CN114171718A - Pole piece preparation method of composite foil current collector, pole piece and soft package battery - Google Patents
Pole piece preparation method of composite foil current collector, pole piece and soft package battery Download PDFInfo
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- CN114171718A CN114171718A CN202111285008.3A CN202111285008A CN114171718A CN 114171718 A CN114171718 A CN 114171718A CN 202111285008 A CN202111285008 A CN 202111285008A CN 114171718 A CN114171718 A CN 114171718A
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- 239000002131 composite material Substances 0.000 title claims abstract description 122
- 239000011888 foil Substances 0.000 title claims abstract description 119
- 238000002360 preparation method Methods 0.000 title claims abstract description 28
- 239000000126 substance Substances 0.000 claims abstract description 108
- 239000011267 electrode slurry Substances 0.000 claims abstract description 46
- 238000000576 coating method Methods 0.000 claims abstract description 37
- 238000000034 method Methods 0.000 claims abstract description 36
- 239000011248 coating agent Substances 0.000 claims abstract description 35
- 238000005520 cutting process Methods 0.000 claims abstract description 24
- 230000008569 process Effects 0.000 claims abstract description 11
- 238000001035 drying Methods 0.000 claims description 39
- 229910052751 metal Inorganic materials 0.000 claims description 28
- 239000002184 metal Substances 0.000 claims description 28
- 229920006254 polymer film Polymers 0.000 claims description 15
- 239000004020 conductor Substances 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 10
- 238000007731 hot pressing Methods 0.000 claims description 9
- 239000012528 membrane Substances 0.000 claims description 9
- 230000004048 modification Effects 0.000 claims description 9
- 238000012986 modification Methods 0.000 claims description 9
- 239000007784 solid electrolyte Substances 0.000 claims description 9
- 239000006258 conductive agent Substances 0.000 claims description 3
- 239000011344 liquid material Substances 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 238000002844 melting Methods 0.000 claims description 2
- 230000008018 melting Effects 0.000 claims description 2
- 229920000642 polymer Polymers 0.000 claims description 2
- 150000001875 compounds Chemical class 0.000 claims 1
- 238000003466 welding Methods 0.000 abstract description 12
- 229910052782 aluminium Inorganic materials 0.000 abstract description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 abstract description 8
- 238000004519 manufacturing process Methods 0.000 abstract description 8
- 239000002003 electrode paste Substances 0.000 description 17
- 238000005096 rolling process Methods 0.000 description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 6
- 239000004593 Epoxy Substances 0.000 description 6
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 6
- 239000011889 copper foil Substances 0.000 description 6
- 230000003247 decreasing effect Effects 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 238000002156 mixing Methods 0.000 description 5
- 229910052709 silver Inorganic materials 0.000 description 5
- 239000004332 silver Substances 0.000 description 5
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 4
- 230000001070 adhesive effect Effects 0.000 description 4
- 239000003292 glue Substances 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 229910052744 lithium Inorganic materials 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000010280 constant potential charging Methods 0.000 description 2
- 238000010277 constant-current charging Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
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- 238000013329 compounding Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012943 hotmelt Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
- H01M10/0583—Construction or manufacture of accumulators with folded construction elements except wound ones, i.e. folded positive or negative electrodes or separators, e.g. with "Z"-shaped electrodes or separators
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/665—Composites
- H01M4/667—Composites in the form of layers, e.g. coatings
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
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- Chemical & Material Sciences (AREA)
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- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Composite Materials (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Cell Electrode Carriers And Collectors (AREA)
Abstract
The invention discloses a preparation method of a pole piece of a composite foil current collector, the pole piece and a soft package battery, which comprises the following steps: s1, coating electrode slurry and a conductive substance on the surface of the composite foil current collector at intervals, wherein an uncoated area is reserved between the electrode slurry and the conductive substance, and the conductive substance has no viscosity at normal temperature and has viscosity after being heated; s2, cutting the composite foil current collector obtained in the step S1 into pole pieces with pole lugs, wherein the conductive substance and the uncoated area are located on the pole lug parts of the pole pieces; the composite foil current collector with lower surface density is adopted, so that the energy density of the battery can be effectively improved, the soft package battery adopting the pole piece and the preparation method ensures the electronic conduction between different composite aluminum foil pole pieces, the welding process is simplified, the cost is saved, and the production efficiency and the yield are improved.
Description
Technical Field
The invention relates to the field of lithium batteries, in particular to a preparation method of a pole piece by adopting a composite foil current collector, the pole piece and a soft package battery.
Background
In the production process of the lithium battery, a metal foil is usually selected as a current collector, wherein an aluminum foil is selected as a positive current collector, and a copper foil is selected as a negative current collector. In order to improve the energy density and safety of the battery, attention is paid to a composite current collector obtained by compounding a polymer film and a metal coating.
However, the polymer film is adopted in the middle of the composite current collector, the insulating layer formed by the polymer film enables metal coatings on two sides to be incapable of conducting, when the composite current collector tabs and the external tabs are welded, good contact and electronic connection cannot be formed between the metal coatings on the upper side and the lower side of the polymer film during conventional ultrasonic spot welding, therefore, good electric connection cannot be formed between the external tabs and the tabs of the multilayer composite current collector, current conduction in the battery is hindered, internal resistance of the battery is increased, even insulation between a positive electrode and a negative electrode of the battery is caused, and normal charging and discharging functions of the battery are affected.
The method commonly adopted at present is to clamp and weld the lugs of one layer of composite current collector by two layers of metal lugs, and then weld the multiple layers of metal lugs with the external lugs of the lithium battery respectively, thereby solving the problem of leading out the lugs of the composite current collector. However, by adopting the method, the tab part of each composite current collector needs to be coated and welded with two metal tabs, so that the number of layers of aluminum and copper foils needing to be welded is increased, the weight of the battery is increased, and the energy density of the battery is reduced. In addition, the current is conveyed out of the electrode by adopting the method, the welding process is complex, the quality is uneven, and the welding difficulty is increased and the yield is influenced after the composite current collector is used. More importantly, even if the welding is successful, the effective electronic conducting metal layer in the composite current collector has limited thickness, and the resistance is still higher than that of the conventional aluminum foil and copper foil under the same welding area, so that the power performance of the battery is influenced.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a pole piece preparation method adopting a composite foil current collector, a pole piece and a solution of a soft package battery, wherein the energy density of the battery can be effectively improved by adopting the composite foil current collector with lower surface mass density, and the soft package battery adopting the pole piece and the preparation method ensures the electronic conduction between different composite aluminum foil pole pieces, simplifies the welding process, saves the cost and improves the production efficiency and the yield.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a preparation method of a pole piece of a composite foil current collector comprises the following steps:
s1, coating electrode slurry and a conductive substance on the surface of the composite foil current collector at intervals, wherein an uncoated area is reserved between the electrode slurry and the conductive substance, and the conductive substance has no viscosity at normal temperature and has viscosity after being heated;
s2, cutting the composite foil current collector obtained in the step S1 into pole pieces with pole lugs, wherein the conductive substance and the uncoated area are located on the pole lug parts of the pole pieces;
or comprises the following steps:
a1, coating electrode slurry on the surface of the composite foil current collector and reserving a first blank area, and then drying;
a2, coating a conductive substance on a first white area of a composite foil current collector, and then drying again, wherein an uncoated area is left between the conductive substance and the electrode slurry, and the conductive substance has no viscosity at normal temperature and has viscosity after being heated;
a3, cutting the composite foil current collector obtained in the step A2 into pole pieces with pole lugs, wherein the conductive substance and the uncoated area are positioned on the pole lug parts of the pole pieces;
or comprises the following steps:
b1, coating a conductive substance on the surface of the composite foil current collector and leaving a second white region, and then drying, wherein the conductive substance has no viscosity at normal temperature and has viscosity after being heated;
b2, coating electrode slurry on a second blank area of the composite foil current collector, and then drying again, wherein an uncoated area is reserved between the electrode slurry and the conductive substance;
and B3, cutting the composite foil current collector obtained in the step B2 into pole pieces with pole lugs, wherein the conductive substance and the uncoated area are positioned on the pole lug parts of the pole pieces.
Preferably, the hot-melt temperature (modification temperature) of the conductive substance is higher than the drying temperature after the conductive substance is coated.
Preferably, the electrode paste is coated on the middle position of the surface of the composite foil material current collector, and the conductive substance is coated on at least one side of the electrode paste.
Preferably, the conductive substance is a mixture of a colloidal liquid material and an electron conductive agent.
Preferably, the ratio of the width of the uncoated region to the width of the conductive substance coated region is 1/9 to 9/1.
Preferably, the thickness of the coated conductive material after drying is 5 to 20 μm.
Preferably, the composite foil current collector comprises a polymer film positioned in the middle, and a first metal layer and a second metal layer which are respectively positioned on two sides of the polymer film in the thickness direction.
A pole piece of a composite foil current collector comprises the pole piece prepared by the method.
The utility model provides a laminate polymer battery, includes diaphragm or solid electrolyte membrane, external positive tab, external negative pole ear and a plurality of pole piece, and is a plurality of the pole piece corresponds respectively to positive plate and negative pole piece, positive plate with the crisscross overlapping setting of negative pole piece, diaphragm or solid electrolyte membrane coiling are the Z type, every positive plate with keep apart through diaphragm or solid electrolyte membrane between the negative pole piece, it is a plurality of hot-pressing bonding is in the same place after the utmost point ear coincide of positive plate, then is connected with external positive tab, and is a plurality of hot-pressing bonding is in the same place after the utmost point ear coincide of negative pole piece, then is connected with external negative pole ear.
Compared with the prior art, the pole piece preparation method of the composite foil current collector, the pole piece and the soft package battery have the advantages that,
1) the composite foil current collector with lower surface mass density is adopted, so that the energy density of the battery can be effectively improved;
2) after the lamination process, the multilayer current collectors are heated and pressed together, which is equivalent to the current collector welding process of common metal foil, compared with the welding connection of the common metal foil current collectors, the blank area is coated with a conductive substance which is non-adhesive at normal temperature and is sticky after heating, only slight improvement is made on the process, the preparation process of the pole piece and other related processes such as cutting are highly matched with the conventional process, no special equipment is needed, the problem that the existing composite foil current collector is difficult to weld is effectively solved, the cost is saved, the problem that the welding process of the composite foil current collector has uneven quality is also solved, and the production efficiency and the yield are improved;
3) through raw material screening, conductive substances which are not sticky at normal temperature and are sticky after being heated are coated in a white area, so that the pole piece is convenient to roll and store;
4) and a certain proportion of uncoated areas are left between the electrode slurry and the conductive substances, so that the adverse effect of high temperature on the diaphragm during hot pressing of the tabs is reduced, and the risks of lithium precipitation of the negative electrode and short circuit of the positive electrode and the negative electrode are avoided. More importantly, the setting of the uncoated region can be used for a tab folding process, the area of a battery top sealing region is reduced, and the energy density of the battery is improved.
Drawings
FIG. 1 is a first schematic structural diagram of a composite foil current collector coated with a conductive material and an electrode slurry;
FIG. 2 is a schematic view of a cut pole piece;
FIG. 3 is a schematic cross-sectional view of a composite foil current collector coated with a conductive material and an electrode paste;
FIG. 4 is a second schematic structural view of the composite foil current collector coated with the conductive material and the electrode slurry;
FIG. 5 is a third schematic view of the composite foil current collector coated with a conductive material and an electrode slurry;
fig. 6 is a fourth schematic structural view of the composite foil current collector coated with the conductive material and the electrode slurry.
In the figure, 1, a composite foil current collector; 11. a polymer film; 12. a first metal layer; 13. a second metal layer; 2. electrode paste; 3. a conductive substance; 4. an uncoated zone.
Detailed Description
The invention is described in further detail below with reference to the accompanying examples.
Examples 1,
A preparation method of a pole piece of a composite foil current collector comprises the following steps:
s1, coating electrode slurry 2 and conductive substances 3 on the surface of the composite foil current collector 1 at intervals, leaving an uncoated area 4 between the electrode slurry 2 and the conductive substances 3, drying the composite foil current collector 1 coated with the electrode slurry 2 and the conductive substances 3, and then rolling;
and S2, cutting the composite foil current collector obtained in the step S1 into pole pieces with pole lugs, wherein the conductive substance 3 and the uncoated area 4 are positioned on the pole lug parts of the pole pieces.
The conductive substance 3 is a mixture of a colloidal liquid material and an electron conductive agent, the conductive substance 3 is non-adhesive at normal temperature and adhesive after heating, and the hot melting temperature (modification temperature) of the conductive substance 3 is higher than the drying temperature of the conductive substance 3 after coating.
The composite foil current collector 1 comprises a polymer film 11 positioned in the middle, and a first metal layer 12 and a second metal layer 13 respectively positioned on two sides of the polymer film 11 in the thickness direction. Both the electrode paste 2 and the conductive substance 3 are applied along the extending direction (longitudinal direction) or the width direction of the composite foil current collector 1.
The ratio of the width of the uncoated area 4 to the width of the area coated with the conductive substance 3 is 1/9-9/1, preferably 1/4-4/1, particularly 2/5, the ratio is too small, the folding of the tabs is not facilitated, or the contraction of the diaphragm caused by hot pressing is not facilitated, the ratio is too high, and the effective area of electronic contact is low. The thickness of the coated conductive substance 3 after drying is 5 μm to 20 μm, preferably 8 μm to 16 μm, and particularly 12 μm, and too thick affects the electronic conductivity, and too thin adhesive strength is not required.
The uncoated area 4 is provided with an initial position, a cutter of the cutting equipment starts cutting from the initial position, cuts according to the shape of a preset pole piece and returns to the initial position to form a pole piece with a pole lug; or cutting the pole piece with the pole lug for multiple times by one or more cutters of the cutting equipment to form a pole piece with the pole lug; or simultaneously cutting the pole pieces by a plurality of cutters of the cutting equipment to form a pole piece with a pole lug.
It should be understood by those skilled in the art that the step S1 of applying the electrode paste 2 and the conductive substance 3 on the surface of the composite foil current collector 1 at intervals includes applying the electrode paste 2 and then applying the conductive substance 3, applying the conductive substance 3 and then applying the electrode paste 2, and applying the electrode paste 2 and the conductive substance 3 at the same time.
Fig. 1 is a schematic structural diagram of a composite foil current collector coated with a conductive material 3 and electrode slurry; FIG. 2 is a schematic view of a cut pole piece; fig. 3 is a schematic cross-sectional view of the composite foil current collector coated with the conductive substance 3 and the electrode slurry.
Examples 2,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 1 is that:
the method comprises the following steps:
a1, coating electrode slurry 2 on the surface of a composite foil current collector 1 and reserving a first blank area, and then drying and rolling;
a2, coating a conductive substance 3 on a first white area of a composite foil current collector 1, drying and rolling again, leaving an uncoated area 4 between the conductive substance 3 and the electrode slurry 2, wherein the conductive substance 3 has no viscosity at normal temperature and has viscosity after heating;
and A3, cutting the composite foil current collector 1 obtained in the step A2 into pole pieces with pole lugs, wherein the conductive substance 3 and the uncoated area 4 are positioned at the pole lug parts of the pole pieces.
Examples 3,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 1 is that:
the method comprises the following steps:
b1, coating a conductive substance 3 on the surface of the composite foil current collector 1 and leaving a second white region, then drying and rolling, wherein the conductive substance 3 has no viscosity at normal temperature and has viscosity after heating;
b2, coating the electrode slurry 2 on a second blank area of the composite foil current collector 1, drying and rolling again, and leaving an uncoated area 4 between the electrode slurry 2 and the conductive substance 3;
and B3, cutting the composite foil current collector 1 obtained in the step B2 into pole pieces with pole lugs, wherein the conductive substance 3 and the uncoated area 4 are positioned at the pole lug parts of the pole pieces.
Examples 4,
A preparation method of a pole piece of a composite foil current collector comprises the following steps:
s1, a roll of composite foil is taken, a coater is utilized to coat electrode paste 2 on the surface of the composite foil along the length direction of the composite foil, a conductive substance 3 is coated on one side of the electrode paste 2, an uncoated area 4 is reserved between the electrode paste 2 and the conductive substance 3, and the composite foil current collector 1 coated with the electrode paste 2 and the conductive substance 3 is dried and then is rolled;
and S2, cutting the composite foil current collector 1 obtained in the step S1 into pole pieces with pole lugs, wherein the conductive substance 3 and the uncoated area 4 are positioned at the pole lug parts of the pole pieces.
The thickness of the composite aluminum foil is 8 micrometers, the thickness of the polymer film 11 is 6 micrometers, the thickness of the first metal layer 12 is 1 micrometer, the thickness of the second metal layer 13 is 1 micrometer, the thickness of the composite copper foil is 7 micrometers, the thickness of the polymer film 11 is 6 micrometers, the thickness of the first metal layer 12 is 0.5 micrometer, and the thickness of the second metal layer 13 is 0.5 micrometer. The width of the uncoated area 4 was 6mm, the width of the area coated with the conductive substance 3 was 15mm, the tab width of the cut pole piece was 21mm, and the thickness of the coated conductive substance 3 after drying was 12 μm.
The conductive substance 3 is a mixture of epoxy conductive silver glue and AB, the mixing ratio is 1:1, the modification temperature of the conductive substance 3 is 180 ℃, and the drying temperature in the step S2 is 120 ℃.
Examples 5,
A preparation method of a pole piece of a composite foil current collector comprises the following steps:
a1, taking a roll of composite foil, coating electrode slurry 2 on the surface of the composite foil along the length direction of the composite foil by using a coating machine, reserving a first blank region, and then drying and rolling, wherein the drying temperature is 120 ℃;
a2, coating a conductive substance 3 in a first remaining white area of a composite foil current collector 1 along the extension direction of the composite foil, and then drying and rolling again, wherein the drying temperature is 120 ℃, and an uncoated area 4 is left between the conductive substance 3 and the electrode slurry 2;
and A3, cutting the composite foil current collector 1 obtained in the step A2 into pole pieces with pole lugs, wherein the conductive substance 3 and the uncoated area 4 are positioned at the pole lug parts of the pole pieces.
The selection of the composite foil, the width of the uncoated region 4, the selection of the conductive substance 3, and the coating width and thickness are the same as those of example 4.
Examples 6,
A preparation method of a pole piece of a composite foil current collector comprises the following steps:
b1, taking a roll of composite foil, coating a conductive substance 3 on the surface of the composite foil along the length direction of the composite foil by using a coating machine, reserving a second reserved area, and then drying at the drying temperature of 120 ℃;
b2, coating electrode slurry 2 in a second remaining area of the composite foil current collector 1 along the extension direction of the composite foil, and then drying again at the drying temperature of 120 ℃, wherein an uncoated area 4 is reserved between the electrode slurry 2 and the conductive substance 3;
and B3, cutting the composite foil current collector 1 coated with the electrode slurry 2 and the conductive substance 3 into a pole piece with a pole lug, wherein the conductive substance 3 and the uncoated area 4 are positioned at the pole lug part of the pole piece.
The selection of the composite foil, the width of the uncoated region 4, the selection of the conductive substance 3, and the coating width and thickness are the same as those of example 4.
Example 7,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 4 is that the width of an uncoated area 4 is 2.1mm, the width of an area coated with a conductive substance 3 is 18.9mm, and the width of a pole lug of the cut pole piece is 21 mm.
Example 8,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 4 is that the width of an uncoated area 4 is 18.9mm, the width of an area coated with a conductive substance 3 is 2.1mm, and the width of a pole lug of the cut pole piece is 21 mm.
Examples 9,
A method for preparing a pole piece of a composite foil current collector, which is different from the method in example 4 in that the thickness of a coated conductive substance 3 after drying is 5 μm.
Examples 10,
A method for preparing a pole piece of a composite foil current collector, which is different from the method in example 4 in that the thickness of a coated conductive substance 3 after drying is 20 μm.
Examples 11,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 4 is that the conductive substance is a mixture of epoxy conductive silver colloid and AB, and the mixing ratio is 1: 2.
Examples 12,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 4 is that the conductive substance is a mixture of epoxy conductive silver glue and SP, the mixing ratio is 1:1, the modification temperature of the conductive substance is 175 ℃, and the drying temperature in the step S2 is 120 ℃.
Examples 13,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 4 is that the conductive substance is a mixture of epoxy conductive silver glue and SP, the mixing ratio is 1:2, the modification temperature of the conductive substance is 175 ℃, and the drying temperature in the step S2 is 120 ℃.
Examples 14,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 4 is that the conductive substance is a mixture of epoxy conductive silver glue and CNT, the mixing ratio is 1:1, the modification temperature of the conductive substance is 175 ℃, and the drying temperature in the step S2 is 120 ℃.
Examples 15,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 4 is that the electrode slurry 2 is coated on the middle position of the surface of the composite foil current collector 1, and the conductive substance 3 is coated on the two sides of the electrode slurry 2, as shown in fig. 4, when cutting, the middle of the electrode slurry 2 on the composite foil current collector 1 is cut, and then a plurality of electrode pieces with one tab are cut.
Examples 16,
The difference between the preparation method of the pole piece of the composite foil current collector and the embodiment 4 is that the electrode slurry 2 is coated on two sides of the surface of the composite foil current collector 1, the conductive substance 3 is coated in the middle of the two electrode slurries 2, and as shown in fig. 5, when cutting, the electrode plates are cut from the initial position to the initial position according to the preset pole piece shape, so that a plurality of electrode plates with one pole lug are formed, the electrode plates on two sides share the conductive substance 3 in the middle, and the material can be effectively saved.
Examples 17,
A method for preparing a pole piece of a composite foil current collector, which is different from that in example 4, electrode paste 2 and a conductive substance 3 are coated at intervals along the width direction of a composite foil current collector 1, and the conductive substance 3 is coated on two sides of the electrode paste 2, as shown in fig. 6.
Examples 18,
A pole piece of a composite foil current collector, comprising a pole piece prepared by the method of embodiments 1-17 above.
Examples 19,
A soft package battery comprises a diaphragm or a solid electrolyte membrane, an external positive electrode tab, an external negative electrode tab and a plurality of pole pieces manufactured by the method of the embodiment 1-17, wherein the pole pieces are respectively a positive plate and a negative plate, the positive plate and the negative plate are arranged in a staggered and overlapped mode, the diaphragm or the solid electrolyte membrane is wound to be in a Z shape, each positive plate is isolated from the negative plate through the diaphragm or the solid electrolyte membrane, the pole tabs of the positive plates are bonded together in a hot pressing mode after being overlapped, and then are connected with the external positive electrode tab, and the pole tabs of the negative plates are bonded together in a hot pressing mode after being overlapped and then are connected with the external negative electrode tab.
Comparative examples 1,
A preparation method of a pole piece of a composite foil current collector comprises the following steps:
s1, coating electrode slurry on the surface of the composite foil current collector, and reserving a blank area on one side of the electrode slurry;
and S2, drying the composite foil current collector coated with the electrode slurry, cutting into pole pieces with pole lugs, and enabling the blank areas to be located on the pole lug parts of the pole pieces.
The thickness of the composite aluminum foil is 8 micrometers, the thickness of the polymer film 11 is 6 micrometers, the thickness of the first metal layer 12 is 1 micrometer, the thickness of the second metal layer 13 is 1 micrometer, the thickness of the composite copper foil is 7 micrometers, the thickness of the polymer film 11 is 6 micrometers, the thickness of the first metal layer 12 is 0.5 micrometer, the thickness of the second metal layer 13 is 0.5 micrometer, and the width of a tab of the cut pole piece is 21 mm.
When the electrode plate prepared by the method is used for manufacturing a battery, metal sheets are welded on two sides of the electrode plate and then welded with external tabs, and current is led out.
Comparative examples 2,
A preparation method of a pole piece comprises the following steps:
s1, coating electrode slurry on the surface of a 12-micron aluminum foil current collector or an 8-micron copper foil current collector, and reserving a white area on one side of the electrode slurry;
and S2, drying the metal foil current collector coated with the electrode slurry, cutting into pole pieces with pole lugs, and enabling the blank areas to be located on the pole lug parts of the pole pieces.
Test examples,
Soft package battery internal resistance, energy density increasing rate, battery capacity retention rate and yield test
Pouch batteries comprising positive and negative electrode sheets prepared using the methods of examples 4-14, each containing 100 parallel samples.
The detection method of the internal resistance of the battery comprises the following steps: the battery internal resistance tester is used for testing the internal resistance of the battery after the battery is fully charged (the battery is charged to 4.2V by 0.33C constant current and then is charged by constant voltage until the current is reduced to 0.05C), and the frequency of an alternating current signal is set to be 1 KHz.
The method for testing the energy density increasing rate and the battery capacity retention rate comprises the following steps: using a battery charge-discharge tester to perform charge-discharge cycle test on the battery at 25 ℃, wherein the charge-discharge system comprises the following steps: (0.33C constant current charging to 4.2V, then constant voltage charging to current reduction to 0.05C, after 5 min of standing, the battery was discharged to 3.0V at 0.33C constant current, this is 1 cycle, the number of cycles of the battery charge and discharge tester was set to 3 times, finally the average of the three discharge capacities was taken as the discharge capacity of 0.33C, the average of the three discharge energies was taken as the discharge energy of 0.33C, the discharge energy of 0.33C was divided by the mass as the mass energy density, further the mass energy density of the example was divided by the mass energy density of comparative example 2 as the energy density boost rate, then 1.0C constant current charging to 4.2V, then constant voltage charging to current reduction to 0.05C, after 5 min of standing, the battery was discharged to 3.0V at 1.0C constant current, this is 1 cycle, the number of cycles of the battery charge and discharge tester was set to 3 times, finally, taking the average value of the tertiary discharge capacity as the discharge capacity of 1.0C; the discharge capacity at 1.0C was divided by the discharge capacity at 0.33C as the capacity retention rate. ) As the battery cycles, the battery capacity decays, and the number of cycles that the battery undergoes when the capacity decays to 80% of the first discharge capacity is recorded as the cycle life of the battery. Each example contains 100 parallel samples, and the yield is counted.
In example 7, the coated region of the conductive material was widened, and the internal resistance was decreased, but the coated region was too wide, which resulted in self-discharge of 3 batteries due to micro-short circuit, and the yield was rather decreased. In example 8, decreasing the coating area of the conductive substance resulted in an increase in internal resistance and a decrease in capacity retention rate; meanwhile, the bonding area is too small, so that poor bonding is caused, and the yield is only 90%.
In example 9, the thickness of the conductive material after drying was reduced, and the internal resistance was reduced, but the conductive material was too thin, which resulted in poor contact of 5 batteries. In contrast, in example 10, since the conductive material was too thick after drying, the internal resistance increased and the power performance decreased, but the adhesiveness was good and the yield was not affected.
In example 11, the amount of AB increased, and the conductivity was better, but the amount of the epoxy conductive silver paste decreased, and the adhesiveness was deteriorated, and the yield was reduced to 92%.
Examples 12 and 14 changed the mixture to SP and CNT, respectively, and the internal resistance was gradually decreased due to the conductive CNT > SP > AB. In example 13, the ratio of the mixture was changed to 1:2 in addition to example 12, and the yield was reduced for the same reason as in example 11, but since the conductivity of SP was better than that of AB, the yield was 97% higher than that of example 11.
From the above experiments, it can be known that the conductive substance and the electrode paste are both coated and then dried or are respectively coated and dried, which has little influence on the internal resistance and the cycle life of the battery, but the production period can be greatly shortened and the efficiency can be improved by coating and then drying the conductive substance and the electrode paste.
The coating thickness of the conductive substance 3 influences, and when the thickness of the conductive substance 3 coating is selected, the reasonable thickness can improve various performances of the battery.
The width of the uncoated region 4 is too large, the conductive performance is deteriorated, the width of the region coated with the conductive substance is too large, short-circuit self-discharge is caused, and the ratio of the width of the uncoated region 4 to the width of the region coated with the conductive substance 3 is 2/5 optimal.
Compared with the prior art, the pole piece preparation method adopting the composite foil current collector 1, the pole piece and the soft package battery have the advantages that after the pole piece is connected with a 100-battery test production in a hot pressing mode, the finding is that when the optimal coating area width ratio, the coating thickness of the conductive substance and the ratio of the conductive substance are adopted, the yield reaches 100%, and the yield is obviously improved by comparing with the yield of 65% in the previous welding mode, the operation is simple compared with the welding mode, and the production efficiency can be improved.
Although preferred embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that modifications and variations of the present invention are possible to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (9)
1. A preparation method of a pole piece of a composite foil current collector is characterized by comprising the following steps: the method comprises the following steps:
s1, coating electrode slurry and a conductive substance on the surface of the composite foil current collector at intervals, wherein an uncoated area is reserved between the electrode slurry and the conductive substance, and the conductive substance has no viscosity at normal temperature and has viscosity after being heated;
s2, cutting the composite foil current collector obtained in the step S1 into pole pieces with pole lugs, wherein the conductive substance and the uncoated area are located on the pole lug parts of the pole pieces;
or comprises the following steps:
a1, coating electrode slurry on the surface of the composite foil current collector and reserving a first blank area, and then drying;
a2, coating a conductive substance on a first white area of a composite foil current collector, and then drying again, wherein an uncoated area is left between the conductive substance and the electrode slurry, and the conductive substance has no viscosity at normal temperature and has viscosity after being heated;
a3, cutting the composite foil current collector obtained in the step A2 into pole pieces with pole lugs, wherein the conductive substance and the uncoated area are positioned on the pole lug parts of the pole pieces;
or comprises the following steps:
b1, coating a conductive substance on the surface of the composite foil current collector and leaving a second white region, and then drying, wherein the conductive substance has no viscosity at normal temperature and has viscosity after being heated;
b2, coating electrode slurry on a second blank area of the composite foil current collector, and then drying again, wherein an uncoated area is reserved between the electrode slurry and the conductive substance;
and B3, cutting the composite foil current collector obtained in the step B2 into pole pieces with pole lugs, wherein the conductive substance and the uncoated area are positioned on the pole lug parts of the pole pieces.
2. The method for preparing a pole piece of a composite foil current collector according to claim 1, wherein the method comprises the following steps: the hot melting temperature (modification temperature) of the conductive substance is higher than the drying temperature of the conductive substance after coating.
3. The method for preparing a pole piece of a composite foil current collector according to claim 2, wherein: the electrode slurry is coated on the middle position of the surface of the composite foil material current collector, and the conductive substance is coated on at least one side of the electrode slurry.
4. The method for preparing a pole piece of a composite foil current collector according to claim 2, wherein: the conductive substance is a mixture of a colloidal liquid material and an electron conductive agent.
5. The method for preparing a pole piece of a composite foil current collector according to claim 2, wherein: the ratio of the width of the uncoated area to the width of the conductive substance coated area is 1/9-9/1.
6. The method for preparing a pole piece of a composite foil current collector according to claim 2, wherein: the thickness of the coated conductive material after drying is 5-20 μm.
7. The method for preparing a pole piece of a composite foil current collector according to claim 1, wherein the method comprises the following steps: the composite foil current collector comprises a middle high polymer film, and a first metal layer and a second metal layer which are respectively located on two sides of the high polymer film in the thickness direction.
8. The utility model provides a pole piece of compound foil mass flow body which characterized in that: comprising a pole piece prepared by the process of any one of the preceding claims 1 to 7.
9. The utility model provides a laminate polymer battery which characterized in that: including diaphragm or solid electrolyte membrane, external positive tab, external negative pole ear and a plurality of pole pieces in claim 8, it is a plurality of the pole piece corresponds respectively to positive plate and negative pole piece, positive plate with the crisscross overlapping setting of negative pole piece, diaphragm or solid electrolyte membrane coiling are the Z type, every positive plate with keep apart through diaphragm or solid electrolyte membrane between the negative pole piece, it is a plurality of hot-pressing bonding together behind the utmost point ear coincide of positive plate, then be connected with external positive tab, it is a plurality of hot-pressing bonding together behind the utmost point ear coincide of negative pole piece, then be connected with external negative pole ear.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114613943A (en) * | 2022-03-22 | 2022-06-10 | 上海兰钧新能源科技有限公司 | Pole piece, battery cell, pole piece preparation process and battery cell preparation process |
| CN115870560A (en) * | 2022-12-30 | 2023-03-31 | 重庆太蓝新能源有限公司 | Cutting mechanism and packaging method |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060188777A1 (en) * | 2003-07-31 | 2006-08-24 | Hiroshi Kaneta | Lithium ion secondary cell |
| CN105244506A (en) * | 2015-10-15 | 2016-01-13 | 青岛领军节能与新材料研究院 | Lithium-ion battery material and lithium-ion battery structure and preparation method of lithium-ion battery material |
| CN110828775A (en) * | 2019-10-15 | 2020-02-21 | 江苏卓高新材料科技有限公司 | Current collector electrode structure, secondary battery and preparation method of secondary battery |
| CN111712946A (en) * | 2018-06-20 | 2020-09-25 | 株式会社Lg化学 | Electrode assembly having improved connection structure between electrode tab and current collector and method of manufacturing the same |
| CN112216842A (en) * | 2019-07-12 | 2021-01-12 | 宁德新能源科技有限公司 | Composite current collector, electrode pole piece and battery cell comprising same |
| CN212810346U (en) * | 2020-04-29 | 2021-03-26 | 蜂巢能源科技有限公司 | Pole piece, battery cell and battery thereof |
| CN112909265A (en) * | 2021-03-26 | 2021-06-04 | 厦门海辰新能源科技有限公司 | Pole piece and cylindrical battery roll core structure |
| CN112928281A (en) * | 2021-03-23 | 2021-06-08 | 华中科技大学 | Ear-free cylindrical battery and preparation method thereof |
| CN214068854U (en) * | 2020-12-02 | 2021-08-27 | 东莞凯德新能源有限公司 | Negative pole drainage structure of full utmost point ear battery |
| CN113410421A (en) * | 2021-06-07 | 2021-09-17 | 万向一二三股份公司 | Positive electrode plate, manufacturing method thereof and lithium ion battery |
| CN113488659A (en) * | 2021-06-30 | 2021-10-08 | 浙江锋锂新能源科技有限公司 | Negative current collector complex, preparation method thereof and lithium metal battery |
-
2021
- 2021-11-01 CN CN202111285008.3A patent/CN114171718B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060188777A1 (en) * | 2003-07-31 | 2006-08-24 | Hiroshi Kaneta | Lithium ion secondary cell |
| CN105244506A (en) * | 2015-10-15 | 2016-01-13 | 青岛领军节能与新材料研究院 | Lithium-ion battery material and lithium-ion battery structure and preparation method of lithium-ion battery material |
| CN111712946A (en) * | 2018-06-20 | 2020-09-25 | 株式会社Lg化学 | Electrode assembly having improved connection structure between electrode tab and current collector and method of manufacturing the same |
| CN112216842A (en) * | 2019-07-12 | 2021-01-12 | 宁德新能源科技有限公司 | Composite current collector, electrode pole piece and battery cell comprising same |
| CN110828775A (en) * | 2019-10-15 | 2020-02-21 | 江苏卓高新材料科技有限公司 | Current collector electrode structure, secondary battery and preparation method of secondary battery |
| CN212810346U (en) * | 2020-04-29 | 2021-03-26 | 蜂巢能源科技有限公司 | Pole piece, battery cell and battery thereof |
| CN214068854U (en) * | 2020-12-02 | 2021-08-27 | 东莞凯德新能源有限公司 | Negative pole drainage structure of full utmost point ear battery |
| CN112928281A (en) * | 2021-03-23 | 2021-06-08 | 华中科技大学 | Ear-free cylindrical battery and preparation method thereof |
| CN112909265A (en) * | 2021-03-26 | 2021-06-04 | 厦门海辰新能源科技有限公司 | Pole piece and cylindrical battery roll core structure |
| CN113410421A (en) * | 2021-06-07 | 2021-09-17 | 万向一二三股份公司 | Positive electrode plate, manufacturing method thereof and lithium ion battery |
| CN113488659A (en) * | 2021-06-30 | 2021-10-08 | 浙江锋锂新能源科技有限公司 | Negative current collector complex, preparation method thereof and lithium metal battery |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114613943A (en) * | 2022-03-22 | 2022-06-10 | 上海兰钧新能源科技有限公司 | Pole piece, battery cell, pole piece preparation process and battery cell preparation process |
| CN114613943B (en) * | 2022-03-22 | 2024-03-29 | 上海兰钧新能源科技有限公司 | Pole piece, battery cell, pole piece preparation process and battery cell preparation process |
| CN115870560A (en) * | 2022-12-30 | 2023-03-31 | 重庆太蓝新能源有限公司 | Cutting mechanism and packaging method |
| CN115870560B (en) * | 2022-12-30 | 2024-01-26 | 重庆太蓝新能源有限公司 | Cutting mechanism and packaging method |
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|---|---|
| CN114171718B (en) | 2024-03-19 |
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