CN110828772A - Dry preparation process of pole piece and continuous production equipment of pole piece - Google Patents
Dry preparation process of pole piece and continuous production equipment of pole piece Download PDFInfo
- Publication number
- CN110828772A CN110828772A CN201911240475.7A CN201911240475A CN110828772A CN 110828772 A CN110828772 A CN 110828772A CN 201911240475 A CN201911240475 A CN 201911240475A CN 110828772 A CN110828772 A CN 110828772A
- Authority
- CN
- China
- Prior art keywords
- pole piece
- dry powder
- heating
- assembly
- dry
- 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.)
- Granted
Links
- 238000002360 preparation method Methods 0.000 title claims abstract description 23
- 238000010924 continuous production Methods 0.000 title claims abstract description 12
- 239000000843 powder Substances 0.000 claims abstract description 174
- 238000010438 heat treatment Methods 0.000 claims abstract description 138
- 229920002725 thermoplastic elastomer Polymers 0.000 claims abstract description 30
- 238000005096 rolling process Methods 0.000 claims abstract description 26
- 239000002904 solvent Substances 0.000 claims abstract description 20
- 239000006258 conductive agent Substances 0.000 claims abstract description 17
- 238000007790 scraping Methods 0.000 claims abstract description 17
- 239000013543 active substance Substances 0.000 claims abstract description 14
- 238000002156 mixing Methods 0.000 claims abstract description 12
- 238000001035 drying Methods 0.000 claims abstract description 11
- 239000011259 mixed solution Substances 0.000 claims abstract description 6
- 238000000034 method Methods 0.000 claims description 19
- 238000009826 distribution Methods 0.000 claims description 12
- 239000004744 fabric Substances 0.000 claims description 11
- 230000008569 process Effects 0.000 claims description 10
- 238000005098 hot rolling Methods 0.000 claims description 8
- 229920006132 styrene block copolymer Polymers 0.000 claims description 7
- 238000011282 treatment Methods 0.000 claims description 6
- -1 polybutylene terephthalate Polymers 0.000 claims description 5
- 229920001707 polybutylene terephthalate Polymers 0.000 claims description 4
- 229920000058 polyacrylate Polymers 0.000 claims description 3
- 229920000098 polyolefin Polymers 0.000 claims description 3
- 238000011084 recovery Methods 0.000 claims description 3
- 239000007787 solid Substances 0.000 claims description 3
- 239000011888 foil Substances 0.000 description 44
- 229910052782 aluminium Inorganic materials 0.000 description 43
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 43
- 238000000576 coating method Methods 0.000 description 35
- 239000000463 material Substances 0.000 description 29
- 239000011248 coating agent Substances 0.000 description 26
- 239000011149 active material Substances 0.000 description 21
- 239000000428 dust Substances 0.000 description 17
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 14
- 239000011889 copper foil Substances 0.000 description 14
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 13
- 229910001416 lithium ion Inorganic materials 0.000 description 13
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 10
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 description 10
- 238000012360 testing method Methods 0.000 description 10
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 9
- 239000000243 solution Substances 0.000 description 9
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- 238000010030 laminating Methods 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 7
- 238000004806 packaging method and process Methods 0.000 description 7
- 238000004080 punching Methods 0.000 description 7
- 238000004064 recycling Methods 0.000 description 7
- 230000001105 regulatory effect Effects 0.000 description 7
- 238000003756 stirring Methods 0.000 description 7
- 238000003860 storage Methods 0.000 description 7
- 238000003466 welding Methods 0.000 description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 6
- 239000000853 adhesive Substances 0.000 description 6
- 230000001070 adhesive effect Effects 0.000 description 6
- 238000007765 extrusion coating Methods 0.000 description 6
- 229910052744 lithium Inorganic materials 0.000 description 6
- 239000002002 slurry Substances 0.000 description 6
- 238000007581 slurry coating method Methods 0.000 description 6
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 5
- 239000006230 acetylene black Substances 0.000 description 5
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 5
- 238000003825 pressing Methods 0.000 description 5
- 239000002134 carbon nanofiber Substances 0.000 description 4
- 229920001577 copolymer Polymers 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 239000011261 inert gas Substances 0.000 description 4
- 238000003892 spreading Methods 0.000 description 4
- 230000007480 spreading Effects 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 239000005030 aluminium foil Substances 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 3
- DMEGYFMYUHOHGS-UHFFFAOYSA-N heptamethylene Natural products C1CCCCCC1 DMEGYFMYUHOHGS-UHFFFAOYSA-N 0.000 description 3
- 238000012216 screening Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- RGSFGYAAUTVSQA-UHFFFAOYSA-N Cyclopentane Chemical compound C1CCCC1 RGSFGYAAUTVSQA-UHFFFAOYSA-N 0.000 description 2
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 2
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 2
- 239000005062 Polybutadiene Substances 0.000 description 2
- 229920002367 Polyisobutene Polymers 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 239000006255 coating slurry Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- WJTCGQSWYFHTAC-UHFFFAOYSA-N cyclooctane Chemical compound C1CCCCCCC1 WJTCGQSWYFHTAC-UHFFFAOYSA-N 0.000 description 2
- 239000004914 cyclooctane Substances 0.000 description 2
- 238000005034 decoration Methods 0.000 description 2
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004093 laser heating Methods 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
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000005543 nano-size silicon particle Substances 0.000 description 2
- 229920001084 poly(chloroprene) Polymers 0.000 description 2
- 229920002857 polybutadiene Polymers 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 238000009423 ventilation Methods 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- 239000002033 PVDF binder Substances 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
- SOXUFMZTHZXOGC-UHFFFAOYSA-N [Li].[Mn].[Co].[Ni] Chemical compound [Li].[Mn].[Co].[Ni] SOXUFMZTHZXOGC-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 238000010923 batch production Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- XRERONKQLIQWGW-UHFFFAOYSA-N but-1-ene;styrene Chemical compound CCC=C.C=CC1=CC=CC=C1 XRERONKQLIQWGW-UHFFFAOYSA-N 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001924 cycloalkanes Chemical class 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000007580 dry-mixing Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000013467 fragmentation Methods 0.000 description 1
- 238000006062 fragmentation reaction Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 239000002808 molecular sieve Substances 0.000 description 1
- TVMXDCGIABBOFY-UHFFFAOYSA-N octane Chemical compound CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920001485 poly(butyl acrylate) polymer Polymers 0.000 description 1
- 229920001483 poly(ethyl methacrylate) polymer Polymers 0.000 description 1
- 229920000120 polyethyl acrylate Polymers 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Images
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
- H01M4/0402—Methods of deposition of the material
- H01M4/0404—Methods of deposition of the material by coating on electrode collectors
-
- 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
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
-
- 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
- H01M4/621—Binders
- H01M4/622—Binders being polymers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a dry preparation process of a pole piece, which comprises the following steps: s1: mixing an active substance, a conductive agent, a thermoplastic elastomer and a solvent, dissolving the thermoplastic elastomer in the solvent, and drying the mixed solution to obtain dry powder wrapped and mixed by the thermoplastic elastomer; s2: uniformly distributing the dry powder obtained in the step S1 on the surface of the current collector, scraping the surface of the dry powder and adjusting the thickness of the dry powder layer; s3: heating the pole piece with the dry powder layer; s4: rolling the pole piece with the single-sided dry powder layer by using a hot roller to obtain a single-sided pole piece finished product; or repeating the steps S2 and S3 on the other side of the current collector in the pole piece obtained in the step S3, and rolling the pole piece with the double-sided dry powder layer by using a hot roller to obtain a double-sided pole piece finished product. The dry preparation process of the pole piece has reasonable steps, the active substances, the conductive agent and the thermoplastic elastomer in the obtained pole piece are uniformly distributed, and the pole piece has good flexibility. The invention also discloses continuous production equipment of the pole piece.
Description
Technical Field
The invention relates to the technical field of lithium battery material production, in particular to a dry preparation process of a pole piece and continuous production equipment of the pole piece.
Background
The production process of the pole piece of the lithium ion battery is closely related to the quality of the battery, is an important step for controlling the yield of the battery, and is also one of the key points of cost control.
The common pole piece manufacturing process comprises three steps of slurry mixing, coating and drying and rolling: in the slurry mixing process, water or NMP accounting for more than 50 wt% of the whole mass is generally used as a solvent, active substances, a binder and a conductive agent are added, and a slurry with a certain viscosity is prepared in a stirring or screw extrusion mode; in the coating process, the slurry obtained by mixing the slurry is coated on a current collector in a certain thickness in a transfer coating or extrusion coating mode; in the step of drying and rolling, the current collector with the surface coating slurry layer is dried by a drying tunnel to obtain a finished pole piece, or further rolled to obtain the finished pole piece. The production process of the double-sided pole piece is as described in CN 105336920B, and comprises front coating of the current collector, primary drying, back coating of the current collector, and secondary drying in sequence.
The technical defects of the pole piece prepared by coating slurry are as follows: firstly, a current collector continuously supplies materials, the drying tunnel is long in length, large in occupied area, high in energy loss and large in VOC discharge amount; secondly, the materials coated with the redundant parts are treated as waste materials and cannot be recycled; thirdly, the active substance coated by the slurry is easily layered with the conductive agent and the binder, so that the components are unevenly distributed in the dried pole piece adhesive material, and the flexibility of the pole piece is influenced.
The improved technical scheme is as described in CN105070879A, and comprises the steps of dry mixing of powder, spray coating of dry mixed powder, hot rolling and the like. The technical defects of the scheme are as follows: firstly, the roller sticking probability of powder is high during rolling; secondly, when the method is used for producing the double-sided pole piece, two hot rolling treatments need to be correspondingly arranged, otherwise, the problems of powder falling and the like easily occur when the reverse side of the current collector is sprayed and coated, and the yield of the pole piece is not ensured; the third, preferred adhesive is one or a combination of more than two of CMC, PVDF and HFP, and the adhesive does not have the instant effect of heating bonding, resulting in low adhesion between the current collector and the dry powder, and aggravating the phenomena of powder falling and roller sticking.
Disclosure of Invention
One of the purposes of the invention is to overcome the defects in the prior art and provide a dry preparation process of a pole piece, wherein the defects of powder falling, roller sticking and the like in the production process are overcome by adopting a method of firstly heating and then rolling dry powder wrapped and mixed by a thermoplastic elastomer.
In order to achieve the technical effects, the technical scheme of the invention is as follows: a dry preparation process of a pole piece is characterized by comprising the following steps:
s1: mixing an active substance, a conductive agent, a thermoplastic elastomer and a solvent, dissolving the thermoplastic elastomer in the solvent, and drying the mixed solution to obtain dry powder wrapped and mixed by the thermoplastic elastomer;
s2: uniformly distributing the dry powder obtained in the step S1 on the surface of the current collector, scraping the surface of the dry powder and adjusting the thickness of the dry powder layer;
s3: heating the pole piece with the dry powder layer;
s4: rolling the pole piece with the single-sided dry powder layer by using a hot roller to obtain a single-sided pole piece finished product; or repeating the steps S2 and S3 on the other side of the current collector in the pole piece obtained in the step S3, and rolling the pole piece with the double-sided dry powder layer by using a hot roller to obtain a double-sided pole piece finished product.
The preferable technical scheme is that the current collector is continuously fed, the heating in S3 is limiting heating of the pole piece, the width of a heating area of the limiting heating is smaller than that of the dry powder layer, and the limiting heating is non-contact heating; and the heating treatment also comprises a recovery treatment step of the dry powder outside the heating area.
Preferably, the thermoplastic elastomer is one or a combination of two or more selected from the group consisting of polyolefin, polyacrylate, polybutylene-styrene block copolymer, polyisobutylene-styrene block copolymer, and polybutylene terephthalate.
The preferable technical scheme is that the thermoplastic elastomer accounts for 1.5-10% of the dry powder by weight; the active substance accounts for 70-95% of the dry powder by weight; the conductive agent accounts for 2-20% of the dry powder by weight; the solid content of the mixed solution is 5-50 wt%.
Further, the weight percentage of the thermoplastic elastomer in the dry powder is preferably 2-7%, and more preferably 2.5-5%.
Further, the solid content of the mixed solution is 15 to 45 wt%, more preferably 20 to 40 wt%, and most preferably 25 to 35 wt%.
The preferable technical scheme is that the heating temperature in the S3 is 80-200 ℃. Preferably, the heating temperature in S3 is 100-180 ℃, more preferably 120-160 ℃.
The preferable technical scheme is that the technological parameters of the hot roller rolling are as follows: the temperature of the hot roller is 70-150 ℃, and the rolling pressure is 10-300 tons. Preferably, the temperature is 90-130 ℃, the rolling pressure is 50-200 tons, more preferably, the temperature is 100-120 ℃, and the rolling pressure is 80-150 tons.
The preferable technical proposal is that the feeding speed of the current collector for continuous feeding is 0.2 m/min-10 m/s.
The invention also aims to provide continuous production equipment of pole pieces, which comprises a current collector unreeling assembly and a pole piece reeling assembly, and is characterized by further comprising a first powder distributing unit, a first heating assembly and a hot rolling assembly which are sequentially arranged between the current collector unreeling assembly and the pole piece reeling assembly, wherein the first powder distributing unit comprises a first screen assembly and a first slit strickling assembly which are arranged above a current collector feeding path.
The preferable technical scheme is that the feeding path of the current collector is U-shaped, the feeding path of the current collector comprises two parallel and horizontal path sections, and the first powder distribution unit is positioned above the path sections; the second powder distribution unit is arranged above the other horizontal path section and comprises a second screen assembly and a second slit slicking assembly which are sequentially arranged.
The preferable technical scheme is that the first heating assembly is a non-contact heating assembly, and a powder sucking assembly for sucking dry powder outside the heating area is arranged on the discharge side of the first heating assembly.
The invention has the advantages and beneficial effects that:
according to the dry preparation process of the pole piece, firstly, the dissolved thermoplastic elastomer is adopted to prepare the package mixed dry powder, so that the thermoplastic elastomer is uniformly distributed on the surfaces of the active material and the conductive agent, and the solvent is intensively recovered and can be repeatedly utilized in the preparation process of the dry powder;
because the thermoplastic elastomer has the characteristic of being heated and bonded, the thermoplastic elastomers which are wrapped and mixed between the active substance and the conductive agent particles are bonded with each other after being heated, and meanwhile, the thermoplastic elastomers are fully bonded with the current collector, so that the phenomenon that dry powder on the first surface falls off when the second surface of the subsequent current collector is coated is avoided, and/or the phenomenon that the powder is bonded with a roller when the subsequent pole piece is rolled in a hot manner is avoided, and the yield of the pole piece is improved;
the components in the thermoplastic elastomer preparation package mixing dry powder are uniformly distributed, so that the problem of layering of active substances, conductive agents and adhesives is avoided, the thermoplastic elastomer has good elasticity and small tensile strength, the pole piece prepared by the dry process has good flexibility, and the adhesive force between powder and a current collector after rolling treatment is good;
compared with common slurry coating, the dry powder distribution speed is high, no solvent is volatilized in the heating step, and the occupied area of the used heating component is small; the current collector and the dry powder layer on the surface of the current collector are heated rapidly, and the production efficiency of the pole piece is high.
Drawings
FIG. 1 is a schematic view showing the structure of a continuous production apparatus for pole pieces in example 1;
fig. 2 is a schematic structural diagram of a current collector, a dry powder layer and a limiting heating area;
FIG. 3 is an SEM photograph of a foil obtained by the process of the present invention;
FIG. 4 is a schematic view showing the structure of a continuous production apparatus for pole pieces in example 8;
in the figure: 1. the current collector unreeling assembly; 2. a first powder distribution unit; 21. a first screen assembly; 22. a first slit strickle component; 3. a first heating assembly; 4. a second powder distribution unit; 41. a second screen assembly; 42. a second slit strickle component; 5. a second heating assembly; 6. a hot rolling assembly; 7. a pole piece winding assembly; 8. a powder suction assembly;
a. a current collector; b. a dry powder layer; c. the heating area is limited.
Detailed Description
The following further describes embodiments of the present invention with reference to examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
Thermoplastic elastomer
Specifically, the thermoplastic elastomer serves to bond the conductive agent, the active material and the current collector, and is selected from the group consisting of polyolefins (e.g., polyisobutylene, polybutadiene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, etc.), polyacrylates (e.g., polyethylacrylate, polyethylmethacrylate, polyacrylic acid-butyl methacrylate, etc.), polybutylene-styrene block copolymer, polyisobutylene-styrene block copolymer, chloroprene rubber, and polybutylene terephthalate.
Active substance
The pole pieces are divided into a positive pole piece and a negative pole piece, so that active substances in the pole pieces are also distinguished by the positive pole and the negative pole. The active material of the positive pole piece comprises but is not limited to one or the combination of more than two of lithium cobaltate, lithium manganate, lithium nickel cobalt manganese and lithium iron phosphate, and the active material of the positive pole piece comprises but is not limited to artificial graphite, silicon material, silicon carbon material and silicon protoxide material.
Conductive agent
The conductive agent may be any known one, and includes, but is not limited to, one or a combination of two or more of acetylene black, carbon fiber, and ketjen black.
Solvent(s)
The solvent is defined as being soluble in the thermoplastic elastomer, and thus the solvent may be specifically selected depending on the thermoplastic elastomer. Specifically, the solvent is one or a combination of two or more selected from alkanes (pentane, hexane, heptane, octane), cycloalkanes (cyclopentane, cyclohexane, cycloheptane, cyclooctane), benzene homologues (benzene, toluene, xylene), ketones (acetone, methyl ethyl ketone, etc.), and esters (methyl acetate, ethyl acetate, etc.) which are liquid at room temperature. More preferably, the solvent is one or a combination of two or more of cyclohexane, cyclooctane, methyl acetate and ethyl acetate.
Mixing mode of conductive agent, active substance, solvent and thermoplastic elastomer in S1
The order of mixing and feeding the conductive agent, the active material, the solvent and the thermoplastic elastomer is not limited. Preferably, the conductive agent and the active substance are added into the container, and the thermoplastic elastomer solution is slowly and uniformly sprayed while stirring.
Such vessels include, but are not limited to, laboratory equipment (stirred tanks or beakers) and batch production equipment (double cone mixers, high speed dry powder mixers or coulter blenders).
Laying out dry powder and controlling dry powder layer thickness in S2
The dry powder may be distributed in a uniform and homogeneous powder distribution, including but not limited to conventional screen cloth. The cloth sieving process involves feeding dry powder into the sieve body, wherein the feeding can be manual operation, or powder feeding equipment such as a screw continuous feeding device, an intermittent discharging device and the like is adopted.
Furthermore, the dry powder screening device is a square or approximately square screen provided with high-frequency vibration, the aperture of the dry powder screening device is adjustable between 50 meshes and 250 meshes, and the vibration frequency of the dry powder screening device is adjustable between 50Hz and 50000 Hz. Preferably, the aperture is between 100 and 200 meshes, the vibration frequency is between 1000 and 40000Hz, more preferably, the aperture is about 150 meshes, and the vibration frequency is between 10000 and 50000 Hz.
And the thickness of the dry powder layer is controlled by adopting a slit leveling component, the width of the slit is determined according to the type of the current collector and the amount of substances on the surface of the current collector, and the width of the slit is adjusted within the range of 10-1000 mu m. A common slit strickle component includes a current collector stage and a scraper blade that can be lifted above the UI current collector stage. The size of the interval between the carrier and the scraper is the width of the slit.
Current collector
Common current collectors: the positive current collector is aluminum foil and the negative current collector is copper foil.
Heating of S3
The heating method in S3 is preferably non-contact heating, and depending on the heat source, the preferred heating method is one or a combination of two or more selected from the group consisting of electromagnetic heating, intermediate frequency heating, laser heating, and infrared heating.
Further, the heating is limited heating. The limit heating means that the width of the heating area is constant, and the width of the heating area and the width of the dry powder are consistent with the width direction of a current collector (continuously fed aluminum foil or copper foil). Furthermore, the width of the dry powder layer obtained in the step S2 is smaller than that of the current collector, namely, aluminum foil allowance is arranged on two sides of the scraped dry powder layer, the allowance of non-bonded dry powder is arranged on two sides of the limited heating area, and the dry powder can be recycled and reused in the step S1, so that the material utilization rate and the heat utilization rate are improved.
The recovery device of the dry powder is a known fine powder material removing device, and is generally an electrostatic dust removing device, a negative pressure dust removing device, and preferably a negative pressure dust removing device.
The limit heating mode is electromagnetic limit heating, intermediate frequency limit heating, laser heating and infrared heating.
Unless defined otherwise, technical terms used in the following examples have the same meanings as commonly understood by one of ordinary skill in the art to which the present invention belongs.
The method for testing the adhesive force of the coated pole piece is carried out according to a grid cutting method of GB/T9286-88, and specifically comprises the following steps:
6 mutually parallel 1mm cutting marks with equal spacing are cut on the test piece coating, and then the cutting marks with the same number and spacing are vertically cut.
Chips were gently brushed off in the directions of both diagonal lines with a soft brush, and then evaluated according to the following criteria.
The testing method of the flexibility of the pole piece is to select 5 pole pieces of 10cm x 2cm, fold the long edge 180 degrees, flatten the pole piece, recover to the original state, and observe whether the crease is cracked. If more than 2 fragmentation conditions occur, the pole piece is judged to be brittle fracture.
Example 1
As shown in fig. 1, the continuous production equipment for the pole piece in embodiment 1 includes a current collector unreeling assembly 1 and a pole piece reeling assembly 7, and further includes a first powder distribution unit 2, a first heating assembly 3 and a hot rolling assembly 6 which are sequentially disposed between the current collector unreeling assembly 1 and the pole piece reeling assembly 7, wherein the first powder distribution unit 2 includes a first screen assembly 21 and a first slit leveling assembly 22 which are disposed above a current collector feeding path.
The first heating assembly 3 is a non-contact heating assembly, and a powder sucking assembly 8 for sucking dry powder outside a heating area is arranged on the discharge side of the first heating assembly 3.
The feeding path of the current collector is U-shaped, the feeding path of the current collector comprises two parallel and horizontal path sections, a conveying roller for guiding the current collector is arranged between the two path sections, and the first powder distribution unit 1 is positioned above one path section; the powder spreading device further comprises a second powder spreading unit 4 and a second heating assembly 5 which are sequentially arranged between the first heating assembly 3 and the hot rolling assembly 6, the second powder spreading unit 4 is positioned above the other horizontal path section, and the second powder spreading unit 4 comprises a second screen assembly 41 and a second slit leveling assembly 42 which are sequentially arranged.
The dry preparation process of the pole piece comprises the following steps:
s1: 1400g of lithium cobaltate (70 wt%) and 400g of acetylene black (20 wt%) are used as main materials, the main materials are firstly put into a 10L double-cone mixer, 400g of a cyclohexane solution of polyisobutylene with the content of 50 wt% is added at one time, the double-cone mixer is started to mix for 30min after sealing, and then the cyclohexane is removed for 2 hours by vacuumizing. The removed cyclohexane can be collected by a cold trap and put into use after being dewatered by a molecular sieve;
s2: an aluminum foil with a thickness of 20 μm and a width of 400mm was used as a current collector, and the running speed was 0.2 m/s. Adding the dry powder obtained in the step 1 into a first screen assembly 21 in a manual feeding mode, wherein the mesh number of the screen is 50 meshes, the vibration frequency of the screen is 50Hz, scattering the dry powder on a pole piece, and scraping a dry powder layer through a first slit scraping assembly 22 with the full height of 70 mu m to obtain an aluminum foil with the coating thickness of 50 mu m;
s3: heating the aluminum foil passing right above the first heating assembly 3 through the electromagnetic limiting heating module with the length of 400mm and the width of 25mm, setting the heating temperature to be 80 ℃, and obtaining a current collector a, a dry powder layer b and a limiting heating area c in the pole piece as shown in figure 2;
s4: sucking dry powder which is not adhered to the pole pieces away through the first powder sucking component 81 electrostatic dust removal device, recycling the dry powder into the material storage tank, and returning to the step 2 to sieve the cloth again after the subsequent operation;
s5: through two rollers, overturn the aluminum foil, dry powder is manually fed to a second screen assembly 41, under the same screen mesh number and vibration frequency, the dry powder is scattered on the pole piece, the dry powder layer is strickled off by a second slit strickle-off assembly 42 with the full height of 120 mu m to obtain the aluminum foil with the double-sided coating thickness of 50 mu m, the aluminum foil passing through the right upper part of the aluminum foil is heated by a second heating assembly 5 infrared limiting heating module with the length of 500mm and the width of 25mm, and the heating temperature is set to be 100 ℃. The heating positions of the two heating modules are accurately regulated and controlled, and the deviation is not more than +/-0.2 mm. Then, the unfixed dry powder is thoroughly sucked and removed by a negative pressure dust removal device of a second powder suction assembly 82;
s6: the aluminum foil coated with the active material on both sides was rolled by a hot roll of 50 tons pressure and 70 ℃ temperature in a hot roll press unit 6, and finally molded.
After rolling, the thickness of one side of the pole piece is 37 mu m, and the coating density of the single side is 7.1mg/cm2Compacted density 2.7g/cm3. In the coating process, the efficiency of the active material, the adhesion and flexibility of the pole piece were recorded.
And punching, laminating, welding, injecting liquid, packaging, pre-charging, high-temperature forming and grading the obtained positive pole piece according to the proportion of the N/P ratio of 1.1:1 to obtain the 5Ah soft package lithium ion battery, and testing the capacity, the multiplying power and the alternating current internal resistance of the battery.
As a control, the pole pieces were coated in a conventional extrusion coating manner and assembled into a 5Ah soft pack lithium ion battery, which was tested for capacity, rate and ac impedance as comparative example 1.
The results obtained are shown in the following table:
as can be seen from the above table, the active material utilization efficiency of the pole piece obtained in this embodiment is significantly higher than that of the slurry coating method, and the pole piece has good adhesion and flexibility and small internal resistance.
Example 2
The dry preparation process of the pole piece in the embodiment 2 is as follows:
s1: 2400g of lithium manganate (80 wt%) and 300g of VGCF (10 wt%) are used as main materials, the main materials are firstly put into a 10L beaker, 750g of a 40 wt% polybutadiene toluene solution is slowly dripped while powder is stirred, the dripping is completed within about 10min, and the mixed materials are heated to 80 ℃ under ventilation conditions to enable toluene to be naturally volatilized;
s2: an aluminum foil with a thickness of 20 μm and a width of 400mm was used as a current collector, and the running speed was 1 m/s. Adding the dry powder obtained in the step 1 into a first screen assembly 21 in a manual feeding mode, wherein the mesh number of the screen is 100 meshes, the vibration frequency of the screen is 800Hz, scattering the dry powder on a pole piece, and scraping a dry powder layer through a first slit scraping assembly 22 with the full height of 90 mu m to obtain an aluminum foil with the coating thickness of 70 mu m;
s3: heating the aluminum foil passing through the right upper part of the first heating component 3 by using a medium-frequency induction limiting heating module which is 400mm long and 25mm wide, and setting the heating temperature to be 100 ℃;
s4: sucking dry powder which is not adhered on the pole pieces away by an electrostatic dust removal device of a powder sucking component 8, recycling the dry powder into a material storage tank, and returning to the step 2 to sieve the cloth again after the subsequent process;
s5: through two rollers, overturn the aluminum foil, dry powder is manually fed to a second screen assembly 41, under the same screen mesh number and vibration frequency, the dry powder is scattered on the pole piece, the dry powder layer is strickled off by a second slit strickle-off assembly 42 with the full height of 160 mu m to obtain the aluminum foil with the double-sided coating thickness of 70 mu m, the aluminum foil passing through the right upper part of the aluminum foil is heated by a second heating assembly 5 infrared laser limit heating module with the length of 500mm and the width of 25mm, and the heating temperature is set to be 120 ℃. The heating positions of the two heating modules are accurately regulated and controlled, and the deviation is not more than +/-0.2 mm. Then, the unfixed dry powder is thoroughly sucked and removed by a negative pressure dust removal device of a second powder suction assembly 82;
s6: the aluminum foil coated with the active material on both sides was rolled by a hot roll of 80 tons pressure and 120 ℃ temperature in a hot roll pressing unit 6, and finally molded.
After rolling, the thickness of one side of the pole piece is 52 mu m, and the coating density of the single side is 9.1mg/cm2. In the coating process, the efficiency of the active material, the adhesion and flexibility of the pole piece were recorded.
And punching, laminating, welding, injecting liquid, packaging, pre-charging, high-temperature forming and grading the obtained positive pole piece according to the proportion of the N/P ratio of 1.1:1 to obtain the 5Ah soft package lithium ion battery, and testing the capacity, the multiplying power and the alternating current internal resistance of the battery.
As a control, the pole pieces were coated in a conventional extrusion coating manner and assembled into a 5Ah soft pack lithium ion battery, which was tested for capacity, rate and ac impedance as control example 2.
The results obtained are shown in the following table:
as can be seen from the above table, the active material utilization efficiency of the pole piece obtained in this embodiment is significantly higher than that of the slurry coating method, the adhesion and flexibility of the pole piece are good, and the internal resistance is significantly lower than that of the conventional coating process.
Example 3
The dry preparation process of the pole piece in the embodiment 3 is as follows:
s1: 4500g of lithium iron phosphate (90 wt%), 150g of acetylene black (3 wt%) and 100g of VGCF (2 wt%) are used as main materials, the main materials are put into a 15L high-speed mixer, 833g of an ethylene-propylene copolymer normal hexane solution with the content of 30 wt% is slowly dripped under slow stirring, dripping is completed within 5min, the high-speed mixer is sealed, high-speed mixing is carried out for about 10min, and the mixed materials are heated to 80 ℃ under the ventilation and slow stirring conditions, so that the normal hexane is naturally volatilized.
S2: an aluminum foil with a thickness of 20 μm and a width of 400mm was used as a current collector, and the running speed was 2 m/s. And (3) adding the dry powder obtained in the step (1) into a first screen assembly 21 in a screw automatic feeding mode, wherein the mesh number of the screen is 150 meshes, the vibration frequency of the screen is 1500Hz, scattering the dry powder on the pole piece, and scraping the dry powder layer through a first slit scraping assembly 22 with the full height of 100 mu m to obtain the aluminum foil with the coating thickness of 80 mu m.
S3: the aluminum foil passing through the right upper part of the first heating component 3 is heated by the infrared limiting heating module with the length of 500mm and the width of 25mm, and the heating temperature is set to be 110 ℃.
S4: sucking dry powder which is not adhered on the pole pieces away by an electrostatic dust removal device of a powder sucking component 8, recycling the dry powder into a material storage tank, and returning to the step 2 to sieve the cloth again after the subsequent process;
s5: through two change rollers, overturn the aluminium foil, and the dry powder is in the reinforced second screen assembly 41 of screw rod autoloading, under equal screen mesh number and vibration frequency, sprinkle the dry powder on the piece, and strickle the dry powder layer off through the second slit strickle-off subassembly 42 that the full height is 180 mu m, obtain the aluminium foil of two-sided coating thickness 80 mu m, and through the 5 infrared spacing heating module of second heating assembly 5 of 500mm wide 25mm of length, heat the aluminium foil that passes through directly over it, and set for heating temperature 130 ℃. The heating positions of the two heating modules are accurately regulated and controlled, and the deviation is not more than +/-0.2 mm. Then, the unfixed dry powder is thoroughly sucked and removed by a negative pressure dust removal device of a second powder suction assembly 82;
s6: the aluminum foil coated with the active material on both sides was rolled by a hot roll of 110 tons pressure and 130 ℃ temperature in the hot roll pressing unit 6, and finally formed.
After rolling, the thickness of one side of the pole piece is 64 mu m, and the coating density of the single side is 10mg/cm2. In the coating process, the efficiency of the active material, the adhesion and flexibility of the pole piece were recorded.
And punching, laminating, welding, injecting liquid, packaging, pre-charging, high-temperature forming and grading the obtained positive pole piece according to the proportion of the N/P ratio of 1.1:1 to obtain the 5Ah soft package lithium ion battery, and testing the capacity, the multiplying power and the alternating current internal resistance of the battery.
As a control, the electrode sheets were coated in a conventional extrusion coating manner and assembled into a 5Ah soft pack lithium ion battery, which was tested for capacity, rate and ac impedance as control example 3.
The results obtained are shown in the following table:
as can be seen from the above table, the pole piece obtained by the method is significantly superior to the slurry coating method.
Example 4
The dry preparation process of the pole piece in the embodiment 4 is as follows:
s1: firstly putting 4650g of nano lithium titanate (93 wt%), 125g of acetylene black (2.5 wt%) and 125g of CNT (0.1 wt%) with the concentration of 4 wt% as main materials into a 15L high-speed mixer, slowly dropwise adding 1100g of methyl acetate solution of chloroprene rubber with the content of 50 wt% under slow stirring, finishing adding within 15min, sealing the mixer, stirring at high speed for about 20min, and then volatilizing the methyl acetate and a solvent in the CNT under the condition of negative pressure;
s2: the copper foil with the thickness of 10 μm and the width of 400mm was used as a current collector, and the traveling speed was 5 m/s. Adding the dry powder obtained in the step 1 into a first screen assembly 21 in a manual feeding mode, wherein the mesh number of the screen is 200 meshes, the vibration frequency of the screen is 5000Hz, scattering the dry powder on a pole piece, and scraping a dry powder layer through a first slit scraping assembly 22 with the full height of 80 mu m to obtain an aluminum foil with the coating thickness of 70 mu m;
s3: heating the copper foil passing through the right upper part of the first heating component 3 by using an infrared limiting heating module of the first heating component 3 with the length of 500mm and the width of 25mm, and setting the heating temperature to be 130 ℃;
s4: sucking dry powder which is not adhered on the pole pieces away by an electrostatic dust removal device of a powder sucking component 8, recycling the dry powder into a material storage tank, and returning to the step 2 to sieve the cloth again after the subsequent process;
s5: through two rollers, overturn the aluminum foil, dry powder is manually fed to a second screen assembly 41, under the same screen mesh number and vibration frequency, the dry powder is scattered on the pole piece, the dry powder layer is strickled off by a second slit strickle-off assembly 42 with the full height of 150 mu m to obtain the aluminum foil with the double-sided coating thickness of 70 mu m, the copper foil passing through the position right above the aluminum foil is heated by a second heating assembly 5 infrared limiting heating module with the length of 500mm and the width of 25mm, and the heating temperature is set to be 130 ℃. The heating positions of the two heating modules are accurately regulated and controlled, and the deviation is not more than +/-0.2 mm. Then, the unfixed dry powder is thoroughly sucked and removed by a negative pressure dust removal device of a second powder suction assembly 82;
s6: the aluminum foil coated with the active material on both sides was rolled by a hot roll of 150 tons pressure and 140 ℃ temperature in the hot roll pressing unit 6, and finally formed.
After rolling, the thickness of one side of the pole piece is 61 μm, and the coating density of the single side is 8mg/cm2. In the coating process, the efficiency of the active material, the adhesion and flexibility of the pole piece were recorded.
And punching, laminating, welding, injecting liquid, packaging, pre-charging, high-temperature forming and grading the obtained positive pole piece according to the proportion of the N/P ratio of 1.1:1 to obtain the 5Ah soft package lithium ion battery, and testing the capacity, the multiplying power and the alternating current internal resistance of the battery.
As a control, the pole pieces were coated in a conventional extrusion coating manner and assembled into a 5Ah soft pack lithium ion battery, which was tested for capacity, rate and ac impedance as control example 4.
The results obtained are shown in the following table:
as can be seen from the above table, the pole piece obtained by the method is superior to the slurry coating method.
Example 5
The dry preparation process of the pole piece in example 5 is as follows:
s1: firstly, 4850g of graphite cathode (97 wt%) is taken as a main material, the main material is put into a 15L high-speed mixer, 1500g of cyclohexane solution of butene-styrene block copolymer with the content of 10 wt% is slowly dripped under slow stirring, the addition is completed within about 30min, after the closed mixer is stirred at high speed for about 30min, under the condition of negative pressure, cyclohexane solvent is volatilized, and volatilized cyclohexane is collected through a cold trap;
s2: copper foil with a thickness of 10 μm and a width of 400mm was used as a current collector, and the traveling speed was 7 m/s. Adding the dry powder obtained in the step 1 into a first screen assembly 21 in a screw automatic feeding mode, wherein the mesh number of the screen is 50 meshes, the vibration frequency of the screen is 30000Hz, scattering the dry powder on a pole piece, and scraping a dry powder layer through a first slit scraping assembly 22 with the full height of 150 mu m to obtain an aluminum foil with the coating thickness of 140 mu m;
s3: heating the copper foil passing through the right upper part of the first heating component 3 by using an infrared limiting heating module of the first heating component 3, wherein the length of the first heating component is 250mm, the width of the first heating component is 25mm, and the heating temperature is set to be 150 ℃;
s4: sucking dry powder which is not adhered on the pole pieces away by an electrostatic dust removal device of a powder sucking component 8, recycling the dry powder into a material storage tank, and returning to the step 2 to sieve the cloth again after the subsequent process;
s5: through two rollers, the aluminum foil is overturned, dry powder is automatically fed into a second screen assembly 41 through a screw, under the same screen mesh number and vibration frequency, the dry powder is scattered on the pole piece, the dry powder layer is strickled off through a second slit strickle-off assembly 42 with the full height of 280 mu m to obtain the aluminum foil with the double-sided coating thickness of 140 mu m, the copper foil passing through the position right above the aluminum foil is heated through a second heating assembly 5 infrared limiting heating module with the length of 250mm and the width of 25mm, and the heating temperature is set to be 160 ℃. The heating positions of the two heating modules are accurately regulated and controlled, and the deviation is not more than +/-0.2 mm. Then, the unfixed dry powder is thoroughly sucked and removed by a negative pressure dust removal device of a second powder suction assembly 82;
s6: the aluminum foil coated with the active material on both sides was rolled by a hot roll of 150 tons pressure and 170 ℃ in a hot roll press unit 6, and finally formed.
After rolling, the thickness of one side of the pole piece is 97 μm, and the coating density of the single side is 9mg/cm2. In the coating process, the efficiency of the active material, the adhesion and flexibility of the pole piece were recorded.
And punching, laminating, welding, injecting liquid, packaging, pre-charging, high-temperature forming and grading the obtained positive pole piece according to the proportion of the N/P ratio of 1.1:1 to obtain the 5Ah soft package lithium ion battery, and testing the capacity, the multiplying power and the alternating current internal resistance of the battery.
As a control, the electrode sheets were coated in a conventional extrusion coating manner and assembled into a 5Ah soft pack lithium ion battery, as a control example 5, the capacity, rate and ac impedance of the battery were tested.
The results obtained are shown in the following table:
as can be seen from the above table, the pole piece obtained by the method is significantly superior to the slurry coating method.
Example 6
The dry preparation process of the pole piece in example 6 is as follows:
s1: 4500g of nano silicon powder (90 wt%), 150g of VGCF (3 wt%) and 50g of lithium metal powder (1%) are used as main materials, the main materials are put into a 15L double-cone mixer under the protection of inert gas, 1000g of methyl acetate (anhydrous) solution of polybutylene terephthalate with the content of 30 wt% is dropwise added, the adding is completed within 30min, the mixer is sealed again, high-speed mixing is carried out for about 30min, a methyl acetate solvent is volatilized under the condition of negative pressure, and the volatilized methyl acetate is collected through a cold trap.
S2: under the protection of inert gas, a copper foil with the thickness of 10 mu m and the width of 400mm is used as a current collector, and the traveling speed is 10 m/s. Adding the dry powder obtained in the step 1 into a first screen assembly 21 in a manual feeding mode, wherein the mesh number of the screen is 150 meshes, the vibration frequency of the screen is 30000Hz, scattering the dry powder on a pole piece, and scraping a dry powder layer through a first slit scraping assembly 22 with the full height of 80 mu m to obtain an aluminum foil with the coating thickness of 70 mu m;
s3: heating the copper foil passing through the right upper part of the first heating component 3 by using an infrared limiting heating module of the first heating component 3, wherein the length of the first heating component is 250mm, the width of the first heating component is 25mm, and the heating temperature is set to be 130 ℃;
s4: sucking dry powder which is not adhered on the pole pieces away by an electrostatic dust removal device of a powder sucking component 8, recycling the dry powder into a material storage tank, and returning to the step 2 to sieve the cloth again after the subsequent process;
s5: through two rollers, the aluminum foil is overturned, dry powder is manually fed to a second screen assembly 41, under the same screen mesh number and vibration frequency, the dry powder is scattered on the pole piece, the dry powder layer is strickled off through a second slit strickle-off assembly 42 with the full height of 150 mu m to obtain the aluminum foil with the double-sided coating thickness of 70 mu m, the copper foil passing through the position right above the aluminum foil is heated through a second heating assembly 5 infrared limiting heating module with the length of 250mm and the width of 25mm, and the heating temperature is set to be 140 ℃. The heating positions of the two heating modules are accurately regulated and controlled, and the deviation is not more than +/-0.2 mm. Then, the unfixed dry powder is thoroughly sucked and removed by a negative pressure dust removal device of a second powder suction assembly 82;
s6: the aluminum foil coated with the active material on both sides was rolled by a hot roll of 95 tons pressure and 130 ℃ temperature in the hot roll pressing unit 6, and finally formed.
After rolling, the thickness of one side of the pole piece is 52 μm, and the coating density of the single side is 7mg/cm 2. In the coating process, the efficiency of the active material, the adhesion and flexibility of the pole piece were recorded.
And punching, laminating, welding, injecting liquid, packaging, pre-charging, high-temperature forming and grading the obtained positive pole piece according to the proportion of the N/P ratio of 1.1:1 to obtain the 5Ah soft package lithium ion battery, and testing the capacity, the multiplying power and the alternating current internal resistance of the battery.
The results obtained are shown in the following table:
example 7
The dry preparation process of the pole piece in example 7 is as follows:
s1: 4250g of nano silicon powder (85 wt%), 100g of acetylene black (2 wt%), 150g of VGCF (3 wt%) and 100g of metal lithium powder (2%) are used as main materials, the main materials are put into a 15L double-cone mixer under the protection of inert gas, 800g of methyl acetate (anhydrous) solution of 50 wt% of polybutyl acrylate is dropwise added within about 30min, the mixer is sealed again, high-speed mixing is carried out for about 30min, under the condition of negative pressure, methyl acetate solvent is volatilized, and the volatilized methyl acetate is collected through a cold trap;
s2: under the protection of inert gas, copper foil with the thickness of 10 μm and the width of 400mm is used as a current collector, and the traveling speed is 7 m/s. Adding the dry powder obtained in the step 1 into a first screen assembly 21 in a manual feeding mode, wherein the mesh number of the screen is 120 meshes, the vibration frequency of the screen is 30000Hz, scattering the dry powder on a pole piece, and scraping a dry powder layer through a first slit scraping assembly 22 with the height of 80 mu m to obtain an aluminum foil with the coating thickness of 70 mu m;
s3: heating the copper foil passing through the right upper part of the first heating component 3 by using an infrared limiting heating module of the first heating component 3, wherein the length of the first heating component is 250mm, the width of the first heating component is 25mm, and the heating temperature is set to be 130 ℃;
s4: sucking dry powder which is not adhered on the pole pieces away by an electrostatic dust removal device of a powder sucking component 8, recycling the dry powder into a material storage tank, and returning to the step 2 to sieve the cloth again after the subsequent process;
s5: through two rollers, the aluminum foil is overturned, dry powder is manually fed to a second screen assembly 41, under the same screen mesh number and vibration frequency, the dry powder is scattered on the pole piece, the dry powder layer is strickled off through a second slit strickle-off assembly 42 with the full height of 150 mu m to obtain the aluminum foil with the double-sided coating thickness of 70 mu m, the copper foil passing through the position right above the aluminum foil is heated through a second heating assembly 5 infrared limiting heating module with the length of 250mm and the width of 25mm, and the heating temperature is set to be 140 ℃. The heating positions of the two heating modules are accurately regulated and controlled, and the deviation is not more than +/-0.2 mm. Then, the unfixed dry powder is thoroughly sucked and removed by a negative pressure dust removal device of a second powder suction assembly 82;
s6: the aluminum foil coated with the active material on both sides was rolled by a hot roll of 95 tons pressure and 130 ℃ temperature in the hot roll pressing unit 6, and finally formed.
After rolling, the thickness of one side of the pole piece is 50 μm, and the coating density of the single side is 6.3mg/cm2. In the coating process, the efficiency of the active material, the adhesion and flexibility of the pole piece were recorded.
And punching, laminating, welding, injecting liquid, packaging, pre-charging, high-temperature forming and grading the obtained positive pole piece according to the proportion of the N/P ratio of 1.15:1 to obtain the 5Ah soft package lithium ion battery, and testing the capacity, the multiplying power and the alternating current internal resistance of the battery.
The results obtained are shown in the following table:
example 8
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A dry preparation process of a pole piece is characterized by comprising the following steps:
s1: mixing an active substance, a conductive agent, a thermoplastic elastomer and a solvent, dissolving the thermoplastic elastomer in the solvent, and drying the mixed solution to obtain dry powder wrapped and mixed by the thermoplastic elastomer;
s2: uniformly distributing the dry powder obtained in the step S1 on the surface of the current collector, scraping the surface of the dry powder and adjusting the thickness of the dry powder layer;
s3: heating the pole piece with the dry powder layer;
s4: rolling the pole piece with the single-sided dry powder layer by using a hot roller to obtain a single-sided pole piece finished product; or repeating the steps S2 and S3 on the other side of the current collector in the pole piece obtained in the step S3, and rolling the pole piece with the double-sided dry powder layer by using a hot roller to obtain a double-sided pole piece finished product.
2. The dry preparation process of the pole piece according to claim 1, wherein the current collector is continuously fed, the heating in S3 is limited heating of the pole piece, and the width of the heating area of the limited heating is smaller than that of the dry powder layer; the limiting heating is non-contact heating; and the heating treatment also comprises a recovery treatment step of the dry powder outside the heating area.
3. The dry process for preparing a pole piece according to claim 1 or 2, wherein the thermoplastic elastomer is one or a combination of two or more selected from the group consisting of polyolefin, polyacrylate, polybutylene-styrene block copolymer, polyisobutylene-styrene block copolymer and polybutylene terephthalate.
4. The dry preparation process of the pole piece according to claim 1, wherein the thermoplastic elastomer accounts for 1.5-10% of the dry powder by weight; the active substance accounts for 70-95% of the dry powder by weight; the conductive agent accounts for 2-20% of the dry powder by weight; the solid content of the mixed solution is 5-50 wt%.
5. The dry preparation process of the pole piece according to claim 1, wherein the heating temperature in the S3 is 80-200 ℃.
6. The dry preparation process of the pole piece according to claim 1, wherein the process parameters of the hot roller rolling are as follows: the temperature of the hot roller is 70-150 ℃, and the rolling pressure is 10-300 tons.
7. The dry preparation process of the pole piece according to claim 2, wherein the feeding speed of the current collector which is continuously fed is 0.2 m/min-10 m/s.
8. The utility model provides a continuous production equipment of pole piece, includes that the mass flow body unreels subassembly and pole piece rolling subassembly, its characterized in that, still including set gradually in the mass flow body unreels first cloth powder unit, first heating element and hot rolling subassembly between subassembly and the pole piece rolling subassembly, first cloth powder unit is including setting up in the first screen assembly and the first slit of mass flow body feeding route top and strickle the subassembly.
9. The continuous production equipment of pole pieces according to claim 8, wherein the feeding path of the current collector is U-shaped, the feeding path of the current collector comprises two parallel and horizontal path sections, and the first powder distribution unit is positioned above the path sections; the second powder distribution unit is arranged above the other horizontal path section and comprises a second screen assembly and a second slit slicking assembly which are sequentially arranged.
10. The continuous production equipment of pole pieces according to claim 8, wherein the first heating assembly is a non-contact heating assembly, and a powder sucking assembly for sucking dry powder outside the heating area is arranged on the discharge side of the first heating assembly.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911240475.7A CN110828772B (en) | 2019-12-06 | 2019-12-06 | Dry preparation process of pole piece and continuous production equipment of pole piece |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911240475.7A CN110828772B (en) | 2019-12-06 | 2019-12-06 | Dry preparation process of pole piece and continuous production equipment of pole piece |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110828772A true CN110828772A (en) | 2020-02-21 |
| CN110828772B CN110828772B (en) | 2020-11-10 |
Family
ID=69544817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911240475.7A Active CN110828772B (en) | 2019-12-06 | 2019-12-06 | Dry preparation process of pole piece and continuous production equipment of pole piece |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110828772B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112652824A (en) * | 2021-01-21 | 2021-04-13 | 天津市捷威动力工业有限公司 | Cylindrical lithium ion battery manufacturing process |
| CN112802987A (en) * | 2020-12-31 | 2021-05-14 | 蜂巢能源科技有限公司 | Method for preparing electrode slice by dry rolling |
| CN113333230A (en) * | 2021-06-03 | 2021-09-03 | 深圳市曼恩斯特科技股份有限公司 | Dry coating conveying rolling equipment |
| CN114824177A (en) * | 2022-03-24 | 2022-07-29 | 合肥国轩高科动力能源有限公司 | Preparation method of silicon negative electrode composite pole piece |
| CN114864860A (en) * | 2022-05-20 | 2022-08-05 | 三一技术装备有限公司 | Feeding mechanism, feeding device and dry-method electrode film preparation device |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2696138Y (en) * | 2003-11-05 | 2005-04-27 | 邝达辉 | Equipment for manufacturing electrode by dry process |
| CN1754237A (en) * | 2003-02-25 | 2006-03-29 | 日本瑞翁株式会社 | Process for producing electrode for electrochemical device |
| CN1988217A (en) * | 2005-12-20 | 2007-06-27 | 比亚迪股份有限公司 | Anode, lithium secondary battery including said anode and their preparing method |
| CN102881909A (en) * | 2011-07-13 | 2013-01-16 | 北京林业大学 | Defluorination carbon electrode and its preparation method |
| CN104241599A (en) * | 2013-06-18 | 2014-12-24 | 山东润峰集团新能源科技有限公司 | Method for preparing monomer lithium ion battery by adopting dry-method charging and rolling technique |
| CN105070879A (en) * | 2015-07-30 | 2015-11-18 | 河北中智电池制造有限公司 | Technology and equipment for manufacturing energy-saving and environment-friendly lithium battery pole piece |
| CN106129326A (en) * | 2016-08-30 | 2016-11-16 | 中航锂电（洛阳）有限公司 | A kind of preparation method of water system stack type lithium ion battery pole piece |
| CN107170953A (en) * | 2017-05-12 | 2017-09-15 | 西安工程大学 | A kind of warm therapy powdery electrode printed material and its preparation method for printing electrode |
| CN108365173A (en) * | 2018-02-08 | 2018-08-03 | 天津瑞晟晖能科技有限公司 | Electrode for secondary battery and preparation method thereof and secondary cell and preparation method thereof |
| US20190051888A1 (en) * | 2017-08-08 | 2019-02-14 | Toyota Jidosha Kabushiki Kaisha | Manufacturing method of negative electrode |
| CN208512925U (en) * | 2018-05-26 | 2019-02-19 | 江西省耐力科技股份有限公司 | A kind of lithium battery processing coating machine convenient for being segmented coating |
-
2019
- 2019-12-06 CN CN201911240475.7A patent/CN110828772B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1754237A (en) * | 2003-02-25 | 2006-03-29 | 日本瑞翁株式会社 | Process for producing electrode for electrochemical device |
| CN2696138Y (en) * | 2003-11-05 | 2005-04-27 | 邝达辉 | Equipment for manufacturing electrode by dry process |
| CN1988217A (en) * | 2005-12-20 | 2007-06-27 | 比亚迪股份有限公司 | Anode, lithium secondary battery including said anode and their preparing method |
| CN102881909A (en) * | 2011-07-13 | 2013-01-16 | 北京林业大学 | Defluorination carbon electrode and its preparation method |
| CN104241599A (en) * | 2013-06-18 | 2014-12-24 | 山东润峰集团新能源科技有限公司 | Method for preparing monomer lithium ion battery by adopting dry-method charging and rolling technique |
| CN105070879A (en) * | 2015-07-30 | 2015-11-18 | 河北中智电池制造有限公司 | Technology and equipment for manufacturing energy-saving and environment-friendly lithium battery pole piece |
| CN106129326A (en) * | 2016-08-30 | 2016-11-16 | 中航锂电（洛阳）有限公司 | A kind of preparation method of water system stack type lithium ion battery pole piece |
| CN107170953A (en) * | 2017-05-12 | 2017-09-15 | 西安工程大学 | A kind of warm therapy powdery electrode printed material and its preparation method for printing electrode |
| US20190051888A1 (en) * | 2017-08-08 | 2019-02-14 | Toyota Jidosha Kabushiki Kaisha | Manufacturing method of negative electrode |
| CN108365173A (en) * | 2018-02-08 | 2018-08-03 | 天津瑞晟晖能科技有限公司 | Electrode for secondary battery and preparation method thereof and secondary cell and preparation method thereof |
| CN208512925U (en) * | 2018-05-26 | 2019-02-19 | 江西省耐力科技股份有限公司 | A kind of lithium battery processing coating machine convenient for being segmented coating |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112802987A (en) * | 2020-12-31 | 2021-05-14 | 蜂巢能源科技有限公司 | Method for preparing electrode slice by dry rolling |
| CN112802987B (en) * | 2020-12-31 | 2022-04-29 | 蜂巢能源科技有限公司 | Method for preparing electrode slice by dry rolling |
| CN112652824A (en) * | 2021-01-21 | 2021-04-13 | 天津市捷威动力工业有限公司 | Cylindrical lithium ion battery manufacturing process |
| CN113333230A (en) * | 2021-06-03 | 2021-09-03 | 深圳市曼恩斯特科技股份有限公司 | Dry coating conveying rolling equipment |
| CN114824177A (en) * | 2022-03-24 | 2022-07-29 | 合肥国轩高科动力能源有限公司 | Preparation method of silicon negative electrode composite pole piece |
| CN114864860A (en) * | 2022-05-20 | 2022-08-05 | 三一技术装备有限公司 | Feeding mechanism, feeding device and dry-method electrode film preparation device |
| CN114864860B (en) * | 2022-05-20 | 2023-11-17 | 三一技术装备有限公司 | Feeding mechanism, feeding device and dry electrode film preparation device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110828772B (en) | 2020-11-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110828772B (en) | Dry preparation process of pole piece and continuous production equipment of pole piece | |
| CN106463697B (en) | Non-aqueous secondary battery laminated body and its manufacturing method and non-aqueous secondary battery | |
| CN102263298B (en) | Nickel-zinc secondary battery and preparation method thereof | |
| CN105742611B (en) | A kind of lithium ion battery negative material, preparation method and lithium ion battery | |
| CN109860720B (en) | Preparation method of composite electrolyte layer and solid-state battery | |
| CN103069612B (en) | Porous membrane for secondary battery, production method therefor, and use thereof | |
| CN108886136A (en) | The sulfur electrode and its manufacturing method of multizone | |
| CN104795541B (en) | Lithium-ion battery negative electrode slurry preparation method | |
| WO2019221056A1 (en) | Slurry for nonaqueous secondary battery, separator for nonaqueous secondary battery, electrode for nonaqueous secondary battery, stack for nonaqueous secondary battery, and nonaqueous secondary battery | |
| CN106233507B (en) | The manufacturing method of composite particles for electrochemical element electrode | |
| CN103907226A (en) | Electrode for electrochemical element | |
| CN102272982A (en) | Method for producing battery electrode | |
| JP6931464B2 (en) | Method of manufacturing the electrode body | |
| CN111354949B (en) | Lithium ion battery | |
| WO2024060545A1 (en) | Antistatic flash-spun composite non-woven fabric and preparation method therefor | |
| JP3851195B2 (en) | Battery electrode manufacturing drying apparatus and battery electrode manufacturing method | |
| JP6471697B2 (en) | Adhesive coating solution for current collector coating | |
| JP5723746B2 (en) | Lithium ion battery and manufacturing method thereof | |
| CN113871561A (en) | Preparation method of dry-method electrode pole piece, electrode pole piece and battery cell | |
| JPH09287006A (en) | Production of metallic sheet and metallic sheet produced by this method | |
| CN106537653A (en) | Method of manufacturing a lithium-ion secondary battery electrode sheet based on an active material dry powder | |
| CN111799437A (en) | Positive pole piece and sodium ion battery | |
| JP2018120817A (en) | Method for manufacturing battery | |
| JP6962235B2 (en) | Manufacturing method of positive electrode for lithium ion secondary battery | |
| CN103151491A (en) | Electrode and method for manufacturing same |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: A Dry Preparation Process for Poles and Continuous Production Equipment for Poles Effective date of registration: 20231125 Granted publication date: 20201110 Pledgee: Yuandong New Energy Co.,Ltd. Pledgor: LIANDONG TIANYI NEW ENERGY Co.,Ltd. Registration number: Y2023980066881 |