WO2020073887A1

WO2020073887A1 - Secondary battery and manufacturing method therefor, electrode component and manufacturing method therefor, and manufacturing method for current collector

Info

Publication number: WO2020073887A1
Application number: PCT/CN2019/109961
Authority: WO
Inventors: 梁成都; 张子格; 薛庆瑞; 李伟; 李静; 王鹏翔
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2018-10-11
Filing date: 2019-10-08
Publication date: 2020-04-16
Also published as: CN208955108U; JP2022504655A; KR20210062594A; JP2023055730A; JP7212773B2

Abstract

The present invention provides a secondary battery and a manufacturing method therefor, an electrode component and a manufacturing method therefor, and a manufacturing method for a current collector. The electrode component comprises an insulation substrate, a first conductive layer and an active substance layer; the first conductive layer is arranged on the surface of the insulation substrate, and the active substance layer is arranged on the side, away from the insulation substrate, of the first conductive layer; and the first conductive layer is provided with a strip-shaped groove extending in a height direction, and the strip-shaped groove is used for releasing stress on the first conductive layer. The secondary battery comprises an electrode assembly, and the electrode assembly comprises the electrode component.

Description

Secondary battery and manufacturing method thereof, electrode member and manufacturing method thereof, and current collector manufacturing method

Technical field

The present invention relates to the field of batteries, and in particular, to a secondary battery and a method for manufacturing the same, an electrode member and a method for manufacturing the same, and a method for manufacturing a current collector.

Background technique

The electrode member of a secondary battery generally includes a current collector and an active material layer coated on the surface of the current collector. In order to improve the safety performance of the secondary battery, some electrode members select a multi-layer structure current collector. Referring to FIGS. 1 to 3, the current collector includes an insulating base 11 and a conductive layer 12 connected to the surface of the insulating base 11, The active material layer 13 is coated on the surface of the conductive layer 12.

In the production process of the electrode member, it is necessary to roll the active material layer 13 to thin the active material layer 13 and increase the energy density. The insulating substrate 11 is a soft material (such as PET plastic), and the conductive layer 12 is usually made of metal. The elastic modulus of the insulating substrate 11 is smaller than that of the conductive layer 12, so the ductility of the insulating substrate 11 is higher than The ductility of the conductive layer 12. During the extension of the insulating substrate 11, the insulating substrate 11 exerts a force on the conductive layer 12, and since the connection force between the insulating substrate 11 and the conductive layer 12 is small, when the conductive layer 12 extends to a certain extent, The conductive layer 12 may be detached from the surface of the insulating base 11, thereby affecting the performance of the electrode member.

Summary of the invention

In view of the problems in the background art, the object of the present invention is to provide a secondary battery and its manufacturing method, electrode member and its manufacturing method, and current collector manufacturing method, which can reduce stress concentration and reduce the risk of the conductive layer falling , To ensure the performance of the electrode member.

In order to achieve the above object, the present invention provides an electrode member of a secondary battery.

The electrode member includes an insulating substrate, a first conductive layer, and an active material layer. The first conductive layer is provided on the surface of the insulating base, and the active material layer is provided on a side of the first conductive layer away from the insulating base. The first conductive layer is provided with a strip-shaped groove extending in the height direction.

The electrode member further includes a second conductive layer having a first portion located in the strip-shaped groove.

The second conductive layer further includes a second portion, the second portion is disposed on a surface of the first conductive layer away from the insulating substrate and connected to the first portion, and the active material layer is disposed on the first Two parts of the surface away from the first conductive layer.

The first conductive layer includes a body portion and a protrusion extending from the body portion, the body portion is coated with the active material layer, and the protrusion is not coated with the active material layer. The strip-shaped groove includes a first groove formed in the protrusion, and the second portion is at least partially located on a surface of the protrusion away from the insulating base.

The bar-shaped groove further includes a second groove formed in the body portion, and the first groove communicates with the second groove.

The electrode member further includes a protective layer provided on a surface of the second portion away from the protrusion and connected to the active material layer, and the first groove does not exceed the protective layer.

The rigidity of the second conductive layer is less than the rigidity of the first conductive layer.

The strip-shaped groove penetrates the first conductive layer in the thickness direction, and the first portion of the second conductive layer is connected to the insulating base.

There are a plurality of strip-shaped grooves, and the plurality of strip-shaped grooves are arranged at intervals in the width direction.

In order to achieve the above object, the present invention also provides a secondary battery. The secondary battery includes an electrode assembly including the electrode member.

In order to achieve the above object, the present invention also provides a method for manufacturing a current collector. The manufacturing method of the current collector includes: providing an insulating base; fixing a conductive material to the surface of the insulating base to form a first conductive layer, and the first conductive layer is provided with a strip-shaped groove extending in a height direction.

The conductive material is fixed to the surface of the insulating substrate by vapor deposition or chemical plating.

The manufacturing method of the current collector further includes: applying a conductive paste to a part of the surface of the first conductive layer, and filling the conductive paste into the strip-shaped groove. After the conductive paste is cured, a second conductive layer is formed.

In order to achieve the above object, the present invention also provides a method for manufacturing an electrode member. The manufacturing method of the electrode member includes: providing a current collector manufactured according to the current collector manufacturing method; applying a slurry including an active material to a partial area of the surface of the first conductive layer, and allowing the The slurry including the active material is filled into the strip-shaped groove; the slurry including the active material is cured to form an active material layer, and then the active material layer is rolled; the metal foil is welded to the first A region of a conductive layer not coated with the active material layer; a part of the metal foil and a part of the current collector are cut off to form a plurality of spaced-apart conductive structures and a plurality of spaced-apart electrical guides.

The method for manufacturing the electrode member further includes: applying a slurry including an insulating material to a partial area of the surface of the first conductive layer, the slurry including the insulating material curing to form a protective layer; the protective layer It is formed before welding the metal foil.

In order to achieve the above object, the present invention also provides a method for manufacturing a secondary battery. The manufacturing method of the secondary battery includes: providing a positive electrode member, a negative electrode member, and a separator, and winding the positive electrode member, the separator, and the negative electrode member together to form an electrode assembly, wherein the positive electrode member and At least one of the negative electrode members is manufactured according to the manufacturing method of the electrode member; providing an adapter sheet, laminating and welding a plurality of conductive structures of the electrode assembly to the adapter sheet; providing a top cover plate and fixing to Electrode terminal of the top cover plate, and welding the adapter piece to the electrode terminal; providing a housing, placing the electrode assembly into the housing, and then connecting the top cover plate to the housing .

In order to achieve the above object, the present invention also provides another method for manufacturing an electrode member. The manufacturing method of the electrode member includes: providing a current collector manufactured by the current collector manufacturing method; applying a slurry including an active material to a partial area of the surface of the second conductive layer; curing the including Slurry of active material and form an active material layer, and then roll the active material layer; weld a metal foil to an area of the first conductive layer not coated with the second conductive layer; cut off the metal foil A part of the material and a part of the current collector form a plurality of spaced-apart conductive structures and a plurality of spaced-apart electrical guides.

The manufacturing method of the electrode member further includes: applying a slurry including an insulating material to a part of the surface of the second conductive layer, and then curing the slurry including the insulating material and forming a protective layer. The protective layer is formed before welding the metal foil.

In order to achieve the above object, the present invention also provides another method for manufacturing a secondary battery. The manufacturing method of the secondary battery includes: providing a positive electrode member, a negative electrode member, and a separator, and winding the positive electrode member, the separator, and the negative electrode member together to form an electrode assembly, wherein the positive electrode member and At least one of the negative electrode members is manufactured according to the another method of manufacturing the electrode member; providing a transition piece, laminating and welding a plurality of conductive structures of the electrode assembly to the transition piece; providing A top cover plate and an electrode terminal fixed to the top cover plate, and welding the adapter piece to the electrode terminal; providing a case, placing the electrode assembly into the case, and then placing the top cover plate Connected to the housing.

The beneficial effects of the present invention are as follows: In this application, a strip-shaped groove is formed on the first conductive layer, and the strip-shaped groove can effectively release the force on the first conductive layer, reduce stress concentration, and effectively The risk of the first conductive layer falling off the surface of the insulating substrate ensures the performance of the electrode member.

BRIEF DESCRIPTION

FIG. 1 is a schematic diagram of an electrode member in the prior art.

FIG. 2 is a schematic diagram of the electrode member of FIG. 1 during the rolling process.

FIG. 3 is a schematic diagram of the insulating substrate and the conductive layer of the electrode member of FIG. 1 before being rolled.

FIG. 4 is a schematic diagram of the insulating substrate and the conductive layer of the electrode member of FIG. 1 after being rolled.

5 is a schematic diagram of a secondary battery according to the present invention.

6 is a cross-sectional view of an electrode assembly according to the present invention.

7 is a schematic diagram of a first embodiment of an electrode member according to the present invention.

8 is a cross-sectional view taken along line A-A of FIG. 7.

FIG. 9 is a schematic diagram of the electrode member of FIG. 7 during the molding process.

FIG. 10 is another schematic diagram of the electrode member of FIG. 7 during the molding process.

11 is a schematic diagram of the first conductive layer of FIG. 10 after being rolled.

FIG. 12 is another schematic diagram of the electrode member of FIG. 7 during the molding process.

13 is a schematic view of the electrode member of FIG. 7 after being wound.

14 is a schematic diagram of a second embodiment of the electrode member according to the present invention.

15 is a cross-sectional view taken along line B-B of FIG. 14.

16 is a schematic diagram of the insulating substrate and the first conductive layer in FIG. 15.

17 is a schematic diagram of a third embodiment of an electrode member according to the present invention.

18 is a cross-sectional view taken along line C-C of FIG. 17.

19 is a schematic diagram of a fourth embodiment of the electrode member according to the present invention.

20 is a cross-sectional view taken along line D-D of FIG. 19.

21 is a schematic diagram of the first conductive layer of the electrode member of FIG. 19.

22 is a schematic diagram of a fifth embodiment of the electrode member according to the present invention.

Fig. 23 is a cross-sectional view taken along line E-E of Fig. 22.

24 is a schematic diagram of the first conductive layer of the electrode member of FIG. 22.

Among them, the reference signs are described as follows:

1 Electrode components 5 Shell

11 Insulating substrate 6 Top cover plate

12 First conductive layer 7 electrode terminals

121 Main part 8 adapters 8 adapters

122 protrusions 9 rollers 9 rollers

13 Active material layer G strip groove

14 Second conductive layer G1 first groove

141 Part I G2 Second Groove

142 Part Two G3 Third Groove

15 Protective layer G4 fourth groove

16 Conductive structure P Electrical Guidance Department

2 Cathode structure X width direction

3 Negative electrode member Y thickness direction

4 Diaphragm, Z height direction

detailed description

The technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. The following description of at least one exemplary embodiment is actually merely illustrative, and in no way serves as any limitation to the present application and its application or use. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without carrying out creative work fall within the scope of protection of this application.

In the description of this application, it should be understood that the use of "first", "second" and other words to define parts is only for the purpose of distinguishing the corresponding parts. Unless otherwise stated, the above words are not special Meaning, so it cannot be understood as a limitation on the scope of protection of this application.

The secondary battery of the present invention includes an electrode assembly. Referring to FIG. 6, the electrode assembly includes a positive electrode member 2, a negative electrode member 3 and a separator 4. The separator 4 is provided between the positive electrode member 2 and the negative electrode member 3. The positive electrode member 2, the separator 4, and the negative electrode member 3 are stacked and wound into a flat shape. The electrode assembly is the core component of the secondary battery to realize the charge and discharge function.

The secondary battery of the present invention may be a soft-pack battery, and the electrode assembly formed by winding the positive electrode member 2, the separator 4, and the negative electrode member 3 is directly encapsulated in a packaging bag. The packaging bag may be an aluminum plastic film.

Of course, the secondary battery of the present application may also be a hard-shell battery. Specifically, referring to FIG. 5, the secondary battery mainly includes an electrode assembly, a case 5, a top cover plate 6, an electrode terminal 7 and an adapter sheet 8.

The housing 5 may have a hexahedral shape or other shapes. A cavity is formed inside the case 5 to accommodate the electrode assembly and the electrolyte. The case 5 forms an opening at one end, and the electrode assembly can be placed into the receiving cavity of the case 5 through the opening. The housing 5 may be made of conductive metal materials such as aluminum or aluminum alloy, or may be made of insulating materials such as plastic.

The top cover plate 6 is provided in the casing 5 and covers the opening of the casing 5, so that the electrode assembly is enclosed in the casing 5. The electrode terminal 7 is provided on the top cover plate 6. The upper end of the electrode terminal 7 protrudes to the upper side of the top cover plate 6, and the lower end can pass through the top cover plate 6 and extend into the housing 5. The adapter piece 8 is provided in the housing 5 and fixed to the electrode terminal 7. Both the electrode terminal 7 and the adapter tab 8 are two, the positive electrode member 2 is electrically connected to one electrode terminal 7 via one adapter tab 8, and the negative electrode member 3 is electrically connected to the other electrode terminal 7 via another adapter tab 8. The adapter piece 8 is welded to the electrode terminal 7.

In the secondary battery, at least one of the positive electrode member 2 and the negative electrode member 3 adopts the electrode member 1 described later.

7 to 13 are schematic diagrams of the first embodiment of the electrode member 1 of the present invention. 7 and 8, the electrode member 1 of the first embodiment includes an insulating base 11, a first conductive layer 12 and an active material layer 13. The first conductive layer 12 is provided on both surfaces of the insulating base 11, and the active material layer 13 is provided on the side of the first conductive layer 12 away from the insulating base 11.

The material of the insulating substrate 11 may be a PET (polyethylene terephthalate) film or a PP (polypropylene) film.

The material of the first conductive layer 12 is selected from at least one of a metal conductive material and a carbon-based conductive material; the metal conductive material is preferably at least one of aluminum, copper, nickel, titanium, silver, nickel-copper alloy, aluminum zirconium alloy, The carbon-based conductive material is preferably at least one of graphite, acetylene black, graphene, and carbon nanotubes.

The first conductive layer 12 may be formed on the surface of the insulating substrate 11 by at least one of vapor deposition method and electroless plating. Among them, the vapor deposition method is preferably a physical vapor deposition method (Physical Vapor Deposition, PVD), such as a thermal evaporation method (Thermal Evaporation Deposition).

The active material layer 13 may also be provided on the surface of the first conductive layer 12 by coating. The active material (such as lithium manganate, lithium iron phosphate), binder, conductive agent and solvent can be made into a slurry, and then the slurry is coated on the outer surfaces of the two first conductive layers 12, after the slurry is cured The active material layer 13 is formed.

Referring to FIG. 9, the first conductive layer 12 is provided with a strip-shaped groove G that extends substantially along the height direction Z and is used to relieve the stress of the first conductive layer 12. The length of the strip groove G in the width direction X is 0.001 mm to 1 mm, and it is much smaller than the length of the strip groove G extending in the height direction Z. The bar-shaped groove G may be linear or curved, and as a whole, the bar-shaped groove G only needs to extend approximately along the height direction Z; that is to say, between the extending direction of the bar-shaped groove G and the height direction Z There may be a small included angle (for example, the included angle may be less than 10 °).

The thickness of the insulating base 11 may be 1 μm-20 μm, and the thickness of the first conductive layer 12 may be 0.1 μm-10 μm. Since the first conductive layer 12 is relatively thin, the burrs generated by the first conductive layer 12 during the cutting of the electrode member 1 are small, and it is difficult to puncture the separator 4 of more than ten microns, thereby avoiding a short circuit and improving safety performance. In addition, when the foreign material pierces the electrode member 1 of the secondary battery, since the thickness of the first conductive layer 12 is small, the burrs generated by the first conductive layer 12 at the location pierced by the foreign material are small, and it is difficult to pierce the separator 4 , So as to avoid short circuits and improve safety performance.

The first conductive layer 12 includes a body portion 121 and a protrusion 122 extending from the body portion 121, the body portion 121 is coated with an active material layer 13, and the protrusion 122 is not coated with the active material layer 13. The active material layer 13 may be directly coated on the surface of the main body 121. Of course, alternatively, other materials may be provided between the main body 121 and the active material layer 13.

The portion of the insulating base 11 corresponding to the protrusion 122 and the protrusion 122 form an electric guide portion P. The electric guide portions P may be plural and arranged at intervals in the width direction X. Referring to FIG. 13, after the electrode member 1 is wound and formed, the plurality of electrical guides P are stacked in the thickness direction Y.

The electrode member 1 further includes a protective layer 15 provided on the side of the protrusion 122 away from the insulating base 11 and connected to the active material layer 13.

The protective layer 15 includes an adhesive and an insulating material. The insulating material includes at least one of aluminum oxide and aluminum oxyhydroxide. The binder, the insulating material and the solvent are mixed together to prepare a slurry, which is coated on the surface of the protrusion 122 and forms the protective layer 15 after curing. The hardness of the protective layer 15 is greater than the hardness of the protrusion 122.

The electrode member 1 further includes a conductive structure 16 that is welded to a region of the protrusion 122 that is not covered by the protective layer 15. 7 and 8, the conductive structures 16 are fixed on both sides of each electrical guide P in the thickness direction Y. Referring to FIG. 13, after the electrode member 1 is wound and formed, all the conductive structures 16 are stacked and welded to the adapter sheet 8 at the same time. Referring to FIG. 5, the current in the electrode member 1 can be output to the outside via the adapter 8 and the electrode terminal 7.

The electrode member 1 of the first embodiment can be formed in the following steps:

(1) The first conductive layer 12 is formed on the surface of the insulating substrate 11 by vapor deposition or chemical plating, thereby preparing a composite tape; referring to FIG. 9, during the molding process, the first conductive layer 12 is reserved Strip groove G.

(2) Referring to FIG. 10, the active material layer 13 and the protective layer 15 are simultaneously coated on the surface of the first conductive layer 12.

(3) Roll the active material layer 13 to compact the active material layer 13 and increase the density.

(4) Referring to FIG. 12, after the rolling is completed, a metal foil material (for example, aluminum foil) is welded on the first conductive layer 12, and then a plurality of electrical guide portions P and a plurality of conductive materials are cut along the broken line in FIG. The structure 16 further obtains the electrode member 1 shown in FIG. 7.

In step (1), the first conductive layer 12 may be formed on the surface of the insulating substrate 11 by vapor deposition or chemical plating, so the connection force between the first conductive layer 12 and the insulating substrate 11 is small, under the action of external forces , It may cause the first conductive layer 12 to easily fall off the surface of the insulating base 11.

Since the elastic modulus of the insulating base 11 is smaller than that of the first conductive layer 12, the ductility of the insulating base 11 is higher than that of the first conductive layer 12. In the step (three), the insulating base 11 is stretched under pressure. Since the insulating base 11 has high ductility, the insulating base 11 exerts a force on the first conductive layer 12. In the prior art, the force on the first conductive layer 12 cannot be released, so when the first conductive layer 12 extends to a certain extent, the force on the first conductive layer 12 will be greater than the insulating base 11 and the first conductive layer The connecting force between 12 causes the insulating base 11 and the first conductive layer 12 to slide relative to each other, so that the first conductive layer 12 falls off from the surface of the insulating base 11 and affects the performance of the electrode member 1.

In this application, a strip-shaped groove G is formed on the first conductive layer 12, and the strip-shaped groove G can effectively release the force on the first conductive layer 12, reduce the stress concentration, and avoid the first conductive layer 12 The applied force is too large, which effectively reduces the risk of the first conductive layer 12 falling off from the surface of the insulating base 11 and guarantees the performance of the electrode member 1.

Specifically, FIG. 11 shows the state of the first conductive layer 12 after rolling, in which the broken line shows the state of the bar-shaped groove G before rolling. During the rolling process in step (3), the force on the first conductive layer 12 is gradually concentrated in the strip groove G; when the force on the first conductive layer 12 is too large, the first conductive layer 12 will Cracking along the strip groove G under the action of force, so as to release the stress in time, avoid the acting force on the first conductive layer 12 is greater than the connecting force between the insulating base 11 and the first conductive layer 12, reduce the insulating base 11 The probability of slipping relative to the first conductive layer 12 ensures the performance of the electrode member 1.

During the use of the secondary battery, the current generated by the active material layer 13 flows through the main body 121 to the protrusion 122, that is, on the first conductive layer 12, the current generally flows in the height direction Z, therefore, the first The overcurrent area of the conductive layer 12 depends on the area of the cross section of the first conductive layer 12 perpendicular to the height direction Z. In this application, the strip groove G generally extends in the height direction Z, and its length in the width direction X is very small, that is, the size of the strip groove G in the height direction Z is larger than that of the strip groove G in the width direction X size of. Therefore, when the first conductive layer 12 is cracked along the strip-shaped groove G during the rolling process, the strip-shaped groove G has little effect on the overcurrent area of the first conductive layer 12, thereby ensuring the The overcurrent capability meets the requirements.

In step (3), as the rolling progresses, the force on the first conductive layer 12 will gradually increase; referring to FIG. 11, when the electrode member 1 is rolled for a certain length in the width direction X, the first conductive layer 12 The applied force will drive the first conductive layer 12 to crack along the strip groove G, thereby releasing the stress in time. Since the first conductive layer 12 has a large length in the width direction X, preferably, there are a plurality of strip-shaped grooves G, and the plurality of strip-shaped grooves G are arranged at intervals in the width direction X. The plurality of strip-shaped grooves G can release stress in a stepwise manner during the rolling process, avoiding that the acting force on the first conductive layer 12 is greater than the connecting force between the insulating base 11 and the first conductive layer 12, reducing the insulating base The probability of slipping relative to the first conductive layer 12 ensures the performance of the electrode member 1.

8 and 9, the strip groove G penetrates the first conductive layer 12 in the thickness direction Y, that is, in the thickness direction Y, the depth of the strip groove G is equal to the thickness of the first conductive layer 12. At this time, the first conductive layer 12 is more likely to crack along the strip groove G during the rolling process, thereby releasing the stress in time.

In step (2), the active material layer 13 may be filled into the strip groove G, therefore, the current on the active material layer 13 may flow to the first conductive layer 12 through the peripheral wall of the strip groove G, thereby improving the The current collecting capability of a conductive layer 12. In step (3), even if the first conductive layer 12 is cracked along the strip-shaped groove G, the active material layer 13 will be filled to the cracked portion under the action of the roller pressure.

Since the modulus of elasticity of the insulating base 11 is small, in step (3), the insulating base 11 corresponding to the main body 121 will extend to the lower side of the protrusion 122, causing the insulating base 11 inside the protrusion 122 to swell Deformation, and the protrusion 122 is easily deformed by the force of the insulating base 11 to generate cracks. In the present application, the protective layer 15 has a high strength, and can provide support for the protrusion 122 during the rolling of the electrode member 1, limit the deformation of the protrusion 122, and reduce the probability of the protrusion 122 cracking To improve the overcurrent capability of the electrode member 1.

During the operation of the secondary battery, the protrusion 122 may come off due to vibration and other factors; therefore, the protective layer 15 is preferably connected to the active material layer 13 so that the protective layer 15 can be fixed to the active material layer 13 to increase the protective layer The bonding force of 15 on the electrode member 1 improves the seismic resistance and prevents the protective layer 15 from falling off together with the protrusion 122. At the same time, the protrusion 122 is most likely to bulge near the root of the active material layer 13 (that is, the boundary between the protrusion 122 and the main body 121), so when the protective layer 15 is connected to the active material layer 13, the protrusion can be reduced The deformation of the portion 122 reduces the probability of cracks, thereby improving the overcurrent capability of the electrode member 1.

The other four embodiments will be described below. In order to simplify the description, the following mainly introduces the differences between the other four embodiments and the first embodiment, and the undescribed parts can be understood with reference to the first embodiment.

14 to 16 are schematic diagrams of the second embodiment of the electrode member of the present invention. Referring to FIGS. 14 and 16, in the thickness direction Y, the depth of the strip groove G is smaller than the thickness of the first conductive layer 12. Compared to the first embodiment, the first conductive layer 12 of the second embodiment has a larger flow area. The cross section of the strip groove G may be U-shaped or V-shaped.

17 and 18 are schematic diagrams of the third embodiment of the electrode member of the present invention. Referring to FIGS. 17 and 18, compared with the first embodiment, the electrode member 1 of the third embodiment further includes a second conductive layer 14 having a first portion 141 located in the strip-shaped groove G. The first part 141 is filled into the strip groove G, and the current around the strip groove G can be transmitted through the first part 141; in other words, the first part 141 can repair the conductive network of the first conductive layer 12 and increase the overcurrent area To ensure the overcurrent capability of the electrode assembly 1 as a whole.

In the first embodiment, the active material layer 13 is filled into the strip groove G, therefore, the distribution of the active material layer 13 is not uniform, that is, the thickness of the active material layer 13 at the strip groove G is Thickness greater than other locations. During the operation of the secondary battery, the active material layer 13 may deposit lithium at a position corresponding to the strip groove G. In the third embodiment, the first portion 141 is filled in the strip-shaped groove G, thereby ensuring the flatness of the first conductive layer 12, improving the uniformity of the distribution of the active material layer 13, and reducing the risk of lithium deposition.

The second conductive layer 14 further includes a second portion 142 disposed on the surface of the first conductive layer 12 away from the insulating base 11 and connected to the first portion 141, and the active material layer 13 disposed on the second portion 142 away from the first The surface of the conductive layer 12.

The second conductive layer 14 may be a metallic material or a non-metallic material. In order to reduce the burrs generated when foreign objects pierce the electrode member 1, the second conductive layer 14 is preferably a non-metallic material that does not easily generate burrs. Specifically, the conductive carbon, the binder, and the solvent can be first made into a slurry, and then the slurry is coated on the first conductive layer 12, and the second conductive layer 14 is formed after the slurry is cured. During the coating process, the slurry is filled into the strip groove G and the first portion 141 is formed.

In step (2), the slurry of the second conductive layer 14 may be applied to the first conductive layer 12 first, and then the slurry of the active material layer 13 and the slurry of the protective layer 15 may be applied to the second The surface of the conductive layer 14.

In step (three), even if the first conductive layer 12 is cracked along the strip groove G, the second portion 142 will be filled to the cracked portion under the action of the roller pressure, so that even if the first conductive layer 12 is repaired The conductive network increases the overcurrent area to ensure the overall overcurrent capability of the electrode assembly 1.

If the second conductive layer 14 is only provided on the surface of the first conductive layer 12, the current of the second conductive layer 14 can only be conducted to the first conductive layer 12 through the surface of the first conductive layer 12. In the present application, the first portion 141 of the second conductive layer 14 is embedded in the strip-shaped groove G on the first conductive layer 12, therefore, not only can current be conducted to the first conductive layer 12 through the surface of the first conductive layer 12, but also Conduction can be conducted through the peripheral wall of the strip groove G, thereby increasing multiple conduction paths, forming a multi-point conductive network, improving the conductivity of the electrode member 1, reducing the polarization of the electrode member 1 and the secondary battery, and improving the secondary High rate charge and discharge performance of the battery.

The second portion 142 is at least partially located on the surface of the protrusion 122 away from the insulating base 11. The protective layer 15 may be disposed on the surface of the second portion 142 away from the protrusion 122. The conductive structure 16 is welded to the area of the protrusion 122 not covered by the second portion 142.

In the step (three), the main body portion 121 is extended by the insulating base 11, and the protrusion 122 is hardly extended. The main body 121 and the insulating base 11 apply a force to the protrusion 122 when they are extended, and because the protrusion 122 is thin, the protrusion 122 will generate micro cracks under the force. In this application, the second portion 142 is provided on the surface of the protrusion 122. Therefore, even if the protrusion 122 generates a crack during rolling, the current at the crack can be transmitted outward through the second portion 142, thereby achieving The repair of the conductive network ensures the overall overcurrent capability of the electrode member 1.

The rigidity of the second conductive layer 14 is less than the rigidity of the first conductive layer 12. That is to say, the second conductive layer 14 is more easily deformed when stressed. When the protrusion 122 deforms, the second portion 142 will also deform along with the protrusion 122; even if the protrusion 122 cracks due to excessive deformation, the second portion 142 is less likely to break, thereby ensuring the transmission of current.

The strip-shaped groove G penetrates the first conductive layer 12 in the thickness direction Y, and the first portion 141 of the second conductive layer 14 is connected to the insulating base 11. The first portion 141 is embedded in the strip-shaped groove G and adhered to the insulating base 11, thereby increasing the connection strength of the first conductive layer 12, the second conductive layer 14, and the insulating base 11.

19 to 21 are schematic diagrams of a fourth embodiment of the electrode member of the present invention. Referring to FIGS. 19 to 21, compared to the third embodiment, the bar-shaped groove G of the fourth embodiment includes a first groove G1 formed in the protrusion 122.

In step (3), the portion of the insulating base 11 corresponding to the main body 121 is stretched, and the portion of the insulating base 11 corresponding to the main body 121 exerts a force on the portion of the insulating base 11 corresponding to the protrusion 122. As a result, the portion of the insulating base 11 corresponding to the protrusion 122 is extended. The protrusion 122 is limited by the protective layer 15 and is therefore almost inextensible; the portion of the insulating base 11 corresponding to the protrusion 122 will exert a force on the protrusion 122 when it is expanded, if the force is greater than the insulation base 11 and the protrusion Due to the connection force of the portion 122, the protrusion 122 is easily detached from the insulating base 11. In this application, the first groove G1 can effectively release the force on the protrusion 122, reduce the stress concentration, avoid excessive force on the protrusion 122, effectively reduce the probability of the protrusion 122 falling off, and ensure The performance of the electrode member 1.

Preferably, the first groove G1 does not exceed the protective layer 15 in a direction away from the active material layer 13. The area covered by the protection layer 15 of the protrusion 122 is subjected to the greatest stress. Therefore, the first groove G1 only needs to be provided in the area covered by the protection layer 15 of the protrusion 122. The area of the protrusion 122 that is not covered by the protective layer 15 is less stressed, and there is no risk of falling off. If the first groove G1 extends to the area of the protrusion 122 that is not covered by the protective layer 15, it will decrease The overcurrent capability of the protrusion 122.

The bar-shaped groove G further includes a second groove G2 formed in the main body 121, and the first groove G1 communicates with the second groove G2.

In step (3), the main body 121 extends under the force applied by the insulating base 11. Since the protrusion 122 is restricted by the protective layer 15, the protrusion 122 is almost inextensible. Therefore, the area of the main body 121 near the protrusion 122 is subjected to the reaction force of the protrusion 122. In other words, the area of the main body 121 close to the protrusion 122 receives the force of the insulating base 11 and the protrusion 122 at the same time. Therefore, the area of the main body 121 close to the protrusion 122 is easily detached from the insulating base 11. In this application, the second groove G2 extends to the area of the main body 121 near the protrusion 122, thereby effectively releasing the force on the main body 121, reducing the stress concentration, and effectively reducing the insulating base 11 and the main body The probability of 121 relative slippage ensures the performance of the electrode member 1.

The strip-shaped groove G further includes a plurality of third grooves G3 arranged at intervals in the width direction X, and the third grooves G3 are formed in the body portion 121. In the width direction X, each third groove G3 is located between two adjacent second grooves G2; in the height direction Z, the third groove G3 and the second groove G2 are offset from each other.

22 to 24 are schematic diagrams of a fifth embodiment of the electrode member of the present invention. Referring to FIGS. 22 to 24, the bar-shaped groove G of the fifth embodiment includes a third groove G3 and a fourth groove G4 formed in the body portion 121. The third grooves G3 are plural and arranged at intervals in the width direction X, and the fourth grooves G4 are plural and arranged at intervals in the width direction X.

In the width direction X, each third groove G3 is located between two adjacent fourth grooves G4. In the height direction Z, the third groove G3 and the fourth groove G4 are offset from each other. The third groove G3 and the fourth groove G4 are dispersedly arranged in the width direction X and the height direction Z, which can improve the stress relief effect and improve the uniformity.

The present application also provides a method for manufacturing a secondary battery, which can improve the safety performance of the secondary battery. Secondary battery manufacturing methods include:

Provide a positive electrode member 2, a negative electrode member 3, and a separator 4, and wind the positive electrode member 2, the separator 4, and the negative electrode member 3 to form an electrode assembly; wherein, the positive electrode member 2 and the negative electrode At least one of the members 3 adopts the aforementioned electrode member 1;

A transition piece 8 is provided, and a plurality of conductive structures 16 of the electrode assembly are stacked and welded to the transition piece 8;

Provide a top cover plate 6 and an electrode terminal 7 fixed to the top cover plate 6, and weld the adapter sheet 8 to the electrode terminal 7;

A case 5 is provided, the electrode assembly is placed into the case 5, and then the top cover plate 6 is connected to the case 5.

In the electrode member 1 used in the manufactured secondary battery, the thickness of the first conductive layer 12 is small; when a foreign object pierces the electrode member 1 of the secondary battery, the first conductive layer 12 is generated at the location pierced by the foreign object The burr is small, it is difficult to puncture the diaphragm 4, thereby avoiding short circuit and improving safety performance. In addition, a strip groove G is formed on the first conductive layer 12, and the strip groove G can effectively release the force on the first conductive layer 12, reduce the stress concentration, and effectively reduce the first conductive layer 12 from The risk of the surface of the insulating substrate 11 falling off ensures the performance of the electrode member 1 and the secondary battery.

Claims

An electrode member (1) of a secondary battery, including an insulating substrate (11), a first conductive layer (12) and an active material layer (13);

The first conductive layer (12) is disposed on the surface of the insulating base (11), and the active material layer (13) is disposed on the first conductive layer (12) away from the insulating base (11) One side

The first conductive layer (12) is provided with a bar-shaped groove (G) extending in the height direction (Z).
The electrode member (1) according to claim 1, characterized in that the electrode member (1) further comprises a second conductive layer (14), the second conductive layer (14) having a concave shape located in the strip The first part (141) in the groove (G).
The electrode member (1) according to claim 2, wherein the second conductive layer (14) further includes a second portion (142), the second portion (142) is disposed on the first conductive The layer (12) is away from the surface of the insulating substrate (11) and connected to the first part (141), the active material layer (13) is disposed on the second part (142) away from the first conductive The surface of layer (12).
The electrode member (1) according to claim 3, characterized in that

The first conductive layer (12) includes a body portion (121) and a protrusion (122) extending from the body portion (121), the body portion (121) is coated with the active material layer (13) , The protrusion (122) is not coated with the active material layer (13);

The bar-shaped groove (G) includes a first groove (G1) formed in the protrusion (122), and the second portion (142) is at least partially located away from the protrusion (122) Describe the surface of the insulating substrate (11).
The electrode member (1) according to claim 4, wherein the strip-shaped groove (G) further includes a second groove (G2) formed in the body portion (121), the first The groove (G1) communicates with the second groove (G2).
The electrode member (1) according to claim 4, characterized in that the electrode member (1) further comprises a protective layer (15), the protective layer (15) is provided on the second part (142) The first groove (G1) does not exceed the protective layer (15) away from the surface of the protrusion (122) and connected to the active material layer (13).
The electrode member (1) according to claim 2, characterized in that the rigidity of the second conductive layer (14) is less than the rigidity of the first conductive layer (12).
The electrode member (1) according to claim 2, wherein the strip-shaped groove (G) penetrates the first conductive layer (12) in the thickness direction (Y), and the second conductive layer The first part (141) of (14) is connected to the insulating base (11).
The electrode member (1) according to claim 1, wherein there are a plurality of strip-shaped grooves (G), and the plurality of strip-shaped grooves (G) are arranged at intervals in the width direction (X) .
A secondary battery is characterized by comprising an electrode assembly, the electrode assembly comprising the electrode member (1) according to any one of claims 1-9.
A method for manufacturing a current collector, characterized in that it includes:

Provide an insulating substrate (11);

A conductive material is fixed to the surface of the insulating substrate (11) to form a first conductive layer (12), and the first conductive layer (12) is provided with a strip-shaped groove (G) extending in a height direction (Z) ).
The method for manufacturing a current collector according to claim 11, wherein the conductive material is fixed to the surface of the insulating substrate (11) by vapor deposition or electroless plating.
The method for manufacturing a current collector according to claim 11 or 12, further comprising:

Applying a conductive paste to a part of the surface of the first conductive layer (12), and filling the conductive paste into the strip-shaped groove (G);

After the conductive paste is cured, a second conductive layer (14) is formed.
An electrode member manufacturing method, characterized in that it includes:

Providing a current collector manufactured according to the manufacturing method according to claim 11 or 12;

Applying a slurry including an active material to a part of the surface of the first conductive layer (12), and filling the strip-shaped groove (G) with the slurry including the active material;

After the slurry including the active material is cured, an active material layer (13) is formed, and then the active material layer (13) is rolled;

Welding a metal foil to the area of the first conductive layer (12) not coated with the active material layer (13);

A part of the metal foil and a part of the current collector are cut away to form a plurality of spaced-apart conductive structures (16) and a plurality of spaced-apart electrical guides (P).
The method of manufacturing an electrode member according to claim 14, wherein

The manufacturing method further includes: applying a slurry including an insulating material to a part of the surface of the first conductive layer (12), and forming a protective layer (15) after the slurry including the insulating material is cured;

The protective layer (15) is formed before welding the metal foil.
A method for manufacturing a secondary battery, characterized in that it includes:

A positive electrode member (2), a negative electrode member (3) and a separator (4) are provided, and the positive electrode member (2), the separator (4) and the negative electrode member (3) are wound into one body to form an electrode assembly , Wherein at least one of the positive electrode member (2) and the negative electrode member (3) is manufactured according to the manufacturing method of the electrode member of claim 14 or 15;

Providing a transition piece (8), laminating and welding a plurality of conductive structures (16) of the electrode assembly to the transition piece (8);

Providing a top cover plate (6) and an electrode terminal (7) fixed to the top cover plate (6), and welding the adapter piece (8) to the electrode terminal (7);

A case (5) is provided, the electrode assembly is placed inside the case (5), and then the top cover plate (6) is connected to the case (5).
An electrode member manufacturing method, characterized in that it includes:

Providing a current collector manufactured according to the manufacturing method of claim 13;

Applying a slurry including an active material to a part of the surface of the second conductive layer (14);

Curing the slurry including the active material and forming an active material layer (13), and then rolling the active material layer (13);

Welding a metal foil to the area of the first conductive layer (12) that is not coated with the second conductive layer (14);

A part of the metal foil and a part of the current collector are cut away to form a plurality of spaced-apart conductive structures (16) and a plurality of spaced-apart electrical guides (P).
The method of manufacturing an electrode member according to claim 17, wherein

The manufacturing method further includes: applying a slurry including an insulating material to a partial area of the surface of the second conductive layer (14), and then curing the slurry including the insulating material and forming a protective layer (15);

The protective layer (15) is formed before welding the metal foil.
A method for manufacturing a secondary battery, characterized in that it includes:

A positive electrode member (2), a negative electrode member (3) and a separator (4) are provided, and the positive electrode member (2), the separator (4) and the negative electrode member (3) are wound into one body to form an electrode assembly , Wherein at least one of the positive electrode member (2) and the negative electrode member (3) is manufactured according to the method for manufacturing an electrode member according to claim 17 or 18;

Providing a transition piece (8), laminating and welding a plurality of conductive structures (16) of the electrode assembly to the transition piece (8);

Providing a top cover plate (6) and an electrode terminal (7) fixed to the top cover plate (6), and welding the adapter piece (8) to the electrode terminal (7);

A case (5) is provided, the electrode assembly is placed inside the case (5), and then the top cover plate (6) is connected to the case (5).