JP5235437B2 - Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery - Google Patents
Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery Download PDFInfo
- Publication number
- JP5235437B2 JP5235437B2 JP2008024651A JP2008024651A JP5235437B2 JP 5235437 B2 JP5235437 B2 JP 5235437B2 JP 2008024651 A JP2008024651 A JP 2008024651A JP 2008024651 A JP2008024651 A JP 2008024651A JP 5235437 B2 JP5235437 B2 JP 5235437B2
- Authority
- JP
- Japan
- Prior art keywords
- secondary battery
- aqueous electrolyte
- cooch
- aqueous
- carboxylic acid
- 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
- 239000011255 nonaqueous electrolyte Substances 0.000 title claims abstract description 125
- 150000001733 carboxylic acid esters Chemical class 0.000 claims abstract description 55
- 150000001875 compounds Chemical class 0.000 claims abstract description 38
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 29
- 239000001257 hydrogen Substances 0.000 claims abstract description 26
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 26
- 239000011737 fluorine Substances 0.000 claims abstract description 24
- 229910052731 fluorine Inorganic materials 0.000 claims abstract description 24
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 23
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 19
- 125000001153 fluoro group Chemical group F* 0.000 claims abstract description 19
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 19
- 125000000217 alkyl group Chemical group 0.000 claims abstract description 13
- 239000002904 solvent Substances 0.000 claims abstract description 13
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims abstract description 7
- 239000003125 aqueous solvent Substances 0.000 claims description 44
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 claims description 42
- 229910052799 carbon Inorganic materials 0.000 claims description 19
- 239000003792 electrolyte Substances 0.000 claims description 17
- 239000008151 electrolyte solution Substances 0.000 claims description 17
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 16
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 15
- -1 carboxylate ester Chemical class 0.000 claims description 11
- 229910003002 lithium salt Inorganic materials 0.000 claims description 11
- 159000000002 lithium salts Chemical class 0.000 claims description 11
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 10
- WDXYVJKNSMILOQ-UHFFFAOYSA-N 1,3,2-dioxathiolane 2-oxide Chemical compound O=S1OCCO1 WDXYVJKNSMILOQ-UHFFFAOYSA-N 0.000 claims description 7
- 229910013075 LiBF Inorganic materials 0.000 claims description 7
- PMGBATZKLCISOD-UHFFFAOYSA-N methyl 3,3,3-trifluoropropanoate Chemical group COC(=O)CC(F)(F)F PMGBATZKLCISOD-UHFFFAOYSA-N 0.000 claims description 7
- BJWMSGRKJIOCNR-UHFFFAOYSA-N 4-ethenyl-1,3-dioxolan-2-one Chemical compound C=CC1COC(=O)O1 BJWMSGRKJIOCNR-UHFFFAOYSA-N 0.000 claims description 6
- 150000002431 hydrogen Chemical group 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 abstract description 9
- 125000004432 carbon atom Chemical group C* 0.000 abstract 1
- 230000015556 catabolic process Effects 0.000 abstract 1
- 238000006731 degradation reaction Methods 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 33
- 238000003860 storage Methods 0.000 description 26
- 239000012046 mixed solvent Substances 0.000 description 22
- 238000002360 preparation method Methods 0.000 description 15
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 11
- 229910013870 LiPF 6 Inorganic materials 0.000 description 11
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 11
- VLKZOEOYAKHREP-UHFFFAOYSA-N methyl pentane Natural products CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 7
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 7
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 6
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 6
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 6
- 239000010439 graphite Substances 0.000 description 6
- 229910002804 graphite Inorganic materials 0.000 description 6
- 238000002156 mixing Methods 0.000 description 6
- 238000011084 recovery Methods 0.000 description 6
- 238000003756 stirring Methods 0.000 description 6
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 description 5
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 5
- 238000013461 design Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 239000007774 positive electrode material Substances 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 4
- ZCSHNCUQKCANBX-UHFFFAOYSA-N lithium diisopropylamide Chemical compound [Li+].CC(C)[N-]C(C)C ZCSHNCUQKCANBX-UHFFFAOYSA-N 0.000 description 4
- YIXJRHPUWRPCBB-UHFFFAOYSA-N magnesium nitrate Chemical compound [Mg+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O YIXJRHPUWRPCBB-UHFFFAOYSA-N 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000007773 negative electrode material Substances 0.000 description 4
- 230000009257 reactivity Effects 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 229910013063 LiBF 4 Inorganic materials 0.000 description 3
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 3
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 3
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 description 3
- 239000002131 composite material Substances 0.000 description 3
- UAOMVDZJSHZZME-UHFFFAOYSA-N diisopropylamine Chemical compound CC(C)NC(C)C UAOMVDZJSHZZME-UHFFFAOYSA-N 0.000 description 3
- 239000002905 metal composite material Substances 0.000 description 3
- 229910052723 transition metal Inorganic materials 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 2
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- IJOOHPMOJXWVHK-UHFFFAOYSA-N chlorotrimethylsilane Chemical compound C[Si](C)(C)Cl IJOOHPMOJXWVHK-UHFFFAOYSA-N 0.000 description 2
- CKFRRHLHAJZIIN-UHFFFAOYSA-N cobalt lithium Chemical compound [Li].[Co] CKFRRHLHAJZIIN-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- XBDQKXXYIPTUBI-UHFFFAOYSA-N dimethylselenoniopropionate Natural products CCC(O)=O XBDQKXXYIPTUBI-UHFFFAOYSA-N 0.000 description 2
- 238000004821 distillation Methods 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- 238000003682 fluorination reaction Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 description 2
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229940017219 methyl propionate Drugs 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 239000012044 organic layer Substances 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- ZOWSJJBOQDKOHI-UHFFFAOYSA-N 2,2,2-trifluoroethyl acetate Chemical compound CC(=O)OCC(F)(F)F ZOWSJJBOQDKOHI-UHFFFAOYSA-N 0.000 description 1
- 229910000838 Al alloy Inorganic materials 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
- 229910013684 LiClO 4 Inorganic materials 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- 229910013131 LiN Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- RJUFJBKOKNCXHH-UHFFFAOYSA-N Methyl propionate Chemical compound CCC(=O)OC RJUFJBKOKNCXHH-UHFFFAOYSA-N 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 229910000978 Pb alloy Inorganic materials 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 229910000676 Si alloy Inorganic materials 0.000 description 1
- 229910001128 Sn alloy Inorganic materials 0.000 description 1
- 229910006404 SnO 2 Inorganic materials 0.000 description 1
- 235000002597 Solanum melongena Nutrition 0.000 description 1
- 244000061458 Solanum melongena Species 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- RHQDFWAXVIIEBN-UHFFFAOYSA-N Trifluoroethanol Chemical compound OCC(F)(F)F RHQDFWAXVIIEBN-UHFFFAOYSA-N 0.000 description 1
- JFBZPFYRPYOZCQ-UHFFFAOYSA-N [Li].[Al] Chemical compound [Li].[Al] JFBZPFYRPYOZCQ-UHFFFAOYSA-N 0.000 description 1
- ZVLDJSZFKQJMKD-UHFFFAOYSA-N [Li].[Si] Chemical compound [Li].[Si] ZVLDJSZFKQJMKD-UHFFFAOYSA-N 0.000 description 1
- WETWJCDKMRHUPV-UHFFFAOYSA-N acetyl chloride Chemical compound CC(Cl)=O WETWJCDKMRHUPV-UHFFFAOYSA-N 0.000 description 1
- 239000012346 acetyl chloride Substances 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- CJBYUPBUSUVUFH-UHFFFAOYSA-N buta-1,3-diene;carbonic acid Chemical class C=CC=C.OC(O)=O CJBYUPBUSUVUFH-UHFFFAOYSA-N 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 150000005678 chain carbonates Chemical class 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 150000005676 cyclic carbonates Chemical class 0.000 description 1
- 238000002484 cyclic voltammetry Methods 0.000 description 1
- VILAVOFMIJHSJA-UHFFFAOYSA-N dicarbon monoxide Chemical group [C]=C=O VILAVOFMIJHSJA-UHFFFAOYSA-N 0.000 description 1
- 229940043279 diisopropylamine Drugs 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- GZKHDVAKKLTJPO-UHFFFAOYSA-N ethyl 2,2-difluoroacetate Chemical compound CCOC(=O)C(F)F GZKHDVAKKLTJPO-UHFFFAOYSA-N 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- JWZCKIBZGMIRSW-UHFFFAOYSA-N lead lithium Chemical compound [Li].[Pb] JWZCKIBZGMIRSW-UHFFFAOYSA-N 0.000 description 1
- DLEDOFVPSDKWEF-UHFFFAOYSA-N lithium butane Chemical compound [Li+].CCC[CH2-] DLEDOFVPSDKWEF-UHFFFAOYSA-N 0.000 description 1
- UIDWHMKSOZZDAV-UHFFFAOYSA-N lithium tin Chemical compound [Li].[Sn] UIDWHMKSOZZDAV-UHFFFAOYSA-N 0.000 description 1
- ACFSQHQYDZIPRL-UHFFFAOYSA-N lithium;bis(1,1,2,2,2-pentafluoroethylsulfonyl)azanide Chemical compound [Li+].FC(F)(F)C(F)(F)S(=O)(=O)[N-]S(=O)(=O)C(F)(F)C(F)(F)F ACFSQHQYDZIPRL-UHFFFAOYSA-N 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 235000019260 propionic acid Nutrition 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- IUVKMZGDUIUOCP-BTNSXGMBSA-N quinbolone Chemical compound O([C@H]1CC[C@H]2[C@H]3[C@@H]([C@]4(C=CC(=O)C=C4CC3)C)CC[C@@]21C)C1=CCCC1 IUVKMZGDUIUOCP-BTNSXGMBSA-N 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- PNGLEYLFMHGIQO-UHFFFAOYSA-M sodium;3-(n-ethyl-3-methoxyanilino)-2-hydroxypropane-1-sulfonate;dihydrate Chemical compound O.O.[Na+].[O-]S(=O)(=O)CC(O)CN(CC)C1=CC=CC(OC)=C1 PNGLEYLFMHGIQO-UHFFFAOYSA-M 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- LALRXNPLTWZJIJ-UHFFFAOYSA-N triethylborane Chemical compound CCB(CC)CC LALRXNPLTWZJIJ-UHFFFAOYSA-N 0.000 description 1
- DTQVDTLACAAQTR-UHFFFAOYSA-N trifluoroacetic acid Substances OC(=O)C(F)(F)F DTQVDTLACAAQTR-UHFFFAOYSA-N 0.000 description 1
- VPAYJEUHKVESSD-UHFFFAOYSA-N trifluoroiodomethane Chemical compound FC(F)(F)I VPAYJEUHKVESSD-UHFFFAOYSA-N 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Images
Classifications
-
- 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
- Secondary Cells (AREA)
Abstract
Description
本発明は、二次電池用非水電解液及びこのような非水電解液を用いた非水電解液二次電池に係り、特に、非水電解液が電極と反応するのを抑制し、高温条件下においても電池容量が低下するのを抑制して、長期にわたって良好な電池特性が得られるようにした点に特徴を有するものである。 The present invention relates to a non-aqueous electrolyte for a secondary battery and a non-aqueous electrolyte secondary battery using such a non-aqueous electrolyte, and in particular, suppresses the non-aqueous electrolyte from reacting with an electrode, It is characterized in that the battery capacity is prevented from decreasing even under conditions, and good battery characteristics can be obtained over a long period of time.
近年、高出力，高エネルギー密度の新型二次電池として、非水電解液を用い、リチウムイオンを正極と負極との間で移動させて充放電を行うようにした非水電解液二次電池が広く利用されている。 In recent years, as a new secondary battery with high output and high energy density, there has been a non-aqueous electrolyte secondary battery that uses a non-aqueous electrolyte and charges and discharges by moving lithium ions between the positive and negative electrodes. Widely used.
そして、このような非水電解液二次電池において、良好な充放電特性が得られるようにするため、従来においては、上記の非水電解液として、非水系溶媒に、エチレンカーボネート等の環状炭酸エステルと、ジエチルカーボネート，エチルメチルカーボネート，ジメチルカーボネート等の鎖状炭酸エステルとを混合させた混合溶媒を用い、この混合溶媒にＬｉＰＦ6やＬｉＢＦ4等のリチウム塩からなる電解質を溶解したものが使用されている。 In order to obtain good charge / discharge characteristics in such a non-aqueous electrolyte secondary battery, conventionally, as the non-aqueous electrolyte, a cyclic carbonate such as ethylene carbonate is used as a non-aqueous solvent. Uses a mixed solvent in which an ester and a chain carbonate such as diethyl carbonate, ethyl methyl carbonate, dimethyl carbonate, etc. are mixed, and an electrolyte composed of a lithium salt such as LiPF 6 or LiBF 4 is used in this mixed solvent Has been.
しかし、上記のような非水電解液を用いた非水電解液二次電池の耐久性等を評価するために、このような非水電解液二次電池を充電状態で高温条件下に放置させる充電保存試験を行った場合、上記の非水電解液が正極や負極と副反応を起こし、電池容量が低下するという問題があった。 However, in order to evaluate the durability of the non-aqueous electrolyte secondary battery using the non-aqueous electrolyte as described above, such a non-aqueous electrolyte secondary battery is left in a charged state under a high temperature condition. When a charge storage test was performed, there was a problem that the non-aqueous electrolyte had a side reaction with the positive electrode and the negative electrode, resulting in a decrease in battery capacity.
そこで、近年においては、各種のフッ素化鎖状カルボン酸エステルを、非水電解液の非水系溶媒として用いたり、非水電解液に添加させたりすることが提案されている。（例えば、特許文献１〜５参照。）
Therefore, in recent years, it has been proposed to use various fluorinated chain carboxylic acid esters as a non-aqueous solvent for a non-aqueous electrolyte or to add to the non-aqueous electrolyte. (For example, see
ここで、一般的に溶媒分子構造中にフッ素を導入すると、耐酸化性が向上することから、正極と非水電解液との反応を抑制することができる。しかし、フッ素を導入すると非水電解液の粘度の増加が起こり、また、耐還元性が低下することから負極との反応性が増大してしまう。特に、フッ素を導入する位置は、負極との反応性を大きく左右する。 Here, generally, when fluorine is introduced into the solvent molecular structure, the oxidation resistance is improved, so that the reaction between the positive electrode and the nonaqueous electrolytic solution can be suppressed. However, when fluorine is introduced, the viscosity of the non-aqueous electrolyte increases, and the resistance to reduction increases because the resistance to reduction decreases. In particular, the position where fluorine is introduced greatly affects the reactivity with the negative electrode.
しかし、これらの特許文献においては、どのような種類のフッ素化鎖状カルボン酸エステルを用いるかは様々であり、フッ素が置換される炭素の位置について、特許文献１，２においては、α炭素における水素がフッ素で置換されたものが示されているだけであり、また特許文献３，４においては、α炭素とそれ以外の炭素の何れであってもよいとされており、また特許文献５においては、α炭素における水素がフッ素で置換されたものが好ましいと記載されている。
However, in these patent documents, what kind of fluorinated chain carboxylic acid ester is used varies. Regarding the position of carbon where fluorine is substituted, in
そして、非水電解液の非水系溶媒として、α炭素における水素がフッ素で置換されたフッ素化鎖状カルボン酸エステルを用いた場合、例えば、トリフルオロ酢酸エチルＣＦ3ＣＯＯＣＨ2ＣＨ3を用いた場合には、電解質として用いるＬｉＰＦ6等のリチウム塩が適切に溶解されなくなるという問題があった。また、ジフルオロ酢酸エチルＣＨＦ2ＣＯＯＣＨ2ＣＨ3を用いた場合には、電解質として用いるＬｉＰＦ6等のリチウム塩が溶解されるが、負極との反応性が高くなり、この非水電解液二次電池を充電状態で高温条件下に放置させると、電池容量や電池特性が大きく低下するという問題があった。このように、α炭素における水素がフッ素で置換されたフッ素化鎖状カルボン酸エステルでは、十分な電池特性が得られなかった。 When a fluorinated chain carboxylic acid ester in which hydrogen at α-carbon is substituted with fluorine is used as the non-aqueous solvent of the non-aqueous electrolyte, for example, when trifluoroacetic acid ethyl CF 3 COOCH 2 CH 3 is used Has a problem that lithium salts such as LiPF 6 used as an electrolyte are not properly dissolved. Further, when ethyl difluoroacetate CHF 2 COOCH 2 CH 3 is used, a lithium salt such as LiPF 6 used as an electrolyte is dissolved, but the reactivity with the negative electrode is increased, and this non-aqueous electrolyte secondary battery When the battery is left in a charged state under a high temperature condition, there is a problem that the battery capacity and battery characteristics are greatly reduced. Thus, with the fluorinated chain carboxylic acid ester in which the hydrogen at the α-carbon is substituted with fluorine, sufficient battery characteristics cannot be obtained.
さらに、非水系溶媒として、α炭素以外の炭素における水素がフッ素で置換されたフッ素化鎖状カルボン酸エステルを用いた場合においては、負極との反応性を低減させることができるが、依然として、この非水電解液二次電池を充電状態で高温条件下において放置させた場合に、電池容量や電池特性が低下するという問題があり、またこのようなフッ素化鎖状カルボン酸エステルを他の非水系溶媒と組み合わせて使用する場合においても、組み合わせる他の溶媒が適切でないと、この非水電解液二次電池における初期容量が低下し、また高温条件下に放置させた場合に、電池容量や電池特性が低下するという問題があった。 Furthermore, when a fluorinated chain carboxylic acid ester in which hydrogen in carbon other than α-carbon is substituted with fluorine as a non-aqueous solvent, the reactivity with the negative electrode can be reduced, but this still When a non-aqueous electrolyte secondary battery is left in a charged state under high temperature conditions, there is a problem that the battery capacity and battery characteristics deteriorate, and such fluorinated chain carboxylic acid esters are not suitable for other non-aqueous systems. Even when used in combination with a solvent, if the other solvent to be combined is not appropriate, the initial capacity of this non-aqueous electrolyte secondary battery is reduced, and when left in high temperature conditions, the battery capacity and battery characteristics are reduced. There was a problem that decreased.
このように、非水系溶媒のフッ素化により、正極との反応を抑制することができても、負極との反応性が増大することから、良好な電池特性を得ることはできなかった。
本発明は、非水電解液を用いた非水電解液二次電池における上記のような問題を解決することを課題とするものであり、非水電解液が電極と反応するのが抑制されて、高温条件下においても電池容量が低下するのが抑制され、長期にわたって良好な電池特性が得られるようにすることを課題とするものである。 This invention makes it a subject to solve the above problems in the nonaqueous electrolyte secondary battery using a nonaqueous electrolyte, and it is suppressed that a nonaqueous electrolyte reacts with an electrode. An object of the present invention is to prevent the battery capacity from being lowered even under high temperature conditions, and to obtain good battery characteristics over a long period of time.
本発明においては、上記のような課題を解決するため、非水系溶媒に電解質のリチウム塩が含有された二次電池用非水電解液において、上記の非水系溶媒に、下記の式（１）に示したフッ素化鎖状カルボン酸エステルと、金属リチウムとリチウムイオンとの平衡電位を基準として＋１．０〜３．０Ｖの範囲で分解される被膜形成化合物とを含み、上記のフッ素化鎖状カルボン酸エステルが、非水系溶媒全体に対して２０〜８０体積％の範囲で含有されるようにした。
また、本発明においては、非水系溶媒に電解質のリチウム塩が含有され、上記の非水系溶媒に、下記の式（１）に示したフッ素化鎖状カルボン酸エステルと、金属リチウムとリチウムイオンとの平衡電位を基準として＋１．０〜３．０Ｖの範囲で分解される被膜形成化合物とを含み、上記の被膜形成化合物が、４−フルオロエチレンカーボネート、エチレンサルファイト、ビニルエチレンカーボネート、ＬｉＢ（Ｃ 2 Ｏ 4 ） 2 、ＬｉＢＦ 2 （Ｃ 2 Ｏ 4 ）から選択される少なくとも１種であるようにした。
Ｒ１−ＣＨ2−ＣＯＯ−Ｒ２ （１）
（式中、Ｒ１は水素又はアルキル基、Ｒ２はアルキル基を表し、Ｒ１とＲ２とにおける炭素数の和が３以内であり、Ｒ１が水素である場合には、Ｒ２における水素の少なくとも一部がフッ素で置換され、Ｒ１がアルキル基である場合には、Ｒ１及び／又はＲ２における水素の少なくとも一部がフッ素で置換されている。）
In the present invention, in order to solve the above-described problems, in the non-aqueous electrolyte for a secondary battery in which an electrolyte lithium salt is contained in the non-aqueous solvent, the non-aqueous solvent includes the following formula (1). a chain fluorinated carboxylic acid ester shown in, see containing a film forming compound which is decomposed in a range of + 1.0～3.0V the equilibrium potential as a reference between the metal lithium and lithium ions above fluorinated chains The carboxylic acid ester was contained in the range of 20 to 80% by volume with respect to the entire non-aqueous solvent .
In the present invention, the lithium salt of the electrolyte is contained in the non-aqueous solvent, and the fluorinated chain carboxylic acid ester represented by the following formula (1), metal lithium and lithium ion are contained in the non-aqueous solvent. A film-forming compound that is decomposed in the range of +1.0 to 3.0 V with respect to the equilibrium potential of the above, and the film-forming compound is composed of 4-fluoroethylene carbonate, ethylene sulfite, vinyl ethylene carbonate, LiB (C 2 O 4 ) 2 and LiBF 2 (C 2 O 4 ).
R1-CH 2 -COO-R2 ( 1)
(Wherein R1 represents hydrogen or an alkyl group, R2 represents an alkyl group, the sum of the carbon numbers in R1 and R2 is 3 or less, and when R1 is hydrogen, at least a part of the hydrogen in R2 is When substituted with fluorine and R1 is an alkyl group, at least a part of hydrogen in R1 and / or R2 is substituted with fluorine.)
このように、フッ素化鎖状カルボン酸エステルとして、上記のようにＲ１とＲ２とにおける炭素数の和が３以内のものを用いると、非水電解液の粘度が上昇して負荷特性が低下するのが防止されることを見出したのである。また、Ｒ１が水素である場合に、Ｒ２における水素の少なくとも一部がフッ素で置換され、Ｒ１がアルキル基である場合に、Ｒ１及び／又はＲ２における水素の少なくとも一部がフッ素で置換されたものを用いるようにすると、α炭素における水素がフッ素で置換されたフッ素化鎖状カルボン酸エステルを用いた場合における前記のような問題が生じないようになることを見出したのである。 As described above, when a fluorinated chain carboxylic acid ester having a sum of carbon numbers in R1 and R2 of 3 or less is used as described above, the viscosity of the nonaqueous electrolytic solution is increased and load characteristics are lowered. It was found that this was prevented. Further, when R1 is hydrogen, at least part of hydrogen in R2 is substituted with fluorine, and when R1 is an alkyl group, at least part of hydrogen in R1 and / or R2 is substituted with fluorine It has been found that the above-mentioned problems do not occur when a fluorinated chain carboxylic acid ester in which hydrogen at the α-carbon is substituted with fluorine is used.
そして、このようなフッ素化鎖状カルボン酸エステルとしては、３，３，３−トリフルオロプロピオン酸メチルＣＦ3ＣＨ2ＣＯＯＣＨ3と酢酸２，２，２−トリフルオロエチルＣＨ3ＣＯＯＣＨ2ＣＦ3とから選択される少なくとも１種を用いることが好ましい。特に、正極の電位が金属リチウム基準で４．３５Ｖ以上になるようにし、負極活物質に黒鉛系材料を用いた場合において、電池電圧が４．２５Ｖ以上になるまで充電させる場合には、フッ素化鎖状カルボン酸エステルとして、３，３，３−トリフルオロプロピオン酸メチルＣＦ3ＣＨ2ＣＯＯＣＨ3を用いることがより好ましい。
Such fluorinated chain carboxylic acid esters include methyl 3,3,3-trifluoropropionate CF 3 CH 2 COOCH 3 and
ここで、非水系溶媒中における上記のフッ素化鎖状カルボン酸エステルの量が少ないと、高温条件下における上記のような特性を十分に向上させることが困難になる一方、その量が多くなりすぎると、非水電解液中に含有させる上記の被膜形成化合物の量が減少して、負極に十分な被膜が形成されなくなるため、上記のフッ素化鎖状カルボン酸エステルの量を、非水系溶媒全体に対して５〜９０体積％の範囲にすることが好ましく、特に、２０〜８０体積％の範囲にすることがより好ましい。 Here, if the amount of the fluorinated chain carboxylic acid ester in the non-aqueous solvent is small, it becomes difficult to sufficiently improve the above characteristics under high temperature conditions, while the amount is too large. And the amount of the film-forming compound contained in the non-aqueous electrolyte is reduced, and a sufficient film is not formed on the negative electrode. Therefore, the amount of the fluorinated chain carboxylic acid ester is reduced to the whole non-aqueous solvent. It is preferable to make it into the range of 5 to 90 volume% with respect to it, and it is more preferable to set it as the range of 20 to 80 volume% especially.
また、上記のように金属リチウムとリチウムイオンとの平衡電位を基準として、＋１．０〜３．０Ｖの範囲で分解される被膜形成化合物を含有させると、上記のフッ素化鎖状カルボン酸エステルが負極と反応して分解するのが抑制され、或いはこのフッ素化鎖状カルボン酸エステルが負極の被膜形成に部分的に関与し、過大に分解するのが抑制される。 Moreover, when the film-forming compound that is decomposed in the range of +1.0 to 3.0 V is contained on the basis of the equilibrium potential between metallic lithium and lithium ions as described above, the fluorinated chain carboxylic acid ester becomes The reaction with the negative electrode is inhibited from being decomposed, or the fluorinated chain carboxylic acid ester is partially involved in the formation of the negative electrode film, and is prevented from being excessively decomposed.
例えば、上記のフッ素化鎖状カルボン酸エステルであるＣＦ3ＣＨ2ＣＯＯＣＨ3やＣＨ3ＣＯＯＣＨ2ＣＦ3に対して１ｍｏｌ／ｌとなるようＬｉＰＦ6を溶解させ、黒鉛負極を作用電極として用い、走査速度１ｍＶ／ｓｅｃの測定条件にてＣＶ測定した場合、金属リチウムとリチウムイオンとの平衡電位に対して、ＣＦ3ＣＨ2ＣＯＯＣＨ3の場合には＋１．２Ｖ程度、ＣＨ3ＣＯＯＣＨ2ＣＦ3の場合には＋０．８Ｖ程度で還元分解される。このため、＋１．０Ｖ以上で分解する被膜形成化合物を含有させることで、上記のフッ素化鎖状カルボン酸エステルが負極と反応して分解するのを抑制することができ、或いはこのフッ素化鎖状カルボン酸エステルが負極の被膜形成に部分的に関与し、過大に分解するのを抑制することができる。また、非水電解液を注液した時の黒鉛負極の電位は＋３．０Ｖ程度であるため、＋３．０Ｖ以下で分解する被膜形成化合物を含有させる必要がある。 For example, LiPF 6 is dissolved so as to be 1 mol / l with respect to CF 3 CH 2 COOCH 3 and CH 3 COOCH 2 CF 3 which are the above fluorinated chain carboxylic acid esters, a graphite negative electrode is used as a working electrode, and scanning is performed. When CV measurement is performed under a measurement condition of a speed of 1 mV / sec, about 1.2 V in the case of CF 3 CH 2 COOCH 3 and CH 3 COOCH 2 CF 3 with respect to the equilibrium potential between lithium metal and lithium ions. In the case of, it is reductively decomposed at about + 0.8V . For this reason, by containing a film-forming compound that decomposes at +1.0 V or more, the above fluorinated chain carboxylic acid ester can be prevented from being decomposed by reacting with the negative electrode, or the fluorinated chain form. It is possible to suppress the carboxylic acid ester from being partly involved in the formation of the negative electrode film and being excessively decomposed. Further, since the potential of the graphite negative electrode when the nonaqueous electrolyte is injected is about +3.0 V, it is necessary to contain a film forming compound that decomposes at +3.0 V or less.
そして、上記のような被膜形成化合物を含有させることにより、フッ素化鎖状カルボン酸エステルと負極との反応を抑制でき、またフッ素化鎖状カルボン酸エステルを溶媒に用いることで正極との反応を抑制でき、良好な電池特性を得ることができる。 By containing the film forming compound as described above, the reaction between the fluorinated chain carboxylic acid ester and the negative electrode can be suppressed, and the reaction with the positive electrode can be performed by using the fluorinated chain carboxylic acid ester as a solvent. It can suppress and can obtain a favorable battery characteristic.
そして、上記のような被膜形成化合物としては、例えば、４−フルオロエチレンカーボネート、エチレンサルファイト、ビニルエチレンカーボネート、ＬｉＢ（Ｃ2Ｏ4）2、ＬｉＢＦ2（Ｃ2Ｏ4）から選択される少なくとも１種を用いることができ、特に、負極に適切な被膜を形成すると共に非水系溶媒として有効に機能する４−フルオロエチレンカーボネートを用いることが好ましい。ここで、金属リチウムとリチウムイオンとの平衡電位を基準として分解される電位は、４−フルオロエチレンカーボネートでは約１．２Ｖ、エチレンサルファイトでは約１．１Ｖ、ビニルエチレンカーボネートでは約１．３Ｖ、ＬｉＢ（Ｃ2Ｏ4）2では約２．０Ｖ、ＬｉＢＦ2（Ｃ2Ｏ4）では約１．７Ｖである。また、４−フルオロエチレンカーボネートの誘導体、エチレンサルファイトの誘導体、ビニルエチレンカーボネートの誘導体としても、金属リチウムとリチウムイオンとの平衡電位を基準として分解される電位が＋１．０〜３．０Ｖの範囲のものを用い、好ましくは＋１．１〜２．０Ｖの範囲のものを用いるようにする。 The film-forming compound as described above is, for example, at least selected from 4-fluoroethylene carbonate, ethylene sulfite, vinyl ethylene carbonate, LiB (C 2 O 4 ) 2 , LiBF 2 (C 2 O 4 ). One type can be used, and it is particularly preferable to use 4-fluoroethylene carbonate which forms an appropriate film on the negative electrode and functions effectively as a non-aqueous solvent. Here, the potential decomposed on the basis of the equilibrium potential between lithium metal and lithium ions is about 1.2 V for 4-fluoroethylene carbonate, about 1.1 V for ethylene sulfite, about 1.3 V for vinyl ethylene carbonate, In LiB (C 2 O 4 ) 2 , it is about 2.0 V, and in LiBF 2 (C 2 O 4 ), it is about 1.7 V. Further, as a derivative of 4-fluoroethylene carbonate, a derivative of ethylene sulfite, and a derivative of vinyl ethylene carbonate, the potential decomposed on the basis of the equilibrium potential between metallic lithium and lithium ions is in the range of +1.0 to 3.0 V. And preferably those in the range of +1.1 to 2.0V.
そして、上記の被膜形成化合物として４−フルオロエチレンカーボネートを非水系溶媒に含有させる場合、４−フルオロエチレンカーボネートの量が少ないと、負極に十分な被膜が形成されず、フッ素化鎖状カルボン酸エステルが還元分解されて、非水電解液二次電池を充電状態で高温条件下において放置させた場合における保存特性が低下する。一方、４−フルオロエチレンカーボネートの量が多くなり過ぎると、非水電解液の粘度が上昇して負荷特性が低下する。このため、４−フルオロエチレンカーボネートの量を非水系溶媒全体に対して２〜４０体積％の範囲にすることが好ましく、特に、５〜３０体積％の範囲にすることがより好ましい。 When 4-fluoroethylene carbonate is contained in the non-aqueous solvent as the film forming compound, if the amount of 4-fluoroethylene carbonate is small, a sufficient film is not formed on the negative electrode, and the fluorinated chain carboxylic acid ester is formed. Is reduced and the storage characteristics of the non-aqueous electrolyte secondary battery when it is allowed to stand in a charged state under high temperature conditions deteriorate. On the other hand, when the amount of 4-fluoroethylene carbonate is too large, the viscosity of the non-aqueous electrolyte is increased and the load characteristics are lowered. For this reason, it is preferable to make the quantity of 4-fluoroethylene carbonate into the range of 2-40 volume% with respect to the whole non-aqueous solvent, and it is more preferable to set it as the range of 5-30 volume% especially.
また、被膜形成化合物として、エチレンサルファイト及びその誘導体、ビニルエチレンカーボネート及びその誘導体を用いる場合には、その含有量が電解質を含めた非水電解液の総量に対して０．１〜１０重量％、特に０．２〜５重量％の範囲になるようにすることが好ましい。また、ＬｉＢ（Ｃ2Ｏ4）2やＬｉＢＦ2（Ｃ2Ｏ4）からなるＬｉ塩を被膜形成化合物として用いる場合には、その含有量が非水系溶媒に対して０．０１〜０．４ｍｏｌ／ｌ、特に０．０５〜０．２ｍｏｌ／ｌの範囲になるようにすることが好ましい。これは、これらの被膜形成化合物の量が、上記の範囲より少なくなると、負極に十分な被膜が形成されず、フッ素化鎖状カルボン酸エステルが還元分解されて、良好な高温充電保存特性が得られなくなる一方、上記の範囲より多くなると、これらの被膜形成化合物の分解が顕著に起こり、内部抵抗の増加やガス発生を引き起こすおそれがあるためである。 Further, when ethylene sulfite and derivatives thereof, vinyl ethylene carbonate and derivatives thereof are used as the film forming compound, the content thereof is 0.1 to 10% by weight with respect to the total amount of the nonaqueous electrolytic solution including the electrolyte. In particular, it is preferable to be in the range of 0.2 to 5% by weight. In the case of using the Li salt film forming compound consisting LiB (C 2 O 4) 2 or LiBF 2 (C 2 O 4) is, 0.01～0.4Mol its content relative to the non-aqueous solvent / L, particularly 0.05 to 0.2 mol / l. This is because when the amount of these film-forming compounds is less than the above range, a sufficient film is not formed on the negative electrode, and the fluorinated chain carboxylic acid ester is reduced and decomposed to obtain good high-temperature charge storage characteristics. On the other hand, if it exceeds the above range, these film-forming compounds are significantly decomposed, which may cause an increase in internal resistance and gas generation.
また、上記の二次電池用非水電解液においては、上記の非水系溶媒に、上記のフッ素化鎖状カルボン酸エステルと被膜形成化合物との他に、他の非水系溶媒を加えることも可能であり、このような非水系溶媒としては、例えば、ジメチルカーボネートＣＨ3ＯＣＯＯＣＨ3、エチルメチルカーボネートＣＨ3ＯＣＯＯＣ2Ｈ5、ジエチルカーボネートＣ2Ｈ5ＯＣＯＯＣ2Ｈ5、酢酸メチルＣＨ3ＣＯＯＣＨ3、プロピオン酸メチルＣ2Ｈ5ＣＯＯＣＨ3、酢酸エチルＣＨ3ＣＯＯＣ2Ｈ5等を用いることが好ましく、特に、非水電解液の粘度を低減させて負荷特性を向上させるためには、酢酸メチル、プロピオン酸メチル、酢酸エチル、ジメチルカーボネートから選択される少なくとも１種の低粘度溶媒を加えることが好ましい。さらに、非水電解液の導電率を高めるために、高誘電率溶媒であるエチレンカーボネート、プロピレンカーボネート、γ−ブチロラクトン等を混合させることも可能である。 In the non-aqueous electrolyte for secondary battery, other non-aqueous solvent can be added to the non-aqueous solvent in addition to the fluorinated chain carboxylic acid ester and the film-forming compound. and a, as such non-aqueous solvents, e.g., dimethyl carbonate CH 3 OCOOCH 3, ethylmethyl carbonate CH 3 OCOOC 2 H 5, diethyl carbonate C 2 H 5 OCOOC 2 H 5 , methyl acetate CH 3 COOCH 3, propionic It is preferable to use methyl acid C 2 H 5 COOCH 3 , ethyl acetate CH 3 COOC 2 H 5, etc. In particular, in order to reduce the viscosity of the non-aqueous electrolyte and improve the load characteristics, methyl acetate, propionic acid It is preferable to add at least one low viscosity solvent selected from methyl, ethyl acetate and dimethyl carbonate. Furthermore, in order to increase the electrical conductivity of the non-aqueous electrolyte, it is also possible to mix ethylene carbonate, propylene carbonate, γ-butyrolactone, etc., which are high dielectric constant solvents.
また、上記の二次電池用非水電解液において、上記の非水系溶媒に溶解させるリチウム塩からなる電解質としては、上記の被膜形成化合物として用いるＬｉＢ（Ｃ2Ｏ4）2やＬｉＢＦ2（Ｃ2Ｏ4）に加えて、非水電解液二次電池において一般に使用されているリチウム塩を用いることができる。そして、上記のリチウム塩としては、例えば、ＬｉＰＦ6，ＬｉＢＦ4，ＬｉＣＦ3ＳＯ3，ＬｉＣｌＯ4，ＬｉＮ（ＣＦ3ＳＯ2）2，ＬｉＮ（Ｃ2Ｆ5ＳＯ2）2，ＬｉＮ（ＣＦ3ＳＯ2）（Ｃ4Ｆ9ＳＯ2），ＬｉＣ（ＣＦ3ＳＯ2）3，ＬｉＣ（Ｃ2Ｆ5ＳＯ2）3等を用いることができ、特にＬｉＰＦ6，ＬｉＢＦ4，ＬｉＮ（ＣＦ3ＳＯ2）2を用いることが好ましい。 In the non-aqueous electrolyte for a secondary battery, the electrolyte made of a lithium salt dissolved in the non-aqueous solvent may be LiB (C 2 O 4 ) 2 or LiBF 2 (C In addition to 2 O 4 ), lithium salts generally used in non-aqueous electrolyte secondary batteries can be used. Examples of the lithium salt include LiPF 6 , LiBF 4 , LiCF 3 SO 3 , LiClO 4 , LiN (CF 3 SO 2 ) 2 , LiN (C 2 F 5 SO 2 ) 2 , LiN (CF 3 SO 2 ) (C 4 F 9 SO 2 ), LiC (CF 3 SO 2 ) 3 , LiC (C 2 F 5 SO 2 ) 3, etc. can be used, especially LiPF 6 , LiBF 4 , LiN (CF 3 SO 2). It is preferable to use 2 .
また、本発明における非水電解液二次電池においては、非水電解液として、上記のような二次電池用非水電解液を用いるようにした。 In the non-aqueous electrolyte secondary battery according to the present invention, the non-aqueous electrolyte for a secondary battery as described above is used as the non-aqueous electrolyte.
ここで、この非水電解液二次電池の正極に用いる正極活物質としては、リチウムを吸蔵、放出することができ、その電位が貴な材料であれば特に限定されず、一般に使用されている公知の正極活物質を用いることができ、例えば、層状構造や、スピネル型構造や、オリビン型構造を有するリチウム遷移金属複合酸化物を単独又は複数組み合わせて使用することができる。特に、高エネルギー密度の非水電解液二次電池を得るためには、層状構造を有するリチウム遷移金属複合酸化物を用いることが好ましく、具体的には、リチウム・コバルト複合酸化物、リチウム・コバルト・ニッケル・マンガン複合酸化物、リチウム・コバルト・ニッケル・アルミニウム複合酸化物からなるリチウム遷移金属複合酸化物を用いることが好ましい。特に、結晶構造の安定性の観点からは、Ａｌ或いはＭｇが結晶内部に固溶され、かつＺｒが粒子表面に固着したコバルト酸リチウムを用いることが好ましい。 Here, the positive electrode active material used for the positive electrode of the non-aqueous electrolyte secondary battery is not particularly limited as long as it is a material that can occlude and release lithium and has a noble potential, and is generally used. A known positive electrode active material can be used. For example, lithium transition metal composite oxides having a layered structure, a spinel structure, or an olivine structure can be used singly or in combination. In particular, in order to obtain a high energy density non-aqueous electrolyte secondary battery, it is preferable to use a lithium transition metal composite oxide having a layered structure. Specifically, lithium-cobalt composite oxide, lithium-cobalt It is preferable to use a lithium / transition metal composite oxide composed of nickel / manganese composite oxide or lithium / cobalt / nickel / aluminum composite oxide. In particular, from the viewpoint of the stability of the crystal structure, it is preferable to use lithium cobalt oxide in which Al or Mg is dissolved in the crystal and Zr is fixed to the particle surface.
また、この非水電解液二次電池の負極に用いる負極活物質としては、リチウムを吸蔵、放出することができる材料であれば特に限定されず、一般に使用されている公知の負極活物質を用いることができ、例えば、金属リチウム、リチウム−アルミニウム合金，リチウム−鉛合金，リチウム−シリコン合金，リチウム−スズ合金等のリチウム合金、黒鉛，コークス，有機物焼成体等の炭素材料、ＳｎＯ2、ＳｎＯ、ＴｉＯ2等の電位が正極活物質に比べて卑な金属酸化物を用いることができ、特に、リチウムの吸蔵、放出に伴う体積変化が少なくて可逆性に優れる黒鉛系の炭素材料を用いることが好ましい。 The negative electrode active material used for the negative electrode of the non-aqueous electrolyte secondary battery is not particularly limited as long as it is a material capable of occluding and releasing lithium, and a commonly used negative electrode active material is used. For example, lithium materials such as metallic lithium, lithium-aluminum alloy, lithium-lead alloy, lithium-silicon alloy, lithium-tin alloy, carbon materials such as graphite, coke, fired organic matter, SnO 2 , SnO, It is possible to use a metal oxide whose base potential is lower than that of the positive electrode active material, such as TiO 2 , and in particular, to use a graphite-based carbon material that is excellent in reversibility with little volume change due to insertion and extraction of lithium. preferable.
本発明においては、非水系溶媒に電解質のリチウム塩が含有された二次電池用非水電解液に、上記の式（１）に示したフッ素化鎖状カルボン酸エステルと、金属リチウムとリチウムイオンとの平衡電位を基準として＋１．０〜３．０Ｖの範囲で分解される被膜形成化合物とを含む非水系溶媒を用いるようにした。 In the present invention, a non-aqueous electrolyte for a secondary battery containing a lithium salt of an electrolyte in a non-aqueous solvent is added to the fluorinated chain carboxylic acid ester represented by the above formula (1), lithium metal and lithium ion. And a non-aqueous solvent containing a film-forming compound that is decomposed in the range of +1.0 to 3.0 V with respect to the equilibrium potential.
この結果、このような非水電解液を用いた非水電解液二次電池においては、上記の被膜形成化合物により負極に適切な被膜が形成されて、上記のフッ素化鎖状カルボン酸エステルが分解するのが抑制され、高温条件下においても電池容量が低下するのが抑制されて、良好な電池特性が得られるようになった。 As a result, in a non-aqueous electrolyte secondary battery using such a non-aqueous electrolyte, an appropriate film is formed on the negative electrode by the film-forming compound, and the fluorinated chain carboxylic acid ester is decomposed. Therefore, the battery capacity is prevented from decreasing even under high temperature conditions, and good battery characteristics can be obtained.
次に、本発明に係る二次電池用非水電解液を用いた非水電解液二次電池について実施例を挙げて具体的に説明すると共に、本発明の非水電解液二次電池は、高容量化させた場合においても高温での保存特性が向上することを、比較例を挙げて明らかにする。 Next, the non-aqueous electrolyte secondary battery using the non-aqueous electrolyte for a secondary battery according to the present invention will be specifically described with reference to examples, and the non-aqueous electrolyte secondary battery of the present invention includes: It will be clarified by a comparative example that the storage characteristics at high temperatures are improved even when the capacity is increased.
（実施例１）
実施例１においては、下記のようにして作製した正極と負極と非水電解液とを用い、図１に示すような円筒型で、充電終止電圧が４．２Ｖ、設計容量が２３００ｍＡｈの非水電解液二次電池を作製した。
Example 1
In Example 1, using a positive electrode, a negative electrode, and a non-aqueous electrolyte prepared as follows, a cylindrical shape as shown in FIG. 1, a non-aqueous battery with a charge end voltage of 4.2 V and a design capacity of 2300 mAh is used. An electrolyte secondary battery was produced.
［正極の作製］
正極を作製するにあたっては、正極活物質として、コバルト酸リチウムＬｉＣｏＯ2にＡｌとＭｇとがそれぞれ１．０ｍｏｌ％固溶されると共にその固溶体の粒子表面にＺｒが０．０５ｍｏｌ％付与されたものを用いた。
[Production of positive electrode]
In producing the positive electrode, as the positive electrode active material, 1.0 mol% of Al and Mg were respectively dissolved in lithium cobalt oxide LiCoO 2 and 0.05 mol% of Zr was added to the particle surface of the solid solution. Using.
そして、この正極活物質と、導電剤の炭素と、結着剤のポリフッ化ビニリデンとが９５：２．５：２．５の重量比になるようにして、これらをＮ−メチル−２−ピロリドン溶液中で混練して正極合剤スラリーを作製した。次いで、この正極合剤スラリーをアルミニウム箔からなる正極集電体の両面に塗布し、これを乾燥させた後、圧延させて正極を作製した。 Then, the positive electrode active material, the carbon of the conductive agent, and the polyvinylidene fluoride as the binder were in a weight ratio of 95: 2.5: 2.5, and these were converted to N-methyl-2-pyrrolidone. A positive electrode mixture slurry was prepared by kneading in a solution. Next, this positive electrode mixture slurry was applied to both surfaces of a positive electrode current collector made of aluminum foil, dried, and then rolled to produce a positive electrode.
［負極の作製］
負極を作製するにあたっては、負極活物質の黒鉛と、結着剤のスチレン・ブタジエンゴムと、増粘剤のカルボキシメチルセルロースとを９７．５：１．５：１の重量比になるようにして、これらを水溶液中において混練して負極合剤スラリーを作製した。そして、この負極合剤スラリーを銅箔からなる負極集電体の両面に塗布させ、これを乾燥させた後、圧延させて負極を作製した。
[Production of negative electrode]
In producing the negative electrode, the negative electrode active material graphite, the binder styrene-butadiene rubber, and the thickener carboxymethyl cellulose in a weight ratio of 97.5: 1.5: 1, These were kneaded in an aqueous solution to prepare a negative electrode mixture slurry. And this negative electrode mixture slurry was apply | coated on both surfaces of the negative electrode collector which consists of copper foils, and after drying this, it rolled and produced the negative electrode.
［非水電解液の作製］
非水電解液を作製するにあたっては、非水系溶媒として、金属リチウムとリチウムイオンとの平衡電位を基準とした分解電位が１．０〜３．０Ｖの範囲にある被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＦ3ＣＨ2ＣＯＯＣＨ3とを２：８の体積比で混合させた混合溶媒を用いた。そして、この混合溶媒に電解質としてヘキサフルオロリン酸リチウムＬｉＰＦ6を１ｍｏｌ／ｌの割合で溶解させて、非水電解液を作製した。
[Preparation of non-aqueous electrolyte]
In preparing the non-aqueous electrolyte, as the non-aqueous solvent, 4-fluoroethylene, a film-forming compound having a decomposition potential in the range of 1.0 to 3.0 V based on the equilibrium potential of metallic lithium and lithium ions. A mixed solvent in which carbonate (4-FEC) and CF 3 CH 2 COOCH 3 which is a fluorinated chain carboxylic acid ester represented by the above formula (1) were mixed at a volume ratio of 2: 8 was used. Then, lithium hexafluorophosphate LiPF 6 as an electrolyte was dissolved in this mixed solvent at a rate of 1 mol / l to prepare a nonaqueous electrolytic solution.
ここで、フッ素化鎖状カルボン酸エステルとして用いた上記のＣＦ3ＣＨ2ＣＯＯＣＨ3（３，３，３−トリフルオロプロピオン酸メチル）の合成方法を下記に示す。 Here, a method for synthesizing the above CF 3 CH 2 COOCH 3 (methyl 3,3,3-trifluoropropionate) used as the fluorinated chain carboxylic acid ester is shown below.
１リットルのナス型フラスコに、ジイソプロピルアミン３５ｇ（３５０ｍｍｏｌ）とテトラヒドロフラン３００ｍｌとを仕込み、氷冷、攪拌しながら、１．６Ｍノルマルブチルリチウム／ヘキサン２１９ｍｌ（３５０ｍｍｏｌ）を徐々に滴下し、更に室温で３０分間攪拌してリチウムジイソプロピルアミドを調製した。次いで、このリチウムジイソプロピルアミド溶液を−８０℃に冷却し、メチルアセテート２６ｇ（３５０ｍｍｏｌ）を徐々に滴下して、１５分間熟成した後に、クロロトリメチルシラン３８ｇ（３５０ｍｍｏｌ）を加えてクエンチし、室温で一晩攪拌した。そして、生成した固体を濾別した後、溶媒を留去して得た黄色のオイルをノルマルヘキサン２００ｍｌに溶解し、−７８℃に冷却し、攪拌しながらヨードトリフルオロメタン７０ｇ（３６０ｍｍｏｌ）を加えた。そして、１Ｍトリエチルボラン／ヘキサン１０ｍｌ（１０ｍｍｏｌ）を加え、約２時間で室温まで昇温した。次いで、水２００ｍｌを加えてクエンチした後、分液ロートにより有機層を分離し、硝酸マグネシウムで乾燥させた。その後、蒸留により精製を行い、３，３，３−トリフルオロプロピオン酸メチルを１０ｇ（収率２０％）得た。 Into a 1 liter eggplant type flask, 35 g (350 mmol) of diisopropylamine and 300 ml of tetrahydrofuran were charged, and 219 ml (350 mmol) of 1.6 M normal butyllithium / hexane was gradually added dropwise with ice cooling and stirring. Lithium diisopropylamide was prepared by stirring for minutes. Next, this lithium diisopropylamide solution was cooled to −80 ° C., 26 g (350 mmol) of methyl acetate was gradually added dropwise, and after aging for 15 minutes, it was quenched by adding 38 g (350 mmol) of chlorotrimethylsilane at room temperature. Stir overnight. And after filtering off the produced | generated solid, the yellow oil obtained by distilling a solvent off was melt | dissolved in 200 ml of normal hexane, it cooled at -78 degreeC, and 70 g (360 mmol) of iodotrifluoromethane was added, stirring. . Then, 10 ml (10 mmol) of 1M triethylborane / hexane was added, and the temperature was raised to room temperature in about 2 hours. Subsequently, after quenching by adding 200 ml of water, the organic layer was separated with a separatory funnel and dried over magnesium nitrate. Thereafter, purification was performed by distillation to obtain 10 g (yield 20%) of methyl 3,3,3-trifluoropropionate.
そして、この実施例の非水電解液二次電池を作製するにあたっては、図１に示すように、上記のようにして作製した正極１と負極２との間に、セパレータ３としてリチウムイオン透過性のポリエチレン製の微多孔膜を介在させ、これらをスパイラル状に巻いて電池缶４内に収容させた後、この電池缶４内に上記の非水電解液を注液して封口し、上記の正極１を正極タブ５により、正極蓋６に取り付けられた正極外部端子９に接続させると共に、上記の負極２を負極タブ７により電池缶４に接続させ、電池缶４と正極蓋６とを絶縁パッキン８により電気的に分離させた。
And in producing the non-aqueous electrolyte secondary battery of this example, as shown in FIG. 1, lithium ion permeable as a separator 3 between the
（実施例２）
実施例２においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＨ3ＣＯＯＣＨ2ＣＦ3とを２：８の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Example 2)
In Example 2, in preparation of the non-aqueous electrolyte in Example 1 above, as the non-aqueous solvent, 4-fluoroethylene carbonate (4-FEC), which is the same film-forming compound as in Example 1, and the above formula ( A mixed solvent prepared by mixing CH 3 COOCH 2 CF 3 which is a fluorinated chain carboxylic acid ester shown in 1) at a volume ratio of 2: 8 is used, and other than that, the same as in the case of Example 1 above. Thus, a non-aqueous electrolyte secondary battery was produced.
ここで、フッ素化鎖状カルボン酸エステルとして用いた上記のＣＨ3ＣＯＯＣＨ2ＣＦ3（酢酸２，２，２−トリフルオロエチル）の合成方法を下記に示す。
Here, a synthesis method of the above-mentioned CH 3 COOCH 2 CF 3 (
１リットルのセパラブルフラスコに、トリフルオロエタノール８５ｇ（０．８５ｍｏｌ）とジエチルエーテル８０ｍｌとを仕込み、さらにトリエチルアミン１２９ｇ（１．２７ｍｏｌ／１．５ｅｑ）を加えた。そして、これを氷冷、攪拌しながら、アセチルクロリド１００ｇ（１．２７ｍｏｌ／１．５ｅｑ）をジエチルエーテル８０ｍｌで希釈した液を、滴下ロートにて滴下した。反応液の温度が２７〜３５℃になるように滴下し、２０分間で終了した。その後、室温で１．５時間攪拌した後、水３５０ｍｌを加えて反応を終了した。次いで、分液ロートにより有機層を分離し、硝酸マグネシウムで乾燥させた後、蒸留により精製を行い、酢酸２，２，２−トリフルオロエチルを８８ｇ（収率７３％）得た。 A 1 liter separable flask was charged with 85 g (0.85 mol ) of trifluoroethanol and 80 ml of diethyl ether, and 129 g (1.27 mol / 1.5 eq) of triethylamine was further added. Then, a solution obtained by diluting 100 g (1.27 mol / 1.5 eq) of acetyl chloride with 80 ml of diethyl ether was dropped with a dropping funnel while cooling with ice and stirring. The reaction solution was added dropwise so that the temperature was 27 to 35 ° C., and the reaction was completed in 20 minutes. Then, after stirring at room temperature for 1.5 hours, 350 ml of water was added to complete the reaction. Next, the organic layer was separated with a separatory funnel, dried over magnesium nitrate, and purified by distillation to obtain 88 g (yield 73%) of 2,2,2-trifluoroethyl acetate.
（実施例３）
実施例３においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＦ3ＣＨ2ＣＯＯＣＨ3とを１：９の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Example 3)
In Example 3, in the preparation of the non-aqueous electrolyte in Example 1 above, as the non-aqueous solvent, 4-fluoroethylene carbonate (4-FEC), which is the same film-forming compound as in Example 1, and the above formula ( A mixed solvent obtained by mixing CF 3 CH 2 COOCH 3 which is a fluorinated chain carboxylic acid ester shown in 1) at a volume ratio of 1: 9 is used, and other than that, the same as in the case of Example 1 above. Thus, a non-aqueous electrolyte secondary battery was produced.
（実施例４）
実施例４においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＦ3ＣＨ2ＣＯＯＣＨ3とを３：７の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
Example 4
In Example 4, in the preparation of the non-aqueous electrolyte in Example 1 above, as the non-aqueous solvent, 4-fluoroethylene carbonate (4-FEC), which is the same film-forming compound as in Example 1, and the above formula ( A mixed solvent prepared by mixing CF 3 CH 2 COOCH 3 which is a fluorinated chain carboxylic acid ester shown in 1) at a volume ratio of 3: 7 is used, and other than that, the same as in the case of Example 1 above. Thus, a non-aqueous electrolyte secondary battery was produced.
（実施例５）
実施例５においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＦ3ＣＨ2ＣＯＯＣＨ3と、ジメチルカーボネート（ＤＭＣ）を２：４：４の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Example 5)
In Example 5, in the preparation of the non-aqueous electrolyte in Example 1 above, as the non-aqueous solvent, 4-fluoroethylene carbonate (4-FEC), which is the same film-forming compound as in Example 1, and the above formula ( A mixed solvent in which CF 3 CH 2 COOCH 3 which is a fluorinated chain carboxylic acid ester shown in 1) and dimethyl carbonate (DMC) are mixed at a volume ratio of 2: 4: 4 is used. A non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1.
（実施例６）
実施例６においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＦ3ＣＨ2ＣＯＯＣＨ3と、フッ素化されていない鎖状カルボン酸エステルであるプロピオン酸メチルＣＨ3ＣＨ2ＣＯＯＣＨ3を２：４：４の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Example 6)
In Example 6, in the preparation of the non-aqueous electrolyte in Example 1 above, as the non-aqueous solvent, 4-fluoroethylene carbonate (4-FEC), which is the same film-forming compound as in Example 1, and the above formula ( CF 3 CH 2 COOCH 3 which is a fluorinated chain carboxylic acid ester shown in 1) and methyl propionate CH 3 CH 2 COOCH 3 which is a non-fluorinated chain carboxylic acid ester are in a ratio of 2: 4: 4. A non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1 except that a mixed solvent mixed at a volume ratio was used.
（比較例１）
比較例１においては、非水系溶媒として、エチレンカーボネート（ＥＣ）とエチルメチルカーボネート（ＥＭＣ）とを３：７の体積比で混合させた混合溶媒を用い、この混合溶媒に電解質としてヘキサフルオロリン酸リチウムＬｉＰＦ6を１ｍｏｌ／ｌの割合で溶解させ、これに対してビニレンカーボネート（ＶＣ）を２重量％の割合で添加した非水電解液を用いた。そして、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Comparative Example 1)
In Comparative Example 1, a mixed solvent in which ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed at a volume ratio of 3: 7 was used as a non-aqueous solvent, and hexafluorophosphoric acid was used as an electrolyte in the mixed solvent. Lithium LiPF 6 was dissolved at a rate of 1 mol / l, and a nonaqueous electrolytic solution to which vinylene carbonate (VC) was added at a rate of 2% by weight was used. Other than that, a non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1 above.
（比較例２）
比較例２においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、フッ素化されていない鎖状カルボン酸エステルであるプロピオン酸メチルＣＨ3ＣＨ2ＣＯＯＣＨ3とを２：８の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Comparative Example 2)
In Comparative Example 2, in the preparation of the nonaqueous electrolytic solution in Example 1 above, 4-fluoroethylene carbonate (4-FEC), which is the same film forming compound as Example 1, was fluorinated as a nonaqueous solvent. Non-chain carboxylic acid ester methyl propionate CH 3 CH 2 COOCH 3 was used in the same manner as in Example 1 above, except that a mixed solvent in which the mixture was mixed at a volume ratio of 2: 8 was used. A water electrolyte secondary battery was produced.
（比較例３）
比較例３においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、フッ素化を行っていない鎖状カルボン酸エステルであるＣＨ3ＣＯＯＣＨ2ＣＨ3とを２：８の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Comparative Example 3)
In Comparative Example 3, in the preparation of the non-aqueous electrolyte in Example 1 above, fluorination was performed with 4-fluoroethylene carbonate (4-FEC), which is the same film-forming compound as Example 1, as the non-aqueous solvent. Non-aqueous electrolysis is performed in the same manner as in Example 1 except that a mixed solvent in which CH 3 COOCH 2 CH 3 which is a non-chain carboxylic acid ester is mixed at a volume ratio of 2: 8 is used. A liquid secondary battery was produced.
（比較例４）
比較例４においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、α炭素における水素がフッ素で置換されたフッ素化鎖状カルボン酸エステルであるＣＨＦ2ＣＯＯＣＨ2ＣＨ3とを２：８の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Comparative Example 4)
In Comparative Example 4, in the preparation of the nonaqueous electrolytic solution in Example 1 above, 4-fluoroethylene carbonate (4-FEC), which is the same film-forming compound as in Example 1, was used as the nonaqueous solvent, and hydrogen at the α-carbon. A mixed solvent prepared by mixing CHF 2 COOCH 2 CH 3 , which is a fluorinated chain carboxylic acid ester substituted with fluorine, at a volume ratio of 2: 8, and otherwise, Similarly, a non-aqueous electrolyte secondary battery was produced.
（比較例５）
比較例５においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、α炭素における水素がフッ素で置換されたフッ素化鎖状カルボン酸エステルであるＣＨＦ2ＣＯＯＣＨ3とを２：８の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Comparative Example 5)
In Comparative Example 5, in the preparation of the non-aqueous electrolyte in Example 1 above, 4-fluoroethylene carbonate (4-FEC), which is the same film-forming compound as Example 1, and hydrogen in α-carbon were used as the non-aqueous solvent. In the same manner as in Example 1 above, except that a mixed solvent in which CHF 2 COOCH 3 which is a fluorinated chain carboxylic acid ester substituted with fluorine is mixed at a volume ratio of 2: 8 is used. Thus, a non-aqueous electrolyte secondary battery was produced.
（比較例６）
比較例６においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、金属リチウムとリチウムイオンとの平衡電位を基準とした分解電位が１．０〜３．０Ｖの範囲外の０．６Ｖであるエチレンカーボネートと、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＦ3ＣＨ2ＣＯＯＣＨ3とを２：８の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Comparative Example 6)
In Comparative Example 6, in the preparation of the non-aqueous electrolyte in Example 1 above, the decomposition potential based on the equilibrium potential of metallic lithium and lithium ions as a non-aqueous solvent is in the range of 1.0 to 3.0 V. A mixed solvent prepared by mixing ethylene carbonate of 0.6 V outside and CF 3 CH 2 COOCH 3 which is a fluorinated chain carboxylic acid ester represented by the above formula (1) in a volume ratio of 2: 8. Otherwise, a non-aqueous electrolyte secondary battery was fabricated in the same manner as in Example 1 above.
（比較例７）
比較例７においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、金属リチウムとリチウムイオンとの平衡電位を基準とした分解電位が１．０〜３．０Ｖの範囲外の０．６Ｖであるエチレンカーボネートと、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＨ3ＣＯＯＣＨ2ＣＦ3とを２：８の体積比で混合させた混合溶媒を用い、それ以外は、上記の実施例１の場合と同様にして非水電解液二次電池を作製した。
(Comparative Example 7)
In Comparative Example 7, in the preparation of the nonaqueous electrolytic solution in Example 1, the decomposition potential based on the equilibrium potential of metallic lithium and lithium ions as a nonaqueous solvent is in the range of 1.0 to 3.0 V. A mixed solvent prepared by mixing ethylene carbonate having an external voltage of 0.6 V and CH 3 COOCH 2 CF 3 , which is a fluorinated chain carboxylic acid ester represented by the above formula (1), at a volume ratio of 2: 8. Otherwise, a non-aqueous electrolyte secondary battery was fabricated in the same manner as in Example 1 above.
そして、上記のように作製した実施例１〜６及び比較例１〜７の各非水電解液二次電池を、それぞれ２５℃において、４６０ｍＡの定電流で４．２Ｖになるまで充電し、さらに４．２Ｖの定電圧で電流値が４６ｍＡになるまで定電圧充電させた後、４６０ｍＡの定電流で２．７５Ｖになるまで放電させて、各非水電解液二次電池の初期放電容量を測定した。そして、比較例１の非水電解液二次電池における初期放電容量を１００として、各非水電解液二次電池の初期放電容量を算出し、その結果を下記の表１に示した。なお、表１においては、４−フルオロエチレンカーボネートを４−ＦＥＣ、ジメチルカーボネートＤＭＣ、エチレンカーボネートをＥＣ、エチルメチルカーボネートをＥＭＣ、ビニレンカーボネートをＶＣとして示した。 And each nonaqueous electrolyte secondary battery of Examples 1-6 produced as mentioned above and Comparative Examples 1-7 was charged until it became 4.2V with a constant current of 460 mA at 25 ° C, respectively. After charging at a constant voltage of 4.2 V until the current value reaches 46 mA, the battery is discharged at a constant current of 460 mA until it reaches 2.75 V, and the initial discharge capacity of each non-aqueous electrolyte secondary battery is measured. did. Then, assuming that the initial discharge capacity in the nonaqueous electrolyte secondary battery of Comparative Example 1 was 100, the initial discharge capacity of each nonaqueous electrolyte secondary battery was calculated, and the results are shown in Table 1 below. In Table 1, 4-fluoroethylene carbonate is shown as 4-FEC, dimethyl carbonate DMC, ethylene carbonate as EC, ethyl methyl carbonate as EMC, and vinylene carbonate as VC.
この結果、非水系溶媒として、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＦ3ＣＨ2ＣＯＯＣＨ3やＣＨ3ＣＯＯＣＨ2ＣＦ3と、金属リチウムとリチウムイオンとの平衡電位を基準として分解される電位が＋１．０〜３．０Ｖの範囲から外れたエチレンカーボネートとの混合溶媒を用いた比較例６，７の各非水電解液二次電池は、実施例１〜６及び比較例１〜５の各非水電解液二次電池に比べて、初期放電容量が大きく低下していた。 As a result, as a non-aqueous solvent, CF 3 CH 2 COOCH 3 or CH 3 COOCH 2 CF 3 which is a fluorinated chain carboxylic acid ester represented by the above formula (1), and an equilibrium potential between lithium metal and lithium ion The nonaqueous electrolyte secondary batteries of Comparative Examples 6 and 7 using a mixed solvent with ethylene carbonate whose potential decomposed on the basis of +1.0 to 3.0 V is out of the range of +1.0 to 3.0 V are shown in Examples 1 to 6. And compared with each non-aqueous-electrolyte secondary battery of Comparative Examples 1-5, the initial stage discharge capacity was falling significantly.
次に、上記の実施例１〜６及び比較例１〜７の各非水電解液二次電池について、それぞれ２５℃において、４６０ｍＡの定電流で４．２Ｖになるまで充電し、さらに４．２Ｖの定電圧で電流値が４６ｍＡになるまで定電圧充電させた後、４６０ｍＡの定電流で２．７５Ｖになるまで放電させて保存前の放電容量Ｄ1を測定した。 Next, for each of the nonaqueous electrolyte secondary batteries of Examples 1 to 6 and Comparative Examples 1 to 7, the batteries were charged at 25 ° C. to 4.2 V at a constant current of 460 mA, and further 4.2 V. The battery was charged at a constant voltage until the current value reached 46 mA at a constant voltage of 1, and then discharged at a constant current of 460 mA until it reached 2.75 V, and the discharge capacity D 1 before storage was measured.
次いで、上記の各非水電解液二次電池を、それぞれ２５℃において、２３００ｍＡの定電流で４．２Ｖになるまで充電し、さらに４．２Ｖの定電圧で電流値が４６ｍＡになるまで定電圧充電させ、この状態で各非水電解液二次電池を恒温槽内において６０℃で１０日間保存した後、保存後の各非水電解液二次電池について、それぞれ２５℃において、４６０ｍＡの定電流で２．７５Ｖになるまで放電させて保存後の残存容量Ｄ2を求めた。 Next, each non-aqueous electrolyte secondary battery is charged at 25 ° C. with a constant current of 2300 mA until it reaches 4.2 V, and further with a constant voltage of 4.2 V, a constant voltage until the current value reaches 46 mA. In this state, each non-aqueous electrolyte secondary battery was stored in a thermostatic bath at 60 ° C. for 10 days, and then each non-aqueous electrolyte secondary battery after storage was 460 mA constant current at 25 ° C. The battery was discharged until 2.75 V, and the remaining capacity D 2 after storage was determined.
その後、上記の各非水電解液二次電池を、それぞれ２５℃において、４６０ｍＡの定電流で４．２Ｖになるまで充電し、さらに４．２Ｖの定電圧で電流値が４６ｍＡになるまで定電圧充電させた後、４６０ｍＡの定電流で２．７５Ｖになるまで放電させて保存後の復帰容量Ｄ3を測定した。 Thereafter, each non-aqueous electrolyte secondary battery is charged at 25 ° C. with a constant current of 460 mA until it reaches 4.2 V, and further with a constant voltage of 4.2 V, a constant voltage until the current value reaches 46 mA. After charging, the battery was discharged at a constant current of 460 mA until it reached 2.75 V, and the return capacity D 3 after storage was measured.
そして、上記のように測定した保存前の放電容量Ｄ1、保存後の残存容量Ｄ2及び保存後の復帰容量Ｄ3に基づき、下記の式により実施例１〜６及び比較例１〜７の各非水電解液二次電池の保存後における容量残存率（％）及び容量復帰率（％）を求め、その結果を下記の表２に示した。 Then, based on the discharge capacity D 1 before storage, the remaining capacity D 2 after storage, and the return capacity D 3 after storage measured as described above, the following expressions are used for Examples 1-6 and Comparative Examples 1-7. The capacity remaining rate (%) and the capacity recovery rate (%) after storage of each non-aqueous electrolyte secondary battery were determined, and the results are shown in Table 2 below.
容量残存率（％）＝（Ｄ2／Ｄ1）×１００
容量復帰率（％）＝（Ｄ3／Ｄ1）×１００
Capacity remaining rate (%) = (D 2 / D 1 ) × 100
Capacity recovery rate (%) = (D 3 / D 1 ) × 100
この結果、非水系溶媒として、金属リチウムとリチウムイオンとの平衡電位を基準とした分解電位が＋１．０〜３．０Ｖの範囲にある被膜形成化合物の４−フルオロエチレンカーボネートと、上記の式（１）に示したフッ素化鎖状カルボン酸エステルとの混合溶媒を用いた実施例１〜６の各非水電解液二次電池は、フッ素化を行っていない鎖状カルボン酸エステルを用いた比較例２，３の非水電解液二次電池や、金属リチウムとリチウムイオンとの平衡電位を基準として分解される電位が＋１．０〜３．０Ｖの範囲から外れたエチレンカーボネートを用いた比較例６，７の非水電解液二次電池や、従来より一般に用いられているエチレンカーボネートとエチルメチルカーボネートとの混合溶媒にビニレンカーボネートを添加させたものを用いた比較例１の非水電解液二次電池に比べて、保存後の容量残存率が明らかに向上していると共に、保存後の容量復帰率も向上していた。
As a result, as a non-aqueous solvent, 4-fluoroethylene carbonate, which is a film-forming compound having a decomposition potential in the range of +1.0 to 3.0 V based on the equilibrium potential of metallic lithium and lithium ions, and the above formula ( Each nonaqueous electrolyte secondary battery of Examples 1 to 6 using a mixed solvent with the fluorinated chain carboxylic acid ester shown in 1) is a comparison using a chain carboxylic acid ester that has not been fluorinated. Comparative examples using the non-aqueous electrolyte secondary batteries of Examples 2 and 3 and ethylene carbonate whose potential decomposed on the basis of the equilibrium potential of metallic lithium and lithium ions deviated from the range of +1.0 to 3.0
また、α炭素における水素がフッ素で置換されたフッ素化鎖状カルボン酸エステルであるＣＨＦ2ＣＯＯＣＨ2ＣＨ3やＣＨＦ2ＣＯＯＣＨ3を用いた比較例４，５の非水電解液二次電池においては、保存後の容量残存率及び容量復帰率が大きく低下していた。これは、α炭素に電子吸引性の高いフッ素が結合することで、隣接するカルボニル炭素の電子密度が低下して、非水電解液が負極と反応したためであると考えられる。 In the non-aqueous electrolyte secondary batteries of Comparative Examples 4 and 5 using CHF 2 COOCH 2 CH 3 or CHF 2 COOCH 3 which are fluorinated chain carboxylic acid esters in which hydrogen at the α-carbon is substituted with fluorine, The capacity remaining rate and the capacity recovery rate after storage were greatly reduced. This is thought to be because non-aqueous electrolyte reacted with the negative electrode because the electron density of the adjacent carbonyl carbon decreased due to the binding of fluorine with high electron-withdrawing property to α-carbon.
（実施例７）
実施例７においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、プロピレンカーボネート（ＰＣ）と、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＦ3ＣＨ2ＣＯＯＣＨ3とを２０：５：７５の体積比で混合させた混合溶媒を用い、この混合溶媒に電解質としてヘキサフルオロリン酸リチウムＬｉＰＦ6を１．１ｍｏｌ／ｌの割合で溶解させ、それ以外は、上記の実施例１の場合と同様にして、図１に示すような円筒型で、充電終止電圧が４．３Ｖ、設計容量が２７００ｍＡｈの非水電解液二次電池を作製した。
(Example 7)
In Example 7, in the preparation of the non-aqueous electrolyte in Example 1 above, as the non-aqueous solvent, 4-fluoroethylene carbonate (4-FEC), which is the same film forming compound as in Example 1, and propylene carbonate (PC ) And CF 3 CH 2 COOCH 3 , which is a fluorinated chain carboxylic acid ester represented by the above formula (1), at a volume ratio of 20: 5: 75. Lithium hexafluorophosphate LiPF 6 as an electrolyte was dissolved at a rate of 1.1 mol / l, and other than that, in the same manner as in Example 1 above, a cylindrical shape as shown in FIG. Produced a non-aqueous electrolyte secondary battery having a design capacity of 4.3 V and a design capacity of 2700 mAh.
（実施例８）
実施例８においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、プロピレンカーボネート（ＰＣ）と、上記の式（１）に示したフッ素化鎖状カルボン酸エステルであるＣＨ3ＣＯＯＣＨ2ＣＦ3とを２０：５：７５の体積比で混合させた混合溶媒を用い、この混合溶媒に電解質としてヘキサフルオロリン酸リチウムＬｉＰＦ6を１．１ｍｏｌ／ｌの割合で溶解させ、それ以外は、上記の実施例１の場合と同様にして、実施例７の場合と同様の円筒型で、充電終止電圧が４．３Ｖ、設計容量が２７００ｍＡｈの非水電解液二次電池を作製した。
(Example 8)
In Example 8, in the preparation of the non-aqueous electrolyte in Example 1 above, as the non-aqueous solvent, 4-fluoroethylene carbonate (4-FEC) and propylene carbonate (PC) which are the same film-forming compounds as Example 1 were used. ) And CH 3 COOCH 2 CF 3 , which is a fluorinated chain carboxylic acid ester represented by the above formula (1), at a volume ratio of 20: 5: 75. Lithium hexafluorophosphate LiPF 6 as an electrolyte was dissolved at a rate of 1.1 mol / l, and other than that, the same cylindrical shape as in Example 7 was charged in the same manner as in Example 1 above. A non-aqueous electrolyte secondary battery with a final voltage of 4.3 V and a design capacity of 2700 mAh was produced.
（比較例８）
比較例８においては、上記の実施例１における非水電解液の作製において、非水系溶媒として、実施例１と同じ被膜形成化合物の４−フルオロエチレンカーボネート（４−ＦＥＣ）と、プロピレンカーボネート（ＰＣ）と、エチルメチルカーボネート（ＥＭＣ）とを２０：５：７５の体積比で混合させた混合溶媒を用い、この混合溶媒に電解質としてヘキサフルオロリン酸リチウムＬｉＰＦ6を１．１ｍｏｌ／ｌの割合で溶解させ、それ以外は、上記の実施例１の場合と同様にして、実施例７，８の場合と同様の円筒型で、充電終止電圧が４．３Ｖ、設計容量が２７００ｍＡｈの非水電解液二次電池を作製した。
(Comparative Example 8)
In Comparative Example 8, in the preparation of the non-aqueous electrolyte in Example 1 above, 4-fluoroethylene carbonate (4-FEC), which is the same film forming compound as Example 1, and propylene carbonate (PC) were used as the non-aqueous solvent. ) And ethyl methyl carbonate (EMC) in a volume ratio of 20: 5: 75, and lithium hexafluorophosphate LiPF 6 was added to the mixed solvent as an electrolyte at a rate of 1.1 mol / l. Otherwise, in the same manner as in Example 1 above, the same non-aqueous electrolyte as in Examples 7 and 8, with a cylindrical charge termination voltage of 4.3 V and a design capacity of 2700 mAh A secondary battery was produced.
そして、上記のように作製した実施例７，８及び比較例８の各非水電解液二次電池を、それぞれ２５℃において、１０００ｍＡの定電流で４．３Ｖになるまで充電し、さらに４．３Ｖの定電圧で電流値が５４ｍＡになるまで定電圧充電させた後、５４０ｍＡの定電流で３．０Ｖになるまで放電させて、各非水電解液二次電池の初期放電容量を測定した。そして、比較例８の非水電解液二次電池における初期放電容量を１００として、各非水電解液二次電池の初期放電容量を算出し、その結果を下記の表３に示した。 Then, the nonaqueous electrolyte secondary batteries of Examples 7 and 8 and Comparative Example 8 manufactured as described above were charged at a constant current of 1000 mA at a constant current of 1000 mA to 25 V, respectively. After charging at a constant voltage of 3 V until the current value reached 54 mA, the battery was discharged at a constant current of 540 mA until it reached 3.0 V, and the initial discharge capacity of each non-aqueous electrolyte secondary battery was measured. Then, assuming that the initial discharge capacity in the nonaqueous electrolyte secondary battery of Comparative Example 8 was 100, the initial discharge capacity of each nonaqueous electrolyte secondary battery was calculated, and the results are shown in Table 3 below.
この結果、実施例７，８及び比較例８の各非水電解液二次電池においては、略同じ初期放電容量が得られた。 As a result, in the nonaqueous electrolyte secondary batteries of Examples 7 and 8 and Comparative Example 8, substantially the same initial discharge capacity was obtained.
次に、上記の実施例７，８及び比較例８の各非水電解液二次電池について、それぞれ２５℃において、１０００ｍＡの定電流で４．３Ｖになるまで充電し、さらに４．３Ｖの定電圧で電流値が５４ｍＡになるまで定電圧充電させた後、２７００ｍＡの定電流で３．０Ｖになるまで放電させて保存前の放電容量Ｄ1を測定した。 Next, each of the nonaqueous electrolyte secondary batteries of Examples 7 and 8 and Comparative Example 8 was charged at 25 ° C. to a voltage of 4.3 V at a constant current of 1000 mA, and further adjusted to a constant voltage of 4.3 V. The battery was charged at a constant voltage until the current value became 54 mA, and then discharged at a constant current of 2700 mA until 3.0 V, and the discharge capacity D 1 before storage was measured.
次いで、上記の各非水電解液二次電池を、それぞれ２５℃において、１０００ｍＡの定電流で４．３Ｖになるまで充電し、さらに４．３Ｖの定電圧で電流値が５４ｍＡになるまで定電圧充電させ、この状態で各非水電解液二次電池を恒温槽内において６０℃で２０日間保存した。 Next, each of the above non-aqueous electrolyte secondary batteries is charged at 25 ° C. with a constant current of 1000 mA until reaching 4.3 V, and further with a constant voltage of 4.3 V until a current value becomes 54 mA. In this state, each non-aqueous electrolyte secondary battery was stored in a thermostat at 60 ° C. for 20 days.
そして、保存前と保存後とにおける各非水電解液二次電池の電池電圧を測定し、電圧変化の結果を下記の表４に示した。 The battery voltage of each non-aqueous electrolyte secondary battery before and after storage was measured, and the results of voltage change are shown in Table 4 below.
また、保存後の各非水電解液二次電池について、それぞれ２５℃において、２７００ｍＡの定電流で３．０Ｖになるまで放電させて保存後の残存容量Ｄ2を求めた。 Each non-aqueous electrolyte secondary battery after storage was discharged at 25 ° C. at a constant current of 2700 mA until it reached 3.0 V, and the remaining capacity D 2 after storage was determined.
その後、上記の各非水電解液二次電池を、それぞれ２５℃において、１０００ｍＡの定電流で４．３Ｖになるまで充電し、さらに４．３Ｖの定電圧で電流値が５４ｍＡになるまで定電圧充電させた後、２７００ｍＡの定電流で３．０Ｖになるまで放電させて保存後の復帰容量Ｄ3を測定した。 Thereafter, each of the above non-aqueous electrolyte secondary batteries is charged at 25 ° C. with a constant current of 1000 mA until reaching 4.3 V, and further at a constant voltage of 4.3 V until the current value becomes 54 mA. After charging, the battery was discharged at a constant current of 2700 mA until 3.0 V, and the return capacity D 3 after storage was measured.
そして、上記のように測定した保存前の放電容量Ｄ1、保存後の残存容量Ｄ2及び保存後の復帰容量Ｄ3に基づき、実施例１〜６及び比較例１〜７の各非水電解液二次電池の場合と同じ前記の式により、保存後における容量残存率（％）及び容量復帰率（％）を求め、その結果を下記の表４に示した。 Then, based on the discharge capacity D 1, the remaining capacity D 2 and after storage after storage resetting capacity D 3 before storage was measured as described above, each of the non-aqueous electrolyte in Examples 1 to 6 and Comparative Examples 1 to 7 The capacity remaining rate (%) and the capacity recovery rate (%) after storage were obtained by the same formula as in the case of the liquid secondary battery, and the results are shown in Table 4 below.
この結果、非水系溶媒として、金属リチウムとリチウムイオンとの平衡電位を基準とした分解電位が＋１．０〜３．０Ｖの範囲にある被膜形成化合物の４−フルオロエチレンカーボネートと、上記の式（１）に示したフッ素化鎖状カルボン酸エステルとを含む混合溶媒を用いた実施例７，８の各非水電解液二次電池は、上記の式（１）に示したフッ素化鎖状カルボン酸エステルに代えてエチルメチルカーボネート（ＥＭＣ）を用いた比較例８の非水電解液二次電池に比べ、保存後の電池電圧及び容量残存率が向上していた。 As a result, as a non-aqueous solvent, 4-fluoroethylene carbonate, which is a film-forming compound having a decomposition potential in the range of +1.0 to 3.0 V based on the equilibrium potential of metallic lithium and lithium ions, and the above formula ( Each of the nonaqueous electrolyte secondary batteries of Examples 7 and 8 using a mixed solvent containing the fluorinated chain carboxylic acid ester shown in 1) is a fluorinated chain carboxylic acid shown in the above formula (1). Compared with the nonaqueous electrolyte secondary battery of Comparative Example 8 using ethyl methyl carbonate (EMC) instead of acid ester, the battery voltage and capacity remaining rate after storage were improved.
特に、上記の式（１）に示したフッ素化鎖状カルボン酸エステルとして、３，３，３−トリフルオロプロピオン酸メチルＣＦ3ＣＨ2ＣＯＯＣＨ3を用いた実施例７の非水電解液二次電池においては、保存後の容量残存率及び容量復帰率がさらに向上していた。 In particular, the non-aqueous electrolyte secondary of Example 7 using methyl 3,3,3-trifluoropropionate CF 3 CH 2 COOCH 3 as the fluorinated chain carboxylic acid ester represented by the above formula (1) In the battery, the capacity remaining rate and the capacity recovery rate after storage were further improved.
１ 正極
２ 負極
３ セパレータ
４ 電池缶
５ 正極タブ
６ 正極蓋
７ 負極タブ
８ 絶縁パッキン
９ 正極外部端子
DESCRIPTION OF
Claims (12)
Ｒ１−ＣＨ2−ＣＯＯ−Ｒ２ （１）
（式中、Ｒ１は水素又はアルキル基、Ｒ２はアルキル基を表し、Ｒ１とＲ２とにおける炭素数の和が３以内であり、Ｒ１が水素である場合には、Ｒ２における水素の少なくとも一部がフッ素で置換され、Ｒ１がアルキル基である場合には、Ｒ１及び／又はＲ２における水素の少なくとも一部がフッ素で置換されている。） An electrolyte lithium salt is contained in the non-aqueous solvent, and the above non-aqueous solvent contains +1 based on the equilibrium potential of the fluorinated chain carboxylate ester represented by the following formula (1), metal lithium and lithium ion: A film-forming compound that is decomposed in a range of 0.0 to 3.0 V, and the fluorinated chain carboxylic acid ester is contained in a range of 20 to 80% by volume with respect to the whole non-aqueous solvent. Nonaqueous electrolyte for secondary batteries.
R1-CH 2 -COO-R2 ( 1)
(Wherein R1 represents hydrogen or an alkyl group, R2 represents an alkyl group, the sum of the carbon numbers in R1 and R2 is 3 or less, and when R1 is hydrogen, at least a part of the hydrogen in R2 is When substituted with fluorine and R1 is an alkyl group, at least a part of hydrogen in R1 and / or R2 is substituted with fluorine.)
Ｒ１−ＣＨ 2 −ＣＯＯ−Ｒ２ （１）
（式中、Ｒ１は水素又はアルキル基、Ｒ２はアルキル基を表し、Ｒ１とＲ２とにおける炭素数の和が３以内であり、Ｒ１が水素である場合には、Ｒ２における水素の少なくとも一部がフッ素で置換され、Ｒ１がアルキル基である場合には、Ｒ１及び／又はＲ２における水素の少なくとも一部がフッ素で置換されている。） An electrolyte lithium salt is contained in the non-aqueous solvent, and the above non-aqueous solvent contains +1 based on the equilibrium potential of the fluorinated chain carboxylate ester represented by the following formula (1), metal lithium and lithium ion: A film-forming compound that is decomposed in the range of 0.0 to 3.0 V, and the film-forming compound is 4-fluoroethylene carbonate, ethylene sulfite, vinyl ethylene carbonate, LiB (C 2 O 4 ) 2 , LiBF 2 A non-aqueous electrolyte for a secondary battery, which is at least one selected from (C 2 O 4 ).
R1-CH 2 -COO-R2 ( 1)
(Wherein R1 represents hydrogen or an alkyl group, R2 represents an alkyl group, the sum of the carbon numbers in R1 and R2 is 3 or less, and when R1 is hydrogen, at least a part of the hydrogen in R2 is When substituted with fluorine and R1 is an alkyl group, at least a part of hydrogen in R1 and / or R2 is substituted with fluorine.)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008024651A JP5235437B2 (en) | 2007-02-20 | 2008-02-05 | Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007038791 | 2007-02-20 | ||
| JP2007038791 | 2007-02-20 | ||
| JP2008525325 | 2007-11-28 | ||
| JP2008525325 | 2007-11-28 | ||
| JP2008024651A JP5235437B2 (en) | 2007-02-20 | 2008-02-05 | Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| JP2009289414A JP2009289414A (en) | 2009-12-10 |
| JP2009289414A5 JP2009289414A5 (en) | 2011-01-20 |
| JP5235437B2 true JP5235437B2 (en) | 2013-07-10 |
Family
ID=41458457
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008024651A Active JP5235437B2 (en) | 2007-02-20 | 2008-02-05 | Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5235437B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9673450B2 (en) | 2011-09-02 | 2017-06-06 | Solvay Sa | Lithium ion battery |
| US9979050B2 (en) | 2011-09-02 | 2018-05-22 | Solvay Sa | Fluorinated electrolyte compositions |
| US10044066B2 (en) | 2012-06-01 | 2018-08-07 | Solvary SA | Fluorinated electrolyte compositions |
| US10074874B2 (en) | 2012-06-01 | 2018-09-11 | Solvay Sa | Additives to improve electrolyte performance in lithium ion batteries |
| US10686220B2 (en) | 2013-04-04 | 2020-06-16 | Solvay Sa | Nonaqueous electrolyte compositions |
| US10903523B2 (en) | 2016-09-30 | 2021-01-26 | Panasonic Corporation | Nonaqueous electrolyte and nonaqueous electrolyte secondary battery |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5323837B2 (en) * | 2007-09-12 | 2013-10-23 | エルジー・ケム・リミテッド | Non-aqueous electrolyte lithium secondary battery |
| JP5593982B2 (en) * | 2010-09-03 | 2014-09-24 | 日産自動車株式会社 | Non-aqueous electrolyte composition and non-aqueous electrolyte secondary battery |
| EP2652832A1 (en) * | 2010-12-15 | 2013-10-23 | Dow Global Technologies LLC | Battery electrolyte solution containing certain ester-based solvents, and batteries containing such an electrolyte solution |
| CN103688402B (en) * | 2011-07-14 | 2016-05-11 | 株式会社Lg化学 | Non-aqueous electrolytic solution and the lithium secondary battery that uses it |
| WO2013088622A1 (en) * | 2011-12-14 | 2013-06-20 | パナソニック株式会社 | Lithium-ion secondary battery |
| WO2015004841A1 (en) | 2013-07-08 | 2015-01-15 | パナソニックＩｐマネジメント株式会社 | Nonaqueous electrolyte secondary battery |
| JP2017001953A (en) * | 2013-11-07 | 2017-01-05 | 関東電化工業株式会社 | Ester having 3,3,3-trifluoropropionate group and manufacturing method therefor |
| JP6517069B2 (en) * | 2014-06-30 | 2019-05-22 | パナソニック株式会社 | Non-aqueous electrolyte secondary battery |
| US20170317380A1 (en) * | 2014-12-26 | 2017-11-02 | Sanyo Electric Co., Ltd. | Nonaqueous electrolyte secondary battery |
| JPWO2016151983A1 (en) * | 2015-03-26 | 2018-01-18 | 三洋電機株式会社 | Nonaqueous electrolyte secondary battery |
| JP6628697B2 (en) * | 2015-09-30 | 2020-01-15 | パナソニック株式会社 | Non-aqueous electrolyte secondary battery |
| JP6656623B2 (en) * | 2016-05-17 | 2020-03-04 | 株式会社Ｇｓユアサ | Non-aqueous electrolyte for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery, and method for producing non-aqueous electrolyte secondary battery |
| JP6700166B2 (en) * | 2016-12-26 | 2020-05-27 | トヨタ自動車株式会社 | Non-aqueous electrolyte solution, non-aqueous electrolyte secondary battery, and method for manufacturing non-aqueous electrolyte secondary battery |
| CN109997271B (en) | 2016-12-26 | 2022-09-02 | 松下知识产权经营株式会社 | Nonaqueous electrolyte secondary battery |
| JP6779775B2 (en) | 2016-12-26 | 2020-11-04 | ダイキン工業株式会社 | Electrolyte, electrochemical device, lithium-ion secondary battery, and module |
| EP3522288A4 (en) | 2016-12-26 | 2020-08-26 | Daikin Industries, Ltd. | Electrolytic solution, electrochemical device, lithium-ion secondary cell, and module |
| CN110383563B (en) * | 2017-03-29 | 2022-09-16 | 松下知识产权经营株式会社 | Nonaqueous electrolyte and nonaqueous electrolyte secondary battery |
| WO2018179885A1 (en) | 2017-03-31 | 2018-10-04 | パナソニックＩｐマネジメント株式会社 | Secondary battery |
| US20220045364A1 (en) | 2019-03-11 | 2022-02-10 | Panasonic Intellectual Property Management Co., Ltd. | Non-aqueous electrolyte secondary battery |
| CN114520371B (en) * | 2022-02-18 | 2024-04-05 | 香河昆仑新能源材料股份有限公司 | Nonaqueous electrolyte and lithium ion battery comprising same |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3311611B2 (en) * | 1996-10-11 | 2002-08-05 | 三洋電機株式会社 | Lithium secondary battery |
| JP2002124263A (en) * | 2000-10-12 | 2002-04-26 | Daikin Ind Ltd | Coating film forming material for electrode surface and manufacturing method for battery |
| JP2003282138A (en) * | 2002-03-26 | 2003-10-03 | Mitsubishi Chemicals Corp | Nonaqueous electrolyte secondary battery and electrolyte used in it |
| JP2004281185A (en) * | 2003-03-14 | 2004-10-07 | Sanyo Electric Co Ltd | Nonaqueous electrolytic solution for battery, and nonaqueous electrolytic solution battery |
| JP2006210022A (en) * | 2005-01-25 | 2006-08-10 | Toyota Motor Corp | Electrolyte and its utilization |
| JP2009176786A (en) * | 2008-01-22 | 2009-08-06 | Hitachi Chem Co Ltd | Hybrid capacitor |
-
2008
- 2008-02-05 JP JP2008024651A patent/JP5235437B2/en active Active
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9673450B2 (en) | 2011-09-02 | 2017-06-06 | Solvay Sa | Lithium ion battery |
| US9979050B2 (en) | 2011-09-02 | 2018-05-22 | Solvay Sa | Fluorinated electrolyte compositions |
| US10044066B2 (en) | 2012-06-01 | 2018-08-07 | Solvary SA | Fluorinated electrolyte compositions |
| US10074874B2 (en) | 2012-06-01 | 2018-09-11 | Solvay Sa | Additives to improve electrolyte performance in lithium ion batteries |
| US10686220B2 (en) | 2013-04-04 | 2020-06-16 | Solvay Sa | Nonaqueous electrolyte compositions |
| US10916805B2 (en) | 2013-04-04 | 2021-02-09 | Solvay Sa | Nonaqueous electrolyte compositions |
| US10903523B2 (en) | 2016-09-30 | 2021-01-26 | Panasonic Corporation | Nonaqueous electrolyte and nonaqueous electrolyte secondary battery |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2009289414A (en) | 2009-12-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5235437B2 (en) | Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery | |
| JP5461883B2 (en) | Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery | |
| US8945781B2 (en) | Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery | |
| JP5374339B2 (en) | ELECTROLYTE SOLUTION FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY CONTAINING THE SAME | |
| JP5494472B2 (en) | Nonaqueous electrolyte for lithium battery and lithium battery using the same | |
| JP5350243B2 (en) | Non-aqueous electrolyte and secondary battery using the same | |
| JP3475911B2 (en) | Non-aqueous electrolyte and lithium secondary battery using the same | |
| US20020192565A1 (en) | Non-aqueous electrolyte secondary battery | |
| JP6068789B2 (en) | ELECTROLYTE SOLUTION FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY CONTAINING THE SAME | |
| JP5474785B2 (en) | Non-aqueous electrolyte and secondary battery equipped with the same | |
| JP2011192632A (en) | Electrolytic solution for lithium secondary battery, and lithium secondary battery | |
| JP2009140919A (en) | Nonaqueous secondary battery | |
| KR20190109099A (en) | Electrolyte for rechargeable lithium battery and rechargeable lithium battery | |
| JP2007087883A (en) | Nonaqueous electrolyte for secondary battery and nonaqueous electrolyte secondary battery | |
| JP2009231261A (en) | Nonaqueous electrolyte secondary battery | |
| KR101683211B1 (en) | Electrolyte for rechargeable lithium battery, and rechargeable lithium battery including the same | |
| EP4002538A1 (en) | Electrolyte additive for lithium secondary battery, and electrolyte for lithium secondary battery and lithium secondary battery, which comprise same | |
| JPH08298134A (en) | Nonaqueous electrolyte | |
| JP2002367674A (en) | Electrolyte and secondary battery | |
| JP2007220337A (en) | Nonaqueous electrolytic solution for secondary battery and nonaqueous electrolyte secondary battery | |
| JPWO2018123213A1 (en) | Nonaqueous electrolyte secondary battery | |
| JP2022510186A (en) | Electrolyte composition and secondary battery using it | |
| JP5398321B2 (en) | Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery | |
| WO2018016767A1 (en) | Lithium secondary battery electrolyte and lithium secondary battery comprising same | |
| KR20210041382A (en) | Electrolyte for rechargeable lithium battery and rechargeable lithium battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080208 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20101125 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20101125 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20130108 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20130219 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20130312 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20130326 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 Ref document number: 5235437 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20160405 Year of fee payment: 3 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313115 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |