CN117410463A - Composite positive electrode material for sulfide solid-state battery, and preparation method and application thereof - Google Patents
Composite positive electrode material for sulfide solid-state battery, and preparation method and application thereof Download PDFInfo
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- CN117410463A CN117410463A CN202311347428.9A CN202311347428A CN117410463A CN 117410463 A CN117410463 A CN 117410463A CN 202311347428 A CN202311347428 A CN 202311347428A CN 117410463 A CN117410463 A CN 117410463A
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- sulfide
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- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 title claims abstract description 243
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 218
- 239000002131 composite material Substances 0.000 title claims abstract description 160
- 238000002360 preparation method Methods 0.000 title abstract description 13
- 239000003792 electrolyte Substances 0.000 claims abstract description 134
- 239000011259 mixed solution Substances 0.000 claims abstract description 80
- 239000002243 precursor Substances 0.000 claims abstract description 64
- 238000011065 in-situ storage Methods 0.000 claims abstract description 56
- 239000006258 conductive agent Substances 0.000 claims abstract description 53
- 238000000034 method Methods 0.000 claims abstract description 48
- 230000005540 biological transmission Effects 0.000 claims abstract description 43
- 150000002500 ions Chemical class 0.000 claims abstract description 36
- 238000001308 synthesis method Methods 0.000 claims abstract description 31
- 239000007787 solid Substances 0.000 claims abstract description 30
- 238000003756 stirring Methods 0.000 claims abstract description 18
- 238000001291 vacuum drying Methods 0.000 claims abstract description 15
- 230000000269 nucleophilic effect Effects 0.000 claims abstract description 12
- 150000001412 amines Chemical class 0.000 claims abstract description 9
- LSDPWZHWYPCBBB-UHFFFAOYSA-N Methanethiol Chemical compound SC LSDPWZHWYPCBBB-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000006183 anode active material Substances 0.000 claims abstract description 8
- 238000000227 grinding Methods 0.000 claims abstract description 8
- 239000002245 particle Substances 0.000 claims description 86
- 229910052744 lithium Inorganic materials 0.000 claims description 84
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical group [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 78
- 239000011572 manganese Substances 0.000 claims description 77
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 71
- 229910052748 manganese Inorganic materials 0.000 claims description 71
- 239000007788 liquid Substances 0.000 claims description 47
- 239000002134 carbon nanofiber Substances 0.000 claims description 33
- DNJIEGIFACGWOD-UHFFFAOYSA-N ethanethiol Chemical compound CCS DNJIEGIFACGWOD-UHFFFAOYSA-N 0.000 claims description 32
- 239000000203 mixture Substances 0.000 claims description 28
- 239000000843 powder Substances 0.000 claims description 27
- 239000000126 substance Substances 0.000 claims description 26
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 claims description 19
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 14
- 229910052717 sulfur Inorganic materials 0.000 claims description 13
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 12
- 239000013543 active substance Substances 0.000 claims description 12
- 239000011593 sulfur Substances 0.000 claims description 12
- 239000002203 sulfidic glass Substances 0.000 claims description 11
- 229910052759 nickel Inorganic materials 0.000 claims description 10
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 10
- 229910021389 graphene Inorganic materials 0.000 claims description 9
- 229910003002 lithium salt Inorganic materials 0.000 claims description 9
- 159000000002 lithium salts Chemical class 0.000 claims description 9
- RMVRSNDYEFQCLF-UHFFFAOYSA-N thiophenol Chemical compound SC1=CC=CC=C1 RMVRSNDYEFQCLF-UHFFFAOYSA-N 0.000 claims description 9
- SUVIGLJNEAMWEG-UHFFFAOYSA-N propane-1-thiol Chemical compound CCCS SUVIGLJNEAMWEG-UHFFFAOYSA-N 0.000 claims description 6
- WGYKZJWCGVVSQN-UHFFFAOYSA-N propylamine Chemical compound CCCN WGYKZJWCGVVSQN-UHFFFAOYSA-N 0.000 claims description 6
- -1 transition metal salt Chemical class 0.000 claims description 6
- HFCVPDYCRZVZDF-UHFFFAOYSA-N [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O Chemical compound [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O HFCVPDYCRZVZDF-UHFFFAOYSA-N 0.000 claims description 5
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 5
- 229910052723 transition metal Inorganic materials 0.000 claims description 5
- DHBXNPKRAUYBTH-UHFFFAOYSA-N 1,1-ethanedithiol Chemical compound CC(S)S DHBXNPKRAUYBTH-UHFFFAOYSA-N 0.000 claims description 4
- 239000002041 carbon nanotube Substances 0.000 claims description 4
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 4
- 238000009826 distribution Methods 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 4
- HQABUPZFAYXKJW-UHFFFAOYSA-N butan-1-amine Chemical compound CCCCN HQABUPZFAYXKJW-UHFFFAOYSA-N 0.000 claims description 3
- 229910052736 halogen Inorganic materials 0.000 claims description 3
- 150000002367 halogens Chemical class 0.000 claims description 3
- 150000003017 phosphorus Chemical class 0.000 claims description 2
- NCNISYUOWMIOPI-UHFFFAOYSA-N propane-1,1-dithiol Chemical compound CCC(S)S NCNISYUOWMIOPI-UHFFFAOYSA-N 0.000 claims description 2
- AOHJOMMDDJHIJH-UHFFFAOYSA-N propylenediamine Chemical compound CC(N)CN AOHJOMMDDJHIJH-UHFFFAOYSA-N 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 3
- 229910012820 LiCoO Inorganic materials 0.000 claims 1
- 239000000243 solution Substances 0.000 abstract description 34
- 238000010438 heat treatment Methods 0.000 abstract description 26
- 239000010405 anode material Substances 0.000 abstract description 8
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 abstract description 7
- 229910001416 lithium ion Inorganic materials 0.000 abstract description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 74
- 239000000463 material Substances 0.000 description 56
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 54
- 239000013078 crystal Substances 0.000 description 44
- 229910052786 argon Inorganic materials 0.000 description 37
- LHJOPRPDWDXEIY-UHFFFAOYSA-N indium lithium Chemical compound [Li].[In] LHJOPRPDWDXEIY-UHFFFAOYSA-N 0.000 description 14
- 229910000846 In alloy Inorganic materials 0.000 description 13
- 239000004570 mortar (masonry) Substances 0.000 description 13
- 239000007773 negative electrode material Substances 0.000 description 13
- 230000009471 action Effects 0.000 description 12
- 238000012360 testing method Methods 0.000 description 12
- 239000013590 bulk material Substances 0.000 description 11
- 229910018091 Li 2 S Inorganic materials 0.000 description 9
- 239000011248 coating agent Substances 0.000 description 9
- 238000000576 coating method Methods 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 7
- 230000001737 promoting effect Effects 0.000 description 7
- 238000010532 solid phase synthesis reaction Methods 0.000 description 7
- 230000032258 transport Effects 0.000 description 7
- 239000007791 liquid phase Substances 0.000 description 6
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 description 6
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 description 6
- 238000003760 magnetic stirring Methods 0.000 description 6
- 238000007086 side reaction Methods 0.000 description 6
- 239000006185 dispersion Substances 0.000 description 5
- 239000010406 cathode material Substances 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 239000011268 mixed slurry Substances 0.000 description 4
- 230000002194 synthesizing effect Effects 0.000 description 4
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 3
- 229910000572 Lithium Nickel Cobalt Manganese Oxide (NCM) Inorganic materials 0.000 description 3
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- FBDMTTNVIIVBKI-UHFFFAOYSA-N [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] Chemical compound [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] FBDMTTNVIIVBKI-UHFFFAOYSA-N 0.000 description 3
- 238000000498 ball milling Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 150000003573 thiols Chemical class 0.000 description 3
- QXZUUHYBWMWJHK-UHFFFAOYSA-N [Co].[Ni] Chemical compound [Co].[Ni] QXZUUHYBWMWJHK-UHFFFAOYSA-N 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 238000004146 energy storage Methods 0.000 description 2
- FKRCODPIKNYEAC-UHFFFAOYSA-N ethyl propionate Chemical compound CCOC(=O)CC FKRCODPIKNYEAC-UHFFFAOYSA-N 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- LBSANEJBGMCTBH-UHFFFAOYSA-N manganate Chemical compound [O-][Mn]([O-])(=O)=O LBSANEJBGMCTBH-UHFFFAOYSA-N 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 239000008247 solid mixture Substances 0.000 description 2
- 239000007790 solid phase Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 229910000299 transition metal carbonate Inorganic materials 0.000 description 2
- 229910000314 transition metal oxide Inorganic materials 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229910015872 LiNi0.8Co0.1Mn0.1O2 Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical class [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000010952 in-situ formation Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910052945 inorganic sulfide Inorganic materials 0.000 description 1
- 230000037427 ion transport Effects 0.000 description 1
- 239000011244 liquid electrolyte Substances 0.000 description 1
- 238000006138 lithiation reaction Methods 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000007344 nucleophilic reaction Methods 0.000 description 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 229910001251 solid state electrolyte alloy Inorganic materials 0.000 description 1
- 238000003836 solid-state method Methods 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 238000001947 vapour-phase growth Methods 0.000 description 1
- 229910001928 zirconium oxide 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
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/0402—Methods of deposition of the material
- H01M4/0416—Methods of deposition of the material involving impregnation with a solution, dispersion, paste or dry powder
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
-
- 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
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
-
- 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
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/581—Chalcogenides or intercalation compounds thereof
- H01M4/5815—Sulfides
-
- 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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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Composite Materials (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Dispersion Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
Abstract
The invention discloses a composite positive electrode material for a sulfide solid-state battery, and a preparation method and application thereof. The sulfide electrolyte precursor component is placed in the mixed solution of organic amine and organic mercaptan, and the sulfide electrolyte precursor component is completely dissolved in the mixed solution under the strong nucleophilic action force of the thioanion. The high specific capacity positive electrode active material and the conductive agent are added into the solution of the sulfide electrolyte precursor component, and the high interface stability between the high specific capacity positive electrode active material and the sulfide electrolyte is improved through heating and stirring and subsequent vacuum drying, roasting and grinding treatment, and a channel with a three-dimensional ion transmission network is constructed in the composite positive electrode material. The invention adopts the mixed solution synthesis method of organic amine and organic mercaptan to prepare the composite anode material in situ, the method obviously increases the solid-solid contact area of the anode active material and sulfide electrolyte, and promotes the efficient transmission of lithium ions in the composite anode.
Description
Technical Field
The invention relates to the technical field of solid-state battery electrode materials, in particular to a composite positive electrode material for a sulfide solid-state battery, a preparation method and application thereof.
Background
As an efficient and green energy storage and conversion device, lithium ion batteries are widely used in the fields of electronic products, electric automobiles, large-scale energy storage and the like. In recent years, with the increase in the demands for indexes such as energy density and safety, it has been difficult for liquid lithium ion batteries to meet the demands. For this reason, all-solid-state lithium battery technology based on different types of solid-state electrolytes has been developed and is expected to solve the above-described problems. Among them, the all-solid-state battery technology using an inorganic sulfide as a solid electrolyte has been receiving much attention and much research because sulfide electrolytes have not only ion conductivity comparable to that of liquid electrolytes but also advantages of low young's modulus, high thermal stability, mild synthesis conditions, and the like. Therefore, it is expected to combine sulfide electrolyte with positive electrode active material of high specific capacity and apply it to all-solid-state battery system, which can not only improve the energy density and safety of solid-state battery, but also realize tight contact between the inside of sulfide solid-state electrolyte and between positive electrode active material and sulfide electrolyte, helping to promote rapid transport of ions, reducing solid-solid interface resistance of solid-state battery and improving electrochemical performance thereof.
It should be noted, however, that a composite positive electrode material composed of a positive electrode active material, a sulfide electrolyte, and a conductive agent is a determining factor affecting the electrochemical performance of a sulfide solid state battery. The dispersion degree, the contact mode, the contact area and the gap size among all components in the composite positive electrode material can have important influence on the interface stability, the ion transmission rate and the active material utilization rate of a positive electrode active material/sulfide electrolyte, so that the electrochemical performance of the sulfide solid-state battery is influenced.
Currently, methods for preparing sulfide composite cathode materials include a solid phase milling method and a liquid phase method. The sulfide composite positive electrode prepared by the solid-phase grinding method has the problems of uneven dispersion of each component, low effective contact area, serious damage to the morphology/structure of the positive electrode active substance, direct contact of the positive electrode active substance/sulfide solid electrolyte solid-solid interface, continuous interface side reaction and the like. The liquid phase method mainly uses low-polarity solvents such as absolute ethyl alcohol, ethyl propionate, acetonitrile, toluene and the like, although the method is favorable for uniform dispersion and contact of electrodes/electrolyte, the adopted low-polarity solvents have limited dissolving capacity for sulfide electrolyte or precursor components thereof, and solid-liquid interface side reactions are easy to initiate in the liquid phase method process, so that the impurity phase content of the sulfide electrolyte treated by the liquid phase method is increased, the ionic conductivity is reduced, in addition, the solid-solid direct contact of the electrodes/electrolyte cannot be avoided in the liquid phase method treatment process, the continuous interface side reactions can be initiated, the interface impedance is increased, the lithium ion transmission is hindered, and the capacity of the sulfide solid-state battery is influenced.
Therefore, development of a novel composite positive electrode material, increasing the effective interface contact area between the positive electrode active material and the sulfide electrolyte, constructing a high-efficiency ion transmission network, improving the interface stability between the positive electrode active material and the sulfide electrolyte, and playing a vital role in the electrochemical performance of the sulfide solid-state battery.
Disclosure of Invention
The invention mainly aims to overcome the defects of the prior art and provides a composite positive electrode material for a sulfide solid-state battery, and a preparation method and application thereof.
In order to achieve the above purpose, the invention adopts the technical scheme that:
a composite positive electrode material for sulfide solid-state battery is prepared by generating Li-TM-O-S-P (TM=Ni, co, mn) interface buffer layer on the surface of positive electrode active substance particles by mixed solution method, and growing crystalline sulfide in situ at the gap between particles and interface buffer layer.
The obtained three-dimensional ion composite positive electrode active material has a rapid lithium ion transmission network which is spatially and stereoscopically distributed.
The composite positive electrode material is a composite positive electrode active material which is formed by generating an interface buffer layer of Li-TM-O-S-P (TM=Ni, co, mn) on the surfaces of positive electrode active material particles and a conductive agent by utilizing a mixed solution method, growing crystalline sulfide in situ at the gap between the particles and the interface buffer layer to form a three-dimensional ion composite positive electrode active material, and simultaneously forming an anisotropic electron transport network between the composite positive electrode active materials in a bridging manner in the presence of the conductive agent, namely the composite positive electrode active material of a three-dimensional carrier transport network.
The composite positive electrode active material for obtaining the three-dimensional carrier transmission network has a rapid lithium ion transmission network in spatial stereo distribution and an anisotropic electron transmission network in spatial stereo distribution.
The mass ratio of the positive electrode active particles, the crystalline sulfide and the conductive agent in the composite positive electrode material is 30-90:70-10:0-5.
The positive electrode active material particles are positive electrode active materials with high specific capacity; the positive electrode active material with high specific capacity is lithium cobaltate (LiCoO) 2 ) Lithium nickel cobalt manganate (LiNi) a Co b Mn 1-a-b O 2 A is more than or equal to 0.6 and less than 1) and lithium-rich manganese-based layered oxide (xLi) 2 MnO 3 ·(1-x)LiNi a Co b Mn 1-a-b O 2 0 < x < 1, 0.3.ltoreq.a < 1). The conductive agent is one or more of conductive carbon black (SP), carbon nanotubes (carbon nanotubes), vapor Grown Carbon Fiber (VGCF), and Graphene (Graphene).
The preparation method of the composite positive electrode material for the sulfide solid-state battery comprises the steps of generating an interface buffer layer of Li-TM-O-S-P (TM=Ni, co, mn) on the surface of positive electrode active material particles by utilizing a mixed solution method, and growing crystalline sulfide in situ at the gap between the particles and the interface buffer layer to form a three-dimensional ion composite positive electrode active material;
or, the composite positive electrode material is a composite positive electrode active material which is formed by generating an interface buffer layer of Li-TM-O-S-P (TM=Ni, co, mn) on the surfaces of positive electrode active material particles and a conductive agent by utilizing a mixed solution method, growing crystalline sulfide in situ at the gap between the particles and the interface buffer layer to form a three-dimensional ion composite positive electrode active material, and simultaneously forming an anisotropic electron transport network between the composite positive electrode active materials in a bridging manner in the presence of the conductive agent, namely the composite positive electrode active material of the three-dimensional carrier transport network.
Further, all precursor components, positive electrode active material particles or positive electrode active material particles and a conductive agent required by in-situ growth of crystalline sulfide are simultaneously added into a mixed solution, all precursor components of the sulfide are completely dissolved by utilizing the strong nucleophilic action of the mixed solution to form sulfide solid electrolyte precursor liquid, the positive electrode active material particles or the positive electrode active material particles and the conductive agent are dispersed in the formed sulfide solid electrolyte precursor liquid, then interface buffer layer substances containing Li-TM-O-P-S components are formed on the surfaces of the positive electrode active material particles through high-temperature roasting, crystalline sulfide (namely sulfide solid electrolyte particles) is distributed between the surfaces of the interface buffer layer substances and gaps of the positive electrode active material particles, and meanwhile, a heterogeneous electron transmission network is formed among the composite positive electrode active materials in a bridging mode in the presence of the conductive agent, namely the composite positive electrode active material of a three-dimensional carrier transmission network.
When the composite positive electrode active material is prepared, the precursor components required by sulfide are completely dissociated and dissolved in the mixed solution under the strong nucleophilic acting force of the thioanion in the mixed solution by simple heating, so that the precursor component solution of sulfide electrolyte is obtained; and the positive electrode active material particles or the positive electrode active material particles and the conductive agent are dispersed in the formed sulfide solid electrolyte precursor liquid; further heating and absorbing partial sulfide electrolyte precursor components on the surface of positive electrode active material particles through acting force between Co-O-P-S under physical/chemical action; and then further roasting to promote high specific capacity The surface of the positive electrode active material is preformed with a uniform interface buffer layer material containing Li-Co-O-P-S components, and crystalline sulfide electrolyte Li is generated in situ between the interface buffer layer material and the positive electrode active material particles 3 PS 4 Thus obtaining a composite positive electrode block material with a three-dimensional ion transmission network prepared in situ by a mixed solution synthesis method; meanwhile, when the raw materials contain the conductive agent, the composite positive electrode active materials further form an anisotropic electron transmission network in a bridging way, namely the composite positive electrode active material of the three-dimensional carrier transmission network.
The sulfide solid electrolyte precursor liquid is one or more of sulfur-containing lithium salt, sulfur-containing phosphorus salt, halogen-containing lithium salt or sulfur-containing transition metal salt, and is obtained by adding the sulfur-containing lithium salt or the sulfur-containing transition metal salt into a mixed solution, and stirring and reacting for 1-5 hours at the temperature of 40-80 ℃; wherein the mixed solution is the mixture of organic amine and organic mercaptan according to the volume ratio of 100:5-40.
Further, the following is said:
(1) Simultaneously adding positive electrode active material particles and a conductive agent into precursor liquid of sulfide electrolyte according to the mass ratio of 30-90:0-5, and stirring and reacting for 1-5 hours at the temperature of 40-80 ℃ to obtain a solid-liquid mixture in which the positive electrode active material particles and the conductive agent are completely dispersed in the precursor liquid of sulfide electrolyte;
(3) And (3) vacuum drying the obtained solid-liquid mixture for 5-15 hours at 50-100 ℃, roasting for 5-20 hours at 500-800 ℃, firstly forming an interface buffer layer substance containing Li-TM-O-P-S components to wrap the surfaces of high specific capacity anode active substance particles, then forming crystalline sulfide in situ on the surfaces of the interface buffer layer substance and gaps between anode active substance particles by precursor components of sulfide electrolyte, simultaneously forming a heterogeneous electron transmission network between the composite anode active materials in a bridging manner in the presence of a conductive agent, and grinding to obtain the composite anode active material which is prepared in situ by a mixed solution synthesis method, has uniform particle size distribution and is in powder form and has a three-dimensional carrier transmission network.
The sulfur-containing lithium salt is Li 2 S, S; the sulfur-containing phosphor salt is P 2 S 5 The method comprises the steps of carrying out a first treatment on the surface of the Halogen-containing lithium salt as LiCl, liI, liBrOne or more of them.
The organic amine is one or more of ethylenediamine, n-propylamine, propylenediamine and n-butylamine, and the organic mercaptan is one or more of ethanethiol, ethanedithiol, propanethiol, propanedithiol, thiophenol and terephthalethiol.
The precursor of the positive electrode active material particles adopts a solid phase synthesis method or a coprecipitation method to prepare a precursor material of the positive electrode active material, and the precursor material and lithium salt (lithium carbonate and lithium hydroxide) are mixed and ground according to a molar ratio of 1:1.05, and then lithiation reaction is carried out under a high-temperature roasting condition, so that the lithium cobalt oxide, lithium nickel cobalt manganese oxide and lithium-rich manganese-based layered oxide positive electrode material with high specific capacity is finally obtained. The precursor material may be a Transition Metal Carbonate (TMCO) 3 ) Transition metal hydroxide (TM) (OH) 2 ) Or one or more of Transition Metal Oxides (TMO), wherein TM = Ni, co, mn.
The application of the composite positive electrode material for the sulfide solid-state battery is the application of the composite positive electrode material for the sulfide electrolyte all-solid-state battery.
A sulfide electrolyte all-solid-state battery contains the composite positive electrode material for a sulfide solid-state battery.
The cathode of the sulfide electrolyte all-solid-state battery is one of a lithium metal cathode, a lithium-indium cathode, a carbon cathode, a silicon cathode and a silicon-carbon cathode.
The sulfide solid electrolyte in the solid-state battery is Li 6 PS 5 Cl，Li 3 PS 4 ,Li 6 PS 5 Br,Li 10 GeP 2 S 12 One or more of the following.
In the preparation of the sulfide electrolyte all-solid-state battery, 80mg of sulfide solid-state electrolyte Li was first prepared 6 PS 5 Placing Cl powder material into a solid-state battery mould with the diameter of 10mm, applying 200Mpa pressure to form a sulfide electrolyte layer, then placing 10mg of the high-specific-capacity composite positive electrode into the sulfide solid-state electrolyte layer from one side of the positive electrode, applying 800Mpa pressure, and placing a certain mass of negative electrode material into sulfide solid-state electrolysisOn the other side of the mass layer, a pressure of 200Mpa was applied. Finally, the preparation of the sulfide electrolyte solid-state battery is completed through a sealing rubber ring and a pressure mechanical clamp.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
(1) The invention utilizes a mixed solution synthesis method to promote each precursor component of sulfide electrolyte to be completely dissolved in the mixed solution of organic amine and organic mercaptan, obtains precursor liquid of sulfide electrolyte, and realizes uniform mixing and dispersion of positive electrode active substances, conductive agents and sulfide electrolyte precursor components by adding the positive electrode active substances and the conductive agents into the precursor liquid of sulfide electrolyte and heating and stirring the mixture. The method realizes that part of sulfide electrolyte precursor components are adsorbed on the surface of positive electrode active material particles through acting force among TM-O-P-S under the physical/chemical action, and promotes the surface of high specific capacity positive electrode active material to form a uniform interface buffer layer material containing Li-TM-O-P-S components in advance through the subsequent processing steps of vacuum drying, high-temperature roasting and the like, thereby effectively avoiding direct contact between the high specific capacity positive electrode active material and sulfide electrolyte, inhibiting interface side reaction and improving the interface stability of the high specific capacity positive electrode active material and sulfide electrolyte.
(2) The invention utilizes the mixed solution synthesis method and the subsequent vacuum drying and high-power roasting treatment to generate crystalline sulfide electrolyte in situ in the gaps between the particles and the interface buffer layer, realizes the full surface-surface contact of the positive electrode active substance with the sulfide electrolyte with high specific capacity, realizes the efficient three-dimensional lithium ion transmission network construction, is beneficial to improving the utilization rate of the positive electrode active substance and improves the energy density of the all-solid-state battery.
(3) The invention utilizes the mixed solution synthesis method to prepare the high specific capacity composite anode in situ, avoids the problems of uneven dispersion of each component, low effective contact area, serious damage to the morphology/structure of the anode active material, continuous side reaction of the electrode/electrolyte solid-solid interface and the like in the solid phase method for preparing the composite anode, and solves the problems of incomplete dissolution of sulfide electrolyte or precursor components, serious side reaction of the solid-liquid interface, high impurity phase content of the sulfide electrolyte, low ionic conductivity and the like in the traditional liquid phase method for preparing the composite anode.
(4) The technology for preparing the composite positive electrode in situ by using the mixed solution synthesis method has the advantages of simple and mild preparation conditions, and can also improve the content of positive electrode active substances in the composite positive electrode, thereby being beneficial to improving the energy density of the solid-state battery.
Drawings
FIG. 1 is a schematic illustration of the nucleophilic reaction of the sulfide precursor component with the sulfide anion in the (a) organic amine-organic thiol mixed solution and the (b) sulfide electrolyte precursor component in the organic amine-organic thiol mixed solution in example 1.
Fig. 2 is a schematic structural diagram of (a) XPS analysis of the surface of a positive electrode active material in a composite positive electrode material, (b) SEM image of a composite positive electrode powder material, and (c) XRD image of a composite positive electrode material and sulfide electrolyte (d) composite positive electrode material in example 1.
Fig. 3 is (a) XPS and (b) SEM images of the composite positive electrode powder material synthesized by the solid phase method in comparative example 1.
Fig. 4 is a first-turn charge-discharge curve of a sulfide solid-state battery assembled with the composite cathode material prepared in example 1.
Fig. 5 is a cycle performance test of a sulfide solid state battery assembled with the composite positive electrode material prepared in example 1.
Fig. 6 is a first-turn charge-discharge curve of a sulfide solid-state battery assembled with the composite cathode material prepared in comparative example 1.
Fig. 7 is a cycle performance test of a sulfide solid state battery assembled from a composite positive electrode material prepared by the solid phase synthesis in comparative example 1.
Detailed Description
The invention uses lithium-rich manganese-based layered oxide single crystals (0.5 Li) 2 MnO 3 ·0.5LiNi 1/3 Co 1/3 Mn 1/3 O 2 ) Lithium cobalt oxide (LiCoO) 2 ) Monocrystal, nickel cobalt lithium manganate (LiNi) 0.8 Co 0.1 Mn 0.1 O 2 ) Polycrystalline positive electrode material, li 6 PS 5 Cl、Li 3 PS 4 As sulfide electrolyte, vapor phase growth fiber (VGCF), graphene (graphene), conductive carbon black (SP) as conductive agent, and lithium-indium alloy as negative electrode, and respectively adopting a mixed solution synthesis method, a solid phase synthesis method and a solution treatment method to prepare a composite positive electrode material, the invention is further described below with reference to the accompanying drawings and examples:
example 1
The embodiment provides a composite positive electrode material for a sulfide solid-state battery with a three-dimensional ion transmission network, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent VGCF, wherein lithium-rich manganese-based single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the conductive agent VGCF is 40:60:3.
The embodiment also provides a method for preparing the lithium-rich manganese-based sulfide composite positive electrode material with the three-dimensional ion transmission network in situ by using the mixed solution synthesis method, which comprises the following specific steps:
step 1: 42.39mg LiCl, 114.87mg Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 Simultaneously adding 50ml of ethylenediamine and 10ml of ethanethiol into the mixed solution, stirring for 2.5 hours at 65 ℃, and promoting Li under the strong nucleophilic action of the thioanion in the mixed solution 2 S、P 2 S 5 The LiCl component is completely dissociated and dissolved in the mixed solution to obtain a precursor solution of sulfide electrolyte, as shown in fig. 1.
Step 2: 178.9mg of lithium-rich manganese-based single crystal positive electrode material and 13.42mg of VGCF are simultaneously added into the precursor component solution of the sulfide electrolyte, magnetic stirring is carried out for 3 hours at 65 ℃, and part of the precursor component of the sulfide electrolyte is uniformly adsorbed on the surface of positive electrode active material particles through the acting force between TM-O-P-S under the physical/chemical action, so that a solid-liquid mixture is obtained.
Step 3: transferring the obtained solid-liquid mixture into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying at 80 ℃ for 10 hours, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting at high temperature for 15 hours to promote high specific capacity positive electrode activity The uniform interface buffer layer material containing Li-TM-O-P-S component is preformed on the material surface, and crystalline sulfide electrolyte Li is generated in situ between the interface buffer layer material and the positive electrode active material particles 6 PS 5 Cl and simultaneously promote the formation of an anisotropic electron transport network between the positive electrode active material particles through the bridging action of the conductive agent, as shown in fig. 2a and b, thereby obtaining the composite positive electrode bulk material with the three-dimensional carrier transport network prepared in situ by the mixed solution synthesis method.
Step 4: the obtained composite positive electrode material block material is manually ground for 10 minutes in a glove box by utilizing a mortar to obtain crystalline Li 6 PS 5 Cl is uniformly coated on the surface of the interface buffer layer substance and uniformly filled in the gaps of particles of the lithium-rich manganese-based single crystal positive electrode material, wherein crystalline Li is generated in situ 6 PS 5 The particle size of the Cl electrolyte is 0.4-1um, and the coating thickness is 2-4um.
Step 5: 2.297g Li was placed in an argon-filled glove box 2 S，2.222g P 2 S 5 0.848g LiCl was placed in a ball milling pot, and zirconium oxide ball milling beads 20 having a diameter of 10mm were placed, and ball milling was performed at 600rpm for 200 minutes. Then roasting the mixture at 550 ℃ for 8 hours under argon atmosphere to obtain crystalline sulfide electrolyte Li 6 PS 5 Cl bulk material. Finally Li to be obtained in a glove box 6 PS 5 The Cl bulk material was ground for 30 minutes to obtain laboratory-prepared Li as an electrolyte layer of a sulfide solid-state battery 6 PS 5 Cl electrolyte powder material.
Step 6: the lithium-rich manganese-based sulfide composite anode obtained in the step 4 is subjected to Li obtaining in the step 5 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 7: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. As shown in fig. 4 and 5, the composite prepared in situ by the mixed solution synthesis methodThe solid-state battery assembled by the positive electrode has a first-ring discharge capacity of 155.4mAhg -1 The initial coulomb efficiency is 68.6%, and the discharge specific capacity of the solid-state battery still reaches 192.3mAh g after 45 circles of circulation -1 。
Example 2
The embodiment provides a composite positive electrode material for a sulfide solid-state battery with a three-dimensional ion transmission network, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent VGCF, wherein lithium-rich manganese-based single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the conductive agent VGCF is 40:60:3.
The embodiment also provides a method for preparing the lithium-rich manganese-based sulfide composite positive electrode material with the three-dimensional ion transmission network in situ by using the mixed solution synthesis method, which comprises the following specific steps:
step 1: 42.39mg LiCl, 114.87mg Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 Simultaneously adding 50ml of ethylenediamine and 10ml of ethanethiol into the mixed solution, stirring for 2.5 hours at 65 ℃, and promoting Li under the strong nucleophilic action of the thioanion in the mixed solution 2 S、P 2 S 5 And the LiCl component is completely dissociated and dissolved in the mixed solution to obtain the precursor liquid of sulfide electrolyte.
Step 2: 178.9mg of lithium-rich manganese-based single crystal positive electrode material and 13.42mg of VGCF are simultaneously added into the precursor component solution of the sulfide electrolyte, magnetic stirring is carried out for 3 hours at the temperature of 65 ℃, and part of the precursor component of the sulfide electrolyte is uniformly adsorbed on the surface of positive electrode active material particles through the acting force between TM-O-P-S under the physical/chemical action, so that a solid-liquid mixture is obtained.
Step 3: transferring the obtained solid-liquid mixture into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying at 80 ℃ for 10 hours, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting at high temperature for 15 hours to promote the surface of the positive electrode active material with high specific capacity to form a uniform interface buffer layer substance containing Li-TM-O-P-S component in advance, and further forming a solid-liquid mixture on the surface of the positive electrode active material In-situ formation of crystalline sulfide electrolyte Li from interstitial particles of a positive electrode active material 6 PS 5 Cl, thereby obtaining the composite positive electrode bulk material with the three-dimensional ion transmission network prepared in situ by the mixed solution synthesis method.
Step 4: the obtained composite positive electrode material block material is manually ground for 10 minutes in a glove box by utilizing a mortar to obtain crystalline Li 6 PS 5 Cl is uniformly coated on the surface of the interface buffer layer substance and uniformly filled in the gaps of particles of the lithium-rich manganese-based single crystal positive electrode material, wherein crystalline Li is generated in situ 6 PS 5 The particle size of the Cl electrolyte is 0.4-1um, and the coating thickness is 2-4um.
Step 5: the lithium-rich manganese-based sulfide composite anode obtained in the step 4 and Li purchased commercially 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 6: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. Solid-state battery assembled by composite positive electrode prepared in situ by adopting mixed solution synthesis method, and initial-ring discharge capacity reaching 150.1mAh g -1 The initial coulomb efficiency is 67.2%, and the discharge specific capacity of the solid-state battery still reaches 186.2mAh g after 45 circles of circulation -1 。
Example 3
The embodiment provides a composite positive electrode material for a sulfide solid-state battery with a three-dimensional ion transmission network, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent VGCF, wherein lithium-rich manganese-based single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the conductive agent VGCF is 40:60:3.
The embodiment also provides a method for preparing the lithium-rich manganese-based sulfide composite positive electrode material with the three-dimensional ion transmission network in situ by using the mixed solution synthesis method, which comprises the following specific steps:
step 1: in an argon filled glove box, 42.39mg LiCl、114.87mg Li 2 S、111.14mg P 2 S 5 Simultaneously adding 50ml of ethylenediamine and 5ml of ethanethiol into the mixed solution, stirring for 2.5 hours at 65 ℃, and promoting Li under the strong nucleophilic action of the thioanion in the mixed solution 2 S、P 2 S 5 And the LiCl component is completely dissociated and dissolved in the mixed solution to obtain the precursor liquid of sulfide electrolyte.
Step 2: 178.9mg of lithium-rich manganese-based single crystal positive electrode material and 13.42mg of VGCF are simultaneously added into the precursor component solution of the sulfide electrolyte, magnetic stirring is carried out for 3 hours at the temperature of 65 ℃, and part of the precursor component of the sulfide electrolyte is uniformly adsorbed on the surface of positive electrode active material particles through the acting force between TM-O-P-S under the physical/chemical action, so that a solid-liquid mixture is obtained.
Step 3: transferring the obtained solid-liquid mixture into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying at 80 ℃ for 10 hours, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting at high temperature for 15 hours to promote the surface of the positive electrode active material with high specific capacity to form a uniform interface buffer layer material containing Li-TM-O-P-S components in advance, thereby in-situ generating crystalline sulfide electrolyte Li in the gaps of the interface buffer layer material and the positive electrode active material particles 6 PS 5 Cl, thereby obtaining the composite positive electrode bulk material with the three-dimensional ion transmission network prepared in situ by the mixed solution synthesis method.
Step 4: the obtained composite positive electrode material block material is manually ground for 10 minutes in a glove box by utilizing a mortar to obtain crystalline Li 6 PS 5 Cl is uniformly coated on the surface of the interface buffer layer substance and uniformly filled in the gaps of particles of the lithium-rich manganese-based single crystal positive electrode material, wherein crystalline Li is generated in situ 6 PS 5 The particle size of the Cl electrolyte is 0.4-1um, and the coating thickness is 2-4um.
Step 5: the lithium-rich manganese-based sulfide composite anode obtained in the step 4 and the lithium prepared in the laboratory obtained in the step 5 of the example 1 6 PS 5 Cl sulfide electrolyte powder material and lithium-indium alloy negative electrode material are placed in a glove box filled with argon gas Assembled into a sulfide solid state battery.
Step 6: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. Solid-state battery assembled by composite positive electrode prepared in situ by adopting mixed solution synthesis method, and initial-ring discharge capacity reaching 149.6mAh g -1 The initial coulomb efficiency is 66.3%, and the specific discharge capacity of the solid-state battery still reaches 173.2mAh g after 45 circles of circulation -1 。
Example 4
The embodiment provides a composite positive electrode material for a sulfide solid-state battery with a three-dimensional ion transmission network, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent VGCF, wherein lithium-rich manganese-based single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the conductive agent VGCF is 40:60:3.
The embodiment also provides a method for preparing the lithium-rich manganese-based sulfide composite positive electrode material with the three-dimensional ion transmission network in situ by using the mixed solution synthesis method, which comprises the following specific steps:
step 1: 42.39mg LiCl, 114.87mg Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 Simultaneously adding 50ml of ethylenediamine and 15ml of ethanethiol into the mixed solution, stirring for 2.5 hours at 65 ℃, and promoting Li under the strong nucleophilic action of the thioanion in the mixed solution 2 S、P 2 S 5 And the LiCl component is completely dissociated and dissolved in the mixed solution to obtain the precursor liquid of sulfide electrolyte.
Step 2: 178.9mg of lithium-rich manganese-based single crystal positive electrode material and 13.42mg of VGCF are simultaneously added into the precursor component solution of the sulfide electrolyte, magnetic stirring is carried out for 3 hours at the temperature of 65 ℃, and part of the precursor component of the sulfide electrolyte is uniformly adsorbed on the surface of positive electrode active material particles through the acting force between TM-O-P-S under the physical/chemical action, so that a solid-liquid mixture is obtained.
Step 3: transferring the obtained solid-liquid mixture to a vacuum connected with a glove box filled with argonVacuum drying in a hollow tube furnace at 80deg.C for 10 hr, heating to 700deg.C at a heating rate of 2deg.C/min, and high-temperature roasting for 15 hr to promote the surface of high specific capacity positive electrode active material to form uniform interface buffer layer material containing Li-TM-O-P-S component, thereby in situ forming crystalline sulfide electrolyte Li in the gaps between the interface buffer layer material and the positive electrode active material particles 6 PS 5 Cl, thereby obtaining the composite positive electrode bulk material with the three-dimensional ion transmission network prepared in situ by the mixed solution synthesis method.
Step 4: the obtained composite positive electrode material block material is manually ground for 10 minutes in a glove box by utilizing a mortar to obtain crystalline Li 6 PS 5 Cl is uniformly coated on the surface of the interface buffer layer substance and uniformly filled in the gaps of particles of the lithium-rich manganese-based single crystal positive electrode material, wherein crystalline Li is generated in situ 6 PS 5 The particle size of the Cl electrolyte is 0.4-1um, and the coating thickness is 2-4um.
Step 5: the lithium-rich manganese-based sulfide composite anode obtained in the step 4 is obtained in the example step 5 to obtain Li prepared in a laboratory 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 6: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. Solid-state battery assembled by composite positive electrode prepared in situ by adopting mixed solution synthesis method, and first-ring discharge capacity reaching 148.7mAh g -1 The initial coulomb efficiency is 66.1%, and the specific discharge capacity of the solid-state battery still reaches 177.6mAh g after 45 circles of circulation -1 。
Example 5
The embodiment provides a composite positive electrode material for a sulfide solid-state battery with a three-dimensional ion transmission network, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent graphene, wherein the lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent The mass ratio of the graphene is 40:60:3.
The embodiment also provides a method for preparing the lithium-rich manganese-based sulfide composite positive electrode material with the three-dimensional ion transmission network in situ by using the mixed solution synthesis method, which comprises the following specific steps:
step 1: 42.39mg LiCl, 114.87mg Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 Simultaneously adding 50ml of ethylenediamine and 5ml of ethanedithiol into the mixed solution, stirring at 60 ℃ for 3 hours, and promoting Li under the strong nucleophilic action of the thioanion in the mixed solution 2 S、P 2 S 5 The LiCl component is completely dissociated and dissolved in the mixed solution to obtain a precursor component solution of the sulfide electrolyte.
Step 2: 178.9mg of lithium-rich manganese-based single crystal positive electrode material and 13.42mg of graphene are simultaneously added into the precursor component solution of the sulfide electrolyte, and are magnetically stirred at 60 ℃ for 3 hours, and part of the precursor component of the sulfide electrolyte is uniformly adsorbed on the surface of positive electrode active material particles through the acting force between TM-O-P-S under the physical/chemical action, so that a solid-liquid mixture is obtained.
Step 3: transferring the obtained solid-liquid mixture into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying at 80 ℃ for 10 hours, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting at high temperature for 15 hours to promote the surface of the positive electrode active material with high specific capacity to form a uniform interface buffer layer material containing Li-TM-O-P-S components in advance, thereby in-situ generating crystalline sulfide electrolyte Li in the gaps of the interface buffer layer material and the positive electrode active material particles 6 PS 5 Cl, thereby obtaining the composite positive electrode bulk material with the three-dimensional ion transmission network prepared in situ by the mixed solution synthesis method.
Step 4: the obtained high specific capacity composite positive electrode material is manually ground for 10 minutes in a glove box by utilizing a mortar, so that each component is uniformly dispersed and crystalline Li is obtained 6 PS 5 The Cl is uniformly coated on the surface of the interface buffer layer substance and is a composite positive electrode powder material of the particle gaps of the lithium-rich manganese-based single crystal positive electrode material, wherein the composite positive electrode powder material is generated in situCrystalline Li of (2) 6 PS 5 The particle size of the Cl electrolyte is 0.4-1um, and the coating thickness is 2-4um.
Step 5: the lithium-rich manganese-based sulfide composite positive electrode prepared in the step 4 and the step 5 of the example 1 are obtained to obtain Li prepared in a laboratory 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 6: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. Solid-state battery assembled by composite positive electrode material prepared in situ by adopting mixed solution synthesis method, and initial ring discharge capacity reaches 145.1mAh g -1 The initial coulomb efficiency is 67.2%, and the discharge specific capacity of the solid-state battery still reaches 185.5mAh g after 45 circles of circulation -1 。
Example 6
The embodiment provides a composite positive electrode material for a sulfide solid-state battery with a three-dimensional ion transmission network, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent VGCF, wherein lithium-rich manganese-based single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the conductive agent VGCF is 40:60:3.
The method comprises the following specific steps:
step 1: 42.39mg LiCl, 114.87mg Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 Simultaneously adding 50ml of ethylenediamine and 10ml of phenylmercaptan into the mixed solution, stirring at 65 ℃ for 2.5 hours to promote Li 2 S、P 2 S 5 And the LiCl component is completely dissociated and dissolved in the mixed solution to obtain the precursor liquid of sulfide electrolyte.
Step 2: 178.9mg of lithium-rich manganese-based single crystal positive electrode material and 13.42mg of VGCF are simultaneously added into the precursor component solution of the sulfide electrolyte, magnetic stirring is carried out for 3 hours at the temperature of 65 ℃, and part of the precursor component of the sulfide electrolyte is uniformly adsorbed on the surface of positive electrode active material particles through the acting force between TM-O-P-S under the physical/chemical action, so that a solid-liquid mixture is obtained.
Step 3: transferring the obtained solid-liquid mixture into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying at 80 ℃ for 10 hours, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting at high temperature for 15 hours to promote the surface of the positive electrode active material with high specific capacity to form a uniform interface buffer layer material containing Li-TM-O-P-S components in advance, thereby in-situ generating crystalline sulfide electrolyte Li in the gaps of the interface buffer layer material and the positive electrode active material particles 6 PS 5 Cl, thereby obtaining the composite positive electrode bulk material with the three-dimensional ion transmission network prepared in situ by the mixed solution synthesis method.
Step 4: the obtained composite positive electrode material block material is manually ground for 10 minutes in a glove box by utilizing a mortar to obtain crystalline Li 6 PS 5 Cl is uniformly coated on the surface of the interface buffer layer substance and uniformly filled in the gaps of particles of the lithium-rich manganese-based single crystal positive electrode material, wherein crystalline Li is generated in situ 6 PS 5 The particle size of the Cl electrolyte is 0.4-1um, and the coating thickness is 2-4um.
Step 5: lithium-rich manganese-based sulfide composite anode and Li prepared in laboratory 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 6: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. Solid-state battery assembled by composite positive electrode prepared in situ by adopting mixed solution synthesis method, and first-ring discharge capacity reaching 136.6mAh g -1 The initial coulomb efficiency is 66.9%, and the specific discharge capacity of the solid-state battery still reaches 176.8mAh g after 45 circles of circulation -1 。
Example 7
The embodiment provides a composite positive electrode material for a sulfide solid state battery with a three-dimensional ion transmission network, which comprises a high-voltage lithium cobalt oxide single crystal positive electrode material and Li 3 PS 4 Sulfide electrolyte and conductive agentVGCF, wherein high-voltage lithium cobaltate single crystal positive electrode material, li 3 PS 4 The mass ratio of sulfide electrolyte to conductive agent VGCF is 70:30:0.
The embodiment also provides a method for preparing the lithium cobaltate sulfide composite anode material with the three-dimensional ion transmission network in situ by using the mixed solution synthesis method, which comprises the following specific steps:
step 1: 68.92mg of Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 Simultaneously adding 100ml of propylamine and 15ml of propanethiol into the mixed solution, stirring for 3 hours at 65 ℃ and promoting Li under the strong nucleophilic action of the thioanion in the mixed solution 2 S、P 2 S 5 The components are completely dissociated and dissolved in the mixed solution to obtain a precursor component solution of the sulfide electrolyte.
Step 2: 626.25mg of a high-voltage lithium cobaltate single crystal positive electrode material was simultaneously added to the precursor component solution of the sulfide electrolyte, and magnetically stirred at 65 ℃ for 4 hours, and part of the sulfide electrolyte precursor component was adsorbed uniformly on the surface of the positive electrode active material particles by the action force between Co-O-P-S under the physical/chemical action, and a solid-liquid mixture was obtained. .
Step 3: transferring the obtained solid-liquid mixture into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying at 90 ℃ for 12 hours, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting at high temperature for 15 hours, so as to promote the surface of the positive electrode active material with high specific capacity to form a uniform interface buffer layer material containing Li-Co-O-P-S components in advance, and further forming crystalline sulfide electrolyte Li in situ in the gaps of the interface buffer layer material and the positive electrode active material particles 3 PS 4 Thus obtaining the composite positive electrode bulk material with the three-dimensional ion transmission network prepared in situ by the mixed solution synthesis method.
Step 4: the obtained composite positive electrode material is manually ground for 10 minutes by utilizing a mortar in a glove box, so that each component is uniformly dispersed, and crystalline Li is obtained 3 PS 4 Uniformly coating the surface of the interface buffer layer material and the high-voltage lithium cobalt oxide single crystal positive electrode materialComposite positive electrode powder material with particle gaps. Wherein Li is 3 PS 4 The particle size of the electrolyte is 0.2-0.8um, and the coating thickness is 1-4um.
Step 5: li laboratory prepared in step 5 of example 1, a lithium cobalt oxide sulfide composite positive electrode obtained in step 4 was obtained 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 6: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 3.0 to 4.5V (vs. Li + /Li)、0.1C(1C＝140mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. Solid-state battery assembled by composite positive electrode prepared in situ by adopting mixed solution synthesis method, and initial-ring discharge capacity reaching 116.3mAh g -1 The initial coulomb efficiency is 87.5%, and the discharge specific capacity of the solid-state battery reaches 103.7mAh g after 45 circles of circulation -1 。
Example 8
The embodiment provides a composite positive electrode material for a sulfide solid state battery with a three-dimensional ion transport network, which comprises nickel cobalt lithium manganate (LiNi 0.8 Co 0.1 Mn 0.1 O 2 ) Single crystal positive electrode material, li 6 PS 5 Cl sulfide electrolyte and conductive carbon black (SP), wherein a lithium nickel cobalt manganese oxide single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the SP is 70:30:3.
The embodiment also provides a method for preparing the nickel cobalt lithium manganate sulfide composite positive electrode material with the three-dimensional ion transmission network in situ by the mixed solution synthesis method, which comprises the following specific steps:
step 1: 42.39mg LiCl, 114.87mg Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 Simultaneously adding 100ml of n-butylamine and 10ml of ethanedithiol into the mixed solution, stirring for 2 hours at 65 ℃ and promoting Li under the strong nucleophilic action of the thioanion in the mixed solution 2 S、P 2 S 5 The LiCl component is completely dissociated and dissolved in the mixed solution to obtain a precursor component solution of the sulfide electrolyte.
Step 2: 626.25mg of lithium nickel cobalt manganese oxide single crystal positive electrode material and 26.84mg of SP are simultaneously added into the precursor component solution of the sulfide electrolyte, and magnetic stirring is carried out for 3 hours at 65 ℃, part of the precursor component of the sulfide electrolyte is uniformly adsorbed on the surface of positive electrode active material particles through the acting force between TM-O-P-S under the physical/chemical action, and a solid-liquid mixture is obtained.
Step 3: transferring the obtained solid-liquid mixture into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying at 90 ℃ for 12 hours, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting at high temperature for 15 hours, so as to promote the surface of the positive electrode active material with high specific capacity to form a uniform interface buffer layer material containing Li-TM-O-P-S components in advance, and further forming crystalline sulfide electrolyte Li in situ in gaps between the interface buffer layer material and positive electrode active material particles 6 PS 5 Cl, thereby obtaining the composite positive electrode bulk material with the three-dimensional ion transmission network prepared in situ by the mixed solution synthesis method.
Step 4: the obtained composite positive electrode material is manually ground for 10 minutes by utilizing a mortar in a glove box, so that each component is uniformly dispersed, and crystalline Li is obtained 6 PS 5 Cl is uniformly coated on the surface of the interface buffer layer substance and is a composite positive electrode powder material of nickel cobalt lithium manganate monocrystal positive electrode material particle gaps, wherein Li is as follows 6 PS 5 The particle size of the Cl electrolyte is 0.2-1um, and the coating thickness is 2-4um.
Step 5: the nickel cobalt lithium manganate sulfide composite anode obtained in the step 4 is prepared into Li in a laboratory 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 6: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 3.0 to 4.4V (vs. Li + /Li)、0.1C(1C＝200mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. Solid-state battery assembled by composite positive electrode material prepared in situ by adopting mixed solution synthesis method, and initial-ring discharge capacity reaches 120.5mAh g -1 The initial coulomb efficiency is 86.8%, and the discharge specific capacity of the solid-state battery reaches 112.3m after 45 circles of circulationAh g -1 。
Comparative example 1
The embodiment provides a composite positive electrode material for sulfide solid-state batteries, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent VGCF, wherein lithium-rich manganese-based single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the conductive agent VGCF is 40:60:3.
The embodiment also provides a preparation method for synthesizing the lithium-rich manganese-based sulfide composite anode material by a solid phase method, which comprises the following specific steps:
step 1: 178.9mg of lithium-rich manganese-based single crystal positive electrode material, 13.42mg of VGCF, and 268.394mg of Li are placed in a glove box filled with argon 6 PS 5 And (3) fully and manually grinding Cl for 30 minutes by utilizing a mortar to obtain the lithium-rich manganese-based sulfide composite anode powder material prepared by the solid phase method.
Step 2: compounding lithium-rich manganese-based sulfide with positive electrode and Li 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 3: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. As shown in fig. 6 and 7, the solid-state battery assembled by the composite positive electrode prepared by the solid-state method has a first-turn discharge capacity of 70.81mAh g -1 The initial coulomb efficiency is only 60.43%, and the discharge capacity after 45 circles of circulation is only 130.65mAh g -1 。
Comparative example 2
The embodiment provides a composite positive electrode material for sulfide solid-state batteries, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent VGCF, wherein lithium-rich manganese-based single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the conductive agent VGCF is 40:60:3.
The embodiment also provides a preparation method for synthesizing the lithium-rich manganese-based sulfide composite anode material by a solution treatment method, which comprises the following specific steps:
step 1: 42.39mg LiCl, 114.87mg Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 Simultaneously adding 50ml of ethylenediamine solution, and stirring at 65deg.C for 2.5 hr to find Li 2 S、P 2 S 5 The components such as LiCl and the like can not be completely dissociated in the ethylenediamine solution to obtain Li 2 S、P 2 S 5 Solid-liquid mixtures of LiCl ethylenediamine solutions.
Step 2: 178.9mg of lithium-rich manganese-based single crystal positive electrode material and 13.42mg of VGCF were simultaneously added to the above Li in a glove box filled with argon gas 2 S、P 2 S 5 Magnetically stirring the mixture of LiCl and ethylenediamine solution for 6 hours at 60 ℃ to obtain a lithium-rich manganese-based positive electrode material, and a sulfide electrolyte precursor component Li 2 S、P 2 S 5 Solid-liquid mixed slurry of LiCl and ethylenediamine solution.
Step 3: transferring the solid-liquid mixed slurry into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying for 10 hours at 80 ℃, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting for 15 hours at high temperature to obtain the lithium-rich manganese-based sulfide composite positive electrode block material prepared by an ethylenediamine solution treatment method.
Step 4: and (3) manually grinding the lithium-rich manganese-based sulfide composite anode material prepared by the ethylenediamine solution treatment method in a glove box for 20 minutes by using a mortar to obtain the lithium-rich manganese-based sulfide composite anode powder material.
Step 4: lithium-rich manganese-based sulfide composite positive electrode material prepared by ethylenediamine solution treatment method and Li 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 5: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. Composite positive electrode assembled sulfide solid-state battery prepared by ethylenediamine solution treatment method and having first-turn discharge capacity of 40.3mAh g -1 The initial coulomb efficiency is 63.1%, and the discharge specific capacity of the solid-state battery after 45 circles is only 30.5mAh g -1 。
Comparative example 3
The embodiment provides a composite positive electrode material for sulfide solid-state batteries, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent VGCF, wherein lithium-rich manganese-based single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the conductive agent VGCF is 40:60:3.
The embodiment also provides a preparation method for synthesizing the lithium-rich manganese-based sulfide composite anode material by a solution treatment method, which comprises the following specific steps:
Step 1: 42.39mg LiCl, 114.87mg Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 Simultaneously adding 10ml of ethanethiol solution, and stirring at 65deg.C for 2.5 hr to find Li 2 S、P 2 S 5 The components such as LiCl and the like can not be completely dissociated in the ethanethiol solution to obtain Li 2 S、P 2 S 5 Solid-liquid mixtures of LiCl ethanethiol solutions.
Step 2: 178.9mg of lithium-rich manganese-based single crystal positive electrode material and 13.42mg of VGCF were simultaneously added to the above Li in a glove box filled with argon gas 2 S、P 2 S 5 Magnetically stirring the mixture of LiCl and ethanethiol solution for 6 hours at the temperature of 60 ℃ to obtain the lithium-rich manganese-based positive electrode material, and the sulfide electrolyte precursor component Li 2 S、P 2 S 5 Solid-liquid mixed slurry of LiCl and ethanethiol solution.
Step 3: transferring the solid-liquid mixed slurry into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying for 10 hours at 80 ℃, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting for 15 hours at high temperature to obtain the lithium-rich manganese-based sulfide composite positive electrode block material prepared by the ethanethiol solution treatment method.
Step 4: and (3) manually grinding the lithium-rich manganese-based sulfide composite anode material prepared by the ethanethiol solution treatment method in a glove box for 20 minutes by utilizing a mortar to obtain the lithium-rich manganese-based sulfide composite anode powder material.
Step 4: lithium-rich manganese-based sulfide composite positive electrode material prepared by ethanethiol solution treatment method and Li 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 5: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. The first-turn discharge capacity is 50.1mAh g -1 The initial coulomb efficiency is 64.3%, and the discharge specific capacity of the solid-state battery after 45 circles is only 43.6mAh g -1 。
Comparative example 4
The embodiment provides a composite positive electrode material for sulfide solid-state batteries, which comprises a lithium-rich manganese-based single crystal positive electrode material and Li 6 PS 5 Cl sulfide electrolyte and conductive agent VGCF, wherein lithium-rich manganese-based single crystal positive electrode material, li 6 PS 5 The mass ratio of the Cl sulfide electrolyte to the conductive agent VGCF is 40:60:3.
The embodiment also provides a preparation method for synthesizing the lithium-rich manganese-based sulfide composite anode material by a physical mixing method, which comprises the following specific steps:
step 1: 42.39mg LiCl, 114.87mg Li were placed in an argon-filled glove box 2 S、111.14mg P 2 S 5 The precursor component of the sulfide electrolyte was physically ground with 178.9mg of a lithium-rich manganese-based single crystal positive electrode material and 13.42mg of VGCF at room temperature for 0.5 hours using a mortar to obtain a solid-solid mixture in which each solid component was uniformly mixed.
Step 2: transferring the solid-solid mixture into a vacuum tube furnace connected with a glove box filled with argon, vacuum drying for 10 hours at 80 ℃, then heating to 700 ℃ at a heating rate of 2 ℃/min, and roasting for 15 hours at high temperature to obtain the lithium-rich manganese-based sulfide composite positive electrode block material prepared by a physical mixing method.
Step 3: and manually grinding the lithium-rich manganese-based sulfide composite positive electrode bulk material in a glove box by using a mortar for 20 minutes to obtain the lithium-rich manganese-based sulfide composite positive electrode powder material.
Step 4: compounding lithium-rich manganese-based sulfide with positive electrode powder material and Li 6 PS 5 The Cl sulfide electrolyte powder material and the lithium-indium alloy negative electrode material are assembled into a sulfide solid-state battery in a glove box filled with argon.
Step 5: the assembled sulfide solid state battery was subjected to a temperature of 30℃and a voltage of 2.0 to 4.7V (vs. Li + /Li)、0.1C(1C＝250mAg -1 ) And (5) performing charge and discharge test under the multiplying power condition. The first-turn discharge capacity is 45.3mAh g -1 The initial coulomb efficiency is 59.3%, and the discharge specific capacity of the solid-state battery after 45 circles is only 39.5mAh g -1 。
In summary, the method utilizes the strong nucleophilic action of the thioanion in the mixed solution of the organic amine and the organic mercaptan to realize the complete dissolution of the sulfide electrolyte precursor component, further utilizes the mixed solution method to generate the interface buffer layer of Li-TM-O-S-P (TM=Ni, co, mn) on the surface of the anode active material particles, and grows crystalline sulfide in situ at the gaps between the particles and the interface buffer layer, thus constructing the composite anode active material with three-dimensional ion transmission network characteristics. In particular, when ethylenediamine and ethanethiol are selected as specific organic amine and organic thiol solvents, and the amounts of ethylenediamine and ethanethiol are fixed to be 50ml and 10ml, respectively, the prepared composite cathode material for sulfide solid-state batteries has optimal electrochemical properties.
The invention is not a matter of the known technology.
The above embodiments are provided to illustrate the technical concept and features of the present invention and are intended to enable those skilled in the art to understand the content of the present invention and implement the same, and are not intended to limit the scope of the present invention. All equivalent changes or modifications made in accordance with the spirit of the present invention should be construed to be included in the scope of the present invention.
Claims (10)
1. A composite positive electrode material for sulfide solid-state batteries is characterized in that: the composite positive electrode material is a three-dimensional ion composite positive electrode active material which is formed by generating an interface buffer layer of Li-TM-O-S-P (TM=Ni, co, mn) on the surface of positive electrode active material particles by utilizing a mixed solution method and growing crystalline sulfide in situ at the gap between the particles and the interface buffer layer.
2. The composite positive electrode material for a sulfide solid state battery according to claim 1, characterized in that: the composite positive electrode material is a composite positive electrode active material which is formed by generating an interface buffer layer of Li-TM-O-S-P (TM=Ni, co, mn) on the surfaces of positive electrode active material particles and a conductive agent by utilizing a mixed solution method, growing crystalline sulfide in situ at the gap between the particles and the interface buffer layer to form a three-dimensional ion composite positive electrode active material, and simultaneously forming an anisotropic electron transport network between the composite positive electrode active materials in a bridging manner in the presence of the conductive agent, namely the composite positive electrode active material of a three-dimensional carrier transport network.
3. The composite positive electrode material for a sulfide solid state battery according to claim 1 or 2, characterized in that: the mass ratio of the positive electrode active particles, the crystalline sulfide and the conductive agent in the composite positive electrode material is 30-90:70-10:0-5.
4. The composite positive electrode material for a sulfide solid state battery according to claim 3, characterized in that: the positive electrode active material particles are positive electrode active materials with high specific capacity; the positive electrode active material with high specific capacity is lithium cobaltate (LiCoO) 2 ) Lithium nickel cobalt manganate (LiNi) a Co b Mn 1-a-b O 2 A is more than or equal to 0.6 and less than 1) and lithium-rich manganese-based layered oxide (xLi) 2 MnO 3 ·(1-x)LiNi a Co b Mn 1-a-b O 2 0 < x < 1, 0.3.ltoreq.a < 1). The conductive agent is one or more of conductive carbon black (SP), carbon nanotubes (carbon nanotubes), vapor Grown Carbon Fiber (VGCF), and Graphene (Graphene).
5. A method for preparing the composite positive electrode material for sulfide solid-state batteries according to claim 1, characterized in that: the composite positive electrode material is a three-dimensional ion composite positive electrode active material which is formed by generating an interface buffer layer of Li-TM-O-S-P (TM=Ni, co, mn) on the surface of positive electrode active material particles by utilizing a mixed solution method and growing crystalline sulfide in situ at the gap between the particles and the interface buffer layer;
Or, the composite positive electrode material is a composite positive electrode active material which is formed by generating an interface buffer layer of Li-TM-O-S-P (TM=Ni, co, mn) on the surfaces of positive electrode active material particles and a conductive agent by utilizing a mixed solution method, growing crystalline sulfide in situ at the gap between the particles and the interface buffer layer to form a three-dimensional ion composite positive electrode active material, and simultaneously forming an anisotropic electron transport network between the composite positive electrode active materials in a bridging manner in the presence of the conductive agent, namely the composite positive electrode active material of the three-dimensional carrier transport network.
6. The method for producing a composite positive electrode material for a sulfide solid state battery according to claim 5, characterized in that: all precursor components, positive electrode active material particles or positive electrode active material particles and a conductive agent required by in-situ growth of crystalline sulfide are simultaneously added into a mixed solution, all precursor components of the sulfide are completely dissolved by utilizing the strong nucleophilic effect of the mixed solution to form sulfide solid electrolyte precursor liquid, the positive electrode active material particles or the positive electrode active material particles and the conductive agent are dispersed in the formed sulfide solid electrolyte precursor liquid, then interface buffer layer substances containing Li-TM-O-P-S components are formed on the surfaces of the positive electrode active material particles through high-temperature roasting, crystalline sulfide (namely sulfide solid electrolyte particles) is distributed between the surfaces of the interface buffer layer substances and gaps of the positive electrode active material particles, and meanwhile, a heterogeneous electron transmission network is formed among the composite positive electrode active materials in a bridging mode in the presence of the conductive agent, namely the composite positive electrode active material of a three-dimensional carrier transmission network.
7. The method for producing a composite positive electrode material for a sulfide solid state battery according to claim 6, characterized in that: the sulfide solid electrolyte precursor liquid is one or more of sulfur-containing lithium salt, sulfur-containing phosphorus salt, halogen-containing lithium salt or sulfur-containing transition metal salt, and is obtained by adding the sulfur-containing lithium salt or the sulfur-containing transition metal salt into a mixed solution, and stirring and reacting for 1-5 hours at the temperature of 40-80 ℃; wherein the mixed solution is prepared by mixing organic amine and organic mercaptan according to the volume ratio of 100:5-40; the organic amine is one or more of ethylenediamine, n-propylamine, propylenediamine and n-butylamine, and the organic mercaptan is one or more of ethanethiol, ethanedithiol, propanethiol, propanedithiol, thiophenol and terephthalethiol.
8. The method for producing a composite positive electrode material for a sulfide solid state battery according to any one of claims 5 to 7, characterized in that:
(1) Simultaneously adding positive electrode active material particles and a conductive agent into precursor liquid of sulfide electrolyte according to the mass ratio of 30-90:0-5, and stirring and reacting for 1-5 hours at the temperature of 40-80 ℃ to obtain a solid-liquid mixture in which the positive electrode active material particles and the conductive agent are completely dispersed in the precursor liquid of sulfide electrolyte;
(3) And (3) vacuum drying the obtained solid-liquid mixture for 5-15 hours at 50-100 ℃, roasting for 5-20 hours at 500-800 ℃, firstly forming an interface buffer layer substance containing Li-TM-O-P-S components to wrap the surfaces of high specific capacity anode active substance particles, then forming crystalline sulfide in situ on the surfaces of the interface buffer layer substance and gaps between anode active substance particles by precursor components of sulfide electrolyte, simultaneously forming a heterogeneous electron transmission network between the composite anode active materials in a bridging manner in the presence of a conductive agent, and grinding to obtain the composite anode active material which is prepared in situ by a mixed solution synthesis method, has uniform particle size distribution and is in powder form and has a three-dimensional carrier transmission network.
9. Use of the composite positive electrode material according to claim 1, characterized in that: the application of the composite positive electrode material for the sulfide solid-state battery in preparing the sulfide electrolyte all-solid-state battery is described in the claim 1.
10. A sulfide electrolyte all-solid-state battery characterized in that: the composite positive electrode material for a sulfide solid-state battery according to claim 1.
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