WO2023053626A1 - 非水電解質二次電池 - Google Patents
非水電解質二次電池 Download PDFInfo
- Publication number
- WO2023053626A1 WO2023053626A1 PCT/JP2022/025261 JP2022025261W WO2023053626A1 WO 2023053626 A1 WO2023053626 A1 WO 2023053626A1 JP 2022025261 W JP2022025261 W JP 2022025261W WO 2023053626 A1 WO2023053626 A1 WO 2023053626A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- positive electrode
- mixture layer
- electrode mixture
- conductive agent
- aqueous electrolyte
- Prior art date
Links
- 239000011255 nonaqueous electrolyte Substances 0.000 title claims abstract description 23
- 239000000203 mixture Substances 0.000 claims abstract description 90
- 239000006258 conductive agent Substances 0.000 claims abstract description 55
- 239000002245 particle Substances 0.000 claims abstract description 34
- 239000010410 layer Substances 0.000 description 71
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 29
- -1 polytetrafluoroethylene Polymers 0.000 description 18
- 229910002804 graphite Inorganic materials 0.000 description 16
- 239000010439 graphite Substances 0.000 description 16
- 239000002002 slurry Substances 0.000 description 13
- 238000007789 sealing Methods 0.000 description 12
- 239000007774 positive electrode material Substances 0.000 description 11
- 239000011230 binding agent Substances 0.000 description 9
- 239000006230 acetylene black Substances 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 239000002184 metal Substances 0.000 description 8
- 238000012856 packing Methods 0.000 description 8
- 238000005096 rolling process Methods 0.000 description 8
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 239000007773 negative electrode material Substances 0.000 description 6
- 239000002033 PVDF binder Substances 0.000 description 5
- 239000003125 aqueous solvent Substances 0.000 description 5
- 239000008151 electrolyte solution Substances 0.000 description 5
- 229910052744 lithium Inorganic materials 0.000 description 5
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 5
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 4
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 229910021383 artificial graphite Inorganic materials 0.000 description 4
- 229910003002 lithium salt Inorganic materials 0.000 description 4
- 159000000002 lithium salts Chemical group 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 230000035699 permeability Effects 0.000 description 4
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- UZKWTJUDCOPSNM-UHFFFAOYSA-N 1-ethenoxybutane Chemical compound CCCCOC=C UZKWTJUDCOPSNM-UHFFFAOYSA-N 0.000 description 3
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 3
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 3
- 229910015746 LiNi0.88Co0.09Al0.03O2 Inorganic materials 0.000 description 3
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000002131 composite material Substances 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 238000007606 doctor blade method Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 150000002170 ethers Chemical class 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 239000011888 foil Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000012046 mixed solvent Substances 0.000 description 3
- 229910021382 natural graphite Inorganic materials 0.000 description 3
- 229920000573 polyethylene Polymers 0.000 description 3
- 229920005672 polyolefin resin Polymers 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 3
- 229910052723 transition metal Inorganic materials 0.000 description 3
- DHKHKXVYLBGOIT-UHFFFAOYSA-N 1,1-Diethoxyethane Chemical compound CCOC(C)OCC DHKHKXVYLBGOIT-UHFFFAOYSA-N 0.000 description 2
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 description 2
- VQKFNUFAXTZWDK-UHFFFAOYSA-N 2-Methylfuran Chemical compound CC1=CC=CO1 VQKFNUFAXTZWDK-UHFFFAOYSA-N 0.000 description 2
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 description 2
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 2
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- 229920000459 Nitrile rubber Polymers 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- 229920002125 Sokalan® Polymers 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- RDOXTESZEPMUJZ-UHFFFAOYSA-N anisole Chemical compound COC1=CC=CC=C1 RDOXTESZEPMUJZ-UHFFFAOYSA-N 0.000 description 2
- 150000005678 chain carbonates Chemical class 0.000 description 2
- 150000005676 cyclic carbonates Chemical class 0.000 description 2
- MHDVGSVTJDSBDK-UHFFFAOYSA-N dibenzyl ether Chemical compound C=1C=CC=CC=1COCC1=CC=CC=C1 MHDVGSVTJDSBDK-UHFFFAOYSA-N 0.000 description 2
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 2
- USIUVYZYUHIAEV-UHFFFAOYSA-N diphenyl ether Chemical compound C=1C=CC=CC=1OC1=CC=CC=C1 USIUVYZYUHIAEV-UHFFFAOYSA-N 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- FJKIXWOMBXYWOQ-UHFFFAOYSA-N ethenoxyethane Chemical compound CCOC=C FJKIXWOMBXYWOQ-UHFFFAOYSA-N 0.000 description 2
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 2
- FKRCODPIKNYEAC-UHFFFAOYSA-N ethyl propionate Chemical compound CCOC(=O)CC FKRCODPIKNYEAC-UHFFFAOYSA-N 0.000 description 2
- 229910052731 fluorine Inorganic materials 0.000 description 2
- 239000011737 fluorine Substances 0.000 description 2
- 239000006232 furnace black Substances 0.000 description 2
- GAEKPEKOJKCEMS-UHFFFAOYSA-N gamma-valerolactone Chemical compound CC1CCC(=O)O1 GAEKPEKOJKCEMS-UHFFFAOYSA-N 0.000 description 2
- 239000003273 ketjen black Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- AMXOYNBUYSYVKV-UHFFFAOYSA-M lithium bromide Chemical compound [Li+].[Br-] AMXOYNBUYSYVKV-UHFFFAOYSA-M 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002905 metal composite material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000011325 microbead Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229920002239 polyacrylonitrile Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 229920003048 styrene butadiene rubber Polymers 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- ZUHZGEOKBKGPSW-UHFFFAOYSA-N tetraglyme Chemical compound COCCOCCOCCOCCOC ZUHZGEOKBKGPSW-UHFFFAOYSA-N 0.000 description 2
- 229910052718 tin Inorganic materials 0.000 description 2
- ABDKAPXRBAPSQN-UHFFFAOYSA-N veratrole Chemical compound COC1=CC=CC=C1OC ABDKAPXRBAPSQN-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- RBACIKXCRWGCBB-UHFFFAOYSA-N 1,2-Epoxybutane Chemical compound CCC1CO1 RBACIKXCRWGCBB-UHFFFAOYSA-N 0.000 description 1
- ZZXUZKXVROWEIF-UHFFFAOYSA-N 1,2-butylene carbonate Chemical compound CCC1COC(=O)O1 ZZXUZKXVROWEIF-UHFFFAOYSA-N 0.000 description 1
- BGJSXRVXTHVRSN-UHFFFAOYSA-N 1,3,5-trioxane Chemical compound C1OCOCO1 BGJSXRVXTHVRSN-UHFFFAOYSA-N 0.000 description 1
- VDFVNEFVBPFDSB-UHFFFAOYSA-N 1,3-dioxane Chemical compound C1COCOC1 VDFVNEFVBPFDSB-UHFFFAOYSA-N 0.000 description 1
- WNXJIVFYUVYPPR-UHFFFAOYSA-N 1,3-dioxolane Chemical compound C1COCO1 WNXJIVFYUVYPPR-UHFFFAOYSA-N 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- WEEGYLXZBRQIMU-UHFFFAOYSA-N 1,8-cineole Natural products C1CC2CCC1(C)OC2(C)C WEEGYLXZBRQIMU-UHFFFAOYSA-N 0.000 description 1
- GDXHBFHOEYVPED-UHFFFAOYSA-N 1-(2-butoxyethoxy)butane Chemical compound CCCCOCCOCCCC GDXHBFHOEYVPED-UHFFFAOYSA-N 0.000 description 1
- GEWWCWZGHNIUBW-UHFFFAOYSA-N 1-(4-nitrophenyl)propan-2-one Chemical compound CC(=O)CC1=CC=C([N+]([O-])=O)C=C1 GEWWCWZGHNIUBW-UHFFFAOYSA-N 0.000 description 1
- DURPTKYDGMDSBL-UHFFFAOYSA-N 1-butoxybutane Chemical compound CCCCOCCCC DURPTKYDGMDSBL-UHFFFAOYSA-N 0.000 description 1
- RRQYJINTUHWNHW-UHFFFAOYSA-N 1-ethoxy-2-(2-ethoxyethoxy)ethane Chemical compound CCOCCOCCOCC RRQYJINTUHWNHW-UHFFFAOYSA-N 0.000 description 1
- UALKQROXOHJHFG-UHFFFAOYSA-N 1-ethoxy-3-methylbenzene Chemical compound CCOC1=CC=CC(C)=C1 UALKQROXOHJHFG-UHFFFAOYSA-N 0.000 description 1
- BPIUIOXAFBGMNB-UHFFFAOYSA-N 1-hexoxyhexane Chemical compound CCCCCCOCCCCCC BPIUIOXAFBGMNB-UHFFFAOYSA-N 0.000 description 1
- CRWNQZTZTZWPOF-UHFFFAOYSA-N 2-methyl-4-phenylpyridine Chemical compound C1=NC(C)=CC(C=2C=CC=CC=2)=C1 CRWNQZTZTZWPOF-UHFFFAOYSA-N 0.000 description 1
- JWUJQDFVADABEY-UHFFFAOYSA-N 2-methyltetrahydrofuran Chemical compound CC1CCCO1 JWUJQDFVADABEY-UHFFFAOYSA-N 0.000 description 1
- UNDXPKDBFOOQFC-UHFFFAOYSA-N 4-[2-nitro-4-(trifluoromethyl)phenyl]morpholine Chemical compound [O-][N+](=O)C1=CC(C(F)(F)F)=CC=C1N1CCOCC1 UNDXPKDBFOOQFC-UHFFFAOYSA-N 0.000 description 1
- SBUOHGKIOVRDKY-UHFFFAOYSA-N 4-methyl-1,3-dioxolane Chemical compound CC1COCO1 SBUOHGKIOVRDKY-UHFFFAOYSA-N 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- ZAFNJMIOTHYJRJ-UHFFFAOYSA-N Diisopropyl ether Chemical compound CC(C)OC(C)C ZAFNJMIOTHYJRJ-UHFFFAOYSA-N 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- WEEGYLXZBRQIMU-WAAGHKOSSA-N Eucalyptol Chemical compound C1C[C@H]2CC[C@]1(C)OC2(C)C WEEGYLXZBRQIMU-WAAGHKOSSA-N 0.000 description 1
- PSMFFFUWSMZAPB-UHFFFAOYSA-N Eukalyptol Natural products C1CC2CCC1(C)COCC2(C)C PSMFFFUWSMZAPB-UHFFFAOYSA-N 0.000 description 1
- 229910000552 LiCF3SO3 Inorganic materials 0.000 description 1
- 229910013528 LiN(SO2 CF3)2 Inorganic materials 0.000 description 1
- 229910013872 LiPF Inorganic materials 0.000 description 1
- 229910001290 LiPF6 Inorganic materials 0.000 description 1
- 101150058243 Lipf gene Proteins 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical compound CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 description 1
- BEKPOUATRPPTLV-UHFFFAOYSA-N [Li].BCl Chemical compound [Li].BCl BEKPOUATRPPTLV-UHFFFAOYSA-N 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- 150000001642 boronic acid derivatives Chemical class 0.000 description 1
- YFNONBGXNFCTMM-UHFFFAOYSA-N butoxybenzene Chemical compound CCCCOC1=CC=CC=C1 YFNONBGXNFCTMM-UHFFFAOYSA-N 0.000 description 1
- QHIWVLPBUQWDMQ-UHFFFAOYSA-N butyl prop-2-enoate;methyl 2-methylprop-2-enoate;prop-2-enoic acid Chemical compound OC(=O)C=C.COC(=O)C(C)=C.CCCCOC(=O)C=C QHIWVLPBUQWDMQ-UHFFFAOYSA-N 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 150000007942 carboxylates Chemical class 0.000 description 1
- 150000001733 carboxylic acid esters Chemical class 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- RFFOTVCVTJUTAD-UHFFFAOYSA-N cineole Natural products C1CC2(C)CCC1(C(C)C)O2 RFFOTVCVTJUTAD-UHFFFAOYSA-N 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 150000003983 crown ethers Chemical class 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 150000004292 cyclic ethers Chemical class 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 229940019778 diethylene glycol diethyl ether Drugs 0.000 description 1
- SBZXBUIDTXKZTM-UHFFFAOYSA-N diglyme Chemical compound COCCOCCOC SBZXBUIDTXKZTM-UHFFFAOYSA-N 0.000 description 1
- NKDDWNXOKDWJAK-UHFFFAOYSA-N dimethoxymethane Chemical compound COCOC NKDDWNXOKDWJAK-UHFFFAOYSA-N 0.000 description 1
- POLCUAVZOMRGSN-UHFFFAOYSA-N dipropyl ether Chemical compound CCCOCCC POLCUAVZOMRGSN-UHFFFAOYSA-N 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- CYEDOLFRAIXARV-UHFFFAOYSA-N ethyl propyl carbonate Chemical compound CCCOC(=O)OCC CYEDOLFRAIXARV-UHFFFAOYSA-N 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 125000005843 halogen group Chemical group 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000010220 ion permeability Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910001547 lithium hexafluoroantimonate(V) Inorganic materials 0.000 description 1
- 229910001540 lithium hexafluoroarsenate(V) Inorganic materials 0.000 description 1
- HSZCZNFXUDYRKD-UHFFFAOYSA-M lithium iodide Inorganic materials [Li+].[I-] HSZCZNFXUDYRKD-UHFFFAOYSA-M 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- PAZHGORSDKKUPI-UHFFFAOYSA-N lithium metasilicate Chemical compound [Li+].[Li+].[O-][Si]([O-])=O PAZHGORSDKKUPI-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
- 229910052912 lithium silicate Inorganic materials 0.000 description 1
- 229910001537 lithium tetrachloroaluminate Inorganic materials 0.000 description 1
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 description 1
- SWAIALBIBWIKKQ-UHFFFAOYSA-N lithium titanium Chemical compound [Li].[Ti] SWAIALBIBWIKKQ-UHFFFAOYSA-N 0.000 description 1
- HSFDLPWPRRSVSM-UHFFFAOYSA-M lithium;2,2,2-trifluoroacetate Chemical compound [Li+].[O-]C(=O)C(F)(F)F HSFDLPWPRRSVSM-UHFFFAOYSA-M 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- MHAIQPNJLRLFLO-UHFFFAOYSA-N methyl 2-fluoropropanoate Chemical compound COC(=O)C(C)F MHAIQPNJLRLFLO-UHFFFAOYSA-N 0.000 description 1
- RCIJMMSZBQEWKW-UHFFFAOYSA-N methyl propan-2-yl carbonate Chemical compound COC(=O)OC(C)C RCIJMMSZBQEWKW-UHFFFAOYSA-N 0.000 description 1
- KKQAVHGECIBFRQ-UHFFFAOYSA-N methyl propyl carbonate Chemical compound CCCOC(=O)OC KKQAVHGECIBFRQ-UHFFFAOYSA-N 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- HPUOAJPGWQQRNT-UHFFFAOYSA-N pentoxybenzene Chemical compound CCCCCOC1=CC=CC=C1 HPUOAJPGWQQRNT-UHFFFAOYSA-N 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- DLRJIFUOBPOJNS-UHFFFAOYSA-N phenetole Chemical compound CCOC1=CC=CC=C1 DLRJIFUOBPOJNS-UHFFFAOYSA-N 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920000379 polypropylene carbonate Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- YFNKIDBQEZZDLK-UHFFFAOYSA-N triglyme Chemical compound COCCOCCOCCOC YFNKIDBQEZZDLK-UHFFFAOYSA-N 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Images
Classifications
-
- 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
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
-
- 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
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
-
- 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 disclosure relates to non-aqueous electrolyte secondary batteries.
- the positive electrode of a non-aqueous electrolyte secondary battery has a positive electrode current collector made of metal and a positive electrode mixture layer formed on the surface of the positive electrode current collector.
- the positive electrode mixture layer contains, in addition to the positive electrode active material, which is the main component, a conductive agent interposed between the positive electrode active materials to form a conductive path.
- Patent Documents 1 to 3 disclose techniques for changing the content of the conductive agent in the thickness direction of the positive electrode mixture layer.
- acetylene black, carbon black, etc. which have a relatively small average particle size, are used as the conductive agent in order to increase the packing density of the positive electrode mixture layer and improve the battery capacity.
- increasing the thickness of the positive electrode mixture layer has been studied.
- the packing density of the positive electrode mixture layer is increased, the permeability of the electrolytic solution into the positive electrode mixture layer tends to decrease, and the cycle characteristics tend to deteriorate. Become.
- the techniques disclosed in Patent Documents 1 to 3 do not examine the influence of the average particle size of the conductive agent on the cycle characteristics, and there is still room for improvement.
- An object of the present disclosure is to provide a non-aqueous electrolyte secondary battery with high capacity and improved cycle characteristics.
- a non-aqueous electrolyte secondary battery that is one aspect of the present disclosure includes a positive electrode, a negative electrode, a separator that separates the positive electrode and the negative electrode from each other, and a non-aqueous electrolyte. It has a first positive electrode mixture layer formed on the surface of the electric body and a second positive electrode mixture layer formed on the surface of the first positive electrode mixture layer, and the second positive electrode mixture layer has an average particle diameter contains a second conductive agent having a diameter of 0.5 ⁇ m to 15 ⁇ m, and the first positive electrode mixture layer contains the first conductive agent having an average particle size smaller than that of the second conductive agent.
- non-aqueous electrolyte secondary battery According to the non-aqueous electrolyte secondary battery according to the present disclosure, it is possible to improve battery capacity and cycle characteristics.
- FIG. 1 is an axial cross-sectional view of a non-aqueous electrolyte secondary battery that is an example of an embodiment
- FIG. 1 is a cross-sectional view of a positive electrode that is an example of an embodiment
- FIG. 1 is a cross-sectional view of a positive electrode that is an example of an embodiment
- a cylindrical battery in which a wound electrode body is housed in a cylindrical outer body is exemplified, but the outer body is not limited to a cylindrical shape, and may be, for example, rectangular, coin-shaped, etc. It may be of a pouch type composed of a laminate sheet including a metal layer and a resin layer. Further, the electrode body may be a laminated electrode body in which a plurality of positive electrodes and a plurality of negative electrodes are alternately laminated with separators interposed therebetween. Further, in this specification, the description of "numerical value (A) to numerical value (B)" means numerical value (A) or more and numerical value (B) or less.
- FIG. 1 is an axial cross-sectional view of a cylindrical secondary battery 10 that is an example of an embodiment.
- an electrode body 14 and a non-aqueous electrolyte (not shown) are housed in an exterior body 15 .
- the electrode body 14 has a wound structure in which the positive electrode 11 and the negative electrode 12 are wound with the separator 13 interposed therebetween.
- the sealing member 16 side will be referred to as "upper”
- the bottom side of the outer package 15 will be referred to as "lower”.
- the inside of the secondary battery 10 is hermetically sealed by closing the upper open end of the exterior body 15 with the sealing body 16 .
- Insulating plates 17 and 18 are provided above and below the electrode body 14, respectively.
- the positive electrode lead 19 extends upward through the through hole of the insulating plate 17 and is welded to the lower surface of the filter 22 which is the bottom plate of the sealing member 16 .
- the cap 26, which is the top plate of the sealing member 16 electrically connected to the filter 22, serves as a positive electrode terminal.
- the negative electrode lead 20 extends through the outside of the insulating plate 18 to the bottom side of the exterior body 15 and is welded to the bottom inner surface of the exterior body 15 .
- the exterior body 15 becomes a negative electrode terminal.
- the exterior body 15 is, for example, a bottomed cylindrical metal exterior can.
- a gasket 27 is provided between the exterior body 15 and the sealing body 16 to ensure hermetic sealing of the inside of the secondary battery 10 .
- the exterior body 15 has, for example, a grooved portion 21 formed by pressing the side portion from the outside.
- the grooved portion 21 is preferably annularly formed along the circumferential direction of the exterior body 15 and supports the sealing body 16 via a gasket 27 on its upper surface.
- the sealing body 16 has a filter 22, a lower valve body 23, an insulating member 24, an upper valve body 25, and a cap 26 which are stacked in order from the electrode body 14 side.
- Each member constituting the sealing member 16 has, for example, a disk shape or a ring shape, and each member other than the insulating member 24 is electrically connected to each other.
- the lower valve body 23 and the upper valve body 25 are connected to each other at their central portions, and an insulating member 24 is interposed between their peripheral edge portions.
- the positive electrode 11, the negative electrode 12, the separator 13, and the non-aqueous electrolyte that constitute the secondary battery 10 will be described in detail below, particularly the positive electrode 11.
- FIG. 2 is a cross-sectional view of the positive electrode 11 that is an example of the embodiment.
- the positive electrode 11 includes a positive electrode current collector 30, a first positive electrode mixture layer 32 formed on the surface of the positive electrode current collector 30, and a second positive electrode mixture layer formed on the surface of the first positive electrode mixture layer 32. 34.
- the first positive electrode mixture layer 32 and the second positive electrode mixture layer 34 may be collectively referred to as a positive electrode mixture layer 36 .
- the positive electrode current collector 30 a foil of a metal such as aluminum that is stable in the potential range of the positive electrode, a film having the metal on the surface layer, or the like can be used.
- the thickness of the positive electrode current collector 30 is, for example, 10 ⁇ m to 30 ⁇ m.
- the positive electrode mixture layers 36 are preferably formed on both sides of the positive electrode current collector 30 .
- the thickness of the positive electrode mixture layer 36 on one side of the positive electrode current collector 30 is preferably 50 ⁇ m to 200 ⁇ m, more preferably 70 ⁇ m to 150 ⁇ m.
- the positive electrode mixture layer 36 contains, for example, a positive electrode active material, a conductive agent, and a binder.
- positive electrode active materials include lithium-containing composite oxides containing transition metal elements such as Co, Mn, and Ni.
- a positive electrode active material may be used individually by 1 type, and may be used in mixture of multiple types.
- the positive electrode active material contained in the first positive electrode mixture layer 32 and the positive electrode active material contained in the second positive electrode mixture layer 34 may be different from each other, but are preferably the same.
- binder contained in the positive electrode mixture layer 36 examples include fluorine-based resins such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polyimide-based resins, acrylic-based resins, polyolefin-based resins and the like. These may be used individually by 1 type, and may be used in combination of 2 or more types.
- the binder contained in the first positive electrode mixture layer 32 and the binder contained in the second positive electrode mixture layer 34 may be different from each other, but are preferably the same.
- Examples of the conductive agent contained in the positive electrode mixture layer 36 include carbon-based particles such as acetylene black, furnace black, ketjen black, and graphite. These may be used alone or in combination of two or more.
- the conductive agent contained in the positive electrode mixture layer 36 is different between the first positive electrode mixture layer 32 and the second positive electrode mixture layer 34 . That is, the first positive electrode mixture layer 32 contains the first conductive agent, and the second positive electrode mixture layer 34 contains the second conductive agent.
- the first positive electrode mixture layer 32 may contain a conductive agent other than the first conductive agent, and the second positive electrode mixture layer 34 may contain a conductive agent other than the second conductive agent, as long as the object of the present disclosure is not impaired. agent.
- the average particle size of the second conductive agent is 0.5 ⁇ m to 15 ⁇ m, preferably 1 ⁇ m to 10 ⁇ m, more preferably 3 ⁇ m to 9 ⁇ m. This improves the permeability of the electrolytic solution and improves the cycle characteristics. In particular, in high-rate charge/discharge, the improvement in cycle characteristics is remarkable.
- the average particle size means a volume-based median size (D50). D50 means a particle size at which the cumulative frequency is 50% from the smaller particle size in the volume-based particle size distribution, and is also called median diameter.
- the particle size distributions of the first conductive agent and the second conductive agent can be measured using a laser diffraction particle size distribution analyzer (eg MT3000II manufactured by Microtrack Bell Co., Ltd.) using water as a dispersion medium.
- the average particle size of the first conductive agent is smaller than that of the second conductive agent. Thereby, the battery capacity can be improved.
- the average particle size of the second conductive agent is preferably 1 nm to 500 nm, more preferably 5 nm to 100 nm, particularly preferably 10 nm to 50 nm.
- the ratio of the average particle size of the first conductive agent to the average particle size of the second conductive agent is preferably 50 to 300, more preferably. is 100-200.
- the second conductive agent may be graphite.
- Graphite used as the second conductive agent may be any of natural graphite such as flake graphite, massive graphite, earthy graphite, etc., artificial graphite such as massive artificial graphite, and graphitized mesophase carbon microbeads, and is natural graphite. is preferred.
- the first conductive agent may be one or more of acetylene black, furnace black, or ketjen black, preferably acetylene black.
- the thickness ratio between the first positive electrode mixture layer 32 and the second positive electrode mixture layer 34 is preferably 90:10 to 10:90, more preferably 75:25 to 25:75. This makes it possible to achieve both high capacity and improved cycle characteristics.
- the battery capacity can be increased by increasing the thickness of the first positive electrode mixture layer 32 .
- Cycle characteristics can be improved by increasing the thickness of the second positive electrode mixture layer 34 .
- the content of the first conductive agent is preferably 0.1 to 5 parts by mass, more preferably is 0.5 parts by mass to 3 parts by mass.
- the content of the second conductive agent is preferably 0.1 to 5 parts by mass, More preferably, it is 0.5 parts by mass to 3 parts by mass.
- the content of the first conductive agent in the first positive electrode mixture layer 32 and the content of the second conductive agent in the second positive electrode mixture layer 34 may differ from each other, but are preferably the same.
- the method for producing the positive electrode 11 is not particularly limited, but for example, a first positive electrode mixture slurry containing a positive electrode active material, a first conductive agent, and a binder, a positive electrode active material, a second conductive agent, and a binder
- the first positive electrode mixture slurry was applied to both surfaces of the positive electrode current collector 30 and dried, and the second positive electrode mixture slurry was applied and dried thereon. After that, by rolling the coating film with a rolling roller, the positive electrode 11 having a positive electrode mixture layer having a two-layer structure as shown in FIG. 2 can be manufactured. Further, after applying the first positive electrode mixture slurry, the second positive electrode mixture slurry may be applied thereon without drying, and then dried.
- the negative electrode 12 has a negative electrode current collector and a negative electrode mixture layer formed on the surface of the negative electrode current collector.
- a foil of a metal such as copper that is stable in the potential range of the negative electrode, a film having the metal on the surface layer, or the like can be used.
- the thickness of the negative electrode current collector is, for example, 5 ⁇ m to 30 ⁇ m.
- the negative electrode mixture layers are preferably formed on both sides of the negative electrode current collector.
- the thickness of the negative electrode mixture layer is, for example, 10 ⁇ m to 150 ⁇ m on one side of the negative electrode current collector.
- the negative electrode mixture layer contains, for example, a negative electrode active material and a binder.
- the negative electrode is produced, for example, by applying a negative electrode mixture slurry containing a negative electrode active material, a binder, etc. on both sides of a negative electrode current collector, drying the coating film, and then rolling the coating film using a roller or the like. can be made.
- the negative electrode active material contained in the negative electrode mixture layer is not particularly limited as long as it can reversibly absorb and release lithium ions, and carbon materials such as graphite are generally used.
- Graphite may be any of natural graphite such as flaky graphite, massive graphite and earthy graphite, artificial graphite such as massive artificial graphite and graphitized mesophase carbon microbeads.
- a metal alloyed with Li such as Si or Sn, a metal compound containing Si, Sn or the like, a lithium-titanium composite oxide, or the like may be used.
- Si-containing compound represented by SiO x (0.5 ⁇ x ⁇ 1.6) or a lithium silicate phase represented by Li 2y SiO (2+y) (0 ⁇ y ⁇ 2) contains fine particles of Si.
- a dispersed Si-containing compound or the like may be used in combination with graphite.
- binder contained in the negative electrode mixture layer examples include styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), carboxymethylcellulose (CMC) or salts thereof, polyacrylic acid (PAA) or salts thereof (PAA -Na, PAA-K, and partially neutralized salts), polyvinyl alcohol (PVA), and the like. These may be used individually by 1 type, and may be used in combination of 2 or more types.
- the separator 13 separates the positive electrode 11 and the negative electrode 12 from each other.
- a porous sheet or the like having ion permeability and insulation is used as the separator 13.
- porous sheets include microporous membranes, woven fabrics, and non-woven fabrics.
- Suitable materials for the separator include olefin resins such as polyethylene and polypropylene, and cellulose.
- the separator 13 may be a laminate having a cellulose fiber layer and a thermoplastic resin fiber layer such as an olefin resin.
- a multilayer separator including a polyethylene layer and a polypropylene layer may be used, and a separator 13 having a surface coated with a material such as aramid resin or ceramic may be used.
- a non-aqueous electrolyte is, for example, an electrolytic solution containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.
- non-aqueous solvents examples include esters, ethers, nitriles such as acetonitrile, amides such as dimethylformamide, and mixed solvents of two or more thereof.
- the non-aqueous solvent may contain a halogen-substituted product obtained by substituting at least part of the hydrogen atoms of these solvents with halogen atoms such as fluorine.
- halogen-substituted compounds include fluorinated cyclic carbonates such as fluoroethylene carbonate (FEC), fluorinated chain carbonates, and fluorinated chain carboxylates such as methyl fluoropropionate (FMP).
- FEC fluoroethylene carbonate
- FMP fluorinated chain carboxylates
- esters examples include cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC) and butylene carbonate, dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), methyl propyl carbonate. , Ethyl propyl carbonate, Methyl isopropyl carbonate, and other chain carbonates; ⁇ -Butyrolactone (GBL), ⁇ -Valerolactone (GVL), and other cyclic carboxylic acid esters; ), chain carboxylic acid esters such as ethyl propionate, and the like.
- cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC) and butylene carbonate, dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), methyl propyl carbonate.
- Ethyl propyl carbonate Methyl isopropyl carbonate
- ethers examples include 1,3-dioxolane, 4-methyl-1,3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, propylene oxide, 1,2-butylene oxide, 1,3-dioxane, 1,4 -dioxane, 1,3,5-trioxane, furan, 2-methylfuran, 1,8-cineol, cyclic ethers such as crown ether, 1,2-dimethoxyethane, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether , dihexyl ether, ethyl vinyl ether, butyl vinyl ether, methyl phenyl ether, ethyl phenyl ether, butyl phenyl ether, pentyl phenyl ether, methoxytoluene, benzyl ethyl ether, diphenyl ether, cycl
- the electrolyte salt is a lithium salt.
- lithium salts include LiBF4 , LiClO4 , LiPF6 , LiAsF6 , LiSbF6 , LiAlCl4 , LiSCN, LiCF3SO3 , LiCF3CO2 , Li(P( C2O4 ) F4 ) , LiPF 6-x (C n F 2n+1 ) x (1 ⁇ x ⁇ 6, n is 1 or 2), LiB 10 Cl 10 , LiCl, LiBr, LiI, lithium chloroborane, lithium lower aliphatic carboxylate, Li 2 B 4O7 , borates such as Li (B( C2O4 ) F2 ), LiN( SO2CF3 ) 2 , LiN( C1F2l + 1SO2 )( CmF2m + 1SO2 ) ⁇ l , where m is an integer equal to or greater than 0 ⁇ .
- Lithium salts may be used singly or in combination. Of these, it is preferable to use LiPF 6 from the viewpoint of ion conductivity, electrochemical stability, and the like.
- the lithium salt concentration may be, for example, 0.8 mol to 1.8 mol per 1 L of the non-aqueous solvent.
- Example> [Preparation of positive electrode] Acetylene black (AB) having an average particle size of 35 nm was used as the first conductive agent. LiNi 0.88 Co 0.09 Al 0.03 O 2 Lithium transition metal composite oxide represented by LiNi 0.88 Co 0.09 Al 0.03 O 2, the first conductive agent, and polyvinylidene fluoride (PVDF) were mixed at a weight ratio of 100: 1: 0.9 They were mixed at the same ratio and kneaded while adding N-methylpyrrolidone (NMP) to prepare a first positive electrode mixture slurry.
- NMP N-methylpyrrolidone
- the first positive electrode mixture slurry is applied to both sides of a positive electrode current collector made of aluminum foil having a thickness of 15 ⁇ m by a doctor blade method, and the coating film is dried to form a first positive electrode mixture layer (uncompressed state). bottom.
- Graphite with an average particle size of 6 ⁇ m was used as the second conductive agent.
- a lithium transition metal composite oxide represented by LiNi 0.88 Co 0.09 Al 0.03 O 2 , a second conductive agent, and PVDF are mixed at a mass ratio of 100:1:0.9, The mixture was kneaded while adding N-methylpyrrolidone (NMP) to prepare a second positive electrode mixture slurry.
- NMP N-methylpyrrolidone
- the second positive electrode mixture slurry is applied to both surfaces of the first positive electrode mixture layer by a doctor blade method, and the coating film is dried, thereby covering the entire surface of the first positive electrode mixture layer with the second positive electrode mixture slurry.
- the layers were laminated.
- the first positive electrode mixture layer and the second positive electrode mixture layer After rolling the first positive electrode mixture layer and the second positive electrode mixture layer using rollers, they were cut into a predetermined electrode size to prepare a positive electrode. In addition, an exposed portion where the positive electrode current collector was exposed was provided on a part of the positive electrode, and an aluminum positive electrode lead was attached to the exposed portion. After rolling, the packing density of the positive electrode was 3.6 g/cm 3 .
- the thickness of the positive electrode mixture layer was 100 ⁇ m on one side of the positive electrode current collector.
- the ratio of the thickness of the first positive electrode mixture layer to the thickness of the second positive electrode mixture layer was 50:50.
- Negative electrode active material carboxymethyl cellulose (CMC): styrene-butadiene rubber (SBR) were kneaded in water so that the mass ratio was 100:1:1 to prepare a negative electrode mixture slurry.
- CMC carboxymethyl cellulose
- SBR styrene-butadiene rubber
- the negative electrode mixture slurry is applied to both sides of a negative electrode current collector made of copper foil by a doctor blade method, and after drying, the coating film is rolled with a roller and cut into a predetermined electrode size to form a negative electrode. was made.
- an exposed portion where the surface of the negative electrode current collector was exposed was provided on a part of the negative electrode, and a negative electrode lead made of nickel was attached to the exposed portion.
- Lithium hexafluorophosphate LiPF 6 was added at a concentration of 1.5 mol/L to a mixed solvent in which ethylene carbonate (EC) and dimethyl carbonate (DMC) were mixed at a volume ratio of 1:3. Dissolved. Furthermore, vinylene carbonate (VC) was dissolved in the mixed solvent at a concentration of 5% by mass to prepare a non-aqueous electrolyte (electrolytic solution).
- a wound electrode body was produced by spirally winding the positive electrode and the negative electrode through a separator made of a polyethylene film having a thickness of 12 ⁇ m. This electrode body was housed in a bottomed cylindrical outer package, and the negative electrode lead was welded to the bottom of the outer package. Next, the positive electrode lead was welded to the sealing body, and after the non-aqueous electrolyte was injected, the opening of the exterior body was sealed with the sealing body to obtain a secondary battery.
- a secondary battery was produced in the same manner as in Examples, except that graphite with an average particle size of 6 ⁇ m was used as the first conductive agent and AB with an average particle size of 35 nm was used as the second conductive agent in the production of the positive electrode. and evaluated. After rolling, the packing density of the positive electrode was 3.6 g/cm 3 .
- ⁇ Comparative Example 2> A secondary battery was fabricated and evaluated in the same manner as in Examples, except that graphite having an average particle size of 6 ⁇ m was used as the first conductive agent in fabricating the positive electrode. After rolling, the packing density of the positive electrode was 3.4 g/cm 3 . Since the average particle size of the first conductive agent in Comparative Example 2 is larger than the average particle size of the first conductive agent in Examples, even if the positive electrode mixture layer is rolled at the same linear pressure, the packing density is lower than that in Examples. is presumed to have decreased.
- Table 1 shows the evaluation results of the secondary batteries of Examples and Comparative Examples. Table 1 also shows the average particle size of the first conductive agent and the second conductive agent, and the packing density of the positive electrode.
- the secondary batteries of the examples excellent battery capacity and capacity retention rate are obtained.
- the secondary batteries of Comparative Examples 1 and 3 in which the second positive electrode mixture layer contains a conductive agent having a small average particle size, are inferior in capacity retention rate to the secondary batteries of Examples.
- the secondary batteries of Comparative Examples 1 and 3 have a longer liquid absorption time than the secondary batteries of Examples.
- the secondary battery of Comparative Example 2 in which the first positive electrode mixture layer contains a conductive agent having a large average particle size, is inferior in battery capacity to the secondary batteries of Examples.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Secondary Cells (AREA)
Abstract
Description
図2を参照しつつ正極11の構成について説明する。図2は、実施形態の一例である正極11の断面図である。正極11は、正極集電体30と、正極集電体30の表面に形成された第1正極合剤層32と、第1正極合剤層32の表面に形成された第2正極合剤層34とを有する。なお、第1正極合剤層32及び第2正極合剤層34をまとめて正極合剤層36という場合がある。
負極12は、負極集電体と、負極集電体の表面に形成された負極合剤層とを有する。負極集電体には、銅などの負極の電位範囲で安定な金属の箔、当該金属を表層に配置したフィルム等を用いることができる。負極集電体の厚みは、例えば、5μm~30μmである。
セパレータ13は、正極11及び負極12を相互に隔離する。セパレータ13としては、例えば、イオン透過性及び絶縁性を有する多孔性シート等が用いられる。多孔性シートの具体例としては、微多孔膜、織布、不織布等が挙げられる。セパレータの材質としては、ポリエチレン、ポリプロピレン等のオレフィン系樹脂、セルロースなどが好適である。セパレータ13は、セルロース繊維層及びオレフィン系樹脂等の熱可塑性樹脂繊維層を有する積層体であってもよい。また、ポリエチレン層及びポリプロピレン層を含む多層セパレータであってもよく、セパレータ13の表面にアラミド系樹脂、セラミック等の材料が塗布されたものを用いてもよい。
非水電解質は、例えば、非水溶媒と、非水溶媒に溶解した電解質塩とを含む電解液である。非水溶媒としては、例えばエステル類、エーテル類、アセトニトリル等のニトリル類、ジメチルホルムアミド等のアミド類、及びこれらの2種以上の混合溶媒等を用いることができる。非水溶媒は、これら溶媒の水素の少なくとも一部をフッ素等のハロゲン原子で置換したハロゲン置換体を含有していてもよい。ハロゲン置換体としては、フルオロエチレンカーボネート(FEC)等のフッ素化環状炭酸エステル、フッ素化鎖状炭酸エステル、フルオロプロピオン酸メチル(FMP)等のフッ素化鎖状カルボン酸エステル等が挙げられる。
[正極の作製]
第1導電剤として、平均粒子径35nmのアセチレンブラック(AB)を用いた。LiNi0.88Co0.09Al0.03O2で表されるリチウム遷移金属複合酸化物と、第1導電剤と、ポリフッ化ビニリデン(PVDF)とを、100:1:0.9の質量比で混合し、N-メチルピロリドン(NMP)を加えながら混錬して、第1正極合剤スラリーを調製した。次に、第1正極合剤スラリーを厚み15μmのアルミニウム箔からなる正極集電体の両面にドクターブレード法により塗布し、塗膜を乾燥させて第1正極合剤層(未圧縮状態)を形成した。
黒鉛が95質量部、SiOが5質量部となるように混合し、これを負極活物質とした。負極活物質:カルボキシメチルセルロース(CMC):スチレンブタジエンゴム(SBR)の質量比が、100:1:1となるようにこれらを水中で混練して、負極合剤スラリーを調製した。次に、銅箔からなる負極集電体の両面に、ドクターブレード法により、負極合剤スラリーを塗布、乾燥させた後、ローラにより塗膜を圧延し、所定の電極サイズに切断して、負極を作製した。また、負極の一部に負極集電体の表面が露出した露出部を設け、当該露出部にニッケル製の負極リードを取り付けた。
エチレンカーボネート(EC)と、ジメチルカーボネート(DMC)とを、1:3の体積比で混合した混合溶媒に対して、六フッ化リン酸リチウム(LiPF6)を1.5モル/Lの濃度で溶解させた。さらに、ビニレンカーボネート(VC)を上記混合溶媒に対して5質量%の濃度で溶解させて、非水電解質(電解液)を調製した。
厚み12μmのポリエチレンフィルムからなるセパレータを介して正極と負極を渦巻き状に巻回して巻回型電極体を作製した。この電極体を有底円筒形状の外装体内に収容し、負極リードを当該外装体の底部に溶接した。次に、正極リードを封口体に溶接し、上記非水電解質を注入した後、外装体の開口部を封口体で封止して、二次電池を得た。
環境温度25℃の下、上記の二次電池を、3680mAで4.2Vまで定電流充電した後、4.2Vで92mAまで定電圧充電した。その後、2300mAで、2.5Vまで定電流放電した。この充放電を1サイクルとして、200サイクル行い、下記式により容量維持率を求めた。また、1サイクル目の放電容量を電池容量とした。
容量維持率=(200サイクル目の放電容量/1サイクル目の放電容量)×100
正極を、窒素雰囲気下200℃に加温した恒温槽で10時間乾燥させた後に、2cm×5cmの大きさにカットして試料を作製した。試料の表面に、3μLのポリプロピレンカーボネート(PC)を垂直方向から滴下し、PCが試料の内部に吸収されるまでの時間を目視により測定した。この測定を6回行い、平均値を吸液時間とした。なお、吸液時間が短いほど、電解液の浸透性が良いことを示している。
正極の作製において、第1導電剤として、平均粒子径6μmの黒鉛を用い、第2導電剤として、平均粒子径35nmのABを用いたこと以外は、実施例と同様にして二次電池を作製し、評価を行った。圧延後において、正極の充填密度は、3.6g/cm3であった。
正極の作製において、第1導電剤として、平均粒子径6μmの黒鉛を用いたこと以外は、実施例と同様にして二次電池を作製し、評価を行った。圧延後において、正極の充填密度は、3.4g/cm3であった。比較例2における第1導電剤の平均粒子径が実施例における第1導電剤の平均粒子径よりも大きいため、同じ線圧で正極合剤層を圧延しても、実施例に比べて充填密度が低くなったと推察される。
正極の作製において、第2導電剤として、平均粒子径35nmのABを用いたこと以外は、実施例と同様にして二次電池を作製し、評価を行った。圧延後において、正極の充填密度は、3.6g/cm3であった。
Claims (2)
- 正極と、負極と、前記正極及び前記負極を相互に隔離するセパレータと、非水電解質とを備える非水電解質二次電池であって、
前記正極は、正極集電体と、前記正極集電体の表面に形成された第1正極合剤層と、前記第1正極合剤層の表面に形成された第2正極合剤層とを有し、
前記第2正極合剤層は、平均粒子径が0.5μm~15μmの第2導電剤を含み、
前記第1正極合剤層は、平均粒子径が前記第2導電剤の平均粒子径よりも小さい第1導電剤を含む、非水電解質二次電池。 - 前記第1正極合剤層と前記第2正極合剤層との厚みの比は、90:10~10:90である、請求項1に記載の非水電解質二次電池。
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202280063234.3A CN117957665A (zh) | 2021-09-28 | 2022-06-24 | 非水电解质二次电池 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2021157788 | 2021-09-28 | ||
JP2021-157788 | 2021-09-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2023053626A1 true WO2023053626A1 (ja) | 2023-04-06 |
Family
ID=85780588
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2022/025261 WO2023053626A1 (ja) | 2021-09-28 | 2022-06-24 | 非水電解質二次電池 |
Country Status (2)
Country | Link |
---|---|
CN (1) | CN117957665A (ja) |
WO (1) | WO2023053626A1 (ja) |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009004181A (ja) * | 2007-06-20 | 2009-01-08 | Nissan Motor Co Ltd | 電池用電極 |
JP2010262916A (ja) | 2009-05-08 | 2010-11-18 | Samsung Sdi Co Ltd | リチウム2次電池用電極及びその製造方法と前記電極を含むリチウム2次電池 |
JP2011009203A (ja) * | 2009-05-26 | 2011-01-13 | Nissan Motor Co Ltd | 電極構造、電池および電極構造の製造方法 |
JP2012243463A (ja) * | 2011-05-17 | 2012-12-10 | Hitachi Vehicle Energy Ltd | 非水電解質二次電池 |
JP2018500714A (ja) | 2015-03-17 | 2018-01-11 | エルジー・ケム・リミテッド | 多層構造の電極及びそれを含むリチウム二次電池 |
JP2019515465A (ja) * | 2016-11-23 | 2019-06-06 | エルジー・ケム・リミテッド | 二次電池用正極及びこれを含むリチウム二次電池 |
WO2021106860A1 (ja) * | 2019-11-27 | 2021-06-03 | ビークルエナジージャパン株式会社 | 二次電池用電極、それを備えた二次電池、および二次電池用電極の製造方法 |
-
2022
- 2022-06-24 CN CN202280063234.3A patent/CN117957665A/zh active Pending
- 2022-06-24 WO PCT/JP2022/025261 patent/WO2023053626A1/ja active Application Filing
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009004181A (ja) * | 2007-06-20 | 2009-01-08 | Nissan Motor Co Ltd | 電池用電極 |
JP2010262916A (ja) | 2009-05-08 | 2010-11-18 | Samsung Sdi Co Ltd | リチウム2次電池用電極及びその製造方法と前記電極を含むリチウム2次電池 |
JP2011009203A (ja) * | 2009-05-26 | 2011-01-13 | Nissan Motor Co Ltd | 電極構造、電池および電極構造の製造方法 |
JP2012243463A (ja) * | 2011-05-17 | 2012-12-10 | Hitachi Vehicle Energy Ltd | 非水電解質二次電池 |
JP2018500714A (ja) | 2015-03-17 | 2018-01-11 | エルジー・ケム・リミテッド | 多層構造の電極及びそれを含むリチウム二次電池 |
JP2019515465A (ja) * | 2016-11-23 | 2019-06-06 | エルジー・ケム・リミテッド | 二次電池用正極及びこれを含むリチウム二次電池 |
WO2021106860A1 (ja) * | 2019-11-27 | 2021-06-03 | ビークルエナジージャパン株式会社 | 二次電池用電極、それを備えた二次電池、および二次電池用電極の製造方法 |
Also Published As
Publication number | Publication date |
---|---|
CN117957665A (zh) | 2024-04-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP7319265B2 (ja) | 非水電解質二次電池 | |
JP7182107B2 (ja) | 非水電解質二次電池用正極活物質、非水電解質二次電池用正極活物質の製造方法、及び非水電解質二次電池 | |
WO2017150055A1 (ja) | 非水電解質二次電池 | |
JP7270155B2 (ja) | 非水電解質二次電池 | |
US20220399575A1 (en) | Non-aqueous electrolyte secondary battery | |
JP7361340B2 (ja) | 非水電解質二次電池用負極及び非水電解質二次電池 | |
WO2023053625A1 (ja) | 非水電解質二次電池 | |
JP7233013B2 (ja) | 非水電解質二次電池 | |
JP2021099939A (ja) | 非水電解質二次電池用負極及び非水電解質二次電池 | |
JP7300658B2 (ja) | 非水電解質二次電池用正極活物質、及び非水電解質二次電池 | |
WO2021065162A1 (ja) | 非水電解質二次電池用正極活物質、及び非水電解質二次電池 | |
JP7361339B2 (ja) | 非水電解質二次電池用負極及び非水電解質二次電池 | |
JP7233010B2 (ja) | 二次電池用正極、二次電池用正極集電体、及び二次電池 | |
WO2023053626A1 (ja) | 非水電解質二次電池 | |
WO2022230654A1 (ja) | 非水電解質二次電池 | |
WO2022158375A1 (ja) | 非水電解質二次電池 | |
WO2023013286A1 (ja) | 非水電解質二次電池 | |
WO2023127425A1 (ja) | 非水電解質二次電池用正極活物質及び非水電解質二次電池 | |
WO2023276660A1 (ja) | 非水電解質二次電池 | |
WO2023234099A1 (ja) | 非水電解質二次電池 | |
WO2022202361A1 (ja) | 非水電解質二次電池用正極、非水電解質二次電池用正極の製造方法、及び非水電解質二次電池 | |
WO2023210584A1 (ja) | 非水電解質二次電池 | |
WO2022230658A1 (ja) | 非水電解質二次電池、及び非水電解質二次電池の製造方法 | |
WO2023162698A1 (ja) | 非水電解質二次電池用正極活物質、及び非水電解質二次電池 | |
WO2023145506A1 (ja) | 非水電解質二次電池 |
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: 22875505 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2023550374 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 202280063234.3 Country of ref document: CN |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2022875505 Country of ref document: EP Effective date: 20240429 |