CN116979013A - Electrode preparation method, electrode and battery - Google Patents
Electrode preparation method, electrode and battery Download PDFInfo
- Publication number
- CN116979013A CN116979013A CN202310856019.5A CN202310856019A CN116979013A CN 116979013 A CN116979013 A CN 116979013A CN 202310856019 A CN202310856019 A CN 202310856019A CN 116979013 A CN116979013 A CN 116979013A
- Authority
- CN
- China
- Prior art keywords
- electrode
- conductive
- adhesive
- powder
- mixing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000002360 preparation method Methods 0.000 title claims abstract description 25
- 239000000835 fiber Substances 0.000 claims abstract description 166
- 239000000843 powder Substances 0.000 claims abstract description 100
- 239000000853 adhesive Substances 0.000 claims abstract description 98
- 230000001070 adhesive effect Effects 0.000 claims abstract description 98
- 238000002156 mixing Methods 0.000 claims abstract description 80
- 239000006258 conductive agent Substances 0.000 claims abstract description 62
- 239000002904 solvent Substances 0.000 claims abstract description 51
- 239000012528 membrane Substances 0.000 claims abstract description 50
- 238000004519 manufacturing process Methods 0.000 claims abstract description 29
- 239000013543 active substance Substances 0.000 claims abstract description 11
- 239000000463 material Substances 0.000 claims description 49
- 239000000203 mixture Substances 0.000 claims description 44
- 239000011230 binding agent Substances 0.000 claims description 41
- 238000000034 method Methods 0.000 claims description 41
- -1 polytetrafluoroethylene Polymers 0.000 claims description 37
- 239000003292 glue Substances 0.000 claims description 36
- 238000010008 shearing Methods 0.000 claims description 35
- 238000007731 hot pressing Methods 0.000 claims description 30
- 239000012790 adhesive layer Substances 0.000 claims description 27
- 125000004432 carbon atom Chemical group C* 0.000 claims description 27
- 230000008569 process Effects 0.000 claims description 25
- 239000002245 particle Substances 0.000 claims description 21
- 238000001035 drying Methods 0.000 claims description 20
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 19
- 239000006185 dispersion Substances 0.000 claims description 19
- 239000000839 emulsion Substances 0.000 claims description 19
- 239000002033 PVDF binder Substances 0.000 claims description 17
- 239000011149 active material Substances 0.000 claims description 17
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 17
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 16
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 16
- 229920002125 Sokalan® Polymers 0.000 claims description 13
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 11
- 239000003273 ketjen black Substances 0.000 claims description 10
- 239000007788 liquid Substances 0.000 claims description 9
- 229920001577 copolymer Polymers 0.000 claims description 8
- 239000007784 solid electrolyte Substances 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 239000006230 acetylene black Substances 0.000 claims description 6
- 229920000058 polyacrylate Polymers 0.000 claims description 6
- 239000004584 polyacrylic acid Substances 0.000 claims description 6
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 6
- 229920000193 polymethacrylate Polymers 0.000 claims description 6
- 229920005989 resin Polymers 0.000 claims description 6
- 239000011347 resin Substances 0.000 claims description 6
- 239000007787 solid Substances 0.000 claims description 6
- 229910002804 graphite Inorganic materials 0.000 claims description 5
- 239000010439 graphite Substances 0.000 claims description 5
- 238000000926 separation method Methods 0.000 claims description 5
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 4
- 206010016654 Fibrosis Diseases 0.000 claims description 4
- 239000002041 carbon nanotube Substances 0.000 claims description 4
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 4
- 230000004761 fibrosis Effects 0.000 claims description 4
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 3
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 3
- 239000004917 carbon fiber Substances 0.000 claims description 3
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims description 3
- 150000001733 carboxylic acid esters Chemical class 0.000 claims description 3
- 229910021389 graphene Inorganic materials 0.000 claims description 3
- 150000008282 halocarbons Chemical class 0.000 claims description 3
- 125000000101 thioether group Chemical group 0.000 claims description 3
- 150000004651 carbonic acid esters Chemical class 0.000 claims description 2
- 239000001768 carboxy methyl cellulose Substances 0.000 claims description 2
- 239000008112 carboxymethyl-cellulose Substances 0.000 claims description 2
- 150000001335 aliphatic alkanes Chemical class 0.000 claims 1
- 150000001408 amides Chemical class 0.000 claims 1
- 150000002576 ketones Chemical class 0.000 claims 1
- 229920005569 poly(vinylidene fluoride-co-hexafluoropropylene) Polymers 0.000 claims 1
- HNJBEVLQSNELDL-UHFFFAOYSA-N pyrrolidin-2-one Chemical compound O=C1CCCN1 HNJBEVLQSNELDL-UHFFFAOYSA-N 0.000 claims 1
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 15
- 238000005096 rolling process Methods 0.000 description 15
- 238000010438 heat treatment Methods 0.000 description 12
- 238000005520 cutting process Methods 0.000 description 11
- 238000004804 winding Methods 0.000 description 11
- 238000007664 blowing Methods 0.000 description 10
- 238000003475 lamination Methods 0.000 description 10
- 238000003801 milling Methods 0.000 description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 7
- 229910052782 aluminium Inorganic materials 0.000 description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 6
- 230000008901 benefit Effects 0.000 description 6
- 238000001914 filtration Methods 0.000 description 6
- 239000004576 sand Substances 0.000 description 6
- 229910021383 artificial graphite Inorganic materials 0.000 description 5
- 229910052744 lithium Inorganic materials 0.000 description 5
- 238000003825 pressing Methods 0.000 description 5
- 239000011734 sodium Substances 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- 238000001132 ultrasonic dispersion Methods 0.000 description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 238000005469 granulation Methods 0.000 description 4
- 230000003179 granulation Effects 0.000 description 4
- 238000009775 high-speed stirring Methods 0.000 description 4
- 229910052708 sodium Inorganic materials 0.000 description 4
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 description 4
- 229910000733 Li alloy Inorganic materials 0.000 description 3
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 3
- 238000000498 ball milling Methods 0.000 description 3
- 239000000084 colloidal system Substances 0.000 description 3
- 239000002131 composite material Substances 0.000 description 3
- 238000007590 electrostatic spraying Methods 0.000 description 3
- 238000005265 energy consumption Methods 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 239000011888 foil Substances 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 239000001989 lithium alloy Substances 0.000 description 3
- 239000002109 single walled nanotube Substances 0.000 description 3
- 238000000967 suction filtration Methods 0.000 description 3
- 229910000528 Na alloy Inorganic materials 0.000 description 2
- OBNDGIHQAIXEAO-UHFFFAOYSA-N [O].[Si] Chemical compound [O].[Si] OBNDGIHQAIXEAO-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910021385 hard carbon Inorganic materials 0.000 description 2
- DCYOBGZUOMKFPA-UHFFFAOYSA-N iron(2+);iron(3+);octadecacyanide Chemical compound [Fe+2].[Fe+2].[Fe+2].[Fe+3].[Fe+3].[Fe+3].[Fe+3].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] DCYOBGZUOMKFPA-UHFFFAOYSA-N 0.000 description 2
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 239000002048 multi walled nanotube Substances 0.000 description 2
- 229960003351 prussian blue Drugs 0.000 description 2
- 239000013225 prussian blue Substances 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 1
- HFCVPDYCRZVZDF-UHFFFAOYSA-N [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O Chemical compound [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O HFCVPDYCRZVZDF-UHFFFAOYSA-N 0.000 description 1
- HMYNUKPKYAKNHH-UHFFFAOYSA-N acetylene;hydrate Chemical compound O.C#C HMYNUKPKYAKNHH-UHFFFAOYSA-N 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 239000003979 granulating agent Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 229910000664 lithium aluminum titanium phosphates (LATP) Inorganic materials 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910021382 natural graphite Inorganic materials 0.000 description 1
- 239000007773 negative electrode material Substances 0.000 description 1
- 229920000447 polyanionic polymer Polymers 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 238000000935 solvent evaporation Methods 0.000 description 1
- 239000002203 sulfidic glass Substances 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 229910000314 transition metal oxide Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
-
- 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
-
- 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
- H01M4/043—Processes of manufacture in general involving compressing or compaction
- H01M4/0435—Rolling or calendering
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides an electrode preparation method, an electrode and a battery, wherein the electrode preparation method comprises the following steps: mixing an insoluble fiberizable adhesive, a soluble adhesive or a dispersible adhesive, a conductive agent and a solvent to obtain a conductive fiber; mixing and granulating the conductive fibers and active substances to obtain electrode powder; extruding the electrode powder into a film to form an electrode film; and connecting the electrode membrane with a current collector to form an electrode. According to the electrode preparation method, the conductive fibers are prepared before the electrode membrane is formed, so that the film forming strength and the conductivity of the electrode membrane can be improved by the conductive fibers, and the electrode manufacturing yield can be improved.
Description
Technical Field
The present invention relates to the field of battery production technology, and more particularly, to an electrode preparation method, an electrode prepared by the electrode preparation method, and a battery including the electrode.
Background
The battery electrode sheet processing process may be classified into a wet electrode process and a dry electrode process according to whether a solvent is used. In the wet electrode process, a large amount of solvent is contained in the liquid slurry, the energy consumption is huge due to the fact that the solvent is heated and dried, and meanwhile, the production process of the pole piece needs to wait for solvent evaporation, so that the production efficiency is low. In the actual production process, the self-supporting electrode membrane is often manufactured in a rolling mode, the strength of the self-supporting electrode membrane formed in the rolling mode is very critical, and the defects of easiness in cracking, hole breaking and the like of the self-supporting membrane are caused by the lower membrane strength, so that the manufacturing yield of the dry electrode is reduced.
As shown in fig. 2, in the conventional dry electrode manufacturing method, an insoluble fiberizable binder is fibrillated during shear mixing to form a fiber network 10, and this fiber network 10 entangles and supports electrode powder and conductive agent particles. However, the conductive agent particles tend to be smaller, and when the amount of the conductive agent particles added is greater, the conductive agent particles are more likely to leak out of the fiber network 10, thereby reducing the strength of the electrode membrane and even failing to form a film, and at the same time, the finer binder fibers tend to also bring about lower self-supporting electrode membrane strength. When the amount of the conductive agent particles added is small, the conductivity of the electrode is insufficient, and it is difficult to support the application of the high-rate charge-discharge battery in particular.
Disclosure of Invention
The first object of the present invention is to provide a new technical solution of an electrode preparation method, which at least can solve the technical problem of low yield of the existing electrode manufacture.
A second object of the present invention is to provide an electrode made by the above electrode preparation method.
A third object of the present invention is to provide a battery comprising the above electrode.
According to a first aspect of the present invention, there is provided a method of preparing an electrode comprising the steps of:
mixing an insoluble fiberizable adhesive, a soluble adhesive or a dispersible adhesive, a conductive agent and a solvent to obtain a conductive fiber; mixing and granulating the conductive fibers and active substances to obtain electrode powder; extruding the electrode powder into a film to form an electrode film; and connecting the electrode membrane with a current collector to form an electrode.
Optionally, the step of mixing the insoluble fiberizable binder, the soluble binder or the dispersible binder, the conductive agent, and the solvent to obtain the conductive fiber comprises: carrying out fibrosis treatment on the insoluble fiberizable adhesive to obtain a fiberized material; mixing the soluble adhesive or the dispersion adhesive with the solvent to prepare glue; mixing the fiberizing material, the conductive agent and the glue, wherein the fiberizing material and the conductive agent are bonded through the glue to form a mixture of conductive fibers and a solution; separating the solution in the mixture to obtain the conductive fiber.
Optionally, the step of mixing the insoluble fiberizable binder, the soluble binder or the dispersible binder, the conductive agent, and the solvent to obtain the conductive fiber comprises: mixing the soluble adhesive or the dispersion adhesive with the solvent to prepare glue; shearing and mixing the insoluble fiberizable adhesive, the conductive agent and the glue, wherein the conductive insoluble fiberizable adhesive forms a fiberized material in the shearing and mixing process, and the fiberized material and the conductive agent are bonded through the glue to form a mixture of conductive fibers and a solution; separating the solution in the mixture to obtain the conductive fiber.
Optionally, the weight content of solids in the mixture is 5% -75%.
Optionally, the step of separating the solution in the mixture to obtain the conductive fiber includes: solid-liquid separation is carried out on the mixture to obtain primary conductive fibers; and drying the primary conductive fiber to obtain the conductive fiber, wherein the drying temperature of the primary conductive fiber is 60-180 ℃, and the liquid content of the conductive fiber after drying is lower than 0.2%.
Optionally, the weight ratio of the insoluble fiberizable adhesive to the conductive agent in the conductive fiber is 0.5-2:1, and the weight ratio of the conductive agent to the soluble adhesive is 1-20:1.
Optionally, the insoluble fiberizable adhesive includes at least one selected from polytetrafluoroethylene resin, tetrafluoroethylene and perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene and hexafluoropropylene copolymer, and polytrifluoroethylene resin, and the soluble adhesive or the dispersion adhesive includes at least one selected from polyvinylidene fluoride, polyvinylidene fluoride and hexafluoropropylene copolymer, carboxymethyl cellulose, polyacrylic acid, polyacrylate, polyacrylonitrile, polymethacrylate adhesive, rubber solution type adhesive, polyacrylic acid emulsion, polyacrylate emulsion, polyacrylonitrile emulsion, polymethacrylate emulsion, and rubber emulsion type adhesive.
Optionally, the conductive agent includes at least one of carbon nanotubes, graphite-based conductive agents, conductive carbon black, ketjen black, acetylene black, graphene, and carbon fibers.
Optionally, the solvent comprises at least one of water, halogenated hydrocarbon solvent with 1-3 carbon atoms, alkane compound with 5-8 carbon atoms, pyrrolidone compound with 5-8 carbon atoms, amide compound with 3-6 carbon atoms, carboxylic acid ester with 3-6 carbon atoms, carbonic acid ester with 3-6 carbon atoms, ketone compound with 3-6 carbon atoms, alcohol compound with 1-5 carbon atoms and ether compound with 4-8 carbon atoms.
Optionally, the weight ratio of the insoluble fiberizable binder in the conductive fiber is 20% -60%, the weight ratio of the soluble binder or the dispersive binder is 0-20%, 0% is not contained, and the weight ratio of the conductive agent is 20% -60%.
Optionally, the step of mixing and granulating the conductive fiber and the active substance to obtain electrode powder comprises the following steps: crushing the conductive fibers to form conductive fiber powder, wherein the median particle size of the conductive fiber powder is 5-1000 meshes; and mixing and granulating the conductive fiber powder and the active substance in an environment of 5-120 ℃ to obtain the electrode powder.
Optionally, the diameter of the conductive fiber in the electrode is 0.5 μm to 50 μm, the length is 30 μm to 500 μm, and the length-diameter ratio is 3 to 300:1.
Optionally, the active material accounts for 80-99% of the weight of the electrode powder, and the conductive fiber accounts for 1-20% of the weight of the electrode powder; the active material comprises 0-20% of solid electrolyte by weight of the electrode powder, wherein the solid electrolyte is sulfide.
Optionally, in the step of extruding the electrode powder into a film to form an electrode film, the thickness of the electrode film is 80-180 μm, the MD tensile strength is greater than or equal to 0.5MPa, the TD tensile strength is greater than or equal to 0.17MPa, and the resistivity is less than or equal to 20Ω & cm
Optionally, the electrode powder is extruded into a film by a roller press, the roller press at least comprises two press rollers, the linear speed ratio of the roller surfaces of the two press rollers is 1:1-1:16, and the temperature of the roller surfaces is 50-250 ℃.
Optionally, the step of connecting the electrode membrane with a current collector to form an electrode includes: a conductive adhesive layer is arranged on at least one of the electrode membrane and the current collector; and bonding the electrode membrane and the current collector through the conductive adhesive layer to form the electrode.
Optionally, the conductive adhesive layer is coated on the current collector, and the thickness of the conductive adhesive layer is 0.5-3 μm; the electrode membrane, the conductive adhesive layer and the current collector are bonded through hot pressing, the temperature during hot pressing is 50-250 ℃, and the line pressure during hot pressing is 0.5-80 tons of force/meter.
According to a second aspect of the present invention there is provided an electrode made according to the electrode preparation method described above.
According to a third aspect of the present invention there is provided a battery comprising an electrode as described above.
According to the electrode preparation method, the conductive fibers are prepared before the electrode membrane is formed, so that the film forming strength and the conductivity of the electrode membrane can be improved, the electrode manufacturing yield can be improved, compared with the existing wet electrode process, only the solvent is used in the process of preparing the conductive fibers, but not the solvent is used when the conductive fibers account for most of active substances, the corresponding amount of the used solvent is smaller, meanwhile, the process after the conductive fibers are prepared does not contain the solvent, the suitability advantage of the dry electrode process is still achieved, and the production efficiency is higher; compared with the existing dry electrode process, the electrode membrane with high film forming strength and good conductivity can be formed, the electrode manufacturing yield can be improved, and the production efficiency of the electrode can be ensured.
Other features of the present invention and its advantages will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.
FIG. 1 is a flow chart of a method of preparing an electrode according to one embodiment of the present invention;
FIG. 2 is a schematic structural diagram of an electrode membrane material of an electrode prepared by a conventional dry electrode process;
fig. 3 is a schematic structural view of an electrode membrane material of an electrode according to one embodiment provided by the present invention.
Reference numerals
A fiber network 10;
a conductive agent 20;
an active material 30;
conductive fiber powder 40.
Detailed Description
Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.
The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.
In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.
The method for preparing an electrode according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1, the electrode preparation method according to an embodiment of the present invention includes the steps of: mixing an insoluble fiberizable adhesive, a soluble adhesive or a dispersible adhesive, a conductive agent 20, and a solvent to obtain a conductive fiber; mixing and granulating the conductive fibers and the active substances 30 to obtain electrode powder; extruding the electrode powder into a film to form an electrode film; and connecting the electrode membrane with a current collector to form an electrode.
Specifically, the insoluble fiberizable adhesive, the soluble adhesive or the dispersible adhesive, the conductive agent 20 and the solvent may be mixed first, the mixing order of the four may be any combination of the order, the mixing manner may be at least one of ball milling, colloid milling, sand milling, high-speed stirring, planetary stirring, ultrasonic dispersion, high-pressure fluid milling, and the conductive fiber may be obtained after mixing. The conductive fibers and active material 30 may then be mixed and granulated to obtain an electrode powder. Then, the electrode powder can be put into a film forming device, and the film forming device can extrude the electrode powder into a film to obtain the electrode film. And finally, connecting the electrode membrane with a current collector to obtain the electrode. The preparation process is simple, and the prepared electrode has high strength and conductivity and has the advantages of the existing dry electrode process.
The type of the active material 30 is not particularly limited, and one skilled in the art may select according to the application scenario of the electrode sheet and the performance requirements of the positive electrode sheet/negative electrode sheet. The active material 30 is a common positive and negative electrode material of lithium/sodium ion battery, such as lithium cobaltate, lithium manganate, lithium nickel cobalt manganate, lithium iron phosphate, sodium-containing layered transition metal oxide, sodium-based Prussian blue-based material, polyanion sodium salt, natural graphite, artificial graphite, mesophase carbon microsphere, soft carbon, hard carbon, silicon oxide, composite silicon carbon material, lithium titanate, metallic lithium and its composite, lithium alloy, metallic material capable of forming lithium alloy, metallic sodium and its composite, sodium alloy, metallic material capable of forming sodium alloy, etc.
Further, the electrode preparation method provided by the invention still has the advantage of suitability of a dry electrode when using some solvent-sensitive active materials such as metallic lithium or lithium alloys or solvent-sensitive solid electrolytes such as sulfide solid electrolytes.
Therefore, according to the electrode preparation method provided by the embodiment of the invention, the conductive fiber is prepared before the electrode membrane is formed, so that the film forming strength and conductivity of the electrode membrane can be improved, and the electrode manufacturing yield can be improved; compared with the existing dry electrode process, the electrode membrane with high film forming strength and good conductivity can be formed, the electrode manufacturing yield can be improved, and the production efficiency of the electrode can be ensured.
According to some embodiments of the present invention, the step of mixing the insoluble fiberizable binder, the soluble binder or the dispersible binder, the conductive agent 20, and the solvent to obtain the conductive fiber comprises: carrying out fibrosis treatment on the insoluble fiberizable adhesive to obtain a fiberized material; mixing a fiberizing material, a soluble adhesive or a dispersible adhesive, a conductive agent 20 and a solvent, wherein the fiberizing material and the conductive agent 20 are bonded through the soluble adhesive or the dispersible adhesive to form a mixture of conductive fibers and a solution; and separating the solution in the mixture to obtain the conductive fiber.
In some embodiments of the present invention, the step of mixing the insoluble fiberizable binder, the soluble binder or the dispersible binder, the conductive agent 20, and the solvent to obtain the conductive fiber comprises: carrying out fibrosis treatment on the insoluble fiberizable adhesive to obtain a fiberized material; mixing a soluble adhesive or a dispersible adhesive with a solvent to prepare glue; mixing a fiberizing material, a conductive agent 20 and glue, wherein the fiberizing material and the conductive agent 20 are bonded through the glue to form a mixture of conductive fibers and a solution; and separating the solution in the mixture to obtain the conductive fiber.
That is, the insoluble fiberizable adhesive is sheared first, the insoluble fiberizable adhesive is fibrillated during shearing so that the insoluble fiberizable adhesive forms a fiberized material, then the soluble adhesive or the dispersion-type adhesive is uniformly mixed with the solvent to prepare glue, and after the soluble adhesive or the dispersion-type adhesive is uniformly mixed with the solvent, the fiberized material and the conductive agent 20 are mixed with the glue, wherein the mixing mode can be at least one of ball milling, colloid milling, sand milling, high-speed stirring, planetary stirring, ultrasonic dispersion and high-pressure fluid milling. In the mixing process, the conductive agent 20 can be uniformly adhered to the surface of the fiberized material under the action of glue to form conductive fibers, at this time, the conductive fibers and the rest of the solution form a mixture, and finally, the solution in the mixture is separated to obtain the required conductive fibers.
By adopting the preparation method of the conductive fiber, the solution can be recovered, and all the solution is volatilized as in the traditional wet electrode, so that the energy consumption is lower, and the economical efficiency is still higher; and the soluble adhesive or the dispersion adhesive is mixed with the solvent more uniformly, so that the uniformity of the conductive agent 20 on the conductive fiber can be ensured.
When the insoluble fiberizable adhesive is in a fiberized state, the step of fiberizing the insoluble fiberizable adhesive may be omitted.
According to some embodiments of the present invention, the step of mixing the insoluble fiberizable binder, the soluble binder or the dispersible binder, the conductive agent 20, and the solvent to obtain the conductive fiber comprises: shearing and mixing an insoluble fiberizable adhesive, a soluble adhesive or a dispersible adhesive, a conductive agent 20 and a solvent, wherein the insoluble fiberizable adhesive forms a fiberized material in the shearing and mixing process, and the fiberized material and the conductive agent 20 are bonded through the soluble adhesive or the dispersible adhesive to form a mixture of conductive fibers and a solution; and separating the solution in the mixture to obtain the conductive fiber.
In some embodiments of the present invention, the step of mixing the insoluble fiberizable binder, the soluble binder or the dispersible binder, the conductive agent 20, and the solvent to obtain the conductive fiber comprises: mixing a soluble adhesive or a dispersible adhesive with a solvent to prepare glue; shearing and mixing an insoluble fiberizable adhesive, a conductive agent 20 and glue, wherein the conductive insoluble fiberizable adhesive forms a fiberized material in the shearing and mixing process, and the fiberized material and the conductive agent 20 are bonded through the glue to form a mixture of conductive fibers and a solution; and separating the solution in the mixture to obtain the conductive fiber.
That is, the soluble adhesive or the dispersion adhesive may be mixed with the solvent uniformly to prepare the glue, and the mixing manner may be at least one of ball milling, colloid milling, sand milling, high-speed stirring, planetary stirring, ultrasonic dispersion, and high-pressure fluid milling, and after the soluble adhesive or the dispersion adhesive is mixed with the solvent uniformly, the insoluble fiberizable adhesive and the conductive agent 20 are sheared and mixed with the glue. The fiberizable binder fibrillates during the shear mixing to form a fibrillated mass. The conductive agent 20 can be uniformly adhered to the surface of the fiberized material under the action of the glue to form conductive fibers, at this time, the conductive fibers and the rest of the solution form a mixture, and finally, the solution in the mixture is separated to obtain the required conductive fibers.
By adopting the preparation method of the conductive fiber, the solution can be recovered, and all the solution is volatilized as in the traditional wet electrode, so that the energy consumption is lower, and the economical efficiency is still higher; and the soluble adhesive or the dispersion adhesive is mixed with the solvent more uniformly, so that the uniformity of the conductive agent 20 on the conductive fiber can be ensured.
According to some embodiments of the invention, the weight content of solids in the mixture of conductive fibers and solution is 5% to 75%.
In some embodiments of the invention, the step of separating the solution in the mixture to obtain the conductive fibers comprises: solid-liquid separation is carried out on the mixture to obtain primary conductive fibers; and drying the primary conductive fiber to obtain the conductive fiber, wherein the drying temperature of the primary conductive fiber is 60-180 ℃, and the liquid content of the dried conductive fiber is lower than 0.2%.
That is, the solution in the mixture is first separated, the separation mode of the separated solution can be at least one of gravity sedimentation, centrifugation, centrifugal filtration, press filtration and suction filtration, the primary conductive fiber with larger liquid content can be obtained after the solution separation, and finally the primary conductive fiber can be dried by air blast drying to obtain the required conductive fiber, wherein the air blast drying temperature is 60-180 ℃, and the liquid content in the conductive fiber obtained after the primary conductive fiber is dried is lower than 0.2%.
In this embodiment, the dried conductive fiber is convenient to be uniformly mixed with the active material 30, and the occurrence of the agglomeration phenomenon can be avoided.
According to some embodiments of the present invention, the weight ratio of insoluble fiberizable binder to conductive agent 20 is 0.5-2:1, and the weight ratio of conductive agent 20 to soluble binder is 1-20:1.
Optionally, the insoluble fiberizable binder is a fluororesin.
In some embodiments of the present invention, the insoluble fiberizable adhesive comprises at least one selected from the group consisting of polytetrafluoroethylene resins, tetrafluoroethylene and perfluoroalkyl vinyl ether copolymers, tetrafluoroethylene and hexafluoropropylene copolymers, and polytrifluoroethylene resins, and the soluble adhesive or dispersion adhesive comprises at least one of polyvinylidene fluoride, polyvinylidene fluoride and hexafluoropropylene copolymers, carboxymethyl celluloses, polyacrylics, polyacrylates, polyacrylonitriles, polymethacrylates adhesives, rubber solution adhesives, polyacrylic acid emulsions, polyacrylate emulsions, polyacrylonitrile emulsions, polymethacrylate emulsions, and rubber emulsion adhesives.
According to some embodiments of the present invention, the conductive agent 20 includes at least one of carbon nanotubes, graphite-based conductive agents, conductive carbon black, ketjen black, acetylene black, graphene, and carbon fibers. The carbon nanotubes may be multi-walled carbon nanotubes or single-walled carbon nanotubes, and the graphite-based conductive agent may be conductive graphite.
In this embodiment, the conductive agent 20 may be one or more of the above materials, and the conductivity of the pole piece may be ensured.
In some embodiments of the present invention, the solvent comprises at least one of water, a halogenated hydrocarbon solvent having 1 to 3 carbon atoms, an alkane compound having 5 to 8 carbon atoms, a pyrrolidone compound having 5 to 8 carbon atoms, an amide compound having 3 to 6 carbon atoms, a carboxylic acid ester having 3 to 6 carbon atoms, a carbonate having 3 to 6 carbon atoms, a ketone compound having 3 to 6 carbon atoms, an alcohol compound having 1 to 5 carbon atoms, and an ether compound having 4 to 8 carbon atoms.
The solvent is matched with the corresponding soluble adhesive, the soluble adhesive can be dissolved in the corresponding solvent, for example, polyvinylidene fluoride is selected as the soluble adhesive, and N-methyl pyrrolidone or NN dimethylformamide is selected as the solvent. The dispersion type adhesive can be emulsion type, the emulsion type dispersible adhesive is required to be compatible with the solvent and not delaminate or precipitate, for example, the dispersion type adhesive is an aqueous emulsion of polyacrylic acid, and the solvent can be water or ethanol.
In the embodiment of the present invention, the types of the insoluble fibrous adhesive, the soluble adhesive or the dispersion adhesive, and the conductive agent 20 are not particularly limited, and may be selected by those skilled in the art according to the application scenario of the electrode sheet, performance requirements of the positive electrode sheet/negative electrode sheet, and the like.
In some embodiments of the present invention, the conductive fibers have an insoluble fiberizable binder weight ratio of 20% to 60%, a soluble binder or a dispersible binder weight ratio of 0% to 20%, no 0%, and a conductive agent 20 weight ratio of 20% to 60%.
According to some embodiments of the invention, the step of granulating the conductive fibers with the active material 30 to obtain an electrode powder comprises: crushing conductive fibers to form conductive fiber powder 40, wherein the median particle size of the conductive fiber powder 40 is 5-1000 meshes; and mixing and granulating the conductive fiber powder 40 and the active substance 30 at the temperature of 5-120 ℃ to obtain electrode powder.
That is, the conductive fibers are first pulverized into conductive fiber powder 40 having a median particle diameter of 5 to 1000 mesh, and the pulverizing step may be a toothed roll type crusher, a shear type crusher, a swing type granulator, a rotary type granulator, a mechanical shear, an extrusion screen, or may be air-flow pulverizing classification. The electrode powder is obtained after the conductive fiber is crushed, mixed and granulated with the active substance 30 in the environment of 5-120 ℃, and the mixed granulating procedure can be one or more of high-speed shearing and dispersing, double-screw shearing and internal mixer shearing.
By adopting the electrode powder preparation method, the particle size of the conductive fiber powder 40 is convenient to control, and the crushed conductive fiber is convenient to uniformly mix with the active substance 30.
According to some embodiments of the invention, the conductive fibers have a diameter of 0.5 μm to 50 μm and a length of 30 μm to 500 μm and an aspect ratio of 3 to 300:1.
That is, the conductive fiber can be processed into particles with a diameter of 0.5 μm to 50 μm and a length of 30 μm to 500 μm according to actual requirements during preparation, wherein the ratio of the length of the conductive fiber to the diameter is 3 to 300:1, and specific values can be determined according to the strength and the conductivity required by the electrode membrane, and are not described in detail in the embodiment.
In some embodiments of the invention, the active material 30 comprises 80% to 99% by weight of the electrode powder and the conductive fiber comprises 1% to 20% by weight of the electrode powder.
According to some embodiments of the invention, the active material 30 comprises 0-20% by weight of solid electrolyte based on the weight of the electrode powder.
In some embodiments of the invention, the solid state electrolyte is a sulfide.
That is, when the solid electrolyte is sulfide, the electrode preparation method provided by the invention still has the advantage of suitability of a dry electrode.
According to some embodiments of the present invention, in the step of extruding the electrode powder into a film, the electrode film has a thickness of 80 μm to 180 μm, an MD tensile strength of 0.5MPa or more, a TD tensile strength of 0.17MPa or more, and a resistivity of 20Ω·cm or less.
That is, the electrode membrane preparation method provided by the invention can be used for preparing the electrode membrane with high film forming strength and good conductivity.
According to some specific embodiments of the invention, the electrode powder is extruded into a film by a roll press, wherein the roll press at least comprises two press rolls, the linear speed ratio of the roll surfaces of the two press rolls is between 1:1 and 1:16, and the temperature of the roll surfaces is between 50 ℃ and 250 ℃.
That is, the film forming apparatus may be a roll press including at least two press rolls rotatable about their own axes, and a distance between roll surfaces of the two press rolls is adjustable. When electrode powder is extruded to form a film, the linear speed ratio of the roller surfaces of the two pressing rollers can be 1:1-1:16, the roller surface temperature can be 50-250 ℃, specific numerical values can be determined according to the types of materials, and the embodiment is not repeated.
According to some embodiments of the invention, the step of extruding the electrode powder into a film, the step of forming an electrode membrane comprises: extruding the electrode powder into a film to obtain a primary film; the primary membrane is thinned to obtain an electrode membrane having a predetermined weight and a predetermined thickness.
That is, the electrode powder is first put into a roll press, the roll press can extrude the electrode powder into a film to obtain a thicker primary film, and finally the primary film can be put into the roll press for thinning according to a preset thickness and a preset weight. The primary film sheet may be pressed one or more times under the influence of a roll press to an electrode film sheet of a predetermined weight and a predetermined thickness.
In some embodiments of the invention, the step of connecting the electrode membrane to the current collector to form an electrode comprises: a conductive adhesive layer is arranged on at least one of the electrode membrane and the current collector; and bonding the electrode membrane and the current collector through a conductive adhesive layer to form the electrode.
Specifically, firstly, cutting an electrode membrane into a required electrode shape, then, coating conductive glue on any side of the electrode membrane or any side of a current collector to form a conductive glue layer on the surface of the conductive glue layer, and finally, bonding the electrode membrane and the current collector together through the conductive glue layer to form the electrode.
The electrode membrane and the current collector adopt the connecting method, the operation is convenient, and the connecting effect of the electrode membrane and the current collector is good.
Preferably, one surface of the electrode membrane is provided with a conductive adhesive layer, wherein the conductive adhesive layer comprises a conductive agent 20 and a thermoplastic polymer.
In some embodiments of the invention, the current collector is coated with a conductive adhesive layer having a thickness of 0.5 μm to 3 μm; the electrode membrane, the conductive adhesive layer and the current collector are bonded through hot pressing, the temperature during hot pressing is 50-250 ℃, the line pressure during hot pressing is 0.5-80 tons of force/meter, and the pole piece can be obtained after hot pressing and rolling.
The electrode preparation method of the present invention will be specifically described with reference to the following examples.
Example 1
Firstly, proportioning polytetrafluoroethylene, PVDF, ketjen black and NN dimethylformamide according to the weight ratio of 50:16:34:300, and shearing and mixing by using a sand mill to obtain a uniform mixture of conductive fibers and a solution;
secondly, separating the conductive fibers from the solution by a centrifugal filtration method, drying the solution by blowing at 80 ℃ for 2 hours, and crushing the solution by a shearing crusher to obtain conductive fiber powder 40 with the particle size of about 200 meshes;
then, adding the NCM ternary material and the conductive fiber powder 40 into high-shear mixing equipment according to the weight ratio of 94:6, shearing, mixing and granulating, wherein the temperature is controlled to be 80 ℃ for high-speed dispersion, and then 15 ℃ for low-speed granulation, so that uniform electrode powder is obtained;
and then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:2, the heating temperature of powder before rolling and the roller surface temperature are 100 ℃, and the self-supporting electrode film A1 is obtained after film forming.
Finally, the mixture of PVDF and conductive carbon black, namely conductive glue, is sprayed on an aluminum foil current collector with the diameter of 12 mu m in an electrostatic spraying mode, and is heated and solidified. Unreeling the electrode film A1, and thinning to 113 μm with surface density of 384g/m 2 Cutting into corresponding width, and then carrying out hot pressing lamination with a current collector sprayed with a conductive adhesive layer, wherein the hot pressing temperature is 180 ℃. And finally, winding to obtain the electrode plate B1.
Comparative example one
Firstly, adding NCM ternary material, ketjen black and polytetrafluoroethylene powder into high-shear mixing equipment according to the weight ratio of 94:2:4, shearing, mixing and granulating, wherein the temperature is controlled to be 80 ℃ for high-speed dispersion, and then granulating at 15 ℃ for low speed, so as to obtain uniform electrode powder;
finally, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:2, the heating temperature of powder before rolling and the roller surface temperature are 100 ℃, and as a result, continuous film forming cannot be carried out.
Example two
Firstly, proportioning polytetrafluoroethylene, PVDF, ketjen black and NN dimethylformamide according to the weight ratio of 50:16:34:300, and shearing and mixing by using a sand mill to obtain a uniform mixture of conductive fibers and a solution;
secondly, separating the conductive fibers from the solution by a centrifugal filtration method, drying the conductive fibers for 2 hours at the temperature of 80 ℃ by blowing, and crushing the conductive fibers by a shearing crusher to obtain conductive fiber powder 40 with the particle size of about 200 meshes;
Then, adding the NCM ternary material and the conductive fiber powder 40 into high-shear mixing equipment according to the weight ratio of 97:3, shearing, mixing and granulating, wherein the temperature is controlled to be 80 ℃ for high-speed dispersion, and then 15 ℃ for low-speed granulation, so that uniform electrode powder is obtained;
and then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:2, the heating temperature of powder before rolling and the roller surface temperature are 100 ℃, and the self-supporting electrode film A2 is obtained after film forming.
Finally, the mixture of PVDF and conductive carbon black, namely conductive glue, is sprayed on an aluminum foil current collector with the diameter of 12 mu m in an electrostatic spraying mode, and is heated and solidified. Unreeling the electrode film A2, and thinning to 110 μm with the surface density of 374g/m 2 Cutting into corresponding width, and then carrying out hot pressing lamination with a current collector sprayed with a conductive adhesive layer, wherein the hot pressing temperature is 180 ℃. And finally, winding to obtain the electrode plate B2.
Comparative example two
Firstly, adding NCM ternary material, ketjen black and polytetrafluoroethylene powder into high-shear mixing equipment according to the weight ratio of 97:0.5:2.5, shearing, mixing and granulating, wherein the temperature is controlled to be 80 ℃ for high-speed dispersion, and then 15 ℃ for low-speed granulation, so as to obtain uniform electrode powder;
And then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:2, the heating temperature of powder before rolling and the roller surface temperature are 100 ℃, and the self-supporting electrode film C2 is obtained after film forming.
Finally, the mixture of PVDF and conductive carbon black, namely conductive glue, is sprayed on an aluminum foil current collector with the diameter of 12 mu m in an electrostatic spraying mode, and is heated and solidified. Unreeling the electrode film C2, and thinning to 115 μm with surface density 391g/m 2 Cutting into corresponding width, and then carrying out hot pressing lamination with a current collector sprayed with a conductive adhesive layer, wherein the hot pressing temperature is 180 ℃. And finally, winding to obtain the electrode plate D2.
Example III
Firstly, proportioning polytetrafluoroethylene, PVDF, multi-wall carbon nano tubes and N-methyl pyrrolidone according to the weight ratio of 50:10:40:200, and shearing and mixing by using a ball mill to obtain a uniform mixture of conductive fibers and a solution;
secondly, separating the conductive fibers from the solution by a filter pressing method, drying the solution by blowing at 120 ℃ for 4 hours, and crushing the solution by an air flow crusher to obtain conductive fiber powder 40 with the particle size of about 400 meshes;
then, adding the NCM ternary material, the LATP solid electrolyte and the conductive fiber powder 40 into double-screw mixing equipment according to the weight ratio of 86:10:4, shearing, mixing and granulating, and controlling the temperature to 130 ℃ to obtain uniform electrode powder;
And then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:1.6, the heating temperature of powder before rolling and the roller surface temperature are 130 ℃, and the self-supporting electrode film A3 is obtained after film forming.
Finally, unreeling the electrode film A3, thinning to 100 μm, and the surface density is 320g/m 2 Cutting into corresponding widths, and then carrying out hot-pressing lamination with an aluminum current collector coated with a PVDF-based conductive adhesive layer, wherein the hot-pressing temperature is 160 ℃. And finally, winding to obtain the electrode plate B3.
Example IV
Firstly, dissolving PVDF and NN dimethylformamide according to the weight ratio of 5:95 to prepare glue with the solid content of 5%, adding acetylene black into the glue, putting the glue into high-speed dispersing equipment to carry out high-speed stirring, wherein the weight ratio of the acetylene black to the glue is 40:300, adding polytetrafluoroethylene powder after uniformly stirring, and the weight ratio of the polytetrafluoroethylene to the glue is 45:340, and uniformly mixing to obtain a uniform mixture of conductive fibers and solution;
secondly, separating the conductive fibers from the solution by a suction filtration method, drying the solution by blowing air at 140 ℃ for 3 hours, and crushing the solution by a swing granulating agent to obtain conductive fiber powder 40 with the particle size of about 50 meshes;
then, adding lithium iron phosphate and conductive fiber powder 40 into mixing equipment of an internal mixer according to the weight ratio of 94:6, shearing and mixing, and granulating by a rotary granulator, wherein the temperature is controlled to be 120 ℃ to obtain uniform electrode powder;
And then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:6, the heating temperature of powder before rolling and the roller surface temperature are 160 ℃, and the self-supporting electrode film A4 is obtained after film forming.
Finally, the electrode film A4 is unreeled and thinned to 140 mu m, and the surface density is 364g/m 2 Cutting into corresponding widths, and then carrying out hot-pressing lamination with an aluminum current collector coated with a PAA-based conductive adhesive layer, wherein the hot-pressing temperature is 150 ℃. And finally, winding to obtain the electrode plate B4.
Example five
Firstly, proportioning polytetrafluoroethylene, PAA-Na, conductive carbon black and water according to the weight ratio of 42:18:40:100, and mixing by using ultrasonic dispersion to obtain a uniform mixture of conductive fibers and solution;
secondly, separating the conductive fibers from the solution by a centrifugal filtration method, drying the solution by blowing air at the temperature of 100 ℃ for 6 hours, and crushing the solution by a shearing crusher to obtain conductive fiber powder 40 with the particle size of about 50 meshes;
then, adding the sodium-based Prussian blue material and the conductive fiber powder 40 into high-shear mixing equipment according to the weight ratio of 95:5, shearing, mixing and granulating, wherein the temperature is controlled to be firstly 80 ℃ for high-speed dispersion, and then 15 ℃ for low-speed granulation, so as to obtain uniform electrode powder;
And then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:3, the heating temperature of powder before rolling and the roller surface temperature are 120 ℃, and the self-supporting electrode film A5 is obtained after film forming.
Finally, unreeling the electrode film A5, thinning to 200 mu m, and enabling the surface density to be 340g/m 2 Cutting into corresponding width, and then carrying out hot-pressing lamination with an aluminum current collector coated with a PAA-based conductive adhesive layer, wherein the hot-pressing temperature is 180 ℃. And finally, winding to obtain the electrode plate B5.
Example six
Firstly, proportioning polytetrafluoroethylene, PVDF, conductive carbon black and NN dimethylformamide according to the weight ratio of 45:20:25:100, and shearing and mixing by using a sand mill to obtain a uniform mixture of conductive fibers and solution;
secondly, separating the conductive fibers from the solution by a centrifugal filtration method, drying the solution by blowing at 80 ℃ for 2 hours, and crushing the solution by a shearing crusher to obtain conductive fiber powder 40 with the particle size of about 100 meshes;
then, adding the artificial graphite and the conductive fiber powder 40 into high-shear mixing equipment according to the weight ratio of 98:2, shearing, mixing and granulating, and controlling the temperature to 140 ℃ to obtain uniform electrode powder;
And then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:1, the heating temperature of powder before rolling and the roller surface temperature are 140 ℃, and the self-supporting electrode film A6 is obtained after film forming.
Finally, the electrode film A6 is unreeled and thinned to 80 mu m, and the surface density is 132g/m 2 Cutting into corresponding width, and then carrying out hot-pressing lamination with a copper current collector coated with a PAA-based conductive adhesive layer, wherein the hot-pressing temperature is 120 ℃. And finally, winding to obtain the electrode plate B6.
Example seven
Firstly, proportioning polytetrafluoroethylene, PAA-Li, single-walled carbon nanotubes, conductive carbon black and water according to the weight ratio of 50:20:5:25:250, and shearing and mixing by using a ball mill to obtain a uniform mixture of conductive fibers and solution;
secondly, separating the conductive fibers from the solution by a filter pressing method, drying the solution by blowing at 120 ℃ for 2 hours, and crushing the solution by an air flow crusher to obtain conductive fiber powder 40 with the particle size of about 300 meshes;
then, putting the artificial graphite, the silicon oxygen material and the conductive fiber powder 40 into high-shear mixing equipment according to the weight ratio of 90:6:4, shearing and mixing, and granulating, wherein the temperature is controlled to be 70 ℃ to obtain uniform electrode powder;
And then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:4, the heating temperature of powder before rolling and the roller surface temperature are 70 ℃, and the self-supporting electrode film A7 is obtained after film forming.
Finally, unreeling the electrode film A7, thinning to 100 μm, and the surface density is 165g/m 2 Cutting into corresponding widths, and then performing hot-pressing lamination with a copper current collector coated with a PAA-based conductive adhesive layer, wherein the hot-pressing temperature is 160 ℃. Finally, winding to obtain the electrodePole piece B7.
Example eight
Firstly, proportioning polytetrafluoroethylene, CMC-Li, single-walled carbon nano tubes, ketjen black and water according to the weight ratio of 60:15:2:23:150, and shearing and mixing by using planetary stirring to obtain a uniform mixture of conductive fibers and solution;
secondly, separating the conductive fibers from the solution by a suction filtration method, drying the solution by blowing at 120 ℃ for 2 hours, and crushing the solution by an air flow crusher to obtain conductive fiber powder 40 with the particle size of about 500 meshes;
then, putting the artificial graphite, the silicon oxygen material and the conductive fiber powder 40 into high-shear mixing equipment according to the weight ratio of 92:4:4, shearing and mixing, granulating, and controlling the temperature to 90 ℃ to obtain uniform electrode powder;
And then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:2, the heating temperature of powder before rolling and the roller surface temperature are 120 ℃, and the self-supporting electrode film A8 is obtained after film forming.
Finally, the electrode membrane A8 is unreeled, thinned to 140 mu m, cut into corresponding width and then thermally pressed and attached with a copper current collector coated with a PAA-based conductive adhesive layer, wherein the thermal pressing temperature is 170 ℃. And finally, winding to obtain the electrode plate B8.
Example nine
Firstly, proportioning polytetrafluoroethylene, PVDF, conductive carbon black and N-methyl pyrrolidone according to the weight ratio of 70:10:20:100, and shearing and mixing by using a ball mill to obtain a uniform mixture of conductive fibers and solution;
secondly, separating the conductive fibers from the solution by a filter pressing method, drying the solution by blowing at 160 ℃ for 4 hours, and crushing the solution by a rotary granulator to obtain conductive fiber powder 40 with the particle size of about 100 meshes;
then, putting the artificial graphite, the metal lithium powder and the conductive fiber powder 40 into high-shear mixing equipment according to the weight ratio of 92:2:6, shearing and mixing, granulating, and controlling the temperature to be 5 ℃ to obtain uniform electrode powder;
And then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:1, the heating temperature of powder before rolling and the temperature of the roller surface are 140 ℃, and the self-supporting electrode film A9 is obtained after film forming.
Finally, unreeling the electrode film A9, thinning to 120 mu m, and obtaining the surface density of 198g/m 2 Cutting into corresponding widths, and then performing hot-pressing lamination with a copper current collector coated with a PVDF-based conductive adhesive layer, wherein the hot-pressing temperature is 140 ℃. And finally, winding to obtain the electrode plate B9.
Examples ten
Firstly, proportioning polytetrafluoroethylene, PAA emulsion (solid content is 20%), acetylene black and water according to the weight ratio of 45:100:35:320, and dispersing and mixing by using ultrasonic dispersion to obtain a uniform mixture of conductive fibers and solution;
secondly, separating the conductive fibers from the solution by a centrifugal method, drying the solution by blowing at 120 ℃ for 2 hours, and crushing the solution by an air flow crusher to obtain conductive fiber powder 40 with the particle size of about 300 meshes;
then, the hard carbon and the conductive fiber powder 40 are put into a high-shear mixing device according to the weight ratio of 94:6 for shearing mixing and granulating, and the temperature is controlled to be 120 ℃ to obtain uniform electrode powder;
and then, the mixed materials enter film forming equipment to form films, the linear speed ratio of the surfaces of the two rollers is 1:6, the heating temperature of powder before rolling and the roller surface temperature are 140 ℃, and the self-supporting electrode film A10 is obtained after film forming.
Finally, the electrode film A10 is unreeled and thinned to 180 mu m, and the surface density is 234g/m 2 Cutting into corresponding widths, and then carrying out hot-pressing lamination with an aluminum current collector coated with a PAA-based conductive adhesive layer, wherein the hot-pressing temperature is 110 ℃. And finally, winding to obtain the electrode plate B10.
Among them, the strength of the electrode films and the resistivity data of the electrode sheets of the examples and comparative examples are shown in table one.
Table one: data sheet
As can be seen from the comparison of example 1 and comparative example 1, when the content of the conductive agent 20 Ketjen black is about 2%, the electrode containing the conductive fiber can be formed into a film, and the strength is high, the resistivity is low, and the conductivity is good. While the electrode of comparative example 1, which did not use the conductive fiber process, failed to form a film and was broken into pieces.
As can be seen from the comparison of example 2 and comparative example 2, the electrode which does not use the conductive fiber process conventionally can form a film when the content of the conductive agent 20 ketjen black is about 0.5%, the strength is still good, but the resistivity is higher, the conductivity is poor, the electrode is not suitable for the design of the rapid charge and discharge requirement, while the electrode which contains the conductive fiber in example 2 can form a film under the condition of the same active material 30 proportion as that in comparative example 2, the strength is better, the resistivity is lower, and the conductivity is better.
In summary, according to the electrode preparation method provided by the embodiment of the invention, by preparing the conductive fiber before forming the electrode membrane, the conductive fiber can improve the film forming strength and conductivity of the electrode membrane, and can improve the electrode manufacturing yield, compared with the existing wet electrode process, only the solvent is used in the process of preparing the conductive fiber, but the solvent is not used in the process of preparing the active material 30 accounting for the vast majority, and the corresponding amount of the solvent is less, meanwhile, as the process after preparing the conductive fiber does not contain the solvent, the electrode preparation method still has the adaptability advantage of the dry electrode process, and the production efficiency is higher; compared with the existing dry electrode process, the electrode membrane with high film forming strength and good conductivity can be formed, the electrode manufacturing yield can be improved, and the production efficiency of the electrode can be ensured.
As shown in fig. 3, an embodiment of the present invention also provides an electrode manufactured by the electrode manufacturing method of any one of the above embodiments.
In the embodiment, the electrode has good conductivity, can support the use of the high-rate charging and discharging battery, and can improve the performance of the battery.
In some embodiments of the invention, the electrode membrane comprises an active material 30 and conductive fibers having a diameter of 0.5 μm to 50 μm, a length of 30 μm to 500 μm, and an aspect ratio of 3 to 300:1.
Embodiments of the present invention also provide a battery comprising an electrode as described in any of the embodiments above.
While certain specific embodiments of the invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.
Claims (17)
1. A method of preparing an electrode, comprising the steps of:
mixing an insoluble fiberizable adhesive, a soluble adhesive or a dispersible adhesive, a conductive agent and a solvent to obtain a conductive fiber;
mixing and granulating the conductive fibers and active substances to obtain electrode powder;
extruding the electrode powder into a film to form an electrode film;
and connecting the electrode membrane with a current collector to form an electrode.
2. The method of manufacturing an electrode according to claim 1, wherein the step of mixing an insoluble fiberizable binder, a soluble binder or a dispersible binder, a conductive agent, and a solvent to obtain the conductive fiber comprises:
Carrying out fibrosis treatment on the insoluble fiberizable adhesive to obtain a fiberized material;
mixing the soluble adhesive or the dispersion adhesive with the solvent to prepare glue;
mixing the fiberizing material, the conductive agent and the glue, wherein the fiberizing material and the conductive agent are bonded through the glue to form a mixture of conductive fibers and a solution;
separating the solution in the mixture to obtain the conductive fiber.
3. The method of manufacturing an electrode according to claim 1, wherein the step of mixing an insoluble fiberizable binder, a soluble binder or a dispersible binder, a conductive agent, and a solvent to obtain the conductive fiber comprises:
mixing the soluble adhesive or the dispersion adhesive with the solvent to prepare glue;
shearing and mixing the insoluble fiberizable adhesive, the conductive agent and the glue, wherein the conductive insoluble fiberizable adhesive forms a fiberized material in the shearing and mixing process, and the fiberized material and the conductive agent are bonded through the glue to form a mixture of conductive fibers and a solution;
separating the solution in the mixture to obtain the conductive fiber.
4. A method of preparing an electrode according to claim 2 or claim 3, wherein the solids content of the mixture is from 5% to 75% by weight.
5. A method of preparing an electrode according to claim 2 or 3, wherein the step of separating the solution in the mixture to obtain the conductive fibers comprises:
solid-liquid separation is carried out on the mixture to obtain primary conductive fibers;
and drying the primary conductive fiber to obtain the conductive fiber, wherein the drying temperature of the primary conductive fiber is 60-180 ℃, and the liquid content of the conductive fiber after drying is lower than 0.2%.
6. The method of manufacturing an electrode according to claim 1, wherein the weight ratio of the insoluble fiberizable binder to the conductive agent in the conductive fiber is 0.5 to 2:1, and the weight ratio of the conductive agent to the soluble binder is 1 to 20:1.
7. The method for producing an electrode according to claim 1, wherein the insoluble fiberizable adhesive comprises at least one selected from polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and polytrifluoroethylene resin, and the soluble adhesive or the dispersion adhesive comprises at least one selected from polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, carboxymethyl cellulose-based adhesive, polyacrylic acid-based adhesive, polyacrylate-based adhesive, polyacrylonitrile-based adhesive, polymethacrylate-based adhesive, rubber solution-based adhesive, polyacrylic acid emulsion, polyacrylate emulsion, polyacrylonitrile emulsion, polymethacrylate emulsion, and rubber emulsion-based adhesive;
The conductive agent comprises at least one of carbon nano tube, graphite conductive agent, conductive carbon black, ketjen black, acetylene black, graphene and carbon fiber;
the solvent comprises at least one of water, halogenated hydrocarbon solvent with 1-3 carbon atoms, alkane with 5-8 carbon atoms, pyrrolidone with 5-8 carbon atoms, amide with 3-6 carbon atoms, carboxylic acid ester with 3-6 carbon atoms, carbonic acid ester with 3-6 carbon atoms, ketone with 3-6 carbon atoms, alcohol with 1-5 carbon atoms and ether with 4-8 carbon atoms.
8. The method of manufacturing an electrode according to claim 1, wherein the weight ratio of the insoluble fiberizable binder in the conductive fiber is 20 to 60%, the weight ratio of the soluble binder or the dispersed binder is 0 to 20%, 0% is not contained, and the weight ratio of the conductive agent is 20 to 60%.
9. The method of manufacturing an electrode according to claim 1, wherein the step of granulating the conductive fiber with an active material to obtain an electrode powder comprises:
crushing the conductive fibers to form conductive fiber powder, wherein the median particle size of the conductive fiber powder is 5-1000 meshes;
And mixing and granulating the conductive fiber powder and the active substance in an environment of 5-120 ℃ to obtain the electrode powder.
10. The method of manufacturing an electrode according to claim 1, wherein the conductive fiber in the electrode has a diameter of 0.5 μm to 50 μm and a length of 30 μm to 500 μm and an aspect ratio of 3 to 300:1.
11. The method for preparing an electrode according to claim 1, wherein the active material is 80 to 99% by weight of the electrode powder, and the conductive fiber is 1 to 20% by weight of the electrode powder;
the active material comprises 0-20% of solid electrolyte by weight of the electrode powder, wherein the solid electrolyte is sulfide.
12. The method according to claim 1, wherein in the step of forming the electrode film by extruding the electrode powder into a film, the thickness of the electrode film is 80 μm to 180 μm, the MD tensile strength is 0.5MPa or more, the td tensile strength is 0.17MPa or more, and the specific resistance is 20Ω·cm or less.
13. The electrode preparation method according to claim 1, wherein the electrode powder is extruded into a film by a roll press, the roll press at least comprises two press rolls, the linear speed ratio of the roll surfaces of the two press rolls is 1:1-1:16, and the temperature of the roll surfaces is 50-250 ℃.
14. The method of preparing an electrode according to claim 1, wherein the step of connecting the electrode membrane with a current collector to form an electrode comprises:
a conductive adhesive layer is arranged on at least one of the electrode membrane and the current collector;
and bonding the electrode membrane and the current collector through the conductive adhesive layer to form the electrode.
15. The method of manufacturing an electrode according to claim 14, wherein the conductive adhesive layer is coated on the current collector, and the thickness of the conductive adhesive layer is 0.5 μm to 3 μm;
the electrode membrane, the conductive adhesive layer and the current collector are bonded through hot pressing, the temperature during hot pressing is 50-250 ℃, and the line pressure during hot pressing is 0.5-80 tons of force/meter.
16. An electrode, characterized in that the electrode is manufactured according to the electrode manufacturing method of any one of claims 1 to 15.
17. A battery comprising the electrode of claim 16.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2023107081969 | 2023-06-14 | ||
| CN202310708196 | 2023-06-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116979013A true CN116979013A (en) | 2023-10-31 |
Family
ID=88484262
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310856019.5A Pending CN116979013A (en) | 2023-06-14 | 2023-07-12 | Electrode preparation method, electrode and battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116979013A (en) |
-
2023
- 2023-07-12 CN CN202310856019.5A patent/CN116979013A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113675362A (en) | Method and system for preparing electrode slice by dry method and application | |
| US7567429B2 (en) | Electrode material for electric double layer capacitor and process for producing the same | |
| CN100452487C (en) | Secondary battery and method for producing the same | |
| JP4978467B2 (en) | Electrochemical element electrode material and composite particles | |
| CN102629681B (en) | Powder-based electrode forming method | |
| KR101245055B1 (en) | Composite particles for electrochemical element electrode, process for producing composite particles for electrochemical element electrode, and electrochemical element electrode | |
| JP5640996B2 (en) | Battery electrode manufacturing method and battery electrode | |
| WO2013027686A1 (en) | Composite active material for lithium secondary batteries and method for producing same | |
| CN113964288B (en) | Preparation method of fiber membrane and pole piece | |
| JP2016103479A (en) | Manufacturing method of lithium electrode, and lithium secondary battery including lithium electrode | |
| CN113937284B (en) | Film for battery electrode and preparation method thereof | |
| CN108428868A (en) | A kind of method of nano-graphene modification lithium-ion battery anode slurry | |
| CN112133882A (en) | Solvent-free preparation method of electrode for electrochemical energy storage device | |
| CN116230868A (en) | Pole piece, manufacturing method thereof and battery | |
| CN115911260A (en) | Dry-method electrode pole piece, preparation method thereof and battery containing pole piece | |
| CN116387509A (en) | Composite positive electrode for lithium metal battery and preparation method thereof | |
| CN117199261A (en) | Dry pole piece, preparation method thereof and secondary battery | |
| JP2012113945A (en) | Negative electrode material for lithium ion battery and method for producing the same | |
| CN116979013A (en) | Electrode preparation method, electrode and battery | |
| CN114899364B (en) | Negative electrode plate and preparation method and application thereof | |
| JP6090032B2 (en) | Method for forming electrode layer for secondary battery | |
| CN115881888A (en) | Regulation and control method for dry-method electrode fibrosis | |
| CN115084528A (en) | Preparation method and application of carbon-coated metal foil | |
| CN114005951A (en) | Extrusion coating equipment for coating carbon material outside manganese dioxide and application of extrusion coating equipment | |
| CN113119337A (en) | Method for filling and granulating for extrusion molding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |