CN111668544B - Electrolyte and lithium ion battery - Google Patents
Electrolyte and lithium ion battery Download PDFInfo
- Publication number
- CN111668544B CN111668544B CN202010542103.6A CN202010542103A CN111668544B CN 111668544 B CN111668544 B CN 111668544B CN 202010542103 A CN202010542103 A CN 202010542103A CN 111668544 B CN111668544 B CN 111668544B
- Authority
- CN
- China
- Prior art keywords
- thione
- electrolyte
- bis
- trimethylsilyl
- imidazole
- 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.)
- Active
Links
- 239000003792 electrolyte Substances 0.000 title claims abstract description 129
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 93
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 93
- 239000000654 additive Substances 0.000 claims abstract description 70
- 230000000996 additive effect Effects 0.000 claims abstract description 61
- 239000003960 organic solvent Substances 0.000 claims abstract description 26
- 229910003002 lithium salt Inorganic materials 0.000 claims abstract description 14
- 159000000002 lithium salts Chemical class 0.000 claims abstract description 14
- 125000004432 carbon atom Chemical group C* 0.000 claims abstract description 12
- 125000000217 alkyl group Chemical group 0.000 claims abstract description 8
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 claims abstract description 5
- 125000003342 alkenyl group Chemical group 0.000 claims abstract description 4
- 229910052736 halogen Inorganic materials 0.000 claims abstract description 4
- 150000002367 halogens Chemical class 0.000 claims abstract description 4
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 4
- 239000001257 hydrogen Substances 0.000 claims abstract description 4
- 125000004435 hydrogen atom Chemical class [H]* 0.000 claims abstract description 4
- 150000005678 chain carbonates Chemical class 0.000 claims description 7
- 150000005676 cyclic carbonates Chemical class 0.000 claims description 7
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 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
- BJWMSGRKJIOCNR-UHFFFAOYSA-N 4-ethenyl-1,3-dioxolan-2-one Chemical compound C=CC1COC(=O)O1 BJWMSGRKJIOCNR-UHFFFAOYSA-N 0.000 claims description 4
- 229910001290 LiPF6 Inorganic materials 0.000 claims description 4
- XNENYPKLNXFICU-UHFFFAOYSA-N P(O)(O)O.C[SiH](C)C.C[SiH](C)C.C[SiH](C)C Chemical compound P(O)(O)O.C[SiH](C)C.C[SiH](C)C.C[SiH](C)C XNENYPKLNXFICU-UHFFFAOYSA-N 0.000 claims description 4
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 claims description 4
- FDPIMTJIUBPUKL-UHFFFAOYSA-N pentan-3-one Chemical compound CCC(=O)CC FDPIMTJIUBPUKL-UHFFFAOYSA-N 0.000 claims description 4
- AJXUZUOATLZSRT-UHFFFAOYSA-N 1,3-bis(trimethylsilyl)imidazole-2-thione Chemical compound C[Si](N1C(N(C=C1)[Si](C)(C)C)=S)(C)C AJXUZUOATLZSRT-UHFFFAOYSA-N 0.000 claims description 3
- KLLQVNFCMHPYGL-UHFFFAOYSA-N 5h-oxathiole 2,2-dioxide Chemical compound O=S1(=O)OCC=C1 KLLQVNFCMHPYGL-UHFFFAOYSA-N 0.000 claims description 3
- PHYXJKPGADCDBV-UHFFFAOYSA-N CC(C)C(N(C1=S)[Si](C)(C)C)=C(C(C)C)N1[Si](C)(C)C Chemical compound CC(C)C(N(C1=S)[Si](C)(C)C)=C(C(C)C)N1[Si](C)(C)C PHYXJKPGADCDBV-UHFFFAOYSA-N 0.000 claims description 3
- VJRDDKXJDILTMJ-UHFFFAOYSA-N CC(C)C(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C Chemical compound CC(C)C(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C VJRDDKXJDILTMJ-UHFFFAOYSA-N 0.000 claims description 3
- HJCYSGWMNZCLIC-UHFFFAOYSA-N CC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C Chemical compound CC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C HJCYSGWMNZCLIC-UHFFFAOYSA-N 0.000 claims description 3
- NHCRGQCNPRNNGQ-UHFFFAOYSA-N CC=CC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C Chemical compound CC=CC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C NHCRGQCNPRNNGQ-UHFFFAOYSA-N 0.000 claims description 3
- IWEKTJAFPWINBZ-UHFFFAOYSA-N CCC(N(C1=S)[Si](C)(C)C)=C(CC)N1[Si](C)(C)C Chemical compound CCC(N(C1=S)[Si](C)(C)C)=C(CC)N1[Si](C)(C)C IWEKTJAFPWINBZ-UHFFFAOYSA-N 0.000 claims description 3
- FAIOLECAEKYAOT-UHFFFAOYSA-N CCC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C Chemical compound CCC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C FAIOLECAEKYAOT-UHFFFAOYSA-N 0.000 claims description 3
- PBOPHSYMIODDQM-UHFFFAOYSA-N CCCC(N(C1=S)[Si](C)(C)C)=C(CCC)N1[Si](C)(C)C Chemical compound CCCC(N(C1=S)[Si](C)(C)C)=C(CCC)N1[Si](C)(C)C PBOPHSYMIODDQM-UHFFFAOYSA-N 0.000 claims description 3
- HLXBHGAIMKULFA-UHFFFAOYSA-N CCCC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C Chemical compound CCCC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C HLXBHGAIMKULFA-UHFFFAOYSA-N 0.000 claims description 3
- UAWDEOXTOKVAKU-UHFFFAOYSA-N CCCCC(N(C1=S)[Si](C)(C)C)=C(CCCC)N1[Si](C)(C)C Chemical compound CCCCC(N(C1=S)[Si](C)(C)C)=C(CCCC)N1[Si](C)(C)C UAWDEOXTOKVAKU-UHFFFAOYSA-N 0.000 claims description 3
- NTSYDEWVGWDCBS-UHFFFAOYSA-N CCCCC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C Chemical compound CCCCC(N(C1=S)[Si](C)(C)C)=CN1[Si](C)(C)C NTSYDEWVGWDCBS-UHFFFAOYSA-N 0.000 claims description 3
- LDRBIUBGSUISIL-UHFFFAOYSA-N C[Si](C)(C)N(C(C(Cl)(Cl)Cl)=C(C(Cl)(Cl)Cl)N1[Si](C)(C)C)C1=S Chemical compound C[Si](C)(C)N(C(C(Cl)(Cl)Cl)=C(C(Cl)(Cl)Cl)N1[Si](C)(C)C)C1=S LDRBIUBGSUISIL-UHFFFAOYSA-N 0.000 claims description 3
- NMLYADLCMFLPNL-UHFFFAOYSA-N C[Si](C)(C)N(C(C(F)(F)F)=C(C(F)(F)F)N1[Si](C)(C)C)C1=S Chemical compound C[Si](C)(C)N(C(C(F)(F)F)=C(C(F)(F)F)N1[Si](C)(C)C)C1=S NMLYADLCMFLPNL-UHFFFAOYSA-N 0.000 claims description 3
- HDNATZSLWXDINK-UHFFFAOYSA-N C[Si](C)(C)N(C=C(C(F)(F)F)N1[Si](C)(C)C)C1=S Chemical compound C[Si](C)(C)N(C=C(C(F)(F)F)N1[Si](C)(C)C)C1=S HDNATZSLWXDINK-UHFFFAOYSA-N 0.000 claims description 3
- FUSPBPOTOAFCAY-UHFFFAOYSA-N C[Si](C)(C)N(C=C(C1=CC=CC=C1)N1[Si](C)(C)C)C1=S Chemical compound C[Si](C)(C)N(C=C(C1=CC=CC=C1)N1[Si](C)(C)C)C1=S FUSPBPOTOAFCAY-UHFFFAOYSA-N 0.000 claims description 3
- CQCVFTRUAHJJFW-UHFFFAOYSA-N C[Si](C)(C)N(C=C(C=C)N1[Si](C)(C)C)C1=S Chemical compound C[Si](C)(C)N(C=C(C=C)N1[Si](C)(C)C)C1=S CQCVFTRUAHJJFW-UHFFFAOYSA-N 0.000 claims description 3
- SPUMWPNUMLWFPX-UHFFFAOYSA-N C[Si](C)(C)N(C=C(N1[Si](C)(C)C)Cl)C1=S Chemical compound C[Si](C)(C)N(C=C(N1[Si](C)(C)C)Cl)C1=S SPUMWPNUMLWFPX-UHFFFAOYSA-N 0.000 claims description 3
- KKBPSNQNTSGRCO-UHFFFAOYSA-N C[Si](C)(C)N(C=C(N1[Si](C)(C)C)F)C1=S Chemical compound C[Si](C)(C)N(C=C(N1[Si](C)(C)C)F)C1=S KKBPSNQNTSGRCO-UHFFFAOYSA-N 0.000 claims description 3
- PSGVDOBEZPYZJK-UHFFFAOYSA-N C[Si](N1C(N(C(=C1C)C)[Si](C)(C)C)=S)(C)C Chemical compound C[Si](N1C(N(C(=C1C)C)[Si](C)(C)C)=S)(C)C PSGVDOBEZPYZJK-UHFFFAOYSA-N 0.000 claims description 3
- 229910013188 LiBOB Inorganic materials 0.000 claims description 3
- 229910000552 LiCF3SO3 Inorganic materials 0.000 claims description 3
- 229910021447 LiN(CxF2x+1SO2)(CyF2y+1SO2) Inorganic materials 0.000 claims description 3
- 229910012265 LiPO2F2 Inorganic materials 0.000 claims description 3
- 229910001540 lithium hexafluoroarsenate(V) Inorganic materials 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
- 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
- ZRZFJYHYRSRUQV-UHFFFAOYSA-N phosphoric acid trimethylsilane Chemical compound C[SiH](C)C.C[SiH](C)C.C[SiH](C)C.OP(O)(O)=O ZRZFJYHYRSRUQV-UHFFFAOYSA-N 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 2
- 229940032007 methylethyl ketone Drugs 0.000 claims description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 abstract description 52
- 239000007789 gas Substances 0.000 abstract description 11
- 230000010220 ion permeability Effects 0.000 abstract description 6
- 238000004519 manufacturing process Methods 0.000 abstract description 6
- 230000000052 comparative effect Effects 0.000 description 26
- 238000012360 testing method Methods 0.000 description 16
- 230000000694 effects Effects 0.000 description 15
- 238000011056 performance test Methods 0.000 description 14
- 125000000026 trimethylsilyl group Chemical group [H]C([H])([H])[Si]([*])(C([H])([H])[H])C([H])([H])[H] 0.000 description 14
- 239000011203 carbon fibre reinforced carbon Substances 0.000 description 12
- 239000007774 positive electrode material Substances 0.000 description 10
- 239000007773 negative electrode material Substances 0.000 description 9
- 239000006258 conductive agent Substances 0.000 description 8
- 230000009286 beneficial effect Effects 0.000 description 7
- 238000007086 side reaction Methods 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 125000000623 heterocyclic group Chemical group 0.000 description 6
- 230000002401 inhibitory effect Effects 0.000 description 6
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 5
- 230000035699 permeability Effects 0.000 description 5
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 4
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 4
- 239000006230 acetylene black Substances 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 239000011230 binding agent Substances 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000011883 electrode binding agent Substances 0.000 description 4
- 230000006872 improvement Effects 0.000 description 4
- 230000005764 inhibitory process Effects 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 3
- 239000002033 PVDF binder Substances 0.000 description 3
- 239000001768 carboxy methyl cellulose Substances 0.000 description 3
- 239000002270 dispersing agent Substances 0.000 description 3
- 229910052744 lithium Inorganic materials 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000004448 titration Methods 0.000 description 3
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 description 2
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 2
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 2
- 239000011889 copper foil Substances 0.000 description 2
- 239000008151 electrolyte solution Substances 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 125000004433 nitrogen atom Chemical group N* 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 2
- 229920003048 styrene butadiene rubber Polymers 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- ZPFAVCIQZKRBGF-UHFFFAOYSA-N 1,3,2-dioxathiolane 2,2-dioxide Chemical compound O=S1(=O)OCCO1 ZPFAVCIQZKRBGF-UHFFFAOYSA-N 0.000 description 1
- DCERHCFNWRGHLK-UHFFFAOYSA-N C[Si](C)C Chemical compound C[Si](C)C DCERHCFNWRGHLK-UHFFFAOYSA-N 0.000 description 1
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 1
- 229910013426 LiN(SO2F)2 Inorganic materials 0.000 description 1
- 229910013716 LiNi Inorganic materials 0.000 description 1
- 229910013872 LiPF Inorganic materials 0.000 description 1
- 101150058243 Lipf gene Proteins 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229910000676 Si alloy Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- HFCVPDYCRZVZDF-UHFFFAOYSA-N [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O Chemical compound [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O HFCVPDYCRZVZDF-UHFFFAOYSA-N 0.000 description 1
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical group [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005524 ceramic coating Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 239000013538 functional additive Substances 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- -1 lithium hexafluorophosphate Chemical compound 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
- 239000000463 material Substances 0.000 description 1
- 230000003446 memory effect Effects 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 description 1
- 229920001027 sodium carboxymethylcellulose Polymers 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 125000002023 trifluoromethyl group Chemical group FC(F)(F)* 0.000 description 1
- PQDJYEQOELDLCP-UHFFFAOYSA-N trimethylsilane Chemical compound C[SiH](C)C PQDJYEQOELDLCP-UHFFFAOYSA-N 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
- 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
- H01M10/42—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
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
-
- 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)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Secondary Cells (AREA)
Abstract
The invention relates to the technical field of lithium ion batteries, and particularly provides an electrolyte and a lithium ion battery. The electrolyte contains lithium salt and organic solvent; the electrolyte also contains an additive shown as a formula (I) in the specification, wherein R1、R2Independently selected from any one of hydrogen, alkyl with 1-20 carbon atoms, halogenated alkyl with 1-20 carbon atoms, phenyl, alkenyl with 1-20 carbon atoms and halogen. In the electrolyte, the additive shown in the formula (I) is added, so that the additive can effectively inhibit the content of hydrofluoric acid in the electrolyte, a compact and stable SEI film with good lithium ion permeability can be formed on the surface of a negative electrode in a lithium ion battery, and the whole lithium ion battery has low impedance, good cycle performance and good high-temperature gas production performance.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to an electrolyte and a lithium ion battery.
Background
Lithium ion batteries are widely used in electronic products due to their high specific energy, no memory effect, small size, light weight, short charging time, long cycle life, and the like. However, with the continuous development of the technology, users have made higher requirements on the cycle performance, the rapid charging and discharging capability and the environmental suitability of the lithium battery, and the impedance of the lithium battery is an important index for determining whether the above performance is excellent or not.
Generally, functional additives are added into electrolyte of the lithium ion battery, and SEI film components are adjusted to be more beneficial to lithium ion permeation, so that the impedance of the lithium ion battery can be effectively reduced, and the cycle performance of the lithium ion battery is improved. However, since lithium hexafluorophosphate is used as an electrolyte in the electrolyte of the lithium ion battery, hydrofluoric acid is inevitably introduced into the lithium ion battery. In the process of storage and use, the content of hydrofluoric acid in the electrolyte is increased, and when the content of hydrofluoric acid in the lithium ion battery exceeds a certain concentration, active lithium ions on the surface of a negative electrode are consumed, and a positive electrode material is corroded, so that the impedance of the lithium ion battery is increased, the cycle performance is reduced, and the like.
In view of the above, it is necessary to add a component capable of consuming hydrofluoric acid to the electrolyte or develop a new electrolyte to suppress the HF content in the electrolyte, and the added component or the developed new electrolyte preferably forms a stable SEI film on the surface of the electrode, which is advantageous for permeation of lithium ions, and improves the cycle performance of the lithium ion battery.
Disclosure of Invention
The invention provides an electrolyte, which at least aims to solve the problems of impedance increase, cycle performance reduction and the like of a lithium ion battery along with increase of hydrofluoric acid of the electrolyte in the conventional lithium ion battery.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
an electrolyte, which contains lithium salt and organic solvent;
the electrolyte also contains an additive shown as a formula (I):
wherein R is1、R2Independently selected from any one of hydrogen, alkyl with 1-20 carbon atoms, halogenated alkyl with 1-20 carbon atoms, phenyl, alkenyl with 1-20 carbon atoms and halogen.
Preferably, the additive shown in the formula (I) accounts for 0.1-2.0% of the electrolyte by mass.
Preferably, the additive shown in the formula (I) accounts for 0.3-1.0% of the electrolyte by mass.
Preferably, the additive represented by formula (I) is 1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-dimethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-diethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-dipropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-dibutyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-diisopropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-methyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-ethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-propyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-butyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-isopropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-methyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-ethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-propyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-butyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-isopropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-phenyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-vinyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-propenyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-trifluoromethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, methyl-4-trifluoromethyl-1, 3-methyl-2-thione, methyl-2-thione, methyl-thione, methyl-2-methyl-thione, and methyl-2-methyl-thione, 4-fluoro-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-chloro-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-bis (trifluoromethyl) -1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-bis (trichloromethyl) -1, 3-bis (trimethylsilyl) -imidazole-2-thione.
Preferably, the electrolyte also contains other additives.
Preferably, the other additive is at least one of ethylene sulfate, vinylene carbonate, 1, 3-propane sultone, 1-propylene-1, 3-sultone, methylene methanedisulfonate, vinyl ethylene carbonate, tris (trimethylsilane) phosphate, and tris (trimethylsilane) phosphite.
Preferably, the content of the other additives in the electrolyte is 0.01-5%.
Preferably, the lithium salt is LiPF6、LiBF4、LiBOB、LiDFOB、LiAsF6、LiPO2F2、LiN(CF3SO2)2、LiCF3SO3、LiClO4、LiN(CxF2x+1SO2)(CyF2y+1SO2) Wherein x and y are natural numbers;
and/or the organic solvent is a mixed organic solvent of a cyclic carbonate organic solvent and a chain carbonate organic solvent.
Preferably, in the electrolyte, the content of the cyclic carbonate organic solvent is 10-70% by mass; the mass percentage of the chain carbonate organic solvent is 15-80%.
Furthermore, the invention also provides a lithium ion battery using the electrolyte.
The lithium ion battery comprises the electrolyte, and the electrolyte is the electrolyte.
The beneficial technical effects of the invention are as follows:
compared with the prior art, the electrolyte provided by the invention is added with the additive shown in the formula (I), the additive shown in the formula (I) contains trimethylsilyl, and meanwhile, the five-membered heterocyclic ring contains carbon-carbon double bonds and the outside of the five-membered heterocyclic ring contains carbon-sulfur double bonds, wherein the trimethylsilyl can react with hydrofluoric acid generated in the electrolyte, so that the content of the hydrofluoric acid in the electrolyte is maintained at a lower level; the carbon-carbon double bond in the five-membered heterocycle and the carbon-sulfur double bond outside the five-membered heterocycle participate in the formation of an electrode-electrolyte interface film, the formed SEI film has good stability and is beneficial to the permeation of lithium ions, the SEI film with good stability inhibits the side reaction between an electrode and electrolyte and inhibits the gas generation of the lithium ion battery, and the SEI film with good lithium ion permeability effectively improves the conduction efficiency of the lithium ions between the anode and the cathode, so that the impedance of the lithium ion battery is reduced, and the cycle performance of the lithium ion battery is effectively improved.
According to the lithium ion battery provided by the invention, the electrolyte used by the lithium ion battery is the electrolyte containing the additive shown in the formula (I), so that the content of hydrofluoric acid in the lithium ion battery can be effectively inhibited, and the whole lithium ion battery has lower impedance and good cycle performance due to the fact that the surface of the negative electrode of the battery has the SEI film which is good in stability and beneficial to permeability of lithium ions.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following is a clear and complete description of the technical solutions of the disclosed embodiments of the present invention.
It is to be understood that the embodiments described are only a few of the presently disclosed embodiments, and not all embodiments. Based on the described embodiments, other embodiments obtained by persons of ordinary skill in the art without creative efforts belong to the protection scope of the invention.
Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. As used herein, the terms "first," "second," and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.
The invention provides an electrolyte which is suitable for a lithium ion battery.
The electrolyte contains lithium salt and organic solvent; the electrolyte also contains an additive shown as a formula (I):
wherein R is1、R2Independently selected from any one of hydrogen, alkyl with 1-20 carbon atoms, halogenated alkyl with 1-20 carbon atoms, phenyl, alkenyl with 1-20 carbon atoms and halogen.
When the electrolyte contains the additive shown in the formula (I), the trimethylsilyl group connected to the nitrogen atom of the additive shown in the formula (I) can react with hydrofluoric acid to consume hydrofluoric acid, so that the content of the hydrofluoric acid in the electrolyte can be effectively inhibited, and the influence of the hydrofluoric acid on the performances of the electrolyte and a lithium ion battery is reduced. Carbon-carbon double bonds and carbon-sulfur double bonds in the five-membered heterocycle participate in the formation of an electrode-electrolyte interface film (SEI film), and the formed SEI film has good stability and is beneficial to permeation of lithium ions. The stable SEI film can inhibit side reactions between the electrode and the electrolyte, so that the gas generation of the lithium ion battery is inhibited, and the good lithium ion permeability is favorable for improving the conduction efficiency of lithium ions between the anode and the cathode, so that the impedance of the lithium ion battery is reduced. Under the three effects of inhibiting hydrofluoric acid, stabilizing SEI film and improving lithium ion permeability, the cycle performance of the lithium ion battery can be effectively improved.
In some embodiments, the additive of formula (I) above may be 1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-dimethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-diethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-dipropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-dibutyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-diisopropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, or a combination thereof, 3-methyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-ethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-propyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-butyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-isopropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-methyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-ethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, methyl-2-thione, methyl-2-methyl-2-thione, methyl-2-methyl-thione, methyl-2-methyl-one, and methyl-ethyl-methyl-ethyl-2-one, 4-propyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-butyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-isopropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-phenyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-vinyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-propenyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-trifluoromethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, methyl-4-methyl-2-thione, methyl-2-thione, methyl-ethyl ketone, ethyl ketone, 4-fluoro-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-chloro-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-bis (trifluoromethyl) -1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-bis (trichloromethyl) -1, 3-bis (trimethylsilyl) -imidazole-2-thione.
In some preferred embodiments, the additive represented by formula (I) is present in the electrolyte in an amount of 0.1% to 2.0% by weight. If the content of the additive represented by formula (I) in the electrolyte is too small, for example, less than 0.1%, it cannot effectively inhibit hydrofluoric acid, and it is difficult to form a stable, dense and complete SEI film. If the addition amount is too large, because a stable, dense and complete SEI film is formed, the film continues to be formed even though the excessive addition amount is too large, and the permeability of lithium ions is reduced and the impedance of the lithium ion battery is increased.
In a more preferable embodiment, the additive represented by the formula (I) is contained in the electrolyte in an amount of 0.3 to 1.0% by mass. Considering the inconsistency of the surface roughness of the negative electrode due to the processing conditions, the amount of film formation is preferably 0.3% or more, and less than this value results in insufficient film forming ability and insignificant improvement of the lithium ion battery impedance, whereas if more than 1.0%, the lithium ion battery impedance tends to increase. Therefore, the additive represented by the formula (I) may be added in an amount of 0.3% to 1.0% such as 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.85%, 0.9%, 0.95% by mass in the electrolyte solution.
The lithium salt in the electrolyte is a solute of the electrolyte, which is a lithium salt of a conventional lithium ion battery electrolyte, such as LiPF6、LiBF4、LiBOB、LiDFOB、LiAsF6、LiPO2F2、LiN(CF3SO2)2、LiCF3SO3、LiClO4、LiN(CxF2x+1SO2)(CyF2y+1SO2) Wherein x and y are natural numbers;
since the conductivity of the electrolyte is reduced due to the low or high concentration of the lithium salt in the electrolyte, in some preferred embodiments, the molar concentration of the lithium salt in the electrolyte is (0.1-3) mol/L.
The lithium salt in the electrolyte is preferably LiPF from the viewpoint of energy density, power characteristics, and life of the lithium ion battery6、LiN(SO2F)2、LiBF4At least one of (1).
In some more preferred embodiments, the molar concentration of the lithium salt in the electrolyte is (0.3-2) mol/L.
The organic solvent is a mixed solvent of a cyclic carbonate organic solvent and a chain carbonate organic solvent.
For example, the cyclic carbonate organic solvent may be one or a combination of Ethylene Carbonate (EC), fluoroethylene carbonate (FEC), and Propylene Carbonate (PC).
The chain carbonate organic solvent can be one or a combination of dimethyl carbonate (DMC), Ethyl Methyl Carbonate (EMC) and diethyl carbonate (DEC).
In some embodiments, the content of the cyclic carbonate organic solvent in the electrolyte is 10 to 70 percent by mass; the mass percentage of the chain carbonate organic solvent in the electrolyte is 15-80%.
The electrolyte solution may further contain other additives, and for example, may contain one or a combination of several of common additives such as vinyl sulfate (DTD), Vinylene Carbonate (VC), 1, 3-Propane Sultone (PS), 1-propene-1, 3-sultone (PST), Methylene Methanedisulfonate (MMDS), Vinyl Ethylene Carbonate (VEC), tris (trimethylsilane) phosphate (TMSP), tris (trimethylsilane) phosphite (TMSPi).
In some embodiments, the other additive is 0.01 to 5% by mass of the electrolyte.
Correspondingly, the invention further provides a lithium ion battery taking the electrolyte as the electrolyte.
The lithium ion battery comprises an electrolyte, a positive electrode, a negative electrode, a diaphragm, a battery shell and the like. The positive electrode can be a conventional lithium ion battery positive electrode, for example, a positive active material in the positive electrode can be lithium iron phosphate, lithium cobaltate, a ternary material and the like, a current collector in the positive electrode is an aluminum foil, and a conductive agent in the positive electrode is acetylene black and the like; the binder in the positive electrode is polyvinylidene fluoride and the like; the negative active material in the negative electrode can be graphite, silicon and silicon alloy, tin-based alloy and the like; the current collector in the negative electrode is a copper foil; the conductive agent in the negative electrode is acetylene black and the like; the binder in the negative electrode is Styrene Butadiene Rubber (SBR), and the dispersant is sodium carboxymethylcellulose (CMC); the diaphragm is common polyolefin diaphragm, ceramic coating diaphragm and the like.
Because the electrolyte used by the lithium ion battery is the electrolyte containing the additive shown in the formula (I) and trimethylsilyl in the additive can react with hydrofluoric acid, the content of the hydrofluoric acid in the lithium ion battery can be effectively inhibited, and carbon-carbon double bonds and carbon-sulfur double bonds in the additive participate in the formation of an electrode-electrolyte interface film, so that the surface of the negative electrode of the battery has an SEI film which has good stability and is beneficial to permeation of lithium ions, and finally the whole lithium ion battery shows lower impedance and good cycle performance.
In order to more effectively explain the technical solution of the present invention and the effects thereof, the following is further explained by several examples.
Example 1
Embodiment 1 provides an electrolyte and a lithium ion battery including the same.
Wherein, the electrolyte contains lithium salt, organic solvent and 1, 3-bis (trimethylsilyl) -imidazole-2-thioketone; the lithium salt being LiPF6The molar concentration is 1.3M; the organic solvent is a mixture of ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, and the mass ratio of the organic solvent to the ethyl methyl carbonate is that the ethylene carbonate: diethyl carbonate: ethyl methyl carbonate 4:3: 3; the mass percentage of the 1, 3-bis (trimethylsilyl) -imidazole-2-thioketone in the electrolyte is 0.1%.
In the lithium ion battery, the positive electrode comprises a positive active material, a positive conductive agent, a positive binder and a positive current collector, wherein the positive active material is nickel cobalt lithium manganate (LiNi)0.8Co0.1Mn0.1O2) The positive electrode conductive agent is acetylene black (Super P), the positive electrode binder is polyvinylidene fluoride glue solution (PVDF), the positive electrode current collector is aluminum foil, and the positive electrode active material is prepared from the following components in percentage by mass: positive electrode conductive agent: the positive binder is 94:3: 3.
The negative electrode comprises a negative electrode active material, a negative electrode conductive agent, a negative electrode binder and a negative electrode current collector, wherein the negative electrode active material is graphite, the negative electrode conductive agent is acetylene black (Super P), the negative electrode binder is Styrene Butadiene Rubber (SBR), the dispersing agent is CMC, the negative electrode current collector is copper foil, and the negative electrode active material is prepared by the following steps in percentage by mass: negative electrode conductive agent: and (3) a negative electrode binder: dispersant 96:1:2: 1.
In order to save space, the compositions and the composition contents of the electrolytes of examples 2 to 14 and comparative examples 1 to 4 and the corresponding lithium ion batteries are shown in table 1.
TABLE 1 list of electrolyte parameters for examples 2-14 and comparative examples 1-4
In order to verify the effect of the additive shown in the formula (I) in the electrolyte, the electrolyte and the lithium ion battery corresponding to the examples 1 to 14 and the comparative examples 1 to 4 were respectively subjected to corresponding performance tests, including electrolyte performance test, cycle performance test, direct current impedance (DCR) test and high temperature gas production test.
Wherein,
firstly, electrolyte performance test
(1) Initial state: the newly prepared electrolytes of examples 1 to 14 and comparative examples 1 to 4 were each tested for hydrofluoric acid content in a glove box using a titration method, and the corresponding data are shown in column A of Table 2.
(2) Normal temperature storage: the newly prepared electrolytes of examples 1 to 14 and comparative examples 1 to 4 were sealed in an aluminum bottle in a glove box, and stored in an incubator at 25 ℃ for 30 days in the glove box, and the content of hydrofluoric acid in each electrolyte was measured by titration, and the corresponding data are shown in column B of table 2.
(3) High temperature storage: the newly prepared electrolytes of examples 1 to 14 and comparative examples 1 to 4 were sealed in an aluminum bottle in a glove box, and stored in an incubator at 60 ℃ for 10 days in the glove box, and the content of hydrofluoric acid in each electrolyte was measured by titration, and the corresponding data are shown in column C of table 2.
Second, testing the cycle performance
(1) Normal temperature cycle: the lithium ion batteries obtained in examples 1 to 14 and comparative examples 1 to 4 were subjected to a charge-discharge cycle test at 25 ℃ at a charge-discharge rate of 1C/1C in a range of (2.8 to 4.3) V, and the first discharge capacity and the discharge capacity after each cycle of the battery were recorded, and the capacity retention rate was calculated after 1000 cycles, and the obtained data was recorded in column D of table 2.
(2) High temperature cycle: the lithium ion batteries obtained in examples 1 to 14 and comparative examples 1 to 4 were subjected to charge-discharge cycle tests at 60 ℃ at a charge-discharge rate of 1C/1C in a range of (2.8 to 4.3) V, and the first discharge capacity of the battery and the discharge capacity after each cycle were recorded, and the capacity retention rate was recorded as discharge capacity per cycle/first discharge capacity × 100% after 500 cycles, and the obtained data was recorded in column E of table 2.
Three, DCR test
The lithium ion batteries obtained in examples 1 to 14 and comparative examples 1 to 4 were charged to 4.3V with a 1C constant current-constant voltage (CC-CV), the current was cut off at 0.05C, and then discharged at 1C capacity for 30min, adjusted to 50% SOC, and then left at 25 ℃ for 2h, and the pulse program was executed, 5C constant current discharged for 10s, and left at rest for 10min, thereby completing the test.
DCR (voltage before pulse discharge-voltage after pulse discharge)/discharge current × 100%, and the obtained data are recorded in column F of table 2.
Four, high temperature gassing test
The high temperature gassing test is demonstrated by testing the volume expansion rate at high temperatures. The specific testing steps are as follows:
the lithium ion batteries obtained in examples 1 to 14 and comparative examples 1 to 4 were charged to 4.3V at 1C, tested for volume by the drainage method, and the initial volume and the volume after storage at 80 ℃ for 7 days were recorded, and the volume expansion rate (volume after storage at 80 ℃ for 7 days-initial volume)/initial volume × 100% was recorded in column G of table 2.
TABLE 2 Performance test Table for electrolyte and lithium ion battery of examples 1 to 14 and comparative examples 1 to 4
| Example one another | A/(ppm) | B/(ppm) | C/(ppm) | D/(％) | E/(％) | F/(mΩ) | G/(％) |
| Example 1 | 33.89 | 65.2 | 91.28 | 72.4 | 63.4 | 19.6 | 49.1 |
| Example 2 | 32.75 | 52.24 | 73.28 | 85.1 | 78.2 | 16.7 | 37.2 |
| Example 3 | 36.81 | 44.37 | 48.38 | 88.9 | 82.4 | 15.2 | 30.5 |
| Example 4 | 35.91 | 42.84 | 44.22 | 86.5 | 80.2 | 16.3 | 28.3 |
| Example 5 | 34.62 | 41.08 | 42.2 | 79.6 | 72.8 | 19.2 | 25.1 |
| Example 6 | 33.46 | 39.08 | 38.2 | 65.2 | 59.9 | 23.4 | 23.2 |
| Example 7 | 37.29 | 45.87 | 49.23 | 87.2 | 81.4 | 15.5 | 32.4 |
| Example 8 | 35.35 | 45.29 | 47.07 | 86.9 | 80.8 | 15.7 | 29.9 |
| Example 9 | 36.32 | 43.13 | 46.89 | 88.1 | 80.9 | 15.8 | 33.5 |
| Example 10 | 31.76 | 46.8 | 50.92 | 87.9 | 82.3 | 15.2 | 35.1 |
| Example 11 | 35.84 | 44.27 | 46.51 | 87.1 | 81.4 | 15.3 | 33.7 |
| Examples12 | 37.27 | 45.91 | 50.12 | 87.6 | 82.1 | 15.7 | 32.2 |
| Example 13 | 34.51 | 44.31 | 49.15 | 87.1 | 84.1 | 17.2 | 25.3 |
| Example 14 | 33.87 | 43.15 | 44.23 | 91.4 | 82.5 | 14.7 | 31.2 |
| Comparative example 1 | 31.32 | 75.72 | 102.91 | 61.9 | 45.7 | 22.7 | 60.8 |
| Comparative example 2 | 32.33 | 43.44 | 47.76 | 83.4 | 79.6 | 17.1 | 33.2 |
| Comparative example 3 | 31.98 | 45.1 | 46.59 | 84.1 | 80.4 | 15.0 | 39.2 |
| Comparative example 4 | 32.22 | 73.67 | 105.12 | 88.1 | 82.5 | 16.1 | 33.1 |
The following analyses were performed based on the data shown in tables 1 and 2:
(1) it can be seen from the results of the electrolyte performance tests of examples 1 to 6 and comparative example 1 that:
the chemical structures of the additives in the electrolytes of examples 1 to 6 can be summarized in the chemical structure shown in formula (I), that is, the additives have the chemical structure shown in formula (I). Whether the additive shown in the formula (I) is added into the newly prepared electrolyte or not is judged, the concentration difference of hydrofluoric acid in the electrolyte is not large, but after the electrolyte with the additive shown in the formula (I) is added, the content of hydrofluoric acid is obviously lower than that in the electrolyte without the additive shown in the formula (I), and the inhibition effect on the content of hydrofluoric acid is better as the content of the additive shown in the formula (I) in the electrolyte is increased.
The main reasons are: the trimethylsilyl functional group in the additive shown in the formula (I) can react with HF, so that the content of HF in the electrolyte is inhibited, and the higher the concentration of the additive shown in the formula (I) in the electrolyte is, the better the inhibition effect is.
As can be seen from the DCR test results of examples 1-6 and comparative example 1, the additive shown in formula (I) can improve the DCR of the lithium ion battery and improve the cycle performance of the lithium ion battery.
The main reasons are: the additive having the formula (I) can form a stable SEI film at an electrode-electrolyte interface, which is advantageous for lithium ion permeation.
It can be seen from examples 1 to 6 that, when the concentration of the additive is low, the improvement effect is enhanced as the concentration of the additive represented by formula (I) is increased, but when the concentration of the additive represented by formula (I) is increased to 0.5%, the DCR and the cycle performance of the lithium ion battery are deteriorated by continuously adding the additive represented by formula (I), because when the concentration is low, the SEI film formed is more stable as the concentration is increased, the effect of suppressing the side reaction of the electrode-electrolyte is enhanced, and the cycle performance is improved. When the concentration is increased to 0.5%, the mass concentration is increased continuously, so that the formed SEI is too thick, the permeability of lithium ions is poor, and the polarization is increased, thereby causing the DCR and the cycle performance of the lithium ion battery to be deteriorated.
As can be seen from the high-temperature gas production test results of examples 1-6 and comparative example 1, the additive shown in formula (I) can improve the gas production performance of the lithium ion battery, and the improvement effect is enhanced with the increase of the concentration. The additive shown in the formula (I) can form a stable SEI film at an electrode-electrolyte interface to inhibit side reactions between an electrode and an electrolyte, and the formed interface film is thicker and more stable along with the increase of the concentration of the additive, so that the effect of inhibiting the side reactions is stronger, and the effect of improving the gas generation is also obvious.
(2) As can be seen from the electrolyte performance test results of example 3 and comparative example 2:
the carbon-oxygen double bond and the carbon-sulfur double bond have no influence on the HF content in the electrolyte. The reason is that the additives play a role in inhibiting hydrofluoric acid is trimethylsilyl on nitrogen atoms, and the trimethylsilyl plays a role in inhibiting hydrofluoric acid, and is not related to carbon-oxygen double bonds or carbon-sulfur double bonds.
From the cycle performance and DCR test results of example 3 and comparative example 2, it can be seen that: compared with carbon-oxygen double bonds, the carbon-sulfur double bonds improve the cycle performance of the lithium ion battery, and the impedance reduction effect is more obvious. The carbon-sulfur double bonds can form an interface film rich in sulfur elements on an electrode-electrolyte interface, so that the permeability of lithium ions is increased, the impedance is improved, the polarization is reduced, and the cycle performance of the lithium ion battery is improved.
(3) As can be seen from the electrolyte performance test results of example 3 and comparative example 3:
whether the five-membered heterocycle contains the carbon-carbon double bond or not has no influence on the content of HF, because the reason for inhibiting HF is caused by the trimethylsilyl group of the side chain and is irrelevant to the carbon-carbon double bond.
From the cycle performance and DCR test results of example 3 and comparative example 3, it can be seen that: the existence of the carbon-carbon double bond can improve the cycle performance of the lithium ion battery and inhibit high-temperature gas generation. The reason is that the existence of carbon-carbon double bonds can enable the formed SEI film to be more compact and stable, and the inhibition effect on the side reaction of the electrode-electrolyte is better, so that the cycle performance of the lithium ion battery is improved. The DCR performance of the lithium ion battery may be slightly deteriorated by the presence of the carbon-carbon double bond, which may be caused by further improvement of the interface film compactness due to the carbon-carbon double bond, thereby reducing the lithium ion permeability.
(4) As can be seen from the electrolyte performance results of example 3 and comparative example 4: trimethylsilyl is the root cause for the inhibition of the HF content with the additive of formula (I).
As can be seen from the DCR test results of example 3 and comparative example 3: the trimethylsilyl can improve the DCR performance of the lithium ion battery, and has little influence on other performances of the lithium ion battery. This is probably because the reaction product of trimethylsilyl in the electrolyte in the additive has the effect of improving the DCR of the lithium ion battery.
(5) From the results of the electrolyte performance test and the cycle performance test of examples 3 and 7 to 12, it can be seen that: r1、R2The substitution of the medium methyl, ethyl, phenyl, fluorine and trifluoromethyl has little influence on the performance of the additive shown in the formula (I), and the trimethyl silicon base, carbon-sulfur double bond and carbon-carbon double bond in the structure of the additive shown in the formula (I) are reasons for improving the performance of the lithium ion battery.
(6) From the results of the electrolyte performance test and the cell performance test of example 3 and example 13, it can be seen that the additive 1, 3-Propane Sultone (PS) has little influence on the HF content because the PS molecule does not contain a structure capable of reacting with HF.
The additive shown in the formula (I) is used in combination with PS, so that the gas production and high-temperature cycle performance of the battery cell can be further improved, the reason is that the combination of the two additives improves the compactness of the SEI film, the electrode-electrolyte side reaction is further inhibited, the gas production and high-temperature cycle are improved, but the compact SEI film can cause the reduction of the permeability of lithium ions, the deterioration of the normal-temperature cycle performance behavior and the increase of impedance.
(7) From the results of the electrolyte performance tests and the cell performance tests of examples 3 and 14, it can be seen that the use of the additive of formula (I) in combination with tris (trimethylsilane) phosphite (TMSPi) improves the electrolyte storage HF performance, since trimethylsilane in TMSPi can also react with HF, synergistically inhibiting the HF content in the electrolyte.
The additive shown in the formula (I) and TMSPi are used together, so that the normal-temperature cycle performance and the battery resistance of the battery can be improved, the high-temperature cycle performance is not greatly influenced, and the probable reason is guessed that the combined use of the additive shown in the formula (I) and the TMSPi enables an SEI film to be richer in phosphorus and sulfur components, improves the conduction of lithium ions in an interface film, reduces the resistance and improves the normal-temperature cycle performance. However, the combination of the two does not further improve the interface film densification degree, and the gas generating performance is not improved.
In summary, the analysis of the examples and the comparative examples fully shows that the additive shown in formula (I) has three functional groups, namely, trimethylsilyl group, carbon-sulfur double bond, and carbon-carbon double bond, so that the hydrofluoric acid content of the electrolyte is effectively inhibited, and the additive is beneficial to forming a compact SEI film with good stability and good lithium ion permeability, reducing the impedance of the lithium ion battery, and improving the cycle performance.
It should be noted that, since the present invention mainly discusses the effect of the additive shown in formula (I) on the performance of the lithium ion battery, in order to control a single variable, the positive electrode and the negative electrode of other examples and comparative examples are the same as those of example 1, but it is not suggested that the additive shown in formula (I) exhibits good performance only if the positive electrode active material, the negative electrode active material and other electrolyte components of example 1 are all present. The performance of the additive shown in formula (I) is described as an example of the positive electrode active material, the negative electrode active material, and other electrolyte components in example 1, but the invention is not limited to the types of the positive electrode active material, the negative electrode active material, and other electrolyte components of the lithium ion battery, and the additive shown in formula (I) of the invention also exhibits similar characteristics in the lithium ion battery formed of other positive electrode active materials, negative electrode active materials, and other electrolyte components, and the like, which are characteristics of the additive shown in formula (I) itself and are not affected by the positive electrode active material, the negative electrode active material, other electrolyte components, and the like.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the present specification, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. The electrolyte is characterized by comprising a lithium salt and an organic solvent;
the electrolyte also contains an additive shown as a formula (I):
wherein R is1、R2Independently selected from any one of hydrogen, alkyl with 1-20 carbon atoms, halogenated alkyl with 1-20 carbon atoms, phenyl, alkenyl with 1-20 carbon atoms and halogen.
2. The electrolyte of claim 1, wherein the additive represented by the formula (I) is contained in the electrolyte in an amount of 0.1-2.0% by mass.
3. The electrolyte of claim 1, wherein the additive represented by the formula (I) is contained in the electrolyte in an amount of 0.3 to 1.0% by mass.
4. The electrolyte according to claim 1 or 2 or 3, wherein the additive represented by formula (I) is 1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-dimethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-diethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-dipropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-dibutyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-diisopropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, or, 3-methyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-ethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-propyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-butyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 3-isopropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-methyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-ethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, methyl-2-thione, methyl-2-methyl-2-thione, methyl-2-methyl-thione, methyl-2-methyl-one, and methyl-ethyl-methyl-ethyl-2-one, 4-propyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-butyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-isopropyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-phenyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-vinyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-propenyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-trifluoromethyl-1, 3-bis (trimethylsilyl) -imidazole-2-thione, methyl-4-methyl-2-thione, methyl-2-thione, methyl-ethyl ketone, ethyl ketone, 4-fluoro-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4-chloro-1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-bis (trifluoromethyl) -1, 3-bis (trimethylsilyl) -imidazole-2-thione, 4, 5-bis (trichloromethyl) -1, 3-bis (trimethylsilyl) -imidazole-2-thione.
5. The electrolyte of claim 1, 2 or 3, wherein the electrolyte further comprises other additives.
6. The electrolyte of claim 5, wherein the other additive is at least one of vinyl sulfate, vinylene carbonate, 1, 3-propane sultone, 1-propene-1, 3-sultone, methylene methanedisulfonate, vinyl ethylene carbonate, tris (trimethylsilane) phosphate, and tris (trimethylsilane) phosphite.
7. The electrolyte of claim 5, wherein the other additive is present in the electrolyte in an amount of 0.01 to 5% by weight.
8. The electrolyte of claim 1, wherein the lithium salt is LiPF6、LiBF4、LiBOB、LiDFOB、LiAsF6、LiPO2F2、LiN(CF3SO2)2、LiCF3SO3、LiClO4、LiN(CxF2x+1SO2)(CyF2y+1SO2) Wherein x and y are natural numbers;
and/or the organic solvent is a mixed organic solvent of a cyclic carbonate organic solvent and a chain carbonate organic solvent.
9. The electrolyte according to claim 8, wherein the cyclic carbonate organic solvent is present in the electrolyte in an amount of 10 to 70% by weight; the mass percentage of the chain carbonate organic solvent is 15-80%.
10. A lithium ion battery comprising an electrolyte, wherein the electrolyte is the electrolyte according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010542103.6A CN111668544B (en) | 2020-06-15 | 2020-06-15 | Electrolyte and lithium ion battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010542103.6A CN111668544B (en) | 2020-06-15 | 2020-06-15 | Electrolyte and lithium ion battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111668544A CN111668544A (en) | 2020-09-15 |
| CN111668544B true CN111668544B (en) | 2022-04-05 |
Family
ID=72388104
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010542103.6A Active CN111668544B (en) | 2020-06-15 | 2020-06-15 | Electrolyte and lithium ion battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111668544B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113328142A (en) * | 2021-05-26 | 2021-08-31 | 恒大新能源技术(深圳)有限公司 | Electrolyte additive, electrolyte and lithium ion battery |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20080110404A (en) * | 2007-06-15 | 2008-12-18 | 주식회사 엘지화학 | Additive for non-aqueous electrolyte and secondary battery using the same |
| CN109535292A (en) * | 2017-09-22 | 2019-03-29 | 中国石油天然气股份有限公司 | Polypropylene catalyst containing thiourea-containing compound, and preparation method and application thereof |
| CN109659619A (en) * | 2019-01-04 | 2019-04-19 | 蜂巢能源科技有限公司 | Electrolyte and its preparation method and application |
| CN110707360A (en) * | 2019-10-21 | 2020-01-17 | 广州天赐高新材料股份有限公司 | Lithium ion battery electrolyte, lithium ion battery and application |
-
2020
- 2020-06-15 CN CN202010542103.6A patent/CN111668544B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20080110404A (en) * | 2007-06-15 | 2008-12-18 | 주식회사 엘지화학 | Additive for non-aqueous electrolyte and secondary battery using the same |
| CN109535292A (en) * | 2017-09-22 | 2019-03-29 | 中国石油天然气股份有限公司 | Polypropylene catalyst containing thiourea-containing compound, and preparation method and application thereof |
| CN109659619A (en) * | 2019-01-04 | 2019-04-19 | 蜂巢能源科技有限公司 | Electrolyte and its preparation method and application |
| CN110707360A (en) * | 2019-10-21 | 2020-01-17 | 广州天赐高新材料股份有限公司 | Lithium ion battery electrolyte, lithium ion battery and application |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111668544A (en) | 2020-09-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109687025B (en) | Electrolyte, electrochemical device and electronic device comprising same | |
| CN109873205B (en) | Electrolyte suitable for silicon-carbon cathode and lithium ion battery containing electrolyte | |
| JP2023043812A (en) | Non-aqueous electrolyte for lithium ion battery and use thereof | |
| CN111048830B (en) | Nonaqueous electrolyte solution and lithium ion secondary battery | |
| CN108258297B (en) | Electrolyte and lithium ion battery | |
| CN110931865A (en) | Novel additive-containing electrolyte for lithium ion battery and lithium ion battery | |
| CN109687026B (en) | High-voltage ternary lithium ion battery electrolyte and lithium ion battery containing same | |
| CN115588779A (en) | High-temperature nonaqueous electrolyte solution and secondary battery | |
| CN114512721A (en) | Lithium ion battery non-aqueous electrolyte and lithium ion battery | |
| CN110690501A (en) | Electrolyte solution and electrochemical device | |
| CN110416611B (en) | Non-aqueous electrolyte of lithium ion battery and lithium ion battery using same | |
| 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 | |
| CN112928328A (en) | Lithium ion battery electrolyte containing silane sulfonamide compound and lithium ion secondary battery | |
| CN111883834B (en) | Non-aqueous lithium ion battery electrolyte additive, electrolyte containing non-aqueous lithium ion battery electrolyte additive and lithium ion battery | |
| CN111668544B (en) | Electrolyte and lithium ion battery | |
| CN112531213A (en) | Non-aqueous electrolyte with high-temperature characteristics and normal-temperature cycle, application thereof and lithium ion battery | |
| CN112072179A (en) | Electrolyte, lithium ion battery and vehicle | |
| CN113429433B (en) | Lithium ion battery electrolyte and lithium ion battery | |
| CN115642256A (en) | Organic positive electrode additive and lithium ion battery | |
| CN110247116B (en) | Non-aqueous electrolyte of lithium ion battery and lithium ion battery using same | |
| CN110416609B (en) | Non-aqueous electrolyte of lithium ion battery and lithium ion battery comprising same | |
| CN114464886A (en) | Lithium ion battery non-aqueous electrolyte and lithium ion battery | |
| CN114039093A (en) | Electrolyte additive, electrolyte, lithium ion battery and application of electrolyte additive and electrolyte | |
| CN115224361A (en) | Non-aqueous electrolyte and secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address |
Address after: 518000 1-2 Floor, Building A, Xinwangda Industrial Park, No. 18 Tangjianan Road, Gongming Street, Guangming New District, Shenzhen City, Guangdong Province Patentee after: Xinwangda Power Technology Co.,Ltd. Address before: 518107 Xinwangda Industrial Park, No.18, Tangjia south, Gongming street, Guangming New District, Shenzhen City, Guangdong Province Patentee before: SUNWODA ELECTRIC VEHICLE BATTERY Co.,Ltd. |
|
| CP03 | Change of name, title or address |