WO2016083271A1 - Lithium electrodes for lithium-sulphur batteries - Google Patents
Lithium electrodes for lithium-sulphur batteries Download PDFInfo
- Publication number
- WO2016083271A1 WO2016083271A1 PCT/EP2015/077288 EP2015077288W WO2016083271A1 WO 2016083271 A1 WO2016083271 A1 WO 2016083271A1 EP 2015077288 W EP2015077288 W EP 2015077288W WO 2016083271 A1 WO2016083271 A1 WO 2016083271A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- film
- current collector
- composition
- lithium
- medium
- Prior art date
Links
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 62
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 58
- JDZCKJOXGCMJGS-UHFFFAOYSA-N [Li].[S] Chemical compound [Li].[S] JDZCKJOXGCMJGS-UHFFFAOYSA-N 0.000 title claims abstract description 10
- 229910052751 metal Inorganic materials 0.000 claims abstract description 72
- 239000002184 metal Substances 0.000 claims abstract description 72
- 238000000034 method Methods 0.000 claims abstract description 70
- 230000008569 process Effects 0.000 claims abstract description 55
- 239000000178 monomer Substances 0.000 claims abstract description 52
- 229920000642 polymer Polymers 0.000 claims abstract description 48
- 239000000203 mixture Substances 0.000 claims abstract description 38
- 238000004519 manufacturing process Methods 0.000 claims abstract description 34
- 238000001035 drying Methods 0.000 claims abstract description 19
- 125000000524 functional group Chemical group 0.000 claims abstract description 18
- 229920002313 fluoropolymer Polymers 0.000 claims abstract description 16
- 239000004811 fluoropolymer Substances 0.000 claims abstract description 16
- 125000005910 alkyl carbonate group Chemical group 0.000 claims abstract description 13
- 239000007788 liquid Substances 0.000 claims abstract description 7
- 238000012545 processing Methods 0.000 claims abstract description 7
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 17
- 239000005864 Sulphur Substances 0.000 claims description 17
- -1 cyclic alkylene carbonates Chemical class 0.000 claims description 17
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 13
- 229910052799 carbon Inorganic materials 0.000 claims description 8
- 125000000217 alkyl group Chemical group 0.000 claims description 7
- 238000000151 deposition Methods 0.000 claims description 7
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 7
- 229910006145 SO3Li Inorganic materials 0.000 claims description 4
- 125000004169 (C1-C6) alkyl group Chemical group 0.000 claims description 3
- 150000005215 alkyl ethers Chemical class 0.000 claims description 3
- 229910052701 rubidium Inorganic materials 0.000 claims description 3
- 239000010410 layer Substances 0.000 description 65
- 210000004027 cell Anatomy 0.000 description 39
- ZUHZGEOKBKGPSW-UHFFFAOYSA-N tetraglyme Chemical compound COCCOCCOCCOCCOC ZUHZGEOKBKGPSW-UHFFFAOYSA-N 0.000 description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 18
- 230000000052 comparative effect Effects 0.000 description 17
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
- 229920001021 polysulfide Polymers 0.000 description 15
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 12
- WNXJIVFYUVYPPR-UHFFFAOYSA-N 1,3-dioxolane Chemical compound C1COCO1 WNXJIVFYUVYPPR-UHFFFAOYSA-N 0.000 description 9
- 239000003792 electrolyte Substances 0.000 description 9
- 239000011888 foil Substances 0.000 description 9
- QSZMZKBZAYQGRS-UHFFFAOYSA-N lithium;bis(trifluoromethylsulfonyl)azanide Chemical compound [Li+].FC(F)(F)S(=O)(=O)[N-]S(=O)(=O)C(F)(F)F QSZMZKBZAYQGRS-UHFFFAOYSA-N 0.000 description 9
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 description 9
- 229910003473 lithium bis(trifluoromethanesulfonyl)imide Inorganic materials 0.000 description 8
- 239000004743 Polypropylene Substances 0.000 description 7
- 230000007246 mechanism Effects 0.000 description 7
- 229920001155 polypropylene Polymers 0.000 description 7
- 239000000843 powder Substances 0.000 description 7
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 229910006095 SO2F Inorganic materials 0.000 description 6
- 239000002253 acid Substances 0.000 description 6
- 229910001416 lithium ion Inorganic materials 0.000 description 6
- 230000014759 maintenance of location Effects 0.000 description 6
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 5
- 230000008021 deposition Effects 0.000 description 5
- 238000002848 electrochemical method Methods 0.000 description 5
- 239000010935 stainless steel Substances 0.000 description 5
- 229910001220 stainless steel Inorganic materials 0.000 description 5
- 125000002733 (C1-C6) fluoroalkyl group Chemical group 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 229920000557 Nafion® Polymers 0.000 description 4
- 229910006069 SO3H Inorganic materials 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 229910052731 fluorine Inorganic materials 0.000 description 4
- 238000003475 lamination Methods 0.000 description 4
- 239000002243 precursor Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 238000007738 vacuum evaporation Methods 0.000 description 4
- 229910007552 Li2Sn Inorganic materials 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- 239000004411 aluminium Substances 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000004320 controlled atmosphere Methods 0.000 description 3
- 125000004122 cyclic group Chemical group 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 125000001033 ether group Chemical group 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 125000001153 fluoro group Chemical group F* 0.000 description 3
- 239000004816 latex Substances 0.000 description 3
- 229920000126 latex Polymers 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 238000006116 polymerization reaction Methods 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 229910052700 potassium Inorganic materials 0.000 description 3
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 229910052708 sodium Inorganic materials 0.000 description 3
- AYCANDRGVPTASA-UHFFFAOYSA-N 1-bromo-1,2,2-trifluoroethene Chemical group FC(F)=C(F)Br AYCANDRGVPTASA-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 description 2
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 229910052792 caesium Inorganic materials 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- UUAGAQFQZIEFAH-UHFFFAOYSA-N chlorotrifluoroethylene Chemical group FC(F)=C(F)Cl UUAGAQFQZIEFAH-UHFFFAOYSA-N 0.000 description 2
- 229960001760 dimethyl sulfoxide Drugs 0.000 description 2
- 238000003618 dip coating Methods 0.000 description 2
- 150000002170 ethers Chemical class 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 239000006262 metallic foam Substances 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000005191 phase separation Methods 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000004528 spin coating Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 238000010345 tape casting Methods 0.000 description 2
- MHNPWFZIRJMRKC-UHFFFAOYSA-N 1,1,2-trifluoroethene Chemical compound F[C]=C(F)F MHNPWFZIRJMRKC-UHFFFAOYSA-N 0.000 description 1
- QMIWYOZFFSLIAK-UHFFFAOYSA-N 3,3,3-trifluoro-2-(trifluoromethyl)prop-1-ene Chemical group FC(F)(F)C(=C)C(F)(F)F QMIWYOZFFSLIAK-UHFFFAOYSA-N 0.000 description 1
- 229910017048 AsF6 Inorganic materials 0.000 description 1
- 239000002000 Electrolyte additive Substances 0.000 description 1
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 1
- 229910005143 FSO2 Inorganic materials 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- 229910015040 LiAsFe Inorganic materials 0.000 description 1
- 229910013188 LiBOB Inorganic materials 0.000 description 1
- 229910001290 LiPF6 Inorganic materials 0.000 description 1
- 229910000792 Monel Inorganic materials 0.000 description 1
- SUAKHGWARZSWIH-UHFFFAOYSA-N N,N‐diethylformamide Chemical compound CCN(CC)C=O SUAKHGWARZSWIH-UHFFFAOYSA-N 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004159 Potassium persulphate Substances 0.000 description 1
- 229910006080 SO2X Inorganic materials 0.000 description 1
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 125000002947 alkylene group Chemical group 0.000 description 1
- 239000005030 aluminium foil Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 239000002041 carbon nanotube Substances 0.000 description 1
- 229910021393 carbon nanotube Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 210000001787 dendrite Anatomy 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- 229940113088 dimethylacetamide Drugs 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000007606 doctor blade method Methods 0.000 description 1
- 238000001548 drop coating Methods 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 125000003709 fluoroalkyl group Chemical group 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 125000005843 halogen group Chemical group 0.000 description 1
- HCDGVLDPFQMKDK-UHFFFAOYSA-N hexafluoropropylene Chemical group FC(F)=C(F)C(F)(F)F HCDGVLDPFQMKDK-UHFFFAOYSA-N 0.000 description 1
- 238000010952 in-situ formation Methods 0.000 description 1
- 239000002608 ionic liquid Substances 0.000 description 1
- 229920000554 ionomer Polymers 0.000 description 1
- 238000005184 irreversible process Methods 0.000 description 1
- 239000011244 liquid electrolyte Substances 0.000 description 1
- 229940006487 lithium cation Drugs 0.000 description 1
- 229910003002 lithium salt Inorganic materials 0.000 description 1
- 159000000002 lithium salts Chemical class 0.000 description 1
- 229910001496 lithium tetrafluoroborate Inorganic materials 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
- 238000011068 loading method Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 238000005240 physical vapour deposition Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 239000005518 polymer electrolyte Substances 0.000 description 1
- 229920006254 polymer film Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- USHAGKDGDHPEEY-UHFFFAOYSA-L potassium persulfate Chemical compound [K+].[K+].[O-]S(=O)(=O)OOS([O-])(=O)=O USHAGKDGDHPEEY-UHFFFAOYSA-L 0.000 description 1
- 235000019394 potassium persulphate Nutrition 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000004626 scanning electron microscopy Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000003457 sulfones Chemical class 0.000 description 1
- 230000014233 sulfur utilization Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000010257 thawing Methods 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 238000013022 venting Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/137—Electrodes based on electro-active polymers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/20—Manufacture of shaped structures of ion-exchange resins
- C08J5/22—Films, membranes or diaphragms
- C08J5/2206—Films, membranes or diaphragms based on organic and/or inorganic macromolecular compounds
- C08J5/2218—Synthetic macromolecular compounds
- C08J5/2231—Synthetic macromolecular compounds based on macromolecular compounds obtained by reactions involving unsaturated carbon-to-carbon bonds
- C08J5/2237—Synthetic macromolecular compounds based on macromolecular compounds obtained by reactions involving unsaturated carbon-to-carbon bonds containing fluorine
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—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
- H01M10/0568—Liquid materials characterised by the solutes
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/134—Electrodes based on metals, Si or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
- H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/661—Metal or alloys, e.g. alloy coatings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/665—Composites
- H01M4/667—Composites in the form of layers, e.g. coatings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
- C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
- C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/381—Alkaline or alkaline earth metals elements
- H01M4/382—Lithium
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/581—Chalcogenides or intercalation compounds thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/417—Polyolefins
-
- 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
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Definitions
- the present invention pertains to a process for manufacturing a film, to use of said film in a process for manufacturing a lithium electrode and to use of said lithium electrode in a process for manufacturing a lithium- sulphur battery.
- Li-S batteries Rechargeable lithium-sulphur (Li-S) batteries are expected to deliver a theoretical energy density up to 2600 Wh/kg suitable for electric vehicles with a charge autonomy of 500 km or more.
- Li-S batteries are expected to deliver a theoretical energy density up to 2600 Wh/kg suitable for electric vehicles with a charge autonomy of 500 km or more.
- the commercialization of these batteries is impeded by unsolved technical problems related to the insulating nature of sulphur and to the high solubility of lithium polysulphides in the electrolyte.
- Li-S cells One of the main drawbacks related to Li-S cells is the limited cycle stability caused by irreversible processes leading to continuous loss of capacity. Particularly, the reduction of long chained lithium polysulphides on the lithium surface and the subsequent re-oxidation at the cathode, referred as polysulphide shuttle mechanism, leads to parasitic self-discharge and reduced charge efficiency. Moreover, insoluble and insulating short chained lithium polysulphides are formed on both cathode and anode surfaces.
- Another promising approach is to protect the lithium surface from reaction with polysulphides by a protective coating layer formed by a cross-linking reaction of a curable monomer in the presence of a liquid electrolyte and a photoinitiator. See, for instance, PARK, Jung-ki, et al. Electrochemical performance of lithium-sulphur batteries with protected Li anodes. Journal of Power Sources. 2003, vol.1 19-121 , p.964-972.
- Free standing membranes based on NAFION ® PFSA comprising -SO3U functional groups suitable for use as polymer electrolytes in Li-S batteries have been disclosed, for instance, in JIN, Zhaoqing, et al. Application of lithiated NAFION® PFSA ionomer film as functional separator for lithium- sulphur cells. Journal of Power Sources. 2012, vol.218, p.163-167.
- NAFION ® PFSA film having a thickness of about 1 -5 ⁇ suitable for use as cation-selective membranes for Li-S batteries have been disclosed, for instance, in ALTHUES, H., et al. Reduced polysulphide shuttle in lithium- sulphur batteries using NAFION® PFSA-based separators. Journal of Power Sources. 2014, vol.251 , p.417-422.
- the present invention pertains to a process for
- composition (C) comprising, preferably consisting of:
- polymer (F) comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)] and
- liquid medium [medium (L)] comprising at least 50% by weight, based on the total weight of said medium (L), of at least one alkyl carbonate; (ii) processing the composition (C) provided in step (i) into a film; and
- composition (C) of the invention is particularly suitable for use in a process for manufacturing a film according to the invention.
- composition (C) of the invention can be easily processed into a film thereby advantageously providing a continuous and homogeneous film.
- the present invention pertains to a film obtainable by the process of the invention.
- the film of the invention typically comprises, preferably consists of, at least one layer comprising at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a
- M is an alkaline metal [monomer (FM)].
- the film of the invention is advantageously a dense film.
- the term "dense” is intended to denote a homogeneous film having a completely uniform structure free from voids, pores or holes of finite dimensions.
- a dense film thus distinguishes from a porous film, wherein the term "
- porous is intended to denote a film containing a plurality of voids, pores or holes of finite dimensions.
- the present invention pertains to an electrode
- said current collector comprising:
- a film comprising, preferably consisting of, at least one layer comprising at least one fluoropolymer
- polymer (F) comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)].
- the current collector of the electrode of the invention typically comprises:
- a film comprising, preferably consisting of, at least one layer comprising at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)].
- the metal layer of the current collector of the electrode of the invention preferably consists of a metal selected from the group consisting of copper and stainless steel.
- the metal layer of the current collector of the electrode of the invention is typically in the form of either a metal foil or a metal grid.
- the present invention thus pertains to a process for manufacturing the electrode of the invention.
- manufacturing an electrode comprises:
- step (iv-1 ) drying the film provided in step (iii-1 ).
- the electrode obtainable by the process according to this first embodiment of the invention is advantageously the electrode of the invention.
- the current collector typically comprises:
- the metal layer of the current collector if any, preferably consists of a metal selected from the group consisting of copper and stainless steel.
- the metal layer of the current collector if any, is typically in the form of either a metal foil or a metal grid.
- manufacturing an electrode comprises: (i-2) providing a current collector comprising at least one lithium layer; (ii-2) providing a film, said film being obtainable by a process comprising:
- composition (i) providing a composition (C) as defined above;
- step (iii-2) applying the film provided in step (ii-2) onto the at least one lithium layer of the current collector provided in step (i-2).
- embodiment of the invention is advantageously the electrode of the invention.
- the current collector typically comprises:
- the metal layer of the current collector if any, preferably consists of a metal selected from the group consisting of copper and stainless steel.
- the metal layer of the current collector is typically in the form of either a metal foil or a metal grid.
- manufacturing an electrode comprises:
- composition (i) providing a composition (C) as defined above;
- embodiment of the invention is advantageously the electrode of the invention.
- the metal layer preferably consists of a metal selected from the group consisting of copper and stainless steel.
- the metal layer is typically in the form of either a metal foil or a metal grid.
- the present invention pertains to a secondary battery comprising:
- a film comprising, preferably consisting of, at least one layer comprising at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)],
- the electrode (a) of the secondary battery of the invention is
- the electrode (a) of the secondary battery of the invention typically has
- the term "secondary” is intended to denote a rechargeable battery which needs an external electrical source to recharge it.
- a battery typically undergoes an electrochemical process in an electrochemical cell wherein electrons flow from a negative electrode to a positive electrode during either charge cycles or discharge cycles.
- the term "negative electrode” is intended to denote the anode of an electrochemical cell where oxidation takes place.
- positive electrode is intended to denote the cathode of an electrochemical cell where reduction takes place.
- the term "current collector” is intended to denote an electrically conducting substrate allowing electrons to flow during either charge cycles or discharge cycles.
- the secondary battery of the invention is preferably a lithium-sulphur (Li-S) battery comprising:
- a film comprising, preferably consisting of, at least one layer comprising at least one fluoropolymer
- polymer (F) comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)],
- a positive electrode comprising a current collector, said current collector comprising at least one sulphur layer, and
- the electrode (a) of the Li-S battery of the invention is advantageously the electrode of the invention.
- the electrode (a) of the Li-S battery of the invention typically operates as a negative electrode in the Li-S battery of the invention.
- the current collector of the positive electrode (b) of the Li-S battery of the invention typically comprises:
- the current collector of the positive electrode (b) of the Li-S battery of the invention may further comprise at least one metal layer.
- the current collector of the positive electrode (b) of the Li-S battery of the invention preferably comprises:
- the sulphur layer of the positive electrode (b) of the Li-S battery of the invention is typically made from either cyclic octasulphur (Ss) or its cyclic Si2 allotrope.
- the carbon layer of the positive electrode (b) of the Li-S battery of the invention is typically made from a carbonaceous material, preferably from a carbonaceous material selected from the group consisting of carbon black, carbon nanotubes, activated carbon, graphite powder, graphite fiber and metal powders or fibers such as nickel and aluminium powders or fibers.
- the metal layer of the current collector of the positive electrode (b) of the Li-S battery of the invention if any, preferably consists of a metal selected from the group consisting of aluminium, nickel and stainless steel.
- the metal layer of the current collector of the positive electrode (b) of the Li-S battery of the invention is typically in the form of either a metal foil or a metal grid or a metal foam.
- metal layer of the current collector of the positive electrode (b) of the Li-S battery of the invention consist of aluminium, it is usually in the form of either a metal foil or a metal grid.
- metal layer of the current collector of the positive electrode (b) of the Li-S battery of the invention consist of nickel, it is usually in the form of either a metal foil or a metal grid or a metal foam.
- composition (C) of the invention is advantageously in the form of a solution.
- the term “solution” is intended to denote a uniformly dispersed mixture of at least one polymer (F), typically referred to as solute, in the medium (L), typically referred to as solvent.
- solvent is used herein in its usual meaning, that is to say that it refers to a substance capable of dissolving a solute. It is common practice to refer to a solution when the resulting mixture is clear and no phase separation is visible in the system. Phase separation is taken to be the point, often referred to as “cloud point", at which the solution becomes turbid or cloudy due to the formation of polymer aggregates or at which the solution turns into a gel.
- the medium (L) typically consists essentially of at least one alkyl
- the alkyl carbonate is typically selected from the group consisting of linear alkyl carbonates of formula (I) and cyclic alkylene carbonates of formula
- R a and Rb are independently C1-C6 alkyl groups, preferably Ci-C 4 alkyl groups, more preferably C1-C2 alkyl groups, and Rc is a hydrogen atom or a C1-C6 alkyi group, preferably a hydrogen atom or a Ci-C 4 alkyi group, more preferably a hydrogen atom or a C1-C2 alkyi group.
- the medium (L) may comprise at least 50% by weight, based on the total weight of said medium (L), of at least one linear alkyi carbonate of formula (I) as defined above and/or at least one cyclic alkylene carbonate of formula (II) as defined above.
- the alkyi carbonate is preferably selected from the group consisting of linear alkyi carbonates of formula (I) such as dimethyl carbonate or ethyl methyl carbonate and cyclic alkylene carbonates of formula (II) such as ethylene carbonate or propylene carbonate.
- the medium (L) may further comprise at least one alkyi ether.
- L typically comprises, preferably consists essentially of:
- the alkyi ether is typically selected from the group consisting of linear alkyi ethers and cyclic alkylene ethers.
- the alkyi ether is preferably selected from the group consisting of linear alkyi ethers such as 1 ,2-dimethoxyethane or tetraethylene glycol dimethyl ether and cyclic alkylene ethers such as 1 ,3-dioxolane or tetrahydrofurane.
- the medium (L) is advantageously free from water.
- the medium (L) is also advantageously free from organic solvents
- N-methyl-2-pyrrolidone dimethyl sulphoxide
- ⁇ , ⁇ -dimethyl acetamide ⁇ , ⁇ -diethyl acetamide
- dimethyl formamide diethyl formamide
- fluoropolymer is a fluoropolymer
- fluorinated monomer [monomer (F)] is hereby intended to denote an ethylenically unsaturated monomer comprising at least one fluorine atom and, optionally, at least one hydrogen atom.
- fluorinated monomer is understood to mean that the polymer (F) may comprise recurring units derived from one or more than one fluorinated monomers.
- fluorinated monomers is understood, for the purposes of the present invention, both in the plural and the singular, that is to say that they denote both one or more than one fluorinated monomers as defined above.
- the polymer (F) typically comprises recurring units deriving from:
- Non limiting examples of suitable monomers (FM) are selected from the group consisting of:
- CF2 CF(CF2) P SO3M
- p is an integer comprised between 0 and 10, preferably between 1 and 6, more preferably p is equal to 2 or 3, and M is an alkaline metal
- CF 2 CF-(OCF2CF(RFi))w-O-CF 2 (CF(RF2))ySO3M, wherein w is an integer comprised between 0 and 2, RFI and RF2, equal to or different from each other, are independently F, CI or Ci-Cio fluoroalkyl groups, optionally substituted with one or more ether oxygen atoms, y is an integer between 0 and 6, and M is an alkaline metal; preferably w is 1 , RFI is -CF3, y is 1 and RF2 is F;
- alkaline metal is intended to denote a metal selected from the group consisting of Li, Na, K, Rb and Cs.
- the alkaline metal is preferably selected from the group consisting of Li, Na and K.
- Non limiting examples of suitable monomers (F) are selected from the group consisting of:
- fluoroolefins such as tetrafluoroethylene, pentafluoropropylene, hexafluoropropylene and hexafluoroisobutylene;
- chlorotrifluoroethylene and bromotrifluoroethylene are chlorotrifluoroethylene and bromotrifluoroethylene
- each of Rf3, Rf4, Rts, Rf6, equal to or different from each other is independently a fluorine atom, a C1-C6 fluoroalkyl group, optionally comprising one or more ether oxygen atoms, e.g. -CF3, -C2F5, -C3F7, -
- the monomer (F) is preferably selected from the group consisting of:
- chlorotrifluoroethylene and/or bromotrifluoroethylene are chlorotrifluoroethylene and/or bromotrifluoroethylene;
- the monomer (F) is more preferably tetrafluoroethylene.
- the polymer (F) preferably comprises recurring units deriving from:
- the equivalent weight of the polymer (F), when converted into its acid form, is advantageously less than 1000 g/eq, preferably less than 900 g/eq, more preferably less than 800 g/eq, even more preferably less than 700 g/eq.
- the equivalent weight of the polymer (F), when converted into its acid form, is advantageously at least 400 g/eq, preferably at least 450 g/eq, more preferably at least 500 g/eq.
- the monomer (FM) is typically present in the polymer (F) in an amount such that the equivalent weight of the polymer (F), when converted into its acid form, is advantageously less than 1000 g/eq, preferably less than 900 g/eq, more preferably less than 800 g/eq, even more preferably less than 700 g/eq.
- the monomer (FM) is typically present in the polymer (F) in an amount such that the equivalent weight of the polymer (F), when converted into its acid form, is advantageously at least 400 g/eq, preferably at least 450 g/eq, more preferably at least 500 g/eq.
- the term “equivalent weight” is defined as the weight of the polymer (F) in acid form required to neutralize one equivalent of NaOH, wherein the term “acid form” means that all the functional groups of said polymer (F) are in -SO3H form.
- the polymer (F) is typically obtainable by any polymerization process known in the art.
- the polymer (F) is preferably obtainable from a fluoropolymer comprising recurring units derived from a fluorinated monomer comprising a -SO2X functional group, wherein X is a halogen atom, preferably X being a fluorine atom, by any polymerization process known in the art. Suitable processes for the preparation of such fluoropolymers are for instance those described in EP 1323751 A (SOLVAY SOLEXIS S.P.A.) 7/2/2003 and EP 1 172382 A (AUSIMONT S.P.A.) 1/16/2002 .
- composition (C) preferably comprises, more preferably consists of:
- composition (C) of at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)], and
- composition (C) from 70% to 99% by weight, preferably from 80% to 99% by weight, based on the total weight of the composition (C), of a liquid medium
- [medium (L)] comprising at least 50% by weight, based on the total weight of said medium (L), of at least one alkyl carbonate.
- step (ii) of the process for manufacturing a film according to the invention the composition (C) provided in step (i) is processed into a film typically by using any suitable techniques, preferably by tape casting, dip coating, spin coating or spray coating.
- step (iii) of the process for manufacturing a film according to the invention the film provided in step (ii) is dried typically at a temperature comprised between 25°C and 200°C.
- drying can be performed either under atmospheric pressure or under vacuum.
- drying can be performed under modified atmosphere, e.g. under an inert gas, typically exempt notably from moisture (water vapour content of less than 0.001 % v/v).
- the drying temperature will be selected so as to effect removal by evaporation of the medium (L) from the film of the invention.
- step (iii-1 ) of the process for manufacturing an electrode according to the first embodiment of the invention the composition (C) provided in step (ii-1 ) is applied onto the at least one lithium layer of the current collector provided in step (i-1 ) typically by any suitable techniques such as spin coating, spray coating, drop coating, dip coating and doctor blade, preferably by doctor blade.
- step (iv-1 ) of the process for manufacturing an electrode according to the first embodiment of the invention the film provided in step (iii-1 ) is dried typically at a temperature comprised between 25°C and 200°C.
- drying can be performed either under atmospheric pressure or under vacuum.
- drying can be performed under modified atmosphere, e.g. under an inert gas, typically exempt notably from moisture (water vapour content of less than 0.001 % v/v).
- the drying temperature will be selected so as to effect removal by evaporation of the medium (L) from the electrode of the invention.
- step (iii-2) of the process for manufacturing an electrode according to the second embodiment of the invention the film provided in step (ii-2) is applied onto the at least one lithium layer of the current collector provided in step (i-2) typically by any suitable techniques such as lamination.
- Lamination typically comprises stacking the layers thereby providing an assembly and, optionally, pressing the assembly so obtained at a temperature comprised between 20°C and 120°C.
- step (ii-3) of the process for manufacturing an electrode according to the third embodiment of the invention at least one lithium layer is deposited onto the film provided in step (i-3) typically by any suitable techniques such as physical vapour deposition, in particular vacuum evaporation deposition, or electroless deposition, preferably by vacuum evaporation deposition.
- Vacuum evaporation deposition typically comprises heating a metal source such as a lithium source above its melting temperature in a vacuum chamber thereby providing evaporated metal particles which then typically condense to a solid state onto a substrate.
- Electroless deposition is typically carried out in a plating bath wherein a lithium cation of a lithium salt is reduced from its oxidation state to its elemental state in the presence of suitable chemical reducing agents.
- At least one metal layer may be applied onto the at least one lithium layer provided in step (ii-3) by any suitable techniques such as lamination.
- Lamination typically comprises stacking the layers thereby providing an assembly and, optionally, pressing the assembly so obtained at a temperature comprised between 20°C and 120°C.
- the term "separator” is intended to denote a film which is capable of physically and electrically separating the anode from the cathode of the electrochemical cell, while permitting electrolyte ions to flow there through.
- the separator (c) of the secondary battery of the invention is typically
- the separator (c) of the secondary battery of the invention is typically a porous separator.
- the separator (c) of the secondary battery of the invention is typically
- polystyrene resin made from a polyolefin, preferably made from polyethylene or
- the secondary battery of the invention is typically filled with an electrolyte medium [medium (E)].
- the medium (E) typically comprises a metal salt.
- the metal salt is typically selected from the group consisting of Mel, Me(PF6) n , Me(BF 4 ) n , Me(CIO 4 ) n , Me(bis(oxalato)borate) n ("Me(BOB) n "), MeCF 3 SO 3 , Me[N(CF 3 SO 2 )2] n , Me[N(C 2 F 5 SO2)2]n, Me[N(CF 3 SO2)(RFSO 2 )]n with R F being C 2 F 5 , C 4 F 9 , CF3OCF2CF2, Me(AsF 6 ) n , Me[C(CF 3 SO 2 )3]n, Me 2 S n , wherein Me is a metal, preferably a transition metal, an alkaline metal or an alkaline-earth metal, more preferably Me being Li, Na, K, Cs, and n is the valence of said metal, typically n being
- the metal salt is preferably selected from the group consisting of Lil,
- LiPF 6 LiBF 4 , LiCIO 4 , lithium bis(oxalato)borate (“LiBOB”), UCF3SO3, LiN(CF 3 SO 2 )2, LiN(C 2 F 5 SO 2 )2, M[N(CF 3 SO 2 )(R F SO 2 )] n with R F being C 2 F 5 , C F 9 , CF 3 OCF 2 CF 2 , LiAsFe, LiC(CF 3 SO 2 ) 3 , Li 2 S n and combinations thereof.
- LiBOB lithium bis(oxalato)borate
- the medium (E) typically further comprises at least one organic solvent selected from the group consisting of alkyl carbonates, alkyl ethers, sulfones, ionic liquids, fluorinated alkyl carbonates and fluorinated alkyl ethers.
- the medium (E) may further comprise at least one polysulphide of formula Li 2 S n , wherein n is equal to 1 or higher than 1 , preferably n being comprised between 1 and 12.
- the autoclave stirred at 470 rpm, was heated to a temperature of 60°C and then 150 ml of a water solution containing 6 g/litre of potassium persulphate was added.
- the pressure was maintained at a value of 12 absolute bar by introducing tetrafluoroethylene (TFE).
- TFE tetrafluoroethylene
- a latex with a concentration of 28% by weight was obtained.
- the remaining amount of latex was kept under nitrogen bubbling for 16 hours to strip away residual monomers from the polymerization and then frozen in a plastic tank for 48 hours. After evaporation of the water, the coagulated polymer precursor was washed several times with
- the polymer was then treated with a mixture of nitrogen and fluorine gas (50/50) in a Monel reactor at 80°C and ambient pressure for 10 hours with a gas flow of 5 Nl/hour, and then dried in a ventilated oven at 80°C for 24 hours.
- the polymer precursor in -SO2F form so obtained was treated for 10 hours with a NaOH solution (10% by weight of NaOH, 10 litre of solution per Kg of polymer) at 80°C and then washed several times with demineralized water until the pH of the water was less than 9.
- the polymer was then treated with HNO3 (20% by weight) in order to obtain complete exchange to -SO3H form.
- the polymer was rinsed with water and dried in ventilated oven at 80°C for 20 hours.
- a film was prepared from a sample of dry polymer obtained following procedure (A) as detailed hereinabove by heating the powder in a press at 270°C for 5 min.
- a film sample (10 cm x 10 cm) was cut and treated with a 10% by weight KOH solution in water for 24 hours at 80°C and then, after washing with pure water, with a 20% by weight HNO3 solution at ambient temperature. The film was finally washed with water. Using this procedure the functional groups of the polymer were converted from the -SO2F form to -SO3H form.
- a solution containing 5% by weight of polymer (F-1 ) having an equivalent weight of 660 g/eq in propylene carbonate was prepared after 4 hours under stirring at 80°C.
- the solution so obtained was clear and
- a solution containing 10% by weight of polymer (F-1 ) having an equivalent weight of 870 g/eq in propylene carbonate was prepared after 4 hours under stirring at 80°C. The solution so obtained was clear and
- a film having a thickness of 20 pm was manufactured using the solution prepared according to Example 1 by tape casting and drying (48 hours under vacuum at 120°C).
- a lithium electrode was prepared using a current collector comprising a lithium foil which was cut in the desired dimensions.
- the solution prepared according to Example 1 was then coated by doctor blade technique onto the lithium foil of the current collector and then dried at 60°C (firstly under argon, then under vacuum) thereby providing a protective layer having a final thickness of about 30 pm.
- the assembly so obtained was cut thereby providing a negative electrode comprising a lithium layer having a diameter of 14 mm and, adhered to said lithium layer, a protective film having a diameter of 16 mm.
- the film prepared according to Example 3 was dried under vacuum to remove water traces. Lithium metal deposition with thicknesses up to about 1 pm was performed on the film by vacuum evaporation technique. The lithium/protective film stack was then cut into a lithium electrode.
- a sulphur cathode was prepared by mixing carbon black powder (10% by weight), sulphur powder (80% by weight) and a polyvinylidene fluoride binder (10% by weight) in N-methyl-2-pyrrolidone. The slurry was then coated onto an aluminium foil of 20 ⁇ to a thickness of 100 ⁇ . After drying at 55°C, the thickness of the electrode was about 15 ⁇ , with a loading of sulphur of about 1.8 mg/cm 2 .
- a coin cell was assembled under controlled atmosphere in a glove box.
- the lithium electrode prepared according to Example 4 was cut into a 14 mm disk and then dried under vacuum.
- An assembly was prepared using a CR2032 coin cell casing, said assembly comprising, in succession, a sulphur positive electrode having a diameter of 14 mm, a porous separator made of polypropylene having a diameter of 16.5 mm and the negative electrode prepared according to Example 4.
- LiTFSI lithium bis(trifluoromethanesulfonyl)imide
- TEGDME tetraethylene glycol dimethyl ether
- DIOX tetraethylene glycol dimethyl ether
- a coin cell was assembled under controlled atmosphere in a glove box.
- the film prepared according to Example 3 was cut into a 16.5 mm disk and then dried under vacuum.
- An assembly was prepared using a CR2032 coin cell casing, said assembly comprising, in succession, a sulphur positive electrode having a diameter of 14 mm, a porous separator made of polypropylene having a diameter of 16.5 mm, the film prepared according to Example 3 having a diameter of 16.5 mm and a lithium electrode having a diameter of 16 mm.
- LiTFSI lithium bis(trifluoromethanesulfonyl)imide
- TEGDME tetraethylene glycol dimethyl ether
- DIOX tetraethylene glycol dimethyl ether
- a mixture comprising 10.4% by weight of polymer (F-1 ) having an equivalent weight of 790, 75.0% by weight of water and 14.6% by weight of n-propanol was prepared and subsequently dropped onto a circular sample of porous separator made of polypropylene (weight: 170 mg, area: 95 cm 2 , thickness: 30 ⁇ ) at room temperature.
- the wet separator so obtained was then dried in an oven using the following temperature program: 1.5 hours at 65°C, 1.5 hours at 90°C and 15 minutes at 160°C. After drying, the weight increase and the SEM analysis confirmed the presence of a dense and homogeneous polymer film covering the pores initially present on the polypropylene support (0.25 mg/cm 2 on each side).
- An assembly was prepared using a CR2032 coin cell casing, said assembly comprising, in succession, a sulphur positive electrode having a diameter of 14 mm, the separator so obtained having a diameter of 16.5 mm and a lithium electrode having a diameter of 16 mm.
- An electrolyte medium containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) 1 M in tetraethylene glycol dimethyl ether (TEGDME)/1 ,3-dioxolane (DIOX) (50/50 by volume) was impregnated into the cell so obtained. The cell was then sealed in the glove box and then cycled between 1.5 V and 3 V vs. Li+/Li at C/10.
- a coin cell was assembled under controlled atmosphere in a glove box.
- An assembly was prepared using a CR2032 coin cell casing, said assembly comprising, in succession, a sulphur positive electrode having a diameter of 14 mm, a porous separator made of polypropylene having a diameter of 16.5 mm and a lithium electrode having a diameter of 16 mm.
- An electrolyte medium containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) 1 M in tetraethylene glycol dimethyl ether (TEGDME)/1 ,3- dioxolane (DIOX) (50/50 by volume) was impregnated into the cell so obtained.
- the cell was then sealed in the glove box and then cycled between 1.5 V and 3 V vs. Li+/Li at C/10.
- a Li/S cell was prepared following the same procedure as detailed under Example 6 but using the lithium electrode prepared according to
- a Li/S cell was prepared following the same procedure as detailed under Example 6 but using the lithium electrode prepared according to
- Electrochemical measurements were performed in CR2032 coin cells at room temperature and C/100 between 1.5V and 3V.
- the specific discharge capacity values [mAh/g of S] are representative of the percentage of sulphur utilization in the Li-S coin cells.
- the capacity retention values [%] are representative of the retention of the initial specific discharge capacity values upon charge/discharge cycles of the Li-S coin cells. The higher the capacity retention values, the better the cycle life of the cell.
- the columbic efficiency values [%] are representative of the fraction of the electrical charge stored during charging that is recoverable during discharge.
- the Li-S coin cells of Example 7 according to the invention successfully exhibited both higher specific discharge capacity values and higher columbic efficiency values as compared to conventional Li-S batteries as notably embodied by any of the Li-S coin cells of Comparative Examples 5, 6, 7 and 8.
- the Li-S coin cells of Example 7 according to the invention successfully exhibited good or higher capacity retention values as compared to conventional Li-S batteries as notably embodied by the Li-S coin cell of Comparative Example 5.
- the Li-S battery of the invention successfully exhibited absent or reduced polysulphide shuttle mechanism, while maintaining good or increased capacity values, as compared to conventional Li-S batteries.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Composite Materials (AREA)
- Inorganic Chemistry (AREA)
- Medicinal Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Cell Electrode Carriers And Collectors (AREA)
Abstract
The present invention pertains to a process for manufacturing a film, said process comprising: (i) providing a composition [composition (C)] comprising, preferably consisting of: - at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO 3 M functional group, wherein M is an alkaline metal [monomer (FM)] and - a liquid medium [medium (L)] comprising at least 50% by weight, based on the total weight of said medium (L), of at least one alkyl carbonate; (ii) processing the composition (C) provided in step (i) into a film; and (iii) drying the film provided in step (ii). The present invention further pertains to use of said film in a process for manufacturing a lithium electrode and to use of said lithium electrode in a process for manufacturing a lithium-sulphur battery.
Description
Description
Lithium electrodes for lithium-sulphur batteries Cross-reference to related application
[0001] This application claims priority to European application No. 14306878.1 filed on November 25, 2014, the whole content of this application being incorporated herein by reference for all purposes.
Technical Field
[0002] The present invention pertains to a process for manufacturing a film, to use of said film in a process for manufacturing a lithium electrode and to use of said lithium electrode in a process for manufacturing a lithium- sulphur battery.
Background Art
[0003] Sulphur is abundant, cheap and nontoxic. Rechargeable lithium-sulphur (Li-S) batteries are expected to deliver a theoretical energy density up to 2600 Wh/kg suitable for electric vehicles with a charge autonomy of 500 km or more. However, the commercialization of these batteries is impeded by unsolved technical problems related to the insulating nature of sulphur and to the high solubility of lithium polysulphides in the electrolyte.
Different strategies have been proposed to improve the electrochemical performance of the Li-S battery by special designs of the cathode structure, electrolyte composition and anode protection.
[0004] One of the main drawbacks related to Li-S cells is the limited cycle stability caused by irreversible processes leading to continuous loss of capacity. Particularly, the reduction of long chained lithium polysulphides on the lithium surface and the subsequent re-oxidation at the cathode, referred as polysulphide shuttle mechanism, leads to parasitic self-discharge and reduced charge efficiency. Moreover, insoluble and insulating short chained lithium polysulphides are formed on both cathode and anode surfaces.
[0005] Different attempts have been investigated to encapsulate polysulphides in the cathode.
[0006] Another promising approach is to protect the lithium surface from reaction with polysulphides by a protective coating layer formed by a cross-linking
reaction of a curable monomer in the presence of a liquid electrolyte and a photoinitiator. See, for instance, PARK, Jung-ki, et al. Electrochemical performance of lithium-sulphur batteries with protected Li anodes. Journal of Power Sources. 2003, vol.1 19-121 , p.964-972.
[0007] Also, another approach is to promote the in situ formation of a stable solid electrolyte interface (SEI) layer by application of L1NO3 electrolyte additive. Unfortunately, L1NO3 is consumed during SEI formation on lithium and therefore has no enduring effect on charge efficiency due to formation of lithium dendrites upon cycling. It is also reported that L1NO3 decomposes in Li-S cells at voltages below 1.6 V vs. Li/Li+.
[0008] Moreover, it is possible to transform the separator into an ion selective barrier being impermeable to polysulphides but permeable to lithium ions in order to suppress the shuttle mechanism.
[0009] Free standing membranes based on NAFION® PFSA comprising -SO3U functional groups suitable for use as polymer electrolytes in Li-S batteries have been disclosed, for instance, in JIN, Zhaoqing, et al. Application of lithiated NAFION® PFSA ionomer film as functional separator for lithium- sulphur cells. Journal of Power Sources. 2012, vol.218, p.163-167.
[0010] Further, CELGARD® 2500 polypropylene separators coated with a Li-
NAFION® PFSA film having a thickness of about 1 -5 μηη suitable for use as cation-selective membranes for Li-S batteries have been disclosed, for instance, in ALTHUES, H., et al. Reduced polysulphide shuttle in lithium- sulphur batteries using NAFION® PFSA-based separators. Journal of Power Sources. 2014, vol.251 , p.417-422.
Summary of invention
[001 1] In a first instance, the present invention pertains to a process for
manufacturing a film, said process comprising:
(i) providing a composition (C) comprising, preferably consisting of:
- at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)] and
- a liquid medium [medium (L)] comprising at least 50% by weight, based on the total weight of said medium (L), of at least one alkyl carbonate;
(ii) processing the composition (C) provided in step (i) into a film; and
(iii) drying the film provided in step (ii).
[0012] The composition (C) of the invention is particularly suitable for use in a process for manufacturing a film according to the invention.
[0013] It has been found that the composition (C) of the invention can be easily processed into a film thereby advantageously providing a continuous and homogeneous film.
[0014] In a second instance, the present invention pertains to a film obtainable by the process of the invention.
[0015] The film of the invention typically comprises, preferably consists of, at least one layer comprising at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a
-SO3M functional group, wherein M is an alkaline metal [monomer (FM)].
[0016] The film of the invention is advantageously a dense film.
[0017] For the purpose of the present invention, the term "dense" is intended to denote a homogeneous film having a completely uniform structure free from voids, pores or holes of finite dimensions.
[0018] A dense film thus distinguishes from a porous film, wherein the term "
porous" is intended to denote a film containing a plurality of voids, pores or holes of finite dimensions.
[0019] In a third instance, the present invention pertains to an electrode
comprising a current collector, said current collector comprising:
- at least one lithium layer, and
- adhered to said at least one lithium layer, a film comprising, preferably consisting of, at least one layer comprising at least one fluoropolymer
[polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)].
[0020] The current collector of the electrode of the invention typically comprises:
- at least one metal layer,
- adhered to said at least one metal layer, at least one lithium layer, and
- adhered to said at least one lithium layer, a film comprising, preferably consisting of, at least one layer comprising at least one fluoropolymer
[polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)].
[0021] The metal layer of the current collector of the electrode of the invention preferably consists of a metal selected from the group consisting of copper and stainless steel.
[0022] The metal layer of the current collector of the electrode of the invention is typically in the form of either a metal foil or a metal grid.
[0023] In a fourth instance, the present invention thus pertains to a process for manufacturing the electrode of the invention.
[0024] According to a first embodiment of the invention, the process for
manufacturing an electrode comprises:
(i-1 ) providing a current collector comprising at least one lithium layer; (ii-1 ) providing a composition (C) as defined above;
(iii-1 ) applying the composition (C) provided in step (ii-1 ) onto the at least one lithium layer of the current collector provided in step (i-1 ) thereby providing a film; and
(iv-1 ) drying the film provided in step (iii-1 ).
[0025] The electrode obtainable by the process according to this first embodiment of the invention is advantageously the electrode of the invention.
[0026] Under step (i-1 ) of the process according to this first embodiment of the invention, the current collector typically comprises:
- at least one metal layer, and
- adhered to said at least one metal layer, at least one lithium layer.
[0027] Under step (i-1 ) of the process according to this first embodiment of the invention, the metal layer of the current collector, if any, preferably consists of a metal selected from the group consisting of copper and stainless steel.
[0028] Under step (i-1 ) of the process according to this first embodiment of the invention, the metal layer of the current collector, if any, is typically in the form of either a metal foil or a metal grid.
[0029] According to a second embodiment of the invention, the process for
manufacturing an electrode comprises:
(i-2) providing a current collector comprising at least one lithium layer; (ii-2) providing a film, said film being obtainable by a process comprising:
(i) providing a composition (C) as defined above;
(ii) processing the composition (C) provided in step (i) into a film; and
(iii) drying the film provided in step (ii); and
(iii-2) applying the film provided in step (ii-2) onto the at least one lithium layer of the current collector provided in step (i-2).
[0030] The electrode obtainable by the process according to this second
embodiment of the invention is advantageously the electrode of the invention.
[0031] Under step (i-2) of the process according to this second embodiment of the invention, the current collector typically comprises:
- at least one metal layer, and
- adhered to said at least one metal layer, at least one lithium layer.
[0032] Under step (i-2) of the process according to this second embodiment of the invention, the metal layer of the current collector, if any, preferably consists of a metal selected from the group consisting of copper and stainless steel.
[0033] Under step (i-2) of the process according to this second embodiment of the invention, the metal layer of the current collector, if any, is typically in the form of either a metal foil or a metal grid.
[0034] According to a third embodiment of the invention, the process for
manufacturing an electrode comprises:
(i-3) providing a film, said film being obtainable by a process comprising:
(i) providing a composition (C) as defined above;
(ii) processing the composition (C) provided in step (i) into a film; and
(iii) drying the film provided in step (ii);
(ii-3) depositing at least one lithium layer onto the film provided in step (i- 3); and
(iii-3) optionally, applying at least one metal layer onto the at least one lithium layer provided in step (ii-3).
[0035] The electrode obtainable by the process according to this third
embodiment of the invention is advantageously the electrode of the invention.
[0036] Under step (iii-3) of the process according to this third embodiment of the invention, if any, the metal layer preferably consists of a metal selected from the group consisting of copper and stainless steel.
[0037] Under step (iii-3) of the process according to this third embodiment of the invention, if any, the metal layer is typically in the form of either a metal foil or a metal grid.
[0038] In a fifth instance, the present invention pertains to a secondary battery comprising:
(a) an electrode comprising a current collector, said current collector comprising:
- at least one lithium layer, and
- adhered to said at least one lithium layer, a film comprising, preferably consisting of, at least one layer comprising at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)],
(b) a positive electrode, and
(c) a separator.
[0039] The electrode (a) of the secondary battery of the invention is
advantageously the electrode of the invention.
[0040] The electrode (a) of the secondary battery of the invention typically
operates as a negative electrode in the secondary battery of the invention.
[0041] The positive electrode (b) of the secondary battery of the invention
typically comprises a current collector.
[0042] For the purpose of the present invention, the term "secondary" is intended to denote a rechargeable battery which needs an external electrical source to recharge it. A battery typically undergoes an electrochemical process in an electrochemical cell wherein electrons flow from a negative electrode to a positive electrode during either charge cycles or discharge cycles.
[0043] For the purpose of the present invention, the term "negative electrode" is intended to denote the anode of an electrochemical cell where oxidation takes place.
[0044] For the purpose of the present invention, the term "positive electrode" is intended to denote the cathode of an electrochemical cell where reduction takes place.
[0045] For the purpose of the present invention, the term "current collector" is intended to denote an electrically conducting substrate allowing electrons to flow during either charge cycles or discharge cycles.
[0046] The secondary battery of the invention is preferably a lithium-sulphur (Li-S) battery comprising:
(a) an electrode comprising a current collector, said current collector comprising:
- at least one lithium layer, and
- adhered to said at least one lithium layer, a film comprising, preferably consisting of, at least one layer comprising at least one fluoropolymer
[polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)],
(b) a positive electrode comprising a current collector, said current collector comprising at least one sulphur layer, and
(c) a separator.
[0047] The electrode (a) of the Li-S battery of the invention is advantageously the electrode of the invention.
[0048] The electrode (a) of the Li-S battery of the invention typically operates as a negative electrode in the Li-S battery of the invention.
[0049] It has been surprisingly found that the Li-S battery of the invention
advantageously exhibits absent or reduced polysulphide shuttle
mechanism, while maintaining good or increased capacity values, as compared to conventional Li-S batteries.
[0050] The Applicant thinks, without this limiting the scope of the invention, that this is due to the inherent structure of the electrode of the invention, said
electrode being obtainable from the composition (C) according to the process of the invention.
[0051] The current collector of the positive electrode (b) of the Li-S battery of the invention typically comprises:
- at least one carbon layer, and
- adhered to said at least one carbon layer, at least one sulphur layer.
[0052] The current collector of the positive electrode (b) of the Li-S battery of the invention may further comprise at least one metal layer.
[0053] The current collector of the positive electrode (b) of the Li-S battery of the invention preferably comprises:
- at least one metal layer,
- adhered to said at least one metal layer, at least one carbon layer and,
- adhered to said at least one carbon layer, at least one sulphur layer.
[0054] The sulphur layer of the positive electrode (b) of the Li-S battery of the invention is typically made from either cyclic octasulphur (Ss) or its cyclic Si2 allotrope.
[0055] The carbon layer of the positive electrode (b) of the Li-S battery of the invention, if any, is typically made from a carbonaceous material, preferably from a carbonaceous material selected from the group consisting of carbon black, carbon nanotubes, activated carbon, graphite powder, graphite fiber and metal powders or fibers such as nickel and aluminium powders or fibers.
[0056] The metal layer of the current collector of the positive electrode (b) of the Li-S battery of the invention, if any, preferably consists of a metal selected from the group consisting of aluminium, nickel and stainless steel.
[0057] The metal layer of the current collector of the positive electrode (b) of the Li-S battery of the invention, if any, is typically in the form of either a metal foil or a metal grid or a metal foam.
[0058] Should the metal layer of the current collector of the positive electrode (b) of the Li-S battery of the invention consist of aluminium, it is usually in the form of either a metal foil or a metal grid.
[0059] Should the metal layer of the current collector of the positive electrode (b) of the Li-S battery of the invention consist of nickel, it is usually in the form of either a metal foil or a metal grid or a metal foam.
[0060] The composition (C) of the invention is advantageously in the form of a solution.
[0061] For the purpose of the present invention, the term "solution" is intended to denote a uniformly dispersed mixture of at least one polymer (F), typically referred to as solute, in the medium (L), typically referred to as solvent. The term "solvent" is used herein in its usual meaning, that is to say that it refers to a substance capable of dissolving a solute. It is common practice to refer to a solution when the resulting mixture is clear and no phase separation is visible in the system. Phase separation is taken to be the point, often referred to as "cloud point", at which the solution becomes turbid or cloudy due to the formation of polymer aggregates or at which the solution turns into a gel.
[0062] The medium (L) typically consists essentially of at least one alkyl
carbonate.
[0063] The alkyl carbonate is typically selected from the group consisting of linear alkyl carbonates of formula (I) and cyclic alkylene carbonates of formula
(II):
Ra and Rb, equal to or different from each other, are independently C1-C6 alkyl groups, preferably Ci-C4 alkyl groups, more preferably C1-C2 alkyl groups, and
Rc is a hydrogen atom or a C1-C6 alkyi group, preferably a hydrogen atom or a Ci-C4 alkyi group, more preferably a hydrogen atom or a C1-C2 alkyi group.
[0064] The medium (L) may comprise at least 50% by weight, based on the total weight of said medium (L), of at least one linear alkyi carbonate of formula (I) as defined above and/or at least one cyclic alkylene carbonate of formula (II) as defined above.
[0065] The alkyi carbonate is preferably selected from the group consisting of linear alkyi carbonates of formula (I) such as dimethyl carbonate or ethyl methyl carbonate and cyclic alkylene carbonates of formula (II) such as ethylene carbonate or propylene carbonate.
[0066] The medium (L) may further comprise at least one alkyi ether.
[0067] Should the medium (L) further comprise at least one alkyi ether, said
medium (L) typically comprises, preferably consists essentially of:
- at least 50% by weight, based on the total weight of said medium (L), of at least one alkyi carbonate, and
- at most 50% by weight, based on the total weight of said medium (L), of at least one alkyi ether.
[0068] The alkyi ether is typically selected from the group consisting of linear alkyi ethers and cyclic alkylene ethers.
[0069] The alkyi ether is preferably selected from the group consisting of linear alkyi ethers such as 1 ,2-dimethoxyethane or tetraethylene glycol dimethyl ether and cyclic alkylene ethers such as 1 ,3-dioxolane or tetrahydrofurane.
[0070] The medium (L) is advantageously free from water.
[0071] The medium (L) is also advantageously free from organic solvents
selected from the group consisting of N-methyl-2-pyrrolidone, dimethyl sulphoxide, Ν,Ν-dimethyl acetamide, Ν,Ν-diethyl acetamide, dimethyl formamide and diethyl formamide.
[0072] For the purpose of the present invention, the term "fluoropolymer" is
intended to denote a polymer comprising a backbone comprising recurring units derived from at least fluorinated monomer [monomer (F)].
[0073] The term "fluorinated monomer [monomer (F)]" is hereby intended to denote an ethylenically unsaturated monomer comprising at least one fluorine atom and, optionally, at least one hydrogen atom.
[0074] The term "at least one fluorinated monomer" is understood to mean that the polymer (F) may comprise recurring units derived from one or more than one fluorinated monomers. In the rest of the text, the expression " fluorinated monomers" is understood, for the purposes of the present invention, both in the plural and the singular, that is to say that they denote both one or more than one fluorinated monomers as defined above.
[0075] The polymer (F) typically comprises recurring units deriving from:
- at least one fluorinated monomer comprising at least one -SO3M functional group, wherein M is an alkaline metal [monomer (FM)], and
- at least one fluorinated monomer [monomer (F)].
[0076] Non limiting examples of suitable monomers (FM) are selected from the group consisting of:
- sulfonyl halide fluoroolefins of formula CF2=CF(CF2)PSO3M, wherein p is an integer comprised between 0 and 10, preferably between 1 and 6, more preferably p is equal to 2 or 3, and M is an alkaline metal;
- sulfonyl halide fluorovinylethers of formula CF2=CF-O-(CF2)mSO3M, wherein m is an integer comprised between 1 and 10, preferably between 1 and 6, more preferably between 2 and 4, even more preferably m is equal to 2, and M is an alkaline metal;
- sulfonyl halide fluoroalkoxyvinylethers of formula
CF2=CF-(OCF2CF(RFi))w-O-CF2(CF(RF2))ySO3M, wherein w is an integer comprised between 0 and 2, RFI and RF2, equal to or different from each other, are independently F, CI or Ci-Cio fluoroalkyl groups, optionally substituted with one or more ether oxygen atoms, y is an integer between 0 and 6, and M is an alkaline metal; preferably w is 1 , RFI is -CF3, y is 1 and RF2 is F;
- sulfonyl halide aromatic fluoroolefins of formula CF2=CF-Ar-SO3M, wherein Ar is a C5-C15 aromatic or heteroaromatic substituent and M is an alkaline metal.
[0077] For the purpose of the present invention, the term "alkaline metal" is intended to denote a metal selected from the group consisting of Li, Na, K, Rb and Cs. The alkaline metal is preferably selected from the group consisting of Li, Na and K.
[0078] The monomer (FM) is preferably selected from the group consisting of fluorovinylethers of formula CF2=CF-O-(CF2)m-SO3Li, wherein m is an integer comprised between 1 and 6, preferably between 2 and 4.
[0079] The monomer (FM) is more preferably CF2=CF-OCF2CF2-SO3Li.
[0080] Non limiting examples of suitable monomers (F) are selected from the group consisting of:
- C2-C8 fluoroolefins, such as tetrafluoroethylene, pentafluoropropylene, hexafluoropropylene and hexafluoroisobutylene;
- vinylidene fluoride;
- C2-C8 chloro- and/or bromo- and/or iodo-fluoroolefins, such as
chlorotrifluoroethylene and bromotrifluoroethylene;
- fluoroalkylvinylethers of formula CF2=CFORfi , wherein Rfi is a C1-C6 fluoroalkyl, e.g. -CF3, -C2F5, -C3F7;
- fluoro-oxyalkylvinylethers of formula CF2=CFORoi , wherein R01 is a Ci- C12 fluoro-oxyalkyl group having one or more ether groups, e.g. perfluoro- 2-propoxy-propyl group;
- fluoroalkyl-methoxy-vinylethers of formula CF2=CFOCF2ORf2, wherein Rf2 is a C1-C6 fluoroalkyl group, e.g. -CF3, -C2F5, -C3F7, or a C1-C6 fluorooxyalkyl group having one or more ether groups, e.g. -C2F5-O-CF3;
- fluorodioxoles of formula:
wherein each of Rf3, Rf4, Rts, Rf6, equal to or different from each other, is
independently a fluorine atom, a C1-C6 fluoroalkyl group, optionally comprising one or more ether oxygen atoms, e.g. -CF3, -C2F5, -C3F7, -
[0081] The monomer (F) is preferably selected from the group consisting of:
- C2-C8 fluoroolefins, preferably tetrafluoroethylene and/or
hexafluoropropylene;
- chloro- and/or bromo- and/or iodo-C2-C6 fluoroolefins, such as
chlorotrifluoroethylene and/or bromotrifluoroethylene;
- fluoroalkylvinylethers of formula CF2=CFORfi , wherein Rfi is a C1-C6 fluoroalkyl group, e.g. -CF3, -C2F5, -C3F7;
- fluoro-oxyalkylvinylethers of formula CF2=CFORoi , wherein R01 is a Ci- C12 fluorooxyalkyl group having one or more ether groups, e.g. perfluoro- 2-propoxy-propyl group.
[0082] The monomer (F) is more preferably tetrafluoroethylene.
[0083] The polymer (F) preferably comprises recurring units deriving from:
- at least one monomer (FM) selected from the group consisting of fluorovinylethers of formula CF2=CF-O-(CF2)m-SO3Li, wherein m is an integer between 1 and 6, preferably between 2 and 4, and
- tetrafluoroethylene.
[0084] The equivalent weight of the polymer (F), when converted into its acid form, is advantageously less than 1000 g/eq, preferably less than 900 g/eq, more preferably less than 800 g/eq, even more preferably less than 700 g/eq. The equivalent weight of the polymer (F), when converted into its acid form, is advantageously at least 400 g/eq, preferably at least 450 g/eq, more preferably at least 500 g/eq.
[0085] The monomer (FM) is typically present in the polymer (F) in an amount such that the equivalent weight of the polymer (F), when converted into its acid form, is advantageously less than 1000 g/eq, preferably less than 900 g/eq, more preferably less than 800 g/eq, even more preferably less than 700 g/eq. The monomer (FM) is typically present in the polymer (F) in an amount such that the equivalent weight of the polymer (F), when converted into its acid form, is advantageously at least 400 g/eq, preferably at least 450 g/eq, more preferably at least 500 g/eq.
[0086] For the purpose of the present invention, the term "equivalent weight" is defined as the weight of the polymer (F) in acid form required to neutralize one equivalent of NaOH, wherein the term "acid form" means that all the functional groups of said polymer (F) are in -SO3H form.
[0087] The polymer (F) is typically obtainable by any polymerization process known in the art.
[0088] The polymer (F) is preferably obtainable from a fluoropolymer comprising recurring units derived from a fluorinated monomer comprising a -SO2X functional group, wherein X is a halogen atom, preferably X being a fluorine atom, by any polymerization process known in the art. Suitable processes for the preparation of such fluoropolymers are for instance those described in EP 1323751 A (SOLVAY SOLEXIS S.P.A.) 7/2/2003 and EP 1 172382 A (AUSIMONT S.P.A.) 1/16/2002 .
[0089] The composition (C) preferably comprises, more preferably consists of:
- from 1 % to 30% by weight, preferably from 1 % to 20% by weight, based on the total weight of the composition (C), of at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)], and
- from 70% to 99% by weight, preferably from 80% to 99% by weight, based on the total weight of the composition (C), of a liquid medium
[medium (L)] comprising at least 50% by weight, based on the total weight of said medium (L), of at least one alkyl carbonate.
[0090] Under step (ii) of the process for manufacturing a film according to the invention, the composition (C) provided in step (i) is processed into a film typically by using any suitable techniques, preferably by tape casting, dip coating, spin coating or spray coating.
[0091] Under step (iii) of the process for manufacturing a film according to the invention, the film provided in step (ii) is dried typically at a temperature comprised between 25°C and 200°C.
[0092] Under step (iii) of the process for manufacturing a film according to the invention, drying can be performed either under atmospheric pressure or under vacuum. Alternatively, drying can be performed under modified
atmosphere, e.g. under an inert gas, typically exempt notably from moisture (water vapour content of less than 0.001 % v/v). The drying temperature will be selected so as to effect removal by evaporation of the medium (L) from the film of the invention.
[0093] Under step (iii-1 ) of the process for manufacturing an electrode according to the first embodiment of the invention, the composition (C) provided in step (ii-1 ) is applied onto the at least one lithium layer of the current collector provided in step (i-1 ) typically by any suitable techniques such as spin coating, spray coating, drop coating, dip coating and doctor blade, preferably by doctor blade.
[0094] Under step (iv-1 ) of the process for manufacturing an electrode according to the first embodiment of the invention, the film provided in step (iii-1 ) is dried typically at a temperature comprised between 25°C and 200°C.
[0095] Under step (iv-1 ) of the process for manufacturing an electrode according to the first embodiment of the invention, drying can be performed either under atmospheric pressure or under vacuum. Alternatively, drying can be performed under modified atmosphere, e.g. under an inert gas, typically exempt notably from moisture (water vapour content of less than 0.001 % v/v). The drying temperature will be selected so as to effect removal by evaporation of the medium (L) from the electrode of the invention.
[0096] Under step (iii-2) of the process for manufacturing an electrode according to the second embodiment of the invention, the film provided in step (ii-2) is applied onto the at least one lithium layer of the current collector provided in step (i-2) typically by any suitable techniques such as lamination.
[0097] Lamination typically comprises stacking the layers thereby providing an assembly and, optionally, pressing the assembly so obtained at a temperature comprised between 20°C and 120°C.
[0098] Under step (ii-3) of the process for manufacturing an electrode according to the third embodiment of the invention, at least one lithium layer is deposited onto the film provided in step (i-3) typically by any suitable techniques such as physical vapour deposition, in particular vacuum
evaporation deposition, or electroless deposition, preferably by vacuum evaporation deposition.
[0099] Vacuum evaporation deposition typically comprises heating a metal source such as a lithium source above its melting temperature in a vacuum chamber thereby providing evaporated metal particles which then typically condense to a solid state onto a substrate.
[0100] Electroless deposition is typically carried out in a plating bath wherein a lithium cation of a lithium salt is reduced from its oxidation state to its elemental state in the presence of suitable chemical reducing agents.
[0101] Under step (iii-3) of the process for manufacturing an electrode according to the third embodiment of the invention, at least one metal layer may be applied onto the at least one lithium layer provided in step (ii-3) by any suitable techniques such as lamination.
[0102] Lamination typically comprises stacking the layers thereby providing an assembly and, optionally, pressing the assembly so obtained at a temperature comprised between 20°C and 120°C.
[0103] For the purpose of the present invention, the term "separator" is intended to denote a film which is capable of physically and electrically separating the anode from the cathode of the electrochemical cell, while permitting electrolyte ions to flow there through.
[0104] The separator (c) of the secondary battery of the invention is typically
adhered between the film of the electrode (a) and the positive electrode
(b).
[0105] The separator (c) of the secondary battery of the invention is typically a porous separator.
[0106] The separator (c) of the secondary battery of the invention is typically
made from a polyolefin, preferably made from polyethylene or
polypropylene.
[0107] The secondary battery of the invention is typically filled with an electrolyte medium [medium (E)].
[0108] The medium (E) typically comprises a metal salt. The metal salt is typically selected from the group consisting of Mel, Me(PF6)n, Me(BF4)n, Me(CIO4)n, Me(bis(oxalato)borate)n ("Me(BOB)n"), MeCF3SO3, Me[N(CF3SO2)2]n,
Me[N(C2F5SO2)2]n, Me[N(CF3SO2)(RFSO2)]n with RF being C2F5, C4F9, CF3OCF2CF2, Me(AsF6)n, Me[C(CF3SO2)3]n, Me2Sn, wherein Me is a metal, preferably a transition metal, an alkaline metal or an alkaline-earth metal, more preferably Me being Li, Na, K, Cs, and n is the valence of said metal, typically n being 1 or 2.
[0109] The metal salt is preferably selected from the group consisting of Lil,
LiPF6, LiBF4, LiCIO4, lithium bis(oxalato)borate ("LiBOB"), UCF3SO3, LiN(CF3SO2)2, LiN(C2F5SO2)2, M[N(CF3SO2)(RFSO2)]n with RF being C2F5, C F9, CF3OCF2CF2, LiAsFe, LiC(CF3SO2)3, Li2Sn and combinations thereof.
[01 10] The medium (E) typically further comprises at least one organic solvent selected from the group consisting of alkyl carbonates, alkyl ethers, sulfones, ionic liquids, fluorinated alkyl carbonates and fluorinated alkyl ethers.
[01 1 1] According to an embodiment of the invention, the medium (E) may further comprise at least one polysulphide of formula Li2Sn, wherein n is equal to 1 or higher than 1 , preferably n being comprised between 1 and 12.
[01 12] The Applicant thinks, without this limiting the scope of the invention, that, during operation of a secondary battery in either charge cycles or discharge cycles, due to the presence in the electrolyte medium [medium (E)] of at least one polysulphide of formula Li2Sn, wherein n is equal to 1 or higher than 1 , preferably n being comprised between 1 and 12, a sulphur layer is advantageously deposited onto the positive electrode of said secondary battery, typically onto at least one carbon layer of the positive electrode of said secondary battery.
[01 13] Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.
[01 14] The invention will be now described in more detail with reference to the following examples whose purpose is merely illustrative and not limitative of the scope of the invention.
[01 15] Manufacture of polymer (F-1)
[01 16] (A) Manufacture of polymer precursor in -SO2F form.
In a 22 litre autoclave the following reagents were charged: 1 1.5 litre of demineralized water, 980 g of CF2=CF-O-CF2CF2-SO2F and 3100 g of a 5% by weight water solution of CF2CIO(CF2CF(CF3)O)n(CF2O)mCF2COOK (average molecular weight: 521 ; ratio n/m: 10).
The autoclave, stirred at 470 rpm, was heated to a temperature of 60°C and then 150 ml of a water solution containing 6 g/litre of potassium persulphate was added. The pressure was maintained at a value of 12 absolute bar by introducing tetrafluoroethylene (TFE).
After the addition of 1200 g of TFE in the reactor, 220 g of CF2=CF-O- CF2CF2-SO2F were added every 200 g of TFE fed to the autoclave. The stirring was stopped after 284 min, the autoclave was cooled and the internal pressure was reduced by venting the TFE: a total amount of 4000 g of TFE were fed.
A latex with a concentration of 28% by weight was obtained.
A portion of the latex was then coagulated by freezing and thawing and the recovered polymer was washed with water and dried for 40 hours at 150°
C.
The remaining amount of latex was kept under nitrogen bubbling for 16 hours to strip away residual monomers from the polymerization and then frozen in a plastic tank for 48 hours. After evaporation of the water, the coagulated polymer precursor was washed several times with
demineralized water and dried in oven at 80°C for 48 hours thereby obtaining a dry powder.
The polymer was then treated with a mixture of nitrogen and fluorine gas (50/50) in a Monel reactor at 80°C and ambient pressure for 10 hours with a gas flow of 5 Nl/hour, and then dried in a ventilated oven at 80°C for 24 hours.
The same procedure can be used to prepare polymer precursors in -SO2F form having different equivalent weights by varying the reactants feeding ratios.
[01 17] (B) Manufacture of polymer in -SO3U form
The polymer precursor in -SO2F form so obtained was treated for 10 hours
with a NaOH solution (10% by weight of NaOH, 10 litre of solution per Kg of polymer) at 80°C and then washed several times with demineralized water until the pH of the water was less than 9. The polymer was then treated with HNO3 (20% by weight) in order to obtain complete exchange to -SO3H form. The polymer was rinsed with water and dried in ventilated oven at 80°C for 20 hours.
An excess amount of U2CO3 was then added to the aqueous dispersion under stirring at ambient temperature in order to convert all the -SO3H groups into -SO3L1 form; evolution of CO2 bubbles was noticed. The polymer powder was then rinsed with water and dried in ventilated oven at 80°C for 20 hours.
[01 18] Determination of the equivalent weight of polymer (F-1)
A film was prepared from a sample of dry polymer obtained following procedure (A) as detailed hereinabove by heating the powder in a press at 270°C for 5 min. A film sample (10 cm x 10 cm) was cut and treated with a 10% by weight KOH solution in water for 24 hours at 80°C and then, after washing with pure water, with a 20% by weight HNO3 solution at ambient temperature. The film was finally washed with water. Using this procedure the functional groups of the polymer were converted from the -SO2F form to -SO3H form.
After drying in vacuum at 150°C, the film was titrated with a standard NaOH solution (e.g. NaOH 0.1 N).
[01 19] Example 1
A solution containing 5% by weight of polymer (F-1 ) having an equivalent weight of 660 g/eq in propylene carbonate was prepared after 4 hours under stirring at 80°C. The solution so obtained was clear and
homogeneous.
[0120] Example 2
A solution containing 10% by weight of polymer (F-1 ) having an equivalent weight of 870 g/eq in propylene carbonate was prepared after 4 hours under stirring at 80°C. The solution so obtained was clear and
homogeneous.
[0121] Comparative Example 1
The same procedure as detailed under Example 1 was followed but using dimethyl sulphoxide.
[0122] Comparative Example 2
The same procedure as detailed under Example 1 was followed but using N-methyl-2-pyrrolidone.
[0123] Example 3 - Manufacture of a film
A film having a thickness of 20 pm was manufactured using the solution prepared according to Example 1 by tape casting and drying (48 hours under vacuum at 120°C).
[0124] Example 4 - Manufacture of a negative electrode
A lithium electrode was prepared using a current collector comprising a lithium foil which was cut in the desired dimensions. The solution prepared according to Example 1 was then coated by doctor blade technique onto the lithium foil of the current collector and then dried at 60°C (firstly under argon, then under vacuum) thereby providing a protective layer having a final thickness of about 30 pm. The assembly so obtained was cut thereby providing a negative electrode comprising a lithium layer having a diameter of 14 mm and, adhered to said lithium layer, a protective film having a diameter of 16 mm.
[0125] Example 5 - Manufacture of a negative electrode
The film prepared according to Example 3 was dried under vacuum to remove water traces. Lithium metal deposition with thicknesses up to about 1 pm was performed on the film by vacuum evaporation technique. The lithium/protective film stack was then cut into a lithium electrode.
[0126] Comparative Example 3
The same procedure as detailed under Example 4 was followed but using the solution prepared according to Comparative Example 1.
[0127] Comparative Example 4
The same procedure as detailed under Example 4 was followed but using the solution prepared according to Comparative Example 2.
[0128] Manufacture of a sulphur positive electrode
A sulphur cathode was prepared by mixing carbon black powder (10% by
weight), sulphur powder (80% by weight) and a polyvinylidene fluoride binder (10% by weight) in N-methyl-2-pyrrolidone. The slurry was then coated onto an aluminium foil of 20 μηη to a thickness of 100 μηη. After drying at 55°C, the thickness of the electrode was about 15 μηη, with a loading of sulphur of about 1.8 mg/cm2.
[0129] Example 6 - Manufacture of a Li-S battery
A coin cell was assembled under controlled atmosphere in a glove box. The lithium electrode prepared according to Example 4 was cut into a 14 mm disk and then dried under vacuum. An assembly was prepared using a CR2032 coin cell casing, said assembly comprising, in succession, a sulphur positive electrode having a diameter of 14 mm, a porous separator made of polypropylene having a diameter of 16.5 mm and the negative electrode prepared according to Example 4. An electrolyte medium containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) 1 M in tetraethylene glycol dimethyl ether (TEGDME)/1 ,3-dioxolane (DIOX) (50/50 by volume) was impregnated into the cell so obtained. The cell was then sealed in the glove box and then cycled between 1.5 V and 3 V vs. Li+/Li at C/10.
[0130] Example 7 - Manufacture of a Li-S battery
A coin cell was assembled under controlled atmosphere in a glove box. The film prepared according to Example 3 was cut into a 16.5 mm disk and then dried under vacuum. An assembly was prepared using a CR2032 coin cell casing, said assembly comprising, in succession, a sulphur positive electrode having a diameter of 14 mm, a porous separator made of polypropylene having a diameter of 16.5 mm, the film prepared according to Example 3 having a diameter of 16.5 mm and a lithium electrode having a diameter of 16 mm. An electrolyte medium containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) 1 M in tetraethylene glycol dimethyl ether (TEGDME)/1 ,3-dioxolane (DIOX) (50/50 by volume) was impregnated into the cell so obtained. The cell was then sealed in the glove box and then cycled between 1.5 V and 3 V vs. Li+/Li at C/10.
[0131] Comparative Example 5
A mixture comprising 10.4% by weight of polymer (F-1 ) having an
equivalent weight of 790, 75.0% by weight of water and 14.6% by weight of n-propanol was prepared and subsequently dropped onto a circular sample of porous separator made of polypropylene (weight: 170 mg, area: 95 cm2, thickness: 30 μηη) at room temperature. The wet separator so obtained was then dried in an oven using the following temperature program: 1.5 hours at 65°C, 1.5 hours at 90°C and 15 minutes at 160°C. After drying, the weight increase and the SEM analysis confirmed the presence of a dense and homogeneous polymer film covering the pores initially present on the polypropylene support (0.25 mg/cm2 on each side). An assembly was prepared using a CR2032 coin cell casing, said assembly comprising, in succession, a sulphur positive electrode having a diameter of 14 mm, the separator so obtained having a diameter of 16.5 mm and a lithium electrode having a diameter of 16 mm. An electrolyte medium containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) 1 M in tetraethylene glycol dimethyl ether (TEGDME)/1 ,3-dioxolane (DIOX) (50/50 by volume) was impregnated into the cell so obtained. The cell was then sealed in the glove box and then cycled between 1.5 V and 3 V vs. Li+/Li at C/10.
[0132] Comparative Example 6
A coin cell was assembled under controlled atmosphere in a glove box. An assembly was prepared using a CR2032 coin cell casing, said assembly comprising, in succession, a sulphur positive electrode having a diameter of 14 mm, a porous separator made of polypropylene having a diameter of 16.5 mm and a lithium electrode having a diameter of 16 mm. An electrolyte medium containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) 1 M in tetraethylene glycol dimethyl ether (TEGDME)/1 ,3- dioxolane (DIOX) (50/50 by volume) was impregnated into the cell so obtained. The cell was then sealed in the glove box and then cycled between 1.5 V and 3 V vs. Li+/Li at C/10.
[0133] Comparative Example 7
A Li/S cell was prepared following the same procedure as detailed under Example 6 but using the lithium electrode prepared according to
Comparative Example 3.
[0134] Comparative Example 8
A Li/S cell was prepared following the same procedure as detailed under Example 6 but using the lithium electrode prepared according to
Comparative Example 4.
[0135] Electrochemical measurements
Electrochemical measurements were performed in CR2032 coin cells at room temperature and C/100 between 1.5V and 3V.
The results are set forth in Table 1 here below.
Data reported in Table 1 represent average values of two cell test measurements carried out in parallel.
The specific discharge capacity values [mAh/g of S] are representative of the percentage of sulphur utilization in the Li-S coin cells.
The capacity retention values [%] are representative of the retention of the initial specific discharge capacity values upon charge/discharge cycles of the Li-S coin cells. The higher the capacity retention values, the better the cycle life of the cell.
The columbic efficiency values [%] are representative of the fraction of the electrical charge stored during charging that is recoverable during discharge.
Table 1
Run Ex.7 C.Ex.5 C.Ex.6 C.Ex.7 C.Ex.8
Specific
Discharge
Cycle 1 1050 806 780 715 790 Capacity at C/100
[mAh/g]
Capacity Cycle 2 64 66 - - - retention at 20°C Cycle 25 51 - - - - and C/100 [%] Cycle 50 40 - - - -
Columbic Cycle 2 96 <50 - - - Efficiency at 20°C Cycle 25 88 - - - - and C/100 [%] Cycle 50 89 - - - -
[0136] The runs corresponding to the electrochemical measurements of the Li-S coin cells of Comparative Examples 6, 7 and 8 were stopped after the first cycle due to polysulphide shuttle mechanism. Also, the run corresponding to the electrochemical measurements of the Li-S coin cell of Comparative Example 5 was stopped after the second cycle due to polysulphide shuttle mechanism.
[0137] As shown by the charge/discharge curves of the Li-S coin cells of
Comparative Examples 5, 6, 7 and 8, an infinite charging threshold was registered leading to reduced columbic efficiency of the cell.
[0138] In contrast, good capacity retention and columbic efficiency (after at least up to 50 cycles) were observed during the electrochemical measurements of the Li-S batteries of the present invention as notably embodied by the Li-S coin cells of Examples 6 and 7 according to the invention. Without wishing to be bound by theory, this indicates an absent or very reduced polysulphide shuttle mechanism in the cells according to the invention.
[0139] Moreover, as shown in Table 1 here above, the Li-S coin cells of Example 7 according to the invention successfully exhibited both higher specific discharge capacity values and higher columbic efficiency values as compared to conventional Li-S batteries as notably embodied by any of the Li-S coin cells of Comparative Examples 5, 6, 7 and 8.
[0140] Further, as shown in Table 1 here above, the Li-S coin cells of Example 7 according to the invention successfully exhibited good or higher capacity retention values as compared to conventional Li-S batteries as notably embodied by the Li-S coin cell of Comparative Example 5.
[0141] In view of all the above, it has been thus found that the Li-S battery of the invention successfully exhibited absent or reduced polysulphide shuttle mechanism, while maintaining good or increased capacity values, as compared to conventional Li-S batteries.
Claims
Claims
A process for manufacturing a film, said process comprising:
(i) providing a composition [composition (C)] comprising, preferably consisting of:
- at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)] and
- a liquid medium [medium (L)] comprising at least 50% by weight, based on the total weight of said medium (L), of at least one alkyl carbonate;
(ii) processing the composition (C) provided in step (i) into a film; and
(iii) drying the film provided in step (ii).
The process according to claim 1 , wherein the composition (C) is in the form of a solution.
The process according to claim 1 or 2, wherein the polymer (F) comprises recurring units deriving from:
- at least one monomer (FM) selected from the group consisting of
fluorovinylethers of formula CF2=CF-O-(CF2)m-SO3Li, wherein m is an integer comprised between 1 and 6, preferably between 2 and 4, and
- tetrafluoroethylene.
The process according to any one of claims 1 to 3, wherein the alkyl carbonate is selected from the group consisting of linear alkyl carbonates of formula (I) and cyclic alkylene carbonates of formula (II):
wherein:
Ra and Rb, equal to or different from each other, are independently C1-C6 alkyl groups, preferably Ci-C4 alkyl groups, more preferably C1-C2 alkyl groups, and
Rc is a hydrogen atom or a C1-C6 alkyl group, preferably a hydrogen atom or a Ci-C4 alkyl group, more preferably a hydrogen atom or a C1-C2 alkyl group.
5. The process according to any one of claims 1 to 4, wherein the medium (L) further comprises at least one alkyl ether.
6. A film obtainable by the process according to any one of claims 1 to 5.
7. The film according to claim 6, said film comprising, preferably consisting of, at least one layer comprising at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a - SO3M functional group, wherein M is an alkaline metal [monomer (FM)].
8. An electrode comprising a current collector, said current collector comprising:
- at least one lithium layer, and
- adhered to said at least one lithium layer, the film according to claim 6 or 7.
9. A process for manufacturing the electrode according to claim 8, said process comprising:
(i-1 ) providing a current collector comprising at least one lithium layer;
(ii-1 ) providing a composition [composition (C)] comprising, preferably consisting of:
- at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)] and
- a liquid medium [medium (L)] comprising at least 50% by weight, based on the total weight of said medium (L), of at least one alkyl carbonate;
(iii-1 ) applying the composition (C) provided in step (ii-1 ) onto the at least one lithium layer of the current collector provided in step (i-1 ) thereby providing a film; and
(iv-1 ) drying the film provided in step (iii-1 ).
10. A process for manufacturing the electrode according to claim 8, said process comprising:
(i-2) providing a current collector comprising at least one lithium layer;
(ii-2) providing a film, said film being obtainable by a process comprising: (i) providing a composition [composition (C)] comprising, preferably consisting of:
- at least one fluoropolymer [polymer (F)] comprising recurring units derived
from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)] and
- a liquid medium [medium (L)] comprising at least 50% by weight, based on the total weight of said medium (L), of at least one alkyl carbonate;
(ii) processing the composition (C) provided in step (i) into a film; and
(iii) drying the film provided in step (ii); and
(iii-2) applying the film provided in step (ii-2) onto the at least one lithium layer of the current collector provided in step (i-2).
1 1. A process for manufacturing the electrode according to claim 8, said process comprising:
(i-3) providing a film, said film being obtainable by a process comprising:
(i) providing a composition [composition (C)] comprising, preferably consisting of:
- at least one fluoropolymer [polymer (F)] comprising recurring units derived from at least one fluorinated monomer comprising a -SO3M functional group, wherein M is an alkaline metal [monomer (FM)] and
- a liquid medium [medium (L)] comprising at least 50% by weight, based on the total weight of said medium (L), of at least one alkyl carbonate;
(ii) processing the composition (C) provided in step (i) into a film; and
(iii) drying the film provided in step (ii),
said film having an inner surface and an outer surface;
(ii-3) depositing at least one lithium layer onto the film provided in step (i-3); and
(iii-3) optionally, applying at least one metal layer onto the at least one lithium layer provided in step (ii-3).
12. A secondary battery comprising:
(a) an electrode comprising a current collector, said current collector comprising:
- at least one lithium layer, and
- adhered to said at least one lithium layer, the film according to claim 6 or 7,
(b) a positive electrode, and
(c) a separator.
13. The secondary battery according to clainn 12, wherein the separator (c) is adhered between the film of the electrode (a) and the positive electrode (b).
14. The secondary battery according to claim 12 or 13, said secondary battery being a lithium-sulphur (Li-S) battery wherein the positive electrode (b) comprises a current collector, said current collector comprising at least one sulphur layer.
15. The Li-S battery according to claim 14, wherein the positive electrode (b) comprises a current collector, said current collector comprising:
- at least one carbon layer, and
- adhered to said at least one carbon layer, at least one sulphur layer.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020177017043A KR20170086097A (en) | 2014-11-25 | 2015-11-20 | Lithium electrodes for lithium-sulphur batteries |
| EP15797681.2A EP3224879A1 (en) | 2014-11-25 | 2015-11-20 | Lithium electrodes for lithium-sulphur batteries |
| US15/529,830 US20170263919A1 (en) | 2014-11-25 | 2015-11-20 | Lithium electrodes for lithium-sulphur batteries |
| JP2017527706A JP6644783B2 (en) | 2014-11-25 | 2015-11-20 | Lithium electrode for lithium-sulfur battery |
| CN201580064322.5A CN107004839A (en) | 2014-11-25 | 2015-11-20 | Lithium electrode for lithium-sulfur cell |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP14306878 | 2014-11-25 | ||
| EP14306878.1 | 2014-11-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2016083271A1 true WO2016083271A1 (en) | 2016-06-02 |
Family
ID=52134077
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2015/077288 WO2016083271A1 (en) | 2014-11-25 | 2015-11-20 | Lithium electrodes for lithium-sulphur batteries |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US20170263919A1 (en) |
| EP (1) | EP3224879A1 (en) |
| JP (1) | JP6644783B2 (en) |
| KR (1) | KR20170086097A (en) |
| CN (1) | CN107004839A (en) |
| WO (1) | WO2016083271A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018054715A1 (en) | 2016-09-22 | 2018-03-29 | Solvay Specialty Polymers Italy S.P.A. | Compositions for coating of active metals |
| EP3745505A1 (en) | 2019-05-30 | 2020-12-02 | Acondicionamiento Tarrasense | Functionalized lithium anode for batteries |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102663582B1 (en) * | 2018-09-28 | 2024-05-03 | 주식회사 엘지에너지솔루션 | Lithium polysulfide analyzing apparatus and method for lithium-sulfur secondary battery |
| CN110556509A (en) * | 2019-08-14 | 2019-12-10 | 南京大学 | Method for performing surface protection and passivation treatment on metallic lithium cathode by using fluorine-containing organic matter, product and application |
| KR102367177B1 (en) * | 2021-08-19 | 2022-02-25 | 주식회사 수산 | Binder Composition Comprising Aqueous Polyurethane Dispersion, Electrode Comprising Same, and Lithium Secondary Battery Comprising the Electrode |
| WO2024033090A1 (en) * | 2022-08-10 | 2024-02-15 | Solvay Specialty Polymers Italy S.P.A. | Binder solution for a secondary battery |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1416573A2 (en) * | 2002-10-25 | 2004-05-06 | Samsung SDI Co., Ltd. | Negative electrode for lithium secondary battery and lithium secondary battery comprising same |
| JP2011159503A (en) * | 2010-02-01 | 2011-08-18 | Daikin Industries Ltd | Lithium ion conductive polymer electrolyte and lithium battery |
| JP2014210929A (en) * | 2010-02-01 | 2014-11-13 | ダイキン工業株式会社 | Method for producing fluorine-containing copolymer, polymer electrolyte, electrode for lithium battery, and lithium battery |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6025092A (en) * | 1998-02-13 | 2000-02-15 | E. I. Du Pont De Nemours And Company | Fluorinated ionomers and their uses |
| DE69904919T2 (en) * | 1998-03-03 | 2003-11-13 | E.I. Du Pont De Nemours And Co., Wilmington | ESSENTIAL FLUORINE IONOMERS |
| US6777515B2 (en) * | 2001-07-13 | 2004-08-17 | I. Du Pont De Nemours And Company | Functional fluorine-containing polymers and ionomers derived therefrom |
| US20130181677A1 (en) * | 2012-01-18 | 2013-07-18 | E I Du Pont De Nemours And Company | Compositions, layerings, electrodes and methods for making |
-
2015
- 2015-11-20 US US15/529,830 patent/US20170263919A1/en not_active Abandoned
- 2015-11-20 JP JP2017527706A patent/JP6644783B2/en active Active
- 2015-11-20 WO PCT/EP2015/077288 patent/WO2016083271A1/en active Application Filing
- 2015-11-20 CN CN201580064322.5A patent/CN107004839A/en active Pending
- 2015-11-20 EP EP15797681.2A patent/EP3224879A1/en active Pending
- 2015-11-20 KR KR1020177017043A patent/KR20170086097A/en unknown
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1416573A2 (en) * | 2002-10-25 | 2004-05-06 | Samsung SDI Co., Ltd. | Negative electrode for lithium secondary battery and lithium secondary battery comprising same |
| JP2011159503A (en) * | 2010-02-01 | 2011-08-18 | Daikin Industries Ltd | Lithium ion conductive polymer electrolyte and lithium battery |
| JP2014210929A (en) * | 2010-02-01 | 2014-11-13 | ダイキン工業株式会社 | Method for producing fluorine-containing copolymer, polymer electrolyte, electrode for lithium battery, and lithium battery |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018054715A1 (en) | 2016-09-22 | 2018-03-29 | Solvay Specialty Polymers Italy S.P.A. | Compositions for coating of active metals |
| CN109792043A (en) * | 2016-09-22 | 2019-05-21 | 索尔维特殊聚合物意大利有限公司 | For coating the composition of active metal |
| JP2019530167A (en) * | 2016-09-22 | 2019-10-17 | ソルベイ スペシャルティ ポリマーズ イタリー エス．ピー．エー． | Composition for coating active metals |
| EP3745505A1 (en) | 2019-05-30 | 2020-12-02 | Acondicionamiento Tarrasense | Functionalized lithium anode for batteries |
| WO2020240308A1 (en) | 2019-05-30 | 2020-12-03 | Acondicionamiento Tarrasense | Functionalized lithium anode for batteries |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20170086097A (en) | 2017-07-25 |
| EP3224879A1 (en) | 2017-10-04 |
| US20170263919A1 (en) | 2017-09-14 |
| JP2018503212A (en) | 2018-02-01 |
| JP6644783B2 (en) | 2020-02-12 |
| CN107004839A (en) | 2017-08-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10128481B2 (en) | Lithium-based battery separator and method for making the same | |
| JP6644783B2 (en) | Lithium electrode for lithium-sulfur battery | |
| KR100996556B1 (en) | Nonaqueous electrolyte secondary battery | |
| KR101607024B1 (en) | Lithium secondary battery | |
| US9525197B2 (en) | Stable non-aqueous electrolyte promoting ideal reaction process in rechargeable lithium-air batteries | |
| KR20140125970A (en) | Lithium metal battery and method of preparing the same | |
| CN101371396B (en) | Nonaqueous electrolyte secondary battery | |
| KR102292727B1 (en) | Lithium metal secondary battery with improved safety and including the same | |
| KR102126278B1 (en) | Lithium air battery | |
| CN112490498B (en) | Lithium ion conductive composition for all-solid-state lithium battery, solid polymer electrolyte and all-solid-state lithium battery | |
| JP5702901B2 (en) | Lithium secondary battery and non-aqueous electrolyte for lithium secondary battery | |
| KR20180089244A (en) | Lithium secondary battery comprising the electrolyte containing monofluorosilane compound | |
| KR20140048153A (en) | Lithium/sulphur accumulator | |
| JP2019053984A (en) | Additive agent for nonaqueous electrolyte solution, nonaqueous electrolyte solution, and nonaqueous electrolyte battery | |
| KR101671583B1 (en) | High energy density lithium-sulfur battery having interlayer containing active materials | |
| JP2019053983A (en) | Non-aqueous electrolyte additive, electrolyte for non-aqueous electrolyte cell, and non-aqueous electrolyte cell | |
| KR20130120250A (en) | Negative electrode for rechargeable lithium battery, method of preparing the same, and rechargeable lithium battery including the same | |
| KR20150133343A (en) | Positive electrode for lithium sulfur battery and lithium sulfur battery including the same | |
| WO2018070735A2 (en) | Anode for lithium secondary battery and lithium secondary battery comprising same | |
| JP2006073221A (en) | Separator for lithium ion secondary battery, and lithium ion secondary battery | |
| CN110100331B (en) | Anode, method for manufacturing the same, and lithium ion secondary battery | |
| KR20150109241A (en) | Lithium sulfur battery | |
| KR101173868B1 (en) | Positive active material for rechargeable lithium battery and rechargeable lithium battery | |
| KR101613766B1 (en) | Gel polymer electrolyte and secondary battery comprising the same | |
| KR102003306B1 (en) | Lithium electrode and lithium battery compring the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 15797681 Country of ref document: EP Kind code of ref document: A1 |
|
| REEP | Request for entry into the european phase |
Ref document number: 2015797681 Country of ref document: EP |
|
| ENP | Entry into the national phase |
Ref document number: 2017527706 Country of ref document: JP Kind code of ref document: A |
|
| WWE | Wipo information: entry into national phase |
Ref document number: 15529830 Country of ref document: US |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| ENP | Entry into the national phase |
Ref document number: 20177017043 Country of ref document: KR Kind code of ref document: A |