CN116918094A - Positive electrode slurry composition and lithium secondary battery manufactured using same - Google Patents
Positive electrode slurry composition and lithium secondary battery manufactured using same Download PDFInfo
- Publication number
- CN116918094A CN116918094A CN202280015253.9A CN202280015253A CN116918094A CN 116918094 A CN116918094 A CN 116918094A CN 202280015253 A CN202280015253 A CN 202280015253A CN 116918094 A CN116918094 A CN 116918094A
- Authority
- CN
- China
- Prior art keywords
- positive electrode
- slurry composition
- electrode slurry
- secondary battery
- conductive material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000203 mixture Substances 0.000 title claims abstract description 99
- 239000011267 electrode slurry Substances 0.000 title claims abstract description 93
- 229910052744 lithium Inorganic materials 0.000 title claims description 69
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims description 68
- 239000004020 conductor Substances 0.000 claims abstract description 78
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 claims abstract description 53
- 239000002270 dispersing agent Substances 0.000 claims abstract description 49
- 239000007774 positive electrode material Substances 0.000 claims abstract description 45
- 239000011230 binding agent Substances 0.000 claims abstract description 19
- 239000002904 solvent Substances 0.000 claims abstract description 17
- 239000007787 solid Substances 0.000 claims description 21
- 230000002776 aggregation Effects 0.000 claims description 17
- 238000005054 agglomeration Methods 0.000 claims description 16
- 239000000126 substance Substances 0.000 claims description 11
- 229910052782 aluminium Inorganic materials 0.000 claims description 8
- 150000001875 compounds Chemical class 0.000 claims description 6
- 229920000459 Nitrile rubber Polymers 0.000 claims description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 230000004323 axial length Effects 0.000 claims description 3
- 229910052757 nitrogen Inorganic materials 0.000 claims description 3
- 229910052717 sulfur Inorganic materials 0.000 claims description 3
- 229910052731 fluorine Inorganic materials 0.000 claims description 2
- 229910052720 vanadium Inorganic materials 0.000 claims description 2
- 229910052727 yttrium Inorganic materials 0.000 claims description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 37
- 239000002245 particle Substances 0.000 description 23
- 230000000052 comparative effect Effects 0.000 description 18
- 229910052799 carbon Inorganic materials 0.000 description 16
- -1 polytetrafluoroethylene Polymers 0.000 description 16
- 238000004519 manufacturing process Methods 0.000 description 14
- 239000011248 coating agent Substances 0.000 description 13
- 238000000576 coating method Methods 0.000 description 13
- 239000003792 electrolyte Substances 0.000 description 13
- 229920001577 copolymer Polymers 0.000 description 12
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 11
- 238000001878 scanning electron micrograph Methods 0.000 description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 7
- 239000006183 anode active material Substances 0.000 description 7
- 150000001993 dienes Chemical class 0.000 description 7
- 238000001035 drying Methods 0.000 description 7
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 6
- 239000002033 PVDF binder Substances 0.000 description 6
- 239000002041 carbon nanotube Substances 0.000 description 6
- 229910021393 carbon nanotube Inorganic materials 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 238000009831 deintercalation Methods 0.000 description 6
- 239000010408 film Substances 0.000 description 6
- 238000009830 intercalation Methods 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 239000003960 organic solvent Substances 0.000 description 6
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 5
- 239000005977 Ethylene Substances 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- 239000010949 copper Substances 0.000 description 5
- 230000002687 intercalation Effects 0.000 description 5
- 239000000178 monomer Substances 0.000 description 5
- 229910052759 nickel Inorganic materials 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 4
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 4
- 239000003575 carbonaceous material Substances 0.000 description 4
- 239000000835 fiber Substances 0.000 description 4
- 229910003002 lithium salt Inorganic materials 0.000 description 4
- 159000000002 lithium salts Chemical class 0.000 description 4
- 239000004745 nonwoven fabric Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 4
- 239000010935 stainless steel Substances 0.000 description 4
- 229910052719 titanium Inorganic materials 0.000 description 4
- 239000010936 titanium Substances 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 229920000049 Carbon (fiber) Polymers 0.000 description 3
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 3
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- RRHGJUQNOFWUDK-UHFFFAOYSA-N Isoprene Chemical compound CC(=C)C=C RRHGJUQNOFWUDK-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 3
- 229920002472 Starch Polymers 0.000 description 3
- 239000006230 acetylene black Substances 0.000 description 3
- 239000011884 anode binding agent Substances 0.000 description 3
- 229910021383 artificial graphite Inorganic materials 0.000 description 3
- 239000004917 carbon fiber Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 3
- XPFVYQJUAUNWIW-UHFFFAOYSA-N furfuryl alcohol Chemical compound OCC1=CC=CO1 XPFVYQJUAUNWIW-UHFFFAOYSA-N 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 239000003273 ketjen black Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910021382 natural graphite Inorganic materials 0.000 description 3
- 239000007773 negative electrode material Substances 0.000 description 3
- 150000002825 nitriles Chemical class 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 229910052709 silver Inorganic materials 0.000 description 3
- 239000004332 silver Substances 0.000 description 3
- 239000008107 starch Substances 0.000 description 3
- 235000019698 starch Nutrition 0.000 description 3
- 229920003048 styrene butadiene rubber Polymers 0.000 description 3
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 description 2
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 description 2
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- 229920002943 EPDM rubber Polymers 0.000 description 2
- 229920002153 Hydroxypropyl cellulose Polymers 0.000 description 2
- 101150058243 Lipf gene Proteins 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 229920000265 Polyparaphenylene Polymers 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 2
- KAESVJOAVNADME-UHFFFAOYSA-N Pyrrole Chemical compound C=1C=CNC=1 KAESVJOAVNADME-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 239000006231 channel black Substances 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- NJLLQSBAHIKGKF-UHFFFAOYSA-N dipotassium dioxido(oxo)titanium Chemical compound [K+].[K+].[O-][Ti]([O-])=O NJLLQSBAHIKGKF-UHFFFAOYSA-N 0.000 description 2
- 238000004146 energy storage Methods 0.000 description 2
- LYCAIKOWRPUZTN-UHFFFAOYSA-N ethylene glycol Natural products OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 229920001973 fluoroelastomer Polymers 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 239000006232 furnace black Substances 0.000 description 2
- 239000001863 hydroxypropyl cellulose Substances 0.000 description 2
- 235000010977 hydroxypropyl cellulose Nutrition 0.000 description 2
- 239000006233 lamp black Substances 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- 229910021437 lithium-transition metal oxide Inorganic materials 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 229920001542 oligosaccharide Polymers 0.000 description 2
- 150000002482 oligosaccharides Chemical class 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 229920006254 polymer film Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 2
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 2
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000004627 regenerated cellulose Substances 0.000 description 2
- 229920005608 sulfonated EPDM Polymers 0.000 description 2
- 239000006234 thermal black Substances 0.000 description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 2
- 239000011787 zinc oxide Substances 0.000 description 2
- DURPTKYDGMDSBL-UHFFFAOYSA-N 1-butoxybutane Chemical compound CCCCOCCCC DURPTKYDGMDSBL-UHFFFAOYSA-N 0.000 description 1
- XNWFRZJHXBZDAG-UHFFFAOYSA-N 2-METHOXYETHANOL Chemical compound COCCO XNWFRZJHXBZDAG-UHFFFAOYSA-N 0.000 description 1
- IZXIZTKNFFYFOF-UHFFFAOYSA-N 2-Oxazolidone Chemical compound O=C1NCCO1 IZXIZTKNFFYFOF-UHFFFAOYSA-N 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- GUBGYTABKSRVRQ-XLOQQCSPSA-N Alpha-Lactose Chemical compound O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@H]1O[C@@H]1[C@@H](CO)O[C@H](O)[C@H](O)[C@H]1O GUBGYTABKSRVRQ-XLOQQCSPSA-N 0.000 description 1
- 238000004438 BET method Methods 0.000 description 1
- 229910000925 Cd alloy Inorganic materials 0.000 description 1
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 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
- 229930091371 Fructose Natural products 0.000 description 1
- 239000005715 Fructose Substances 0.000 description 1
- RFSUNEUAIZKAJO-ARQDHWQXSA-N Fructose Chemical compound OC[C@H]1O[C@](O)(CO)[C@@H](O)[C@@H]1O RFSUNEUAIZKAJO-ARQDHWQXSA-N 0.000 description 1
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 1
- GUBGYTABKSRVRQ-QKKXKWKRSA-N Lactose Natural products OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O GUBGYTABKSRVRQ-QKKXKWKRSA-N 0.000 description 1
- 229910010238 LiAlCl 4 Inorganic materials 0.000 description 1
- 229910010090 LiAlO 4 Inorganic materials 0.000 description 1
- 229910015015 LiAsF 6 Inorganic materials 0.000 description 1
- 229910013063 LiBF 4 Inorganic materials 0.000 description 1
- 229910013372 LiC 4 Inorganic materials 0.000 description 1
- 229910013684 LiClO 4 Inorganic materials 0.000 description 1
- 229910010710 LiFePO Inorganic materials 0.000 description 1
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 1
- 229910013872 LiPF Inorganic materials 0.000 description 1
- 229910012513 LiSbF 6 Inorganic materials 0.000 description 1
- 229910000572 Lithium Nickel Cobalt Manganese Oxide (NCM) Inorganic materials 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- GYCMBHHDWRMZGG-UHFFFAOYSA-N Methylacrylonitrile Chemical compound CC(=C)C#N GYCMBHHDWRMZGG-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 1
- 229910000676 Si alloy Inorganic materials 0.000 description 1
- 229910001128 Sn alloy Inorganic materials 0.000 description 1
- 239000002174 Styrene-butadiene Substances 0.000 description 1
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 description 1
- 229930006000 Sucrose Natural products 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 description 1
- SOXUFMZTHZXOGC-UHFFFAOYSA-N [Li].[Mn].[Co].[Ni] Chemical compound [Li].[Mn].[Co].[Ni] SOXUFMZTHZXOGC-UHFFFAOYSA-N 0.000 description 1
- FBDMTTNVIIVBKI-UHFFFAOYSA-N [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] Chemical compound [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] FBDMTTNVIIVBKI-UHFFFAOYSA-N 0.000 description 1
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 229910003481 amorphous carbon Inorganic materials 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 239000010426 asphalt Substances 0.000 description 1
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 description 1
- 229920001400 block copolymer Polymers 0.000 description 1
- IAQRGUVFOMOMEM-UHFFFAOYSA-N butene Natural products CC=CC IAQRGUVFOMOMEM-UHFFFAOYSA-N 0.000 description 1
- 239000003660 carbonate based solvent Substances 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000006182 cathode active material Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 239000012461 cellulose resin Substances 0.000 description 1
- 239000011294 coal tar pitch Substances 0.000 description 1
- CKFRRHLHAJZIIN-UHFFFAOYSA-N cobalt lithium Chemical compound [Li].[Co] CKFRRHLHAJZIIN-UHFFFAOYSA-N 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 229920001940 conductive polymer Polymers 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 150000005676 cyclic carbonates Chemical class 0.000 description 1
- 150000004292 cyclic ethers Chemical class 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 238000010294 electrolyte impregnation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 239000004210 ether based solvent Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 239000008103 glucose Substances 0.000 description 1
- 239000011357 graphitized carbon fiber Substances 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- GNOIPBMMFNIUFM-UHFFFAOYSA-N hexamethylphosphoric triamide Chemical compound CN(C)P(=O)(N(C)C)N(C)C GNOIPBMMFNIUFM-UHFFFAOYSA-N 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000005453 ketone based solvent Substances 0.000 description 1
- 239000008101 lactose Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000007561 laser diffraction method Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- ACFSQHQYDZIPRL-UHFFFAOYSA-N lithium;bis(1,1,2,2,2-pentafluoroethylsulfonyl)azanide Chemical compound [Li+].FC(F)(F)C(F)(F)S(=O)(=O)[N-]S(=O)(=O)C(F)(F)C(F)(F)F ACFSQHQYDZIPRL-UHFFFAOYSA-N 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 231100000053 low toxicity Toxicity 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 239000011302 mesophase pitch Substances 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- PYLWMHQQBFSUBP-UHFFFAOYSA-N monofluorobenzene Chemical compound FC1=CC=CC=C1 PYLWMHQQBFSUBP-UHFFFAOYSA-N 0.000 description 1
- 150000005181 nitrobenzenes Chemical class 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 239000011301 petroleum pitch Substances 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 229920001384 propylene homopolymer Polymers 0.000 description 1
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 1
- 239000002296 pyrolytic carbon Substances 0.000 description 1
- 239000001008 quinone-imine dye Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000005720 sucrose Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 239000011269 tar Substances 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- BDZBKCUKTQZUTL-UHFFFAOYSA-N triethyl phosphite Chemical compound CCOP(OCC)OCC BDZBKCUKTQZUTL-UHFFFAOYSA-N 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- PAPBSGBWRJIAAV-UHFFFAOYSA-N ε-Caprolactone Chemical compound O=C1CCCCCO1 PAPBSGBWRJIAAV-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The present application relates to a positive electrode slurry composition comprising a positive electrode active material, a dispersant, a conductive material, a binder, and a solvent, wherein the positive electrode active material comprises lithium iron phosphate, and the dispersant has a weight average molecular weight of 10,000g/mol to 150,000g/mol.
Description
Technical Field
The present application claims priority from korean patent application No. 10-2021-0187722, filed 24 at 12 months of 2021, and korean patent application No. 10-2022-0179775, filed 20 at 12 months of 2022, the disclosures of which are incorporated herein by reference.
The present application relates to a positive electrode slurry composition and a lithium secondary battery manufactured using the same, and more particularly, to a positive electrode slurry composition including a low molecular weight dispersant and a lithium secondary battery manufactured using the same.
Background
As the technology development and demand for electric vehicles and Energy Storage Systems (ESS) increase, the demand for batteries as energy sources increases rapidly, and thus, various researches on batteries capable of satisfying various demands have been conducted. In particular, lithium secondary batteries, which exhibit excellent life and cycle characteristics while having high energy density, are being actively studied as power sources for devices.
As a positive electrode active material of a lithium secondary battery, lithium cobalt-based oxides, lithium nickel cobalt manganese-based oxides, lithium iron phosphate, and the like have been used.
Among those listed above, lithium iron phosphate is inexpensive because it is abundant in resources and contains low cost material iron. Also, since lithium iron phosphate has low toxicity, environmental pollution can be reduced when lithium iron phosphate is used. In addition, since the lithium iron phosphate has an olivine structure, the active material structure can be stably maintained at high temperature as compared with the lithium transition metal oxide having a layered structure. Therefore, the high temperature stability and the high temperature life characteristics of the battery may be excellent.
However, lithium iron phosphate has problems of poor lithium mobility and low electrical conductivity compared to lithium transition metal oxides such as lithium nickel cobalt manganese oxide. Therefore, in general, lithium iron phosphate having a small average particle size is used to shorten the moving path of lithium, the surface of the lithium iron phosphate is coated with carbon to improve the electrical conductivity, and an excessive amount of conductive material is used.
However, as the particle size of the lithium iron phosphate decreases, the specific surface area of the lithium iron phosphate increases, and the lithium iron phosphate coated with carbon on the surface exhibits reduced wettability with respect to the solvent. As a result, serious particle agglomeration of lithium iron phosphate occurs, whereby stability and coating workability of the positive electrode slurry are reduced. In addition, when an excessive amount of conductive material is used, agglomeration between conductive material particles excessively occurs in the positive electrode slurry. As the amount of the agglomerated conductive material increases, the amount of lithium iron phosphate capable of participating in the charge/discharge reaction of the battery relatively decreases, and as a result, the charge/discharge resistance of the lithium secondary battery may increase.
Accordingly, there is a need for a technique to inhibit agglomeration of particles in positive electrode slurry compositions and positive electrodes that include lithium iron phosphate.
Disclosure of Invention
Technical problem
The present application aims to provide a positive electrode slurry composition having a relatively low viscosity and a relatively high solid content by improving dispersibility of a positive electrode active material and/or a conductive material in the positive electrode slurry composition and suppressing particle agglomeration.
The present application is also directed to providing a lithium secondary battery having a reduced discharge resistance by improving dispersibility of a positive electrode active material and/or a conductive material in a positive electrode and suppressing particle agglomeration.
Technical proposal
According to an embodiment of the present application, there is provided a positive electrode slurry composition including a positive electrode active material, a dispersant, a conductive material, a binder, and a solvent, wherein the positive electrode active material includes lithium iron phosphate, and the dispersant has a weight average molecular weight of 10,000g/mol to 150,000g/mol.
According to another embodiment of the present application, there is provided a lithium secondary battery including a positive electrode, wherein the positive electrode includes a positive electrode active material, a dispersant, a conductive material, and a binder, the positive electrode active material includes lithium iron phosphate, and the dispersant has a weight average molecular weight of 10,000g/mol to 150,000g/mol.
Advantageous effects
Since the positive electrode slurry composition according to the present application contains the dispersing agent having a low weight average molecular weight, the solvent wettability and dispersibility of lithium iron phosphate particles contained in the positive electrode slurry composition are improved, whereby particle agglomeration of lithium iron phosphate can be suppressed. Thus, the positive electrode slurry composition may have a low viscosity and also have a high solids content as compared to other positive electrode slurry compositions having the same viscosity.
In addition, since particle agglomeration of lithium iron phosphate can be suppressed, stability and coating workability of the positive electrode slurry composition can be improved.
In addition, since the positive electrode slurry composition according to the present application has a relatively high solid content, the time required for the slurry drying process in the manufacture of the positive electrode is shortened, whereby the process cost can be reduced.
Further, since the dispersant has a low weight average molecular weight, the conductive material is agglomerated in a spherical form in the positive electrode, whereby the surface area of the agglomerated conductive material can be minimized as compared with the conductive material agglomerated in a linear form. As a result, the surface area of the positive electrode active material that is positioned adjacent to the agglomerated conductive material and thus does not participate in the lithium intercalation/deintercalation reaction is minimized, whereby the discharge resistance of the lithium secondary battery manufactured using the positive electrode slurry composition can be reduced.
Drawings
Fig. 1 is a Scanning Electron Microscope (SEM) image of a cross section of a positive electrode in the lithium secondary battery of example 1.
Fig. 2 is an SEM image of a cross section of the positive electrode in the lithium secondary battery of example 2.
Fig. 3 is an SEM image of a cross section of the positive electrode in the lithium secondary battery of example 3.
Fig. 4 is an SEM image of the cross section of the positive electrode in the lithium secondary battery of comparative example 1.
Detailed Description
The advantages and features of the present application and methods for practicing the present application will be apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings. However, the present application is not limited to the exemplary embodiments described below, and may be implemented in various forms. Rather, the exemplary embodiments have been provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art to which the application pertains, and the application will only be defined by the scope of the appended claims. Like reference numerals refer to like elements throughout the specification.
Unless defined otherwise, all terms used herein, including technical or scientific terms, should be interpreted to have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Thus, terms such as those defined in commonly used dictionaries should not be interpreted in an idealized or overly formal sense unless expressly so defined.
The terminology used herein is for the purpose of describing example embodiments and is not intended to be limiting of the application. In this specification, the singular forms may include the plural unless specifically stated in the phrase. As used herein, the terms "comprising" and/or "including" do not exclude the presence or addition of more than one other component in addition to the components mentioned.
In this specification, when a component is referred to as "comprising," "including," "comprising," or "having" another component, it should be understood that the component does not exclude other components, but may also include other components, unless expressly stated otherwise.
In the present specification, reference to "a and/or B" means A, B or a and B.
In the present specification, "%" means weight% unless explicitly described otherwise.
In the present specification, D 50 Refers to a particle size corresponding to 50% of the cumulative volume in the particle size distribution curve. D (D) 50 May be measured, for example, by laser diffraction. Laser diffraction methods are generally capable of measuring particle diameters in the range of submicron to several millimeters, and can obtain results with high reproducibility and high resolution.
In the present specification, the "specific surface area" is measured by the BET method, and can be specifically calculated from the amount of adsorbed nitrogen gas at the liquid nitrogen temperature (77K) using the BELSORP-mini II available from BEL japan corporation.
In the present specification, after cooling the positive electrode slurry composition at room temperature and 1% relative humidity for one hour, a viscometer (Brookfield Co.) was used at 25℃and 10 -2 The viscosity of the positive electrode slurry composition was measured at a shear rate of rpm. The viscosity measurement was performed within 2 hours, including the cooling time after the positive electrode slurry composition was prepared.
In the present specification, the SOC50 discharge resistance refers to a value obtained by dividing a voltage drop value displayed when a discharge pulse is applied for 10 seconds in a state of charge (SOC) of 50% and at 2.5C by a current value.
Hereinafter, embodiments of the present application will be described in detail.
Positive electrode slurry composition
The positive electrode slurry composition according to an embodiment of the present application is intended to form a positive electrode active material layer and includes a positive electrode active material, a dispersant, a conductive material, a binder, and a solvent, wherein the positive electrode active material includes lithium iron phosphate, and the dispersant has a weight average molecular weight of 10,000g/mol to 150,000g/mol.
In the case of a conventional positive electrode slurry composition including lithium iron phosphate, particle agglomeration of lithium iron phosphate excessively occurs due to small particle size of lithium iron phosphate and carbon coating formed on the surface of lithium iron phosphate, whereby stability and coating workability of the positive electrode slurry are reduced. In addition, when an excessive amount of conductive material is used to improve the conductivity of the positive electrode, excessive agglomeration occurs between the conductive material particles, whereby the conductive network of the positive electrode is deteriorated. As a result, the charge/discharge resistance of the lithium secondary battery increases.
As a result of long-term studies to solve the above problems, the inventors of the present application found that when a low-weight average molecular weight dispersant is contained in a positive electrode slurry composition, the dispersibility of a positive electrode active material and/or a conductive material in the positive electrode slurry composition can be improved, and particle agglomeration can be suppressed. This will be described in detail below.
(1) Positive electrode active material
The positive electrode active material may include lithium iron phosphate. When the positive electrode active material includes lithium iron phosphate, the stability of the positive electrode including the positive electrode active material is significantly improved, and thus the ignition of the lithium secondary battery including the positive electrode may be significantly reduced.
The lithium iron phosphate may be a compound represented by the following chemical formula 1.
[ chemical formula 1]
Li 1+a Fe 1-x M x (PO 4-b )X b
(in the chemical formula 1,
m comprises any one or more elements selected from Al, mg, ni, co, mn, ti, ga, cu, V, nb, zr, ce, in, zn, Y,
x contains any one or more elements selected from F, S and N, and a, b and X respectively satisfy-0.5.ltoreq.a.ltoreq.0.5, 0.ltoreq.b.ltoreq.0.1 and 0.ltoreq.x.ltoreq.0.5
For example, the lithium iron phosphate may be LiFePO 4 。
The lithium iron phosphate may include a carbon coating on a surface thereof. When the carbon coating is formed on the surface of the lithium iron phosphate, the electrical conductivity is enhanced, whereby the resistance characteristics of the positive electrode can be improved.
The carbon coating may be formed using at least one raw material selected from the group consisting of: glucose, sucrose, lactose, starch, oligosaccharides, poly-oligosaccharides, fructose, cellulose, furfuryl alcohol polymers, block copolymers of ethylene and ethylene oxide, vinyl resins, cellulose resins, phenolic resins, bitumen resins and tar resins. Specifically, the carbon coating may be formed by mixing raw materials with lithium iron phosphate and heat-treating the resulting mixture.
Average particle diameter D of lithium iron phosphate 50 May be 0.8 μm to 20.0 μm, specifically 0.9 μm to 10.0 μm, more specifically 0.9 μm to 3.0 μm. Average particle diameter D of the cathode active material 50 When the above range is satisfied, lithium mobility in the lithium iron phosphate is improved, so that charge/discharge characteristics of the battery can be improved.
The BET specific surface area of the lithium iron phosphate may be 5m 2 /g to 20m 2 /g, in particular 7m 2 /g to 18m 2 /g, more particularly 9m 2 /g to 16m 2 And/g. The above range is a low BET specific surface area range compared to conventional lithium iron phosphate. When the above range is satisfied, agglomeration of lithium iron phosphate can be effectively suppressed even in a positive electrode slurry composition having a relatively small amount of dispersant.
The content of lithium iron phosphate may be 93 to 98 wt%, specifically 93.5 to 98 wt%, more specifically 94 to 97 wt%, based on the total solids content of the positive electrode slurry composition. When the content of lithium iron phosphate satisfies the above range, a sufficient energy density of the positive electrode is ensured, whereby the battery capacity of the positive electrode can be improved.
(2) Dispersing agent
The dispersant suppresses excessive agglomeration of lithium iron phosphate in the positive electrode slurry composition and allows lithium iron phosphate to be effectively dispersed in the prepared positive electrode active material layer.
The dispersant may comprise a hydrogenated nitrile copolymer. In particular, the dispersant may be a hydrogenated nitrile copolymer.
Specifically, the hydrogenated nitrile copolymer may be a copolymer comprising structural units derived from an α, β -unsaturated nitrile and structural units derived from a hydrogenated conjugated diene, or a copolymer comprising structural units derived from an α, β -unsaturated nitrile, structural units derived from a conjugated diene, and structural units derived from a hydrogenated conjugated diene. As the α, β -unsaturated nitrile monomer, for example, acrylonitrile, methacrylonitrile, and the like can be used, and they may be used alone or in combination of two or more thereof. As the conjugated diene monomer, for example, C4 to C6 conjugated diene monomers such as 1, 3-butadiene, isoprene, 2, 3-methylbutadiene, and the like may be used, and they may be used alone or in combination of two or more thereof.
More specifically, the hydrogenated nitrile copolymer may be hydrogenated nitrile butadiene rubber (H-NBR).
The dispersant may have a weight average molecular weight of from 10,000g/mol to 150,000g/mol, preferably from 15,000g/mol to 140,000g/mol, more preferably from 20,000g/mol to 130,000g/mol. This value is lower than the weight average molecular weight of the dispersant contained in the conventional positive electrode slurry composition.
When the weight average molecular weight of the dispersant is less than 10,000g/mol, the dispersibility of lithium iron phosphate is reduced, and the dispersant may be eluted in the preparation of an electrode. When the weight average molecular weight of the dispersant exceeds 150,000g/mol, the positive electrode slurry composition has a high viscosity, whereby the stability and coating processability of the positive electrode slurry composition may be lowered and the conductive material may be agglomerated in a linear form. Therefore, it is not preferable in terms of the resistance of the lithium secondary battery.
On the other hand, when the weight average molecular weight of the dispersant satisfies the above range, the solvent wettability and dispersibility of the lithium iron phosphate particles are improved, so that particle agglomeration of the lithium iron phosphate can be suppressed. Thus, the positive electrode slurry composition may have a low viscosity and also have a high solids content as compared to other positive electrode slurry compositions having the same viscosity.
Further, when the weight average molecular weight of the dispersant satisfies the above range, the conductive material is agglomerated in a spherical form in the positive electrode, whereby the surface area of the agglomerated conductive material can be minimized as compared with the conductive material agglomerated in a linear form. As a result, the surface area of the positive electrode active material that is positioned adjacent to the agglomerated conductive material and thus does not participate in the lithium intercalation/deintercalation reaction is minimized, whereby the discharge resistance of the lithium secondary battery manufactured using the positive electrode slurry composition can be reduced.
The content of the dispersant may be 0.2 to 1.0 wt%, specifically 0.2 to 0.9 wt%, more specifically 0.3 to 0.8 wt%, based on the total solids content of the positive electrode slurry composition. When the content of the dispersant satisfies the above range, aggregation of the conductive material in the positive electrode active material layer is suppressed, so that the conductive network of the positive electrode can be improved.
(3) Adhesive agent
The binder is used to aid in the bonding of the positive electrode active materials, conductive materials, etc. to each other and to the current collector. Specific examples thereof include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene Propylene Diene Monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, various copolymers thereof, and the like, which may be used alone or in combination of two or more thereof.
The binder may be present in an amount of 2.0 wt% to 4.0 wt%, specifically 2.2 wt% to 3.8 wt%, more specifically 2.3 wt% to 3.7 wt%, based on the total solids content of the positive electrode slurry composition. When the content of the binder satisfies the above range, the contact area between the binder and the lithium iron phosphate increases, whereby excellent positive electrode adhesion can be ensured.
(4) Conductive material
The conductive material is not particularly restricted so long as the conductive material does not cause chemical changes in the battery and has conductivity. For example, graphite may be used; carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, and the like; conductive fibers such as carbon fibers, metal fibers, and the like; a fluorocarbon compound; metal powder such as aluminum powder, nickel powder, etc.; conductive whiskers such as zinc oxide, potassium titanate, and the like; conductive metal oxides such as titanium oxide and the like; and conductive materials such as polyphenylene derivatives and the like. Specific examples of commercially available conductive materials include acetylene black type products (Chevron Chemical Company), dancarbo black (Denka Singapore Private Limited), gulf Oil Company products, ketjen black, EC type products (Armak Company), vulcan XC-72 (Cabot Company), super P (Timcal), and the like. Preferably, the conductive material may be carbon nanotubes. Carbon nanotubes are particularly preferred as the conductive material contained in the positive electrode slurry composition of the present application because the conductive network of carbon nanotubes can alleviate migration phenomenon of the binder during drying of the positive electrode slurry composition.
The content of the conductive material may be 0.1 to 3.0 wt%, specifically 0.2 to 2.0 wt%, more specifically 0.6 to 1.2 wt%, based on the total solids content of the positive electrode slurry composition. When the content of the conductive material satisfies the above range, the conductive network of the positive electrode is ensured, whereby the conductivity of the positive electrode can be improved.
(5) Solvent(s)
The solvent is intended to mix the above-mentioned positive electrode active material, binder, dispersant and/or conductive material. As the solvent, any solvent commonly used in the art may be used, and examples thereof include dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methyl-2-pyrrolidone (NMP), acetone, water, etc., which may be used alone or in combination of two or more thereof.
The content of the solvent may be such that the positive electrode slurry composition has an appropriate viscosity and an appropriate solid content. For example, the solvent may be present in an amount such that the solids content of the composition is from 40 to 75 wt%, specifically from 50 to 70 wt%, more specifically from 55 to 70 wt%. This content is relatively higher than that of other conventional positive electrode slurry compositions. When the solid content of the positive electrode slurry composition satisfies the above range, the time required for the slurry drying process in the production of the positive electrode is shortened, whereby the process cost can be reduced. Further, the composition has a viscosity at a coatable level, and the positive electrode active material layer formed of the composition has a thickness at a level or more, whereby excellent energy density can be ensured.
The positive electrode slurry composition according to the embodiment of the present application was prepared at 25℃and 10 °c -2 The viscosity measured at a shear rate of rpm may be 5,000cps to 20,000cps, specifically 6,000cps to 15,000cps, more specifically 8,000cps to 15,000cps. The positive electrode slurry composition having the viscosity within the above range may have excellent storage stability and coating workability. In addition, the positive electrode slurry composition may have a high solid content as compared with other positive electrode slurry compositions having the same viscosity, whereby the time required for the slurry drying process in the manufacture of the positive electrode is shortened, and thus the process cost may be reduced.
Positive electrode
Next, a positive electrode according to the present application will be described.
The positive electrode includes a positive electrode current collector and a positive electrode active material layer on at least one surface of the positive electrode current collector. In this case, the positive electrode active material layer includes a positive electrode active material, a conductive material, a binder, and a dispersant, wherein the positive electrode active material includes lithium iron phosphate, and the dispersant has a weight average molecular weight of 10,000g/mol to 150,000g/mol. The positive electrode may be formed using the positive electrode slurry composition described above. The positive electrode active material, the binder, the dispersant, and the conductive material have been described above.
Since the positive electrode according to the present application contains hydrogenated nitrile butadiene rubber as a dispersant, and the weight average molecular weight of the dispersant is 10,000g/mol to 150,000g/mol, the conductive material is agglomerated in a spherical form in the positive electrode. In the case of the positive electrode, the surface area of the agglomerated conductive material can be minimized as compared with the conductive material agglomerated in a linear form. Accordingly, the surface area of the positive electrode active material positioned adjacent to the agglomerated conductive material and thus not participating in the lithium intercalation/deintercalation reaction is minimized, whereby the discharge resistance of the lithium secondary battery can be reduced.
In the case of the positive electrode according to the present application, the conductive material is agglomerated in a spherical form, and therefore, the maximum axial length of the agglomerated area of the conductive material in the cross section of the positive electrode is 10 μm or less. Further, the ratio of the short axis length to the long axis length of the agglomerated area of the conductive material may be 0.1:1, preferably 0.2:1, more preferably 0.3:1.
when the agglomerated area of the conductive material satisfies the above range, the discharge resistance of the lithium secondary battery can be enhanced.
The agglomerated area of the conductive material in the cross section of the positive electrode can be confirmed by observing the cross section of the positive electrode using a scanning electron microscope (hereinafter referred to as "SEM"). In an SEM image or a Back Scattered Electron (BSE) image obtained by photographing a cross section of the positive electrode, lithium iron phosphate shows a bright contrast, and an agglomerated area of the conductive material shows a dark contrast. The length of the major and minor axes of the agglomerated areas of conductive material exhibiting dark contrast can be measured.
In the present application, a region having an area of 50 μm×50 μm in a cross section of the positive electrode is observed using SEM, and lengths of a major axis and a minor axis of the region shown in a dark image in an SEM image or a BSE image are measured.
The positive electrode current collector is not particularly limited as long as the positive electrode current collector does not cause chemical changes in the battery and has conductivity. As the current collector, for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel whose surface is treated with carbon, nickel, titanium, silver, or the like can be used.
The positive electrode current collector may have a thickness of 3 to 500 μm and may have fine irregularities formed on the surface thereof to increase adhesion with the positive electrode active material layer. For example, the positive electrode current collector may be used in any of various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a nonwoven fabric, and the like.
The positive electrode active material layer may be located on at least one surface of the positive electrode current collector and formed of the positive electrode slurry composition described above.
In addition to using the above-described positive electrode slurry composition, the positive electrode may be manufactured by a conventional method of manufacturing a positive electrode. Specifically, the positive electrode may be manufactured by coating a positive electrode slurry composition onto a positive electrode current collector, followed by drying and pressing.
As another method, the positive electrode may be manufactured by laminating the following film on a positive electrode current collector: the film is obtained by casting the positive electrode slurry composition on a separate support and removing it from the support.
Lithium secondary battery
Next, a lithium secondary battery according to the present application will be described.
The lithium secondary battery includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte.
The positive electrode in the lithium secondary battery has been described above. For example, the positive electrode includes a positive electrode active material, a conductive material, a binder, and a dispersant, wherein the positive electrode active material includes lithium iron phosphate, and the dispersant has a weight average molecular weight of 10,000g/mol to 150,000g/mol.
The anode may be manufactured, for example, by preparing an anode-forming composition including an anode active material, an anode binder, and an anode conductive material, and then coating the composition onto an anode current collector.
The anode active material is not particularly limited, and any compound capable of reversibly intercalating and deintercalating lithium may be used. Specific examples thereof include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fiber, amorphous carbon, highly crystalline carbon, and the like; a (semi) metallic material capable of alloying with lithium, such as Si, al, sn, pb, zn, bi, in, mg, ga, cd, si alloy, sn alloy, al alloy, etc.; and a composite material comprising a (semi) metallic material and a carbonaceous material. Examples of the low crystalline carbon include soft carbon and hard carbon, and examples of the high crystalline carbon include natural graphite, condensed graphite, pyrolytic carbon, mesophase pitch-like carbon fibers, mesophase carbon microspheres, mesophase pitch, and high-temperature calcined carbon, such as coke derived from petroleum or coal tar pitch, which may be used alone or in combination of two or more thereof. Further, as the anode active material, a lithium metal thin film may be used.
The anode conductive material is used to impart conductivity to the electrode, and any conductive material that does not cause chemical changes in the battery and has conductivity may be used without particular limitation. Specific examples thereof include graphite such as natural graphite, artificial graphite, etc.; carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, carbon fibers, carbon nanotubes, and the like; metal powders or fibers such as copper, nickel, aluminum, silver, etc.; conductive whiskers such as zinc oxide, potassium titanate, and the like; conductive metal oxides such as titanium oxide and the like; and conductive polymers such as polyphenylene derivatives and the like, which may be used alone or in combination of two or more thereof. The content of the anode conductive material may be generally 1 to 30 wt%, preferably 1 to 20 wt%, more preferably 1 to 10 wt%, with respect to the total weight of the anode active material layer.
The anode binder serves to enhance adhesion between anode active material particles and adhesion between anode active material and anode current collector. Specific examples thereof include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene Propylene Diene Monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, and various copolymers thereof, which may be used alone or in combination of two or more thereof. The content of the anode binder may be 1 to 30 wt%, preferably 1 to 20 wt%, more preferably 1 to 10 wt%, with respect to the total weight of the anode active material layer.
On the other hand, the anode current collector is not particularly limited as long as the anode current collector does not cause chemical changes in the battery and has high conductivity. As the negative electrode current collector, for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, or copper or stainless steel whose surface is treated with carbon, nickel, titanium, silver, or the like, aluminum-cadmium alloy, or the like can be used.
Further, the thickness of the anode current collector may be generally 3 μm to 500 μm. As with the positive electrode current collector, the negative electrode current collector may have fine irregularities formed on the surface thereof to increase adhesion with the negative electrode active material. For example, the anode current collector may be used in any of various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a nonwoven fabric, and the like.
On the other hand, as the separator in the lithium secondary battery, any separator commonly used as a separator in a lithium secondary battery may be used without particular limitation, and in particular, a separator exhibiting low resistance to electrolyte ion migration and having excellent electrolyte impregnation ability is preferable. Specifically, a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene/butene copolymer, an ethylene/hexene copolymer, an ethylene/methacrylate copolymer, or the like, or a stacked structure having two or more layers thereof may be used. In addition, a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting glass fibers, polyethylene terephthalate fibers, or the like may be used. Further, the separator may be a porous film having a pore diameter of 0.01 μm to 10 μm and a thickness of 5 μm to 300 μm.
On the other hand, in the lithium secondary battery, the electrolyte may contain an organic solvent and a lithium salt, which are generally used in the electrolyte, and there is no particular limitation on them.
As the organic solvent, any solvent that can function as a medium through which ions participating in the electrochemical reaction of the battery can move can be used without particular limitation. Specifically, as the organic solvent, an ester solvent such as methyl acetate, ethyl acetate, γ -butyrolactone, epsilon-caprolactone, or the like; ether solvents such as dibutyl ether, tetrahydrofuran, and the like; ketone solvents such as cyclohexanone and the like; aromatic hydrocarbon solvents such as benzene, fluorobenzene and the like; or carbonate solvents such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylmethyl carbonate (MEC), ethylmethyl carbonate (EMC), ethylene Carbonate (EC), propylene Carbonate (PC), and the like.
Among those listed above, a carbonate-based solvent is preferable, and more preferable is a mixture of a cyclic carbonate-based compound (e.g., EC, PC, etc.) having high ion conductivity and high dielectric constant with a linear carbonate-based compound (e.g., EMC, DMC, DEC, etc.) having low viscosity, which can improve charge/discharge performance of the battery.
As the lithium salt, any compound capable of providing lithium ions used in a lithium secondary battery may be used without particular limitation. Specifically, as the lithium salt, liPF can be used 6 、LiClO 4 、LiAsF 6 、LiBF 4 、LiSbF 6 、LiAlO 4 、LiAlCl 4 、LiCF 3 SO 3 、LiC 4 F 9 SO 3 、LiN(C 2 F 5 SO 3 ) 2 、LiN(C 2 F 5 SO 2 ) 2 、LiN(CF 3 SO 2 ) 2 、LiCl、LiI、LiB(C 2 O 4 ) 2 Etc. The lithium salt is preferably contained in the electrolyte at a concentration of about 0.6mol% to 2 mol%.
In addition to the above electrolyte components, the electrolyte may further contain one or more additives such as pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, (formal) glyme, hexamethylphosphoric triamide, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted for the purpose of improving the life characteristics of the battery, suppressing the decrease in the capacity of the battery, improving the discharge capacity of the battery, etcOxazolidinone, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride, and the like. In this case, the content of the additive may be 0.1 to 5 wt% with respect to the total weight of the electrolyte.
The lithium secondary battery according to the present application may be manufactured by: the separator is interposed between the positive electrode and the negative electrode to form an electrode assembly, the electrode assembly is placed in a cylindrical battery case or a prismatic battery case, and an electrolyte is injected. Alternatively, the lithium secondary battery may be manufactured by: the electrode assemblies were stacked, the electrode assemblies were impregnated with an electrolyte, the resulting was placed in a battery case, and the battery case was sealed.
In the manufacture of the lithium secondary battery according to the present application, the electrode assembly may be dried to remove one or more organic solvents selected from the group consisting of N-methyl-2-pyrrolidone (NMP), acetone, ethanol, PC, EMC, EC, and DMC used in the manufacture of the positive electrode. When an electrolyte having the same composition as the organic solvent used in the manufacture of the positive electrode is used, the drying process of the electrode assembly may be omitted.
Unlike the above-described lithium secondary battery, the lithium secondary battery according to another embodiment of the application may be a solid-state battery.
As the battery case, any battery case generally used in the art may be used, and there is no limitation on the external shape according to the use of the battery. For example, the outer shape of the battery case may be cylindrical, prismatic, pouch-shaped, coin-shaped, etc., using a can.
The lithium secondary battery according to the present application is useful in the following fields because it stably exhibits excellent discharge capacity, output characteristics, and capacity retention: portable devices such as mobile phones, notebook computers, digital cameras, etc.; an Energy Storage System (ESS); and electric vehicles, such as Hybrid Electric Vehicles (HEVs), and the like.
The battery resistance (SOC 50 discharge resistance) of the lithium secondary battery according to the present application, which is a value obtained by dividing a voltage drop value displayed when a discharge pulse is applied for 10 seconds in a state of charge (SOC) of 50% and at 2.5C, by a current value, may be 1.7mΩ or less, specifically 1.1mΩ to 1.7mΩ, more specifically 1.1mΩ to 1.6mΩ.
Since the positive electrode active material in the lithium secondary battery contains lithium iron phosphate and the weight average molecular weight of the dispersant is 10,000g/mol to 150,000g/mol, it is possible to exhibit battery resistance satisfying the above range. Specifically, when a low molecular weight dispersant is included in the positive electrode slurry composition, the conductive material is agglomerated in a spherical form in the positive electrode, whereby the surface area of the agglomerated conductive material can be minimized as compared with the conductive material agglomerated in a linear form. As a result, the surface area of the positive electrode active material that is positioned adjacent to the agglomerated conductive material and thus does not participate in the lithium intercalation/deintercalation reaction is minimized, whereby the battery resistance of the lithium secondary battery manufactured using the positive electrode slurry composition can be reduced to within the above-described range.
Hereinafter, the present application will be described in further detail with reference to examples. However, the following examples are provided only to illustrate the present application, and the scope of the present application is not limited to the following examples.
Example 1
(1) Preparation of Positive electrode slurry composition
Will be used asMean particle diameter D of positive electrode active material 50 1 μm and BET specific surface area of 11m 2 LiFePO/g 4 Carbon Nanotubes (CNT) as a conductive material, polyvinylidene fluoride (PVdF) as a binder, and hydrogenated nitrile butadiene rubber (H-NBR) having a weight average molecular weight (Mw) of 40,000g/mol as a dispersant were added to an N-methylpyrrolidone (NMP) solvent, and then mixed at 2500rpm using a homomixer (homodisperser) for 60 minutes to prepare a positive electrode slurry composition.
Positive electrode active material, conductive material, binder and dispersant in positive electrode slurry composition as 95.68:0.8:3.0:0.52 weight percent, and the solid content in the positive electrode slurry composition was 60 weight percent.
(2) Manufacturing of positive electrode
The prepared positive electrode slurry composition was coated on a 15 μm thick aluminum film using a slot die coater, and then dried in vacuo at 130 ℃ for 10 hours. Then, pressing was performed so that the porosity of the positive electrode active material layer was 28% to manufacture a positive electrode. The positive electrode active material layer had a thickness of 98 μm, a width of 33mm, a length of 50mm, and a loading amount of 3.6mAh/cm 2 。
(3) Manufacturing of lithium secondary battery
First, artificial graphite as a negative electrode active material, super C as a conductive material, and SBR/CMC as a binder were mixed at 96:1:3 to prepare a negative electrode slurry, and coating the slurry onto one surface of a copper current collector, drying at 130 deg.c, and pressing so that the porosity of the negative electrode active material layer is 29% to manufacture a negative electrode having a width of 34mm and a length of 51 mm.
Next, a polypropylene separator having a thickness of 18 μm was interposed between the fabricated positive electrode and negative electrode to fabricate an electrode assembly. The electrode assembly was housed in an aluminum pouch-type battery case, into which 230g of 1.0M LiPF was injected 6 And 2 wt% of an electrolyte of Vinylene Carbonate (VC) dissolved in an organic solvent (EC/EMC/dmc=3:3:4 volume ratio), and vacuum-sealing the battery case. The electrolyte was aged for one day, activated at 7.9mAh for 3 hours, and then aged for 3 more days. Finally, go intoA degassing process is performed to manufacture a lithium secondary battery.
Examples 2 to 3
A positive electrode slurry composition and a lithium secondary battery were manufactured in the same manner as in example 1, except that H-NBR having a weight average molecular weight (Mw) described in table 1 was used as a dispersant.
Comparative example 1
A positive electrode slurry composition and a lithium secondary battery were produced in the same manner as in example 1, except that H-NBR having a weight average molecular weight (Mw) of 220,000g/mol was used as a dispersant, and the solid content in the positive electrode slurry composition was 58 wt%.
Comparative example 2
A positive electrode slurry composition and a lithium secondary battery were manufactured in the same manner as in comparative example 1, except that the solid content in the positive electrode slurry composition was 60 wt%.
TABLE 1
Experimental example 1 viscosity measurement
The viscosity of each of the positive electrode slurry compositions prepared in examples 1 to 3 and comparative examples 1 and 2 was measured, and the measurement results are shown in table 2 below.
Specifically, each of the positive electrode slurry compositions prepared in examples 1 to 3 and comparative examples 1 and 2 was cooled at room temperature and 1% relative humidity for one hour, and then cooled at 25℃and 10 using a viscometer (Brookfield Co.) -2 The viscosity of the positive electrode slurry composition was measured at a shear rate of rpm. The viscosity measurement was performed within 2 hours, including the cooling time after the positive electrode slurry composition was prepared.
Experimental example 2 confirmation of agglomeration morphology of conductive Material on Cross section of Positive electrode
Areas having an area of 50 μm×50 μm in the cross section of each of the positive electrodes manufactured in examples 1 to 3 and comparative example 1 were observed using a Scanning Electron Microscope (SEM), and the agglomerated form of the conductive material on the cross section of the positive electrode was confirmed. SEM images are shown in fig. 1 and 4, and the agglomerated morphology of the conductive material on the cross section of the positive electrode is shown in table 2 below.
Fig. 1 is an SEM image of a cross section of a positive electrode in a lithium secondary battery of example 1, fig. 2 is an SEM image of a cross section of a positive electrode in a lithium secondary battery of example 2, fig. 3 is an SEM image of a cross section of a positive electrode in a lithium secondary battery of example 3, and fig. 4 is an SEM image of a cross section of a positive electrode in a lithium secondary battery of comparative example 1.
In fig. 1 to 4, lithium iron phosphate is shown as a bright portion, and agglomerated areas of the conductive material are shown as dark shadows.
As shown in fig. 1 to 2, in the cross sections of the positive electrodes of example 1 and example 2, it was confirmed that the region where the conductive material agglomerated in a linear form was not found, and the conductive material agglomerated in a spherical form. As shown in fig. 3, in the case of the cross section of the positive electrode of example 3, there are a region where the conductive material is agglomerated in a spherical form and a region where the conductive material is agglomerated in a linear form, but the maximum axial length of the region where the conductive material is agglomerated in a linear form is 10 μm or less. On the other hand, as shown in fig. 4, in the cross section of the positive electrode of comparative example 1, a linear conductive material agglomerated region having a length of 1 μm or more was found, and three conductive material agglomerated regions having a long axis length of more than 10 μm were also found.
Experimental example 3 measurement of cell resistance of lithium Secondary cell
The battery resistances of the respective lithium secondary batteries prepared in examples 1 to 3 and comparative examples 1 and 2 were measured, and the measurement results are shown in table 2 below.
Specifically, for each of the lithium secondary batteries manufactured in examples 1 to 3 and comparative examples 1 and 2, a value obtained by dividing a voltage drop value displayed when a discharge pulse was applied for 10 seconds in a state of charge (SOC) of 50% and at 2.5C by a current value was measured as a battery resistance (SOC 50 discharge resistance).
TABLE 2
| Positive electrode slurry composition | Cross section of positive electrode | Lithium secondary battery | |
| Viscosity (cps) | Agglomeration morphology of conductive materials | Battery resistor (mΩ) | |
| Example 1 | 11,900 | Spherical shape | 1.5 |
| Example 2 | 10,500 | Spherical shape | 1.5 |
| Example 3 | 12,400 | Sphere/wire shape | 1.5 |
| Comparative example 1 | 8,900 | Linear shape | 1.8 |
| Comparative example 2 | 23,000 | (no observation) | (not measurable) |
Referring to table 2, it can be confirmed that the positive electrode slurry composition of comparative example 2, in which the weight average molecular weight of the dispersant exceeds 150,000g/mol, has significantly higher viscosity than the positive electrode slurry composition of example 1, based on the same solid content.
In the case of comparative example 2, since the viscosity of the positive electrode slurry composition was too high to cause clogging of a transfer pipe connected to the slot die coater with the positive electrode slurry composition, the slurry composition could not be discharged from the slot die coater by a conventional pump pressure. In order to discharge the positive electrode slurry composition from the slot die coater, a high pump pressure needs to be applied to the slot die coater, and thus, an excessive pump pressure is applied. Therefore, since the positive electrode slurry composition cannot be coated at the same loading amount as in example 1, it is impossible to manufacture a positive electrode, and thus it is also impossible to measure the battery resistance of the lithium secondary battery.
Although the positive electrode slurry composition of comparative example 1 in which the weight average molecular weight of the dispersant exceeds 150,000g/mol has a low viscosity, it has a lower solid content than the positive electrode slurry composition of example 1, and thus it takes a long time to dry the composition in the manufacture of the positive electrode, thus increasing the process cost.
Further, it was confirmed that the lithium secondary battery of comparative example 1 exhibited higher battery resistance than the lithium secondary battery of example 1. It is presumed that such a result is obtained because, in the case of comparative example 1, as shown in fig. 2, the conductive material is agglomerated in a linear form in the positive electrode to increase the surface area of the agglomerated conductive material, and thus the surface area of the positive electrode active material that is positioned adjacent to the agglomerated conductive material and thus does not participate in the lithium intercalation/deintercalation reaction is increased.
Claims (12)
1. A positive electrode slurry composition, the positive electrode slurry composition comprising: a positive electrode active material, a dispersing agent, a conductive material, a binder and a solvent,
wherein the positive electrode active material contains lithium iron phosphate, and
the dispersant has a weight average molecular weight of from 10,000g/mol to 150,000g/mol.
2. The positive electrode slurry composition according to claim 1, wherein the lithium iron phosphate is a compound represented by the following chemical formula 1,
[ chemical formula 1]
Li 1+a Fe 1-x M x (PO 4-b )X b
Wherein, in the chemical formula 1,
m is any one or more than two elements selected from Al, mg, ni, co, mn, ti, ga, cu, V, nb, zr, ce, in, zn and Y,
x is any one or more elements selected from F, S and N, and
a. b and x respectively satisfy-0.5.ltoreq.a.ltoreq.0.5, 0.ltoreq.b.ltoreq.0.1 and 0.ltoreq.x.ltoreq.0.5.
3. The positive electrode slurry composition according to claim 1, wherein the dispersant is hydrogenated nitrile butadiene rubber.
4. The positive electrode slurry composition according to claim 1, wherein the content of the dispersant is 0.2 parts by weight to 1.0 parts by weight with respect to 100 parts by weight of solids in the positive electrode slurry composition.
5. The positive electrode slurry composition according to claim 1, wherein a solid content in the positive electrode slurry composition is 40 to 75% by weight.
6. The positive electrode slurry composition according to claim 1, wherein the positive electrode slurry composition is at 25 ℃ and 10 °c -2 The viscosity measured at rpm is 5,000cps to 20,000cps.
7. The positive electrode slurry composition according to claim 1, wherein the content of the conductive material is 0.1 to 3.0 parts by weight with respect to 100 parts by weight of solids in the positive electrode slurry composition.
8. The positive electrode slurry composition according to claim 1, wherein the content of the binder is 2.0 parts by weight to 4.0 parts by weight with respect to 100 parts by weight of solids in the positive electrode slurry composition.
9. A lithium secondary battery comprising a positive electrode,
wherein the positive electrode comprises a positive electrode active material, a dispersing agent, a conductive material and a binder,
wherein the positive electrode active material contains lithium iron phosphate, and
wherein, in the cross section of the positive electrode, the maximum axial length of the agglomeration region of the conductive material is 10 μm or less.
10. The lithium secondary battery according to claim 9, wherein the dispersant has a weight average molecular weight of 10,000g/mol to 150,000g/mol.
11. The lithium secondary battery according to claim 9, wherein the dispersant is hydrogenated nitrile butadiene rubber.
12. The lithium secondary battery according to claim 9, wherein the SOC50 discharge resistance of the lithium secondary battery is 1.7mΩ or less.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10-2021-0187722 | 2021-12-24 | ||
| KR10-2022-0179775 | 2022-12-20 | ||
| KR1020220179775A KR20230098037A (en) | 2021-12-24 | 2022-12-20 | Positive electrode slurry composition and lithium secondary battery using the same |
| PCT/KR2022/020996 WO2023121315A1 (en) | 2021-12-24 | 2022-12-21 | Cathode slurry composition, and lithium secondary battery manufactured using same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116918094A true CN116918094A (en) | 2023-10-20 |
Family
ID=88361365
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280015253.9A Pending CN116918094A (en) | 2021-12-24 | 2022-12-21 | Positive electrode slurry composition and lithium secondary battery manufactured using same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116918094A (en) |
-
2022
- 2022-12-21 CN CN202280015253.9A patent/CN116918094A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11038175B2 (en) | Positive electrode active material pre-dispersion composition including hydrogenated nitrile butadiene rubber as dispersant, positive electrode for secondary battery, and lithium secondary battery including the positive electrode | |
| KR102323808B1 (en) | Method for preparing positive electrode slurry composition for secondary battery, positive electrode for secondary battery by using the same, and lithium secondary battery comprising the same | |
| KR102314626B1 (en) | Electrode for secondary battery, method for preparing the same, and lithium secondary battery comprising the same | |
| US11888153B2 (en) | Method for preparing positive electrode active material for secondary battery, positive electrode active material thus prepared and lithium secondary battery including the same | |
| CN113646930A (en) | Positive electrode active material for secondary battery, method for preparing same, and secondary battery positive electrode comprising same | |
| CN111989805A (en) | Positive electrode material for lithium secondary battery, and positive electrode for lithium secondary battery and lithium secondary battery comprising same | |
| US20230073433A1 (en) | Positive Electrode Material for Lithium Secondary Battery, and Positive Electrode and Lithium Secondary Battery Which Include the Same | |
| KR20210079178A (en) | Positive electrode optimized for improving high-temperature life characteristics and secondary battery comprising the same | |
| KR20210067735A (en) | Positive Electrode for Secondary Battery Comprising Flake Graphite And Secondary Battery Comprising the Same | |
| EP4071861A1 (en) | Aqueous slurry for positive electrode, positive electrode composition, lithium-ion secondary battery including said positive electrode composition, and methods for manufacturing same | |
| CN116210102A (en) | Negative electrode material, and negative electrode and secondary battery comprising same | |
| CN114730867A (en) | Method for manufacturing positive electrode material for secondary battery | |
| KR20200031304A (en) | Positive electrode active material for secondary battery, method for preparing the same and lithium secondary battery comprising the same | |
| EP4016674A1 (en) | Method for producing positive electrode active material for lithium secondary battery, and positive electrode active material produced thereby for lithium secondary battery | |
| CN115485879A (en) | Positive electrode and lithium secondary battery comprising same | |
| US20230207807A1 (en) | Positive Electrode Slurry Composition and Lithium Secondary Battery Manufactured Using the Same | |
| CN114747041A (en) | Positive electrode optimized for improved high temperature life characteristics and secondary battery comprising the same | |
| CN116918094A (en) | Positive electrode slurry composition and lithium secondary battery manufactured using same | |
| KR102652282B1 (en) | Positive electrode slurry composition, positive electrode and lithium secondary battery using the same | |
| EP4322253A1 (en) | Cathode slurry composition, cathode manufactured using same, and lithium secondary battery | |
| US20230207798A1 (en) | Positive Electrode Slurry Composition, Positive Electrode and Lithium Secondary Battery Manufactured Using the Same | |
| EP4322256A1 (en) | Positive electrode and lithium secondary battery manufactured using same | |
| US20230021692A1 (en) | Negative electrode for lithium secondary battery, method for preparing negative electrode for lithium secondary battery, and lithium secondary battery including negative electrode | |
| KR20230098037A (en) | Positive electrode slurry composition and lithium secondary battery using the same | |
| CN117203793A (en) | Positive electrode slurry composition, positive electrode manufactured using same, and lithium secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |