KR102584305B1 - Positive electrode and secondary battery comprsing the same - Google Patents
Positive electrode and secondary battery comprsing the same Download PDFInfo
- Publication number
- KR102584305B1 KR102584305B1 KR1020230090280A KR20230090280A KR102584305B1 KR 102584305 B1 KR102584305 B1 KR 102584305B1 KR 1020230090280 A KR1020230090280 A KR 1020230090280A KR 20230090280 A KR20230090280 A KR 20230090280A KR 102584305 B1 KR102584305 B1 KR 102584305B1
- Authority
- KR
- South Korea
- Prior art keywords
- active material
- positive electrode
- electrode active
- material layer
- iron phosphate
- Prior art date
Links
- 239000007774 positive electrode material Substances 0.000 claims abstract description 116
- 239000011149 active material Substances 0.000 claims abstract description 49
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 claims abstract description 49
- 239000011734 sodium Substances 0.000 claims abstract description 26
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims abstract description 14
- 229910052708 sodium Inorganic materials 0.000 claims abstract description 14
- VSZWPYCFIRKVQL-UHFFFAOYSA-N selanylidenegallium;selenium Chemical compound [Se].[Se]=[Ga].[Se]=[Ga] VSZWPYCFIRKVQL-UHFFFAOYSA-N 0.000 claims abstract description 9
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 21
- 229910052782 aluminium Inorganic materials 0.000 claims description 18
- 239000011230 binding agent Substances 0.000 claims description 15
- 239000007773 negative electrode material Substances 0.000 claims description 11
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 6
- 229960005196 titanium dioxide Drugs 0.000 claims description 6
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 6
- 239000000701 coagulant Substances 0.000 claims description 4
- YULBFWISFJEMQB-UHFFFAOYSA-N oxotin titanium Chemical compound [Sn]=O.[Ti] YULBFWISFJEMQB-UHFFFAOYSA-N 0.000 claims description 3
- 229920002401 polyacrylamide Polymers 0.000 claims description 3
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 3
- 229920002635 polyurethane Polymers 0.000 claims description 3
- 239000004814 polyurethane Substances 0.000 claims description 3
- 239000010410 layer Substances 0.000 description 58
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 45
- 239000002245 particle Substances 0.000 description 35
- 238000004519 manufacturing process Methods 0.000 description 25
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 20
- 229910052744 lithium Inorganic materials 0.000 description 19
- 239000002904 solvent Substances 0.000 description 19
- -1 Lithium transition metal Chemical class 0.000 description 18
- 239000002033 PVDF binder Substances 0.000 description 18
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 18
- 239000006245 Carbon black Super-P Substances 0.000 description 17
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 16
- 238000002156 mixing Methods 0.000 description 16
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 15
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 14
- 239000007864 aqueous solution Substances 0.000 description 14
- 229910052799 carbon Inorganic materials 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 14
- 239000000243 solution Substances 0.000 description 14
- 239000011247 coating layer Substances 0.000 description 13
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- 239000000203 mixture Substances 0.000 description 9
- 239000011267 electrode slurry Substances 0.000 description 8
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 7
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 7
- 235000011114 ammonium hydroxide Nutrition 0.000 description 7
- 239000003963 antioxidant agent Substances 0.000 description 7
- 238000010924 continuous production Methods 0.000 description 7
- 229910000358 iron sulfate Inorganic materials 0.000 description 7
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 7
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 description 6
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 6
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 6
- 239000006256 anode slurry Substances 0.000 description 6
- 239000004020 conductor Substances 0.000 description 6
- 239000008151 electrolyte solution Substances 0.000 description 6
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 6
- 229920000573 polyethylene Polymers 0.000 description 6
- 239000002562 thickening agent Substances 0.000 description 6
- 239000004698 Polyethylene Substances 0.000 description 5
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 5
- 229910052759 nickel Inorganic materials 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 229910052726 zirconium Inorganic materials 0.000 description 5
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 4
- 229910013870 LiPF 6 Inorganic materials 0.000 description 4
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 4
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 4
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- 239000003575 carbonaceous material Substances 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- 229920001577 copolymer Polymers 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910044991 metal oxide Inorganic materials 0.000 description 4
- 150000004706 metal oxides Chemical class 0.000 description 4
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 4
- 239000010935 stainless steel Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 229910052719 titanium Inorganic materials 0.000 description 4
- 239000010936 titanium Substances 0.000 description 4
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 3
- 239000005977 Ethylene Substances 0.000 description 3
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 229920001971 elastomer Polymers 0.000 description 3
- 229910052731 fluorine Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910021382 natural graphite Inorganic materials 0.000 description 3
- 239000004745 nonwoven fabric Substances 0.000 description 3
- 239000005060 rubber Substances 0.000 description 3
- DHKHKXVYLBGOIT-UHFFFAOYSA-N 1,1-Diethoxyethane Chemical compound CCOC(C)OCC DHKHKXVYLBGOIT-UHFFFAOYSA-N 0.000 description 2
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 description 2
- 229910018626 Al(OH) Inorganic materials 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- 229920002943 EPDM rubber Polymers 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 239000006230 acetylene black Substances 0.000 description 2
- 229910021383 artificial graphite Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 description 2
- 239000004917 carbon fiber Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- VUPKGFBOKBGHFZ-UHFFFAOYSA-N dipropyl carbonate Chemical compound CCCOC(=O)OCCC VUPKGFBOKBGHFZ-UHFFFAOYSA-N 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000011737 fluorine Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910052738 indium Inorganic materials 0.000 description 2
- 229910000398 iron phosphate Inorganic materials 0.000 description 2
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910001416 lithium ion Inorganic materials 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- KKQAVHGECIBFRQ-UHFFFAOYSA-N methyl propyl carbonate Chemical compound CCCOC(=O)OC KKQAVHGECIBFRQ-UHFFFAOYSA-N 0.000 description 2
- 229910052758 niobium Inorganic materials 0.000 description 2
- 239000010955 niobium Substances 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 229920006254 polymer film Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 235000010344 sodium nitrate Nutrition 0.000 description 2
- 239000004317 sodium nitrate Substances 0.000 description 2
- 229920003048 styrene butadiene rubber Polymers 0.000 description 2
- MBNVSWHUJDDZRH-UHFFFAOYSA-N 2-methylthiirane Chemical compound CC1CS1 MBNVSWHUJDDZRH-UHFFFAOYSA-N 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229910016569 AlF 3 Inorganic materials 0.000 description 1
- 229910017119 AlPO Inorganic materials 0.000 description 1
- 229910000925 Cd alloy Inorganic materials 0.000 description 1
- 229910052684 Cerium Inorganic materials 0.000 description 1
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 1
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- 229920002153 Hydroxypropyl cellulose Polymers 0.000 description 1
- 229910010710 LiFePO Inorganic materials 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-M Methacrylate Chemical compound CC(=C)C([O-])=O CERQOIWHTDAKMF-UHFFFAOYSA-M 0.000 description 1
- 229920000265 Polyparaphenylene Polymers 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 229910000676 Si alloy Inorganic materials 0.000 description 1
- 229910001128 Sn alloy Inorganic materials 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- QXZUUHYBWMWJHK-UHFFFAOYSA-N [Co].[Ni] Chemical compound [Co].[Ni] QXZUUHYBWMWJHK-UHFFFAOYSA-N 0.000 description 1
- KLARSDUHONHPRF-UHFFFAOYSA-N [Li].[Mn] Chemical compound [Li].[Mn] KLARSDUHONHPRF-UHFFFAOYSA-N 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 229910003481 amorphous carbon Inorganic materials 0.000 description 1
- 125000003710 aryl alkyl group Chemical group 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- IAQRGUVFOMOMEM-UHFFFAOYSA-N butene Natural products CC=CC IAQRGUVFOMOMEM-UHFFFAOYSA-N 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000012461 cellulose resin Substances 0.000 description 1
- 239000011294 coal tar pitch Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 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
- 238000004891 communication Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 150000002334 glycols Chemical class 0.000 description 1
- 239000011357 graphitized carbon fiber Substances 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 239000001863 hydroxypropyl cellulose Substances 0.000 description 1
- 235000010977 hydroxypropyl cellulose Nutrition 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000007561 laser diffraction method Methods 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- RSNHXDVSISOZOB-UHFFFAOYSA-N lithium nickel Chemical compound [Li].[Ni] RSNHXDVSISOZOB-UHFFFAOYSA-N 0.000 description 1
- 229910003002 lithium salt Inorganic materials 0.000 description 1
- 159000000002 lithium salts Chemical class 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000002931 mesocarbon microbead Substances 0.000 description 1
- 239000011302 mesophase pitch Substances 0.000 description 1
- 239000002905 metal composite material Substances 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 239000011255 nonaqueous electrolyte Substances 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000011301 petroleum pitch Substances 0.000 description 1
- 239000011295 pitch Substances 0.000 description 1
- 229920001515 polyalkylene glycol Polymers 0.000 description 1
- 229920001228 polyisocyanate Polymers 0.000 description 1
- 239000005056 polyisocyanate Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 235000019422 polyvinyl alcohol Nutrition 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
- 239000011148 porous material Substances 0.000 description 1
- 239000002296 pyrolytic carbon Substances 0.000 description 1
- 239000004627 regenerated cellulose Substances 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- HXJUTPCZVOIRIF-UHFFFAOYSA-N sulfolane Chemical compound O=S1(=O)CCCC1 HXJUTPCZVOIRIF-UHFFFAOYSA-N 0.000 description 1
- 229920005608 sulfonated EPDM Polymers 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/364—Composites as mixtures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/621—Binders
- H01M4/622—Binders being polymers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/028—Positive electrodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
본 발명은 집전체, 상기 집전체의 일면에 형성된 제1 양극 활물질층, 및 상기 집전체의 타면에 형성된 제2 양극 활물질층을 포함하며, 상기 제1 양극 활물질층은 지르코늄(zr) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하고, 상기 제2 양극 활물질층은 나트륨(Na) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하는 양극 및 이를 포함하는 이차 전지를 제공한다.The present invention includes a current collector, a first positive electrode active material layer formed on one side of the current collector, and a second positive electrode active material layer formed on the other side of the current collector, wherein the first positive electrode active material layer is doped with a zirconium (zr) element. Provided is a positive electrode including a lithium iron phosphate-based active material, and the second positive electrode active material layer includes a lithium iron phosphate-based active material doped with a sodium (Na) element, and a secondary battery including the same.
Description
본 발명은 양극 및 이를 포함하는 이차 전지에 관한 것이다.The present invention relates to a positive electrode and a secondary battery including the same.
전자, 통신 및 우주 산업이 발전됨에 따라, 에너지 동력원으로서 이차전지(secondary battery)의 수요가 급격히 증대되고 있다. 특히, 글로벌 친환경 정책의 중요성이 강조됨에 따라 전기 자동차 시장이 비약적으로 성장 중이며, 국내외에서 이차전지에 관한 연구 개발이 활발히 이루어지고 있다.As the electronics, communications, and space industries develop, the demand for secondary batteries as an energy power source is rapidly increasing. In particular, as the importance of global eco-friendly policies is emphasized, the electric vehicle market is growing rapidly, and research and development on secondary batteries is being actively conducted at home and abroad.
다양한 이차전지 중에서도 높은 방전 전압 및 에너지 밀도를 가진 리튬 이차전지는 각종 모바일 기기 및 다양한 전자제품의 에너지원으로 널리 사용되고 있다. Among various secondary batteries, lithium secondary batteries with high discharge voltage and energy density are widely used as an energy source for various mobile devices and various electronic products.
리튬 이차전지의 양극 활물질로는 리튬 전이금속 복합 산화물이 이용되고 있으며, 이중에서도 작용전압이 높고 용량 특성이 우수한 LiCoO2의 리튬코발트 복합금속 산화물이 주로 사용되고 있다. 그러나, LiCoO2는 안정성이 낮고 고가이기 때문에, 리튬 이차전지를 대량 생산하기 어려운 문제점이 있다.Lithium transition metal composite oxide is used as a positive electrode active material for lithium secondary batteries, and among these, lithium cobalt composite metal oxide of LiCoO 2 , which has a high operating voltage and excellent capacity characteristics, is mainly used. However, because LiCoO 2 has low stability and is expensive, it is difficult to mass-produce lithium secondary batteries.
이에 LiCoO2를 대체하기 위한 재료로서, 리튬망간 복합금속 산화물, 리튬철 인산화물, 리튬니켈 복합금속 산화물 등이 개발되었다. 이중에서 올리빈 구조를 갖는 리튬철 인산화물(LiFePO4)은 3.6g/cm3의 높은 체적 밀도를 가지며 이론 용량은 약 170mAh/g을 나타낸다. Accordingly, as materials to replace LiCoO 2 , lithium manganese composite metal oxide, lithium iron phosphate, and lithium nickel composite metal oxide were developed. Among these, lithium iron phosphate (LiFePO 4 ) with an olivine structure has a high volume density of 3.6 g/cm 3 and a theoretical capacity of about 170 mAh/g.
다만, 리튬철 인산화물(LiFePO4)은 낮은 전기 전도성으로 인해, LiFePO4를 양극 활물질로서 사용하는 경우 전지의 내부 저항이 증가되며, 이로 인해 방전 용량 및 수명 특성이 저하되는 문제가 발생하였다. However, due to the low electrical conductivity of lithium iron phosphate (LiFePO 4 ), when LiFePO 4 is used as a positive electrode active material, the internal resistance of the battery increases, which causes the problem of deterioration of discharge capacity and lifespan characteristics.
특히, 최근에는 하이브리드 자동차나 전기 자동차의 구동용 전원으로서, 리튬 이차전지를 적용하고 있는 바, 리튬 이차전지의 향상된 방전 용량 및 우수한 수명 특성을 가지는 것이 요구되고 있다.In particular, in recent years, lithium secondary batteries have been used as a power source for driving hybrid vehicles and electric vehicles, and there is a demand for lithium secondary batteries to have improved discharge capacity and excellent lifespan characteristics.
본 발명은 방전 용량 및 수명 특성이 향상되며, 전압 강화가 최소화된 양극 및 이를 포함하는 이차 전지를 제공한다.The present invention provides a positive electrode with improved discharge capacity and lifespan characteristics and minimal voltage enhancement, and a secondary battery including the same.
본 발명에 따른 양극은 집전체, 상기 집전체의 일면에 형성된 제1 양극 활물질층, 및 상기 집전체의 타면에 형성된 제2 양극 활물질층을 포함하며, 상기 제1 양극 활물질층은 지르코늄(zr) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하고, 상기 제2 양극 활물질층은 나트륨(Na) 원소가 도핑된 리튬철 인산화물계 활물질을 포함한다.The positive electrode according to the present invention includes a current collector, a first positive electrode active material layer formed on one side of the current collector, and a second positive electrode active material layer formed on the other side of the current collector, wherein the first positive electrode active material layer is made of zirconium (zr). It includes a lithium iron phosphate-based active material doped with an element, and the second positive electrode active material layer includes a lithium iron phosphate-based active material doped with a sodium (Na) element.
본 발명의 일 실시예에 있어서, 상기 제1 양극 활물질층은 상기 리튬철 인산화물계 활물질 상에 코팅된 알루미늄(Al) 원소를 포함할 수 있다.In one embodiment of the present invention, the first positive electrode active material layer may include aluminum (Al) element coated on the lithium iron phosphate-based active material.
본 발명의 일 실시예에 있어서, 상기 제1 양극 활물질층 및 상기 제2 양극 활물질층 각각은 폴리아크릴아마이드(Polyacrylamide), 폴리우레탄(polyurethane), 및 폴리아크릴로나이트릴(polyacrylonitrile)로 이루어진 군에서 선택되는 1종 이상의 수평균 분자량 30,000 g/mol 내지 80,000 g/mol를 가지는 바인더 응집제를 포함할 수 있다.In one embodiment of the present invention, each of the first positive electrode active material layer and the second positive electrode active material layer is selected from the group consisting of polyacrylamide, polyurethane, and polyacrylonitrile. It may include one or more selected binder coagulants having a number average molecular weight of 30,000 g/mol to 80,000 g/mol.
본 발명에 따른 이차 전지는 양극, 음극, 상기 양극 및 음극 사이에 개재된 분리막을 포함하며, 상기 양극은 집전체, 상기 집전체의 일면에 형성된 제1 양극 활물질층, 및 상기 집전체의 타면에 형성된 제2 양극 활물질층을 포함하며, 상기 제1 양극 활물질층은 지르코늄(zr) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하고, 상기 제2 양극 활물질층은 나트륨(Na) 원소가 도핑된 리튬철 인산화물계 활물질을 포함한다.A secondary battery according to the present invention includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode includes a current collector, a first positive electrode active material layer formed on one side of the current collector, and a second positive electrode active material layer formed on the other side of the current collector. It includes a formed second positive electrode active material layer, wherein the first positive electrode active material layer includes a lithium iron phosphate-based active material doped with a zirconium (zr) element, and the second positive electrode active material layer includes a lithium doped with a sodium (Na) element. Contains iron phosphate-based active materials.
본 발명의 일 실시예에 있어서, 상기 음극은 니오비움(niobium)이 도핑된 티타늄-틴-옥사이드(titanium-tin-oxide) 및 상기 니오비움이 도핑된 티타늄-옥사이드(titanium-oxide)중 적어도 하나를 포함할 수 있다.In one embodiment of the present invention, the cathode is at least one of niobium-doped titanium-tin-oxide and niobium-doped titanium-oxide. may include.
본 발명에 따른 양극은 집전체의 일면 및 타면에 서로 다른 원소가 도핑된 리튬철 인산화물계 활물질을 포함함으로써, 방전 용량 및 수명 특성이 향상되며, 전압 강화 현상이 최소화될 수 있다.The positive electrode according to the present invention includes a lithium iron phosphate-based active material doped with different elements on one side and the other side of the current collector, so that discharge capacity and lifespan characteristics can be improved, and voltage enhancement phenomenon can be minimized.
본 명세서 또는 출원에 개시되어 있는 실시예들에 대한 구조적 또는 기능적 설명들은 단지 본 발명의 기술적 사상에 따른 실시예들을 설명하기 위한 목적으로 예시된 것으로, 본 발명의 기술적 사상에 따른 실시예들은 본 명세서 또는 출원에 개시되어 있는 실시예들 이외에도 다양한 형태로 실시될 수 있으며, 본 발명의 기술적 사상이 본 명세서 또는 출원에 설명된 실시예들에 한정되는 것으로 해석되지 않는다.The structural or functional descriptions of the embodiments disclosed in the present specification or application are merely illustrative for the purpose of explaining embodiments according to the technical idea of the present invention, and the embodiments according to the technical idea of the present invention are described in this specification. Alternatively, it may be implemented in various forms other than the embodiments disclosed in the application, and the technical idea of the present invention is not to be construed as being limited to the embodiments described in this specification or application.
이하에서, 본 발명에 따른 양극 및 이차 전지에 대하여 설명한다.Below, the positive electrode and secondary battery according to the present invention will be described.
<양극><Anode>
본 발명에 따른 양극은 집전체, 상기 집전체의 일면에 형성된 제1 양극 활물질층, 및 상기 집전체의 타면에 형성된 제2 양극 활물질층을 포함하며, 상기 제1 양극 활물질층은 지르코늄(Zr) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하고, 상기 제2 양극 활물질층은 나트륨(Na) 원소가 도핑된 리튬철 인산화물계 활물질을 포함한다.The positive electrode according to the present invention includes a current collector, a first positive electrode active material layer formed on one side of the current collector, and a second positive electrode active material layer formed on the other side of the current collector, wherein the first positive electrode active material layer is made of zirconium (Zr). It includes a lithium iron phosphate-based active material doped with an element, and the second positive electrode active material layer includes a lithium iron phosphate-based active material doped with a sodium (Na) element.
본 발명에 따른 양극은 집전체를 포함한다. 상기 집전체는 이차 전지에 화학적 변화를 유발하지 않으면서 높은 도전성을 가지는 것이라면 특별히 제한되지 않으며, 예를 들어 스테인레스 스틸, 알루미늄, 니켈, 티탄, 소성 탄소, 또는 알루미늄이나 스테리인레스 스틸의 표면에 카본, 니켈, 티탄, 은 등으로 표면처리한 것 등을 사용할 수 있다. 상기 양극 집전체의 두께는 요구되는 제품에 따라 조절될 수 있고, 예를 들어 10㎛ 내지 500㎛, 10㎛ 내지 300㎛, 또는 20㎛ 내지 300㎛일 수 있다.The positive electrode according to the present invention includes a current collector. The current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the secondary battery, for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or carbon on the surface of aluminum or stainless steel. , those surface treated with nickel, titanium, silver, etc. can be used. The thickness of the positive electrode current collector may be adjusted depending on the required product, and may be, for example, 10 μm to 500 μm, 10 μm to 300 μm, or 20 μm to 300 μm.
본 발명에 따른 양극은 상기 집전체 상에 형성되며 회합성 우레탄계 증점제 및 바인더를 포함하는 코팅층을 포함할 수 있다.The positive electrode according to the present invention is formed on the current collector and may include a coating layer containing an associative urethane-based thickener and a binder.
상기 코팅층은 상기 집전체와 상기 제1 양극 활물질층 사이, 또는 상기 집전체와 상기 제2 양극 활물질층 사이에서의 계면 접착력을 향상시킬 수 있다. 상기 코팅층은 전극 표면에 핀홀이 발생되는 것을 억제하기 위해 회합성 우레탄계 증점제를 포함할 수 있다. 상기 회합성 우레탄계 증점제는 양극 활물질 간 응집력을 강화시킬 수 있다.The coating layer may improve interfacial adhesion between the current collector and the first positive electrode active material layer, or between the current collector and the second positive electrode active material layer. The coating layer may include an associative urethane-based thickener to prevent pinholes from forming on the electrode surface. The associative urethane-based thickener can enhance cohesion between positive electrode active materials.
상기 회합성 우레탄 증점제는 폴리알킬렌 글리콜 화합물로서, 예를 들어, 폴리이소시아네이트 및 소수성 말단기로 이루어진 알킬, 아릴 또는 아릴알킬 유형의 회합성으로 지칭되는 단량체 또는 축합물 사이의 합성으로 생성된 공중합체로 지칭될 수 있다.The associative urethane thickeners are polyalkylene glycol compounds, for example copolymers produced by synthesis between polyisocyanates and monomers or condensates, referred to as associative, of the alkyl, aryl or arylalkyl type consisting of hydrophobic end groups. It may be referred to as .
상기 회합성 우레탄계 증점제의 중량평균 분자량은 200,000 g/mol 내지 500,000 g/mol, 250,000 g/mol 내지 500,000 g/mol, 250,000 g/mol 내지 450,000 g/mol, 300,000 g/mol 내지 450,000 g/mol, 350,000 g/mol 내지 450,000 g/mol, 또는 350,000 g/mol 내지 400,000 g/mol일 수 있다.The weight average molecular weight of the associative urethane-based thickener is 200,000 g/mol to 500,000 g/mol, 250,000 g/mol to 500,000 g/mol, 250,000 g/mol to 450,000 g/mol, 300,000 g/mol to 450,000 g/mol, It may be 350,000 g/mol to 450,000 g/mol, or 350,000 g/mol to 400,000 g/mol.
상기 코팅층은 코팅층 조성물로부터 제조될 수 있고, 상기 코팅층 조성물 전체 중량 대비, 상기 회합성 우레탄계 증점제는 0.01 중량% 내지 3.00 중량%, 0.01 중량% 내지 1.00 중량%, 또는 0.1 중량% 내지 1.00 중량%로 포함될 수 있다.The coating layer may be manufactured from a coating layer composition, and the associative urethane-based thickener may be included in an amount of 0.01 wt% to 3.00 wt%, 0.01 wt% to 1.00 wt%, or 0.1 wt% to 1.00 wt%, based on the total weight of the coating layer composition. You can.
상기 코팅층은 바인더를 포함할 수 있다. 상기 바인더는 스티렌 부타디엔 고무(SBR)를 포함할 수 있다. 상기 바인더는 폴리불화비닐리덴, 폴리비닐알코올, 전분, 히드록시프로필셀룰로우즈, 재생 셀룰로우즈, 폴리비닐피롤리돈, 테트라플루오로에틸렌, 폴리에틸렌, 폴리프로필렌, 에틸렌-프로필렌-디엔 테르 폴리머(EPDM), 술폰화 EPDM, 스티렌 브티렌 고무, 불소 고무, 스티렌(styrene monomer: SM), 부타디엔 (butadiene: BD) 및 부틸 아크릴레이트(butyl acrylate: BA)로 이루어진 군에서 선택되는 하나 이상을 더 포함할 수 있다.The coating layer may include a binder. The binder may include styrene butadiene rubber (SBR). The binder is polyvinylidene fluoride, polyvinyl alcohol, starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer ( EPDM), sulfonated EPDM, styrene butyrene rubber, fluorine rubber, styrene (styrene monomer: SM), butadiene (BD), and butyl acrylate (BA). can do.
본 발명에 따른 양극은 상기 집전체의 일면에 형성된 제1 양극 활물질층, 및 상기 집전체의 타면에 형성된 제2 양극 활물질층을 포함하며, 상기 제1 양극 활물질층은 지르코늄(Zr) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하고, 상기 제2 양극 활물질층은 나트륨(Na) 원소가 도핑된 리튬철 인산화물계 활물질을 포함한다.The positive electrode according to the present invention includes a first positive electrode active material layer formed on one side of the current collector, and a second positive electrode active material layer formed on the other side of the current collector, wherein the first positive electrode active material layer is doped with a zirconium (Zr) element. and a lithium iron phosphate-based active material, and the second positive electrode active material layer includes a lithium iron phosphate-based active material doped with a sodium (Na) element.
상기 리튬철 인산화물계 활물질은 하기 화학식 1로 표시되는 화합물일 수 있다. The lithium iron phosphate-based active material may be a compound represented by the following formula (1).
[화학식 1][Formula 1]
Li1+aFe1-xMx(PO4-b)Yb Li 1+a Fe 1-x M x (PO 4-b )Y b
상기 화학식 1에서, M은 Ni, Co, Mn, Ti, Ga, Cu, V, Nb, Zr, Ce, In 및 Cu로 이루어진 군에서 선택되는 어느 하나 이상의 원소이며, Y는 F, S 및 N로 이루어진 군에서 선택되는 어느 하나 이상의 원소이고, a, b, x는 -0.5≤a≤0.5, 0≤b≤0.1, 0≤x≤0.5이다.In Formula 1, M is one or more elements selected from the group consisting of Ni, Co, Mn, Ti, Ga, Cu, V, Nb, Zr, Ce, In, and Cu, and Y is represented by F, S, and N. It is one or more elements selected from the group consisting of, and a, b, and x are -0.5≤a≤0.5, 0≤b≤0.1, 0≤x≤0.5.
상기 리튬철 인산화물계 활물질은 LiFePO4일 수 있다.The lithium iron phosphate-based active material may be LiFePO 4 .
일반적으로, 리튬철 인산화물계 활물질은 니켈 코발트계 금속 산화물 활물질 대비 안정성이 우수하다. 다만, 리튬철 인산화물계 활물질은 낮은 전기 전도성으로 인해 양극 활물질로 사용하는 경우 이차 전지의 내부 저항이 증가되는 문제가 있다. 또한, 용량이 작고, 장기간 사용 시 사이클 특성이 급격히 저하되고, 열적 안정성이 저하되는 문제가 있다. In general, lithium iron phosphate-based active materials have superior stability compared to nickel cobalt-based metal oxide active materials. However, lithium iron phosphate-based active materials have a problem in that the internal resistance of the secondary battery increases when used as a positive electrode active material due to low electrical conductivity. In addition, the capacity is small, and when used for a long period of time, there is a problem of rapid deterioration in cycle characteristics and deterioration of thermal stability.
이에, 본 발명에 따른 양극 활물질층은 상기 집전체의 일면 및 타면에 지르코늄(Zr) 원소가 도핑된 리튬철 인산화물계 활물질과 나트륨(Na) 원소가 도핑된 리튬철 인산화물계 활물질을 각각 포함한다. 상기 지르코늄과 나트륨 도핑 물질에 의해 상기 제1 양극 활물질층과 상기 제2 양극 활물질층은 각기 다른 SOC 구간에서 전압 강하 구간이 발생되어, 전압 강하 시점에서의 저항 증가폭이 개선될 수 있고, 결과적으로 이차 전지의 성능이 향상될 수 있다.Accordingly, the positive electrode active material layer according to the present invention includes a lithium iron phosphate-based active material doped with a zirconium (Zr) element and a lithium iron phosphate-based active material doped with a sodium (Na) element on one side and the other side of the current collector, respectively. Due to the zirconium and sodium doping materials, the first positive electrode active material layer and the second positive electrode active material layer generate a voltage drop section in different SOC sections, so that the amount of resistance increase at the point of the voltage drop can be improved, and as a result, the secondary Battery performance can be improved.
상기 리튬철 인산화물계 활물질에 도핑된 상기 지르코늄은 양극 활물질의 기계적 특성을 향상시켜, 이차 전지의 제조 공정 또는 외부 충격에 의해 양극 활물질이 깨지는 현상이 최소화될 수 있다.The zirconium doped into the lithium iron phosphate-based active material improves the mechanical properties of the positive electrode active material, thereby minimizing the phenomenon of the positive electrode active material being broken due to the manufacturing process of a secondary battery or external impact.
상기 제1 양극 활물질층 전체 중량 대비, 상기 지르코늄의 함량은 500 ppm 내지 9,000 ppm, 500 ppm 내지 8,000 ppm, 500 ppm 내지 7,000 ppm, 500 ppm 내지 6,000 ppm, 500 ppm 내지 5,000 ppm, 또는 500 ppm 내지 3,000 ppm으로 포함될 수 있다. 상기 범위를 만족하는 경우, 이차 전지의 기계적 특성 및 전기 전도도가 향상될 수 있어, 이차 전지의 장기 사용시 스웰링 현상이 저감될 수 있고, 수명 특성이 향상될 수 있다.Compared to the total weight of the first positive electrode active material layer, the zirconium content is 500 ppm to 9,000 ppm, 500 ppm to 8,000 ppm, 500 ppm to 7,000 ppm, 500 ppm to 6,000 ppm, 500 ppm to 5,000 ppm, or 500 ppm to 3,000 ppm. Can be included in ppm. When the above range is satisfied, the mechanical properties and electrical conductivity of the secondary battery can be improved, the swelling phenomenon can be reduced during long-term use of the secondary battery, and the lifespan characteristics can be improved.
상기 제1 양극 활물질층은 상기 리튬철 인산화물계 활물질 상에 코팅된 알루미늄(Al) 원소를 포함할 수 있다. 상기 알루미늄 원소가 상기 리튬철 인산화물계 활물질 상에 형성됨으로써, 상기 리튬철 인산화물계 활물질 표면의 화학적 안정성이 향상되어, 상기 리튬철 인산화물계 활물질의 구조적 붕괴가 억제될 수 있다.The first positive electrode active material layer may include aluminum (Al) element coated on the lithium iron phosphate-based active material. By forming the aluminum element on the lithium iron phosphate-based active material, the chemical stability of the surface of the lithium iron phosphate-based active material is improved, and structural collapse of the lithium iron phosphate-based active material can be suppressed.
또한, 리튬철 인산화물계 활물질에 포함된 금속 대비 상기 알루미늄 원소가 먼저 산화되어, 상기 리튬철 인산화물계 활물질과 전해액과의 부반응이 억제될 수 있어, 리튬 이온의 이동에 따른 저항 상승이 방지될 수 있다.In addition, the aluminum element is oxidized first compared to the metal contained in the lithium iron phosphate-based active material, so side reactions between the lithium iron phosphate-based active material and the electrolyte can be suppressed, and an increase in resistance due to the movement of lithium ions can be prevented. .
상기 코팅층에 상기 알루미늄 원소가 형성되기 위한 전구체로서 Al2O3, Al(OH)3, AlF3, AlBr3, AlPO4, AlCl3, Al(NO)3, Al(H2PO4)3, 및 C2H5O4Al으로 이루어진 군에서 선택된 1종 이상이 사용될 수 있다.As a precursor for forming the aluminum element in the coating layer, Al 2 O 3 , Al(OH) 3 , AlF 3 , AlBr 3 , AlPO 4 , AlCl 3 , Al(NO) 3 , Al(H 2 PO 4 ) 3 , And one or more species selected from the group consisting of C 2 H 5 O 4 Al may be used.
상기 리튬철 인산화물계 활물질에 도핑된 상기 나트륨은 상기 리튬철 인산화물계 활물질 표면의 화학적 안정성을 향상시켜, 상기 리튬철 인산화물계 활물질의 구조적 붕괴가 억제될 수 있다.The sodium doped into the lithium iron phosphate-based active material improves the chemical stability of the surface of the lithium iron phosphate-based active material, and structural collapse of the lithium iron phosphate-based active material can be suppressed.
상기 제2 양극 활물질층 전체 중량 대비, 상기 나트륨 원소의 함량은 500 ppm 내지 5,000 ppm, 500 ppm 내지 4,000 ppm, 500 ppm 내지 3,500 ppm, 500 ppm 내지 3,000 ppm, 600 ppm 내지 3,000 ppm, 700 ppm 내지 3,000 ppm, 800 ppm 내지 3,000 ppm, 또는 800 ppm 내지 2,000 ppm으로 포함될 수 있다. 상기 범위를 만족하는 경우, 과도한 코팅층 형성에 의한 이차 전지의 저항이 증가되거나 출력이 감소하는 현상이 억제될 수 있다.Compared to the total weight of the second positive electrode active material layer, the content of the sodium element is 500 ppm to 5,000 ppm, 500 ppm to 4,000 ppm, 500 ppm to 3,500 ppm, 500 ppm to 3,000 ppm, 600 ppm to 3,000 ppm, and 700 ppm to 3,000. ppm, 800 ppm to 3,000 ppm, or 800 ppm to 2,000 ppm. When the above range is satisfied, the phenomenon of increased resistance or decreased output of the secondary battery due to excessive formation of a coating layer can be suppressed.
상기 나트륨 원소가 형성되기 위한 전구체로서 NaOH, Ba(OH)2, Na2CO3, NaCl, CH3COONa, Na2SO4, 및 NaNO2으로 이루어진 군에서 선택된 1종 이상이 사용될 수 있다.As a precursor for forming the sodium element, one or more species selected from the group consisting of NaOH, Ba(OH) 2 , Na 2 CO 3 , NaCl, CH 3 COONa, Na 2 SO 4 , and NaNO 2 may be used.
상기 제1 양극 활물질층, 상기 제2 양극 활물질층, 또는 상기 제1,2 양극 활물질층은 상기 리튬철 인산화물계 활물질 내에 질소(N) 원소가 도핑된 구조를 포함할 수 있다. 상기 질소 원소는 이차 전지의 전기 전도도를 향상시켜, 이차 전지의 초기 효율이 저하되는 현상이 최소화될 수 있다.The first positive electrode active material layer, the second positive active material layer, or the first and second positive active material layers may include a structure in which the lithium iron phosphate-based active material is doped with a nitrogen (N) element. The nitrogen element improves the electrical conductivity of the secondary battery, thereby minimizing the decrease in initial efficiency of the secondary battery.
상기 제1,2 양극 활물질층 전체 중량 대비, 상기 질소 원소의 함량은 300 ppm 내지 10,000 ppm, 500 ppm 내지 5,000 ppm, 500 ppm 내지 4,000 ppm, 500 ppm 내지 3,000 ppm, 500 ppm 내지 2,000 ppm, 또는 500 ppm 내지 1,500 ppm으로 포함될 수 있다. 상기 범위를 만족하는 경우, 이차 전지의 전기 전도도가 향상되며, 초기 효율이 저하되는 현상이 최소화될 수 있다.Compared to the total weight of the first and second positive electrode active material layers, the content of the nitrogen element is 300 ppm to 10,000 ppm, 500 ppm to 5,000 ppm, 500 ppm to 4,000 ppm, 500 ppm to 3,000 ppm, 500 ppm to 2,000 ppm, or 500 ppm. It may be included in amounts ranging from ppm to 1,500 ppm. When the above range is satisfied, the electrical conductivity of the secondary battery is improved, and the phenomenon of initial efficiency reduction can be minimized.
상기 제1 양극 활물질층에 포함된 리튬철 인산화물계 활물질 및 상기 제2 양극 활물질층에 포함된 리튬철 인산화물계 활물질은 전도성 코팅층을 포함할 수 있다. The lithium iron phosphate-based active material included in the first positive electrode active material layer and the lithium iron phosphate-based active material included in the second positive electrode active material layer may include a conductive coating layer.
상기 전도성 코팅층은 탄소계 물질을 포함할 수 있다. 상기 탄소계 물질은 카본 블랙, 탄소 섬유 또는 금속 섬유, 금속 분말, 도전성 위스커, 도전성 금속, 활성 카본(activated carbon) 폴리페닐렌 유도체, 천연 흑연, 인조 흑연, 슈퍼 피(Super-P), 아세틸렌 블랙, 케첸 블랙, 채널 블랙, 피네이스 블랙, 램프 블랙, 서머 블랙, 덴카 블랙, 알루미늄 분말, 니켈 분말, 산화아연, 티탄산 갈륨 및 산화 티탄으로 이루어진 군으로부터 선택된 1종 이상이 사용될 수 있다. The conductive coating layer may include a carbon-based material. The carbon-based material includes carbon black, carbon fiber or metal fiber, metal powder, conductive whisker, conductive metal, activated carbon, polyphenylene derivative, natural graphite, artificial graphite, Super-P, and acetylene black. , Ketjen Black, Channel Black, Phineas Black, Lamp Black, Summer Black, Denka Black, aluminum powder, nickel powder, zinc oxide, gallium titanate, and titanium oxide may be used.
상기 전도성 코팅층의 두께는 1 nm 내지 500 nm, 1 nm 내지 300 nm, 1 nm 내지 250 nm, 1 nm 내지 200 nm, 5 nm 내지 200 nm, 5 nm 내지 100 nm, 또는 5 nm 내지 50 nm일 수 있다. 상기 범위를 만족하는 경우, 리튬 이온의 이동에 장애가 되지 않으며, 전기 전도도가 상승될 수 있다.The thickness of the conductive coating layer may be 1 nm to 500 nm, 1 nm to 300 nm, 1 nm to 250 nm, 1 nm to 200 nm, 5 nm to 200 nm, 5 nm to 100 nm, or 5 nm to 50 nm. there is. When the above range is satisfied, there is no obstacle to the movement of lithium ions, and electrical conductivity can be increased.
상기 전도성 코팅층에 포함된 탄소의 함량은 상기 제1,2 양극 활물질층 총 중량 기준 1 중량% 내지 3 중량%, 1 중량% 내지 2.5 중량%, 1 중량% 내지 2 중량%일 수 있다. 상기 범위를 만족하는 경우, 전기 전도도 저하에 따른 저항 증가 문제를 야기하지 않으며, 양극 제조 시 양극 활물질이 탈리되는 현상을 최소화할 수 있다.The content of carbon included in the conductive coating layer may be 1% to 3% by weight, 1% to 2.5% by weight, or 1% to 2% by weight based on the total weight of the first and second positive electrode active material layers. When the above range is satisfied, there is no problem of increased resistance due to a decrease in electrical conductivity, and the phenomenon of detachment of the positive electrode active material during production of the positive electrode can be minimized.
상기 제1 양극 활물질층 및 상기 제2 양극 활물질층에 포함된 리튬철 인산화물계 활물질의 평균 입경(D50)은 0.3㎛ 내지 10.0㎛, 0.3㎛ 내지 9.0㎛, 또는 0.6㎛ 내지 9.0㎛일 수 있다. 평균 입경(D50)은 양극 활물질 입경 분포의 50% 기준에서의 입경으로 정의할 수 있다. 또한, 평균 입경(D50)은 레이저 회절법(laser diffraction method)을 이용하여 측정할 수 있다. 상기 범위를 만족하는 경우, 도전재 및 바인더와 균일한 혼합이 가능하며, 공정 효율성이 증가될 수 있다.The average particle diameter (D 50 ) of the lithium iron phosphate-based active material included in the first positive electrode active material layer and the second positive electrode active material layer may be 0.3 μm to 10.0 μm, 0.3 μm to 9.0 μm, or 0.6 μm to 9.0 μm. . The average particle diameter (D 50 ) can be defined as the particle size based on 50% of the particle size distribution of the positive electrode active material. Additionally, the average particle diameter (D 50 ) can be measured using a laser diffraction method. When the above range is satisfied, uniform mixing with the conductive material and binder is possible, and process efficiency can be increased.
상기 제1 양극 활물질층 및 상기 제2 양극 활물질층에 포함된 리튬철 인산화물계 활물질의 비표면적(BET)은 30m2/g 이하, 20m2/g 이하, 또는 5m2/g 내지 15m2/g일 수 있다. 비표면적(BET)은 BEL Japan사의 BELSORP-mino II를 이용하여 액체 질소 온도 하(77K)에서의 질소가스 흡착량으로부터 산출할 수 있다. 상기 범위를 만족하는 경우, 양극 집전체와의 접착력 저하를 야기하지 않을 수 있다.The specific surface area (BET) of the lithium iron phosphate-based active material included in the first positive electrode active material layer and the second positive electrode active material layer is 30 m 2 /g or less, 20 m 2 /g or less, or 5 m 2 /g to 15 m 2 /g. It can be. Specific surface area (BET) can be calculated from the amount of nitrogen gas adsorption under liquid nitrogen temperature (77K) using BELSORP-mino II from BEL Japan. When the above range is satisfied, adhesion to the positive electrode current collector may not be reduced.
상기 제1 양극 활물질층 및 상기 제2 양극 활물질층에 포함된 리튬철 인산화물계 활물질의 탭 밀도(tap density)는 0.5g/cm3 이상, 0.6g/cm3 이상, 또는 0.6g/cm3 내지 1.5g/cm3일 수 있다. 탭밀도는 상기 리튬철 인산화물계 활물질 분말의 겉보기 밀도를 의미하며, Seishin 社의 KYT-5000를 이용하여 측정할 수 있다. 상기 범위를 만족하는 경우, 양극의 충진밀도가 향상되어, 양극의 두께가 얇게 개선되며, 양극 활물질의 깨짐 현상을 개선할 수 있다.The tap density of the lithium iron phosphate-based active material contained in the first positive electrode active material layer and the second positive electrode active material layer is 0.5 g/cm 3 or more, 0.6 g/cm 3 or more, or 0.6 g/cm 3 or more. It may be 1.5g/cm 3 . Tap density refers to the apparent density of the lithium iron phosphate-based active material powder, and can be measured using Seishin's KYT-5000. When the above range is satisfied, the packing density of the positive electrode is improved, the thickness of the positive electrode can be improved to be thinner, and the cracking phenomenon of the positive electrode active material can be improved.
상기 제1 양극 활물질층 및 상기 제2 양극 활물질층 각각은 도전재 및 바인더를 포함할 수 있다. 상기 바인더는 상기 리튬철 인산화물계 활물질 및 도전재 간의 결합력과 제1,2 양극 활물질층 및 양극 집전체 간의 결합력을 향상시킬 수 있다. 상기 바인더는 상기 리튬철 인산화물계 활물질 100 중량부 기준 1 내지 30 중량부, 1 내지 20 중량부, 또는 1 내지 15 중량부로 첨가될 수 있다. 상기 바인더의 종류는 특별히 제한되지 않으나, 예를 들어 폴리비닐리덴플로라이드(PVDF), 폴리테트라플루오로에틸렌(PTFE), 불소 고무, 스티렌 부타디엔 고무(SBR, 셀룰로오스계 수지 등이 사용될 수 있다.Each of the first positive electrode active material layer and the second positive electrode active material layer may include a conductive material and a binder. The binder can improve the bonding force between the lithium iron phosphate-based active material and the conductive material and the bonding force between the first and second positive electrode active material layers and the positive electrode current collector. The binder may be added in an amount of 1 to 30 parts by weight, 1 to 20 parts by weight, or 1 to 15 parts by weight based on 100 parts by weight of the lithium iron phosphate-based active material. The type of the binder is not particularly limited, but for example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), fluorine rubber, styrene butadiene rubber (SBR), cellulose resin, etc. can be used.
상기 도전재는 상기 리튬철 인산화물계 활물질의 도전성을 향상시킬 수 있다. 상기 도전재는 상기 리튬철 인산화물계 활물질 100 중량부 기준 1 내지 40 중량부, 1 내지 20 중량부, 또는 1 내지 10 중량부로 첨가될 수 있다. 상기 도전재의 종류는 특별히 제한되지 않으나, 예를 들어 슈퍼-비(Super-P), 흑연, 아세틸렌 블랙 등이 사용될 수 있다. The conductive material can improve the conductivity of the lithium iron phosphate-based active material. The conductive material may be added in an amount of 1 to 40 parts by weight, 1 to 20 parts by weight, or 1 to 10 parts by weight based on 100 parts by weight of the lithium iron phosphate-based active material. The type of the conductive material is not particularly limited, but for example, Super-P, graphite, acetylene black, etc. may be used.
상기 제1 양극 활물질층 및 상기 제2 양극 활물질층 각각은 폴리아크릴아마이드(Polyacrylamide), 폴리우레탄(polyurethane), 및 폴리아크릴로나이트릴(polyacrylonitrile)로 이루어진 군에서 선택되는 1종 이상의 수평균 분자량 30,000 g/mol 내지 80,000 g/mol를 가지는 바인더 응집제를 포함할 수 있다. 상기 바인더 응집제는 상기 바인더의 분산성을 적절히 조절하여, 상기 집전체 상에 상기 바인더가 집중적으로 분포되어 전기 전도도가 저하되는 현상이 억제될 수 있다.Each of the first positive electrode active material layer and the second positive electrode active material layer has a number average molecular weight of at least 30,000 selected from the group consisting of polyacrylamide, polyurethane, and polyacrylonitrile. It may include a binder coagulant having g/mol to 80,000 g/mol. The binder coagulant can appropriately control the dispersibility of the binder, thereby suppressing a phenomenon in which the binder is intensively distributed on the current collector, thereby reducing electrical conductivity.
<이차 전지><Secondary battery>
본 발명에 따른 이차 전지는 양극, 음극, 상기 양극 및 음극 사이에 개재된 분리막을 포함하며, 상기 양극은 집전체, 상기 집전체의 일면에 형성된 제1 양극 활물질층, 및 상기 집전체의 타면에 형성된 제2 양극 활물질층을 포함하며, 상기 제1 양극 활물질층은 지르코늄(zr) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하고, 상기 제2 양극 활물질층은 나트륨(Na) 원소가 도핑된 리튬철 인산화물계 활물질을 포함한다. A secondary battery according to the present invention includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode includes a current collector, a first positive electrode active material layer formed on one side of the current collector, and a second positive electrode active material layer formed on the other side of the current collector. It includes a formed second positive electrode active material layer, wherein the first positive electrode active material layer includes a lithium iron phosphate-based active material doped with a zirconium (zr) element, and the second positive electrode active material layer includes a lithium doped with a sodium (Na) element. Contains iron phosphate-based active materials.
상기 양극은 전술한 양극과 관련하여 기재된 집전체, 제1,2 양극 활물질층 등과 동일하게 사용할 수 있다.The positive electrode can be used in the same manner as the current collector, first and second positive electrode active material layers, etc. described in relation to the positive electrode described above.
상기 이차 전지는 본 발명의 양극 외에, 음극 및 분리막을 포함할 수 있다. 상기 음극은 음극 집전체 및 음극 집전체 상에 형성된 음극 활물질층을 포함할 수 있다. The secondary battery may include a negative electrode and a separator in addition to the positive electrode of the present invention. The negative electrode may include a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector.
상기 음극 집전체는 당해 이차 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 구리, 스테인레스 스틸, 알루미늄, 니켈, 티탄, 소성 탄소, 구리나 스테인레스 스틸의 표면에 카본, 니켈, 티탄, 은 등으로 표면처리한 것, 알루미늄-카드뮴 합금 등이 사용될 수 있다. 또한, 표면에 미세한 요철을 형성하여 음극 활물질의 결합력을 강화시킬 수도 있으며, 필름, 시트, 호일, 네트, 다공질체, 발포체, 부직포체 등 다양한 형태로 사용될 수 있다.The negative electrode current collector is not particularly limited as long as it has conductivity without causing chemical changes in the secondary battery, for example, copper, stainless steel, aluminum, nickel, titanium, fired carbon, the surface of copper or stainless steel. Surface treatment with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can be used. In addition, the bonding power of the negative electrode active material can be strengthened by forming fine irregularities on the surface, and it can be used in various forms such as films, sheets, foils, nets, porous materials, foams, and non-woven fabrics.
상기 음극 활물질층은 음극 활물질을 포함할 수 있다. The negative electrode active material layer may include a negative electrode active material.
상기 음극 활물질은 인조흑연, 천연흑연, 흑연화 탄소섬유, 비정질탄소, 고결정성 탄소 등의 탄소질 재료; Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si합금, Sn합금 또는 Al합금 등 리튬과 합금화가 가능한 금속질 화합물을 사용할 수 있다. 저결정성 탄소로는 연화탄소(soft carbon) 및 경화탄소(hard carbon)를 들 수 있으며, 고결정성 탄소로는 천연 흑연, 키시흑연(kish graphite), 열분해 탄소(pyrolytic carbon), 액정치피계 탄소섬유(mesophase pitch based carbon fiber), 탄소 미소구체(meso-carbon microbeads), 액정피치(mesophase pitches) 및 석유와 석탄계 코크스(petroleum or coal tar pitch derived cokes) 등의 고온 소성탄소를 들 수 있다. 음극 활물질은 필요에 따라 금속질 화합물과 탄소질 재료를 포함하는 복합물 등을 사용할 수도 있다. The negative electrode active material may include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fiber, amorphous carbon, and highly crystalline carbon; Metallic compounds that can be alloyed with lithium, such as Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloy, Sn alloy, or Al alloy, can be used. Low-crystalline carbon includes soft carbon and hard carbon, and high-crystalline carbon includes natural graphite, kish graphite, pyrolytic carbon, and liquid crystalline carbon. Examples include high-temperature calcined carbon such as mesophase pitch based carbon fiber, meso-carbon microbeads, mesophase pitches, and petroleum or coal tar pitch derived cokes. The negative electrode active material may be a composite containing a metallic compound and a carbonaceous material, if necessary.
바람직하게는, 상기 음극 활물질은 리튬 덴트라이드 발생을 억제하고, 상기 이차 전지의 수명 특성을 향상시키기 위해, 상기 음극 활물질은 니오비움(niobium)이 도핑된 티타늄-틴-옥사이드(titanium-tin-oxide) 및 상기 니오비움이 도핑된 티타늄-옥사이드(titanium-oxide)중 적어도 하나를 포함할 수 있다. Preferably, in order to suppress the generation of lithium dentride and improve the lifespan characteristics of the secondary battery, the negative electrode active material is titanium-tin-oxide doped with niobium. ) and the niobium-doped titanium-oxide (titanium-oxide).
상기 분리막은 음극 및 양극 사이에 개재될 수 있다. 상기 분리막은 음극과 양극 간 전기적 단락을 방지하고, 이온의 흐름이 발생되도록 구성된다. 상기 분리막은 다공성 고분자 필름 또는 다공성 부직포를 포함할 수 있다. 상기 다공성 고분자 필름은 에틸렌(ethylene) 중합체, 프로필렌(propylene) 중합체, 에틸렌/부텐(ethylene/butene) 공중합체, 에틸렌/헥센(ethylene/hexene) 공중합체, 및 에틸렌/메타크릴레이트(ethylene/methacrylate) 공중합체 등과 같은 폴리올레핀계 고분자를 포함한 단일층 혹은 다중층으로 구성될 수 있다. 상기 다공성 부직포는 고융점의 유리 섬유, 폴리에틸렌테레프탈레이트(polyethylene terephthalate) 섬유를 포함할 수 있다. 다만, 이에 한정되는 것이 아니며, 실시 형태에 따라 분리막은 세라믹(ceramic)을 포함한 고내열성 분리막(CCS; Ceramic Coated Separator)일 수 있다. The separator may be interposed between the cathode and the anode. The separator is configured to prevent electrical short-circuiting between the cathode and the anode and to generate a flow of ions. The separator may include a porous polymer film or a porous non-woven fabric. The porous polymer film includes ethylene polymer, propylene polymer, ethylene/butene copolymer, ethylene/hexene copolymer, and ethylene/methacrylate. It may be composed of a single layer or multiple layers containing polyolefin-based polymers such as copolymers. The porous nonwoven fabric may include high melting point glass fibers and polyethylene terephthalate (polyethylene terephthalate) fibers. However, it is not limited to this, and depending on the embodiment, the separator may be a highly heat-resistant separator (CCS; Ceramic Coated Separator) containing ceramic.
상기 양극, 음극 및 분리막은 권취(winding), 적층(lamination), 접음(folding), 또는 지그재그 스태킹(Zigzag stacking) 공정에 의해 전극 조립체로 제조될 수 있다. 상기 전극 조립체는 전해액과 함께 제공되어 본 발명에 따른 이차 전지로 제조될 수 있다. 상기 이차 전지는 캔을 사용한 원통형, 각형, 파우치(pouch)형, 및 코인(coin)형 중 어느 하나일 수 있으나, 이에 한정되는 것은 아니다.The anode, cathode, and separator may be manufactured into an electrode assembly by a winding, lamination, folding, or zigzag stacking process. The electrode assembly is provided with an electrolyte solution and can be manufactured into a secondary battery according to the present invention. The secondary battery may be any one of a cylindrical, square, pouch, or coin type using a can, but is not limited thereto.
상기 전해액은 비수 전해액일 수 있다. 전해액은 리튬염과 유기 용매를 포함할 수 있다. 상기 유기 용매는 프로필렌 카보네이트(PC), 에틸렌 카보네이트(EC), 디에틸 카보네이트(DEC), 디메틸 카보네이트(DMC), 에틸메틸 카보네이트(EMC), 메틸프로필 카보네이트(MPC), 디프로필 카보네이트(DPC), 비닐렌 카보네이트(VC), 디메틸 설포사이드(dimethyl sulfoxide), 아세토니트릴(acetonitrile), 디메톡시에탄(dimethoxyethane), 디에톡시에탄(diethoxyethane), 설포란(sulfolane), 감마-부티로락톤(gamma-butyrolactone), 프로필렌 설파이드(propylene sulfide), 또는 테트라하이드로퓨란(tetrahydrofuran) 중 적어도 어느 하나를 포함할 수 있다.The electrolyte may be a non-aqueous electrolyte. The electrolyte solution may include a lithium salt and an organic solvent. The organic solvent includes propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), methylpropyl carbonate (MPC), dipropyl carbonate (DPC), Vinylene carbonate (VC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, sulfolane, gamma-butyrolactone ), propylene sulfide, or tetrahydrofuran.
이하에서, 실시예 및 비교예를 바탕으로 본 발명을 더욱 구체적으로 설명한다. 다만, 다음의 실시예 및 비교예는 본 발명을 더욱 상세히 설명하기 위한 예시일 뿐, 본 발명이 다음의 실시예 및 비교예에 의해 한정되는 것은 아니다.Below, the present invention will be described in more detail based on examples and comparative examples. However, the following examples and comparative examples are only examples to explain the present invention in more detail, and the present invention is not limited by the following examples and comparative examples.
실시예Example
실시예 1Example 1
<제1 양극 활물질 제조><Manufacture of first positive electrode active material>
황산철(FeSO4ㆍ7H2O), 인산(H3PO4), 지르코니아(ZrO2) 및 산화 방지제를 포함한 수용액과 리튬 수용액(LiOHㆍH2O)의 혼합물에 pH 6이 되도록 암모니아수를 첨가하여 양극 슬러리를 제조하였다. 이후, 연속 공정 초임계 반응기에서 400 ℃ 및 270 bar의 조건하에 상기 양극 슬러리를 일정 속도로 투입하여 LiFePO4 용액을 제조하였으며, 상기 LiFePO4 용액을 수세 및 여과하여 Zr이 도핑된 LiFePO4 입자를 수득하였다. Add ammonia water to pH 6 to a mixture of an aqueous solution containing iron sulfate (FeSO 4 ㆍ7H 2 O), phosphoric acid (H 3 PO 4 ), zirconia (ZrO 2 ) and antioxidants, and lithium aqueous solution (LiOHㆍH 2 O). A positive electrode slurry was prepared. Afterwards, a LiFePO 4 solution was prepared by adding the anode slurry at a constant rate under the conditions of 400° C. and 270 bar in a continuous process supercritical reactor, and the LiFePO 4 solution was washed and filtered to obtain Zr-doped LiFePO 4 particles. did.
상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제1 양극 활물질을 제조하였다.The first positive electrode active material was prepared by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5.
<제2 양극 활물질 제조><Manufacture of second positive electrode active material>
황산철(FeSO4ㆍ7H2O), 인산(H3PO4), 질산나트륨(NaNo3) 및 산화 방지제를 포함한 수용액과 리튬 수용액(LiOHㆍH2O)의 혼합물에 pH 6이 되도록 암모니아수를 첨가하여 양극 슬러리를 제조하였다. 이후, 연속 공정 초임계 반응기에서 400 ℃ 및 270 bar의 조건하에 상기 양극 슬러리를 일정 속도로 투입하여 LiFePO4 용액을 제조하였으며, 상기 LiFePO4 용액을 수세 및 여과하여 Na이 도핑된 LiFePO4 입자를 수득하였다. Add ammonia water to pH 6 in a mixture of an aqueous solution containing iron sulfate (FeSO 4 ㆍ7H 2 O), phosphoric acid (H 3 PO 4 ), sodium nitrate (NaNo 3 ) and antioxidants, and lithium aqueous solution (LiOH ㆍH 2 O). was added to prepare a positive electrode slurry. Afterwards, a LiFePO 4 solution was prepared by adding the anode slurry at a constant rate under the conditions of 400° C. and 270 bar in a continuous process supercritical reactor, and the LiFePO 4 solution was washed and filtered to obtain Na-doped LiFePO 4 particles. did.
상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제2 양극 활물질을 제조하였다.The second positive electrode active material was prepared by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5.
<양극 제조><Anode manufacturing>
15 ㎛ 두께의 알루미늄(Al)의 일면에 상기 제1 양극 활물질을 도포하였으며, 상기 알루미늄의 타면에는 상기 제2 양극 활물질을 도포한 후 건조하였다. 이후, 건조가 완료된 상기 제1 양극 활물질 및 상기 제2 양극 활물질을 압연하여 상기 알루미늄 상에 제1 양극 활물질층 및 제2 양극 활물질층이 형성된 양극을 제조하였다. The first positive electrode active material was applied to one side of aluminum (Al) with a thickness of 15 μm, and the second positive electrode active material was applied to the other side of the aluminum and then dried. Thereafter, the dried first and second positive electrode active materials were rolled to manufacture a positive electrode in which a first and second positive electrode active material layers were formed on the aluminum.
<이차 전지 제조><Secondary battery manufacturing>
음극 활물질로서 TiNb2O7(TNO)을 포함하는 음극 및 상기 제조된 양극 사이에 두께 25 ㎛의 폴리에틸렌 소재의 분리막을 개재하여 전극 조립체를 제조한 후, 상기 전극 조립체를 케이스에 수납하고, 케이스 내부에 에틸렌 카보네이트:메틸에틸카보네이트가 2:1의 부피비로 혼합된 용매에 LiPF6 1M 및 비닐카보네이트 2.5 중량%로 혼합된 전해액을 투입하여 이차 전지를 제조하였다. After manufacturing an electrode assembly by interposing a separator made of polyethylene with a thickness of 25 ㎛ between a negative electrode containing TiNb 2 O 7 (TNO) as a negative electrode active material and the manufactured positive electrode, the electrode assembly is stored in a case, and the inside of the case is A secondary battery was manufactured by adding an electrolyte solution containing 1M LiPF 6 and 2.5% by weight of vinyl carbonate to a solvent containing ethylene carbonate:methylethylcarbonate mixed at a volume ratio of 2:1.
실시예 2 Example 2
상기 실시예 1에서 상기 Zr이 도핑된 LiFePO4 입자 및 상기 Na이 도핑된 LiFePO4 입자 각각에 대해, 코팅 물질로서 Al(OH)3을 혼합한 후, 700 ℃ 에서 5시간 동안 열처리하여 Al이 코팅된 입자를 각각 수득하였다. In Example 1, for each of the Zr-doped LiFePO 4 particles and the Na-doped LiFePO 4 particles, Al(OH) 3 was mixed as a coating material, and then Al was coated by heat treatment at 700° C. for 5 hours. Each particle was obtained.
상기 실시예 1에서, 상기 Zr이 도핑된 LiFePO4 입자 대신 상기 Al이 코팅되며 Zr이 도핑된 LiFePO4 입자를 사용하며, 상기 Na이 도핑된 LiFePO4 입자 대신 상기 Al이 코팅되며 Na이 도핑된 LiFePO4 입자를 사용하는 것을 제외하고는, 상기 실시예 1과 동일한 공정에 의해 이차 전지를 제조하였다.In Example 1, the Al-coated and Zr-doped LiFePO 4 particles are used instead of the Zr-doped LiFePO 4 particles, and the Al-coated and Na-doped LiFePO 4 particles are used instead of the Na-doped LiFePO 4 particles. A secondary battery was manufactured through the same process as Example 1 above, except for using 4 particles.
실시예 3 Example 3
상기 실시예 1에서 상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제1 양극 활물질을 제조하는 대신, 상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 96:2:2의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제1 양극 활물질을 제조하는 것을 제외하고는, 상기 실시예 1과 동일한 공정에 의해 이차 전지를 제조하였다.In Example 1, instead of preparing the first positive electrode active material by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in an N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5, the LiFePO The same method as Example 1 above, except that the first positive electrode active material was prepared by mixing 4 particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 96:2:2. A secondary battery was manufactured through the process.
실시예 4Example 4
상기 실시예 2에서 상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제1 양극 활물질을 제조하는 대신, 상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 96:2:2의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제1 양극 활물질을 제조하는 것을 제외하고는, 상기 실시예 2와 동일한 공정에 의해 이차 전지를 제조하였다.In Example 2, instead of preparing the first positive electrode active material by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in an N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5, the LiFePO 4 Same as Example 2, except that the first positive electrode active material was prepared by mixing particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 96:2:2. A secondary battery was manufactured through the process.
실시예 5Example 5
상기 실시예 1에서 상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제2 양극 활물질을 제조하는 대신, 상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 96:2:2의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제2 양극 활물질을 제조하는 것을 제외하고는, 상기 실시예 1과 동일한 공정에 의해 이차 전지를 제조하였다.In Example 1, instead of preparing the second positive electrode active material by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in an N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5, the LiFePO 4 The same method as Example 1, except that the second positive electrode active material was prepared by mixing particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 96:2:2. A secondary battery was manufactured through the process.
실시예 6Example 6
상기 실시예 2에서 상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제2 양극 활물질을 제조하는 대신, 상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 96:2:2의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제2 양극 활물질을 제조하는 것을 제외하고는, 상기 실시예 2와 동일한 공정에 의해 이차 전지를 제조하였다.In Example 2, instead of preparing the second positive electrode active material by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in an N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5, the LiFePO 4 Same as Example 2, except that the second positive electrode active material was prepared by mixing particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 96:2:2. A secondary battery was manufactured through the process.
비교예 1Comparative Example 1
<양극 활물질 제조><Manufacture of positive electrode active material>
황산철(FeSO4ㆍ7H2O), 인산(H3PO4), 및 산화 방지제를 포함한 수용액과 리튬 수용액(LiOHㆍH2O)의 혼합물에 pH 6이 되도록 암모니아수를 첨가하여 양극 슬러리를 제조하였다. 이후, 연속 공정 초임계 반응기에서 400 ℃ 및 270 bar의 조건하에 상기 양극 슬러리를 일정 속도로 투입하여 LiFePO4 용액을 제조하였으며, 상기 LiFePO4 용액을 수세 및 여과하여 LiFePO4 입자를 수득하였다. Prepare a positive electrode slurry by adding aqueous ammonia to a mixture of an aqueous solution containing iron sulfate (FeSO 4 ㆍ7H 2 O), phosphoric acid (H 3 PO 4 ), and antioxidants, and lithium aqueous solution (LiOHㆍH 2 O) to pH 6. did. Afterwards, a LiFePO 4 solution was prepared by adding the anode slurry at a constant rate under the conditions of 400 ° C. and 270 bar in a continuous process supercritical reactor, and the LiFePO 4 solution was washed and filtered to obtain LiFePO 4 particles .
상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 양극 활물질을 제조하였다.A positive electrode active material was prepared by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5.
<양극 제조><Anode manufacturing>
15 ㎛ 두께의 알루미늄(Al)의 양면에 상기 양극 활물질을 도포한 후 건조하였다. 이후, 건조가 완료된 상기 양극 활물질을 압연하여 상기 알루미늄 상에 양극 활물질층이 형성된 양극을 제조하였다.The positive electrode active material was applied to both sides of aluminum (Al) with a thickness of 15 ㎛ and then dried. Afterwards, the dried positive electrode active material was rolled to manufacture a positive electrode in which a positive electrode active material layer was formed on the aluminum.
<이차 전지 제조><Secondary battery manufacturing>
탄소계 음극 및 상기 제조된 양극 사이에 두께 25 ㎛의 폴리에틸렌 소재의 분리막을 개재하여 전극 조립체를 제조한 후, 상기 전극 조립체를 케이스에 수납하고, 케이스 내부에 에틸렌 카보네이트:메틸에틸카보네이트가 2:1의 부피비로 혼합된 용매에 LiPF6 1M 및 비닐카보네이트 2.5 중량%로 혼합된 전해액을 투입하여 이차 전지를 제조하였다. After manufacturing an electrode assembly by interposing a separator made of polyethylene with a thickness of 25 ㎛ between the carbon-based cathode and the manufactured anode, the electrode assembly is stored in a case, and ethylene carbonate:methylethyl carbonate is mixed in a ratio of 2:1 inside the case. A secondary battery was manufactured by adding an electrolyte solution containing 1M LiPF 6 and 2.5% by weight of vinyl carbonate to a solvent mixed at a volume ratio of .
비교예 2Comparative Example 2
<제1 양극 활물질 제조><Manufacture of first positive electrode active material>
황산철(FeSO4ㆍ7H2O), 인산(H3PO4), 지르코니아(ZrO2) 및 산화 방지제를 포함한 수용액과 리튬 수용액(LiOHㆍH2O)의 혼합물에 pH 6이 되도록 암모니아수를 첨가하여 양극 슬러리를 제조하였다. 이후, 연속 공정 초임계 반응기에서 400 ℃ 및 270 bar의 조건하에 상기 양극 슬러리를 일정 속도로 투입하여 LiFePO4 용액을 제조하였으며, 상기 LiFePO4 용액을 수세 및 여과하여 Zr이 도핑된 LiFePO4 입자를 수득하였다. Add ammonia water to pH 6 to a mixture of an aqueous solution containing iron sulfate (FeSO 4 ㆍ7H 2 O), phosphoric acid (H 3 PO 4 ), zirconia (ZrO 2 ) and antioxidants, and lithium aqueous solution (LiOHㆍH 2 O). A positive electrode slurry was prepared. Afterwards, a LiFePO 4 solution was prepared by adding the anode slurry at a constant rate under the conditions of 400° C. and 270 bar in a continuous process supercritical reactor, and the LiFePO 4 solution was washed and filtered to obtain Zr-doped LiFePO 4 particles. did.
상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제1 양극 활물질을 제조하였다.The first positive electrode active material was prepared by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5.
<제2 양극 활물질 제조><Manufacture of second positive electrode active material>
황산철(FeSO4ㆍ7H2O), 인산(H3PO4), 및 산화 방지제를 포함한 수용액과 리튬 수용액(LiOHㆍH2O)의 혼합물에 pH 6이 되도록 암모니아수를 첨가하여 양극 슬러리를 제조하였다. 이후, 연속 공정 초임계 반응기에서 400 ℃ 및 270 bar의 조건하에 상기 양극 슬러리를 일정 속도로 투입하여 LiFePO4 용액을 제조하였으며, 상기 LiFePO4 용액을 수세 및 여과하여 LiFePO4 입자를 수득하였다. Prepare a positive electrode slurry by adding aqueous ammonia to a mixture of an aqueous solution containing iron sulfate (FeSO 4 ㆍ7H 2 O), phosphoric acid (H 3 PO 4 ), and antioxidants, and lithium aqueous solution (LiOHㆍH 2 O) to pH 6. did. Afterwards, a LiFePO 4 solution was prepared by adding the anode slurry at a constant rate under the conditions of 400 ° C. and 270 bar in a continuous process supercritical reactor, and the LiFePO 4 solution was washed and filtered to obtain LiFePO 4 particles .
상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제2 양극 활물질을 제조하였다.The second positive electrode active material was prepared by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5.
<양극 제조><Anode manufacturing>
15 ㎛ 두께의 알루미늄(Al)의 일면에 상기 제1 양극 활물질을 도포하였으며, 상기 알루미늄의 타면에는 상기 제2 양극 활물질을 도포한 후 건조하였다. 이후, 건조가 완료된 상기 제1 양극 활물질 및 상기 제2 양극 활물질을 압연하여 상기 알루미늄 상에 제1 양극 활물질층 및 제2 양극 활물질층이 형성된 양극을 제조하였다. The first positive electrode active material was applied to one side of aluminum (Al) with a thickness of 15 μm, and the second positive electrode active material was applied to the other side of the aluminum and then dried. Thereafter, the dried first and second positive electrode active materials were rolled to manufacture a positive electrode in which a first and second positive electrode active material layers were formed on the aluminum.
<이차 전지 제조><Secondary battery manufacturing>
탄소계 음극 및 상기 제조된 양극 사이에 두께 25 ㎛의 폴리에틸렌 소재의 분리막을 개재하여 전극 조립체를 제조한 후, 상기 전극 조립체를 케이스에 수납하고, 케이스 내부에 에틸렌 카보네이트:메틸에틸카보네이트가 2:1의 부피비로 혼합된 용매에 LiPF6 1M 및 비닐카보네이트 2.5 중량%로 혼합된 전해액을 투입하여 이차 전지를 제조하였다. After manufacturing an electrode assembly by interposing a separator made of polyethylene with a thickness of 25 ㎛ between the carbon-based cathode and the manufactured anode, the electrode assembly is stored in a case, and ethylene carbonate:methylethyl carbonate is mixed in a ratio of 2:1 inside the case. A secondary battery was manufactured by adding an electrolyte solution containing 1M LiPF 6 and 2.5% by weight of vinyl carbonate to a solvent mixed at a volume ratio of .
비교예 3Comparative Example 3
<제1 양극 활물질 제조><Manufacture of first positive electrode active material>
황산철(FeSO4ㆍ7H2O), 인산(H3PO4), 및 산화 방지제를 포함한 수용액과 리튬 수용액(LiOHㆍH2O)의 혼합물에 pH 6이 되도록 암모니아수를 첨가하여 양극 슬러리를 제조하였다. 이후, 연속 공정 초임계 반응기에서 400 ℃ 및 270 bar의 조건하에 상기 양극 슬러리를 일정 속도로 투입하여 LiFePO4 용액을 제조하였으며, 상기 LiFePO4 용액을 수세 및 여과하여 LiFePO4 입자를 수득하였다. Prepare a positive electrode slurry by adding aqueous ammonia to a mixture of an aqueous solution containing iron sulfate (FeSO 4 ㆍ7H 2 O), phosphoric acid (H 3 PO 4 ), and antioxidants, and lithium aqueous solution (LiOHㆍH 2 O) to pH 6. did. Afterwards, a LiFePO 4 solution was prepared by adding the anode slurry at a constant rate under the conditions of 400 ° C. and 270 bar in a continuous process supercritical reactor, and the LiFePO 4 solution was washed and filtered to obtain LiFePO 4 particles .
상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제1 양극 활물질을 제조하였다.The first positive electrode active material was prepared by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5.
<제2 양극 활물질 제조><Manufacture of second positive electrode active material>
황산철(FeSO4ㆍ7H2O), 인산(H3PO4), 질산나트륨(NaNo3) 및 산화 방지제를 포함한 수용액과 리튬 수용액(LiOHㆍH2O)의 혼합물에 pH 6이 되도록 암모니아수를 첨가하여 양극 슬러리를 제조하였다. 이후, 연속 공정 초임계 반응기에서 400 
상기 LiFePO4 입자, Super-P, 폴리비닐리덴플로오라이드를 95:2.5:2.5의 중량비로 N-메틸 피롤리돈 용매 중에서 혼합하여 제2 양극 활물질을 제조하였다.The second positive electrode active material was prepared by mixing the LiFePO 4 particles, Super-P, and polyvinylidene fluoride in N-methyl pyrrolidone solvent at a weight ratio of 95:2.5:2.5.
<양극 제조><Anode manufacturing>
15 ㎛ 두께의 알루미늄(Al)의 일면에 상기 제1 양극 활물질을 도포하였으며, 상기 알루미늄의 타면에는 상기 제2 양극 활물질을 도포한 후 건조하였다. 이후, 건조가 완료된 상기 제1 양극 활물질 및 상기 제2 양극 활물질을 압연하여 상기 알루미늄 상에 제1 양극 활물질층 및 제2 양극 활물질층이 형성된 양극을 제조하였다. The first positive electrode active material was applied to one side of aluminum (Al) with a thickness of 15 μm, and the second positive electrode active material was applied to the other side of the aluminum and then dried. Thereafter, the dried first and second positive electrode active materials were rolled to manufacture a positive electrode in which a first and second positive electrode active material layers were formed on the aluminum.
<이차 전지 제조><Secondary battery manufacturing>
탄소계 음극 및 상기 제조된 양극 사이에 두께 25 ㎛의 폴리에틸렌 소재의 분리막을 개재하여 전극 조립체를 제조한 후, 상기 전극 조립체를 케이스에 수납하고, 케이스 내부에 에틸렌 카보네이트:메틸에틸카보네이트가 2:1의 부피비로 혼합된 용매에 LiPF6 1M 및 비닐카보네이트 2.5 중량%로 혼합된 전해액을 투입하여 이차 전지를 제조하였다. After manufacturing an electrode assembly by interposing a separator made of polyethylene with a thickness of 25 ㎛ between the carbon-based cathode and the manufactured anode, the electrode assembly is stored in a case, and ethylene carbonate:methylethyl carbonate is mixed in a ratio of 2:1 inside the case. A secondary battery was manufactured by adding an electrolyte solution containing 1M LiPF 6 and 2.5% by weight of vinyl carbonate to a solvent mixed at a volume ratio of .
실험예Experiment example
실험예 1 - 고율 특성 평가Experimental Example 1 - High rate characteristic evaluation
상기 실시예 1 내지 6 및 비교예 1 내지 3에서 제조된 각각의 이차 전지를 상온에서 리튬 금속 대비 2.5V 내지 4.1V의 전압 범위에서 0.1C rate의 정전류로 충전시키면서, 방전시의 전류밀도가 증가함에 따른 방전용량을 얻고 이로부터 율별 충방전 효율을 계산하였다. 방전시의 전류밀도는 각각 0.1C, 0.2C, 0.5C, 1C 및 2C rate였다. 2C에서의 충방전 효율은 하기 식 1에 의해 계산하였으며, 그 결과를 하기 표 1에 나타내었다.While each secondary battery manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 was charged at a constant current of 0.1C rate in a voltage range of 2.5V to 4.1V relative to lithium metal at room temperature, the current density during discharging increased. The discharge capacity was obtained and the charge/discharge efficiency for each rate was calculated from this. The current densities during discharge were 0.1C, 0.2C, 0.5C, 1C, and 2C rates, respectively. The charge/discharge efficiency at 2C was calculated using Equation 1 below, and the results are shown in Table 1 below.
[식 1][Equation 1]
2C에서의 충방전 효율(%)=[2C 방전용량/0.1C 충전용량]Х100Charge/discharge efficiency at 2C (%)=[2C discharge capacity/0.1C charge capacity]Х100
실험예 2 - 수명 특성 평가Experimental Example 2 - Evaluation of lifespan characteristics
상기 실시예 1 내지 6 및 비교예 1 내지 3에서 제조된 각각의 이차 전지를 상온에서 리튬 금속 대비 2.5V 내지 4.1V의 전압 범위에서 1C rate의 정전류로 충방전시키면서 용량유지율 및 500번째 사이클에서의 방전용량을 측정하였다. 상온에서 용량유지율은 하기 식 2에 의해 계산하였으며, 그 결과를 하기 표 1에 나타내었다.Each of the secondary batteries manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 were charged and discharged at a constant current of 1C rate in a voltage range of 2.5V to 4.1V relative to lithium metal at room temperature, and the capacity retention rate and the 500th cycle were measured. Discharge capacity was measured. The capacity retention rate at room temperature was calculated using Equation 2 below, and the results are shown in Table 1 below.
[식 2][Equation 2]
용량유지율(%) = [500번째 사이클에서의 방전용량/1번째 사이클에서의 방전용량]Х100Capacity maintenance rate (%) = [discharge capacity at 500th cycle/discharge capacity at 1st cycle]Х100
실험예 3 - 전압 강하 평가Experimental Example 3 - Voltage drop evaluation
상기 실시예 1 내지 6 및 비교예 1 내지 3에서 제조된 각각의 이차 전지를 양극 전위 기준 4.5V 내지 2.5V의 전압 범위에서 SOC에 따른 전압 강하를 측정하였다. SOC 10% 내지 SOC 90%의 구간에서 급격한 전압 강하가 발생하는 구간을 하기 기준으로 평가하였으며, 그 결과를 하기 표 1에 나타내었다.The voltage drop according to SOC was measured for each secondary battery manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 in a voltage range of 4.5V to 2.5V based on the anode potential. The section where a sharp voltage drop occurs in the section from SOC 10% to SOC 90% was evaluated based on the following criteria, and the results are shown in Table 1 below.
- ○: 전 구간에 걸쳐 전압 강하가 완만하게 진행됨- ○: Voltage drop progresses gently throughout the entire section.
- △: 1개의 구간에서 전압 강하가 급격하게 진행됨- △: Voltage drop occurs rapidly in one section
- ×: 2개 이상의 구간에서 전압 강하가 급격하게 진행됨- ×: Voltage drop occurs rapidly in two or more sections
충방전 효율(%)in 2C
Charge/discharge efficiency (%)
유지율
(%)Volume
retention rate
(%)
(mAh/g)Discharge capacity at 500th cycle
(mAh/g)
상기 표 1에서 확인할 수 있는 바와 같이, 양극 집전체의 일면에 지르코늄이 도핑된 리튬철 인산화물계 활물질을 포함하며, 양극 집전체의 타면에 나트륨이 도핑된 리튬철 인산화물계 활물질을 포함하는 실시예 1 내지 6은 비교예 1 내지 3 대비 전압 강화 현상이 최소화되며, 고율 특성이 우수하고, 방전속도(C-rate)의 증가에 따른 용량 유지율이 우수한 것을 확인할 수 있었다. 또한, 실시예 1 내지 6은 비교예 1 내지 3 대비 수명 특성 및 방전 용량이 현저히 향상된 것을 확인할 수 있었다. 즉, 본 발명에 따른 양극을 포함하는 실시예 1 내지 6은 전압 강화 현상이 최소화되며, 고율 특성이 우수한 동시에 수명 특성 및 방전 용량도 향상된 것을 확인할 수 있었다.As can be seen in Table 1, Example 1 includes a lithium iron phosphate-based active material doped with zirconium on one side of the positive electrode current collector, and a lithium iron phosphate-based active material doped with sodium on the other side of the positive electrode current collector. It was confirmed that in Examples 6 to 6, compared to Comparative Examples 1 to 3, the voltage enhancement phenomenon was minimized, the high rate characteristics were excellent, and the capacity retention rate according to the increase in discharge rate (C-rate) was excellent. In addition, it was confirmed that Examples 1 to 6 had significantly improved lifespan characteristics and discharge capacity compared to Comparative Examples 1 to 3. That is, it was confirmed that Examples 1 to 6 including the positive electrode according to the present invention minimized the voltage enhancement phenomenon, had excellent high rate characteristics, and also improved life characteristics and discharge capacity.
Claims (5)
상기 집전체의 일면에 형성된 제1 양극 활물질층; 및
상기 집전체의 타면에 형성된 제2 양극 활물질층을 포함하며,
상기 제1 양극 활물질층은 지르코늄(Zr) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하고,
상기 제2 양극 활물질층은 나트륨(Na) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하는 양극.house collector;
A first positive electrode active material layer formed on one side of the current collector; and
It includes a second positive electrode active material layer formed on the other side of the current collector,
The first positive electrode active material layer includes a lithium iron phosphate-based active material doped with zirconium (Zr) element,
The second positive electrode active material layer is a positive electrode containing a lithium iron phosphate-based active material doped with sodium (Na) element.
상기 제1 양극 활물질층은 상기 리튬철 인산화물계 활물질 상에 코팅된 알루미늄(Al) 원소를 포함하는 것인 양극.According to paragraph 1,
The first positive electrode active material layer is a positive electrode comprising aluminum (Al) element coated on the lithium iron phosphate-based active material.
상기 제1 양극 활물질층 및 상기 제2 양극 활물질층 각각은 폴리아크릴아마이드(Polyacrylamide), 폴리우레탄(polyurethane), 및 폴리아크릴로나이트릴(polyacrylonitrile)로 이루어진 군에서 선택되는 1종 이상의 수평균 분자량 30,000 g/mol 내지 80,000 g/mol를 가지는 바인더 응집제를 포함하는 것인 양극.According to paragraph 1,
Each of the first positive electrode active material layer and the second positive electrode active material layer has a number average molecular weight of at least 30,000 selected from the group consisting of polyacrylamide, polyurethane, and polyacrylonitrile. A positive electrode comprising a binder coagulant having g/mol to 80,000 g/mol.
상기 양극은,
집전체;
상기 집전체의 일면에 형성된 제1 양극 활물질층; 및
상기 집전체의 타면에 형성된 제2 양극 활물질층을 포함하며,
상기 제1 양극 활물질층은 지르코늄(zr) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하고,
상기 제2 양극 활물질층은 나트륨(Na) 원소가 도핑된 리튬철 인산화물계 활물질을 포함하는 이차 전지.A secondary battery comprising an anode, a cathode, and a separator interposed between the anode and the cathode,
The anode is,
house collector;
A first positive electrode active material layer formed on one side of the current collector; and
It includes a second positive electrode active material layer formed on the other side of the current collector,
The first positive electrode active material layer includes a lithium iron phosphate-based active material doped with zirconium (zr) element,
The second positive electrode active material layer is a secondary battery comprising a lithium iron phosphate-based active material doped with sodium (Na) element.
상기 음극은 음극 활물질을 포함하는 음극 활물질층을 포함하며, 상기 음극 활물질은 니오비움(niobium)이 도핑된 티타늄-틴-옥사이드(titanium-tin-oxide) 및 상기 니오비움이 도핑된 티타늄-옥사이드(titanium-oxide)중 적어도 하나를 포함하는 것인 이차 전지.
According to paragraph 4,
The negative electrode includes a negative electrode active material layer containing a negative electrode active material, and the negative electrode active material includes niobium-doped titanium-tin-oxide and niobium-doped titanium-oxide ( A secondary battery containing at least one of titanium-oxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020230090280A KR102584305B1 (en) | 2023-07-12 | 2023-07-12 | Positive electrode and secondary battery comprsing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020230090280A KR102584305B1 (en) | 2023-07-12 | 2023-07-12 | Positive electrode and secondary battery comprsing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| KR102584305B1 true KR102584305B1 (en) | 2023-10-05 |
Family
ID=88293489
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020230090280A KR102584305B1 (en) | 2023-07-12 | 2023-07-12 | Positive electrode and secondary battery comprsing the same |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR102584305B1 (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115663111A (en) * | 2022-10-31 | 2023-01-31 | 惠州市豪鹏科技有限公司 | Positive pole piece and quick-charging and quick-discharging type battery |
| JP2023529661A (en) * | 2020-06-17 | 2023-07-11 | ジーアールエスティー・インターナショナル・リミテッド | Positive electrode active material, positive electrode slurry, and positive electrode for secondary battery |
-
2023
- 2023-07-12 KR KR1020230090280A patent/KR102584305B1/en active IP Right Grant
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2023529661A (en) * | 2020-06-17 | 2023-07-11 | ジーアールエスティー・インターナショナル・リミテッド | Positive electrode active material, positive electrode slurry, and positive electrode for secondary battery |
| CN115663111A (en) * | 2022-10-31 | 2023-01-31 | 惠州市豪鹏科技有限公司 | Positive pole piece and quick-charging and quick-discharging type battery |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR102656222B1 (en) | Positive electrode material including lithium manganese-based positive electrode active material having spinel structure, positive electrode and lithium secondary battery including the same | |
| JP6749973B2 (en) | Lithium-nickel positive electrode active material, method for producing the same, and lithium secondary battery including the same | |
| KR101073223B1 (en) | anode mixture for lithium secondary battery and Lithium secondary battery using the same | |
| KR102316342B1 (en) | Silicon-based composite, negative electrode and lithium secondary battery comprising the same | |
| KR102254263B1 (en) | Negative electrode for lithium secondary battery, and lithium secondary battery comprising the same | |
| KR101676085B1 (en) | Silicon based anode active material and lithium secondary battery comprising the same | |
| CN111542496A (en) | Positive electrode active material for secondary battery, method of preparing the same, and lithium secondary battery comprising the same | |
| KR102646131B1 (en) | Positive electrode active material and lithium secondary battery comprising the same | |
| KR102600818B1 (en) | Positive electrode active material and lithium secondary battery comprising the same | |
| KR102335314B1 (en) | Negative electrode for lithium secondary battery, and lithium secondary battery comprising the same | |
| KR102170026B1 (en) | Preparing methode for lithium secondary battery having improved low temperature property and lithium secondary battery | |
| KR102563239B1 (en) | Negative electrode active material, negative electrode and lithium secondary battery comprising the same | |
| KR102621167B1 (en) | Negative electrode for rechargeable lithium battery and rechargeable lithium battery including same | |
| KR102627382B1 (en) | Manufacturing method of positive electrode active material | |
| KR20200085587A (en) | Anode and Lithium Secondary Battery Comprising the Same | |
| KR102584305B1 (en) | Positive electrode and secondary battery comprsing the same | |
| KR102672779B1 (en) | Positive electrode and secondary battery comprsing the same | |
| KR102603798B1 (en) | Positive electrode and secondary battery comprsing the same | |
| KR102672777B1 (en) | Positive electrode and secondary battery comprsing the same | |
| KR102617270B1 (en) | Positive electrode and secondary battery comprsing the same | |
| KR20220144097A (en) | Anode for lithium secondary battery, secondary battery including the same and method of preparing the same | |
| KR102594627B1 (en) | Method for manufacturing positive electrode active material | |
| KR102640291B1 (en) | Negative active materials with improved rate property and negative electrodes comprising the same | |
| KR102553635B1 (en) | Positive electrode active material, positive electrode and secondary battery comprising the same | |
| KR102609878B1 (en) | Positive electrode and secondary battery comprising the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant |