EP4264722A1 - All-solid-state lithium-sulphur electrochemical element - Google Patents
All-solid-state lithium-sulphur electrochemical elementInfo
- Publication number
- EP4264722A1 EP4264722A1 EP21823307.0A EP21823307A EP4264722A1 EP 4264722 A1 EP4264722 A1 EP 4264722A1 EP 21823307 A EP21823307 A EP 21823307A EP 4264722 A1 EP4264722 A1 EP 4264722A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- cathode
- copper
- solid electrolyte
- lithium
- anode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- JDZCKJOXGCMJGS-UHFFFAOYSA-N [Li].[S] Chemical compound [Li].[S] JDZCKJOXGCMJGS-UHFFFAOYSA-N 0.000 title claims abstract description 13
- 239000010949 copper Substances 0.000 claims abstract description 97
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 95
- 229910052802 copper Inorganic materials 0.000 claims abstract description 92
- 239000007784 solid electrolyte Substances 0.000 claims abstract description 73
- 239000000203 mixture Substances 0.000 claims abstract description 68
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 55
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 45
- 239000011149 active material Substances 0.000 claims abstract description 38
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 37
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 19
- 239000000956 alloy Substances 0.000 claims abstract description 19
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 17
- 239000006182 cathode active material Substances 0.000 claims abstract description 6
- 150000001875 compounds Chemical class 0.000 claims description 41
- 239000000843 powder Substances 0.000 claims description 27
- 239000007787 solid Substances 0.000 claims description 23
- 229910001216 Li2S Inorganic materials 0.000 claims description 19
- 229910052751 metal Inorganic materials 0.000 claims description 17
- 239000002184 metal Substances 0.000 claims description 17
- 125000005843 halogen group Chemical group 0.000 claims description 12
- 239000002243 precursor Substances 0.000 claims description 12
- 229910052801 chlorine Inorganic materials 0.000 claims description 11
- 229910052740 iodine Inorganic materials 0.000 claims description 11
- 229910052794 bromium Inorganic materials 0.000 claims description 10
- 229910000733 Li alloy Inorganic materials 0.000 claims description 7
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 7
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical class [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 claims description 6
- 239000011248 coating agent Substances 0.000 claims description 5
- 238000000576 coating method Methods 0.000 claims description 5
- 229910052731 fluorine Inorganic materials 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 5
- 229910052738 indium Inorganic materials 0.000 claims description 5
- 229910052729 chemical element Inorganic materials 0.000 claims description 3
- 229910052736 halogen Inorganic materials 0.000 claims description 3
- 229910000921 lithium phosphorous sulfides (LPS) Inorganic materials 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- 239000006104 solid solution Substances 0.000 claims description 3
- 150000003464 sulfur compounds Chemical class 0.000 claims description 3
- 229910052718 tin Inorganic materials 0.000 claims description 3
- FUJCRWPEOMXPAD-UHFFFAOYSA-N Li2O Inorganic materials [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 claims description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 2
- XUCJHNOBJLKZNU-UHFFFAOYSA-M dilithium;hydroxide Chemical compound [Li+].[Li+].[OH-] XUCJHNOBJLKZNU-UHFFFAOYSA-M 0.000 claims description 2
- 239000010703 silicon Substances 0.000 claims description 2
- QUQFTIVBFKLPCL-UHFFFAOYSA-L copper;2-amino-3-[(2-amino-2-carboxylatoethyl)disulfanyl]propanoate Chemical compound [Cu+2].[O-]C(=O)C(N)CSSCC(N)C([O-])=O QUQFTIVBFKLPCL-UHFFFAOYSA-L 0.000 claims 1
- 239000005864 Sulphur Substances 0.000 abstract description 2
- 229910052717 sulfur Inorganic materials 0.000 description 37
- 239000011593 sulfur Substances 0.000 description 37
- 239000002131 composite material Substances 0.000 description 25
- 230000000052 comparative effect Effects 0.000 description 21
- 210000004027 cell Anatomy 0.000 description 11
- 230000006835 compression Effects 0.000 description 11
- 238000007906 compression Methods 0.000 description 11
- 239000003792 electrolyte Substances 0.000 description 10
- 229920001021 polysulfide Polymers 0.000 description 10
- 239000011244 liquid electrolyte Substances 0.000 description 9
- 239000011230 binding agent Substances 0.000 description 8
- 229910052782 aluminium Inorganic materials 0.000 description 7
- 239000000470 constituent Substances 0.000 description 7
- 239000011148 porous material Substances 0.000 description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- -1 copper sulphide-sulphur-carbon composites Chemical class 0.000 description 6
- 238000007599 discharging Methods 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 239000011532 electronic conductor Substances 0.000 description 5
- GNFTZDOKVXKIBK-UHFFFAOYSA-N 3-(2-methoxyethoxy)benzohydrazide Chemical compound COCCOC1=CC=CC(C(=O)NN)=C1 GNFTZDOKVXKIBK-UHFFFAOYSA-N 0.000 description 4
- FGUUSXIOTUKUDN-IBGZPJMESA-N C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 Chemical compound C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 FGUUSXIOTUKUDN-IBGZPJMESA-N 0.000 description 4
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 4
- 239000006229 carbon black Substances 0.000 description 4
- 230000001351 cycling effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000000227 grinding Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000008188 pellet Substances 0.000 description 4
- 239000005077 polysulfide Substances 0.000 description 4
- 150000008117 polysulfides Polymers 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 210000001787 dendrite Anatomy 0.000 description 3
- 229920001971 elastomer Polymers 0.000 description 3
- 239000000806 elastomer Substances 0.000 description 3
- 230000003993 interaction Effects 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 239000001989 lithium alloy Substances 0.000 description 3
- 229910001416 lithium ion Inorganic materials 0.000 description 3
- YQCIWBXEVYWRCW-UHFFFAOYSA-N methane;sulfane Chemical compound C.S YQCIWBXEVYWRCW-UHFFFAOYSA-N 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 229910000846 In alloy Inorganic materials 0.000 description 2
- 229910018091 Li 2 S Inorganic materials 0.000 description 2
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 2
- 229920000459 Nitrile rubber Polymers 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 2
- 239000002174 Styrene-butadiene Substances 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- GJEAMHAFPYZYDE-UHFFFAOYSA-N [C].[S] Chemical compound [C].[S] GJEAMHAFPYZYDE-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- NTXGQCSETZTARF-UHFFFAOYSA-N buta-1,3-diene;prop-2-enenitrile Chemical compound C=CC=C.C=CC#N NTXGQCSETZTARF-UHFFFAOYSA-N 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 150000001879 copper Chemical class 0.000 description 2
- JLQNHALFVCURHW-UHFFFAOYSA-N cyclooctasulfur Chemical compound S1SSSSSSS1 JLQNHALFVCURHW-UHFFFAOYSA-N 0.000 description 2
- 150000002170 ethers Chemical class 0.000 description 2
- 150000002367 halogens Chemical group 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- AMXOYNBUYSYVKV-UHFFFAOYSA-M lithium bromide Chemical compound [Li+].[Br-] AMXOYNBUYSYVKV-UHFFFAOYSA-M 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229920002239 polyacrylonitrile Polymers 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 230000002441 reversible effect Effects 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 229920003048 styrene butadiene rubber Polymers 0.000 description 2
- WNXJIVFYUVYPPR-UHFFFAOYSA-N 1,3-dioxolane Chemical compound C1COCO1 WNXJIVFYUVYPPR-UHFFFAOYSA-N 0.000 description 1
- MEKOFIRRDATTAG-UHFFFAOYSA-N 2,2,5,8-tetramethyl-3,4-dihydrochromen-6-ol Chemical compound C1CC(C)(C)OC2=C1C(C)=C(O)C=C2C MEKOFIRRDATTAG-UHFFFAOYSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- JAHNSTQSQJOJLO-UHFFFAOYSA-N 2-(3-fluorophenyl)-1h-imidazole Chemical compound FC1=CC=CC(C=2NC=CN=2)=C1 JAHNSTQSQJOJLO-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- 101100461812 Arabidopsis thaliana NUP96 gene Proteins 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- SOGAXMICEFXMKE-UHFFFAOYSA-N Butylmethacrylate Chemical compound CCCCOC(=O)C(C)=C SOGAXMICEFXMKE-UHFFFAOYSA-N 0.000 description 1
- 229910018068 Li 2 O Inorganic materials 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229920002614 Polyether block amide Polymers 0.000 description 1
- 229910003092 TiS2 Inorganic materials 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- MTAZNLWOLGHBHU-UHFFFAOYSA-N butadiene-styrene rubber Chemical compound C=CC=C.C=CC1=CC=CC=C1 MTAZNLWOLGHBHU-UHFFFAOYSA-N 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 150000004678 hydrides Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- PEXNRZDEKZDXPZ-UHFFFAOYSA-N lithium selenidolithium Chemical compound [Li][Se][Li] PEXNRZDEKZDXPZ-UHFFFAOYSA-N 0.000 description 1
- GLNWILHOFOBOFD-UHFFFAOYSA-N lithium sulfide Chemical compound [Li+].[Li+].[S-2] GLNWILHOFOBOFD-UHFFFAOYSA-N 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 229910052960 marcasite Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000000133 mechanosynthesis reaction Methods 0.000 description 1
- LVHBHZANLOWSRM-UHFFFAOYSA-N methylenebutanedioic acid Natural products OC(=O)CC(=C)C(O)=O LVHBHZANLOWSRM-UHFFFAOYSA-N 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- NIFIFKQPDTWWGU-UHFFFAOYSA-N pyrite Chemical compound [Fe+2].[S-][S-] NIFIFKQPDTWWGU-UHFFFAOYSA-N 0.000 description 1
- 229910052683 pyrite Inorganic materials 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 230000007928 solubilization Effects 0.000 description 1
- 238000005063 solubilization Methods 0.000 description 1
- 239000011232 storage material Substances 0.000 description 1
- 239000011115 styrene butadiene Substances 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Classifications
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- 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
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
- H01M10/0562—Solid materials
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- 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
- H01M4/364—Composites as mixtures
-
- 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
- H01M4/38—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
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- 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
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
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- 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
- H01M4/624—Electric conductive fillers
- H01M4/626—Metals
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- 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
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- 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
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
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- 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
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/028—Positive electrodes
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0065—Solid electrolytes
- H01M2300/0068—Solid electrolytes inorganic
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0065—Solid electrolytes
- H01M2300/0068—Solid electrolytes inorganic
- H01M2300/008—Halides
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- 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
Definitions
- the technical field of the invention is that of all-solid lithium-sulphur electrochemical elements as well as that of methods for assembling such elements.
- Lithium/sulfur (Li/S) electrochemical elements comprising a liquid electrolyte are known from the state of the art. They typically comprise at least one positive electrode (cathode) of elemental sulfur, an organic liquid electrolyte and at least one negative electrode (anode) of lithium metal or lithium metal alloy.
- the cathode is usually composite, i.e. it is prepared from elemental sulfur and non-electrochemically active additives.
- Non-electrochemically active additives mention may be made of an electronic conductor, such as carbon, making it possible to improve the electronic conductivity of the cathode because sulfur is an electronic insulator. Mention may also be made of one or more polymeric binders making it possible to ensure cohesion between the different materials of the cathode. Due to the low atomic mass of lithium and the moderate mass of sulfur, Li/S electrochemical elements are relatively light. They are a promising alternative to lithium-ion cells due to their higher energy density and low sulfur cost.
- the electrochemical element is initially in the charged state.
- the elemental sulfur of the cathode is reduced to lithium sulphide Li2S and the metallic lithium or the metallic lithium alloy is oxidized at the anode.
- the following reactions take place at the electrodes:
- a lithium/sulfur electrochemical cell typically comprises an electrolyte whose solvent is based on ethers.
- Ethers such as 1,3-dioxolane or tetrahydrofuran have been used for several decades and allow significant solubilization of lithium polysulphides.
- DME 1,2-dimethoxyethane
- the cyclic molecules of sulfur (in the form of octasulfur Ss) are reduced and form linear chains of lithium polysulphides, of general formula Li2S n , n generally ranging from 2 to 8.
- the first compounds formed during the discharge of the element are the long-chain lithium polysulphides, such as Li2Ss or Li2Se.
- Long-chain lithium polysulfides are likely to migrate through the electrolyte and reach the lithium anode where they will be reduced to short-chain polysulfides during charging following cell discharge.
- the short-chain polysulfides return to the cathode where they are again reoxidized to long-chain polysulfides, and so on.
- This shuttle mechanism (“shuttle”) of the polysulphides between the anode and the cathode is the cause of a low coulombic efficiency of the element, that is to say a low ratio between the capacity discharged by the element and the capacitance charged in the element during the charge preceding the discharge. In addition, it leads to a high self-discharge, as well as a deterioration in the life of the element in cycling.
- liquid electrolyte of an Li/S electrochemical element can, in the event of thermal runaway of the element, react exothermically with the active materials of the negative and positive electrodes and in certain cases, the elements can catch fire, posing a safety risk to the user.
- the composite layer of the cathode comprising a mixture of the following three compounds:
- this element has a good capacity in charge and in discharge, that it is crossed as well by a low intensity current (for example from 0.5 to 1 mA/cm 2 ) as by a high intensity current (for example more than 5 mA/cm 2 ).
- Document JP 6716324 describes an all-solid lithium-sulfur electrochemical element comprising: a) a cathode comprising an electrode active material containing a sulfur-carbon composite and a metal such as copper; b) an anode whose active material is lithium; c) a solid hydride electrolyte such as LiBbL.
- the cathode sulfur, carbon and metal are mixed to obtain a mixture in which the metal is uniformly dispersed in the sulfur-carbon composite.
- the cathode can also contain LiBEL in a mass equal to the mass of the mixture.
- the amount of copper used is small. It corresponds to an nCu/nLi ratio of 0.00245 where nCu denotes the number of moles of copper and nLi denotes the sum of the numbers of moles of lithium in the solid electrolyte of the cathode and in the solid electrolyte inserted between the cathode and the anode. At such a low copper concentration, the improvement in the volumetric capacity of the element is not significant.
- Li/S element comprising a solid electrolyte
- a Li/S cell with a capacity of at least 2000 mAh, preferably at least 2500 mAh, per gram of sulfur for discharge at room temperature.
- a Li/S element comprising a solid electrolyte with a low drop in capacity during cycling operation.
- the invention provides an all-solid lithium-sulfur electrochemical element comprising: a) at least one cathode comprising a composition of cathodic active material comprising; i) elemental sulphur, ii) carbon, iii) a solid electrolyte, the cathode comprising copper, b) at least one anode whose active material is lithium or a lithium-based alloy, c) a solid electrolyte intercalated between said at least one cathode and said at least one anode, identical to or different from the solid electrolyte present in the cathodic active material composition, the amount of copper in the cathode being less than or equal to 0.37 g per ampere hour charged by the element, the nCu/nLi ratio in the element in the charged state being greater than or equal to 0.04 and less than 0.81 where nCu denotes the number of moles of copper and nLi denotes the sum of the numbers mole of lithium in the solid electrochemical element
- the copper is present in one or more of the following forms a, P and y: a) in the form of a metal collector serving as a current collector of the cathode, the metal collector being made of copper or a copper-based alloy or being made of a metal at least partially covered with a coating of copper or a copper-based alloy,
- the solid electrolyte of the cathodic active material composition and/or the solid electrolyte interposed between said at least one cathode and said at least one anode is a sulfur compound.
- the quantity of copper present in the cathode is less than or equal to 0.12 g per ampere hour charged by the element, preferably equal to 0.06 ⁇ 0.03 g per ampere hour. .
- the nCu/nLi ratio is less than 0.5, preferably less than 0.3.
- the solid electrolyte used in the cathode or interposed between the anode and the cathode during assembly of the element is in the form of a powder, the powder being covered with copper or of a compound containing copper.
- the solid electrolyte of the cathodic active material composition and the solid electrolyte interposed between said at least one cathode and said at least one anode are chosen from the group consisting of:
- an argyrodite compound optionally substituted by borohydride having the formula Li 7 -xPS6-xX x .z(BH 4 )z in which X is chosen from the group consisting of Cl, Br, I, F and CN; 0 ⁇ x ⁇ 2 and 0 ⁇ z ⁇ 0.50, and
- X designates one or more halogen atoms from Cl, Br and I after heat treatment of the mixture.
- the solid electrolyte is chosen from LiePSsI, LiePSsCl, LiePS5lo,9o(BH4)o,io, LiePS5lo,83(BH4)o,i7, Li6PSsIo,67(BH4)o,33, LiePS5lo,5o(BH4)o,5o and LiePS5Clo,83(BH4)o,i7.
- the solid electrolyte of the cathodic active material composition has the formula Li x PS y where 1.4 ⁇ x ⁇ 1.6 and 3 ⁇ y ⁇ 3.5 and the solid electrolyte inserted between said at least one cathode and said at least one anode is chosen from:
- Li7-xPS6-xXx-z(BH4) z wherein X is selected from the group consisting of Cl, Br, I, F and CN; 0 ⁇ x ⁇ 2 and 0 ⁇ z ⁇ 0.50, and
- Li2S/P2S/LiCl/LiBr/LiX compounds denotes one or more halogen atoms from Cl, Br and I followed by heat treatment of the mixture.
- the solid electrolyte interposed between said at least one cathode and said at least one anode has the formula LiePSsL/e BFLji/e.
- the alloy is an alloy of lithium and one or more chemical elements chosen from the group consisting of indium, silicon, tin and carbon.
- FIG. 1 is a schematic sectional view of the lithium-sulfur element according to the invention.
- FIG. 2 represents the charge and discharge curves of the comparative element 1 and of the element 1 according to the invention. Charging and discharging were carried out at room temperature at a charging rate of C/50 and D/50.
- FIG. 3 represents the variation in discharge capacity per gram of sulfur during cycling of element 1 according to the invention at room temperature.
- the charge phases are carried out at a rate of C/10 up to a voltage of 2.3 V.
- the discharge phases are carried out at a discharge rate of D/5 up to a stop voltage.
- FIG. 4 represents the charge and discharge curves of comparative element 2 and of element 2 outside the invention over two cycles. Charge at C/50 rate and discharge at D/50 rate.
- FIG. 5 represents the charging and discharging voltage curves of the comparative element 3 and of the element 3 according to the invention as a function of the discharged capacity (mAh). Charge at C/20 rate and discharge at D/20 rate.
- FIG. 6 represents the charging and discharging voltage curves of the element 3 according to the invention at cycles 3, 4, 5 and 6 as a function of the capacitance of the element per gram of sulfur in the composite SC. Charge at C/20 rate and discharge at D/20 rate.
- FIG. 7 represents the charge and discharge voltage curves of element 3 compared to cycles 1 and 8 as a function of the capacity of the element per gram of sulfur in the S-C composite. Charge at C/20 rate and discharge at D/20 rate.
- the invention is based on the discovery of the existence of an interaction between copper and the constituents of the cathode. This interaction leads to an increase in the electrochemical capacity of the element.
- the amount of copper in the cathode must be less than or equal to 0.37 g per ampere hour charged by the element.
- the nCu/nLi ratio in the element in the charged state must be greater than or equal to 0.04 and less than 0.81 where nCu denotes the number of moles of copper and nLi denotes the sum of the numbers of moles of lithium in the solid electrolyte of the cathode and in the solid electrolyte interposed between said at least one cathode and said at least one anode.
- the nCu/nLi ratio in the cell in the charged state may be greater than or equal to 0.09 or greater than or equal to 0.11 or greater than or equal to 0.29 or greater than or equal to 0.40 or greater or equal to 0.50 or greater than or equal to 0.70. It can be less than or equal to 0.09 or less than or equal to 0.11 or less than or equal to 0.29 or less than or equal to 0.40 or less than or equal to 0.50 or less than or equal to 0.70 .
- the introduction of copper can be done in one or more of these three ways.
- the structure of the element according to the invention is represented schematically in FIG. 1.
- the element comprises a cathode (1), an anode (2) and a solid electrolyte (3) inserted between the anode and the cathode.
- Figure 1 shows a single stack of a cathode, a layer of solid electrolyte acting as a separator and an anode.
- the electrochemical bundle may consist of several stacks.
- the cathode (1) comprises a current collector (4) preferably in the form of a copper strip or a strip of a copper-based alloy.
- the strap can be solid or perforated.
- the current collector can also be a metal strip covered on at least one of its faces with a copper or copper-based alloy coating.
- the current collector can also be a copper foam, an expanded copper or a copper felt.
- the current collector can be a solid or perforated strip made of a metal other than copper, for example aluminum, and copper is brought to the cathode either in the form of a copper powder incorporated into the composition of cathodic active material, or in the form of a chemical compound containing copper.
- the cathodic active material composition deposited on at least one of the faces of the current collector comprises the following constituents:
- Elemental solid sulfur exists in different molecular forms.
- the preferred form is sulfur alpha Sa, of formula Sx corresponding to cyclooctasulfur, which is the thermodynamically most stable form.
- the cathode does not contain transition metal sulfides such as TiS2, TiSs, TiS4, NiS, N1S2, CuS, FeS2, and MOS3. According to one embodiment, it does not contain Li2S when mounting the element.
- the cathode contains no other electrochemically active species than elemental sulfur and copper introduced in the forms presented above.
- the carbon used in the composite has a porous structure. It can have mesoporosity, i.e. pores having an average diameter greater than 2 nm and less than 50 nm or have microporosity, i.e. pores having an average diameter less than 2 nm .
- the average pore diameter can be between 0.5 and 2 nm.
- the pores of the porous structure house the elemental sulfur particles.
- the solid electrolyte (7) of the cathode is an ionically conductive compound, mainly conductive of Lit II ions is preferably an inorganic sulfur compound which can be chosen from:
- a preferred compound is Lii ; 5PS3.3.
- a typical precursor composition comprises 60 mole % Li2S and 40 mole % P2S5;
- LiePSsX of argyrodite type where X denotes a halogen atom, capable of being obtained from the precursors Li2S, P2S5 and LiX, for example LiePSsI or Li 6 PS 5 Cl;
- X is chosen from the group consisting of Cl, Br, I, F and CN; 0 ⁇ x ⁇ 2 and 0 ⁇ z ⁇ 0.50.
- x can be equal to 1.
- X is preferably I or Cl; 0.1 ⁇ z ⁇ 0.35 or
- This compound can be chosen from
- X denotes one or more halogen atoms from Cl, Br and I and followed by a treatment, for example prepared by mechanical grinding followed by a heat treatment.
- the binder can be chosen from polyvinylidene fluoride (PVDF) and its copolymers, polytetrafluoroethylene (PTFE) and its copolymers, polyacrylonitrile (PAN), poly(methyl)- or (butyl)methacrylate, polyvinyl chloride (PVC) , poly(vinyl formal), polyester, block polyetheramides, polymers of acrylic acid, methacrylic acid, acrylamide, itaconic acid, sulfonic acid, elastomer and cellulosic compounds.
- PVDF polyvinylidene fluoride
- PTFE polytetrafluoroethylene
- PAN polyacrylonitrile
- PVC poly(methyl)- or (butyl)methacrylate
- PVC polyvinyl chloride
- polyester block polyetheramides, polymers of acrylic acid, methacrylic acid, acrylamide, itaconic acid, sulfonic acid, elastomer and cellulosic
- the elastomer or elastomers that can be used as binder can be chosen from styrene-butadiene (SBR), butadiene-acrylonitrile (NBR), hydrogenated butadiene-acrylonitrile (HNBR), and a mixture of several of these.
- SBR styrene-butadiene
- NBR butadiene-acrylonitrile
- HNBR hydrogenated butadiene-acrylonitrile
- the electronically conductive compound is generally carbon black.
- a possible process for the preparation of the composition of cathodic active material is as follows:
- the solid electrolyte of the cathode is synthesized by mechanosynthesis, that is to say high-energy mechanical-chemical grinding, by grinding a mixture of precursors of the solid electrolyte.
- the high-energy mechanical-chemical grinding of the Li2S and P2S5 precursors leads to the compound of formula Li x PS y where 1.4 ⁇ x ⁇ 1.6 and 3 ⁇ y ⁇ 3.5.
- the solid electrolyte is obtained in the form of a powder.
- a powder is prepared from a mixture comprising a composite of elemental solid sulfur and carbon and generally one or more binder(s) and at least one electronically conductive compound.
- the particles of elemental sulfur are incorporated into the pores of the porous structure of the carbon. This is done by mixing porous carbon with solid elemental sulfur. Typically, the mass of solid elemental sulfur is 30-90% or 55-65% of the sum of the masses of solid elemental sulfur and carbon. The mass of carbon is typically 70 to 10% or 45 to 35% of the sum of the masses of solid elemental sulfur and carbon.
- the mixture is preferably heated to a temperature close to 155° C. for about 5 hours, under vacuum, to allow the sulfur molecules to penetrate into the open pores of the carbon. Around 155°C, sulfur in the liquid state has its lowest viscosity.
- the mixture is then heated under inert gas at a temperature between 200°C and 350°C for about 30 minutes, which has the effect of sublimating the sulfur and eliminating the excess.
- the product obtained is then generally mixed with at least one binder and at least one good electronic conductor compound.
- a powder comprising the composite S-C is obtained.
- the solid electrolyte powder is mixed with the powder comprising the SC composite, for example using a planetary grinder.
- the mixture may for example comprise from 30% to 60%, preferably approximately 50% by mass of the solid electrolyte powder and from 70% to 40%, preferably approximately 50% by mass of the powder comprising the composite S- C.
- a composition of cathodic active material is thus obtained.
- the anode may consist of lithium or of an alloy based on lithium and a chemical element chosen from among Mg, Al, B, Zn, Ag, Si, Sn, In and C, preferably In.
- the anode may also consist of a layer of lithium metal on which is deposited an indium layer, the indium layer being in contact with the solid electrolyte layer. These two layers form an alloy of lithium and indium.
- a current collector for example made of copper, can be attached to the layer of lithium metal or of the lithium alloy.
- FIG. 1 represents an anode (2) comprising a layer made up of lithium or of an alloy of lithium and indium (8) joined to a current collector (9).
- the anode can also consist only of a sheet of lithium.
- the solid electrolyte (10) intended to separate the anode from the cathode can be identical to or different from that used in the manufacture of the composition of cathodic active material. It acts as a separator between the anode and the cathode, preventing the anode from coming into contact with the cathode but nevertheless allowing the transport of the l.i ions. Its thickness can vary between 10 ⁇ m and 1 mm. Preferably, the thickness of the separator is less than or equal to 100 ⁇ m. More preferably, it ranges from 10 ⁇ m to 50 ⁇ m. A thickness greater than 100 ⁇ m can penalize the mass capacity of the element.
- the cathode active material composition is deposited on a current collector, preferably made of copper, and the assembly is compressed to a pressure of the order of several tons per cm 2 , which allows the material composition active cathode from adhering to the current collector.
- an anode is attached to the free surface of the pellet consisting of the solid electrolyte powder.
- the anode is fixed by compression. It is not necessary to insert a separator between the anode and the cathode because the solid electrolyte fulfills this role.
- the essential steps of the method for manufacturing an element according to the invention are as follows: a ) provision of a first powder of a solid electrolyte, b) provision of a second powder of a carbon-sulfur composite, which powder optionally comprises an electronic conductor and one or more binders, c) mixing the first powder with the second powder to obtain a cathodic active material composition, e) compressing the cathodic active material composition, f) bringing the compressed cathodic active material composition into contact with a solid electrolyte, identical or different from the solid electrolyte present in the composition of cathodic active material and compression of the assembly obtained, g) bringing the composition of cathodic active material obtained in step f) into contact with a sheet of copper or consisting of an alloy based on copper or consisting of a metal other than copper, the metal being at least partially covered with a coating of copper or a
- the positioning of the cathode strip in step g) can be carried out before step f) of compression of the composition of cathode active material with the solid electrolyte.
- the essential steps of the manufacturing process of an element according to the invention are as follows: a) provision of a first powder of a solid electrolyte, b) provision of a second powder of a carbon-sulfur composite, which powder optionally comprises a electronic conductor and one or more binders, c) provision of a third powder consisting of copper or of a chemical compound containing copper, d) mixing of the three powders to obtain a composition of cathodic active material, e) compression of the cathodic active material composition, f) bringing the compressed cathodic active material composition into contact with a solid electrolyte, identical to or different from the solid electrolyte present in the cathodic active material composition and compressing the assembly o bheld, g) bringing the assembly obtained in step f) into contact with a strip and compressing the assembly obtained, h
- the positioning of the strip of step g) can be carried out before step f) of compression of the composition of cathodic active material with the solid electrolyte.
- the quantity of the element copper present in the cathode is less than or equal to 0.37 grams of copper per ampere. time charged by the item.
- the quantity of copper per charged ampere hour is known to the operator who manufactures the element. Indeed, on the one hand, the operator knows the quantity of copper introduced into the element, whether the copper is introduced in the form of a metal collector or of a copper powder or of a compound chemical containing copper. If it is introduced in the form of a copper-based compound, knowing the molecular molar mass of this compound makes it possible to know the number of moles of the compound and to deduce the equivalent copper mass therefrom.
- the number of ampere hours charged can be obtained from knowledge of the mass of sulfur used in the element and the theoretical mass capacity of sulfur which is 1670 mAh per gram of sulfur. (Generally, the electrochemical capacity of elemental sulfur of the cathode is lower than that of lithium of the anode. The capacity of elemental sulfur limits the capacity of the element).
- the number of ampere-hours charged can also be determined by slowly charging the element at ambient temperature, for example at a rate of C/50 or slower, as carried out in the examples of figures 2 and 4.
- the nCu/nLi ratio must be greater than or equal to 0.04 and less than 0.81, preferably less than 0.5. If the quantity of copper in the cathode is greater than 0.37 g per ampere hour charged by the element or if the nCu/nLi ratio is greater than or equal to 0.81, the quantity of Cu + or Cu 2+ ions formed in the electrolyte during charging will be too great and may migrate towards the anode and be reduced there to Cu metal. The formation of Cu metal in the vicinity of the anode could lead to the formation of copper dendrites liable to be the cause of an internal short circuit between the anode and the cathode.
- the number of moles of copper nCu can be obtained by dividing the mass of copper used by the molar mass of copper or by dividing the mass of the copper-based compound used by its molecular molar mass.
- the number of moles of lithium nLi can be calculated from knowledge of the mass of the lithium-based compound used in the element and the molecular molar mass of this compound.
- a gravimetric capacity of at least about 2000 mAh per gram of sulfur in the S-C composite can be achieved for discharge at room temperature, preferably at least about 2500 mAh/g.
- the electrochemical element according to the invention can be advantageously used in fields in which electrochemical elements having a higher specific energy than that of lithium-ion elements are sought. Mention may be made of the space domain (satellites) and the aeronautical domain. Examples 1 to 3
- Element 1 differs from comparative element 1 by the nature of the strip of the cathode which is made of copper instead of aluminum for the strip of comparative element 1.
- the elements have undergone a charge-discharge cycle.
- the elements have been tested under a pressure of 100 MPa.
- the variation of the voltage as a function of the charged or discharged capacitance is represented in FIG. 2. It can be seen that the charged and discharged capacitances of the element 1 according to the invention comprising a copper current collector are greater than those of the element 1 comparative comprising an aluminum current collector.
- the discharge capacity of the element 1 according to the invention is 2500 mAh per gram of sulfur in the S-C composite, whereas that of the comparative element 1 is only about 1350 mAh per gram of sulfur in the S-C composite. This represents a significant capacity increase of approximately 85%.
- Element 2 outside the invention differs from comparative element 2 by the nature of the strip of the cathode which is made of copper instead of aluminum for the strip of comparative element 2. Variation curves voltage of these two elements during the first two cycles are shown in Figure 4.
- the first cycling phase is a discharge phase. It can be seen that after the initial phase of discharge (dchi in FIG. 4), the two elements have similar discharged capacities (0.31 mAh for element 2 outside the invention and 0.40 mAh for comparative element 2) .
- the charged capacity of element 2 outside the invention is 3.5 mAh. That of the comparative element 2 is only 0.39 mAh.
- the capacity of element 2 outside the invention is 3.2 mAh. That of the comparative element 2 is only 0.45 mAh.
- Element 3 according to the invention differs from comparative element 3 by the nature of the strip of the cathode which is made of copper instead of being aluminum for the strip of comparative element 3.
- FIG. 5 represents the charging and discharging voltage curves of the comparative element 3 and of the element 3 according to the invention as a function of the discharged capacity (mAh). It can be seen that the charged and discharged capacities of the element 3 according to the invention comprising a copper current collector are greater than those of the comparative element 3 comprising an aluminum current collector.
- the discharge capacity of the element 3 according to the invention is 2.5 mAh whereas that of the comparative element 3 is only about 0.35 mAh per gram of sulfur in the S-C composite, i.e. a multiplication by 7 of the capacity.
- FIG. 6 represents the charging and discharging voltage curves of the element 3 according to the invention at cycles no. 3, 4, 5 and 6 as a function of the capacity of the element per gram of sulfur in the SC-composite.
- the discharged capacity is between 8000 and 9000 mAh per gram of sulfur in the SC composite.
- the capacitance discharged by comparative element 3 is much lower as shown in FIG. 7 which represents the charging and discharging voltage curves of comparative element 3 at cycles n° 1 and 8 as a function of the capacity of the element per gram of sulfur in the composite SC.
- the discharged capacity is only about 1200 mAh per gram of sulfur in the SC composite.
- the electrochemical element is charged to a voltage of 2.7V.
- the element made up of a positive and negative electrode surface S, is disassembled and then placed in a sealed container of known volume (V) equipped with a septum and a pressure and temperature sensor.
- a quantity of water, mEEO, equal to 5 times the mass of the element, is introduced into the container using a needle to react all the lithium metal which is transformed into hydrogen.
- the container is then opened, then the collector of the negative electrode is extracted before carrying out the following steps.
- the rest of the element is then placed in a beaker.
- a solution of KMnCU at 1 mol/L is then added to the container so as to oxidize the sulphide ions of the electrolyte, giving VK the volume of this solution.
- This step then makes it possible to attack the entire element with a concentrated acid solution having the effect of dissolving all the constituents while avoiding the formation of FUS, i.e. V ac the volume of acid making it possible to reach a pH of the solution after etching equal to 1.
- the concentrations of lithium Cu and copper Cc u can then be measured by ICP
- nCu/nLi ratio of the electrolyte is equal to the ratio of the quantities Ncu and Nu previously calculated divided by the surface area S of the electrode.
- the element in example 1 differs from the reference example in that it contains copper in its cathode.
- the volume capacity changes from 3000 mAh/cc (Cu+S) for the element of the reference example to 3106 mAh/cc (Cu+S) for the element of example 1. no short circuit.
- examples 9 to 15 are comparative. They have a high copper content and have short circuits. These elements are characterized either by a mass of copper per Ah of sulfur greater than 0.37 g/Ah (Examples 9 to 14), or by an nCu/nLi ratio greater than 0.81 (Example 15).
- examples 3 and 4 contain 40 mg of solid electrolyte between the anode and the cathode. This high quantity of solid electrolyte strongly penalizes the mass capacity because it is only 551 and 452 mAh/g (Cu+S).
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Abstract
An all-solid-state lithium-sulphur electrochemical element comprising: a) at least one cathode comprising a cathode active material composition comprising: i) elemental sulphur, ii) carbon, iii) a solid electrolyte, the cathode comprising copper; b) at least one anode the active material of which is lithium or a lithium-based alloy, c) a solid electrolyte which is positioned between the at least one cathode and the at least one anode, and which is identical to or different from the solid electrolyte present in the cathode active material composition, the amount of copper in the cathode being less than or equal to 0.37 g per ampere-hour charged by the element, the ratio nCu/nLi in the element, when said element is in the charged state, being greater than or equal to 0.04 and less than 0.81, wherein nCu represents the mole number of copper and nLi represents the sum of the mole numbers of lithium in the solid electrolyte of the cathode and in the solid electrolyte positioned between the at least one cathode and the at least one anode.
Description
Description Description
Titre : ÉLÉMENT ÉLECTROCHIMIQUE LITHIUM-SOUFRE TOUT SOLIDE Title: ALL SOLID LITHIUM-SULFUR ELECTROCHEMICAL ELEMENT
Domaine technique de l’invention Technical field of the invention
[0001] Le domaine technique de l’invention est celui des éléments électrochimiques lithium- soufre tout solide ainsi que celui des procédés d’assemblage de tels éléments. [0001] The technical field of the invention is that of all-solid lithium-sulphur electrochemical elements as well as that of methods for assembling such elements.
Contexte de l'invention Background of the invention
[0002] Le terme « élément » utilisé dans ce qui suit désigne un élément électrochimique. Les termes « élément » et « élément électrochimique » sont utilisés de manière interchangeable dans ce qui suit. Les éléments électrochimiques lithium/soufre (Li/S) comprenant un électrolyte liquide sont connus de l’état de la technique. Ils comprennent typiquement au moins une électrode positive (cathode) de soufre élémentaire, un électrolyte liquide organique et au moins une électrode négative (anode) en lithium métal ou en alliage métallique de lithium. La cathode est généralement composite, c’est-à-dire qu’elle est préparée à partir de soufre élémentaire et d’additifs non électrochimiquement actifs. Comme additifs non élec- trochimiquement actifs, on peut citer un conducteur électronique, tel que le carbone, permettant d’améliorer la conductivité électronique de la cathode car le soufre est un isolant électronique. On peut aussi citer un ou plusieurs liants polymériques permettant d’assurer la cohésion entre les différents matériaux de la cathode. En raison de la faible masse atomique du lithium et de la masse modérée du soufre, les éléments électrochimique Li/S sont relativement légers. Ils constituent une alternative prometteuse aux éléments lithium-ion en raison de leur densité énergétique plus élevée et le faible coût du soufre. [0002] The term "element" used in the following denotes an electrochemical element. The terms “element” and “electrochemical element” are used interchangeably in the following. Lithium/sulfur (Li/S) electrochemical elements comprising a liquid electrolyte are known from the state of the art. They typically comprise at least one positive electrode (cathode) of elemental sulfur, an organic liquid electrolyte and at least one negative electrode (anode) of lithium metal or lithium metal alloy. The cathode is usually composite, i.e. it is prepared from elemental sulfur and non-electrochemically active additives. As non-electrochemically active additives, mention may be made of an electronic conductor, such as carbon, making it possible to improve the electronic conductivity of the cathode because sulfur is an electronic insulator. Mention may also be made of one or more polymeric binders making it possible to ensure cohesion between the different materials of the cathode. Due to the low atomic mass of lithium and the moderate mass of sulfur, Li/S electrochemical elements are relatively light. They are a promising alternative to lithium-ion cells due to their higher energy density and low sulfur cost.
[0003] Partant d’une cathode de soufre élémentaire et d’une anode de lithium métal ou d’un alliage de lithium, l’élément électrochimique se trouve initialement à l’état chargé. En décharge, le soufre élémentaire de la cathode se réduit en sulfure de lithium Li2S et le lithium métallique ou l’alliage métallique de lithium s’oxyde à l’anode. Les réactions suivantes ont lieu aux électrodes : [0003] Starting from a cathode of elemental sulfur and an anode of lithium metal or a lithium alloy, the electrochemical element is initially in the charged state. In discharge, the elemental sulfur of the cathode is reduced to lithium sulphide Li2S and the metallic lithium or the metallic lithium alloy is oxidized at the anode. The following reactions take place at the electrodes:
Cathode : Ss + 16 e' — > 8 S2' Cathode: Ss + 16 e' — > 8 S 2 '
Anode : Li — > Li+ + e' Anode: Li — > Li + + e'
La réaction globale de décharge de l’élément est : 16 Li + Sx — > 8 Li2S The overall cell discharge reaction is: 16 Li + Sx — > 8 Li2S
[0004] A la différence d’un élément électrochimique lithium-ion, un élément électrochimique lithium/soufre comprend typiquement un électrolyte dont le solvant est à base d’éthers. Les éthers, tels que le 1,3-dioxolane ou le tétrahydrofurane sont utilisés depuis plusieurs décennies et permettent une solubilisation importante des polysulfures de lithium. Les solvants organiques de type glyme de formule générale EI-fO-CEE-CEEJn-OEI, tels que le 1,2-dimé- thoxyéthane (DME), sont aussi fréquemment utilisés comme solvant de l’électrolyte. [0004] Unlike a lithium-ion electrochemical cell, a lithium/sulfur electrochemical cell typically comprises an electrolyte whose solvent is based on ethers. Ethers, such as 1,3-dioxolane or tetrahydrofuran have been used for several decades and allow significant solubilization of lithium polysulphides. Organic solvents of the glyme type with the general formula EI-fO-CEE-CEEJn-OEI, such as 1,2-dimethoxyethane (DME), are also frequently used as solvent for the electrolyte.
[0005] Au cours de la réduction du soufre qui se produit lors de la décharge de l’élément, les molécules cycliques de soufre (sous forme d’octasoufre Ss) sont réduites et forment des
chaines linéaires de polysulfures de lithium, de formule générale Li2Sn, n allant généralement de 2 à 8. Les premiers composés formés au cours de la décharge de l’élément sont les polysulfures de lithium à chaines longues, tels que Li2Ss ou Li2Se. Les polysulfures de lithium à chaines longues sont susceptibles de migrer à travers l’électrolyte et d’atteindre l’anode de lithium où elles seront réduites en polysulfures à chaines courtes au cours de la charge qui suit la décharge de l’élément. Les polysulfures à chaines courtes retournent vers la cathode où ils sont de nouveau réoxydés en polysulfures à chaines longues, et ainsi de suite. Ce mécanisme de navette (« shuttle ») des polysulfures entre l’anode et la cathode est la cause d’un faible rendement coulombique de l’élément, c’est-à-dire un faible ratio entre la capacité déchargée par l’élément et la capacité chargée dans l’élément au cours de la charge ayant précédé la décharge. De plus, il entraine une forte autodécharge, ainsi qu’une dégradation de la durée de vie de l’élément en cyclage. [0005] During the reduction of sulfur which occurs during the discharge of the element, the cyclic molecules of sulfur (in the form of octasulfur Ss) are reduced and form linear chains of lithium polysulphides, of general formula Li2S n , n generally ranging from 2 to 8. The first compounds formed during the discharge of the element are the long-chain lithium polysulphides, such as Li2Ss or Li2Se. Long-chain lithium polysulfides are likely to migrate through the electrolyte and reach the lithium anode where they will be reduced to short-chain polysulfides during charging following cell discharge. The short-chain polysulfides return to the cathode where they are again reoxidized to long-chain polysulfides, and so on. This shuttle mechanism (“shuttle”) of the polysulphides between the anode and the cathode is the cause of a low coulombic efficiency of the element, that is to say a low ratio between the capacity discharged by the element and the capacitance charged in the element during the charge preceding the discharge. In addition, it leads to a high self-discharge, as well as a deterioration in the life of the element in cycling.
[0006] Par ailleurs, l’électrolyte liquide d’un élément électrochimique Li/S peut, en cas d’emballement thermique de l’élément, réagir de façon exothermique avec les matières actives des électrodes négative et positive et dans certains cas, les éléments peuvent prendre feu, ce qui constitue un risque pour la sécurité de l’utilisateur. Furthermore, the liquid electrolyte of an Li/S electrochemical element can, in the event of thermal runaway of the element, react exothermically with the active materials of the negative and positive electrodes and in certain cases, the elements can catch fire, posing a safety risk to the user.
[0007] Le remplacement d’un électrolyte liquide par un électrolyte solide offre une solution au risque d’emballement thermique. En utilisant un électrolyte solide, on supprime la réaction exothermique entre les matières actives et l’électrolyte, ce qui améliore considérablement la sécurité pour l’utilisateur. De plus, on empêche la fuite d’électrolyte liquide hors du conteneur de l’élément en cas d’ouverture du conteneur, lorsque l’élément est placé dans des conditions extrêmes (choc porté à l’élément, surpression dans le conteneur causée par une augmentation de chaleur, etc.). Enfin, le remplacement d’un électrolyte liquide par un électrolyte solide offre une solution au problème du mouvement de navettes des polysulfures de lithium dans l’électrolyte liquide. La nature solide de l’électrolyte empêche en effet le mouvement de navettes des polysulfures de lithium. [0007] Replacing a liquid electrolyte with a solid electrolyte offers a solution to the risk of thermal runaway. By using a solid electrolyte, the exothermic reaction between the active materials and the electrolyte is suppressed, which considerably improves safety for the user. In addition, leakage of liquid electrolyte from the cell container is prevented in the event of the container being opened, when the cell is placed under extreme conditions (shock to the cell, overpressure in the container caused by an increase in heat, etc.). Finally, the replacement of a liquid electrolyte by a solid electrolyte offers a solution to the problem of the shuttle movement of lithium polysulphides in the liquid electrolyte. The solid nature of the electrolyte in fact prevents the shuttle movement of the lithium polysulphides.
[0008] Le document EP-A-3 012 887 décrit un élément Li/S « tout solide » comprenant : Document EP-A-3 012 887 describes an “all-solid” Li/S element comprising:
- une cathode comprenant une couche composite, - a cathode comprising a composite layer,
- une anode, et - an anode, and
- un électrolyte solide, la couche composite de la cathode comprenant un mélange des trois composés suivants :- a solid electrolyte, the composite layer of the cathode comprising a mixture of the following three compounds:
A) un matériau conducteur ionique contenant du phosphore en un ratio massique allant de 0,2 à 0,55 par rapport à la masse du matériau conducteur ionique ; A) an ionically conductive material containing phosphorus in a mass ratio ranging from 0.2 to 0.55 relative to the mass of the ionically conductive material;
B) du soufre et/ou un produit dérivé du soufre produit par la décharge de l’élément ; etB) sulfur and/or a sulfur by-product produced by the discharge of the element; and
C) un matériau conducteur électronique, tel que le noir de carbone, le composé B) représentant au moins 40% en masse de la somme des masses des composés A), B) et C). C) an electronically conductive material, such as carbon black, compound B) representing at least 40% by mass of the sum of the masses of compounds A), B) and C).
Il est dit que cet élément présente une bonne capacité en charge et en décharge, qu’il soit traversé aussi bien par un courant de faible intensité (par exemple de 0,5 à 1 mA/cm2) que par un courant de forte intensité (par exemple plus de 5 mA/cm2). It is said that this element has a good capacity in charge and in discharge, that it is crossed as well by a low intensity current (for example from 0.5 to 1 mA/cm 2 ) as by a high intensity current (for example more than 5 mA/cm 2 ).
[0009] L’article « High loading CuS-based cathodes for all-solid-state lithium sulfur batteries with
enhanced volumetric capacity » S.M. Hosseini, A. Varzi, S. Ito, Y. Aihara, S. Passerini, publié dans Energy Storage Materials, https://doi.Org/10.1016/j.ensm.2020.01.022 décrit l’effet de l’ajout de composites de sulfure de cuivre-soufre-carbone dans la cathode d’un élément Li/S sur les performances d’un tel élément. Cet article ne donne aucune indication quant à la quantité de cuivre à ajouter à la cathode pour minimiser le risque de survenue de courts-circuits. [0009] The article “High loading CuS-based cathodes for all-solid-state lithium sulfur batteries with enhanced volumetric capacity” SM Hosseini, A. Varzi, S. Ito, Y. Aihara, S. Passerini, published in Energy Storage Materials, https://doi.Org/10.1016/j.ensm.2020.01.022 describes the effect of the addition of copper sulphide-sulphur-carbon composites in the cathode of a Li/S element on the performance of such an element. This article gives no indication as to how much copper to add to the cathode to minimize the risk of short circuits occurring.
[0010] Le document JP 6716324 décrit un élément électrochimique lithium-soufre tout solide comprenant : a) une cathode comprenant une matière active d’électrode contenant un composite soufre- carbone et un métal tel que le cuivre ; b) une anode dont la matière active est du lithium ; c) un électrolyte solide hydrure tel que LiBbL. [0010] Document JP 6716324 describes an all-solid lithium-sulfur electrochemical element comprising: a) a cathode comprising an electrode active material containing a sulfur-carbon composite and a metal such as copper; b) an anode whose active material is lithium; c) a solid hydride electrolyte such as LiBbL.
Dans la cathode, le soufre, le carbone et le métal sont mélangés pour obtenir un mélange dans lequel le métal est uniformément dispersé dans le composite soufre-carbone. La cathode peut également contenir LiBEL en une masse égale à la masse du mélange. La quantité de cuivre utilisée est faible. Elle correspond à un ratio nCu/nLi de 0,00245 où nCu désigne le nombre de mole de cuivre et nLi désigne la somme des nombres de mole de lithium dans l’électrolyte solide de la cathode et dans l’électrolyte solide intercalé entre la cathode et l’anode. Aune si faible concentration en cuivre, l’amélioration de la capacité volumique de l’élément n’est pas significative. In the cathode, sulfur, carbon and metal are mixed to obtain a mixture in which the metal is uniformly dispersed in the sulfur-carbon composite. The cathode can also contain LiBEL in a mass equal to the mass of the mixture. The amount of copper used is small. It corresponds to an nCu/nLi ratio of 0.00245 where nCu denotes the number of moles of copper and nLi denotes the sum of the numbers of moles of lithium in the solid electrolyte of the cathode and in the solid electrolyte inserted between the cathode and the anode. At such a low copper concentration, the improvement in the volumetric capacity of the element is not significant.
[0011] On cherche à améliorer la capacité électrochimique volumique d’un élément Li/S comportant un électrolyte solide tout en minimisant le risque d’observer un court-circuit de l’élément au cours de son fonctionnement. On cherche un élément Li/S présentant une capacité d’au moins 2000 mAh, de préférence d’au moins 2500 mAh, par gramme de soufre pour une décharge à température ambiante. On cherche également un élément Li/S comportant un électrolyte solide présentant une faible baisse de capacité au cours d’un fonctionnement en cyclage [0011] It is sought to improve the volume electrochemical capacity of a Li/S element comprising a solid electrolyte while minimizing the risk of observing a short-circuit of the element during its operation. We are looking for a Li/S cell with a capacity of at least 2000 mAh, preferably at least 2500 mAh, per gram of sulfur for discharge at room temperature. We are also looking for a Li/S element comprising a solid electrolyte with a low drop in capacity during cycling operation.
Résumé de l'invention Summary of the invention
[0012] A cet effet, l’invention propose un élément électrochimique lithium-soufre tout solide comprenant : a) au moins une cathode comprenant une composition de matière active cathodique comprenant ; i) du soufre élémentaire, ii) du carbone, iii) un électrolyte solide, la cathode comprenant du cuivre, b) au moins une anode dont la matière active est du lithium ou un alliage à base de lithium, c) un électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode, identique ou différent de l’électrolyte solide présent dans la composition de matière active cathodique, la quantité de cuivre dans la cathode étant inférieure ou égale à 0,37 g par ampère heure
chargé par l’élément, le rapport nCu/nLi dans l’élément à l’état chargé étant supérieur ou égal à 0,04 et inférieur à 0,81 où nCu désigne le nombre de mole de cuivre et nLi désigne la somme des nombres de mole de lithium dans l’électrolyte solide de la cathode et dans l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode. To this end, the invention provides an all-solid lithium-sulfur electrochemical element comprising: a) at least one cathode comprising a composition of cathodic active material comprising; i) elemental sulphur, ii) carbon, iii) a solid electrolyte, the cathode comprising copper, b) at least one anode whose active material is lithium or a lithium-based alloy, c) a solid electrolyte intercalated between said at least one cathode and said at least one anode, identical to or different from the solid electrolyte present in the cathodic active material composition, the amount of copper in the cathode being less than or equal to 0.37 g per ampere hour charged by the element, the nCu/nLi ratio in the element in the charged state being greater than or equal to 0.04 and less than 0.81 where nCu denotes the number of moles of copper and nLi denotes the sum of the numbers mole of lithium in the solid electrolyte of the cathode and in the solid electrolyte interposed between said at least one cathode and said at least one anode.
[0013] Il a été découvert que la présence du cuivre dans la cathode permettait d’augmenter la capacité électrochimique de l’élément. L’augmentation de capacité électrochimique de l’élément est réversible. En effet, l’élément peut être soumis à plusieurs cycles sans connaître de baisse significative de sa capacité. Il a été découvert de plus que le choix d’une quantité maximale de cuivre de 0,37 g par ampère heure chargé de l’élément associé au choix d’un ratio nCu/nLi supérieur ou égal à 0,04 et inférieur à 0,81 permettait de minimiser le risque de survenue d’un court-circuit dans l’élément, donc d’allonger sa durée de vie. [0013] It was discovered that the presence of copper in the cathode made it possible to increase the electrochemical capacity of the element. The increase in electrochemical capacity of the element is reversible. Indeed, the element can be subjected to several cycles without experiencing a significant drop in its capacity. It was further discovered that the choice of a maximum quantity of copper of 0.37 g per charged ampere hour of the element associated with the choice of an nCu/nLi ratio greater than or equal to 0.04 and less than 0 .81 made it possible to minimize the risk of occurrence of a short circuit in the element, thus extending its life.
[0014] Selon un mode de réalisation, le cuivre est présent sous l’une ou plusieurs des formes a, P et y suivantes : a) sous la forme d’un collecteur métallique servant de collecteur de courant de la cathode, le collecteur métallique étant constitué de cuivre ou d’un alliage à base de cuivre ou étant constitué d’un métal au moins partiellement recouvert d’un revêtement de cuivre ou d’un alliage à base de cuivre, According to one embodiment, the copper is present in one or more of the following forms a, P and y: a) in the form of a metal collector serving as a current collector of the cathode, the metal collector being made of copper or a copper-based alloy or being made of a metal at least partially covered with a coating of copper or a copper-based alloy,
P) sous la forme d’une poudre de cuivre incorporée à la composition de matière active cathodique, y) SOUS la forme d’un composé chimique contenant du cuivre incorporé à la composition de matière active cathodique. P) in the form of a copper powder incorporated into the composition of cathodic active material, y) IN the form of a chemical compound containing copper incorporated into the composition of cathodic active material.
[0015] Selon un mode de réalisation, l’électrolyte solide de la composition de matière active cathodique et/ou l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode est un composé soufré. According to one embodiment, the solid electrolyte of the cathodic active material composition and/or the solid electrolyte interposed between said at least one cathode and said at least one anode is a sulfur compound.
[0016] Selon un mode de réalisation, la quantité de cuivre présente dans la cathode est inférieure ou égale à 0,12 g par ampère heure chargé par l’élément, de préférence égale à 0,06 ± 0,03 g par ampère heure. According to one embodiment, the quantity of copper present in the cathode is less than or equal to 0.12 g per ampere hour charged by the element, preferably equal to 0.06 ± 0.03 g per ampere hour. .
[0017] Selon un mode de réalisation, le rapport nCu/nLi est inférieur à 0,5, de préférence inférieur à 0,3. According to one embodiment, the nCu/nLi ratio is less than 0.5, preferably less than 0.3.
[0018] Selon un mode de réalisation, l’électrolyte solide utilisé dans la cathode ou intercalé entre l’anode et la cathode lors de l’assemblage de l’élément est sous forme d’une poudre, la poudre étant recouverte de cuivre ou d’un composé contenant du cuivre. According to one embodiment, the solid electrolyte used in the cathode or interposed between the anode and the cathode during assembly of the element is in the form of a powder, the powder being covered with copper or of a compound containing copper.
[0019] Selon un mode de réalisation, l’électrolyte solide de la composition de matière active cathodique et l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode sont choisis dans le groupe consistant en : According to one embodiment, the solid electrolyte of the cathodic active material composition and the solid electrolyte interposed between said at least one cathode and said at least one anode are chosen from the group consisting of:
- LixPSy où 1,4 <x < 1,6 et 3 <y < 3,5, susceptible d’être obtenu à partir des précurseurs Li2S et P2S5, - Li x PSy where 1.4 <x < 1.6 and 3 <y < 3.5, likely to be obtained from Li 2 S and P 2 S 5 precursors,
- un composé de formule (l-y)Li3PS4.yLiX où X désigne un atome d’halogène avec 0,05 < Y < 0,40, - a compound of formula (l-y)Li3PS4.yLiX where X denotes a halogen atom with 0.05 < Y < 0.40,
- un composé de formule (Li2S)a(P2S5)b(LiX)c(Li2O)d avec a+b+c+d=l,
- LiePSsX où X désigne un atome d’halogène, susceptible d’être obtenu à partir des précurseurs I 2S, P2S5 et LiX, - a compound of formula (Li 2 S) a (P 2 S5)b(LiX) c (Li 2 O)d with a+b+c+d=l, - LiePSsX where X denotes a halogen atom, which can be obtained from the precursors I 2S, P2S5 and LiX,
- un mélange de LiePSsX avec une solution solide de LiX-LiBFL où X est un halogène,- a mixture of LiePSsX with a solid solution of LiX-LiBFL where X is a halogen,
- un composé argyrodite éventuellement substitué par du borohydrure, ayant pour formule Li7-xPS6-xXx.z(BH4)z dans laquelle X est choisi dans le groupe consistant en Cl, Br, I, F et CN ; 0<x<2 et 0<z<0,50, et - an argyrodite compound optionally substituted by borohydride, having the formula Li 7 -xPS6-xX x .z(BH 4 )z in which X is chosen from the group consisting of Cl, Br, I, F and CN; 0<x<2 and 0<z<0.50, and
- un mélange des composés Li2S/P2S/LiCl/LiBr/LiX, X désigne un ou plusieurs atomes d’halogène parmi Cl, Br et I après traitement thermique du mélange. - a mixture of Li2S/P2S/LiCl/LiBr/LiX compounds, X designates one or more halogen atoms from Cl, Br and I after heat treatment of the mixture.
[0020] Selon un mode de réalisation, l’électrolyte solide a pour formule Li7-xPS6-xXx-z(BH4)z dans laquelle X est I ; x=l et 0,l<z<0,35. According to one embodiment, the solid electrolyte has the formula Li7-xPS6-xXx-z(BH4) z in which X is I; x=1 and 0.1<z<0.35.
[0021] Selon un mode de réalisation, l’électrolyte solide est choisi parmi LiePSsI, LiePSsCl, LiePS5lo,9o(BH4)o,io, LiePS5lo,83(BH4)o,i7, Li6PSsIo,67(BH4)o,33, LiePS5lo,5o(BH4)o,5o et LiePS5Clo,83(BH4)o,i7. According to one embodiment, the solid electrolyte is chosen from LiePSsI, LiePSsCl, LiePS5lo,9o(BH4)o,io, LiePS5lo,83(BH4)o,i7, Li6PSsIo,67(BH4)o,33, LiePS5lo,5o(BH4)o,5o and LiePS5Clo,83(BH4)o,i7.
[0022] Selon un mode de réalisation, l’électrolyte solide de la composition de matière active cathodique a pour formule LixPSy où 1,4 <x < 1,6 et 3 <y < 3,5 et l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode est choisi parmi :According to one embodiment, the solid electrolyte of the cathodic active material composition has the formula Li x PS y where 1.4 <x <1.6 and 3 <y <3.5 and the solid electrolyte inserted between said at least one cathode and said at least one anode is chosen from:
- un composé de formule Li7-xPS6-xXx-z(BH4)z dans lequel X est choisi dans le groupe consistant en Cl, Br, I, F et CN ; 0<x<2 et 0<z<0,50, et - a compound of formula Li7-xPS6-xXx-z(BH4) z wherein X is selected from the group consisting of Cl, Br, I, F and CN; 0<x<2 and 0<z<0.50, and
- un mélange des composés Li2S/P2S/LiCl/LiBr/LiX, X désigne un ou plusieurs atomes d’halogène parmi Cl, Br et I suivi d’un traitement thermique du mélange. - a mixture of Li2S/P2S/LiCl/LiBr/LiX compounds, X denotes one or more halogen atoms from Cl, Br and I followed by heat treatment of the mixture.
[0023] Selon un mode de réalisation, l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode a pour formule LiePSsL/e BFLji/e. According to one embodiment, the solid electrolyte interposed between said at least one cathode and said at least one anode has the formula LiePSsL/e BFLji/e.
[0024] Selon un mode de réalisation, l’alliage est un alliage de lithium et d’un ou plusieurs éléments chimiques choisis dans le groupe consistant en l’indium, le silicium, l’étain et le carbone. According to one embodiment, the alloy is an alloy of lithium and one or more chemical elements chosen from the group consisting of indium, silicon, tin and carbon.
Brève description des figures Brief description of figures
[0025] [Fig. 1] est une vue en coupe schématique de l’élément lithium-soufre selon l’invention. [0025] [Fig. 1] is a schematic sectional view of the lithium-sulfur element according to the invention.
[0026] [Fig. 2] représente les courbes de charge et de décharge de l’élément 1 comparatif et de l’élément 1 selon l’invention. La charge et la décharge ont été réalisées à température ambiant à un régime de charge de C/50 et D/50. [0026] [Fig. 2] represents the charge and discharge curves of the comparative element 1 and of the element 1 according to the invention. Charging and discharging were carried out at room temperature at a charging rate of C/50 and D/50.
[0027] [Fig. 3] représente la variation de la capacité en décharge par gramme de soufre au cours d’un cyclage de l’élément 1 selon l’invention à température ambiante. Les phases de charge sont menées à un régime de C/10 jusqu’à une tension de 2,3 V. Les phases de décharge sont menées à un régime de décharge de D/5 jusqu’à une tension d’arrêt. [0027] [Fig. 3] represents the variation in discharge capacity per gram of sulfur during cycling of element 1 according to the invention at room temperature. The charge phases are carried out at a rate of C/10 up to a voltage of 2.3 V. The discharge phases are carried out at a discharge rate of D/5 up to a stop voltage.
[0028] [Fig. 4] représente les courbes de charge et de décharge de l’élément 2 comparatif et de l’élément 2 hors invention sur deux cycles. Charge au régime de C/50 et décharge au régime de D/50. [0028] [Fig. 4] represents the charge and discharge curves of comparative element 2 and of element 2 outside the invention over two cycles. Charge at C/50 rate and discharge at D/50 rate.
[0029] [Fig. 5] représente les courbes de tension en charge et en décharge de l’élément 3 comparatif et de l’élément 3 selon l’invention en fonction de la capacité déchargée (mAh). Charge au régime de C/20 et décharge au régime de D/20.
[0030] [Fig. 6] représente les courbes de tension en charge et en décharge de l’élément 3 selon l’invention aux cycles n°3, 4, 5 et 6 en fonction de la capacité de l’élément par gramme de soufre dans le composite S-C. Charge au régime de C/20 et décharge au régime de D/20. [0029] [Fig. 5] represents the charging and discharging voltage curves of the comparative element 3 and of the element 3 according to the invention as a function of the discharged capacity (mAh). Charge at C/20 rate and discharge at D/20 rate. [0030] [Fig. 6] represents the charging and discharging voltage curves of the element 3 according to the invention at cycles 3, 4, 5 and 6 as a function of the capacitance of the element per gram of sulfur in the composite SC. Charge at C/20 rate and discharge at D/20 rate.
[0031] [Fig. 7] représente les courbes de tension en charge et en décharge de l’élément 3 comparatif aux cycles n°l et 8 en fonction de la capacité de l’élément par gramme de soufre dans le composite S-C. Charge au régime de C/20 et décharge au régime de D/20. [0031] [Fig. 7] represents the charge and discharge voltage curves of element 3 compared to cycles 1 and 8 as a function of the capacity of the element per gram of sulfur in the S-C composite. Charge at C/20 rate and discharge at D/20 rate.
Description des modes de réalisation de l'invention Description of embodiments of the invention
[0032] L’invention repose sur la découverte de l’existence d’une interaction entre le cuivre et les constituants de la cathode. Cette interaction conduit à une augmentation de la capacité électrochimique de l’élément. La quantité de cuivre dans la cathode doit être inférieure ou égale à 0,37 g par ampère heure chargé par l’élément. De plus, le rapport nCu/nLi dans l’élément à l’état chargé doit être supérieur ou égal à 0,04 et inférieur à 0,81 où nCu désigne le nombre de mole de cuivre et nLi désigne la somme des nombres de mole de lithium dans l’électrolyte solide de la cathode et dans l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode. Le rapport nCu/nLi dans l’élément à l’état chargé peut être supérieur ou égal à 0,09 ou supérieur ou égal à 0,11 ou supérieur ou égal à 0,29 ou supérieur ou égal à 0,40 ou supérieur ou égal à 0,50 ou supérieur ou égal à 0,70. Il peut être inférieur ou égal à 0,09 ou inférieur ou égal à 0,11 ou inférieur ou égal à 0,29 ou inférieur ou égal à 0,40 ou inférieur ou égal à 0,50 ou inférieur ou égal à 0,70. The invention is based on the discovery of the existence of an interaction between copper and the constituents of the cathode. This interaction leads to an increase in the electrochemical capacity of the element. The amount of copper in the cathode must be less than or equal to 0.37 g per ampere hour charged by the element. In addition, the nCu/nLi ratio in the element in the charged state must be greater than or equal to 0.04 and less than 0.81 where nCu denotes the number of moles of copper and nLi denotes the sum of the numbers of moles of lithium in the solid electrolyte of the cathode and in the solid electrolyte interposed between said at least one cathode and said at least one anode. The nCu/nLi ratio in the cell in the charged state may be greater than or equal to 0.09 or greater than or equal to 0.11 or greater than or equal to 0.29 or greater than or equal to 0.40 or greater or equal to 0.50 or greater than or equal to 0.70. It can be less than or equal to 0.09 or less than or equal to 0.11 or less than or equal to 0.29 or less than or equal to 0.40 or less than or equal to 0.50 or less than or equal to 0.70 .
[0033] L’introduction de cuivre dans la cathode peut être réalisé de trois manières différentes : [0033] The introduction of copper into the cathode can be achieved in three different ways:
1) par l’emploi d’un collecteur métallique constitué de cuivre ou d’un alliage à base de cuivre ou par l’emploi d’un collecteur constitué d’un métal au moins partiellement recouvert d’un revêtement en cuivre ou en alliage à base de cuivre, 1) by the use of a metal collector made of copper or a copper-based alloy or by the use of a collector made of a metal at least partially covered with a copper or alloy coating copper-based,
2) par l’ajout dans la composition de matière active cathodique d’une poudre de cuivre,2) by adding copper powder to the cathodic active material composition,
3) par l’ajout dans la composition de matière active cathodique d’un composé chimique contenant du cuivre. 3) by adding a chemical compound containing copper to the cathodic active material composition.
[0034] L’introduction de cuivre peut se faire selon l’une ou plusieurs de ces trois manières. La structure de l’élément selon l’invention est représentée schématiquement sur la figure 1. L’élément comprend une cathode (1), une anode (2) et un électrolyte solide (3) intercalé entre l’anode et la cathode. La figure 1 représente un seul empilement d’une cathode, d’une couche d’électrolyte solide ayant le rôle de séparateur et d’une anode. Néanmoins, l’invention ne se limite pas à cette représentation schématique. Le faisceau électrochimique peut être constitué de plusieurs empilements. The introduction of copper can be done in one or more of these three ways. The structure of the element according to the invention is represented schematically in FIG. 1. The element comprises a cathode (1), an anode (2) and a solid electrolyte (3) inserted between the anode and the cathode. Figure 1 shows a single stack of a cathode, a layer of solid electrolyte acting as a separator and an anode. However, the invention is not limited to this schematic representation. The electrochemical bundle may consist of several stacks.
Cathode Cathode
[0035] La cathode (1) comprend un collecteur de courant (4) de préférence sous la forme d’un feuillard de cuivre ou d’un feuillard d’un alliage à base de cuivre. Le feuillard peut être plein ou perforé. Le collecteur de courant peut aussi être un feuillard métallique recouvert sur au moins une de ses faces par un revêtement en cuivre ou en alliage à base de cuivre. Le collecteur de courant peut aussi être une mousse de cuivre, un déployé de cuivre ou un feutre de cuivre. Alternativement, le collecteur de courant peut être un feuillard plein ou perforé constitué d’un métal autre que le cuivre, par exemple l’aluminium, et le cuivre est
apporté à la cathode soit sous la forme d’une poudre de cuivre incorporée à la composition de matière active cathodique, soit sous la forme d’un composé chimique contenant du cuivre. The cathode (1) comprises a current collector (4) preferably in the form of a copper strip or a strip of a copper-based alloy. The strap can be solid or perforated. The current collector can also be a metal strip covered on at least one of its faces with a copper or copper-based alloy coating. The current collector can also be a copper foam, an expanded copper or a copper felt. Alternatively, the current collector can be a solid or perforated strip made of a metal other than copper, for example aluminum, and copper is brought to the cathode either in the form of a copper powder incorporated into the composition of cathodic active material, or in the form of a chemical compound containing copper.
[0036] La composition de matière active cathodique déposée sur au moins l’une des faces du collecteur de courant comprend les constituants suivants : The cathodic active material composition deposited on at least one of the faces of the current collector comprises the following constituents:
- un composite (5) préparé à partir de soufre solide élémentaire et de carbone. - a composite (5) prepared from elemental solid sulfur and carbon.
- un électrolyte solide (7), et - a solid electrolyte (7), and
- généralement un ou plusieurs liant(s) et au moins un composé conducteur électronique (6). - generally one or more binder(s) and at least one electronically conductive compound (6).
[0037] Le soufre solide élémentaire existe sous différentes formes moléculaires. La forme préférée est le soufre alpha Sa, de formule Sx correspondant au cyclooctasoufre, qui est la forme thermodynamiquement la plus stable. De préférence, la cathode ne contient pas de sulfure de métaux de transition tels que TiS2, TiSs, TiS4, NiS, N1S2, CuS, FeS2, et M0S3. Selon un mode de réalisation, elle ne contient pas Li2S lors du montage de l’élément. De préférence, la cathode ne contient pas d’autres espèces électrochimiquement actives que le soufre élémentaire et le cuivre introduit sous les formes présentées ci-avant. Elemental solid sulfur exists in different molecular forms. The preferred form is sulfur alpha Sa, of formula Sx corresponding to cyclooctasulfur, which is the thermodynamically most stable form. Preferably, the cathode does not contain transition metal sulfides such as TiS2, TiSs, TiS4, NiS, N1S2, CuS, FeS2, and MOS3. According to one embodiment, it does not contain Li2S when mounting the element. Preferably, the cathode contains no other electrochemically active species than elemental sulfur and copper introduced in the forms presented above.
[0038] Le carbone utilisé dans le composite présente une structure poreuse. Il peut présenter une mésoporosité, c’est-à-dire des pores ayant un diamètre moyen supérieur à 2 nm et inférieur à 50 nm ou présenter une microporosité, c’est-à-dire des pores ayant un diamètre moyen inférieur à 2 nm. Le diamètre moyen des pores peut être compris entre 0,5 et 2 nm. Les pores de la structure poreuse logent les particules de soufre élémentaire. The carbon used in the composite has a porous structure. It can have mesoporosity, i.e. pores having an average diameter greater than 2 nm and less than 50 nm or have microporosity, i.e. pores having an average diameter less than 2 nm . The average pore diameter can be between 0.5 and 2 nm. The pores of the porous structure house the elemental sulfur particles.
L’électrolyte solide (7) de la cathode est un composé conducteur ionique, principalement conducteur des ions Lit II est de préférence un composé inorganique soufré pouvant être choisi parmi : The solid electrolyte (7) of the cathode is an ionically conductive compound, mainly conductive of Lit II ions is preferably an inorganic sulfur compound which can be chosen from:
- un composé de formule LixPSy où 1,4 <x < 1,6 et 3 <y < 3,5, susceptible d’être obtenu à partir des précurseurs Li2S et P2S5. Un composé préféré est Lii;5PS3,3. Une composition typique de précurseur comprend 60% en mole de Li2S et 40% en mole de P2S5 ; - a compound of formula Li x PS y where 1.4<x<1.6 and 3<y<3.5, capable of being obtained from the precursors Li2S and P2S5. A preferred compound is Lii ; 5PS3.3. A typical precursor composition comprises 60 mole % Li2S and 40 mole % P2S5;
- un composé de formule (l-y)Li3PS4.yLiX où X désigne un atome d’halogène (y étant compris entre 0,05 et 0,40) ; - a compound of formula (l-y)Li3PS4.yLiX where X denotes a halogen atom (y being between 0.05 and 0.40);
- un composé de formule (Li2S)a(P2S5)b(LiX)c(Li2O)d avec a+b+c+d=l ; - a compound of formula (Li2S) a (P2S5)b(LiX) c (Li2O)d with a+b+c+d=1;
- un composé de formule LiePSsX de type argyrodite où X désigne un atome d’halogène, susceptible d’être obtenu à partir des précurseurs Li2S, P2S5 et LiX, par exemple LiePSsI ou Li6PS5Cl ; - a compound of formula LiePSsX of argyrodite type where X denotes a halogen atom, capable of being obtained from the precursors Li2S, P2S5 and LiX, for example LiePSsI or Li 6 PS 5 Cl;
- un mélange de LiePSsX avec une solution solide de LiX-LiBFL où X est un halogène,- a mixture of LiePSsX with a solid solution of LiX-LiBFL where X is a halogen,
- un composé argyrodite éventuellement substitué par du borohydrure, ayant pour formule Li7-xPS6-xXx-z(BH4)z dans laquelle X est choisi dans le groupe consistant en Cl, Br, I, F et CN ; 0<x<2 et 0<z<0,50. x peut être égal à 1. X est de préférence I ou Cl ; 0,l<z<0,35 ou- an argyrodite compound optionally substituted by borohydride, having the formula Li7-xPS6-xX x -z(BH4)z in which X is chosen from the group consisting of Cl, Br, I, F and CN; 0<x<2 and 0<z<0.50. x can be equal to 1. X is preferably I or Cl; 0.1<z<0.35 or
0,l<z<0,20 ou encore 0,15<z<0,20. Ce composé peut être choisi parmi
0.1<z<0.20 or even 0.15<z<0.20. This compound can be chosen from
- un composé issu du mélange de Li2S/P2S/LiCl/LiBr/LiX, X désigne un ou plusieurs
atomes d’halogène parmi Cl, Br et I et suivi d’un traitement, par exemple préparé par broyage mécanique suivi d’un traitement thermique. - a compound resulting from the mixture of Li2S/P2S/LiCl/LiBr/LiX, X denotes one or more halogen atoms from Cl, Br and I and followed by a treatment, for example prepared by mechanical grinding followed by a heat treatment.
[0039] Le liant peut être choisi parmi le polyfluorure de vinylidène (PVDF) et ses copolymères, polytétrafluoroéthylène (PTFE) et ses copolymères, polyacrylonitrile (PAN), poly(méthyl)- ou (butyl)méthacrylate, polychlorure de vinyle (PVC), poly(vinyl formai), polyester, po- lyétheramides séquencés, polymères d'acide acrylique, acide méthacrylique, acrylamide, acide itaconique, acide sulfonique, élastomère et les composés cellulosiques. Le ou les élastomères pouvant être utilisés comme liant peuvent être choisis parmi le styrène-buta- diène (SBR), le butadiène-acrylonitrile (NBR), le butadiène-acrylonitrile hydrogéné (HNBR), et un mélange de plusieurs de ceux-ci. The binder can be chosen from polyvinylidene fluoride (PVDF) and its copolymers, polytetrafluoroethylene (PTFE) and its copolymers, polyacrylonitrile (PAN), poly(methyl)- or (butyl)methacrylate, polyvinyl chloride (PVC) , poly(vinyl formal), polyester, block polyetheramides, polymers of acrylic acid, methacrylic acid, acrylamide, itaconic acid, sulfonic acid, elastomer and cellulosic compounds. The elastomer or elastomers that can be used as binder can be chosen from styrene-butadiene (SBR), butadiene-acrylonitrile (NBR), hydrogenated butadiene-acrylonitrile (HNBR), and a mixture of several of these.
[0040] Le composé conducteur électronique est généralement du noir de carbone. [0040] The electronically conductive compound is generally carbon black.
[0041] Un procédé possible pour la préparation de la composition de matière active cathodique est le suivant : A possible process for the preparation of the composition of cathodic active material is as follows:
[0042] Dans une première étape, on synthétise l’électrolyte solide de la cathode par mécanosyn- thèse, c’est-à-dire un broyage mécano-chimique à haute énergie, en broyant un mélange des précurseurs de l’électrolyte solide. Par exemple, le broyage mécano-chimique à haute énergie des précurseurs Li2S et P2S5 conduit au composé de formule LixPSy où 1,4 <x < 1,6 et 3 <y < 3,5. L’électrolyte solide est obtenu sous la forme d’une poudre. [0042] In a first step, the solid electrolyte of the cathode is synthesized by mechanosynthesis, that is to say high-energy mechanical-chemical grinding, by grinding a mixture of precursors of the solid electrolyte. For example, the high-energy mechanical-chemical grinding of the Li2S and P2S5 precursors leads to the compound of formula Li x PS y where 1.4<x<1.6 and 3<y<3.5. The solid electrolyte is obtained in the form of a powder.
[0043] Dans une seconde étape, on prépare une poudre d’un mélange comprenant un composite de soufre solide élémentaire et de carbone et généralement un ou plusieurs liant(s) et au moins un composé conducteur électronique. In a second step, a powder is prepared from a mixture comprising a composite of elemental solid sulfur and carbon and generally one or more binder(s) and at least one electronically conductive compound.
[0044] On incorpore les particules de soufre élémentaire dans les pores de la structure poreuse du carbone. Pour ce faire, on mélange le carbone poreux avec le soufre élémentaire solide. Typiquement, la masse de soufre élémentaire solide représente de 30 à 90% ou de 55 à 65% de la somme des masses de soufre élémentaire solide et de carbone. La masse de carbone représente typiquement de 70 à 10% ou de 45 à 35% de la somme des masses de soufre élémentaire solide et de carbone. Le mélange est de préférence chauffé à une température voisine de 155°C pendant environ 5 heures, sous vide, pour permettre aux molécules de soufre de pénétrer dans les pores ouverts du carbone. Au voisinage de 155°C, le soufre à l’état liquide présente sa viscosité la plus faible. Le mélange est ensuite chauffé sous gaz inerte à une température comprise entre 200°C et 350°C pendant environ 30 minutes, ce qui a pour effet de sublimer le soufre et d’en éliminer l’excès. Le produit obtenu est ensuite généralement mélangé à au moins un liant et au moins un composé bon conducteur électronique. On obtient une poudre comprenant le composite S-C. [0044] The particles of elemental sulfur are incorporated into the pores of the porous structure of the carbon. This is done by mixing porous carbon with solid elemental sulfur. Typically, the mass of solid elemental sulfur is 30-90% or 55-65% of the sum of the masses of solid elemental sulfur and carbon. The mass of carbon is typically 70 to 10% or 45 to 35% of the sum of the masses of solid elemental sulfur and carbon. The mixture is preferably heated to a temperature close to 155° C. for about 5 hours, under vacuum, to allow the sulfur molecules to penetrate into the open pores of the carbon. Around 155°C, sulfur in the liquid state has its lowest viscosity. The mixture is then heated under inert gas at a temperature between 200°C and 350°C for about 30 minutes, which has the effect of sublimating the sulfur and eliminating the excess. The product obtained is then generally mixed with at least one binder and at least one good electronic conductor compound. A powder comprising the composite S-C is obtained.
[0045] On mélange la poudre d’électrolyte solide à la poudre comprenant le composite S-C par exemple à l’aide d’un broyeur planétaire. Le mélange peut par exemple comprendre de 30% à 60%, de préférence environ 50% en masse de la poudre d’électrolyte solide et de 70% à 40%, de préférence environ 50% en masse de la poudre comprenant le composite S- C. Une composition de matière active cathodique est ainsi obtenue. En plaçant cette composition dans un moule à pastiller et en appliquant sur cette composition une force de compression de l’ordre de plusieurs tonnes par cm2, il est possible de rendre cette composition
compacte et de lui donner une forme de pastille, plus aisément manipulable qu’une composition sous forme de poudre. The solid electrolyte powder is mixed with the powder comprising the SC composite, for example using a planetary grinder. The mixture may for example comprise from 30% to 60%, preferably approximately 50% by mass of the solid electrolyte powder and from 70% to 40%, preferably approximately 50% by mass of the powder comprising the composite S- C. A composition of cathodic active material is thus obtained. By placing this composition in a tablet mold and by applying to this composition a compression force of the order of several tons per cm 2 , it is possible to make this composition compact and to give it the form of a pellet, which is easier to handle than a composition in powder form.
Anode Anode
[0046] L’anode peut être constituée de lithium ou d’un alliage à base de lithium et d’un élément chimique choisi parmi Mg, Al, B, Zn, Ag, Si, Sn, In et C, de préférence In. L’anode peut aussi être constituée d’une couche de lithium métal sur laquelle est déposée une couche d’indium, la couche d’indium étant au contact de la couche d’électrolyte solide. Ces deux couches forment un alliage de lithium et d’indium. Un collecteur de courant, par exemple en cuivre, peut être accolé à la couche de lithium métal ou de l’alliage de lithium. La figure 1 représente une anode (2) comprenant une couche constituée de lithium ou d’un alliage de lithium et d’indium (8) accolée à un collecteur de courant (9). L’anode peut aussi n’être constituée que d’un feuillard de lithium. The anode may consist of lithium or of an alloy based on lithium and a chemical element chosen from among Mg, Al, B, Zn, Ag, Si, Sn, In and C, preferably In. The anode may also consist of a layer of lithium metal on which is deposited an indium layer, the indium layer being in contact with the solid electrolyte layer. These two layers form an alloy of lithium and indium. A current collector, for example made of copper, can be attached to the layer of lithium metal or of the lithium alloy. FIG. 1 represents an anode (2) comprising a layer made up of lithium or of an alloy of lithium and indium (8) joined to a current collector (9). The anode can also consist only of a sheet of lithium.
Electrolyte solide entre l’anode et la cathode Solid electrolyte between anode and cathode
[0047] L’électrolyte solide (10) destiné à séparer l’anode de la cathode peut être identique ou différent de celui utilisé dans la fabrication de la composition de matière active cathodique. Il joue le rôle de séparateur entre l’anode et la cathode, empêchant la mise en contact de l’anode avec la cathode mais permettant néanmoins le transport des ions l.i . Son épaisseur peut varier entre 10 pm et 1 mm. De préférence, l’épaisseur du séparateur est inférieure ou égale à 100 pm. De préférence encore, elle va de 10 pm à 50 pm. Une épaisseur supérieure à 100 pm peut pénaliser la capacité massique de l’élément. The solid electrolyte (10) intended to separate the anode from the cathode can be identical to or different from that used in the manufacture of the composition of cathodic active material. It acts as a separator between the anode and the cathode, preventing the anode from coming into contact with the cathode but nevertheless allowing the transport of the l.i ions. Its thickness can vary between 10 μm and 1 mm. Preferably, the thickness of the separator is less than or equal to 100 μm. More preferably, it ranges from 10 μm to 50 μm. A thickness greater than 100 μm can penalize the mass capacity of the element.
Procédé de fabrication de l’élément Element manufacturing process
[0048] La composition de matière active cathodique est déposée sur un collecteur de courant, de préférence en cuivre, et l’ensemble est comprimé à une pression de l’ordre de plusieurs tonnes par cm2, ce qui permet à la composition de matière active cathodique d’adhérer au collecteur de courant. The cathode active material composition is deposited on a current collector, preferably made of copper, and the assembly is compressed to a pressure of the order of several tons per cm 2 , which allows the material composition active cathode from adhering to the current collector.
[0049] On peut aussi - avant de mettre la poudre de composition de matière active cathodique en contact avec le collecteur de courant - mettre cette poudre en contact avec une poudre de l’électrolyte solide destiné à séparer l’anode de la cathode, puis compacter les deux poudres par compression. On obtient alors une pastille constituée de l’accolement de la composition de matière active cathodique avec l’électrolyte solide. Puis on fixe par compression le collecteur de courant de la cathode sur une face de la pastille constituée de la composition de matière active cathodique. It is also possible - before putting the powder of cathodic active material composition in contact with the current collector - to put this powder in contact with a powder of the solid electrolyte intended to separate the anode from the cathode, then compact the two powders by compression. A pellet is then obtained consisting of the joining of the composition of cathodic active material with the solid electrolyte. Then the current collector of the cathode is fixed by compression on one face of the pellet made of the composition of cathodic active material.
[0050] Enfin, on accole une anode sur la surface libre de la pastille constituée de la poudre d’électrolyte solide. L’anode est fixée par compression. Il n’est pas nécessaire d’intercaler un séparateur entre l’anode et la cathode car l’électrolyte solide remplit ce rôle. Finally, an anode is attached to the free surface of the pellet consisting of the solid electrolyte powder. The anode is fixed by compression. It is not necessary to insert a separator between the anode and the cathode because the solid electrolyte fulfills this role.
[0051] Dans le cas où l’apport de cuivre à la cathode est réalisé par l’emploi d’un collecteur de courant en cuivre, les étapes essentielles du procédé de fabrication d’un élément selon l’invention sont les suivantes : a) mise à disposition d’une première poudre d’un électrolyte solide, b) mise à disposition d’une seconde poudre d’un composite carbone-soufre, laquelle poudre comprend éventuellement un conducteur électronique et un ou plusieurs liants,
c) mélange de la première poudre avec la seconde poudre pour obtenir une composition de matière active cathodique, e) compression de la composition de matière active cathodique, f) mise en contact de la composition de matière active cathodique comprimée avec un électrolyte solide, identique ou différent de l’électrolyte solide présent dans la composition de matière active cathodique et compression de l’ensemble obtenu, g) mise en contact de la composition de matière active cathodique obtenue à l’étape f) avec un feuillard de cuivre ou constitué d’un alliage à base de cuivre ou constitué d’un métal autre que le cuivre, le métal étant au moins partiellement recouvert d’un revêtement de cuivre ou d’un alliage à base de cuivre, puis compression de l’ensemble obtenu, h) mise en contact d’une surface libre de l’ensemble obtenu à l’étape g) avec une anode en lithium métal ou en alliage à base de lithium, i) compression de l’ensemble obtenu à l’étape h). In the case where the supply of copper to the cathode is carried out by the use of a copper current collector, the essential steps of the method for manufacturing an element according to the invention are as follows: a ) provision of a first powder of a solid electrolyte, b) provision of a second powder of a carbon-sulfur composite, which powder optionally comprises an electronic conductor and one or more binders, c) mixing the first powder with the second powder to obtain a cathodic active material composition, e) compressing the cathodic active material composition, f) bringing the compressed cathodic active material composition into contact with a solid electrolyte, identical or different from the solid electrolyte present in the composition of cathodic active material and compression of the assembly obtained, g) bringing the composition of cathodic active material obtained in step f) into contact with a sheet of copper or consisting of an alloy based on copper or consisting of a metal other than copper, the metal being at least partially covered with a coating of copper or a copper-based alloy, then compression of the assembly obtained, h ) bringing a free surface of the assembly obtained in step g) into contact with a lithium metal or lithium-based alloy anode, i) compression of the assembly obtained in step h).
[0052] Selon une variante, la mise en place du feuillard de la cathode à l’étape g) peut être effectuée avant l’étape f) de compression de la composition de matière active cathodique avec l’électrolyte solide. According to a variant, the positioning of the cathode strip in step g) can be carried out before step f) of compression of the composition of cathode active material with the solid electrolyte.
[0053] Dans le cas où l’apport de cuivre à la cathode est réalisé par l’ajout d’une poudre de cuivre métallique ou par l’emploi d’un composé à base de cuivre, les étapes essentielles du procédé de fabrication d’un élément selon l’invention sont les suivantes : a) mise à disposition d’une première poudre d’un électrolyte solide, b) mise à disposition d’une seconde poudre d’un composite carbone- soufre, laquelle poudre comprend éventuellement un conducteur électronique et un ou plusieurs liants, c) mise à disposition d’une troisième poudre constituée de cuivre ou d’un composé chimique contenant du cuivre, d) mélange des trois poudres pour obtenir une composition de matière active cathodique, e) compression de la composition de matière active cathodique, f) mise en contact de la composition de matière active cathodique comprimée avec un électrolyte solide, identique ou différent de l’électrolyte solide présent dans la composition de matière active cathodique et compression de l’ensemble obtenu, g) mise en contact de l’ensemble obtenu à l’étape f) avec un feuillard et compression de l’ensemble obtenu, h) mise en contact d’une surface libre de l’ensemble obtenu à l’étape g) avec une anode en lithium métal ou en alliage à base de lithium, i) compression de l’ensemble obtenu à l’étape h). In the case where the supply of copper to the cathode is carried out by the addition of a metallic copper powder or by the use of a copper-based compound, the essential steps of the manufacturing process of an element according to the invention are as follows: a) provision of a first powder of a solid electrolyte, b) provision of a second powder of a carbon-sulfur composite, which powder optionally comprises a electronic conductor and one or more binders, c) provision of a third powder consisting of copper or of a chemical compound containing copper, d) mixing of the three powders to obtain a composition of cathodic active material, e) compression of the cathodic active material composition, f) bringing the compressed cathodic active material composition into contact with a solid electrolyte, identical to or different from the solid electrolyte present in the cathodic active material composition and compressing the assembly o bheld, g) bringing the assembly obtained in step f) into contact with a strip and compressing the assembly obtained, h) bringing a free surface of the assembly obtained in step g) into contact with a lithium metal or lithium-based alloy anode, i) compression of the assembly obtained in step h).
[0054] Selon une variante, la mise en place du feuillard de l’étape g) peut être effectuée avant l’étape f) de compression de la composition de matière active cathodique avec l’électrolyte solide. According to a variant, the positioning of the strip of step g) can be carried out before step f) of compression of the composition of cathodic active material with the solid electrolyte.
[0055] La quantité de l’élément cuivre présent dans la cathode est inférieure ou égale à 0,37 gramme de cuivre par Ampère. heure chargé par l’élément. La quantité de cuivre par ampère heure chargé est connue de l’opérateur qui fabrique l’élément. En effet, d’une part, l’opérateur connaît la quantité de cuivre introduite dans l’élément, que le cuivre soit introduit sous forme d’un collecteur métallique ou d’une poudre de cuivre ou d’un composé
chimique contenant du cuivre. S’il est introduit sous forme d’un composé à base de cuivre, la connaissance de la masse molaire moléculaire de ce composé permet de connaître le nombre de mole du composé et d’en déduire la masse de cuivre équivalente. Le nombre d’ampère heure chargé peut être obtenu à partir de la connaissance de la masse de soufre utilisée dans l’élément et de la capacité théorique massique du soufre qui est de 1670 mAh par gramme de soufre. (Généralement, la capacité électrochimique du soufre élémentaire de la cathode est inférieure à celle du lithium de l’anode. La capacité du soufre élémentaire limite la capacité de l’élément). Le nombre d’ampère heure chargé peut aussi être déterminé en chargeant lentement l’élément à température ambiante, par exemple à un régime de C/50 ou plus lent, comme réalisé dans les exemples des figures 2 et 4. The quantity of the element copper present in the cathode is less than or equal to 0.37 grams of copper per ampere. time charged by the item. The quantity of copper per charged ampere hour is known to the operator who manufactures the element. Indeed, on the one hand, the operator knows the quantity of copper introduced into the element, whether the copper is introduced in the form of a metal collector or of a copper powder or of a compound chemical containing copper. If it is introduced in the form of a copper-based compound, knowing the molecular molar mass of this compound makes it possible to know the number of moles of the compound and to deduce the equivalent copper mass therefrom. The number of ampere hours charged can be obtained from knowledge of the mass of sulfur used in the element and the theoretical mass capacity of sulfur which is 1670 mAh per gram of sulfur. (Generally, the electrochemical capacity of elemental sulfur of the cathode is lower than that of lithium of the anode. The capacity of elemental sulfur limits the capacity of the element). The number of ampere-hours charged can also be determined by slowly charging the element at ambient temperature, for example at a rate of C/50 or slower, as carried out in the examples of figures 2 and 4.
[0056] Le rapport nCu/nLi doit être supérieur ou égal à 0,04 et inférieur à 0,81, préférentiellement inférieur à 0,5. Si la quantité de cuivre dans la cathode est supérieure à 0,37 g par ampère heure chargé par l’élément ou si le ratio nCu/nLi est supérieur ou égal à 0,81, la quantité d’ions Cu+ ou Cu2+ formés dans l’électrolyte lors de la charge sera trop importante et risque de migrer vers l’anode et s’y réduire en Cu métal. La formation de Cu métal au voisinage de l’anode pourrait conduire à la formation de dendrites de cuivre susceptibles d’être à l’origine d’un court-circuit interne entre l’anode et la cathode. Le nombre de mole de cuivre nCu peut être obtenu en divisant la masse de cuivre utilisée par la masse molaire du cuivre ou en divisant la masse du composé à base de cuivre utilisé par sa masse molaire moléculaire. Le nombre de mole de lithium nLi peut être calculé à partir de la connaissance de la masse du composé à base de lithium utilisé dans l’élément et de la masse molaire moléculaire de ce composé. The nCu/nLi ratio must be greater than or equal to 0.04 and less than 0.81, preferably less than 0.5. If the quantity of copper in the cathode is greater than 0.37 g per ampere hour charged by the element or if the nCu/nLi ratio is greater than or equal to 0.81, the quantity of Cu + or Cu 2+ ions formed in the electrolyte during charging will be too great and may migrate towards the anode and be reduced there to Cu metal. The formation of Cu metal in the vicinity of the anode could lead to the formation of copper dendrites liable to be the cause of an internal short circuit between the anode and the cathode. The number of moles of copper nCu can be obtained by dividing the mass of copper used by the molar mass of copper or by dividing the mass of the copper-based compound used by its molecular molar mass. The number of moles of lithium nLi can be calculated from knowledge of the mass of the lithium-based compound used in the element and the molecular molar mass of this compound.
[0057] L’élément électrochimique selon l’invention offre les avantages suivants : The electrochemical element according to the invention offers the following advantages:
- il présente une capacité gravimétrique élevée. On peut atteindre une capacité gravimé- trique d’au moins environ 2000 mAh par gramme de soufre dans le composite S-C pour une décharge à température ambiante, de préférence d’au moins environ 2500 mAh/g.- it has a high gravimetric capacity. A gravimetric capacity of at least about 2000 mAh per gram of sulfur in the S-C composite can be achieved for discharge at room temperature, preferably at least about 2500 mAh/g.
- il peut être cyclé pendant un nombre significatif de cycles en réduisant le risque de dendrites. En effet, le remplacement d’un électrolyte liquide par un électrolyte solide permet de réduire le risque d’apparition d’un court-circuit entre l’anode et la cathode. Des dendrites sont moins susceptibles de se former dans le cas d’un électrolyte solide que d’un électrolyte liquide. - it can be cycled for a significant number of cycles reducing the risk of dendrites. Indeed, the replacement of a liquid electrolyte by a solid electrolyte makes it possible to reduce the risk of the appearance of a short circuit between the anode and the cathode. Dendrites are less likely to form in the case of a solid electrolyte than a liquid electrolyte.
- il possède une bonne durée de vie en cyclage. - it has a good cycle life.
- le cuivre étant un élément bon conducteur électronique, il contribue à l’augmentation de la conductivité électronique de la cathode et permet une décharge de la cathode à des régimes de décharge plus élevés. - copper being a good electronic conductor element, it contributes to the increase of the electronic conductivity of the cathode and allows a discharge of the cathode at higher discharge rates.
[0058] L’élément électrochimique selon l’invention peut être avantageusement utilisé dans des domaines dans lesquels on recherche des éléments électrochimiques présentant une énergie spécifique supérieure à celle des éléments lithium-ion. On peut citer le domaine spatial (satellites) et le domaine aéronautique.
Exemples 1 à 3 The electrochemical element according to the invention can be advantageously used in fields in which electrochemical elements having a higher specific energy than that of lithium-ion elements are sought. Mention may be made of the space domain (satellites) and the aeronautical domain. Examples 1 to 3
[0059] Deux éléments électrochimiques différant par la nature du collecteur de courant de leur cathode ont été fabriqués. Leurs constituants sont décrits dans le tableau 1 ci-après. L’élément 1 selon l’invention diffère de l’élément 1 comparatif par la nature du feuillard de la cathode qui est en cuivre au lieu d’être en aluminium pour le feuillard de l’élément 1 comparatif. Two electrochemical elements differing in the nature of the current collector of their cathode have been manufactured. Their constituents are described in Table 1 below. Element 1 according to the invention differs from comparative element 1 by the nature of the strip of the cathode which is made of copper instead of aluminum for the strip of comparative element 1.
[Tableau 1]
[Table 1]
* Soufre solide élémentaire disponible auprès de la société Sigma-Aldrich, sous la référence 215198. * Elemental solid sulfur available from Sigma-Aldrich, under reference 215198.
** Noir de carbone ** Carbon Black
*** obtenu à partir d’un mélange de précurseur Li2S et P2S5 à un ratio molaire de 60:40 *** obtained from a mixture of precursor Li2S and P2S5 at a molar ratio of 60:40
**** obtenu en suivant la procédure décrite dans WO 2019/057840 **** obtained by following the procedure described in WO 2019/057840
[0060] Les éléments ont subi un cycle de charge-décharge. Les éléments ont été testés sous une pression de 100 MPa. La variation de la tension en fonction de la capacité chargée ou déchargée est représentée figure 2. On constate que les capacités chargées et déchargées de l’élément 1 selon l’invention comprenant un collecteur de courant en cuivre sont supérieures à celles de l’élément 1 comparatif comprenant un collecteur de courant en aluminium. La capacité en décharge de l’élément 1 selon l’invention est de 2500 mAh par gramme de soufre dans le composite S-C, alors que celle de l’élément 1 comparatif n’est que d’environ 1350 mAh par gramme de soufre dans le composite S-C. Ceci représente une augmentation significative de la capacité d’environ 85%. The elements have undergone a charge-discharge cycle. The elements have been tested under a pressure of 100 MPa. The variation of the voltage as a function of the charged or discharged capacitance is represented in FIG. 2. It can be seen that the charged and discharged capacitances of the element 1 according to the invention comprising a copper current collector are greater than those of the element 1 comparative comprising an aluminum current collector. The discharge capacity of the element 1 according to the invention is 2500 mAh per gram of sulfur in the S-C composite, whereas that of the comparative element 1 is only about 1350 mAh per gram of sulfur in the S-C composite. This represents a significant capacity increase of approximately 85%.
[0061] La capacité obtenue est supérieure à la capacité théorique du soufre présent dans le composite carbone- soufre. La capacité supplémentaire observée est réversible car elle se maintient sur plusieurs cycles. La figure 3 représente la variation de la capacité de l’élément 1 selon l’invention par gramme de soufre dans le composite S-C en fonction du nombre de cycles effectués. La perte de capacité est d’environ 25% après 40 cycles. The capacity obtained is greater than the theoretical capacity of the sulfur present in the carbon-sulfur composite. The additional capacity observed is reversible because it is maintained over several cycles. Figure 3 represents the variation of the capacity of the element 1 according to the invention per gram of sulfur in the composite S-C according to the number of cycles carried out. Capacity loss is approximately 25% after 40 cycles.
[0062] Deux autres éléments ont été fabriqués. Leurs constituants sont décrits dans les tableaux 2 et 3 ci-après. Dans ces deux éléments, les pores du carbone poreux sont exempts de soufre élémentaire, de manière que la capacité déchargée mesurée ne puisse pas être attribuée à l’activité électrochimique du soufre élémentaire. L’élément 2 hors invention diffère de l’élément 2 comparatif par la nature du feuillard de la cathode qui est en cuivre au lieu d’être en aluminium pour le feuillard de l’élément 2 comparatif. Les courbes de variation
de la tension de ces deux éléments au cours des deux premiers cycles sont représentées en figure 4. [0062] Two other elements were manufactured. Their constituents are described in Tables 2 and 3 below. In both elements, the pores of the porous carbon are free of elemental sulfur, so that the measured discharged capacitance cannot be attributed to the electrochemical activity of elemental sulfur. Element 2 outside the invention differs from comparative element 2 by the nature of the strip of the cathode which is made of copper instead of aluminum for the strip of comparative element 2. Variation curves voltage of these two elements during the first two cycles are shown in Figure 4.
[Tableau 2]
[Table 2]
* disponible auprès de la société Akzo Nobel sous la dénomination commerciale « Ketjen Black® » ECP600J * available from Akzo Nobel under the trade name “Ketjen Black®” ECP600J
** obtenu à partir d’un mélange de précurseur I 2S et P2S5 à un ratio molaire 60:40. ** obtained from a mixture of precursor I 2S and P2S5 at a molar ratio of 60:40.
Tableau 3]
[0063] Les éléments étant assemblés à l’état chargé, la première phase de cyclage est une phase de décharge. On constate qu’ après la phase initiale de décharge (dchi sur la figure 4), les deux éléments présentent des capacités déchargées voisines (0,31 mAh pour l’élément 2 hors invention et 0,40 mAh pour l’élément 2 comparatif). Table 3] The elements being assembled in the charged state, the first cycling phase is a discharge phase. It can be seen that after the initial phase of discharge (dchi in FIG. 4), the two elements have similar discharged capacities (0.31 mAh for element 2 outside the invention and 0.40 mAh for comparative element 2) .
[0064] Au cours de la charge (chi) suivant la décharge initiale, la capacité chargée de l’élément 2 hors invention est de 3,5 mAh. Celle de l’élément 2 comparatif n’est que de 0,39 mAh. Au cours de la seconde décharge (dch2), la capacité de l’élément 2 hors invention est de 3,2 mAh. Celle de l’élément 2 comparatif n’est que de 0,45 mAh. Ces résultats confirment l’existence d’une interaction entre le cuivre de la cathode et les autres constituants de la cathode. During the charge (chi) following the initial discharge, the charged capacity of element 2 outside the invention is 3.5 mAh. That of the comparative element 2 is only 0.39 mAh. During the second discharge (dch2), the capacity of element 2 outside the invention is 3.2 mAh. That of the comparative element 2 is only 0.45 mAh. These results confirm the existence of an interaction between the copper of the cathode and the other constituents of the cathode.
[0065] Deux autres éléments ont été fabriqués. Leurs constituants sont décrits dans le tableau 4 ci- dessous. L’élément 3 selon l’invention diffère de l’élément 3 comparatif par la nature du feuillard de la cathode qui est en cuivre au lieu d’être en aluminium pour le feuillard de l’élément comparatif 3. [0065] Two other elements were manufactured. Their constituents are described in Table 4 below. Element 3 according to the invention differs from comparative element 3 by the nature of the strip of the cathode which is made of copper instead of being aluminum for the strip of comparative element 3.
[Tableau 4]
[Table 4]
* soufre solide élémentaire disponible auprès de la société Sigma-Aldrich, sous la référence 215198. * elemental solid sulfur available from Sigma-Aldrich, under reference 215198.
** noir de carbone ** carbon black
*** obtenu à partir d’un mélange de précurseur Li2S et P2S5 à un ratio molaire 60:40 *** obtained from a mixture of precursor Li2S and P2S5 at a molar ratio of 60:40
[0066] La figure 5 représente les courbes de tension en charge et en décharge de l’élément 3 comparatif et de l’élément 3 selon l’invention en fonction de la capacité déchargée (mAh). On constate que les capacités chargées et déchargées de l’élément 3 selon l’invention comprenant un collecteur de courant en cuivre sont supérieures à celles de l’élément 3 comparatif comprenant un collecteur de courant en aluminium. La capacité en décharge de l’élément 3 selon l’invention est de 2,5 mAh alors que celle de l’élément 3 comparatif n’est que d’environ 0,35 mAh par gramme de soufre dans le composite S-C, soit une multiplication par 7 de la capacité. FIG. 5 represents the charging and discharging voltage curves of the comparative element 3 and of the element 3 according to the invention as a function of the discharged capacity (mAh). It can be seen that the charged and discharged capacities of the element 3 according to the invention comprising a copper current collector are greater than those of the comparative element 3 comprising an aluminum current collector. The discharge capacity of the element 3 according to the invention is 2.5 mAh whereas that of the comparative element 3 is only about 0.35 mAh per gram of sulfur in the S-C composite, i.e. a multiplication by 7 of the capacity.
[0067] La figure 6 représente les courbes de tension en charge et en décharge de l’élément 3 selon l’invention aux cycles n°3, 4, 5 et 6 en fonction de la capacité de l’élément par gramme de soufre dans le composite S-C. La capacité déchargée est comprise entre 8000 et 9000 mAh par gramme de soufre dans le composite S-C.
[0068] La capacité déchargée par l’élément 3 comparatif est beaucoup plus faible comme le montre la figure 7 qui représente les courbes de tension en charge et en décharge de l’élément 3 comparatif aux cycles n°l et 8 en fonction de la capacité de l’élément par gramme de soufre dans le composite S-C. La capacité déchargée est seulement d’environ 1200 mAh par gramme de soufre dans le composite S-C. FIG. 6 represents the charging and discharging voltage curves of the element 3 according to the invention at cycles no. 3, 4, 5 and 6 as a function of the capacity of the element per gram of sulfur in the SC-composite. The discharged capacity is between 8000 and 9000 mAh per gram of sulfur in the SC composite. The capacitance discharged by comparative element 3 is much lower as shown in FIG. 7 which represents the charging and discharging voltage curves of comparative element 3 at cycles n° 1 and 8 as a function of the capacity of the element per gram of sulfur in the composite SC. The discharged capacity is only about 1200 mAh per gram of sulfur in the SC composite.
[0069] Autres exemples :
[0069] Other examples:
Tableau 5]
exemple comparatif * une masse de 2 mg correspond à une épaisseur de 25 pm. ne masse de 40 mg correspond à une épaisseur de 500 pm.
Table 5] comparative example * a mass of 2 mg corresponds to a thickness of 25 μm. a mass of 40 mg corresponds to a thickness of 500 μm.
Mesure des rapports nCu/nLi et mCu en g/Ah : Measurement of nCu/nLi and mCu ratios in g/Ah:
[0070] L’élément électrochimique est chargé à une tension de 2,7V. L’élément, composé d’une surface S d’électrode positive et négative, est démonté puis placé dans un conteneur étanche de volume connu (V) muni d’un septum et d’un capteur de pression et de température. Une quantité d’eau, mEEO, égale à 5 fois la masse de l’élément, est introduite dans le conteneur à l’aide d’une aiguille pour faire réagir la totalité du lithium métal qui est transformé en hydrogène. Le nombre de mole d’hydrogène formé peut être calculé à partir de la variation de pression, dP, le volume mort de la cellule, Vm, (correspondant au volume du conteneur corrigé du volume de l’élément analysé et du volume d’eau rajoutée) et la température du conteneur (T) ; nH2= dP*Vm/(R*T). La quantité de lithium à l’état réduit est égal à Nu réduit=nH2/2. The electrochemical element is charged to a voltage of 2.7V. The element, made up of a positive and negative electrode surface S, is disassembled and then placed in a sealed container of known volume (V) equipped with a septum and a pressure and temperature sensor. A quantity of water, mEEO, equal to 5 times the mass of the element, is introduced into the container using a needle to react all the lithium metal which is transformed into hydrogen. The number of moles of hydrogen formed can be calculated from the variation in pressure, dP, the dead volume of the cell, Vm, (corresponding to the volume of the container corrected for the volume of the element analyzed and the volume of water added) and container temperature (T); nH2= dP*Vm/(R*T). The quantity of lithium in the reduced state is equal to Nu reduced=nH2/2.
Le conteneur est ensuite ouvert, puis le collecteur de l’électrode négative est extrait avant de réaliser les étapes suivantes. Le reste de l’élément est ensuite placé dans un bêcher. Une solution de KMnCU à 1 mole/L est ensuite rajoutée dans le conteneur de manière à oxyder les ions sulfures de l’électrolyte, soit VK le volume de cette solution. Cette étape permet alors d’attaquer la totalité de l’élément par une solution d’acide concentrée ayant pour effet de dissoudre tous les constituants tout en évitant la formation d’ FUS, soit Vac le volume d’acide permettant d’atteindre un pH de la solution après attaque égal à 1. Les concentrations de lithium Cu et de cuivre Ccu peuvent ensuite être mesurée par ICP Le nombre de mole total de lithium NLitotai= CLi*(Veau+VK+Vac) et Ncu = Ccu*(Veau+VK+Vac) ; The container is then opened, then the collector of the negative electrode is extracted before carrying out the following steps. The rest of the element is then placed in a beaker. A solution of KMnCU at 1 mol/L is then added to the container so as to oxidize the sulphide ions of the electrolyte, giving VK the volume of this solution. This step then makes it possible to attack the entire element with a concentrated acid solution having the effect of dissolving all the constituents while avoiding the formation of FUS, i.e. V ac the volume of acid making it possible to reach a pH of the solution after etching equal to 1. The concentrations of lithium Cu and copper Cc u can then be measured by ICP The total number of moles of lithium NLitotai= CLi*(V water +VK+V ac ) and Ncu = Ccu *(V water +VK+V ac );
Le nombre de mole de lithium de l’électrolyte est égal au nombre de mole total de Li soustrait du nombre de mole de lithium à l’état réduit : Nu= (Nu total - Nu réduit) ; The number of moles of lithium in the electrolyte is equal to the number of total moles of Li subtracted from the number of moles of lithium in the reduced state: Nu= (total Nu - reduced Nu);
Le rapport nCu/nLi de l’électrolyte est égal au rapport des grandeurs Ncu et Nu précédemment calculées divisées par la surface S d’électrode. The nCu/nLi ratio of the electrolyte is equal to the ratio of the quantities Ncu and Nu previously calculated divided by the surface area S of the electrode.
[0071] Les exemples du Tableau 5 permettent de tirer les enseignements suivants : The examples in Table 5 allow the following lessons to be drawn:
- L’élément de l’exemple 1 diffère de l’exemple de référence en ce qu’il contient du cuivre dans sa cathode. La capacité volumique passe de 3000 mAh/cc (Cu+S) pour l’élément de l’exemple de référence à 3106 mAh/cc (Cu+S) pour l’élément de l’exemple 1. De plus, il ne présente pas de court-circuit. - The element in example 1 differs from the reference example in that it contains copper in its cathode. The volume capacity changes from 3000 mAh/cc (Cu+S) for the element of the reference example to 3106 mAh/cc (Cu+S) for the element of example 1. no short circuit.
- Les éléments des exemples 9 à 15 sont comparatifs. Ils comportent une teneur élevée en cuivre et présentent des courts circuits. Ces éléments sont caractérisés soit par une masse de cuivre par Ah de soufre supérieure à 0,37 g/Ah (Exemples 9 à 14), soit par un ratio nCu/nLi supérieur à 0,81 (Exemple 15). - The elements of examples 9 to 15 are comparative. They have a high copper content and have short circuits. These elements are characterized either by a mass of copper per Ah of sulfur greater than 0.37 g/Ah (Examples 9 to 14), or by an nCu/nLi ratio greater than 0.81 (Example 15).
- Les éléments des exemples 3 et 4 contiennent 40 mg d’électrolyte solide entre l’anode et la cathode. Cette quantité élevée d’électrolyte solide pénalise fortement la capacité massique car celle-ci n’est que de 551 et de 452 mAh/g (Cu+S).
- The elements of examples 3 and 4 contain 40 mg of solid electrolyte between the anode and the cathode. This high quantity of solid electrolyte strongly penalizes the mass capacity because it is only 551 and 452 mAh/g (Cu+S).
Claims
[Revendication 1] Elément électrochimique lithium-soufre tout solide comprenant : a) au moins une cathode comprenant une composition de matière active cathodique comprenant : i) du soufre élémentaire, ii) du carbone, iii) un électrolyte solide, la cathode comprenant du cuivre, b) au moins une anode dont la matière active est du lithium ou un alliage à base de lithium, c) un électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode, identique ou différent de l’électrolyte solide présent dans la composition de matière active cathodique, la quantité de cuivre dans la cathode étant inférieure ou égale à 0,37 g par ampère heure chargé par l’élément, le rapport nCu/nLi dans l’élément à l’état chargé étant supérieur ou égal à 0,04 et inférieur à 0,81 où nCu désigne le nombre de mole de cuivre et nLi désigne la somme des nombres de mole de lithium dans l’électrolyte solide de la cathode et dans l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode. [Claim 1] An all-solid lithium-sulfur electrochemical cell comprising: a) at least one cathode comprising a cathodic active material composition comprising: i) elemental sulfur, ii) carbon, iii) a solid electrolyte, the cathode comprising copper , b) at least one anode whose active material is lithium or a lithium-based alloy, c) a solid electrolyte interposed between said at least one cathode and said at least one anode, identical to or different from the solid electrolyte present in the composition of cathode active material, the amount of copper in the cathode being less than or equal to 0.37 g per ampere hour charged by the element, the nCu/nLi ratio in the element in the charged state being greater than or equal to 0.04 and less than 0.81 where nCu denotes the number of moles of copper and nLi denotes the sum of the numbers of moles of lithium in the solid electrolyte of the cathode and in the solid electrolyte interposed between said at least a cathode and t said at least one anode.
[Revendication 2] Elément électrochimique selon la revendication 1, dans lequel le cuivre est présent sous l’une ou plusieurs des formes a, P et y suivantes : a) sous la forme d’un collecteur métallique servant de collecteur de courant de la cathode, le collecteur métallique étant constitué de cuivre ou d’un alliage à base de cuivre ou étant constitué d’un métal au moins partiellement recouvert d’un revêtement de cuivre ou d’un alliage à base de cuivre, [Claim 2] An electrochemical cell according to claim 1, wherein the copper is present in one or more of the following forms a, P and y: a) in the form of a metallic collector serving as the current collector of the cathode , the metal collector being made of copper or a copper-based alloy or being made of a metal at least partially covered with a coating of copper or a copper-based alloy,
P) sous la forme d’une poudre de cuivre incorporée à la composition de matière active cathodique, y) sous la forme d’un composé chimique contenant du cuivre incorporé à la composition de matière active cathodique. P) in the form of a copper powder incorporated into the composition of cathodic active material, y) in the form of a chemical compound containing copper incorporated into the composition of cathodic active material.
[Revendication 3] Elément électrochimique selon la revendication 1 ou 2, dans lequel l’électrolyte solide de la composition de matière active cathodique et/ou l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode est un composé soufré. [Claim 3] An electrochemical cell according to claim 1 or 2, wherein the solid electrolyte of the cathodic active material composition and/or the solid electrolyte interposed between said at least one cathode and said at least one anode is a sulfur compound .
[Revendication 4] Elément électrochimique selon l’une des revendications précédentes, dans lequel la quantité de cuivre présente dans la cathode est inférieure ou égale à 0,12 g par ampère heure chargé par l’élément, de préférence égale à 0,06 ± 0,03 g par ampère heure.
[Revendication 5] Elément électrochimique selon l’une des revendications précédentes, dans lequel le rapport nCu/nLi est inférieur à 0,[Claim 4] Electrochemical element according to one of the preceding claims, in which the quantity of copper present in the cathode is less than or equal to 0.12 g per ampere hour charged by the element, preferably equal to 0.06 ± 0.03 g per ampere hour. [Claim 5] Electrochemical cell according to one of the preceding claims, in which the nCu/nLi ratio is less than 0,
5, de préférence inférieur à 0,3.5, preferably less than 0.3.
[Revendication 6] Elément électrochimique selon l’une des revendications précédentes, dans lequel l’électrolyte solide utilisé dans la cathode ou intercalé entre l’anode et la cathode lors de l’assemblage de l’élément est sous forme d’une poudre, la poudre étant recouverte de cuivre ou d’un composé contenant du cuivre.[Claim 6] Electrochemical element according to one of the preceding claims, in which the solid electrolyte used in the cathode or interposed between the anode and the cathode during assembly of the element is in the form of a powder, the powder being coated with copper or a compound containing copper.
[Revendication 7] Elément électrochimique lithium-soufre tout solide selon l’une des revendications précédentes, dans lequel l’électrolyte solide de la composition de matière active cathodique et l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode sont choisis dans le groupe consistant en : [Claim 7] All-solid lithium-sulfur electrochemical cell according to one of the preceding claims, in which the solid electrolyte of the cathode active material composition and the solid electrolyte interposed between the said at least one cathode and the said at least one anode are selected from the group consisting of:
- LixPSy où 1,4 <x < 1,6 et 3 <y < 3,5, susceptible d’être obtenu à partir des précurseurs Li2S et P2S5, - Li x PSy where 1.4 <x < 1.6 and 3 <y < 3.5, likely to be obtained from Li2S and P2S5 precursors,
- un composé de formule (l-y)Li3PS4.yLiX où X désigne un atome d’halogène avec 0,05 < y < 0,40, - a compound of formula (l-y)Li3PS4.yLiX where X denotes a halogen atom with 0.05 < y < 0.40,
- un composé de formule (Li2S)a(P2S5)b(LiX)c(Li2O)d avec a+b+c+d=l,- a compound of formula (Li2S)a(P2S5)b(LiX) c (Li2O)d with a+b+c+d=l,
- LiePSsX où X désigne un atome d’halogène, susceptible d’être obtenu à partir des précurseurs Li2S, P2S5 et LiX, - LiePSsX where X denotes a halogen atom, which can be obtained from the precursors Li2S, P2S5 and LiX,
- un mélange de LiePSsX avec une solution solide de LiX-LiBEU où X est un halogène, - a mixture of LiePSsX with a solid solution of LiX-LiBEU where X is a halogen,
- un composé argyrodite éventuellement substitué par du borohydrure, ayant pour formule Li7-xPS6-xXx-z(BH4)z dans laquelle X est choisi dans le groupe consistant en Cl, Br, I, F et CN ; 0<x<2 et 0<z<0,50, et - an argyrodite compound optionally substituted by borohydride, having the formula Li7-xPS6-xX x -z(BH4)z in which X is chosen from the group consisting of Cl, Br, I, F and CN; 0<x<2 and 0<z<0.50, and
- un mélange des composés Li2S/P2S/LiCl/LiBr/LiX, X désigne un ou plusieurs atomes d’halogène parmi Cl, Br et I après traitement thermique du mélange. - a mixture of Li2S/P2S/LiCl/LiBr/LiX compounds, X denotes one or more halogen atoms from Cl, Br and I after heat treatment of the mixture.
[Revendication 8] Elément électrochimique lithium-soufre tout solide selon la revendication 7, dans lequel l’électrolyte solide a pour formule Li7-xPS6-xXx-z(BH4)z dans laquelle X est I ; x=l et 0,l<z<0,35. [Claim 8] An all-solid lithium-sulfur electrochemical cell according to claim 7, wherein the solid electrolyte has the formula Li7-xPS6-xXx-z(BH4) z wherein X is I; x=1 and 0.1<z<0.35.
[Revendication 9] Elément électrochimique lithium-soufre tout solide selon la revendication 7, dans lequel l’électrolyte solide est choisi parmi LiePSsI, LiePSsCl,
[Claim 9] All-solid lithium-sulfur electrochemical cell according to claim 7, in which the solid electrolyte is selected from among LiePSsI, LiePSsCl,
[Revendication 10] Elément électrochimique selon l’une des revendications précédentes, dans lequel : [Claim 10] Electrochemical cell according to one of the preceding claims, in which:
- l’électrolyte solide de la composition de matière active cathodique a pour formule LixPSy où 1,4 <x < 1,6 et 3 <y < 3,5 et - the solid electrolyte of the cathodic active material composition has the formula Li x PS y where 1.4 <x <1.6 and 3 <y <3.5 and
- l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode est choisi parmi : - the solid electrolyte interposed between said at least one cathode and said at least one anode is chosen from:
- un composé de formule Li7-xPS6-xXx-z(BH4)z dans lequel X est choisi dans le
groupe consistant en Cl, Br, I, F et CN ; 0<x<2 et 0<z<0,50, et- a compound of formula Li7-xPS6-xXx-z(BH4) z in which X is chosen from the group consisting of Cl, Br, I, F and CN; 0<x<2 and 0<z<0.50, and
- un mélange des composés Li2S/P2S/LiCl/LiBr/LiX, X désigne un ou plusieurs atomes d’halogène parmi Cl, Br et I suivi d’un traitement thermique du mélange. - a mixture of Li2S/P2S/LiCl/LiBr/LiX compounds, X denotes one or more halogen atoms from Cl, Br and I followed by heat treatment of the mixture.
[Revendication 11] Elément électrochimique selon la revendication 10, dans lequel l’électrolyte solide intercalé entre ladite au moins une cathode et ladite au moins une anode a pour formule LiePSsE/e BEL^i/e. [Claim 11] Electrochemical element according to claim 10, in which the solid electrolyte interposed between the said at least one cathode and the said at least one anode has the formula LiePSsE/e BEL^i/e.
[Revendication 12] Elément électrochimique lithium-soufre tout solide selon l’une des revendications précédentes, dans lequel l’alliage est un alliage de lithium et d’un ou plusieurs éléments chimiques choisis dans le groupe consistant en l’indium, le silicium, l’étain et le carbone.
[Claim 12] All-solid lithium-sulfur electrochemical cell according to one of the preceding claims, in which the alloy is an alloy of lithium and one or more chemical elements selected from the group consisting of indium, silicon, tin and carbon.
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FR2013730A FR3118308B1 (en) | 2020-12-18 | 2020-12-18 | ALL-SOLID LITHIUM-SULFUR ELECTROCHEMICAL ELEMENT |
PCT/EP2021/084367 WO2022128566A1 (en) | 2020-12-18 | 2021-12-06 | All-solid-state lithium-sulphur electrochemical element |
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JPS5922739A (en) | 1982-07-30 | 1984-02-06 | Mitsubishi Heavy Ind Ltd | Tyre vulcanizer |
CN105308774B (en) | 2013-06-21 | 2018-01-30 | 长濑化成株式会社 | Anode mixture and all solid state type lithium-sulfur cell |
JP6716324B2 (en) * | 2016-04-05 | 2020-07-01 | 三菱瓦斯化学株式会社 | Electrode active material, electrode layer containing the same, and all-solid-state battery |
FR3071656B1 (en) | 2017-09-22 | 2019-10-11 | Universite Paris-Est Creteil Val De Marne (Upec) | SOLID ELECTROLYTE FOR LITHIUM-ION ELECTROCHEMICAL ELEMENT |
US10930972B2 (en) * | 2019-01-25 | 2021-02-23 | Toyota Motor Engineering & Manufacturing North America, Inc. | Metal-phosphorous sulfide additives for solid state batteries |
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