない材料とすることができ、上記のような電解液との反応を起こす懸念をより少なくし、初期充放電容量及び充放電サイクル特性をより向上させることができる。 More specifically, the strongest peak of sulfur (S 8 ) is present at 2θ=23.0°, with a tolerance of ±1.0° (preferably a tolerance of ±0.5°). From this, in the X-ray diffraction diagram using CuKα rays, within a tolerance range of ±1.0° (preferably a tolerance range of ±0.5°), a peak with a maximum at 2θ = 23.0°, which is a characteristic peak of elemental sulfur, can be detected. It is preferable not to have. As a result, the transition metal sulfide contained in the negative electrode active material for secondary batteries of the present invention can be made into a material that contains almost no elemental sulfur, and there is less concern that it will react with the electrolyte as described above. However, the initial charge/discharge capacity and charge/discharge cycle characteristics can be further improved.
本発明の二次電池用負極活物質が含有する遷移金属硫化物は、他にも、±1.0°の許容範囲（好ましくは±0.5°の許容範囲）で、単体硫黄に特徴的なピークである2θ= 25.8°及び27.8°の位置についても、ピークを有さないことが好ましい。これにより、本発明の二次電池用負極活物質が含有する遷移金属硫化物において、単体硫黄をほとんど含まない材料とすることができ、上記のような電解液との反応を起こす懸念をより少なくし、初期充放電容量及び充放電サイクル特性をより向上させることができる。 The transition metal sulfide contained in the negative electrode active material for secondary batteries of the present invention also has a peak characteristic of elemental sulfur within a tolerance range of ±1.0° (preferably a tolerance range of ±0.5°). It is also preferable that there be no peaks at the positions of 2θ=25.8° and 27.8°. As a result, the transition metal sulfide contained in the negative electrode active material for secondary batteries of the present invention can be made into a material that contains almost no elemental sulfur, and there is less concern that it will react with the electrolyte as described above. However, the initial charge/discharge capacity and charge/discharge cycle characteristics can be further improved.
なお、本発明の二次電池用負極活物質は、その性能を阻害しない範囲であれば、その他の不純物も含まれ得る。このような不純物としては、後述の製造方法における原料や原料に混入する可能性のある遷移金属、酸素等を例示できる。 Note that the negative electrode active material for a secondary battery of the present invention may also contain other impurities as long as they do not impair its performance. Examples of such impurities include transition metals, oxygen, etc. that may be mixed into raw materials or raw materials in the manufacturing method described below.
これらの不純物の量については、上記した本発明の二次電池用負極活物質の性能を阻害しない範囲が好ましく、本発明の二次電池用負極活物質の総量を100質量%として、通常、2質量%以下（0～2質量%）が好ましく、1.5質量%以下（0～1.5質量%）がより好ましい。ただし、不純物としては、上記したように、単体硫黄は極力含まないことが好ましい。 The amount of these impurities is preferably in a range that does not impede the performance of the negative electrode active material for secondary batteries of the present invention described above, and usually 2 It is preferably at most 1.5% by mass (0 to 1.5% by mass), more preferably at most 1.5% by mass (0 to 1.5% by mass). However, as described above, it is preferable that elemental sulfur is not included as much as possible as an impurity.
以上のように、本発明の二次電池用負極活物質は、初期容量が十分に高く、充放電サイクル特性を向上させることができることから、二次電池用負極活物質（特にナトリウムイオン二次電池用負極活物質、リチウムイオン二次電池用負極活物質等）として有用である。 As described above, the negative electrode active material for secondary batteries of the present invention has a sufficiently high initial capacity and can improve charge/discharge cycle characteristics. It is useful as a negative electrode active material for lithium ion secondary batteries, a negative electrode active material for lithium ion secondary batteries, etc.
２．二次電池用負極活物質の製造方法
本発明の二次電池用負極活物質は、
周期表第4族～第7族及び第14族に属する少なくとも2種の遷移金属及び硫黄を含む原料混合物の分散液を100～400℃に加熱する工程
を備える製造方法によって得ることができる。
2. Method for producing negative electrode active material for secondary batteries The negative electrode active material for secondary batteries of the present invention is
It can be obtained by a production method comprising a step of heating a dispersion of a raw material mixture containing at least two transition metals belonging to Groups 4 to 7 and 14 of the periodic table and sulfur to 100 to 400°C.
原料混合物中に含まれる具体的な原料としては、遷移金属としてチタンを含ませる場合は二硫化チタンTiS2、チタン酸ナトリウムNa2Ti3O7、四塩化チタンTiCl4等が挙げられ、遷移金属としてジルコニウムを含ませる場合は硫化ジルコニウムZrS2、ジルコン酸ナトリウムNa2ZrO3等が挙げられ、遷移金属としてハフニウムを含ませる場合は硫化ハフニウムHfS2等が挙げられ、遷移金属としてバナジウムを含ませる場合は三硫化二バナジウムV2S3、四硫化バナジウムVS4、メタバナジン酸アンモニウムNH4VO3、オルトバナジン酸ナトリウムNa3VO4、メタバナジン酸ナトリウムNaVO3、五酸化二バナジウムV2O5、四塩化バナジウムVCl4、モントロサイトVOOH等が挙げられ、遷移金属としてニオブを含ませる場合は硫化ニオブNbS2、ニオブ酸ナトリウムNaNbO3等が挙げられ、遷移金属としてタンタルを含ませる場合は硫化タンタルTaS2、タンタル酸ナトリウムNaTaO3等が挙げられ、遷移金属としてクロムを含ませる場合は硫化クロムCr2S3、クロム酸ナトリウムNa2CrO4、二クロム酸ナトリウムNa2Cr2O7等が挙げられ、遷移金属としてモリブデンを含ませる場合は硫化モリブデンMoS2、モリブデン酸ナトリウムNa2MoO4、モリブデン酸アンモニウム(NH4)2MoO4、三酸化モリブデンMoO3、五塩化モリブデンMoCl5等が挙げられ、遷移金属としてタングステンを含ませる場合は硫化タングステンWS2、タングステン酸ナトリウムNa2WO4、タングステン酸アンモニウム(NH4)2WO4、三酸化タングステンWO3等が挙げられ、遷移金属としてマンガンを含ませる場合は硫化マンガンMnS、二硫化マンガンMnS2、マンガン酸ナトリウムNa2MnO4等が挙げられ、遷移金属としてレニウムを含ませる場合は硫化レニウムReS2、過レニウム酸アンモニウムNH4ReO4、メタ過レニウム酸ナトリウムNaReO4等が挙げられる。これらの原料化合物は、特に限定はなく、公知又は市販品を用いることができる。特に、高純度のものを用いることが好ましい。なお、使用する原料化合物の形態も特に制限はないものの、分散液を水熱合成するため、粉末状のものを用いることが好ましい。 Specific raw materials included in the raw material mixture include titanium disulfide TiS 2 , sodium titanate Na 2 Ti 3 O 7 , titanium tetrachloride TiCl 4 , etc. when titanium is included as a transition metal. When containing zirconium as a transition metal, examples include zirconium sulfide ZrS 2 and sodium zirconate Na 2 ZrO 3. When containing hafnium as a transition metal, examples include hafnium sulfide HfS 2 , etc. When containing vanadium as a transition metal. is divanadium trisulfide V 2 S 3 , vanadium tetrasulfide VS 4 , ammonium metavanadate NH 4 VO 3 , sodium orthovanadate Na 3 VO 4 , sodium metavanadate NaVO 3 , divanadium pentoxide V 2 O 5 , tetrachloride Examples include vanadium VCl 4 , montrosite VOOH, etc. When niobium is included as a transition metal, niobium sulfide NbS 2 , sodium niobate NaNbO 3 etc. are included, and when tantalum is included as a transition metal, tantalum sulfide TaS 2 , Examples include sodium tantalate NaTaO 3 , and when chromium is included as a transition metal, chromium sulfide Cr 2 S 3 , sodium chromate Na 2 CrO 4 , sodium dichromate Na 2 Cr 2 O 7 , etc. When molybdenum is included as a metal, examples include molybdenum sulfide MoS 2 , sodium molybdate Na 2 MoO 4 , ammonium molybdate (NH 4 ) 2 MoO 4 , molybdenum trioxide MoO 3 , molybdenum pentachloride MoCl 5 , etc. When tungsten is included as a transition metal, tungsten sulfide WS 2 , sodium tungstate Na 2 WO 4 , ammonium tungstate (NH 4 ) 2 WO 4 , tungsten trioxide WO 3 etc. are included, and when manganese is included as a transition metal, Examples include manganese sulfide MnS, manganese disulfide MnS 2 , sodium manganate Na 2 MnO 4 , and when rhenium is included as a transition metal, rhenium sulfide ReS 2 , ammonium perrhenate NH 4 ReO 4 , sodium metaperrhenate Examples include NaReO4 . These raw material compounds are not particularly limited, and known or commercially available products can be used. In particular, it is preferable to use a highly purified one. Although the form of the raw material compound used is not particularly limited, it is preferable to use a powdered compound since the dispersion is hydrothermally synthesized.
また、硫黄源としては、目的とする組成の硫化物を形成するために必要な量の硫黄源を用いることが可能である。原料として用いる硫黄源についても特に限定はなく、チオアセトアミドCH3CSNH2、チオ尿素SC(NH2)2、チオ硫酸ナトリウムNa2S2O3、硫化アンモニウム(NH4)2S、硫化ナトリウムNa2S、硫黄S等が挙げられる。これらの硫黄源は、特に限定はなく、公知又は市販品を用いることができる。特に、高純度のものを用いることが好ましい。なお、使用する硫黄源の形態も特に制限はないものの、分散液を水熱合成するため、粉末状のものを用いることが好ましい。 Further, as the sulfur source, it is possible to use the amount of sulfur source necessary to form a sulfide having the desired composition. There are no particular limitations on the sulfur sources used as raw materials, and thioacetamide CH 3 CSNH 2 , thiourea SC(NH 2 ) 2 , sodium thiosulfate Na 2 S 2 O 3 , ammonium sulfide (NH 4 ) 2 S, and sodium sulfide Na 2 S, sulfur S, etc. These sulfur sources are not particularly limited, and known or commercially available products can be used. In particular, it is preferable to use a highly purified one. Although the form of the sulfur source used is not particularly limited, it is preferable to use a powdered source since the dispersion is hydrothermally synthesized.
上記した原料混合物の分散液を構成する溶媒としては、上記した原料を分散させることができるものであれば特に制限はないが、例えば、水、アンモニア水、N-メチルピロリドン、ポリビニルピロリドン、N,N-ジメチルホルムアミド、オレイルアミン、オレイン酸、エチレングリコール、オクタデカン、エチレンジアミン等が挙げられる。これらの溶媒は、単独で用いることもでき、2種以上を組合せて用いることもできる。 The solvent constituting the dispersion of the raw material mixture described above is not particularly limited as long as it can disperse the raw materials described above, but examples include water, aqueous ammonia, N-methylpyrrolidone, polyvinylpyrrolidone, N, Examples include N-dimethylformamide, oleylamine, oleic acid, ethylene glycol, octadecane, and ethylenediamine. These solvents can be used alone or in combination of two or more.
上記した原料混合物における各原料の比率については、得られる硫化物の組成が上記した本発明の二次電池用負極活物質が含有する遷移金属硫化物と同様となるように調整することができる。また、分散液中の各原料の濃度については、特に制限はなく、各遷移金属源を0.01～0.1mol/L（特に0.2～0.08mol/L）、硫黄源を0.2～1.5mol/L（特に0.8～1.2mol/L）となるように調整することができる。 The ratio of each raw material in the raw material mixture described above can be adjusted so that the composition of the obtained sulfide is similar to the transition metal sulfide contained in the negative electrode active material for a secondary battery of the present invention described above. There are no particular restrictions on the concentration of each raw material in the dispersion; each transition metal source is 0.01 to 0.1 mol/L (especially 0.2 to 0.08 mol/L), and the sulfur source is 0.2 to 1.5 mol/L (especially 0.2 to 0.08 mol/L). It can be adjusted to 0.8 to 1.2 mol/L).
水熱合成を行う際の温度については、特に制限はなく、上記した本発明の二次電池用負極活物質が含有する遷移金属硫化物が得られやすいため、100～400℃が好ましく、150～300℃がより好ましい。 There is no particular restriction on the temperature during hydrothermal synthesis, and it is preferably 100 to 400°C, and 150 to 300°C is more preferred.
加熱時間については、特に限定はなく、上記した本発明の二次電池用負極活物質が含有する遷移金属硫化物が得られるまで任意の時間加熱することができる。例えば、加熱時間は2～72時間が好ましく、5～48時間がより好ましい。 There is no particular limitation on the heating time, and heating can be performed for any desired period of time until the transition metal sulfide contained in the negative electrode active material for a secondary battery of the present invention described above is obtained. For example, the heating time is preferably 2 to 72 hours, more preferably 5 to 48 hours.
上記した水熱合成により、上記した本発明の二次電池用負極活物質が含有する遷移金属硫化物を微粉末として得ることができる。この際、硫黄イオンと2種類以上の遷移金属イオンとが、2種類以上の金属硫化物を形成するのではなく、1種の遷移金属イオンが他の遷移金属硫化物の構造にドープされ得る。このことは、後述の実施例において、Ｘ線回折分析（XRD）において、1つの金属硫化物に特徴的なピークしか検出してないことからも理解できる。この際、1種の遷移金属イオンの存在によって他の遷移金属硫化物を特定の結晶面に沿って成長させることで結晶性をより高くすることができる。このようなバイメタル層状硫化物は、材料形成中に多くの欠陥と空孔が形成され、層間間隔も拡大するにつれてより多くのナトリウムイオンを収容して容量が向上するとともに、充放電サイクル特性も向上することができる。この後、必要に応じて常法で単離し、次いで水及び有機溶媒（エタノール等）で洗浄し、その後乾燥させることもできる。乾燥条件は適宜設定することができる。 Through the hydrothermal synthesis described above, the transition metal sulfide contained in the negative electrode active material for a secondary battery of the present invention can be obtained as a fine powder. At this time, instead of sulfur ions and two or more types of transition metal ions forming two or more types of metal sulfides, one type of transition metal ion may be doped into the structure of another transition metal sulfide. This can be understood from the fact that only a peak characteristic of one metal sulfide was detected in X-ray diffraction analysis (XRD) in the Examples described below. At this time, the presence of one type of transition metal ion allows another transition metal sulfide to grow along a specific crystal plane, thereby increasing crystallinity. In such a bimetallic layered sulfide, many defects and pores are formed during material formation, and as the interlayer spacing increases, it accommodates more sodium ions, improving capacity and improving charge-discharge cycle characteristics. can do. After this, if necessary, it can be isolated by a conventional method, then washed with water and an organic solvent (ethanol, etc.), and then dried. Drying conditions can be set appropriately.
３．二次電池用負極
本発明の二次電池用負極は、本発明の二次電池用負極活物質を含有する。本発明の二次電池用負極は、例えば、ナトリウムイオン二次電池用負極、リチウムイオン二次電池用負極等のように、各種二次電池に好適に使用することができ、二次電池、特にナトリウムイオン二次電池において、初期充放電容量を十分に高く、充放電サイクル特性を向上させることができる。
3. Negative electrode for secondary batteries The negative electrode for secondary batteries of the present invention contains the negative electrode active material for secondary batteries of the present invention. The negative electrode for secondary batteries of the present invention can be suitably used for various secondary batteries, such as negative electrodes for sodium ion secondary batteries, negative electrodes for lithium ion secondary batteries, etc. In a sodium ion secondary battery, the initial charge/discharge capacity can be sufficiently high and the charge/discharge cycle characteristics can be improved.
この本発明の二次電池用負極は、本発明の二次電池用負極活物質を含有する他は、公知の二次電池用負極と同様の構造とすることができる。例えば、本発明の二次電池用負極活物質と必要に応じて導電助剤及びバインダーを含む負極合剤を銅、アルミニウム、ニッケル、ステンレス、カーボンクロス等の負極集電体に担持させることができる。導電助剤としては、例えば、ハードカーボン（難黒鉛化性炭素）、ソフトカーボン（易黒鉛化性炭素）、グラフェン、還元型酸化グラフェン、カーボンブラック、針状カーボン等の炭素材料を用いることができる。また、バインダーとしては、例えば、ポリフッ化ビニリデン（PVDF）、ポリテトラフルオロエチレン（PTFE）、ポリイミド（PI）、ポリアミド、ポリアミドイミド、ポリアクリル、スチレンブタジエンゴム（SBR）、スチレン－エチレン－ブチレン－スチレン共重合体（SEBS）、カルボキシメチルセルロース（CMC）等の材料を単独で用いることもでき、2種以上を組合せて用いることもできる。 The negative electrode for a secondary battery of the present invention can have the same structure as a known negative electrode for a secondary battery, except that it contains the negative electrode active material for a secondary battery of the present invention. For example, a negative electrode mixture containing the negative electrode active material for secondary batteries of the present invention and, if necessary, a conductive agent and a binder, can be supported on a negative electrode current collector such as copper, aluminum, nickel, stainless steel, or carbon cloth. . As the conductive aid, carbon materials such as hard carbon (non-graphitizable carbon), soft carbon (easily graphitizable carbon), graphene, reduced graphene oxide, carbon black, acicular carbon, etc. can be used, for example. . Examples of binders include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyimide (PI), polyamide, polyamideimide, polyacrylic, styrene-butadiene rubber (SBR), styrene-ethylene-butylene-styrene. Materials such as copolymers (SEBS) and carboxymethyl cellulose (CMC) can be used alone, or two or more types can be used in combination.
本発明の二次電池用負極中の本発明の二次電池用負極活物質の含有量は特に限定されないが、初期充放電容量をより高く、充放電サイクル特性をより向上させることができる観点から、本発明の二次電池用負極の総量を100質量%として、50～95質量%が好ましく、70～90質量%がより好ましい。また、同様の理由により、本発明の二次電池用負極の総量を100質量%として、導電助剤の含有量は2.5～25質量%（特に5～15質量%）が好ましく、バインダーの含有量は2.5～25質量%（特に5～15質量%）が好ましい。 The content of the negative electrode active material for secondary batteries of the present invention in the negative electrode for secondary batteries of the present invention is not particularly limited, but from the viewpoint of higher initial charge/discharge capacity and further improvement of charge/discharge cycle characteristics. , the total amount of the negative electrode for secondary batteries of the present invention is 100% by mass, preferably 50 to 95% by mass, more preferably 70 to 90% by mass. Furthermore, for the same reason, the content of the conductive agent is preferably 2.5 to 25% by mass (especially 5 to 15% by mass), and the content of the binder is 100% by mass, and the content of the binder is 100% by mass. is preferably 2.5 to 25% by mass (especially 5 to 15% by mass).
４．二次電池
本発明の二次電池は本発明の二次電池用負極を備える。つまり、本発明の二次電池は、本発明の二次電池用負極活物質を含有する上記した本発明の二次電池用負極を構成要素として含む。本発明の二次電池は、本発明の二次電池用負極に本発明の二次電池用負極活物質が含まれる限りは、その他の構成は特に限定されず、例えば、公知と同様の構成とすることができる。例えば、本発明の二次電池は、本発明の二次電池用負極活物質が含まれる本発明の二次電池用負極に加えて、正極、電解質及びセパレータを備えることができる。電池の大きさ及び形状は、二次電池の用途に応じて適宜決定することができる。特に、本発明ではナトリウムイオン二次電池における充放電サイクル特性を向上させることができる点において、ナトリウムイオン二次電池として有用である。
4. Secondary battery The secondary battery of the present invention includes the negative electrode for secondary batteries of the present invention. That is, the secondary battery of the present invention includes the above-described negative electrode for a secondary battery of the present invention containing the negative electrode active material for a secondary battery of the present invention as a component. The secondary battery of the present invention is not particularly limited in other configurations as long as the negative electrode for secondary batteries of the present invention contains the negative electrode active material for secondary batteries of the present invention, and for example, the secondary battery may have a configuration similar to a known structure. can do. For example, the secondary battery of the present invention can include a positive electrode, an electrolyte, and a separator in addition to the negative electrode for a secondary battery of the present invention containing the negative electrode active material for a secondary battery of the present invention. The size and shape of the battery can be determined as appropriate depending on the use of the secondary battery. In particular, the present invention is useful as a sodium ion secondary battery in that it can improve the charge/discharge cycle characteristics of the sodium ion secondary battery.
正極は、例えば、金属箔に活物質が担持された構造を有することができる。金属箔としては、アルミニウム、チタン、白金、モリブデン、ステンレス、銅等が挙げられる。金属箔の形状は、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。正極活物質としては、公知の活物質を広く適用することができ、例えば、NaFePO4、Na3V2(PO4)3、NaxMO4（M= Co、Ni、V、Fe; 0≦x≦1）、LiTiS2、LiCoO2、LiNiO2、LiMnO2、LiNi0.33Mn0.33Co0.33O2、LiNi0.8Mn0.15Al0.05O2、LiMn2O4、LiFePO4等を挙げることができる。 The positive electrode can have, for example, a structure in which an active material is supported on a metal foil. Examples of the metal foil include aluminum, titanium, platinum, molybdenum, stainless steel, and copper. Examples of the shape of the metal foil include a porous body, a foil, a plate, a mesh made of fibers, and the like. As the positive electrode active material, a wide range of known active materials can be used, such as NaFePO 4 , Na 3 V 2 (PO 4 ) 3 , Na x MO 4 (M= Co, Ni, V, Fe; 0≦ x≦1), LiTiS 2 , LiCoO 2 , LiNiO 2 , LiMnO 2 , LiNi 0.33 Mn 0.33 Co 0.33 O 2 , LiNi 0.8 Mn 0.15 Al 0.05 O 2 , LiMn 2 O 4 , LiFePO 4 and the like.
電解質としては、固体電解質及び液体電解質のいずれも採用できる。 As the electrolyte, either a solid electrolyte or a liquid electrolyte can be employed.
固体電解質としては、例えば、Li10GeP2S12、xLi2S-(1-x)P2S5（0.6≦x≦0.85）、Na11Sn2PS12等の硫化物電解質；Na3PSe4；Li3xLa2/3-xTiO3（0≦x≦0.16）等の酸化物電解質；Li1+xAlxTi2-x(PO4)3（0≦x≦0.5）（LATP）；LixLa3M2O12（3≦x≦7.5、M= Ta, Nb, Zr）；Na3Zr2Si2PO12；ポリマーベースの電解質等が挙げられる。ポリマーベースの電解質としては、例えば、ポリエチレンオキサイド（PEO）、ポリビニリデンフルオライド（PVDF）等をベースとする電解質が挙げられる。ポリマーベースの電解質は、必要に応じて、LiPF6、LiClO4、リチウムビストリフルオロメチルスルホニルイミド（LiTFSI）、NaClO4、NaBF4等の公知の電解質を含むことができる。その他、固体電解質としては、公知の無機電解質と混合してなるハイブリッド電解質を挙げることもできる。 Examples of solid electrolytes include sulfide electrolytes such as Li 10 GeP 2 S 12 , xLi 2 S-(1-x)P 2 S 5 (0.6≦x≦0.85), Na 11 Sn 2 PS 12 ; Na 3 PSe 4 ; Oxide electrolyte such as Li 3x La 2/3-x TiO 3 (0≦x≦0.16); Li 1+x Al x Ti 2-x (PO 4 ) 3 (0≦x≦0.5) (LATP) ; Li x La 3 M 2 O 12 (3≦x≦7.5, M= Ta, Nb, Zr); Na 3 Zr 2 Si 2 PO 12 ; Polymer-based electrolytes and the like. Polymer-based electrolytes include, for example, electrolytes based on polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), and the like. Polymer-based electrolytes can optionally include known electrolytes such as LiPF 6 , LiClO 4 , lithium bistrifluoromethylsulfonylimide (LiTFSI), NaClO 4 , NaBF 4 and the like. In addition, examples of solid electrolytes include hybrid electrolytes that are mixed with known inorganic electrolytes.
液体電解質としては、極性溶媒に溶解したリチウム塩又はナトリウム塩が挙げられる。極性溶媒としては、例えば、プロピレンカーボネート、エチレンカーボネート（EC）、フルオロエチレンカーボネート、ジメチルカーボネート（DMC）、エチルメチルカーボネート、ジエチルカーボネート（DEC）等のカーボネート化合物；ジエチレングリコールジメチルエーテル（ジグリム）、トリエチレングリコールジメチルエーテル（トリグリム）、1,3-ジオキソラン（DOL）、1,2-ジメトキシエタン（DME）等のエーテル化合物；酢酸プロピル等のエステル化合物等の１種又は２種以上を挙げることができる。リチウム塩としては、例えば、六フッ化リン酸リチウム（LiPF6）、過塩素酸リチウムLiClO4、テトラフルオロホウ酸リチウムLiBF4、リチウムビスオキサレートボラートLiBOB、六フッ化ヒ酸リチウム（LiAsF6）、リチウムビスフルオロスルホニルイミド（LiFSI）、リチウムトリフルオロメタンスルホニルイミド（LiSO3CF3）、リチウムビストリフルオロメタンスルホニルイミド（LiTFSI）等の１種又は２種以上が挙げられる。ナトリウム塩としては、例えば、六フッ化リン酸ナトリウムNaPF6、過塩素酸ナトリウムNaClO4、ナトリウムビスフルオロスルホニルイミド（NaFSI）、ナトリウムトリフルオロメタンスルホニルイミド（NaSO3CF3）、ナトリウムビストリフルオロメタンスルホニルイミド（NaTFSI）等の１種又は２種以上が挙げられる。 Liquid electrolytes include lithium or sodium salts dissolved in polar solvents. Examples of polar solvents include carbonate compounds such as propylene carbonate, ethylene carbonate (EC), fluoroethylene carbonate, dimethyl carbonate (DMC), ethylmethyl carbonate, and diethyl carbonate (DEC); diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), and other ether compounds; and propyl acetate and other ester compounds. Examples of lithium salts include lithium hexafluorophosphate (LiPF 6 ), lithium perchlorate LiClO 4 , lithium tetrafluoroborate LiBF 4 , lithium bisoxalate borate LiBOB, and lithium hexafluoroarsenate (LiAsF 6 ) . ), lithium bisfluorosulfonylimide (LiFSI), lithium trifluoromethanesulfonylimide (LiSO 3 CF 3 ), lithium bistrifluoromethanesulfonylimide (LiTFSI), and the like. Examples of sodium salts include sodium hexafluorophosphate NaPF 6 , sodium perchlorate NaClO 4 , sodium bisfluorosulfonylimide (NaFSI), sodium trifluoromethanesulfonylimide (NaSO 3 CF 3 ), and sodium bistrifluoromethanesulfonylimide. (NaTFSI), etc., or two or more thereof.
セパレータとしては、ナトリウムイオン二次電池、リチウムイオン二次電池等に適用されている公知のセパレータを使用することができ、例えば、ポリエチレン、ポリプロピレン等のポリオレフィン樹脂；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。 As the separator, known separators applied to sodium ion secondary batteries, lithium ion secondary batteries, etc. can be used, such as polyolefin resins such as polyethylene and polypropylene; polyimide; polyvinyl alcohol; It is made of a material such as a fluororesin such as ethylene oxide polytetrafluoroethylene; an acrylic resin; a nylon; an aromatic aramid; an inorganic glass;
二次電池を組み立てる方法も特に制限はなく、公知の二次電池の組み立て方法と同様の方法で二次電池を得ることができる。 The method for assembling the secondary battery is also not particularly limited, and the secondary battery can be obtained by a method similar to a known method for assembling a secondary battery.
以下、実施例により本発明をより具体的に説明するが、本発明はこれら実施例の態様に限定されるものではない。 EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the embodiments of these Examples.
なお、液体電解質であるナトリウムトリフルオロメタンスルホニルイミド（NaSO3CF3）の1Mジグリム溶液はシグマアルドリッチジャパン製を使用し、セパレータはＧＥヘルスケア・ジャパン（株）製のガラス繊維ろ紙グレードGF/F（粒子保持能0.7μm）を使用した。 The liquid electrolyte, 1M diglyme solution of sodium trifluoromethanesulfonylimide (NaSO 3 CF 3 ), was made by Sigma-Aldrich Japan, and the separator was glass fiber filter paper grade GF/F (made by GE Healthcare Japan Co., Ltd.). A particle retention capacity of 0.7 μm) was used.
実施例１：V x Mo 1-x S 2 （V: Mo= 5: 3）
層状複硫化物材料VMoS2-53（VxMo1-xS2; V: Mo元素比5: 3）は、水熱合成法により合成した。
Example 1: V x Mo 1-x S 2 (V: Mo= 5: 3)
The layered double sulfide material VMoS 2 -53 (V x Mo 1-x S 2 ; V:Mo element ratio 5:3) was synthesized by a hydrothermal synthesis method.
2.5mmolのNH4VO3と、1.5mmolのNa2MoO4・H2Oを30mLの蒸留水と2mLの濃アンモニア水の混合液に溶解した（NH4VO3は0.078mol/L、Na2MoO4・H2Oは0.047mol/L）。続いて、37mmolのチオアセトアミドC2H5NSを上記溶液に加え（C2H5NSは1.156mol/L）、超音波処理により溶液中に分散させた。得られた分散液は、テフロン（登録商標）製内筒（容積50mL）を持ったオートクレーブに移し、220℃で24時間加熱した。得られた固体生成物は、遠心分離により回収し、蒸留水とエタノールで繰り返し洗浄した。最後に、真空乾燥機中80℃で12時間乾燥し、実施例１の負極活物質として使用した。 2.5 mmol of NH 4 VO 3 and 1.5 mmol of Na 2 MoO 4 H 2 O were dissolved in a mixture of 30 mL of distilled water and 2 mL of concentrated aqueous ammonia (NH 4 VO 3 was 0.078 mol/L, Na 2 MoO 4 H 2 O is 0.047 mol/L). Subsequently, 37 mmol of thioacetamide C 2 H 5 NS was added to the above solution (C 2 H 5 NS was 1.156 mol/L) and dispersed in the solution by ultrasonication. The obtained dispersion liquid was transferred to an autoclave equipped with a Teflon (registered trademark) inner cylinder (volume: 50 mL) and heated at 220° C. for 24 hours. The resulting solid product was collected by centrifugation and washed repeatedly with distilled water and ethanol. Finally, it was dried in a vacuum dryer at 80°C for 12 hours, and used as the negative electrode active material in Example 1.
実施例２：V x Mo 1-x S 2 （V: Mo= 4: 3）
層状複硫化物材料VMoS2-43（VxMo1-xS2; V: Mo元素比4: 3）は、水熱合成法により合成した。
Example 2: V x Mo 1-x S 2 (V: Mo= 4: 3)
The layered double sulfide material VMoS 2 -43 (V x Mo 1-x S 2 ; V:Mo element ratio 4:3) was synthesized by a hydrothermal synthesis method.
2.0mmolのNH4VO3と、1.5mmolのNa2MoO4・H2Oを30mLの蒸留水と2mLの濃アンモニア水の混合液に溶解した（NH4VO3は0.063mol/L、Na2MoO4・H2Oは0.047mol/L）。続いて、32mmolのチオアセトアミドC2H5NSを上記溶液に加え（C2H5NSは1mol/L）、超音波処理により溶液中に分散させた。得られた分散液は、テフロン製内筒（容積50mL）を持ったオートクレーブに移し、220℃で24時間加熱した。得られた固体生成物は、遠心分離により回収し、蒸留水とエタノールで繰り返し洗浄した。最後に、真空乾燥機中80℃で12時間乾燥し、実施例２の負極活物質として使用した。 2.0 mmol of NH 4 VO 3 and 1.5 mmol of Na 2 MoO 4 H 2 O were dissolved in a mixture of 30 mL of distilled water and 2 mL of concentrated aqueous ammonia (NH 4 VO 3 was 0.063 mol/L, Na 2 MoO 4 H 2 O is 0.047 mol/L). Subsequently, 32 mmol of thioacetamide C 2 H 5 NS was added to the above solution (C 2 H 5 NS was 1 mol/L) and dispersed in the solution by ultrasonication. The resulting dispersion was transferred to an autoclave equipped with a Teflon inner cylinder (volume 50 mL) and heated at 220°C for 24 hours. The resulting solid product was collected by centrifugation and washed repeatedly with distilled water and ethanol. Finally, it was dried in a vacuum dryer at 80°C for 12 hours, and used as the negative electrode active material in Example 2.
比較例１：MoS 2
層状硫化物材料MoS2（Vを含まない）は、水熱合成法により合成した。
Comparative example 1: MoS 2
The layered sulfide material MoS 2 (V-free) was synthesized using a hydrothermal synthesis method.
1.5mmolのNa2MoO4・H2Oを30mLの蒸留水と2mLの濃アンモニア水の混合液に溶解した（Na2MoO4・H2Oは0.047mol/L）。続いて、12mmolのチオアセトアミドC2H5NSを上記溶液に加え（C2H5NSは0.375mol/L）、超音波処理により溶液中に分散させた。得られた分散液は、テフロン製内筒（容積50mL）を持ったオートクレーブに移し、220℃で24時間加熱した。得られた固体生成物は、遠心分離により回収し、蒸留水とエタノールで繰り返し洗浄した。最後に、真空乾燥機中80℃で12時間乾燥し、比較例１の負極活物質として使用した。 1.5 mmol of Na 2 MoO 4 .H 2 O was dissolved in a mixture of 30 mL of distilled water and 2 mL of concentrated aqueous ammonia (Na 2 MoO 4 .H 2 O was 0.047 mol/L). Subsequently, 12 mmol of thioacetamide C 2 H 5 NS was added to the above solution (C 2 H 5 NS was 0.375 mol/L) and dispersed in the solution by ultrasonication. The resulting dispersion was transferred to an autoclave equipped with a Teflon inner cylinder (volume 50 mL) and heated at 220°C for 24 hours. The resulting solid product was collected by centrifugation and washed repeatedly with distilled water and ethanol. Finally, it was dried in a vacuum dryer at 80°C for 12 hours and used as a negative electrode active material in Comparative Example 1.
製造例１：ナトリウムイオン二次電池の製造及び充放電試験
CR2032型の硫化物｜Na金属コイン電池を構築した。このコイン電池において、両極活物質は実施例１～２又は比較例１の負極活物質及びナトリウム金属（正極活物質）とした。負極は、負極集電体として銅箔の上に、負極活物質として実施例１～２又は比較例１の負極活物質80質量%、導電助剤として炭素材料super P10質量%、バインダーとしてカルボキシメチルセルロース（CMC）10質量%からなる負極活物質層を構成した。また、正極は、正極集電体としてアルミニウム箔の上に正極活物質としてナトリウム金属箔を構成した。液体電解質は、シグマアルドリッチジャパンより購入した市販の電解液（ナトリウムトリフルオロメタンスルホニルイミド（NaSO3CF3）の1Mジグリム溶液）を使用した。この液体電解質で湿らせたセパレータ（ガラス繊維ろ紙グレードGF/F）と、前記両極を用い、公知の方法でCR2032型のコイン電池に封入した。得られたナトリウムイオン二次電池は、Wuhan LAND electronics社の充放電装置（LAND batteries testing system CT2001A）を使用して、充放電の電圧範囲を0.3～3.0V、電流密度を1A/gとして30℃で充放電試験を行った。
Production example 1: Production and charge/discharge test of sodium ion secondary battery
A CR2032 type sulfide | Na metal coin battery was constructed. In this coin battery, the negative electrode active materials of Examples 1 to 2 or Comparative Example 1 and sodium metal (positive electrode active material) were used as both electrode active materials. The negative electrode was made of copper foil as a negative electrode current collector, 80% by mass of the negative electrode active material of Examples 1 to 2 or Comparative Example 1 as a negative electrode active material, 10% by mass of carbon material super P as a conductive aid, and carboxymethyl cellulose as a binder. A negative electrode active material layer was composed of 10% by mass (CMC). Further, the positive electrode was composed of a sodium metal foil as a positive electrode active material on an aluminum foil as a positive electrode current collector. As the liquid electrolyte, a commercially available electrolyte (1M diglyme solution of sodium trifluoromethanesulfonylimide (NaSO 3 CF 3 )) purchased from Sigma-Aldrich Japan was used. A separator (glass fiber filter paper grade GF/F) moistened with this liquid electrolyte and the above-mentioned both electrodes were sealed in a CR2032 type coin battery by a known method. The obtained sodium ion secondary battery was charged and discharged at 30°C using a charging/discharging device (LAND batteries testing system CT2001A) from Wuhan LAND electronics with a charging/discharging voltage range of 0.3 to 3.0 V and a current density of 1 A/g. A charge/discharge test was conducted.
なお、電池の構築においては、グローブボックス（（株）美和製作所製）を不活性雰囲気下での電池製作のために使用し、H2O及びO2濃度がいずれも0.1ppm以下であるArガス雰囲気下で行った。また、電池製作に使用したセパレータは直径16mm、厚さ25mmとし、負極活物質（実施例１～２又は比較例１の負極活物質）は、直径12mm、厚さ0.1mmとし、負極集電体（銅箔）は、直径12mm、厚さ0.009mmとし、正極活物質（ナトリウム金属箔）は直径12mm、厚さ0.1mmとし、正極集電体（アルミニウム箔）は直径12mm、厚さ0.016mmとした。 In addition, when constructing the battery, a glove box (manufactured by Miwa Seisakusho Co., Ltd.) was used for battery production under an inert atmosphere, and Ar gas with H 2 O and O 2 concentrations of 0.1 ppm or less was used. I went under the atmosphere. In addition, the separator used for battery production was 16 mm in diameter and 25 mm thick, the negative electrode active material (the negative electrode active material of Examples 1 and 2 or Comparative Example 1) was 12 mm in diameter and 0.1 mm thick, and the negative electrode current collector (copper foil) has a diameter of 12 mm and a thickness of 0.009 mm, the positive electrode active material (sodium metal foil) has a diameter of 12 mm and a thickness of 0.1 mm, and the positive electrode current collector (aluminum foil) has a diameter of 12 mm and a thickness of 0.016 mm. did.
（評価結果）
図１は、実施例１～２及び比較例１で得られた負極活物質の走査型電子顕微鏡像（SEM像）である。走査型電子顕微鏡像（SEM像）では、バナジウムを含む試料、つまり、2種類の遷移金属元素を含む試料（実施例１及び２）においてのみ、針状の結晶が成長していることが理解できる。これは、バナジウムが存在することにより、（００１）面方向の硫化モリブデンのシート状構造への成長を妨げた結果であると推察される。後述の充放電試験の結果とあわせて検討すると、これによって二次電池の性能向上をもたらすものと推測される。
(Evaluation results)
FIG. 1 is a scanning electron microscope image (SEM image) of the negative electrode active materials obtained in Examples 1 to 2 and Comparative Example 1. In the scanning electron microscope image (SEM image), it can be seen that needle-shaped crystals grow only in samples containing vanadium, that is, samples containing two types of transition metal elements (Examples 1 and 2). . This is presumed to be the result of the presence of vanadium inhibiting the growth of molybdenum sulfide into a sheet-like structure in the (001) plane direction. Considering this together with the results of the charge/discharge test described below, it is presumed that this improves the performance of the secondary battery.
図２は、実施例１～２で得られた負極活物質のエネルギー分散型Ｘ線分析（EDX分析）による元素マッピング図である（Aは実施例２、Bは実施例１）。元素マッピング図から、実施例１～２においては、硫黄元素、モリブデン元素及びバナジウム元素が均一に分布していることが理解できる。つまり、硫黄元素、モリブデン元素及びバナジウム元素相互間で結合していることが理解できる。後述の充放電試験の結果とあわせて検討すると、これによって硫黄が低減されており、二次電池の性能向上をもたらすものと推測される。 FIG. 2 is an elemental mapping diagram obtained by energy dispersive X-ray analysis (EDX analysis) of the negative electrode active materials obtained in Examples 1 and 2 (A is Example 2, B is Example 1). From the element mapping diagram, it can be seen that in Examples 1 and 2, sulfur element, molybdenum element, and vanadium element are uniformly distributed. In other words, it can be understood that the sulfur element, the molybdenum element, and the vanadium element are bonded to each other. When considered together with the results of the charge/discharge test described below, it is assumed that this reduces sulfur and improves the performance of the secondary battery.
図３は、実施例１～２及び比較例１で得られた負極活物質のＸ線回折スペクトルである。Ｘ線回折スペクトルでは、バナジウムを含む試料、つまり、2種類の遷移金属元素を含む試料（実施例１及び２）では結晶性が向上し、2θ= 14.8°、32.8°、39.2°及び58.1°の位置において、2H-MoS2の（002）面、（100）面、（103）面及び（110）面に対応するピーク（PCPDS No. 371492）が比較例１と比較して明確且つ鋭く観察された。具体的には、2θ= 14.8°（002面）のピークの半値全幅は0.7°、2θ= 32.8°（100面）のピークの半値全幅は0.9°、2θ= 39.2°（103面）のピークの半値全幅は0.3°、2θ= 58.1°（110面）のピークの半値全幅は0.5°であった。バナジウムが存在することにより、硫化モリブデンが特定の結晶面に沿って成長した結果として結晶性が向上したものと推察される。後述の充放電試験の結果とあわせて検討すると、これによって二次電池の性能向上をもたらすものと推測される。 FIG. 3 shows X-ray diffraction spectra of the negative electrode active materials obtained in Examples 1 and 2 and Comparative Example 1. In the X-ray diffraction spectrum, the crystallinity of the samples containing vanadium, that is, the samples containing two types of transition metal elements (Examples 1 and 2), was improved, and the crystallinity was improved at 2θ = 14.8°, 32.8°, 39.2°, and 58.1°. At these positions, peaks (PCPDS No. 371492) corresponding to the (002) plane, (100) plane, (103) plane, and (110) plane of 2H-MoS 2 were observed clearly and sharply compared to Comparative Example 1. Ta. Specifically, the full width at half maximum of the peak at 2θ = 14.8° (002 plane) is 0.7°, the full width at half maximum of the peak at 2θ = 32.8° (100 plane) is 0.9°, and the full width at half maximum of the peak at 2θ = 39.2° (103 plane) is 0.7°. The full width at half maximum was 0.3°, and the full width at half maximum of the peak at 2θ = 58.1° (110 plane) was 0.5°. It is presumed that the presence of vanadium causes molybdenum sulfide to grow along specific crystal planes, resulting in improved crystallinity. Considering this together with the results of the charge/discharge test described below, it is presumed that this improves the performance of the secondary battery.
図４は、実施例１～２及び比較例１で得られた負極活物質を用いたナトリウムイオン二次電池の電気化学測定（放電容量及び充放電サイクル特性）の結果を示す。充放電サイクル特性は、放電容量の維持率を示している。図４から、1種類の遷移金属元素しか含まない試料（比較例１）では100サイクルの充放電後の放電容量は336mAh/gであったのに対し、2種類の遷移金属元素を含む試料（実施例１及び２）では100サイクルの充放電後の放電容量は482mAh/g（実施例１）及び420mAh/g（実施例２）と優れており、また、既報の値（320mAh/g; 非特許文献２）よりも顕著に優れていた。充放電の進行に伴い、ナトリウムイオンの挿入により、層間間隔が連続的に膨張し、より多くのナトリウムイオンを挿入できるようになり、充放電サイクル特性が向上したものと推察される。 FIG. 4 shows the results of electrochemical measurements (discharge capacity and charge/discharge cycle characteristics) of sodium ion secondary batteries using the negative electrode active materials obtained in Examples 1 to 2 and Comparative Example 1. The charge/discharge cycle characteristics indicate the maintenance rate of discharge capacity. From Figure 4, the discharge capacity of the sample containing only one type of transition metal element (Comparative Example 1) after 100 charge/discharge cycles was 336 mAh/g, whereas the sample containing two types of transition metal elements ( In Examples 1 and 2), the discharge capacity after 100 cycles of charging and discharging was excellent at 482 mAh/g (Example 1) and 420 mAh/g (Example 2), and also exceeded the previously reported value (320 mAh/g; It was significantly superior to Patent Document 2). As charging and discharging proceed, the interlayer spacing expands continuously due to the insertion of sodium ions, making it possible to insert more sodium ions, which is presumably why the charge-discharge cycle characteristics are improved.
Claims (5)
二次元層状構造を有する遷移金属硫化物を含有し、
前記遷移金属硫化物が、一般式（1）：
VxMo1-xS2 （1）
［式中、xは0.1～0.9を示す。］
で表される組成を有する、ナトリウムイオン二次電池用負極活物質。 Containing at least two transition metals belonging to Groups 4 to 7 and 14 of the periodic table and sulfur as constituent elements,
Contains a transition metal sulfide with a two-dimensional layered structure,
The transition metal sulfide has general formula (1):
V x Mo 1-x S 2 (1)
[In the formula, x represents 0.1 to 0.9. ]
A negative electrode active material for a sodium ion secondary battery having a composition represented by:
バナジウム、モリブデン及び硫黄を含む原料混合物の分散液を100～400℃に加熱する工程
を備える、製造方法。 A method for producing a negative electrode active material for a sodium ion secondary battery according to claim 1 or 2 , comprising:
A manufacturing method comprising the step of heating a dispersion of a raw material mixture containing vanadium, molybdenum , and sulfur to 100 to 400°C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019155563A JP7394336B2 (en) | 2019-08-28 | 2019-08-28 | Negative electrode active material for secondary batteries |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019155563A JP7394336B2 (en) | 2019-08-28 | 2019-08-28 | Negative electrode active material for secondary batteries |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2021034290A JP2021034290A (en) | 2021-03-01 |
| JP7394336B2 true JP7394336B2 (en) | 2023-12-08 |
Family
ID=74677578
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2019155563A Active JP7394336B2 (en) | 2019-08-28 | 2019-08-28 | Negative electrode active material for secondary batteries |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP7394336B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116438143A (en) * | 2020-11-10 | 2023-07-14 | 国立研究开发法人产业技术综合研究所 | Vanadium sulfides containing dissimilar elements |
| CN113998739A (en) * | 2021-03-26 | 2022-02-01 | 浙江理工大学 | A kind of preparation method of negative electrode material of sodium ion battery |
| CN115504508A (en) * | 2022-09-21 | 2022-12-23 | 上海大学 | Class V 2-x Cr x S 4 Method for synthesizing lithium-free anode material of lithium ion battery |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000235856A (en) | 1999-02-15 | 2000-08-29 | Sanyo Electric Co Ltd | Lithium secondary battery |
| JP2000243455A (en) | 1998-12-25 | 2000-09-08 | Sanyo Electric Co Ltd | Lithium secondary battery |
| JP2000277115A (en) | 1999-03-25 | 2000-10-06 | Sanyo Electric Co Ltd | Lithium secondary battery |
| JP2001015109A (en) | 1999-06-28 | 2001-01-19 | Sanyo Electric Co Ltd | Lithium secondary battery |
-
2019
- 2019-08-28 JP JP2019155563A patent/JP7394336B2/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000243455A (en) | 1998-12-25 | 2000-09-08 | Sanyo Electric Co Ltd | Lithium secondary battery |
| JP2000235856A (en) | 1999-02-15 | 2000-08-29 | Sanyo Electric Co Ltd | Lithium secondary battery |
| JP2000277115A (en) | 1999-03-25 | 2000-10-06 | Sanyo Electric Co Ltd | Lithium secondary battery |
| JP2001015109A (en) | 1999-06-28 | 2001-01-19 | Sanyo Electric Co Ltd | Lithium secondary battery |
Non-Patent Citations (1)
| Title |
|---|
| Zhang, Ke et al.，Interlayer-expanded VMo2S4 nanosheets on RGO for high and fast lithium and sodium storage，Journal of Alloys and Compounds，2018年09月10日，772，PP.178-185 |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2021034290A (en) | 2021-03-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11271200B2 (en) | Positive-electrode active material containing lithium composite oxide, and battery including the same | |
| US10854876B2 (en) | Positive electrode active material and battery using positive electrode active material | |
| US11605814B2 (en) | Positive-electrode active material containing lithium composite oxide, and battery including the same | |
| US11081687B2 (en) | Positive-electrode active material and battery including positive-electrode active material | |
| US11557760B2 (en) | Positive-electrode active material containing lithium composite oxide, and battery including the same | |
| US10818911B2 (en) | Positive-electrode active material and battery | |
| JP2018116930A (en) | Positive electrode active material and battery | |
| US20200006749A1 (en) | Positive-electrode active material containing lithium composite oxide, and battery including the same | |
| JP7394336B2 (en) | Negative electrode active material for secondary batteries | |
| KR20200121312A (en) | Positive electrode active material, positive electrode, non-aqueous electrolyte storage element, positive electrode active material manufacturing method, positive electrode manufacturing method, and non-aqueous electrolyte storage element manufacturing method | |
| US20170244103A1 (en) | Cathode active material and battery | |
| JP7162274B2 (en) | POSITIVE ACTIVE MATERIAL AND BATTERY INCLUDING SAME | |
| CN107104232B (en) | Positive electrode active material and battery | |
| JP6609217B2 (en) | Composite oxide, positive electrode active material for non-aqueous electrolyte secondary battery, positive electrode for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery, and method for producing composite oxide | |
| CN110880585A (en) | Positive electrode active material and battery provided with the same | |
| KR20160012558A (en) | Composite positive electrode active electrode material for lithium secondary battery and lithium secondary battery comprising positive electrode including the positive electrode active material | |
| JP7142302B2 (en) | POSITIVE ACTIVE MATERIAL AND BATTERY INCLUDING SAME | |
| JP7209163B2 (en) | POSITIVE ACTIVE MATERIAL AND BATTERY INCLUDING SAME | |
| JP7281772B2 (en) | POSITIVE ACTIVE MATERIAL AND BATTERY INCLUDING SAME | |
| JP7142301B2 (en) | POSITIVE ACTIVE MATERIAL AND BATTERY INCLUDING SAME | |
| WO2020049792A1 (en) | Positive electrode active material and battery comprising same | |
| JP7024386B2 (en) | Method for manufacturing negative electrode active material, negative electrode, non-aqueous electrolyte storage element, and non-aqueous electrolyte storage element | |
| CN115249843A (en) | Method for manufacturing secondary battery and secondary battery | |
| CN103872317B (en) | Battery active material and battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20220705 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20230522 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20230530 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20230724 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20230808 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20231004 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20231114 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20231116 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 7394336 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |