CN115000514A - Electrolyte, negative electrode, lithium ion battery and vehicle - Google Patents
Electrolyte, negative electrode, lithium ion battery and vehicle Download PDFInfo
- Publication number
- CN115000514A CN115000514A CN202110224657.6A CN202110224657A CN115000514A CN 115000514 A CN115000514 A CN 115000514A CN 202110224657 A CN202110224657 A CN 202110224657A CN 115000514 A CN115000514 A CN 115000514A
- Authority
- CN
- China
- Prior art keywords
- electrolyte
- lithium
- carbonate
- negative electrode
- additive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003792 electrolyte Substances 0.000 title claims abstract description 69
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 31
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 31
- 239000000654 additive Substances 0.000 claims abstract description 55
- 230000000996 additive effect Effects 0.000 claims abstract description 47
- -1 thiadiazole compound Chemical class 0.000 claims abstract description 45
- 239000003960 organic solvent Substances 0.000 claims abstract description 12
- 125000005865 C2-C10alkynyl group Chemical group 0.000 claims abstract description 10
- 125000000753 cycloalkyl group Chemical group 0.000 claims abstract description 10
- 229910003002 lithium salt Inorganic materials 0.000 claims abstract description 10
- 159000000002 lithium salts Chemical class 0.000 claims abstract description 10
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims abstract description 9
- 125000005843 halogen group Chemical group 0.000 claims abstract description 8
- 125000001424 substituent group Chemical group 0.000 claims abstract description 8
- 125000003277 amino group Chemical group 0.000 claims abstract description 4
- 125000001033 ether group Chemical group 0.000 claims abstract description 4
- 239000006259 organic additive Substances 0.000 claims abstract description 4
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 18
- 229910052744 lithium Inorganic materials 0.000 claims description 18
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 claims description 16
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 claims description 12
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims description 9
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 claims description 6
- 230000015572 biosynthetic process Effects 0.000 claims description 6
- FKRCODPIKNYEAC-UHFFFAOYSA-N ethyl propionate Chemical compound CCOC(=O)CC FKRCODPIKNYEAC-UHFFFAOYSA-N 0.000 claims description 6
- TZIHFWKZFHZASV-UHFFFAOYSA-N methyl formate Chemical compound COC=O TZIHFWKZFHZASV-UHFFFAOYSA-N 0.000 claims description 6
- 239000007773 negative electrode material Substances 0.000 claims description 6
- 230000001681 protective effect Effects 0.000 claims description 6
- FSSPGSAQUIYDCN-UHFFFAOYSA-N 1,3-Propane sultone Chemical compound O=S1(=O)CCCO1 FSSPGSAQUIYDCN-UHFFFAOYSA-N 0.000 claims description 4
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 claims description 4
- GWAOOGWHPITOEY-UHFFFAOYSA-N 1,5,2,4-dioxadithiane 2,2,4,4-tetraoxide Chemical compound O=S1(=O)CS(=O)(=O)OCO1 GWAOOGWHPITOEY-UHFFFAOYSA-N 0.000 claims description 4
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 claims description 4
- 125000004093 cyano group Chemical group *C#N 0.000 claims description 4
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 claims description 4
- IGILRSKEFZLPKG-UHFFFAOYSA-M lithium;difluorophosphinate Chemical compound [Li+].[O-]P(F)(F)=O IGILRSKEFZLPKG-UHFFFAOYSA-M 0.000 claims description 4
- ZZXUZKXVROWEIF-UHFFFAOYSA-N 1,2-butylene carbonate Chemical compound CCC1COC(=O)O1 ZZXUZKXVROWEIF-UHFFFAOYSA-N 0.000 claims description 3
- HFZLSTDPRQSZCQ-UHFFFAOYSA-N 1-pyrrolidin-3-ylpyrrolidine Chemical compound C1CCCN1C1CNCC1 HFZLSTDPRQSZCQ-UHFFFAOYSA-N 0.000 claims description 3
- 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 claims description 3
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 claims description 3
- DKPFZGUDAPQIHT-UHFFFAOYSA-N Butyl acetate Natural products CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 claims description 3
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 claims description 3
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 claims description 3
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 3
- VEWLDLAARDMXSB-UHFFFAOYSA-N ethenyl sulfate;hydron Chemical compound OS(=O)(=O)OC=C VEWLDLAARDMXSB-UHFFFAOYSA-N 0.000 claims description 3
- FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 claims description 3
- MHCFAGZWMAWTNR-UHFFFAOYSA-M lithium perchlorate Chemical compound [Li+].[O-]Cl(=O)(=O)=O MHCFAGZWMAWTNR-UHFFFAOYSA-M 0.000 claims description 3
- 229910001486 lithium perchlorate Inorganic materials 0.000 claims description 3
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 claims description 3
- 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 claims description 3
- KKQAVHGECIBFRQ-UHFFFAOYSA-N methyl propyl carbonate Chemical compound CCCOC(=O)OC KKQAVHGECIBFRQ-UHFFFAOYSA-N 0.000 claims description 3
- YKYONYBAUNKHLG-UHFFFAOYSA-N n-Propyl acetate Natural products CCCOC(C)=O YKYONYBAUNKHLG-UHFFFAOYSA-N 0.000 claims description 3
- 229940090181 propyl acetate Drugs 0.000 claims description 3
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 claims description 3
- 125000000542 sulfonic acid group Chemical group 0.000 claims description 3
- NQPDZGIKBAWPEJ-UHFFFAOYSA-N valeric acid Chemical compound CCCCC(O)=O NQPDZGIKBAWPEJ-UHFFFAOYSA-N 0.000 claims description 3
- WDXYVJKNSMILOQ-UHFFFAOYSA-N 1,3,2-dioxathiolane 2-oxide Chemical compound O=S1OCCO1 WDXYVJKNSMILOQ-UHFFFAOYSA-N 0.000 claims description 2
- IFDLFCDWOFLKEB-UHFFFAOYSA-N 2-methylbutylbenzene Chemical compound CCC(C)CC1=CC=CC=C1 IFDLFCDWOFLKEB-UHFFFAOYSA-N 0.000 claims description 2
- PMGNOQUKCGLETL-UHFFFAOYSA-N carbonic acid 1,2-difluoroethene Chemical compound C(O)(O)=O.FC=CF PMGNOQUKCGLETL-UHFFFAOYSA-N 0.000 claims description 2
- ABDBNWQRPYOPDF-UHFFFAOYSA-N carbonofluoridic acid Chemical compound OC(F)=O ABDBNWQRPYOPDF-UHFFFAOYSA-N 0.000 claims description 2
- AUBNQVSSTJZVMY-UHFFFAOYSA-M P(=O)([O-])(O)O.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.[Li+] Chemical compound P(=O)([O-])(O)O.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.[Li+] AUBNQVSSTJZVMY-UHFFFAOYSA-M 0.000 claims 1
- 230000009467 reduction Effects 0.000 abstract description 19
- 230000000052 comparative effect Effects 0.000 description 22
- 238000006722 reduction reaction Methods 0.000 description 20
- 238000012360 testing method Methods 0.000 description 17
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 16
- 229910052710 silicon Inorganic materials 0.000 description 16
- 239000010703 silicon Substances 0.000 description 16
- 230000009286 beneficial effect Effects 0.000 description 15
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical group FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 description 13
- 238000000034 method Methods 0.000 description 12
- 238000003860 storage Methods 0.000 description 10
- 239000002904 solvent Substances 0.000 description 9
- 229920000642 polymer Polymers 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 238000006116 polymerization reaction Methods 0.000 description 7
- 229940021013 electrolyte solution Drugs 0.000 description 6
- 230000008901 benefit Effects 0.000 description 5
- 230000008859 change Effects 0.000 description 5
- 230000014759 maintenance of location Effects 0.000 description 5
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 4
- 239000008151 electrolyte solution Substances 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 125000004433 nitrogen atom Chemical group N* 0.000 description 4
- YOTIBQOCCYWJMZ-UHFFFAOYSA-N 1,2,5-thiadiazole 1,1-dioxide Chemical compound O=S1(=O)N=CC=N1 YOTIBQOCCYWJMZ-UHFFFAOYSA-N 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 239000011203 carbon fibre reinforced carbon Substances 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 238000004768 lowest unoccupied molecular orbital Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000002153 silicon-carbon composite material Substances 0.000 description 3
- UDGKZGLPXCRRAM-UHFFFAOYSA-N 1,2,5-thiadiazole Chemical compound C=1C=NSN=1 UDGKZGLPXCRRAM-UHFFFAOYSA-N 0.000 description 2
- WGHQVHRXJVGVLU-UHFFFAOYSA-N 3,4-dichloro-1,2,5-thiadiazole 1,1-dioxide Chemical compound ClC1=NS(=O)(=O)N=C1Cl WGHQVHRXJVGVLU-UHFFFAOYSA-N 0.000 description 2
- WZMXSPCYRSRMJT-UHFFFAOYSA-N 3,4-diethoxy-1,2,5-thiadiazole 1,1-dioxide Chemical compound CCOC1=NS(=O)(=O)N=C1OCC WZMXSPCYRSRMJT-UHFFFAOYSA-N 0.000 description 2
- ZRSLQBDTGLCFJJ-UHFFFAOYSA-N 3,4-dimethoxy-1,2,5-thiadiazole 1,1-dioxide Chemical compound COC1=NS(=O)(=O)N=C1OC ZRSLQBDTGLCFJJ-UHFFFAOYSA-N 0.000 description 2
- UTJZCGUIPNKYSJ-UHFFFAOYSA-N 3-ethoxy-4-methoxy-1,2,5-thiadiazole 1,1-dioxide Chemical compound CCOC1=NS(=O)(=O)N=C1OC UTJZCGUIPNKYSJ-UHFFFAOYSA-N 0.000 description 2
- BJWMSGRKJIOCNR-UHFFFAOYSA-N 4-ethenyl-1,3-dioxolan-2-one Chemical compound C=CC1COC(=O)O1 BJWMSGRKJIOCNR-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000002041 carbon nanotube Substances 0.000 description 2
- 229910021393 carbon nanotube Inorganic materials 0.000 description 2
- 239000001768 carboxy methyl cellulose Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000002484 cyclic voltammetry Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 125000000623 heterocyclic group Chemical group 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 239000012046 mixed solvent Substances 0.000 description 2
- 239000005486 organic electrolyte Substances 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 2
- 239000010452 phosphate Substances 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 239000002210 silicon-based material Substances 0.000 description 2
- 239000007784 solid electrolyte Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 150000004867 thiadiazoles Chemical class 0.000 description 2
- CAAMSDWKXXPUJR-UHFFFAOYSA-N 3,5-dihydro-4H-imidazol-4-one Chemical compound O=C1CNC=N1 CAAMSDWKXXPUJR-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000002000 Electrolyte additive Substances 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- 229910013825 LiNi0.33Co0.33Mn0.33O2 Inorganic materials 0.000 description 1
- 229910012516 LiNi0.4Co0.2Mn0.4O2 Inorganic materials 0.000 description 1
- 229910002991 LiNi0.5Co0.2Mn0.3O2 Inorganic materials 0.000 description 1
- 229910011328 LiNi0.6Co0.2Mn0.2O2 Inorganic materials 0.000 description 1
- 229910015872 LiNi0.8Co0.1Mn0.1O2 Inorganic materials 0.000 description 1
- 229910013872 LiPF Inorganic materials 0.000 description 1
- 229910001228 Li[Ni1/3Co1/3Mn1/3]O2 (NCM 111) Inorganic materials 0.000 description 1
- 101150058243 Lipf gene Proteins 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 1
- KFDQGLPGKXUTMZ-UHFFFAOYSA-N [Mn].[Co].[Ni] Chemical compound [Mn].[Co].[Ni] KFDQGLPGKXUTMZ-UHFFFAOYSA-N 0.000 description 1
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical compound [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 125000003342 alkenyl group Chemical group 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 125000000304 alkynyl group Chemical group 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 125000002897 diene group Chemical group 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- RBBXSUBZFUWCAV-UHFFFAOYSA-N ethenyl hydrogen sulfite Chemical compound OS(=O)OC=C RBBXSUBZFUWCAV-UHFFFAOYSA-N 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- YAMHXTCMCPHKLN-UHFFFAOYSA-N imidazolidin-2-one Chemical compound O=C1NCCN1 YAMHXTCMCPHKLN-UHFFFAOYSA-N 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000016507 interphase Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000003446 memory effect Effects 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 description 1
- 229920001027 sodium carboxymethylcellulose Polymers 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0567—Liquid materials characterised by the additives
-
- 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
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- 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
- H01M10/058—Construction or manufacture
-
- 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
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
-
- 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
- H01M2220/00—Batteries for particular applications
- H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
-
- 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)
- Engineering & Computer Science (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Physics & Mathematics (AREA)
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The application discloses electrolyte, negative pole, lithium ion battery and vehicle. The electrolyte includes: lithium salts, organic solvents, and additives; the additive comprises a first additive, the first additive is a thiadiazole compound, and the thiadiazole compound has the following structural formula:wherein R is 1 And R 2 Are respectively selected from hydrogen atom, halogen atom, ether group, amino group and C 1 ‑C 10 Alkyl radical, C 2 ‑C 10 Alkenyl radical, C 2 ‑C 10 Alkynyl, C 3 ‑C 10 Cycloalkyl and C 2 ‑C 8 At least one nitrogen-containing polycyclic ring; c 1 ‑C 10 Alkyl radical, C 2 ‑C 10 Alkenyl radical, C 2 ‑C 10 Alkynyl, C 3 ‑C 10 Cycloalkyl and C 2 ‑C 8 The hydrogen atoms in the nitrogen-containing polycyclic ring may be partially or fully substituted with a substituent. The electrolyte has higher reduction potential, an SEI film is preferentially formed on a negative electrode, and the formed SEI film has better elasticity, so that the performance of the battery is favorably improved.
Description
Technical Field
The invention relates to the field of new energy, in particular to an electrolyte, a negative electrode, a lithium ion battery and a vehicle.
Background
The lithium ion battery has the advantages of high working voltage, large specific capacity, long cycle life, no memory effect, environmental friendliness and the like, and is widely applied to electronic products such as communication tools, notebook computers and the like. With the application of the lithium ion battery in electric vehicles and hybrid electric vehicles, people have higher requirements on the specific capacity of the lithium ion battery, and the silicon-carbon composite material relieves the problem of silicon volume expansion to a certain extent, so that the problems of capacity attenuation and electrode structure damage of the battery are solved.
However, the cycle performance of the battery has a close relationship with the formation, morphology, and structure of an SEI film (solid electrolyte interface film). In order to ensure that a good and stable SEI film is formed on the surface of a silicon-carbon composite negative electrode, a negative electrode film-forming additive is added into a conventional electrolyte system, the most frequently used and most effective electrolyte additive is fluoroethylene carbonate (FEC), but the FEC is easily decomposed at high temperature to generate hydrofluoric acid, so that the decomposition of lithium salt and a solvent is initiated, a large amount of gas is generated, the components of the electrolyte are changed, and the performance of a battery is reduced.
Disclosure of Invention
In view of the above-described drawbacks or deficiencies in the prior art, it is desirable to provide an electrolyte, a negative electrode, a lithium ion battery, and a vehicle.
In a first aspect, the present invention provides an electrolyte comprising: lithium salts, organic solvents, and additives;
the additive comprises a first additive, wherein the first additive is a thiadiazole compound, and the thiadiazole compound has the following structural formula:
wherein R is 1 And R 2 Are respectively selected from hydrogen atom, halogen atom, ether group, amino group and C 1 -C 10 Alkyl radical, C 2 -C 10 Alkenyl radical, C 2 -C 10 Alkynyl, C 3 -C 10 Cycloalkyl and C 2 -C 8 At least one nitrogen-containing polycyclic ring;
C 1 -C 10 alkyl radical, C 2 -C 10 Alkenyl radical, C 2 -C 10 Alkynyl, C 3 -C 10 Cycloalkyl and C 2 -C 8 The hydrogen atoms in the nitrogen-containing polycyclic ring may be partially or fully substituted with a substituent.
Alternatively, the substituent includes at least one of a halogen atom, a cyano group, a carboxyl group, and a sulfonic acid group.
The thiadiazole compound is selected from at least one of the following compounds:
as an optional scheme, the mass fraction of the first additive is 0.1-10% based on the total mass of the electrolyte.
As an optional scheme, the mass fraction of the first additive is 0.5% -5% based on the total mass of the electrolyte.
As an option, the additive further comprises: and a second additive, wherein the second additive is at least one selected from vinylene carbonate, fluoro-carbonate, di-fluoro-ethylene carbonate, ethylene sulfite, methylene methanedisulfonate, 1, 3-propane sultone, 1, 3-propylene sultone, vinyl sulfate, lithium difluorophosphate, lithium difluorobis (oxalato) phosphate and lithium tetrafluoro (oxalato) phosphate.
Optionally, the lithium salt is selected from at least one of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium bis fluorooxalato borate, lithium bis (trifluoromethylsulfonyl) imide and lithium bis fluorosulfonyl imide.
Alternatively, the organic solvent is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propyl methyl carbonate, γ -butyrolactone, methyl formate, ethyl acetate, methyl acetate, propyl acetate, butyl acetate, ethyl propionate, propyl propionate, and butyl propionate.
Optionally, the organic solvent is ethylene carbonate and ethyl methyl carbonate, and the mass ratio of the ethylene carbonate to the ethyl methyl carbonate is 1 (1-3).
In a second aspect, the present invention provides a negative electrode of a lithium ion battery, including a negative electrode current collector and a negative electrode active material layer located on a surface of the negative electrode current collector, where a surface of the negative electrode active material layer has an interface protective film, and the interface protective film is obtained by the electrolyte formation according to the first aspect.
In a third aspect, the present invention provides a lithium ion battery comprising: the electrolyte according to the first aspect and/or the negative electrode according to the second aspect.
In a fourth aspect, the present invention provides a vehicle, comprising: the lithium ion battery of the third aspect.
The electrolyte provided by the application comprises a first additive, wherein the first additive comprises a thiadiazole compound, the thiadiazole compound has a higher reduction potential, and a five-membered ring of a carbon-nitrogen diene structure of the thiadiazole compound is beneficial to generating a polymer SEI film on the surface of a negative electrode through electroreduction polymerization, so that the SEI film has good elasticity, is suitable for the volume change of silicon in a silicon-carbon negative electrode in the charge and discharge process of a battery, and improves the cycle performance of the battery; meanwhile, in the polymerization process of the thiadiazole compound, the lone electron pair of the nitrogen atom and the carbon-carbon double bond form a delocalized large pi bond, which is beneficial to improving the conductivity of the SEI film and further improving the performance of the battery; and high-temperature storage experiments prove that the high-temperature-resistant and low-temperature-resistant FEC battery has better high-temperature stability compared with the existing FEC battery, and is beneficial to improving the high-temperature performance of the battery.
Drawings
Fig. 1 is the reduction potential test results of example 1 and comparative example 1.
Detailed Description
The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention.
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail with reference to examples.
In a first aspect, an embodiment of the present invention provides an electrolyte, including: lithium salts, organic solvents, and additives;
the additive comprises a first additive, the first additive is a thiadiazole compound, and the thiadiazole compound has the following structural formula:
wherein R is 1 And R 2 Are respectively selected from hydrogen atom, halogen atom, ether group, amino group and C 1 -C 10 Alkyl radical, C 2 -C 10 Alkenyl radical, C 2 -C 10 Alkynyl, C 3 -C 10 Cycloalkyl and C 2 -C 8 At least one nitrogen-containing polycyclic ring;
C 1 -C 10 alkyl radical, C 2 -C 10 Alkenyl radical, C 2 -C 10 Alkynyl, C 3 -C 10 Cycloalkyl and C 2 -C 8 The hydrogen atoms in the nitrogen-containing polycyclic ring may be partially or fully substituted with a substituent.
It should be noted that, in the following description,
the thiadiazole compound of the embodiment of the present invention may be used alone as an additive for an electrolyte, and may be used in combination with an existing additive, such as FEC.
The thiooxy double bond in the thiadiazole compound has a strong electron withdrawing ability, so that the lowest unoccupied orbital (LUMO) of the five-membered heterocyclic ring is reduced. According to the front line orbit theory, the lower LUMO energy level can enable molecules to have higher reduction potential, so that the thiadiazole compound can be reduced by electrons more easily obtained at the negative electrode of a lithium battery. Through cyclic voltammetry tests, as shown in fig. 1, the thiadiazolated compounds in the examples of the present application have a higher reduction potential than ethylene carbonate, indicating that the additives of the examples of the present application can undergo a reduction reaction on the surface of the silicon anode in preference to ethylene carbonate.
The thiadiazole compound contains a conjugated carbon-nitrogen diene structure, electrons can be captured on the surface of the silicon cathode to form free radicals, then polymerization reaction is carried out, an SEI film containing a polymer chain segment is formed, the polymer chain segment enables the SEI film to have good elastic performance, and the SEI film can bear the volume change of a silicon material without cracking, so that the continuous reduction reaction of electrolyte does not occur any more, and the consumption of the electrolyte and active lithium is prevented.
Due to the occurrence of electropolymerization reaction, the conjugated diene structure of the thiadiazole compound is destroyed, a new five-membered heterocyclic ring is formed in a polymer chain segment, and due to the existence of lone electron pairs on nitrogen atoms, a large pi bond delocalized on the whole five-membered ring is formed, so that lithium ions can be better transmitted in an SEI film, and the ionic conductivity of the SEI film is improved.
Wherein, C 1 -C 10 Alkyl radical, C 3 -C 10 Cycloalkyl radical, C 2 -C 10 Alkenyl radical, C 2 -C 10 Alkynyl, and C 2 -C 8 The number of carbon atoms in the nitrogen-containing multi-element ring is preferably 1-5, which is beneficial to reducing the space structure, forming a chain polymer by the thiadiazole compound and improving the elasticity of the SEI film;
C 1 -C 10 alkyl radical, C 3 -C 10 Cycloalkyl, C 2 -C 10 Alkenyl radical, C 2 -C 10 Alkynyl group and C 2 -C 8 The hydrogen atoms in the nitrogen-containing polycyclic ring may be partially or whollyThe lithium ion battery is substituted by substituent groups, so that the activity of alkyl, alkenyl, alkynyl, cycloalkyl or a nitrogen-containing polycyclic ring is further improved, an SEI (solid electrolyte interphase) film can be generated on the negative electrode of the lithium ion battery, a solvent is protected, the consumption of electrolyte and active lithium is reduced, and the performance of the battery is improved.
In summary, the electrolyte solution of the embodiment of the application includes the first additive, the first additive includes a thiadiazole compound, the thiadiazole compound has a high reduction potential, and a five-membered ring of a carbonitrideene structure of the thiadiazole compound is beneficial to electroreduction polymerization on the surface of a negative electrode to generate a polymer SEI film, so that the SEI film has good elasticity, and is adapted to volume change of silicon in the charge and discharge processes of a battery, and the cycle performance of the battery is improved; meanwhile, in the polymerization process of the thiadiazole compound, the lone electron pair of the nitrogen atom and a carbon-carbon double bond form a delocalized large pi bond, so that the conductivity of the SEI film is improved, the performance of the battery is further improved, and high-temperature storage experiments prove that the thiadiazole compound has better high-temperature stability compared with the existing FEC, and the high-temperature performance of the battery is improved.
Further, the substituent includes at least one of a halogen atom, a cyano group, a carboxyl group, and a sulfonic acid group. Wherein, the self bond energy of halogen atom, cyano, carboxyl and sulfonic group is high, so that the oxidation is not easy, and the consumption of electrolyte is reduced; and the cyano group also has stronger coordination capability, can be combined with active sites (such as high-valence metal ions, such as nickel) on the surface of the positive electrode, and plays a role in shielding the active ions on the surface of the positive electrode, thereby reducing the decomposition effect of the positive electrode on the electrolyte.
Preferably, the thiadiazole compound according to the embodiment of the present invention is selected from the group consisting of 1,2, 5-thiadiazole-1, 1-dioxide (structural formula shown in formula I, CAS number: 140651-41-8), 3-ethoxy-4-methoxy-1, 2, 5-thiadiazole-1, 1-dioxide (structural formula shown in formula II, CAS number: 1379185-66-6), 4-methoxy-N, N-dimethyl-1, 1-dioxy-1, 2, 5-thiadiazole-3-amine (structural formula shown in formula III, CAS number: 90103-63-2), 3, 4-dimethoxy-1, 2, 5-thiadiazole-1, 1-dioxide (structural formula shown in formula IV, CAS number: 55904-83-1), 3, 4-dichloro- [1,2,5] thiadiazole-1, 1-dioxide (structural formula shown in formula V, CAS number: 55904-85-3), 3, 4-diethoxy-1, 2, 5-thiadiazole-1, 1-dioxide (structural formula is shown in formula VI, CAS number: 55904-84-2):
in a practical manner, the mass fraction of the first additive is 0.1% to 10% based on the total mass of the electrolyte, for example: 0.1%, 0.5%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%. 8%, 9% and 10%. The mass fraction range of the embodiment is beneficial to forming an SEI film on a negative electrode, the SEI film has organic solvent insolubility and can stably exist in an organic electrolyte solution, and solvent molecules cannot pass through the passivation film, so that damage to an electrode material caused by co-embedding of the solvent molecules is effectively prevented, and the cycle performance and the service life of the electrode are greatly improved.
In a preferred embodiment, the mass fraction of the first additive is 0.5% to 5% based on the total mass of the electrolyte. The more preferable mass fraction of the first additive is 1%, and the mass range ensures that the electrolyte generates an SEI film at the negative electrode, avoids the excessive first additive from increasing the viscosity of the electrolyte, and ensures that the electrolyte has good conductivity.
As an implementable manner, the additive further comprises: and a second additive selected from at least one of Vinylene Carbonate (VC), fluoroethylene carbonate (FEC), vinylethylene carbonate (VEC), vinyl sulfite (ES), Methylene Methanedisulfonate (MMDS), 1,3 Propanesultone (PS), 1, 3-propene sultone (1,3-PST), Vinyl Sulfate (VS), Lithium Difluorophosphate (LD), Lithium Difluorobis (LDP), and Lithium Tetrafluoro (LTP).
The second additive in the electrolyte is mainly used for being matched with the first additive, an SEI film with low impedance and high stability is formed on a negative electrode, the SEI film is insoluble in an organic solvent and can stably exist in an organic electrolyte solution, and solvent molecules cannot pass through the SEI film, so that co-embedding of the solvent molecules can be effectively prevented, damage to an electrode material due to co-embedding of the solvent molecules is avoided, and the cycle performance and the service life of the electrode are greatly improved.
In an implementable manner, the lithium salt is selected from at least one of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium difluorooxalato borate, lithium bis (trifluoromethylsulfonyl) imide and lithium bis fluorosulfonyl imide. The lithium salt reduces the fluorine content, thereby reducing the generated hydrofluoric acid and being beneficial to improving the high-temperature performance of the electrolyte.
As a practical mode, the concentration of the lithium salt is 0.1mol/L to 1.2 mol/L. The concentration range of the embodiment of the application is beneficial to the moderate dielectric constant of the electrolyte and the effective conduction of lithium ions.
In an implementation manner, the organic solvent is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propyl methyl carbonate, γ -butyrolactone, methyl formate, ethyl acetate, methyl acetate, propyl acetate, butyl acetate, ethyl propionate, propyl propionate, and butyl propionate.
In a specific embodiment, the organic solvent is ethylene carbonate and ethyl methyl carbonate, and the mass ratio of the ethylene carbonate to the ethyl methyl carbonate is 1 (1-3). Preferably 3: 7. The cyclic ethylene carbonate has higher dielectric constant and high viscosity, and the linear ethyl methyl carbonate has low viscosity, so that when the cyclic ethylene carbonate and the linear ethyl methyl carbonate are used in a matching manner, the overall ionic conductivity of the electrolyte can be improved, and in addition, the cyclic ethylene carbonate can also participate in the negative electrode to form an SEI film, so that the side reaction of the negative electrode can be effectively prevented; the linear carbonate may also be dimethyl carbonate, diethyl carbonate or a mixture thereof.
In the electrolyte of the embodiment of the application, the thiadiazole compound has a high reduction potential, which is favorable for generating an SEI film on a negative electrode in preference to a solvent, and the five-membered ring of the carbonitridene structure of the thiadiazole compound is favorable for generating a polymer SEI film on the surface of the negative electrode through electroreduction polymerization, so that the SEI film has good elasticity and is suitable for the volume change of silicon in the charge and discharge processes of a battery; meanwhile, in the polymerization process of the thiadiazole compound, the lone electron pair of the nitrogen atom and the carbon-carbon double bond form a delocalized large pi bond, which is beneficial to improving the conductivity of the SEI film and further improving the performance of the battery;
and high-temperature storage experiments prove that the high-temperature-resistant and low-temperature-resistant FEC battery has better high-temperature stability compared with the existing FEC battery, and is beneficial to improving the high-temperature performance of the battery.
In a second aspect, an embodiment of the present invention provides a negative electrode of a lithium ion battery, where the negative electrode of the lithium ion battery includes a negative electrode current collector and a negative electrode active material layer located on a surface of the negative electrode current collector, and an interface protective film is provided on a surface of the negative electrode active material layer, where the interface protective film is obtained by formation of the electrolyte solution described in the first aspect. Thus, the negative electrode has all the features and advantages of the electrolyte described above, and thus, the description thereof is omitted.
In a third aspect, embodiments of the present invention provide a lithium ion battery. The lithium ion battery comprises the electrolyte of the first aspect and/or the negative electrode of the second aspect. Therefore, the lithium ion battery has all the features and advantages of the electrolyte and/or the negative electrode, and the description thereof is omitted. In general, the lithium ion battery has the advantage of being capable of having good high-temperature cycle performance.
The negative electrode of lithium batteries is mainly a silicon negative electrode, such as pure silicon, silicon oxide or a silicon carbon composite.
The positive electrode of the lithium battery may be a ternary nickel cobalt manganese material, for example, LiNi 0.33 Co 0.33 Mn 0.33 O 2 (NCM111 type), LiNi 0.4 Co 0.2 Mn 0.4 O 2 (NCM424 type), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523 type), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622 type), LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811 type).
In a fourth aspect, the present disclosure provides a vehicle including the lithium ion battery of the third aspect. For example, a plurality of battery packs composed of the lithium ion batteries described above may be included. Thus, the vehicle has all the features and advantages of the lithium ion battery described above, and the description thereof is omitted.
The present invention is illustrated below by way of specific examples, which are intended to be illustrative only and not to limit the scope of the present invention in any way, and reagents and materials used therein are commercially available, unless otherwise specified, and conditions or steps thereof are not specifically described.
The lithium ion batteries of examples 1 to 15 and comparative examples 1 to 4 were prepared as follows:
(1) preparing an electrolyte:
mixing ethylene carbonate and methyl ethyl carbonate into a mixed solvent according to the mass ratio of 3:7, and adding lithium hexafluorophosphate (LiPF) into the mixed solvent 6 ) And adding an additive into the electrolyte until the molar concentration is 1.0mol/L, and uniformly stirring to obtain the electrolyte.
(2) Preparing a positive plate:
uniformly mixing NCM, Carbon Nano Tube (CNT) and polyvinylidene fluoride (PVDF) in a mass ratio of 100:2:2 to obtain paste, uniformly coating the paste on an aluminum foil serving as a positive current collector, and drying in a vacuum oven at 60 ℃ for 24 hours to obtain the positive plate.
(3) Preparing a negative plate:
uniformly mixing a carbon-coated silicon material, a conductive agent super-p, a thickening agent sodium carboxymethyl cellulose (CMC) and a binder Styrene Butadiene Rubber (SBR) according to a mass ratio of 100:2:2:3, uniformly coating the obtained paste on a copper foil serving as a negative current collector, and drying for 24 hours in a vacuum oven at 60 ℃ to obtain the negative plate.
(4) Preparing a lithium ion battery:
preparing a soft package lithium battery with a silicon negative electrode of SL523450, preparing a bare cell from a positive plate, a negative plate and an isolating membrane by a winding process in an argon glove box with water and oxygen content less than 5ppm, filling the cell into an aluminum plastic membrane packaging shell, injecting the electrolyte, sequentially sealing, standing, carrying out hot and cold pressing, forming, capacity grading and the like, and thus obtaining the lithium ion battery P1.
Preparation of a CR2016 button cell: and (3) adopting the coated silicon negative electrode plate to the lithium plate, wherein the injection amount is about 100mg, and thus obtaining the battery for the reduction potential test of the electrolyte.
Wherein the formation process comprises the following steps: the simulation battery is charged to 1.5V by 45mA (0.05C) current and is kept at 1.5V for 10 hours, so that the battery pole piece is fully soaked by electrolyte; after sufficient aging, the cell was first charged with a small current of 9mA (C/100) for 15h to form a stable and complete SEI film, then charged to 4.2V with a current of 45mA (0.05C) and then discharged to 3V.
TABLE 1 concrete kinds and contents of additives in examples 1-15 and comparative examples 1-2
The structural formula of the 1,2, 5-thiadiazole (CAS number: 23091-39-6) is shown in the specification
The performance test process and test results of the lithium ion battery are described as follows:
(1) reduction potential test
The button cell batteries in the examples and the comparative examples are subjected to cyclic voltammetry, the scanning speed is 0.2mV/s, and the scanning range is 0.005-2.5V. The test equipment was an electrochemical workstation of chenhua model CHI 600C.
(2) High temperature storage test of electrolyte
The electrolytes of examples and comparative examples were sealed in square aluminum-plastic bags, respectively, stored in a 60 ℃ incubator for 7 days, and the volume expansion rates before and after the storage were calculated by size exclusion. The volume expansion (%) is the percentage of the volume after storage at high temperature divided by the volume before storage.
(3) Silicon negative electrode normal/high temperature battery cycle test and elasticity test of negative electrode surface SEI film after cycle
The pouch cells of examples and comparative examples (10 for each condition, the results were averaged) were cycled 400 times between 3.0V and 4.2V at room temperature (25 ℃) and elevated temperature of 60 ℃ respectively at 900mA (1C). The test instrument can be a domestic blue model CT2001C test cabinet, and the capacity retention rate is calculated. The capacity retention (%) was calculated as a percentage obtained by dividing the discharge capacity at the 150 th cycle by the initial discharge capacity at the first cycle.
After the completion of the cycle, the batteries of examples and comparative examples were disassembled, and the silicon negative electrode was cut to 1X 1cm 2 The Young's modulus of the pellets was measured by an atomic force microscope (AFM, Bruker Dimension Icon) probe method, and the elasticity of the SEI film on the surface of the negative electrode was measured by the Young's modulus, which indicates that the elasticity of the SEI film was better when the Young's modulus was small. Young's modulus calculation method F ═ (2/pi) (E/(1-v2)) δ 2tan (σ), where F is probe force, E is young's modulus, v is Poisson coefficient (here 0.5), δ is SEI film thickness, and σ is half cone tip apex angle. The method is publicly reported in the literature.
The results of the reduction potential test of the electrolytes of examples 1 to 15 and comparative examples 1 to 4 according to the procedure and method described above are shown in table 1:
TABLE 1 reduction potential test results of examples 1 to 15 and comparative examples 1 to 4
TABLE 2 high-temperature storage test results of electrolytes of examples 1 to 15 and comparative examples 1 to 4
Table 3 cycle test results of examples 1 to 15 and comparative examples 1 to 4 and elasticity test results of SEI film on surface of negative electrode after cycle
According to the results shown in table 1 and fig. 1:
in comparison with comparative examples 1 to 4, the additives of the electrolytes of examples 1 to 15 include thiadiazole compounds, each having a reduction potential higher than that of comparative examples 1 to 4; and the reduction potentials of examples 1-6, examples 8-12, and example 15 were all higher at 1.25-1.4V (vs. Li/Li) + ). Therefore, the additive of the embodiment of the invention can be reduced to form a film in preference to solvent molecules during the battery cycle process, and plays a role in protecting the electrolyte.
As can be seen from the reduction potentials of examples 1 and 15 and comparative example 2, the additive of the examples of the present invention can be used alone or in combination with an existing negative electrode film-forming additive (e.g., FEC); comparing the reduction potentials of example 15 and comparative example 2, the thiadiazole compound is advantageous for increasing the reduction potential of the electrolyte, and is further advantageous for preferentially reducing to form a film.
The reduction potential of example 1 is higher, the additive of example 1 is 1,2, 5-thiadiazole-1, 1-dioxide, the additive of comparative example 3 is imidazolinone (five-membered ring does not contain sulfur), and the additive of comparative example 4 is 1,2, 5-thiadiazole (five-membered ring does not contain sulfur oxygen double bond), compared to comparative examples 3 and 4. Therefore, sulfur in the additive in the embodiments of the present invention can lower the LUMO level of the molecule and increase the reduction potential, so that the molecule is more easily polymerized in the negative electrode of the battery.
According to the results shown in table 2:
compared to comparative examples 1-4, the electrolytes of the additives of examples 1-6 have much lower volume expansion rates at high temperatures than comparative examples 1-4. Therefore, it is demonstrated that the electrolyte solutions of examples 1-6 contain thiadiazole compounds at the same amount of additives, so that the electrolyte solutions can be stable at high temperature, generate little gas, and are beneficial to improving the performance of the battery.
The electrolytes of examples 1 to 12 have a lower volume expansion rate after storage at high temperature than those of examples 13 to 14, compared to examples 13 to 14. Therefore, the mass range of the thiadiazole compound in the electrolyte disclosed by the embodiment of the invention is in a range from 0.1% to 10%, which is beneficial to improving the high-temperature storage performance of the electrolyte.
According to the results shown in table 3:
as can be seen from the capacity retention rates of the batteries subjected to the cycle tests at 25 ℃ and 60 ℃ in table 3, the capacity retention rates of the silicon negative electrode batteries of examples 1 to 6 after 400 cycles are all higher than those of comparative examples 1 to 4, so that the additive thiadiazole compound in the embodiment of the invention is beneficial to improving the cycle performance of the batteries under the condition of the same additive amount; after 60 ℃ circulation, the capacity retention rate is over 50%, and the additive further improves the high-temperature circulation performance of the battery.
From the young's modulus results in table 3, it can be seen that the young's moduli of the silicon negative electrode batteries of examples 1 to 6 after the completion of the cycle were all lower than those of comparative examples 1 to 4, smaller young's moduli, thus indicating that the additives of the examples of the present invention have better elasticity in the SEI film formed on the negative electrode with the same amount of the additives. The possible reason for the analysis is that the additives of examples 1 to 6 facilitate the formation of an SEI film containing a polymer segment at the negative electrode, making the SEI film elastic, thereby improving the cycle performance of the silicon negative electrode battery.
In conclusion, the electrolyte has higher reduction potential, which is beneficial to preferentially forming an SEI film on the surface of a negative electrode, and the thiadiazole compound in the electrolyte enables the SEI film to have good elasticity, so that the electrolyte is suitable for the volume change of silicon in the charge and discharge process of a battery, and the cycle performance of the battery is improved; in addition, compared with the existing FEC, the electrolyte has better high-temperature stability, and is beneficial to improving the high-temperature performance of the battery.
The foregoing description is only exemplary of the preferred embodiments of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention according to the present application is not limited to the specific combination of the above-mentioned features, but also covers other embodiments where any combination of the above-mentioned features or their equivalents is made without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.
Claims (12)
1. An electrolyte, comprising: lithium salts, organic solvents, and additives;
the additive comprises a first additive, wherein the first additive is a thiadiazole compound, and the thiadiazole compound has a structural formula as follows:
wherein R is 1 And R 2 Are respectively selected from hydrogen atom, halogen atom, ether group, amino group and C 1 -C 10 Alkyl radical, C 2 -C 10 Alkenyl radical, C 2 -C 10 Alkynyl, C 3 -C 10 Cycloalkyl and C 2 -C 8 At least one nitrogen-containing polycyclic ring;
said C is 1 -C 10 Alkyl radical, said C 2 -C 10 Alkenyl radical, said C 2 -C 10 Alkynyl, said C 3 -C 10 Cycloalkyl and said C 2 -C 8 The hydrogen atoms in the nitrogen-containing polycyclic ring may be partially or fully substituted with a substituent.
2. The electrolyte of claim 1, wherein the substituent comprises at least one of a halogen atom, a cyano group, a carboxyl group, and a sulfonic acid group.
4. the electrolyte of claim 1, wherein the mass fraction of the first additive is 0.1% to 10% based on the total mass of the electrolyte.
5. The electrolyte of claim 4, wherein the first additive is present in an amount of 0.5% to 5% by mass, based on the total mass of the electrolyte.
6. The electrolyte of any one of claims 1-5, wherein the additive further comprises a second additive selected from at least one of vinylene carbonate, fluoro-carbonate, di-fluoro-ethylene carbonate, ethylene carbonate, ethylene sulfite, methylene methanedisulfonate, 1, 3-propane sultone, 1, 3-propene sultone, vinyl sulfate, lithium difluorophosphate, lithium difluorobis-oxalate, lithium tetrafluorooxalate phosphate.
7. The electrolyte of any one of claims 1-5, wherein the lithium salt is selected from at least one of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium bis fluorooxalato borate, lithium bis (trifluoromethylsulfonyl) imide, and lithium bis fluorosulfonyl imide.
8. The electrolyte of any one of claims 1-5, wherein the organic solvent is selected from at least one of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propyl methyl carbonate, γ -butyrolactone, methyl formate, ethyl acetate, methyl acetate, propyl acetate, butyl acetate, ethyl propionate, propyl propionate, and butyl propionate.
9. The electrolyte according to claim 8, wherein the organic solvent is ethylene carbonate and ethyl methyl carbonate, and the mass ratio of the ethylene carbonate to the ethyl methyl carbonate is 1 (1-3).
10. The negative electrode of the lithium ion battery is characterized by comprising a negative electrode current collector and a negative electrode active material layer positioned on the surface of the negative electrode current collector, wherein the surface of the negative electrode active material layer is provided with an interface protective film, and the interface protective film is obtained by the formation of the electrolyte according to any one of claims 1 to 9.
11. A lithium ion battery, comprising: the electrolyte of any one of claims 1 to 9 and/or the negative electrode of claim 10.
12. A vehicle comprising the lithium ion battery of claim 11.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110224657.6A CN115000514A (en) | 2021-03-01 | 2021-03-01 | Electrolyte, negative electrode, lithium ion battery and vehicle |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110224657.6A CN115000514A (en) | 2021-03-01 | 2021-03-01 | Electrolyte, negative electrode, lithium ion battery and vehicle |
Publications (1)
Publication Number | Publication Date |
---|---|
CN115000514A true CN115000514A (en) | 2022-09-02 |
Family
ID=83018118
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202110224657.6A Pending CN115000514A (en) | 2021-03-01 | 2021-03-01 | Electrolyte, negative electrode, lithium ion battery and vehicle |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN115000514A (en) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007172990A (en) * | 2005-12-21 | 2007-07-05 | Sony Corp | Electrolyte and battery |
CN102856586A (en) * | 2011-06-28 | 2013-01-02 | 夏普株式会社 | Nonaqueous secondary battery and flame retardant for use in the same |
KR20140022348A (en) * | 2012-08-14 | 2014-02-24 | 솔브레인 주식회사 | Electrolyte and lithium secondary battery comprising the same |
CN111883828A (en) * | 2020-07-24 | 2020-11-03 | 香河昆仑化学制品有限公司 | Non-aqueous electrolyte of lithium ion battery and lithium ion battery |
-
2021
- 2021-03-01 CN CN202110224657.6A patent/CN115000514A/en active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007172990A (en) * | 2005-12-21 | 2007-07-05 | Sony Corp | Electrolyte and battery |
CN102856586A (en) * | 2011-06-28 | 2013-01-02 | 夏普株式会社 | Nonaqueous secondary battery and flame retardant for use in the same |
KR20140022348A (en) * | 2012-08-14 | 2014-02-24 | 솔브레인 주식회사 | Electrolyte and lithium secondary battery comprising the same |
CN111883828A (en) * | 2020-07-24 | 2020-11-03 | 香河昆仑化学制品有限公司 | Non-aqueous electrolyte of lithium ion battery and lithium ion battery |
Non-Patent Citations (1)
Title |
---|
MIRIFICO, MV: "ELECTROREDUCTION OF 3, 4-DIPHENYL-1, 2, 5-THIADIAZOLE-1, 1-DIOXIDE IN ACETONITRILE SOLUTION AND REACTIONS WITH PROTON DONORS", 《ELECTROCHIMICA ACTA》, vol. 36, no. 1, 31 December 1991 (1991-12-31), pages 167 - 171, XP026506371, DOI: 10.1016/0013-4686(91)85197-F * |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN109873206B (en) | Lithium ion battery electrolyte and lithium ion battery | |
CN109818064B (en) | High-temperature high-voltage non-aqueous electrolyte and lithium ion battery containing same | |
CN109216759B (en) | Lithium ion battery electrolyte and lithium ion battery | |
CN111883839B (en) | High-voltage electrolyte and lithium ion battery based on same | |
KR20220062105A (en) | Additives for battery electrolytes, lithium ion battery electrolytes and lithium ion batteries | |
CN111525190B (en) | Electrolyte and lithium ion battery | |
CN113078356B (en) | High-voltage lithium cobalt oxide lithium ion battery non-aqueous electrolyte and lithium ion battery | |
CN108736065B (en) | Electrolyte and lithium ion battery containing electrolyte and/or anode | |
CN111755746B (en) | Lithium ion battery electrolyte and lithium ion battery | |
WO2023040119A1 (en) | Electrolyte additive, electrolyte containing same, and lithium-ion battery | |
CN108987802B (en) | Non-aqueous electrolyte for high-voltage lithium ion battery | |
WO2023020314A1 (en) | Non-aqueous electrolyte solution and lithium battery | |
CN113130990A (en) | Electrolyte and secondary battery using same | |
CN109473717B (en) | Electrolyte suitable for high-voltage high-nickel power battery and high-voltage high-nickel power battery | |
WO2023045164A1 (en) | Non-aqueous electrolyte and lithium-ion battery thereof | |
CN110957528A (en) | Additive for battery electrolyte, lithium ion battery electrolyte and lithium ion battery | |
CN112349963B (en) | Electrolyte containing silicon solvent and mono-alkane lithium sulfate salt and lithium ion battery | |
CN110492177B (en) | Additive for battery electrolyte, lithium ion battery electrolyte and lithium ion battery | |
CN112713307A (en) | High-voltage non-aqueous electrolyte and lithium ion battery based on same | |
CN117219859A (en) | Lithium ion battery electrolyte, preparation method and application | |
CN111129589A (en) | Ternary high-voltage lithium ion battery non-aqueous electrolyte and lithium ion battery thereof | |
CN113871712B (en) | Lithium ion battery electrolyte, preparation method thereof and lithium ion battery | |
CN114927758A (en) | Electrolyte for improving high-temperature performance of lithium ion battery and lithium ion battery | |
CN115000514A (en) | Electrolyte, negative electrode, lithium ion battery and vehicle | |
CN114583265B (en) | Electrolyte, positive electrode, lithium ion battery and vehicle |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination |