CN116845248A - Composite current collector, pole piece comprising same and electrochemical device - Google Patents
Composite current collector, pole piece comprising same and electrochemical device Download PDFInfo
- Publication number
- CN116845248A CN116845248A CN202310888697.XA CN202310888697A CN116845248A CN 116845248 A CN116845248 A CN 116845248A CN 202310888697 A CN202310888697 A CN 202310888697A CN 116845248 A CN116845248 A CN 116845248A
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- CN
- China
- Prior art keywords
- current collector
- conductive layer
- composite current
- equal
- layer
- 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.)
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- 239000002131 composite material Substances 0.000 title claims abstract description 63
- 239000000758 substrate Substances 0.000 claims abstract description 40
- 239000010410 layer Substances 0.000 claims description 130
- 238000000576 coating method Methods 0.000 claims description 34
- 239000011248 coating agent Substances 0.000 claims description 28
- 239000011241 protective layer Substances 0.000 claims description 23
- 239000000463 material Substances 0.000 claims description 16
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 14
- 229910052782 aluminium Inorganic materials 0.000 claims description 14
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 14
- -1 polypropylene Polymers 0.000 claims description 13
- 239000011247 coating layer Substances 0.000 claims description 8
- 239000004698 Polyethylene Substances 0.000 claims description 5
- 239000004743 Polypropylene Substances 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- 229920000573 polyethylene Polymers 0.000 claims description 5
- 229920001155 polypropylene Polymers 0.000 claims description 5
- 239000004642 Polyimide Substances 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims description 4
- 229920000139 polyethylene terephthalate Polymers 0.000 claims description 4
- 239000005020 polyethylene terephthalate Substances 0.000 claims description 4
- 229920001721 polyimide Polymers 0.000 claims description 4
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 3
- 238000002441 X-ray diffraction Methods 0.000 claims description 3
- 229910000423 chromium oxide Inorganic materials 0.000 claims description 3
- 239000013078 crystal Substances 0.000 claims description 3
- 229910000838 Al alloy Inorganic materials 0.000 claims description 2
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 claims description 2
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 claims description 2
- 229910044991 metal oxide Inorganic materials 0.000 claims description 2
- 150000004706 metal oxides Chemical class 0.000 claims description 2
- 239000010445 mica Substances 0.000 claims description 2
- 229910052618 mica group Inorganic materials 0.000 claims description 2
- 229910052863 mullite Inorganic materials 0.000 claims description 2
- 239000004417 polycarbonate Substances 0.000 claims description 2
- 229920000515 polycarbonate Polymers 0.000 claims description 2
- 239000011112 polyethylene naphthalate Substances 0.000 claims description 2
- 239000004800 polyvinyl chloride Substances 0.000 claims description 2
- 239000000377 silicon dioxide Substances 0.000 claims description 2
- 238000012360 testing method Methods 0.000 abstract description 19
- 238000004880 explosion Methods 0.000 abstract description 10
- 230000008901 benefit Effects 0.000 abstract description 4
- 238000005520 cutting process Methods 0.000 abstract description 3
- 238000013461 design Methods 0.000 abstract description 3
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 12
- 229910052744 lithium Inorganic materials 0.000 description 12
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 11
- 229910001416 lithium ion Inorganic materials 0.000 description 11
- 238000000034 method Methods 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 10
- 239000007774 positive electrode material Substances 0.000 description 10
- 239000011267 electrode slurry Substances 0.000 description 8
- 239000003792 electrolyte Substances 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 229910003002 lithium salt Inorganic materials 0.000 description 7
- 159000000002 lithium salts Chemical class 0.000 description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 239000011230 binding agent Substances 0.000 description 6
- 239000006258 conductive agent Substances 0.000 description 6
- 238000001035 drying Methods 0.000 description 6
- 239000011888 foil Substances 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 239000002904 solvent Substances 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 239000006183 anode active material Substances 0.000 description 5
- 238000001755 magnetron sputter deposition Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 239000002033 PVDF binder Substances 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 4
- 239000010439 graphite Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000007773 negative electrode material Substances 0.000 description 4
- 239000003921 oil Substances 0.000 description 4
- 239000002985 plastic film Substances 0.000 description 4
- 229920006255 plastic film Polymers 0.000 description 4
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 238000004804 winding Methods 0.000 description 4
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- 229910021393 carbon nanotube Inorganic materials 0.000 description 3
- 239000002041 carbon nanotube Substances 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 229910021389 graphene Inorganic materials 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 229920003048 styrene butadiene rubber Chemical class 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 description 2
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 2
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical class [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 2
- 150000001336 alkenes Chemical class 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 239000001768 carboxy methyl cellulose Chemical class 0.000 description 2
- 150000005678 chain carbonates Chemical class 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 239000011889 copper foil Substances 0.000 description 2
- 150000005676 cyclic carbonates Chemical class 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 125000002573 ethenylidene group Chemical group [*]=C=C([H])[H] 0.000 description 2
- FKRCODPIKNYEAC-UHFFFAOYSA-N ethyl propionate Chemical compound CCOC(=O)CC FKRCODPIKNYEAC-UHFFFAOYSA-N 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910003473 lithium bis(trifluoromethanesulfonyl)imide Inorganic materials 0.000 description 2
- MHCFAGZWMAWTNR-UHFFFAOYSA-M lithium perchlorate Chemical compound [Li+].[O-]Cl(=O)(=O)=O MHCFAGZWMAWTNR-UHFFFAOYSA-M 0.000 description 2
- 229910001486 lithium perchlorate Inorganic materials 0.000 description 2
- VDVLPSWVDYJFRW-UHFFFAOYSA-N lithium;bis(fluorosulfonyl)azanide Chemical compound [Li+].FS(=O)(=O)[N-]S(F)(=O)=O VDVLPSWVDYJFRW-UHFFFAOYSA-N 0.000 description 2
- QSZMZKBZAYQGRS-UHFFFAOYSA-N lithium;bis(trifluoromethylsulfonyl)azanide Chemical compound [Li+].FC(F)(F)S(=O)(=O)[N-]S(=O)(=O)C(F)(F)F QSZMZKBZAYQGRS-UHFFFAOYSA-N 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 239000004810 polytetrafluoroethylene Chemical class 0.000 description 2
- 229920001343 polytetrafluoroethylene Chemical class 0.000 description 2
- 229920002635 polyurethane Chemical class 0.000 description 2
- 239000004814 polyurethane Chemical class 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 239000005060 rubber Substances 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000000779 smoke Substances 0.000 description 2
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 description 2
- 229920001027 sodium carboxymethylcellulose Chemical class 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 239000003981 vehicle Substances 0.000 description 2
- ZZXUZKXVROWEIF-UHFFFAOYSA-N 1,2-butylene carbonate Chemical compound CCC1COC(=O)O1 ZZXUZKXVROWEIF-UHFFFAOYSA-N 0.000 description 1
- PPMCFKAXXHZLMX-UHFFFAOYSA-N 1,3-dioxocan-2-one Chemical compound O=C1OCCCCCO1 PPMCFKAXXHZLMX-UHFFFAOYSA-N 0.000 description 1
- HNAGHMKIPMKKBB-UHFFFAOYSA-N 1-benzylpyrrolidine-3-carboxamide Chemical compound C1C(C(=O)N)CCN1CC1=CC=CC=C1 HNAGHMKIPMKKBB-UHFFFAOYSA-N 0.000 description 1
- IRPGOXJVTQTAAN-UHFFFAOYSA-N 2,2,3,3,3-pentafluoropropanal Chemical compound FC(F)(F)C(F)(F)C=O IRPGOXJVTQTAAN-UHFFFAOYSA-N 0.000 description 1
- UHOPWFKONJYLCF-UHFFFAOYSA-N 2-(2-sulfanylethyl)isoindole-1,3-dione Chemical compound C1=CC=C2C(=O)N(CCS)C(=O)C2=C1 UHOPWFKONJYLCF-UHFFFAOYSA-N 0.000 description 1
- KLZUFWVZNOTSEM-UHFFFAOYSA-K Aluminum fluoride Inorganic materials F[Al](F)F KLZUFWVZNOTSEM-UHFFFAOYSA-K 0.000 description 1
- 229920002799 BoPET Polymers 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 1
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 1
- JGFBQFKZKSSODQ-UHFFFAOYSA-N Isothiocyanatocyclopropane Chemical compound S=C=NC1CC1 JGFBQFKZKSSODQ-UHFFFAOYSA-N 0.000 description 1
- 229910007857 Li-Al Inorganic materials 0.000 description 1
- 229910015013 LiAsF Inorganic materials 0.000 description 1
- 229910013188 LiBOB Inorganic materials 0.000 description 1
- 229910013872 LiPF Inorganic materials 0.000 description 1
- 101150058243 Lipf gene Proteins 0.000 description 1
- 229910008447 Li—Al Inorganic materials 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- RJUFJBKOKNCXHH-UHFFFAOYSA-N Methyl propionate Chemical compound CCC(=O)OC RJUFJBKOKNCXHH-UHFFFAOYSA-N 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical group CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 229910001128 Sn alloy Inorganic materials 0.000 description 1
- 229910020923 Sn-O Inorganic materials 0.000 description 1
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000002174 Styrene-butadiene Substances 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- PTFCDOFLOPIGGS-UHFFFAOYSA-N Zinc dication Chemical compound [Zn+2] PTFCDOFLOPIGGS-UHFFFAOYSA-N 0.000 description 1
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical class [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 1
- OBNDGIHQAIXEAO-UHFFFAOYSA-N [O].[Si] Chemical compound [O].[Si] OBNDGIHQAIXEAO-UHFFFAOYSA-N 0.000 description 1
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- OBNCKNCVKJNDBV-UHFFFAOYSA-N butanoic acid ethyl ester Natural products CCCC(=O)OCC OBNCKNCVKJNDBV-UHFFFAOYSA-N 0.000 description 1
- PWLNAUNEAKQYLH-UHFFFAOYSA-N butyric acid octyl ester Natural products CCCCCCCCOC(=O)CCC PWLNAUNEAKQYLH-UHFFFAOYSA-N 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000002134 carbon nanofiber Substances 0.000 description 1
- 150000007942 carboxylates Chemical class 0.000 description 1
- 150000001733 carboxylic acid esters Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 229910000428 cobalt oxide Inorganic materials 0.000 description 1
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- VUPKGFBOKBGHFZ-UHFFFAOYSA-N dipropyl carbonate Chemical compound CCCOC(=O)OCCC VUPKGFBOKBGHFZ-UHFFFAOYSA-N 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 description 1
- DVATZODUVBMYHN-UHFFFAOYSA-K lithium;iron(2+);manganese(2+);phosphate Chemical compound [Li+].[Mn+2].[Fe+2].[O-]P([O-])([O-])=O DVATZODUVBMYHN-UHFFFAOYSA-K 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- LBSANEJBGMCTBH-UHFFFAOYSA-N manganate Chemical compound [O-][Mn]([O-])(=O)=O LBSANEJBGMCTBH-UHFFFAOYSA-N 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229940017219 methyl propionate Drugs 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- UUIQMZJEGPQKFD-UHFFFAOYSA-N n-butyric acid methyl ester Natural products CCCC(=O)OC UUIQMZJEGPQKFD-UHFFFAOYSA-N 0.000 description 1
- 229910021382 natural graphite Inorganic materials 0.000 description 1
- 229910000480 nickel oxide Inorganic materials 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000002153 silicon-carbon composite material Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000009461 vacuum packaging Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical group O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc 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
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/665—Composites
- H01M4/667—Composites in the form of layers, e.g. coatings
-
- 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
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
-
- 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
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/661—Metal or alloys, e.g. alloy coatings
-
- 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
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/661—Metal or alloys, e.g. alloy coatings
- H01M4/662—Alloys
Abstract
The invention provides a composite current collector, a pole piece comprising the composite current collector and an electrochemical device. The composite current collector includes a substrate layer and a conductive layer; the conductive layer comprises at least two grooves, wherein an angle R between the grooves is more than or equal to 60 degrees and less than or equal to 120 degrees, and a net-shaped structure is formed between the grooves; the conductive layer can form an integral electronic loop, and the design advantage of the conductive layer with the net structure is that when the battery has local short circuit and high current, the conductive layer can realize the timely cutting off of the current when the battery is fused at high temperature, so that the ignition explosion caused by thermal runaway of the battery is prevented, and the passing rate of the battery needling test is improved.
Description
Technical Field
The invention relates to the technical field of lithium batteries, in particular to a composite current collector, a pole piece comprising the composite current collector and an electrochemical device.
Background
The lithium ion battery has the advantages of large battery capacity, long cycle life and the like, and is widely applied to different products, such as notebook computers, portable mobile phones, new energy vehicles and the like. However, the lithium ion battery has the defects of expansion, lithium precipitation of the negative electrode and the like in the use process, and has the potential safety hazards of easy internal short circuit, fire and explosion of the battery due to the puncture of the diaphragm.
At present, a rolled aluminum foil is generally used as a positive current collector, a rolled copper foil is used as a negative current collector, but in the use process, the battery can have the adverse problems of expansion, negative lithium precipitation and the like, and meanwhile, the potential safety hazard of internal short circuit, fire and even explosion of the battery caused by diaphragm puncture and rupture exists.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides a composite current collector, and a pole piece and an electrochemical device comprising the composite current collector. The composite current collector includes a substrate layer and a conductive layer; the conductive layer comprises at least two grooves, wherein an angle R between the grooves is more than or equal to 60 degrees and less than or equal to 120 degrees, and a net-shaped structure is formed between the grooves; the conductive layer can form an integral electronic loop, and the design advantage of the conductive layer with the net structure is that when the battery has local short circuit and high current, the conductive layer can cut off the current in time when fusing at high temperature, so that the battery is prevented from suffering fire explosion caused by thermal runaway, and the passing rate of the battery needling test is improved.
The invention aims at realizing the following technical scheme:
a composite current collector comprising a substrate layer and a conductive layer; the conductive layer comprises at least two grooves, and an angle R between the grooves is more than or equal to 60 degrees and less than or equal to 120 degrees.
The invention also provides a positive plate, which comprises the composite current collector.
The invention also provides an electrochemical device which comprises the composite current collector and/or the positive plate.
The invention has the beneficial effects that:
the invention provides a composite current collector, a pole piece comprising the composite current collector and an electrochemical device. The composite current collector includes a substrate layer and a conductive layer; the conductive layer comprises at least two grooves, wherein an angle R between the grooves is more than or equal to 60 degrees and less than or equal to 120 degrees, and a net-shaped structure is formed between the grooves; the conductive layer can form an integral electronic loop, and the design advantage of the conductive layer with the net structure is that when the battery has local short circuit and high current, the conductive layer can realize the timely cutting off of the current when the battery is fused at high temperature, so that the ignition explosion caused by thermal runaway of the battery is prevented, and the passing rate of the battery needling test is improved.
Drawings
Fig. 1 is a schematic structural view of a composite current collector according to a preferred embodiment of the present invention.
Fig. 2 is a schematic structural view of a composite current collector according to a preferred embodiment of the present invention.
Reference numerals: 11 is a substrate layer, 21 is a first coating layer, 31 is a conductive layer, and 41 is a protective layer; 12 is a conductive region; 22 is a slot; 32 are conductive connection areas.
Detailed Description
As described above, the present invention provides a composite current collector including a substrate layer and a conductive layer; the conductive layer comprises at least two grooves, and an angle R between the grooves is more than or equal to 60 degrees and less than or equal to 120 degrees.
According to the embodiment of the invention, when the angle R between the grooves is more than or equal to 60 degrees and less than or equal to 120 degrees, if the battery has a local short circuit and high current, the conducting layer can be fused at a high temperature to cut off the current in time, so that the battery is prevented from being ignited and exploded due to thermal runaway, and the passing rate of the battery needling test is improved; when the angle R between the grooves is not more than 60 degrees and less than or equal to 120 degrees, namely, when the angle R between the grooves is less than 60 degrees or more than 120 degrees, if the battery is in a local short circuit and high current moment, the conducting layer cannot be fused at a high temperature to cut off the current in time, so that the ignition explosion caused by thermal runaway of the battery cannot be effectively prevented, and the passing rate of the battery needling test cannot be improved.
According to an embodiment of the invention, the grooves extend through the conductive layer.
According to an embodiment of the present invention, the shape of the groove is not particularly limited, and may be regular or irregular. Illustratively, the shape of the slot is at least one of square, circular, oval, diamond, triangular, or the like. Preferably, the shape of the groove is elliptical, and the ratio of the major axis to the minor axis of the ellipse is 1 to 10. Illustratively, the major axis is 3 to 8mm (e.g., 5 mm) in length and the minor axis is 0.3 to 3mm (e.g., 1 mm) in length.
According to an embodiment of the invention, the composite current collector further comprises a first coating and/or a protective layer; the protective layer is arranged on the surface of the conductive layer, and the conductive layer is arranged on the surface of the substrate layer; or the conductive layer is arranged on the surface of the first coating, and the first coating is arranged on the surface of the substrate layer; or, the protective layer is arranged on the surface of the conductive layer, the conductive layer is arranged on the surface of the first coating, and the first coating is arranged on the surface of the substrate layer.
According to an embodiment of the invention, the conductive layer is provided with a mesh structure, and the mesh structure is formed by a plurality of grooves, namely, a mesh structure is formed between the grooves.
According to an embodiment of the invention, at least three adjacent slots share a vertex forming a conductive connection area, e.g. three or four adjacent slots share a vertex forming a conductive connection area.
According to the embodiment of the invention, the conductive layer can be used as an electron channel, penetrates through the whole current collector and normally plays an electron transmission function in lithium ion battery application; the conductive layer (particularly the conductive connection area) can also be used as a fuse, when the local conductive layer is abnormal due to short circuit, high current passes through the conductive layer, the local conductive layer can be evaporated due to instantaneous high temperature, the current is cut off in time, the abnormal area is independent, and the rest conductive layers still operate normally.
According to the embodiment of the invention, the net structure can be integrally formed or spliced.
According to an embodiment of the present invention, the mesh structure may be an array-like structure or a random-like structure. Preferably, the mesh structure is an array-like structure, and a composite current collector with uniform performance can be obtained.
According to an embodiment of the invention, the mesh structure fulfils at least one of the following conditions:
(1) The area of the individual grooves in the mesh structure is 1mm 2 To 120mm 2 ；
(2) The ratio of the area of all the grooves in the mesh structure to the total area is 1 to 25%.
Illustratively, the individual channels in the mesh structure have an area of 1mm 2 、2mm 2 、5mm 2 、8mm 2 、10mm 2 、20mm 2 、30mm 2 、40mm 2 、50mm 2 、80mm 2 、90mm 2 Or 100mm 2 。
Illustratively, the ratio of the area of all of the channels in the mesh structure to the total area is 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, or 25%.
It was found that the conductive layer in the composite current collector may form an integrated electronic circuit when the mesh structure satisfies the above conditions. When the battery is in local short circuit and high current, the conductive connection area serving as a fuse can cut off current in time due to high-temperature fusing, so that the battery is prevented from being in fire explosion caused by thermal runaway, and the passing rate of the battery needling test is improved.
According to an embodiment of the invention, the minimum distance between adjacent grooves in the mesh structure is 1mm to 10mm; for example 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm. When the mesh structure satisfies the above conditions, the conductive layer in the composite current collector may form an integrated electronic circuit. When the battery is in local short circuit and high current, the conductive connection area serving as a fuse can cut off current in time due to high-temperature fusing, so that the battery is prevented from being in fire explosion caused by thermal runaway, and the passing rate of the battery needling test is improved.
According to an embodiment of the invention, the maximum distance between adjacent cells in the mesh structure is 1mm to 20mm; for example 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 15mm or 20mm. When the mesh structure satisfies the above conditions, the conductive layer in the composite current collector may form an integrated electronic circuit. When the battery is in local short circuit and high current, the conductive connection area serving as a fuse can cut off current in time due to high-temperature fusing, so that the battery is prevented from being in fire explosion caused by thermal runaway, and the passing rate of the battery needling test is improved.
According to an embodiment of the present invention, the thickness T3 of the conductive layer is 0.4 μm.ltoreq.T3.ltoreq.3μm; for example 0.4 μm, 0.5 μm, 0.8 μm, 1 μm, 1.2 μm, 1.5 μm, 1.8 μm, 2 μm, 2.2 μm, 2.5 μm, 2.8 μm or 3 μm; the manufacturing cost and the manufacturing processability of the conductive layer satisfying this range are optimized. The thickness of the conductive layer is too thin, for example, less than 0.4 μm, and the strength of the composite current collector does not meet the requirements of the battery manufacturing process. The thickness of the conductive layer is too thick, for example, more than 3 μm, which is disadvantageous for increasing the energy density of the lithium ion battery.
According to an embodiment of the present invention, the thickness T0 of the composite current collector is 1 μm.ltoreq.T0.ltoreq.30μm, more preferably 3 μm.ltoreq.T0.ltoreq.15μm, for example 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm, 25 μm, 28 μm or 30 μm.
According to an embodiment of the present invention, the fracture extensibility of the composite current collector is 10% or more. At this time, the composite current collector has excellent mechanical properties and can meet the production and use requirements.
According to an embodiment of the present invention, the tensile strength of the composite current collector is 150MPa or more. At this time, the composite current collector has excellent mechanical properties and can meet the production and use requirements.
According to an embodiment of the invention, the surface dyne value of the composite current collector is greater than 35mN/m. At this time, the composite current collector facilitates the coating of the active material layer.
According to the embodiment of the invention, the density of the substrate layer is far lower than that of the traditional rolled aluminum foil, so that the weight per unit area of the composite current collector is far lower than that of the aluminum foil current collector with the same thickness, the weight reduction of the current collector can be realized, and the energy density of the battery cell is improved. The substrate layer also plays a role in supporting the conductive layer, so that the mechanical stability of the composite current collector is improved; the conductive layer has a net structure, and the grooves in the net structure expose the substrate layer of the composite current collector, so the grooves are insulated, but other areas of the conductive layer are communicated, so that an integral electronic circuit can be formed. When the battery is in local short circuit and high current, the conductive connection area with the fuse function can cut off current in time due to high-temperature fusing, so that the battery is prevented from being in fire explosion caused by thermal runaway, and the passing rate of the battery needling test is improved.
According to an embodiment of the present invention, the substrate layer includes a polymer high molecular material, preferably includes a polymer high molecular material subjected to a biaxial stretching process, and further, the polymer high molecular material includes at least one of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polycarbonate (PC), polyvinyl chloride (PVC), or derivatives thereof.
According to an embodiment of the invention, the thickness T1 of the substrate layer is 1 μm.ltoreq.T1.ltoreq.30μm, more preferably 1.5 μm.ltoreq.T1.ltoreq.10μm, for example 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm, 25 μm, 28 μm or 30 μm. When the thickness of the substrate layer is less than 1 μm, the substrate layer is too thin, which is disadvantageous for mechanical stability of the composite current collector; when the thickness of the base material layer is more than 30 μm, the base material layer is too thick, which is disadvantageous in increasing the energy density of the battery.
According to an embodiment of the present invention, the substrate layer has an elongation at break of 3% or more, more preferably 50% or more. The substrate layer with such elongation at break can provide sufficient mechanical properties for the subsequent composite current collector.
According to an embodiment of the present invention, the melting point of the substrate layer is 80 ℃ to 400 ℃ inclusive of Q0, more preferably 180 ℃ to 300 ℃ inclusive of Q0.
According to an embodiment of the present invention, the surface roughness of the base material layer is 0.05 μm or less Ra 1.0 μm or less, more preferably 0.1 μm or less Ra 0.5 μm or less.
According to an embodiment of the invention, the shrinkage of the substrate layer is less than 4% in an environment of 30 minutes at 150 ℃. Therefore, the substrate layer has good heat resistance, and the contact area of the anode and the cathode can not be further increased due to thermal shrinkage at the moment of short circuit, so that thermal runaway is caused.
According to an embodiment of the present invention, the material forming the first coating layer includes at least one of silica, mica, mullite, aluminum oxide, aluminum nitride, and chromium oxide.
According to an embodiment of the invention, the thickness T2 of the first coating layer is 1 nm.ltoreq.T2.ltoreq.100 nm, more preferably 6 nm.ltoreq.T2.ltoreq.50 nm, for example 1nm, 2nm, 5nm, 8nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 60nm, 70nm, 80nm, 90nm or 100nm. The first coating is positioned between the substrate layer and the conductive layer, and has the main function of increasing the binding force between the substrate layer and the conductive layer, and can resist thermal shock, force impact or electrolyte corrosion without falling off. When the thickness of the first coating is less than 1nm, the first coating is too thin to facilitate adhesion between the conductive layer and the substrate layer; when the thickness of the first coating layer is greater than 100nm, the first coating layer is too thick, which is disadvantageous for an increase in energy density of the battery.
According to an embodiment of the present invention, the material forming the conductive layer includes aluminum or an aluminum alloy, which is an alloy of aluminum and at least one of copper, silver, nickel, zinc, magnesium, and titanium.
According to the embodiment of the invention, when the conductive layer is measured by using X-ray diffraction, the crystal face (111) with characteristic diffraction peaks exists, so that the electron transmission channel of the conductive layer can be effectively improved.
According to an embodiment of the present invention, the surface sheet resistance of the conductive layer ranges from 15mΩ to R0 to 120mΩ, more preferably from 25mΩ to R0 to 80mΩ.
According to an embodiment of the present invention, the material forming the protective layer includes at least one of a metal, a metal oxide, and conductive carbon.
According to an embodiment of the present invention, the material forming the protective layer includes at least one of nickel, chromium, nickel-based alloy, copper-based alloy, aluminum oxide, cobalt oxide, chromium oxide, nickel oxide, graphite, superconducting carbon, carbon black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, metallic titanium, and metallic tantalum.
According to an embodiment of the invention, the thickness T4 of the protective layer is 10 nm.ltoreq.T4.ltoreq.100 nm, more preferably 15 nm.ltoreq.T4.ltoreq.50 nm, for example 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 60nm, 70nm, 80nm, 90nm or 100nm. The lithium salt in the electrolyte can corrode the aluminum layer in the cyclic use process of the lithium battery, and reacts with the lithium salt to generate aluminum fluoride, so that the aluminum layer with thinner original thickness and higher sheet resistance is corroded and consumed, the total internal resistance of the lithium battery is increased, and the long-term use of the battery is not facilitated. The protective layer can effectively block the reaction of the conductive layer and the electrolyte, prevent the conductive layer from being oxidized by oxygen and corroded by the electrolyte, and improve the working stability and the service life of the battery. When the thickness of the protective layer is less than 10nm, the protective layer is too thin to form effective protection; when the thickness of the protective layer is greater than 100nm, the protective layer is too thick, which is disadvantageous for an increase in energy density of the battery.
The invention also provides a preparation method of the composite current collector, which comprises the following steps:
(1) Printing coating shielding oil with the same size as the groove on at least one side surface of the substrate layer;
(2) Adopting a high vacuum magnetron sputtering coating process, and sequentially depositing a first coating, a conductive layer and a protective layer on one side or two side surfaces of the substrate layer in the step (1); or alternatively, the process may be performed,
(2') adopting a high vacuum magnetron sputtering coating process, and sequentially depositing a conductive layer and a protective layer on one side or two side surfaces of the substrate layer in the step (1); or alternatively, the process may be performed,
and (2') adopting a high vacuum magnetron sputtering coating process, and sequentially depositing a first coating and a conductive layer on one side or two side surfaces of the substrate layer in the step (1).
According to the embodiment of the invention, the coating shielding oil can be directly evaporated and removed in the heating process. Therefore, after the first coating layer, the conductive layer and the protective layer are formed by using the high vacuum magnetron sputtering coating process, a step of heating to remove the coating shielding oil may be further included.
The invention also provides a positive plate, which comprises a positive current collector and a positive active material layer. The positive electrode active material layer is disposed on at least one surface of the positive electrode current collector.
According to an embodiment of the present invention, the positive electrode current collector may employ the aforementioned composite current collector.
According to the embodiment of the invention, the metal material forming the conductive layer in the composite current collector of the positive plate is aluminum.
According to an embodiment of the present invention, the positive electrode active material layer includes a positive electrode active material.
In some embodiments, the positive electrode active material comprises at least one of lithium cobaltate, lithium nickelate, lithium manganate, lithium nickelate manganate, lithium iron phosphate, lithium iron manganese phosphate, lithium-rich manganese base.
According to an embodiment of the present invention, the positive electrode active material layer further includes a binder and a conductive agent.
In some embodiments, the binder is selected from at least one of polyvinylidene fluoride, a copolymer of vinylidene fluoride-fluorinated olefin, polytetrafluoroethylene, sodium carboxymethyl cellulose, styrene-butadiene rubber, polyurethane, fluorinated rubber, or polyvinyl alcohol.
In some embodiments, the conductive agent is selected from at least one of conductive carbon black, carbon nanotubes, conductive graphite, or graphene.
According to the embodiment of the invention, the preparation process of the positive plate comprises the following steps: and coating the positive electrode slurry containing the positive electrode active material, the binder, the conductive agent and the solvent for the positive electrode slurry on the positive electrode current collector, drying and cold pressing to obtain the positive electrode plate, and drying (volatilizing and removing the solvent) the positive electrode slurry and cold pressing to form a positive electrode active material layer.
In some embodiments, the solvent for the positive electrode slurry is N-methylpyrrolidone.
The invention also provides a negative electrode sheet comprising a negative electrode current collector and a negative electrode active material layer. The anode active material layer is disposed on at least one surface of the anode current collector.
According to an embodiment of the present invention, the anode active material layer includes an anode active material.
In some embodiments, the negative electrode active material is selected from natural graphite, artificial graphite, mesophase carbon microspheres, hard carbon, soft carbon, silicon-carbon composites, silicon oxygen, li-Sn alloys, li-Sn-O alloys, sn, snO, snO 2 Lithiated TiO of spinel structure 2 -Li 4 Ti 5 O 12 Or at least one of Li-Al alloys.
According to an embodiment of the present invention, the negative polarity material layer further includes a binder and a conductive agent.
In some embodiments, the binder is selected from at least one of polyvinylidene fluoride, a copolymer of vinylidene fluoride-fluorinated olefin, polytetrafluoroethylene, sodium carboxymethyl cellulose, styrene-butadiene rubber, polyurethane, fluorinated rubber, polyvinyl alcohol, or polyacrylic acid (PAA).
In some embodiments, the conductive agent is selected from at least one of conductive carbon black, carbon nanotubes, conductive graphite, or graphene.
According to an embodiment of the invention, the preparation process of the negative plate comprises the following steps: and coating the negative electrode slurry containing the negative electrode active material, the binder, the conductive agent and the solvent for the negative electrode slurry on the negative electrode current collector, drying and cold pressing to obtain the negative electrode sheet, and drying (volatilizing and removing the solvent) the negative electrode slurry to form a negative electrode active material layer.
In some embodiments, the solvent for the negative electrode slurry is deionized water.
The present invention also provides an electrochemical device, which may be a capacitor, a lithium ion battery, a sodium ion battery, or a zinc ion battery. For example, a lithium ion capacitor, a lithium ion primary battery, or a lithium ion secondary battery may be used.
According to an embodiment of the present invention, the electrochemical device includes the aforementioned positive electrode sheet, the aforementioned negative electrode sheet, a separator, and an electrolyte.
In some embodiments, the separator is a polyethylene, polypropylene, polyvinylidene fluoride, or multilayer composite film thereof.
In some embodiments, the electrolyte includes an organic solvent. In some embodiments, the organic solvent comprises one or more of a carbonate and a carboxylate. In some embodiments, the carbonate is selected from at least one of a cyclic carbonate and a chain carbonate. In some embodiments, the cyclic carbonate is selected from at least one of ethylene carbonate, propylene carbonate and halogenated derivatives thereof, butylene carbonate and halogenated derivatives thereof, gamma-butyrolactone and halogenated derivatives thereof, pentylene carbonate and halogenated derivatives thereof. In some embodiments, the chain carbonate is selected from at least one of dimethyl carbonate and its halogenated derivatives, diethyl carbonate and its halogenated derivatives, dipropyl carbonate and its halogenated derivatives, ethyl methyl carbonate and its halogenated derivatives. In some embodiments, the carboxylic acid ester is selected from at least one of ethyl butyrate, methyl butyrate, propyl propionate, ethyl propionate, methyl propionate, ethyl acetate, methyl acetate.
In some embodiments, the electrolyte further comprises a lithium salt. In some embodiments, the lithium salt is selected from one or more of an inorganic lithium salt and an organic lithium salt. In some embodiments, the lithium salt is selected from lithium hexafluorophosphate (LiPF) 6 ) Lithium tetrafluoroborate (LiBF) 4 ) Lithium hexafluoroarsenate (LiAsF) 6 ) Lithium perchlorate (LiClO) 4 ) Lithium bis (fluorosulfonyl) imide (LiLSI), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), lithium bis (oxalato) borate (LiB (C) 2 O 4 ) 2 Abbreviated as LiBOB), lithium difluorooxalato borate (LiBF) 2 (C 2 O 4 )，
In some embodiments, the positive electrode sheet, the separator and the negative electrode sheet are stacked in sequence, so that the separator is positioned between the positive electrode sheet and the negative electrode sheet, then a winding electrode assembly can be obtained through winding, the electrode assembly is placed in a shell, electrolyte is injected, and the battery core can be obtained after the procedures of vacuum packaging, standing, formation, shaping, capacity division and the like. In some embodiments, the cell directly serves as the electrochemical device. In other embodiments, the cell cooperates with a circuit protection plate to form the electrochemical device. In other embodiments, the electrode assembly is a stacked-type electrode assembly.
According to an embodiment of the invention, the housing is a hard shell housing or a flexible housing. The hard shell is made of metal. The flexible housing is for example a metal plastic film, for example an aluminium plastic film, a steel plastic film or the like.
The invention also provides an electronic device comprising the electrochemical device.
According to embodiments of the present invention, the electronic device is, for example, but not limited to, a portable device (such as a cell phone, a notebook computer, a tablet computer, etc.), a vehicle (such as an electric vehicle, an electric train, a ship, and a satellite), an energy storage system, etc. In some embodiments, the electric vehicle is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf car, an electric truck, or the like.
The present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are illustrative only and are not to be construed as limiting the scope of the invention. All techniques implemented based on the above description of the invention are intended to be included within the scope of the invention.
The experimental methods used in the following examples are all conventional methods unless otherwise specified; the reagents, materials, etc. used in the examples described below are commercially available unless otherwise specified.
The tensile strength and elongation at break test methods used in the examples below were carried out according to GB/T1040.3-2006, the sheet resistance was tested according to GB/T15717, and the surface dyne value was tested according to GB/T14216.
Example 1
As shown in fig. 1 and 2, a composite current collector includes a substrate layer, a first coating layer, a conductive layer, and a protective layer; the first coating is arranged on at least one side surface of the substrate layer, the conductive layer is arranged on the surface of the first coating, and the protective layer is arranged on the surface of the conductive layer.
The conductive layer comprises a plurality of grooves, wherein the angle between the grooves is R, and a net structure is formed between the grooves; and four adjacent grooves share one vertex to form a conductive connection area; the conductive layer has a crystal plane (111) having a characteristic diffraction peak when measured by X-ray diffraction.
The composite current collector is prepared by the following steps: selecting a biaxially oriented PET film with the thickness of 6.0 mu m as a positive current collector substrate layer, wherein the melting point of the substrate layer is 264.45 ℃; firstly, printing coating shielding oil with the same size as the groove on the two sides of a substrate layer, and then adopting a high vacuum magnetron sputtering coating process to form a first coating of aluminum oxide with the thickness of 50nm on the two sides of the substrate layer; aluminum with the thickness of 900nm is continuously deposited on the two sides of the first coating to serve as a conductive layer, and finally, a metal tantalum protective layer with the thickness of 50nm is deposited on the two sides of the conductive layer. The composition of the composite current collector of example 1 is shown in tables 1 and 2.
Comparative example 1
A conventional 8 μm rolled pure aluminum foil was selected as a positive electrode current collector for comparison with example 1. The tensile strength and the breaking elongation of the rolled pure aluminum foil are 270MPa and 4 percent respectively, the surface dyne value is 32mN/m, and the sheet resistance value is 3.3mΩ.
Examples 2 to 29 and comparative examples 2 to 3
The difference from example 1 is only that the structure and composition of the composite current collector are different, as shown in tables 1 and 2 below:
table 1 composition of composite current collectors of examples and comparative examples
Table 2 composition of composite current collectors of examples and comparative examples
Preparation of the battery:
the positive electrode active material slurry (lithium cobaltate, conductive carbon black, PVDF in a mass ratio of 97:1:2) was uniformly coated on both sides of the positive electrode current collector described in the above examples and comparative examples, and a compacted density of 4.03g/cm was obtained after drying and rolling 3 The thickness of the single-sided positive electrode active material layer is 43 μm; uniformly coating the anode active material slurry (graphite, conductive carbon black and SBR with the mass ratio of 97:1:2) on two sides of a conventional 5-mu m rolled pure copper foil, and drying and rolling to obtain a compacted density of 1.67g/cm 3 The thickness of the single-sided anode active material layer was 52 μm. And after the tab welding process is finished, the positive plate, the diaphragm and the negative plate are wound together to form a bare winding core, then the bare winding core is placed in a soft-package aluminum-plastic film shell, liquid injection is carried out, and then the working procedures of sealing, formation, separation and the like are carried out, so that the lithium ion battery is finally obtained.
Test example 1
The positive electrode current collectors of examples and comparative examples were subjected to surface sheet resistance testing according to GB/T15717, specifically by laying the current collectors flat on a horizontal plane, uniformly taking 10 measurements using a 4-probe and removing the average, and recording Fang Zuyi the values shown in the table below.
Test example 2
The positive electrode current collectors of examples and comparative examples were subjected to an elongation at break test according to GB/T1040.3-2006, specifically by cutting a 15mm wide, 100mm long sample strip on a tensile jig with an initial distance of 50mm, a tensile speed of 50mm/min, recording the jig displacement of the apparatus at break of Xmm, and finally calculating an elongation at break of (X/50) ×100%, and specific test results are shown in the following table.
Test example 3
The lithium ion batteries (10 in total) manufactured by using the positive electrode current collectors of the examples and the comparative examples were subjected to a full needling test to evaluate the safety performance of the batteries, wherein the fully charged battery cells were placed on a horizontal plane, a long needle with a diameter of 2.5mm was subjected to full needling at the geometric center of the battery cells at a speed of 50mm/min, and the lithium ion batteries failed to pass the test when smoke or fire occurred, and specific test results are shown in the following table.
Table 2 results of performance test of the batteries of examples and comparative examples
As can be seen from the test results of the examples and the comparative examples, the composite current collector of the invention can improve the safety performance of the battery compared with the conventional rolled aluminum foil, and can realize the aim of preventing the battery from generating smoke and fire due to thermal runaway when the battery is subjected to full needling; the composite current collector can be timely fused in the process of internal short circuit of the battery so as to avoid thermal runaway, and the safe use of the battery can be ensured.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A composite current collector, comprising a substrate layer and a conductive layer; the conductive layer comprises at least two grooves, and an angle R between the grooves is more than or equal to 60 degrees and less than or equal to 120 degrees.
2. The composite current collector of claim 1 wherein said slots extend through said conductive layer;
preferably, a mesh structure is formed between the grooves; the network satisfies at least one of the following conditions:
(1) The area of the individual grooves in the mesh structure is 1mm 2 To 120mm 2 ；
(2) The ratio of the area of all the grooves in the mesh structure to the total area is 1 to 25%.
3. The composite current collector of claim 2, wherein a minimum distance between adjacent slots in the mesh structure is 1mm to 10mm;
and/or the maximum distance between adjacent slots in the mesh structure is 1mm to 20mm.
4. A composite current collector according to any one of claims 1-3, wherein the thickness T0 of the composite current collector is 1 μm +.t0 +.30μm;
and/or, the fracture extensibility of the composite current collector is greater than or equal to 10%;
and/or, the tensile strength of the composite current collector is greater than or equal to 150MPa;
and/or the surface dyne value of the composite current collector is greater than 35mN/m.
5. The composite current collector according to any one of claims 1 to 4, wherein the substrate layer comprises a polymeric high molecular material comprising at least one of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polycarbonate (PC), polyvinylchloride (PVC) or derivatives thereof;
and/or the thickness T1 of the substrate layer is not less than 1 mu m and not more than 30 mu m.
6. The composite current collector of any of claims 1-5, further comprising a first coating and/or protective layer; the protective layer is arranged on the surface of the conductive layer, and the conductive layer is arranged on the surface of the substrate layer;
or the conductive layer is arranged on the surface of the first coating, and the first coating is arranged on the surface of the substrate layer;
or the protective layer is arranged on the surface of the conductive layer, the conductive layer is arranged on the surface of the first coating, and the first coating is arranged on the surface of the substrate layer.
7. The composite current collector of claim 6 wherein the material of said first coating comprises at least one of silica, mica, mullite, aluminum oxide, aluminum nitride, chromium oxide;
and/or the thickness T2 of the first coating is not less than 1nm and not more than 100nm;
and/or the material forming the protective layer includes at least one of a metal, a metal oxide, and conductive carbon;
and/or the thickness T4 of the protective layer is more than or equal to 10nm and less than or equal to T4 and less than or equal to 100nm.
8. The composite current collector of any of claims 1-7 wherein the material of said conductive layer comprises aluminum or an aluminum alloy;
and/or, when the conductive layer is measured using X-ray diffraction, a crystal plane (111) having a characteristic diffraction peak is present;
and/or the thickness T3 of the conductive layer is more than or equal to 0.4 mu m and less than or equal to T3 mu m;
and/or, the surface sheet resistance value R0 of the conductive layer is 15mΩ less than or equal to R0 less than or equal to 120mΩ.
9. A positive electrode sheet comprising the composite current collector of claims 1-8.
10. An electrochemical device comprising the composite current collector of any one of claims 1-8 and/or the positive electrode sheet of claim 9.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310888697.XA CN116845248A (en) | 2023-07-19 | 2023-07-19 | Composite current collector, pole piece comprising same and electrochemical device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310888697.XA CN116845248A (en) | 2023-07-19 | 2023-07-19 | Composite current collector, pole piece comprising same and electrochemical device |
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| CN116845248A true CN116845248A (en) | 2023-10-03 |
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| CN (1) | CN116845248A (en) |
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