CN117280490A - Positive electrode slurry composition, positive electrode manufactured using same, and lithium secondary battery - Google Patents
Positive electrode slurry composition, positive electrode manufactured using same, and lithium secondary battery Download PDFInfo
- Publication number
- CN117280490A CN117280490A CN202280033762.4A CN202280033762A CN117280490A CN 117280490 A CN117280490 A CN 117280490A CN 202280033762 A CN202280033762 A CN 202280033762A CN 117280490 A CN117280490 A CN 117280490A
- Authority
- CN
- China
- Prior art keywords
- positive electrode
- slurry composition
- electrode slurry
- active material
- binder
- 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 112
- 239000011267 electrode slurry Substances 0.000 title claims abstract description 95
- 229910052744 lithium Inorganic materials 0.000 title claims description 32
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims description 31
- 239000007774 positive electrode material Substances 0.000 claims abstract description 59
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 54
- 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
- 239000011230 binding agent Substances 0.000 claims abstract description 52
- 239000002033 PVDF binder Substances 0.000 claims abstract description 51
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims abstract description 51
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 35
- 239000002270 dispersing agent Substances 0.000 claims abstract description 31
- 239000011247 coating layer Substances 0.000 claims abstract description 20
- 239000002904 solvent Substances 0.000 claims abstract description 20
- 239000010410 layer Substances 0.000 claims description 19
- 239000002245 particle Substances 0.000 claims description 19
- 239000000126 substance Substances 0.000 claims description 15
- 239000007787 solid Substances 0.000 claims description 14
- 239000003792 electrolyte Substances 0.000 claims description 13
- 238000005160 1H NMR spectroscopy Methods 0.000 claims description 12
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- 229920001519 homopolymer Polymers 0.000 claims description 6
- 239000000853 adhesive Substances 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 5
- 230000001070 adhesive effect Effects 0.000 claims description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 229920000459 Nitrile rubber Polymers 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
- 238000013421 nuclear magnetic resonance imaging Methods 0.000 abstract 1
- 239000004020 conductor Substances 0.000 description 25
- 238000001879 gelation Methods 0.000 description 16
- -1 polyphenylene Polymers 0.000 description 15
- 238000000576 coating method Methods 0.000 description 13
- 239000011248 coating agent Substances 0.000 description 12
- 238000005481 NMR spectroscopy Methods 0.000 description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 11
- 229920001577 copolymer Polymers 0.000 description 11
- 125000000524 functional group Chemical group 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 10
- 229910052739 hydrogen Inorganic materials 0.000 description 10
- 239000001257 hydrogen Substances 0.000 description 10
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 9
- 230000002776 aggregation Effects 0.000 description 7
- 239000006183 anode active material Substances 0.000 description 7
- 238000002360 preparation method Methods 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 6
- 238000005054 agglomeration Methods 0.000 description 6
- 150000001993 dienes Chemical class 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 239000000178 monomer Substances 0.000 description 6
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 5
- 239000005977 Ethylene Substances 0.000 description 5
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 239000010408 film Substances 0.000 description 5
- 229910052759 nickel Inorganic materials 0.000 description 5
- 239000003960 organic solvent Substances 0.000 description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-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
- 239000002041 carbon nanotube Substances 0.000 description 4
- 229910021393 carbon nanotube Inorganic materials 0.000 description 4
- 239000003575 carbonaceous material Substances 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 239000000835 fiber Substances 0.000 description 4
- 238000005227 gel permeation chromatography Methods 0.000 description 4
- 229910003002 lithium salt Inorganic materials 0.000 description 4
- 159000000002 lithium salts Chemical class 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 125000000896 monocarboxylic acid group Chemical group 0.000 description 4
- 239000004745 nonwoven fabric Substances 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
- 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
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 3
- 239000006230 acetylene black Substances 0.000 description 3
- 239000011884 anode binding agent Substances 0.000 description 3
- 239000004917 carbon fiber Substances 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 3
- 238000001035 drying Methods 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
- 229910001416 lithium ion Inorganic materials 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910021382 natural graphite Inorganic materials 0.000 description 3
- 150000002825 nitriles Chemical class 0.000 description 3
- 239000011148 porous material Substances 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
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-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
- 229920000265 Polyparaphenylene Polymers 0.000 description 2
- 239000004793 Polystyrene 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
- 229920002472 Starch Polymers 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- SOXUFMZTHZXOGC-UHFFFAOYSA-N [Li].[Mn].[Co].[Ni] Chemical compound [Li].[Mn].[Co].[Ni] SOXUFMZTHZXOGC-UHFFFAOYSA-N 0.000 description 2
- 239000011149 active material Substances 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 229910021383 artificial graphite Inorganic materials 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
- 238000009831 deintercalation Methods 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
- 230000000694 effects Effects 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
- 239000006260 foam Substances 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 239000006232 furnace black Substances 0.000 description 2
- 238000009830 intercalation Methods 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
- 239000000463 material Substances 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
- 230000005012 migration Effects 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 238000001208 nuclear magnetic resonance pulse sequence Methods 0.000 description 2
- 229920001542 oligosaccharide Polymers 0.000 description 2
- 150000002482 oligosaccharides Chemical class 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 229920006254 polymer film Polymers 0.000 description 2
- 229920002223 polystyrene Polymers 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000008107 starch Substances 0.000 description 2
- 235000019698 starch Nutrition 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 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
- 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
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- 229910000925 Cd alloy Inorganic materials 0.000 description 1
- 229920002943 EPDM rubber Polymers 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
- 229920002153 Hydroxypropyl cellulose Polymers 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
- 229910012513 LiSbF 6 Inorganic materials 0.000 description 1
- 101150058243 Lipf gene Proteins 0.000 description 1
- 229910000572 Lithium Nickel Cobalt Manganese Oxide (NCM) Inorganic materials 0.000 description 1
- GYCMBHHDWRMZGG-UHFFFAOYSA-N Methylacrylonitrile Chemical compound CC(=C)C#N GYCMBHHDWRMZGG-UHFFFAOYSA-N 0.000 description 1
- 244000179970 Monarda didyma Species 0.000 description 1
- 235000010672 Monarda didyma Nutrition 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol 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
- 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
- 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
- 230000000996 additive effect Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 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
- 238000011088 calibration curve Methods 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000006182 cathode active material Substances 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000012461 cellulose resin Substances 0.000 description 1
- 238000006243 chemical reaction Methods 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
- 238000007796 conventional method Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 150000004292 cyclic ethers Chemical class 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 239000011883 electrode binding agent Substances 0.000 description 1
- 238000010294 electrolyte impregnation Methods 0.000 description 1
- 239000003480 eluent Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 239000003759 ester based solvent Substances 0.000 description 1
- 239000004210 ether based solvent Substances 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 229920001973 fluoroelastomer Polymers 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 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
- 239000001863 hydroxypropyl cellulose Substances 0.000 description 1
- 235000010977 hydroxypropyl cellulose Nutrition 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000002687 intercalation Effects 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
- PTVWPYVOOKLBCG-ZDUSSCGKSA-N levodropropizine Chemical compound C1CN(C[C@H](O)CO)CCN1C1=CC=CC=C1 PTVWPYVOOKLBCG-ZDUSSCGKSA-N 0.000 description 1
- 239000007788 liquid Substances 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
- 238000002844 melting Methods 0.000 description 1
- 239000011302 mesophase pitch Substances 0.000 description 1
- 150000002739 metals Chemical class 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
- 239000007773 negative electrode material Substances 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
- 229920000573 polyethylene 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
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 1
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 1
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 1
- 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
- 239000004627 regenerated cellulose Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000005060 rubber Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 239000005720 sucrose Substances 0.000 description 1
- 229920005608 sulfonated EPDM Polymers 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 239000011269 tar Substances 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
Landscapes
- Battery Electrode And Active Subsutance (AREA)
Abstract
The present invention relates to a positive electrode slurry composition comprising a positive electrode active material, a binder, a dispersant, and a solvent, wherein the positive electrode active material comprises a lithium iron phosphate having a carbon coating layer on the surface thereof, and the binder comprises polyvinylidene fluoride satisfying the following formula 1 [ formula 1]]0≤{(2A+B)/(C+D)}×100<0.2 wherein A, B, C and D are obtained by polyvinylidene fluoride 1 The respective peaks shown at 11.5ppm to 12.8ppm, 3.9ppm to 4.2ppm, 2.6ppm to 3.2ppm and 2.1ppm to 2.35ppm as measured by H-NMRIs a part of the total integrated area of the lens.
Description
Technical Field
The present application claims priority from korean patent application No. 10-2021-0187191, filed 24 at 12 months of 2021, and korean patent application No. 10-2022-0178234, filed 19 at 12 months of 2022, the disclosures of which are incorporated herein by reference.
The present invention relates to a positive electrode slurry composition and a positive electrode and a lithium secondary battery manufactured using the same, and more particularly, to a positive electrode slurry composition having smooth electrode coating processability and a positive electrode 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, 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 the above listed materials, lithium iron phosphate is inexpensive because it is abundant in resources and contains low cost material iron. In addition, 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, high temperature stability and high temperature life characteristics can be improved.
However, lithium iron phosphate has problems of poor lithium mobility and low conductivity compared to lithium transition metal oxides such as lithium nickel cobalt manganese oxide. Therefore, in general, lithium iron phosphate has been used after improving mobility of lithium ions by shortening a moving path of lithium by reducing an average particle diameter of the lithium iron phosphate and improving conductivity by coating a surface of the lithium iron phosphate with carbon.
However, since the carbon coating layer formed on the surface of the lithium iron phosphate is bound to the functional group of the binder, there is a problem in that the positive electrode slurry composition is gelled during the preparation of the positive electrode slurry. In addition, when the specific surface area of the lithium iron phosphate particles increases due to the small particle size of the lithium iron phosphate, the area of the sites where bonding may occur increases, whereby gelation occurs more seriously. Therefore, it becomes difficult to apply the composition to the current collector, and the thickness and/or surface of the positive electrode active material layer is unevenly formed even when the composition is applied, whereby the output performance and life characteristics of the manufactured battery may be reduced.
Therefore, a technique for suppressing gelation of a positive electrode slurry composition containing lithium iron phosphate and a binder is required.
Disclosure of Invention
Technical problem
The present invention aims to provide a positive electrode slurry composition having smooth electrode coating processability by suppressing gelation of a positive electrode slurry containing lithium iron phosphate.
The present invention also relates to providing a positive electrode manufactured using the positive electrode slurry composition and a lithium secondary battery including the positive electrode.
Technical proposal
According to an embodiment of the present invention, there is provided a positive electrode slurry composition including a positive electrode active material, a binder, a dispersant, and a solvent, wherein the positive electrode active material includes lithium iron phosphate having a carbon coating layer on a surface thereof, and the binder includes polyvinylidene fluoride satisfying the following formula 1.
According to another embodiment of the present invention, there is provided a positive electrode including a positive electrode current collector and a positive electrode active material layer on at least one surface of the positive electrode current collector, wherein the positive electrode active material layer includes a positive electrode active material, a binder, and a dispersant, the positive electrode active material includes a lithium iron phosphate having a carbon coating layer on a surface thereof, and the binder includes polyvinylidene fluoride satisfying the following mathematical formula 1.
According to still another embodiment of the present invention, there is provided a lithium secondary battery including a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode includes a positive electrode active material including lithium iron phosphate having a carbon coating layer on a surface thereof, a binder including polyvinylidene fluoride satisfying the following mathematical formula 1, and a dispersant.
[ mathematics 1]
0≤{(2A+B)/(C+D)}×100<0.2
(A, B, C and D are obtained by polyvinylidene fluoride) 1 The integrated areas of the individual peaks shown at 11.5ppm to 12.8ppm, 3.9ppm to 4.2ppm, 2.6ppm to 3.2ppm and 2.1ppm to 2.35ppm as measured by H-NMR
Advantageous effects
Since the positive electrode slurry composition according to the present invention contains polyvinylidene fluoride satisfying mathematical formula 1 as a binder, hydrogen bonding between hydrogen contained in the carbon coating layer on the surface of lithium iron phosphate and functional groups contained in the binder is reduced, so that gelation of the composition can be prevented.
Further, since gelation of the positive electrode slurry composition is prevented, excellent coating workability can be exhibited.
In addition, since the positive electrode formed of the positive electrode slurry composition includes the positive electrode active material layer having minimized surface defects and uniform thickness, the lithium secondary battery manufactured using the positive electrode can exhibit excellent output performance and excellent life characteristics.
Drawings
FIG. 1 is a schematic diagram of the polyvinylidene fluoride used in examples 1 to 3 1 H NMR chart.
FIG. 2 is a graph showing the polyvinylidene fluoride used in comparative example 1 1 H NMR chart.
Fig. 3 is a graph showing measurement results of viscosity as a function of shear rate for each of the positive electrode slurry compositions prepared in examples 1 to 3 and comparative example 1.
Detailed Description
The advantages and features of the present invention and methods for practicing the present invention will be apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings. However, the present invention 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 invention to those skilled in the art to which the invention pertains, and the invention 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 invention 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 invention. In this specification, the singular forms may include the plural unless specifically stated in the phrase. As used herein, the terms "comprising" and/or "comprises" 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 is to 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 stated 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 liquid nitrogen temperature (77K) using the BELSORP-mini ii available from BEL japan.
In the present specification, "weight average molecular weight (M w ) "means a converted value relative to standard polystyrene measured by Gel Permeation Chromatography (GPC). Specifically, the weight average molecular weight is a value obtained by converting a value measured using GPC under the following conditions, and a calibration curve is made using standard polystyrene of an Agilent (Agilent) system.
< measurement condition >
An analyzer: agilent GPC (Agilent 1200 series, U.S.A.)
Column: two connected PL Mixed B columns
Column temperature: 40 DEG C
Eluent: tetrahydrofuran (THF)
Flow rate: 1.0 mL/min
Concentration: 1mg/mL (100. Mu.L injection)
In the present specification, polyvinylidene fluoride (PVdF) 1 H NMR using NMR equipment (Bruker 600MHz available from Bruker) at ns=1k, dl=3s, temperature of pulse sequences zg30, 298K and DMSO-d 6 Measurement under solvent conditions.
In this specification, the shear viscosity of the positive electrode slurry composition was measured at 25 ℃ using a rheometer (DHR 2 available from TA Instruments) after placing 10ml of the positive electrode slurry composition into a concentric cylinder-type accessory of the rheometer.
Hereinafter, embodiments of the present invention will be described in detail.
Positive electrode slurry composition
A positive electrode slurry composition according to an embodiment of the present invention includes a positive electrode active material, a binder, a dispersant, and a solvent, wherein the positive electrode active material includes lithium iron phosphate having a carbon coating layer on a surface thereof, and the binder includes polyvinylidene fluoride satisfying the following mathematical formula 1.
[ mathematics 1]
0≤{(2A+B)/(C+D)}×100<0.2
(A, B, C and D are obtained by polyvinylidene fluoride) 1 The integrated areas of the individual peaks shown at 11.5ppm to 12.8ppm, 3.9ppm to 4.2ppm, 2.6ppm to 3.2ppm and 2.1ppm to 2.35ppm as measured by H-NMR
During the preparation of the positive electrode slurry composition, a mixture including a positive electrode active material, a binder, a conductive material, a dispersant, and a solvent is stirred, and during the stirring, a shearing force is applied to the positive electrode slurry composition. In this case, since the carbon coating layer formed on the surface of the lithium iron phosphate is bound to the functional group of the binder, there is a problem in that the positive electrode slurry composition is gelled during the preparation of the positive electrode slurry. In addition, when the specific surface area of the lithium iron phosphate particles increases due to the small particle size of the lithium iron phosphate, the area of the sites where bonding may occur increases, whereby gelation occurs more seriously. Therefore, it becomes difficult to apply the composition to the current collector, and the thickness and/or surface of the positive electrode active material layer is unevenly formed even when the composition is applied, whereby the output performance and life characteristics of the manufactured battery may be reduced.
As a result of long-term studies to solve the above problems, the inventors of the present invention found that the use of a binder satisfying specific conditions together with lithium iron phosphate reduces hydrogen bonding between hydrogen contained in a carbon coating layer on the surface of lithium iron phosphate and functional groups contained in the binder, thereby enabling suppression of gelation phenomenon. This will be described in detail below.
(1) Positive electrode active material
The positive electrode active material includes lithium iron phosphate, and the lithium iron phosphate may be a compound represented by the following chemical formula 1. When the positive electrode active material contains lithium iron phosphate, the stability of the positive electrode containing the positive electrode active material is significantly improved, and thus the ignition of the lithium secondary battery containing the positive electrode can 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 and Y,
x comprises any one or more elements selected from F, S and N, and
a. b and x satisfy-0.5.ltoreq.a.ltoreq.0.5, 0.ltoreq.b.ltoreq.0.1 and 0.ltoreq.x.ltoreq.0.5, respectively
For example, the lithium iron phosphate may be LiFePO 4 。
On the other hand, the positive electrode active material may include a carbon coating layer formed on the surface of the lithium iron phosphate. When the carbon coating layer is formed on the surface of the lithium iron phosphate, the conductivity is enhanced, so that the resistance characteristics of the positive electrode can be improved.
The carbon coating layer 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.
The thickness of the carbon coating may be 500nm or less, specifically 5nm to 400nm, more specifically 5nm to 300nm. When the thickness of the carbon coating layer satisfies the above range, the conductivity of the positive electrode active material can be improved, and an increase in resistance due to a decrease in lithium ion mobility caused by an excessively thick carbon coating layer can be prevented.
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. When the average particle diameter D of the lithium iron phosphate 50 When the above range is satisfied, lithium mobility in lithium iron phosphate is improved, so that charge/discharge characteristics of the battery can be improved.
The BET specific surface area of the positive electrode active material 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 a dispersant.
The content of the positive electrode active material may be 91.0 to 98.0 wt%, specifically 91.5 to 97.0 wt%, more specifically 92.0 to 97.0 wt%, based on the total solids content of the positive electrode slurry composition. When the content of the positive electrode active material satisfies the above range, the energy density per unit weight/volume of the positive electrode can be increased.
(2) Adhesive agent
The binder is used to aid in the bonding of the active materials, conductive materials, etc. to each other and to the current collector. The binder may include polyvinylidene fluoride (PVdF) satisfying the following mathematical formula 1.
[ mathematics 1]
0≤{(2A+B)/(C+D)}×100<0.2
In formula 1, A, B, C and D refer to PVdF 1 The integrated area of each peak in the H-NMR spectrum, A is the integrated area of the peak shown in the range of 11.5ppm to 12.8ppm,b is the integrated area of the peak shown in the range of 3.9ppm to 4.2ppm, C is the integrated area of the peak shown in the range of 2.6ppm to 3.2ppm, and D is the integrated area of the peak shown in the range of 2.1ppm to 2.35 ppm.
In this case, the interval of 11.5ppm to 12.8ppm means the functional group (COOH) contained in PVdF 1 The range of the H-NMR peak is 3.9ppm to 4.2ppm, which means the functional group (OCH) contained in PVdF 2 ) A kind of electronic device 1 H-NMR peak range. In addition, the interval of 2.6ppm to 3.2ppm refers to PVdF monomers bonded in a head-to-head (head-to-head) manner 1 The range of H-NMR peaks, the interval from 2.1ppm to 2.35ppm, refers to the head-to-tail (PVdF) monomers combined 1 H-NMR peak range.
On the other hand, PVdF satisfying the formula 1 means that, for example, COOH and OCH are contained in PVdF 2 The amount of polar functional groups is relatively small.
When PVdF contained in the binder in the positive electrode slurry composition does not satisfy equation 1, functional groups (e.g., COOH and OCH 2 ) And hydrogen in the carbon coating layer form many hydrogen bonds, whereby gelation of the positive electrode slurry composition may occur.
On the other hand, when PVdF contained in the binder in the positive electrode slurry composition satisfies equation 1, a small amount of functional groups are contained in the binder, so that the number of hydrogen bonds between the functional groups and hydrogen in the carbon coating layer decreases. Therefore, gelation of the positive electrode slurry composition can be prevented, coating workability of the positive electrode slurry composition can be enhanced, and the thickness and/or surface of the coated positive electrode active material layer can be uniformly formed.
In particular, when lithium iron phosphate is used as the positive electrode active material, the effect of preventing gelation of the positive electrode slurry composition is remarkable. In particular, since the average particle diameter of lithium iron phosphate is small and the specific surface area is large as compared with a conventional positive electrode active material such as lithium nickel cobalt manganese-based oxide, the area of sites where hydrogen bonding may occur is increased, and thus gelation is most likely to occur more severely. Therefore, when PVdF contained in the binder in the positive electrode slurry composition satisfies equation 1, the possibility of gelation in the positive electrode slurry composition using lithium iron phosphate as the positive electrode active material can be significantly reduced.
Preferably, when PVdF contained in the binder satisfies mathematical formula 1, the binder may be a homopolymer. For example, when the binder is a PVdF homopolymer, the polar functional groups described above are not present in the binder, and thus hydrogen bonds are not formed between the carbon coating and the binder. Therefore, gelation of the positive electrode slurry composition can be prevented.
The weight average molecular weight of the adhesive may be 20,000 to 1,200,000g/mol, specifically 100,000 to 1,000,000g/mol, more specifically 400,000 to 980,000g/mol. When the weight average molecular weight of the binder satisfies the above range, the positive electrode slurry composition can have a viscosity suitable for the coating process, and as a result, uniformity of the positive electrode active material layer formed from the composition can be ensured, and positive electrode adhesion can be improved.
The binder may be present in an amount of 1.8 to 4.0 wt%, specifically 1.8 to 3.8 wt%, more specifically 2.0 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, so that excellent positive electrode adhesion can be ensured.
(3) 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, which may be used alone or in combination of two or more thereof, may be used.
More specifically, the hydrogenated nitrile copolymer may be a hydrogenated nitrile 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.
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 can have a low viscosity and also have a high solid 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, so that 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 0.1 to 2.0 wt%, specifically 0.2 to 1.8 wt%, more specifically 0.4 to 1.6 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 positive electrode active material is suppressed, so that gelation of the positive electrode slurry composition can be prevented.
The content of the dispersant may be 40 parts by weight or more, specifically 45 parts by weight to 60 parts by weight, more specifically 50 parts by weight to 60 parts by weight, with respect to 100 parts by weight of the binder in the positive electrode slurry composition. When the content of the dispersant in the positive electrode slurry composition satisfies the above range, agglomeration of the positive electrode active material is suppressed, so that gelation of the positive electrode slurry composition can be prevented.
(4) Conductive material
On the other hand, the positive electrode slurry composition may further contain a conductive material, as needed, in addition to the positive electrode active material, the binder, the dispersant, and the solvent.
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, may be used: graphite; carbon 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; 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 the commercially available conductive material include acetylene black type products (bergamot chemical Company (Chevron Chemical Company)), danka black (singapore private Company (Denka Singapore Private Limited) of electric chemical industry Co.), products of Gulf Oil Company (Gulf Oil Company), ketjen black, EC type products (Armak Company), vulcan XC-72 (Cabot Company), super P (Timcal) Company, 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 invention 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 4.0 wt%, specifically 0.2 to 4.0 wt%, more specifically 0.6 to 3.5 wt%, based on the total solids content of the positive electrode slurry composition. When the above range is satisfied, the conductive network of the positive electrode is ensured, so that 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 65 wt%. When the solid content in the positive electrode slurry composition satisfies the above range, the composition has a viscosity at a coatable level, and the positive electrode active material layer formed of the composition has a thickness of a certain level or more, so that energy density can be ensured.
In the case of the positive electrode slurry composition according to one embodiment of the present invention, an inflection point may not occur in the rheological property map. For example, when the change in shear viscosity with the shear rate of the positive electrode slurry composition is measured using a rheometer, the shear rate on the graph is 10 -2.5 1/s to 10 0 There may be no inflection point in the range of 1/s. Thus, problems such as a change in composition with time, clogging of a filter during transfer of the composition, or gelation of the composition, which may occur when an inflection point appears on the graph, can be prevented.
Positive electrode
Next, a positive electrode according to the present invention 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. The positive electrode active material layer includes a positive electrode active material, a binder, and a dispersant, the positive electrode active material includes a lithium iron phosphate having a carbon coating layer on a surface thereof, and the binder includes polyvinylidene fluoride satisfying the following mathematical formula 1.
[ mathematics 1]
0≤{(2A+B)/(C+D)}×100<0.2
(A, B, C and D are obtained by polyvinylidene fluoride) 1 H-NMR measured at 11.5ppm to 12.8ppm, 3.9ppm to 4.2ppm,Integrated areas of the individual peaks shown at 2.6ppm to 3.2ppm and 2.1ppm to 2.35 ppm)
In addition, the positive electrode active material layer may further include a conductive material.
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.
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 material, 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 rolling.
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 invention 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 binder, and a dispersant, the positive electrode active material includes lithium iron phosphate having a carbon coating, and the binder includes polyvinylidene fluoride satisfying the following mathematical formula 1.
[ mathematics 1]
0≤{(2A+B)/(C+D)}×100<0.2
(A, B, C and D are obtained by polyvinylidene fluoride) 1 The integrated areas of the individual peaks shown at 11.5ppm to 12.8ppm, 3.9ppm to 4.2ppm, 2.6ppm to 3.2ppm and 2.1ppm to 2.35ppm as measured by H-NMR
In addition, the positive electrode may further include a conductive material.
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, high crystalline carbon, and the like; a (semi) metallic material capable of forming an alloy with lithium such as Si, al, sn, pb, zn, bi, in, mg, ga, cd, si alloy, sn alloy, al alloy, or the like; 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 materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, carbon fibers, carbon nanotubes, etc.; powders or fibers of metals 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%, specifically 1 to 20 wt%, more specifically 1 to 10 wt%, relative 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 the anode active material and an 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 rubber (EPDM rubber), 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%, specifically 1 to 20 wt%, more specifically 1 to 10 wt%, relative 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 the adhesiveness of 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 material, 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 of two or more layers thereof may be used. In addition, a conventional porous nonwoven fabric, such as 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 they are not particularly limited.
As the organic solvent, any solvent that can function as a medium through which ions participating in the electrochemical reaction of the battery can migrate may be used without particular limitation. Specifically, as the organic solvent, it is possible to use: ester solvents such as methyl acetate, ethyl acetate, gamma-butyrolactone, epsilon-caprolactone and 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), methyl ethyl carbonate (EMC), ethylene Carbonate (EC), propylene Carbonate (PC), etc.
Among the above-listed substances, carbonate solvents are preferable, and more preferable is a mixture of a cyclic carbonate compound (e.g., EC, PC, etc.) having high ion conductivity and high dielectric constant with a linear carbonate 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%.
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, and the like, the electrolyte may further contain, in addition to the above electrolyte components, one or more additives such as pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, (formal), hexamethylphosphoric triamide, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substitutedOxazolidinone, N-substituted imidazoline, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride, etc. 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 invention may be manufactured by inserting a separator between a positive electrode and a negative electrode to form an electrode assembly, placing the electrode assembly in a cylindrical battery case or a prismatic battery case, and injecting an electrolyte. Alternatively, the lithium secondary battery may be manufactured by stacking electrode assemblies, impregnating the electrode assemblies with an electrolyte, placing the resultant in a battery case, and sealing the battery case.
In the manufacture of the lithium secondary battery according to the present invention, 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, which are 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.
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 invention is useful in the following fields because it stably exhibits excellent discharge capacity, output characteristics, and capacity retention rate: portable devices such as mobile phones, laptop computers, digital cameras, etc.; an Energy Storage System (ESS); and electric vehicles such as Hybrid Electric Vehicles (HEVs).
Hereinafter, embodiments of the present invention will be described in further detail with reference to examples. However, the following examples are provided only for illustrating the present invention, and the scope of the present invention is not limited to the following examples.
Example 1: preparation of Positive electrode slurry composition
Average particle diameter D to be used as cathode active material 50 2 μm and a BET specific surface area of 11m 2 LiFePO/g and having a 200nm thick carbon coating on its surface 4 Carbon black as a conductive material, polyvinylidene fluoride (PVdF) as a homopolymer and having a weight average molecular weight of 630,000g/mol as a binder, and hydrogenated nitrile butadiene rubber (H-NBR) as a dispersant were added to the N-methylpyrrolidone solvent. Then, the positive electrode slurry composition was prepared by stirring at 2500rpm for 90 minutes using a stirrer (homogeneous disperser). The positive electrode slurry composition contains 93.6 parts of positive electrode active material, conductive material, binder and dispersing agent: 3.0:2.2:1.2, and the solid content of the positive electrode slurry composition was 59% by weight.
Example 2: preparation of Positive electrode slurry composition
Except at 93.3:2.5 weight ratio positive electrode active material and binder a positive electrode slurry composition was prepared in the same manner as in example 1.
Example 3: preparation of Positive electrode slurry composition
Except at 93.9:2.2: a positive electrode slurry composition was prepared in the same manner as in example 1, except that the positive electrode active material, the binder and the dispersant were mixed in a weight ratio of 0.9.
Comparative example 1: preparation of Positive electrode slurry composition
A positive electrode slurry composition was prepared in the same manner as in example 1, except that modified PVdF, which was a non-homopolymer and had a weight average molecular weight of 630,000g/mol, was used as a binder, and the solid content of the positive electrode slurry composition was 57 wt%.
TABLE 1
Experimental example 1 PVdF 1 H NMR measurement
Measurement of each PVdF used in examples 1 to 3 and comparative example 1 by Nuclear Magnetic Resonance (NMR) 1 H NMR, and determining whether PVdF satisfies the following equation 1.
Specifically, using NMR equipment (Bruker 600MHz available from Bruker corporation), at ns=1k, dl=3s, the temperature of the pulse sequences zg30, 298K, and DMSO-d 6 Measuring PVdF added to each of the compositions of examples 1 to 3 and comparative example 1 under the condition of the solvent 1 HNMR. The results are shown in fig. 1 and 2. In this case, FIG. 1 is a view of PVdF used in examples 1 to 3 1 FIG. 2 is an H NMR chart showing PVdF used in comparative example 1 1 H NMR chart. Referring to FIGS. 1 and 2, the integrated area (A) for the COOH-related peaks at 11.5ppm to 12.8ppm, the OCH-related peaks at 3.9ppm to 4.2ppm 2 The integrated area (B) of the relevant peaks, the integrated area (C) of the peaks related to head-to-head PVdF occurring at 2.6ppm to 3.2ppm, and the integrated area (D) of the peaks related to head-to-tail PVdF occurring at 2.1ppm to 2.35ppm were calculated, it was determined whether or not the A, B, C and D values satisfied the following equation 1, and the results thereof were shown in the following Table 2 as O or X (O: satisfied, X: not satisfied).
[ mathematics 1]
0≤{(2A+B)/(C+D)}×100<0.2
Experimental example 2 measurement of shear viscosity of Positive electrode slurry composition
The shear viscosity of the positive electrode slurry compositions prepared in examples 1 to 3 and comparative example 1 was measured using a rheometer (DHR 2 available from TA instruments), and the results thereof are graphically shown in fig. 3 below. Specifically, 10ml of the positive electrode slurry composition was put into a concentric cylinder type accessory of a rheometer at 25 ℃, and then its shear viscosity was measured, and the results thereof are graphically shown in fig. 3 below. Fig. 3 is a graph showing measurement results of the change in shear viscosity with the shear rate of each of the positive electrode slurry compositions prepared in examples 1 to 3 and comparative example 1.
In this case, 10 on the graph of FIG. 3 is determined -2.5 1/s to 10 0 Whether or not an inflection point appears in the shear rate range of 1/s, and the results thereof are shown in the following Table 2 as O or X (O: presence of inflection point, X: absence of inflection point). Here, the inflection point means a point where the shear viscosity increases or the shear viscosity hardly changes with an increase in the shear rate. In general, the positive electrode slurry composition exhibits a shear-thinning behavior in which the shear viscosity decreases with an increase in the shear rate, and when particle agglomeration is present in the positive electrode slurry composition, the positive electrode slurry composition can exhibit the following behavior: because of the interaction of the agglomerate particles, the shear viscosity increases or changes little as the shear rate increases on the shear viscosity map.
TABLE 2
Referring to table 2 and fig. 3, in the case of the positive electrode slurry composition of comparative example 1 in which PVdF contained in the binder does not satisfy mathematical formula 1, it can be confirmed that, unlike the positive electrode slurry compositions of examples 1 to 3, the composition was 10 on the shear viscosity chart -2 1/s to 10 -1 Inflection points appeared in the shear rate range of 1/s. In particular, it can be seen that the shear rate is in the range of 10 compared to other shear rate ranges -2 1/s to 10 -1 In the shear rate range of 1/s, the decrease in shear viscosity is very small relative to the increase in shear rate. From the results, it can be inferred that in the comparative example1, particle agglomeration occurs in the positive electrode slurry composition.
Claims (12)
1. A positive electrode slurry composition, the positive electrode slurry composition comprising: a positive electrode active material, a binder, a dispersant and a solvent,
wherein the positive electrode active material contains lithium iron phosphate having a carbon coating layer on the surface thereof, and
the adhesive comprises polyvinylidene fluoride satisfying the following formula 1,
[ mathematics 1]
0≤{(2A+B)/(C+D)}×100<0.2
Wherein A, B, C and D are those obtained by passing through said polyvinylidene fluoride 1 The integrated areas of the individual peaks shown at 11.5ppm to 12.8ppm, 3.9ppm to 4.2ppm, 2.6ppm to 3.2ppm and 2.1ppm to 2.35ppm as measured by H-NMR.
2. The positive electrode slurry composition according to claim 1, wherein the lithium iron phosphate is a compound represented by 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 average particle diameter D of the lithium iron phosphate 50 From 0.8 μm to 20.0. Mu.m.
4. The positive electrode slurry composition according to claim 1, wherein the content of the positive electrode active material is 91.0 to 98.0 wt% based on the total solid content of the positive electrode slurry composition.
5. The positive electrode slurry composition of claim 1, wherein the binder is a homopolymer.
6. The positive electrode slurry composition of claim 1, wherein the weight average molecular weight of the binder is 20,000g/mol to 1,200,000g/mol.
7. The positive electrode slurry composition according to claim 1, wherein the content of the binder is 1.8 to 4.0 wt% based on the total solid content of the positive electrode slurry composition.
8. The positive electrode slurry composition of claim 1, wherein the dispersant is a hydrogenated nitrile rubber.
9. The positive electrode slurry composition according to claim 1, wherein the content of the dispersant is 0.1 to 2.0 wt% based on the total solid content of the positive electrode slurry composition.
10. 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.
11. A positive electrode, the positive electrode comprising: a positive electrode collector and a positive electrode active material layer on at least one surface of the positive electrode collector,
wherein the positive electrode active material layer contains a positive electrode active material, a binder and a dispersant,
wherein the positive electrode active material contains lithium iron phosphate having a carbon coating layer on the surface thereof, and
wherein the adhesive comprises polyvinylidene fluoride satisfying the following formula 1,
[ mathematics 1]
0≤{(2A+B)/(C+D)}×100<0.2
Wherein A, B, C and D are those obtained by passing through said polyvinylidene fluoride 1 The integrated areas of the individual peaks shown at 11.5ppm to 12.8ppm, 3.9ppm to 4.2ppm, 2.6ppm to 3.2ppm and 2.1ppm to 2.35ppm as measured by H-NMR.
12. A lithium secondary battery, the lithium secondary battery comprising: a positive electrode, a negative electrode, a separator, and an electrolyte,
wherein the positive electrode comprises a positive electrode active material, a binder and a dispersing agent,
wherein the positive electrode active material contains lithium iron phosphate having a carbon coating layer on the surface thereof, and
wherein the adhesive comprises polyvinylidene fluoride satisfying the following formula 1,
[ mathematics 1]
0≤{(2A+B)/(C+D)}×100<0.2
Wherein A, B, C and D are those obtained by passing through said polyvinylidene fluoride 1 The integrated areas of the individual peaks shown at 11.5ppm to 12.8ppm, 3.9ppm to 4.2ppm, 2.6ppm to 3.2ppm and 2.1ppm to 2.35ppm as measured by H-NMR.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10-2021-0187191 | 2021-12-24 | ||
| KR10-2022-0178234 | 2022-12-19 | ||
| KR1020220178234A KR102652282B1 (en) | 2021-12-24 | 2022-12-19 | Positive electrode slurry composition, positive electrode and lithium secondary battery using the same |
| PCT/KR2022/020915 WO2023121275A1 (en) | 2021-12-24 | 2022-12-21 | Cathode slurry composition, cathode manufactured using same, and lithium secondary battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117280490A true CN117280490A (en) | 2023-12-22 |
Family
ID=89208539
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280033762.4A Pending CN117280490A (en) | 2021-12-24 | 2022-12-21 | Positive electrode slurry composition, positive electrode manufactured using same, and lithium secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117280490A (en) |
-
2022
- 2022-12-21 CN CN202280033762.4A patent/CN117280490A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108475772B (en) | Positive electrode for secondary battery and lithium secondary battery comprising same | |
| 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 | |
| CN107949940B (en) | Composition for forming positive electrode of secondary battery, positive electrode and secondary battery | |
| 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 | |
| KR102242254B1 (en) | Method for preparing positive electrode slurry for secondary battery | |
| US11283058B2 (en) | Method of preparing slurry composition for secondary battery positive electrode, positive electrode for secondary battery prepared by using the same, and lithium secondary battery including the positive electrode | |
| CN114930577A (en) | Negative electrode active material, and negative electrode and secondary battery comprising same | |
| CN114788043B (en) | Positive electrode for secondary battery, method for manufacturing same, and lithium secondary battery comprising same | |
| CN109863629B (en) | Method for preparing positive electrode slurry for lithium secondary battery and positive electrode for lithium secondary battery obtained thereby | |
| KR20230098028A (en) | Positive electrode slurry composition, positive electrode and lithium secondary battery using the same | |
| CN117501480A (en) | Method for manufacturing positive electrode current collector coated with adhesion-enhancing layer, positive electrode current collector coated with adhesion-enhancing layer manufactured thereby, method for manufacturing positive electrode for lithium secondary battery, positive electrode for lithium secondary battery manufactured thereby, and lithium secondary battery comprising same | |
| EP4322253A1 (en) | Cathode slurry composition, cathode manufactured using same, and lithium secondary battery | |
| KR102652282B1 (en) | Positive electrode slurry composition, positive electrode and lithium secondary battery using the same | |
| CN117280490A (en) | Positive electrode slurry composition, positive electrode manufactured using same, and lithium secondary battery | |
| US20230207807A1 (en) | Positive Electrode Slurry Composition and Lithium Secondary Battery Manufactured Using the Same | |
| CN113614949A (en) | Method of manufacturing negative electrode active material for secondary battery, negative electrode for secondary battery, and lithium secondary battery comprising same | |
| US20230207798A1 (en) | Positive Electrode Slurry Composition, Positive Electrode and Lithium Secondary Battery Manufactured Using the Same | |
| CN117203793A (en) | Positive electrode slurry composition, positive electrode manufactured using same, and lithium secondary battery | |
| CN116918094A (en) | Positive electrode slurry composition and lithium secondary battery manufactured using same | |
| EP4340075A1 (en) | Manufacturing method of positive electrode current collector coated with adhesion enhancement layer, positive electrode current collector coated with adhesion enhancement layer manufactured thereby, manufacturing method of positive electrode for lithium secondary battery, positive electrode for lithium secondary battery manufactured thereby, and lithium secondary battery comprising same | |
| US20240186521A1 (en) | Positive Electrode and Lithium Secondary Battery Manufactured Using the Same | |
| US20240154127A1 (en) | Positive Electrode and Lithium Secondary Battery Manufactured Using the Same | |
| KR20240058793A (en) | High-loading positive electrode, slurry for positive electrode and lithium secondary battery | |
| KR20240066114A (en) | Positive electrode, and lithium secondary battery using the same | |
| KR20230098037A (en) | Positive electrode slurry composition and lithium secondary battery using the same |
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 |