WO2023142430A1

WO2023142430A1 - Composite current collector, method for preparing composite current collector, electrode plate, battery, and electric device

Info

Publication number: WO2023142430A1
Application number: PCT/CN2022/111697
Authority: WO
Inventors: 周龙; 庞文杰
Original assignee: 厦门海辰储能科技股份有限公司
Priority date: 2022-01-28
Filing date: 2022-08-11
Publication date: 2023-08-03

Abstract

A composite current collector (1000), a method for preparing a composite current collector, an electrode plate, a battery and an electric device. The composite current collector (1000) comprises a support layer (100) and a conductive layer (200), wherein the conductive layer (200) is formed on the surface of the support layer (100); and the surface of the conductive layer (200) is provided with holes (20), the hole (20) having a diameter of 10 μm to 500 μm.

Description

Composite current collector, method for preparing composite current collector, pole piece, battery and electrical equipment

priority information

This application claims the priority and rights of patent applications with patent application numbers 202210105169.8 and 202220235986.0 filed with the State Intellectual Property Office of China on January 28, 2022, and the entirety of which is hereby incorporated by reference.

technical field

The application belongs to the field of batteries, and in particular relates to a composite current collector, a method for preparing a composite current collector, a pole piece, a battery and electrical equipment.

Background technique

Usually, through holes are formed on the current collector to reduce the weight of the pole piece. However, too large through holes will cause the coating slurry to leak during the cell manufacturing process, which is not conducive to the formation of a uniform active material coating. Leakage of the cloth slurry will form pits on the surface of the pole piece. The pits will cause irregular lithium intercalation in the negative electrode of the battery during charging and discharging, and generate lithium dendrites. The lithium dendrites will pierce the separator and cause an internal short circuit in the battery. , causing the thermal runaway of the battery to cause a combustion explosion.

Therefore, the existing current collectors need to be improved.

Contents of the invention

This application aims to solve one of the technical problems in the related art at least to a certain extent. For this reason, an object of the present application is to propose a composite current collector, a method for preparing a composite current collector, a pole piece, a battery, and an electrical equipment. It is heavy, and the conductivity of the composite current collector does not deteriorate. On the other hand, it avoids the formation of pits caused by the leakage of the coated active slurry during the cell manufacturing process, so that the lithium branches will not appear during the charging and discharging process of the battery. The crystal pierces the diaphragm and causes the thermal runaway of the battery to cause combustion and explosion problems, which improves the safety performance and service life of the battery, and can also ensure that the battery has high electrical performance.

In one aspect of the present application, the present application proposes a composite current collector. According to an embodiment of the present application, the composite current collector includes:

support layer;

A conductive layer, the conductive layer is formed on the surface of the supporting layer, and holes are formed on the surface of the conductive layer, and the diameter of the holes is 10 μm to 500 μm.

According to the composite current collector of the embodiment of the present application, by forming holes with a diameter of 10 μm to 500 μm on the conductive layer of the composite current collector, on the one hand, the cost and weight of the battery pole piece can be reduced, and the conductivity of the composite current collector is not high. On the other hand, it avoids the formation of pits caused by the leakage of the coating active slurry during the battery manufacturing process, so that the formation of lithium dendrites during the charging and discharging process of the battery will not occur, which will pierce the separator and cause the thermal runaway of the battery. The problem of burning and explosion is caused, that is, the safety performance and service life of the battery are improved, and the battery can also be guaranteed to have high electrical performance.

In addition, the composite current collector according to the above-mentioned embodiments of the present application may also have the following additional technical features:

In some embodiments of the present application, the thickness of the conductive layer is 0.1 μm˜1.5 μm.

In some embodiments of the present application, the diameter of the hole is 50 μm˜20 μm. As a result, the safety performance and service life of the battery are improved while reducing the cost and weight of the battery.

In some embodiments of the present application, the center-to-center distance between adjacent holes is 30 μm˜5000 μm.

In some embodiments of the present application, the depth of the hole is 0.01 μm˜1.5 μm, and the depth of the hole is not greater than the thickness of the conductive layer. As a result, the safety performance and service life of the battery are improved while reducing the cost and weight of the battery.

In some embodiments of the present application, the hole is a blind hole, and the distance between the bottom of the blind hole and the support layer is 0.01 μm˜1 μm.

In some embodiments of the present application, the conductive layer includes a first conductive layer and a second conductive layer, the first conductive layer is formed on the upper surface of the support layer, and the second conductive layer is formed on the The lower surface of the support layer, and the holes are formed on both the first conductive layer and the second conductive layer. As a result, the safety performance and service life of the battery are improved while reducing the cost and weight of the battery.

In some embodiments of the present application, the hole on the first conductive layer is arranged opposite to the hole on the second conductive layer. As a result, the safety performance and service life of the battery are improved while reducing the cost and weight of the battery.

In some embodiments of the present application, the holes on the first conductive layer and the holes on the second conductive layer are arranged in a staggered manner. As a result, the safety performance and service life of the battery are improved while reducing the cost and weight of the battery.

In some embodiments of the present application, the conductive layer includes a main body region and a tab region, and the distribution density of the holes on the conductive layer in a region away from the tab region is greater than that in a region close to the tab region. The distribution density of the holes on the area. In this way, the problem of severe heat release in the tab region can be reduced.

In some embodiments of the present application, the holes on the first conductive layer and/or the second conductive layer are uniformly distributed.

In some embodiments of the present application, multiple holes are formed on both the first conductive layer and the second conductive layer;

A plurality of the holes on the first conductive layer are arranged in an array; and/or

The plurality of holes on the second conductive layer are arranged in an array.

In some embodiments of the present application, the adjacent holes on the first conductive layer are arranged in a staggered manner; and/or the adjacent holes on the second conductive layer are arranged in a staggered manner.

In some embodiments of the present application, a plurality of holes are formed on the surface of the conductive layer, and at least a part of the holes have the same shape.

In some embodiments of the present application, the holes are circular holes or polygonal holes.

In yet another aspect of the present application, the present application proposes a method for preparing the above-mentioned composite current collector. According to an embodiment of the present application, the method includes:

forming a conductive layer on the support layer;

A part of the conductive layer is vaporized by laser spot burning, so as to form holes in the conductive layer.

According to the method for preparing the above-mentioned composite current collector according to the embodiment of the present application, a conductive layer is first formed on the support layer, and then the conductive layer is gasified by laser spot burning, thereby forming holes on the conductive layer, that is, the prepared The above-mentioned composite current collector with holes, on the one hand, the composite current collector with this structure can reduce the cost and weight of the battery pole piece, and the conductivity of the obtained composite current collector does not deteriorate, and on the other hand, it avoids the The leakage of the coated active slurry leads to the formation of pits, so that the formation of lithium dendrites during the charging and discharging process of the battery will not occur and the problem of piercing the separator will cause the thermal runaway of the battery and cause combustion and explosion, which improves the safety of the battery performance and service life, and can also ensure that the battery has high electrical performance.

forming a plurality of protrusions on the support layer;

Using magnetron sputtering to form a conductive layer on the support layer, the conductive layer surrounds and covers the plurality of protrusions;

Pickling the conductive layer to remove the plurality of protrusions and the conductive layer covering the surfaces of the plurality of protrusions, thereby forming holes on the conductive layer.

According to the method for preparing the above-mentioned composite current collector according to the embodiment of the present application, a plurality of protrusions are first formed on the support layer, and then a conductive layer is formed on the support layer by magnetron sputtering. Since the copper layer with a plurality of protrusion regions The adhesion is poor. After pickling, the copper layer with multiple raised areas is dissolved in the acid solution, thereby forming holes on the conductive layer, that is, the above-mentioned composite current collector with holes is prepared. The composite current collector with this structure On the one hand, it can reduce the cost and weight of the battery pole piece, and the conductivity of the obtained composite current collector does not deteriorate. On the other hand, it avoids the formation of pits caused by the leakage of the coating active slurry during the cell manufacturing process, thereby There will be no problem of lithium dendrites forming in the charging and discharging process of the battery and piercing the separator to cause thermal runaway of the battery and cause combustion and explosion problems, which improves the safety performance and service life of the battery, and can also ensure that the battery has a higher battery life. performance.

In the fourth aspect of the application, the application proposes a pole piece. According to an embodiment of the present application, the pole piece includes:

Composite current collector;

an active material layer formed on the conductive layer of the composite current collector and embedded in the pores,

Wherein, the composite current collector is the above composite current collector or the composite current collector obtained by the above method.

According to the pole piece of the embodiment of the present application, by using the above-mentioned composite current collector with holes, on the one hand, the cost and weight of the battery pole piece can be reduced, and the conductivity of the pole piece does not deteriorate, and on the other hand, the battery manufacturing process is avoided. During the coating process, the active slurry leaks and causes the formation of pits, so that there will be no problem that lithium dendrites will be formed during the charging and discharging process of the battery, which will pierce the separator and cause the thermal runaway of the battery to cause combustion and explosion. The safety performance and service life of the battery can also ensure that the battery has high electrical performance.

In a fifth aspect of the present application, the present application provides a battery. According to an embodiment of the present application, the positive electrode and/or negative electrode of the battery adopts the above-mentioned pole piece. As a result, the safety performance and service life of the battery are improved while the cost and weight of the battery are reduced, and the battery has excellent electrical performance.

In a sixth aspect of the present application, the present application provides an electric device. According to an embodiment of the present application, the electric device includes the above-mentioned battery. As a result, the safety performance and service life of the battery are improved while the cost and weight of the battery are reduced, and the battery has excellent electrical performance.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of drawings

The above and/or additional aspects and advantages of the present application will become apparent and understandable from the description of the embodiments in conjunction with the following drawings, wherein:

1 is a cross-sectional view of a composite current collector according to one embodiment of the present application;

2 is a cross-sectional view of a composite current collector according to yet another embodiment of the present application;

3 is a cross-sectional view of a composite current collector according to yet another embodiment of the present application;

4 is a cross-sectional view of a composite current collector according to yet another embodiment of the present application;

5 is a top view of a composite current collector according to one embodiment of the present application;

6 is a top view of a composite current collector according to another embodiment of the present application;

7 is a top view of a composite current collector according to yet another embodiment of the present application;

8 is a schematic flow diagram of a method for preparing a composite current collector according to an embodiment of the present application;

9 is a schematic flow diagram of a method for preparing a composite current collector according to another embodiment of the present application;

Fig. 10 is a cross-sectional view of a pole piece according to an embodiment of the present application,

Reference signs:

Composite current collector: 1000; supporting layer: 100; conductive layer: 200; hole 20; first conductive layer: 21; second conductive layer: 22;

Detailed ways

Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary, and are intended to explain the present application, and should not be construed as limiting the present application.

In one aspect of the present application, the present application proposes a composite current collector. According to an embodiment of the present application, referring to FIG. 1, the composite current collector 1000 includes a support layer 100 and a conductive layer 200, wherein the conductive layer 200 is formed on the surface of the support layer 100, and at least a part of the surface of the conductive layer 200 is formed There are holes 20, and the diameter of the holes 20 is 10 μm to 500 μm, preferably 50 μm to 200 μm.

The applicant found that by forming holes 20 on the conductive layer 200 of the composite current collector 1000, on the one hand, the cost and weight of the battery pole piece can be reduced, and the conductivity of the composite current collector 1000 does not deteriorate, and on the other hand, the electrical During the core manufacturing process, the coating active slurry leaks and causes the formation of pits, so that there will be no problem that lithium dendrites will be formed during the charging and discharging process of the battery, which will pierce the separator and cause the thermal runaway of the battery to cause combustion and explosion. The safety performance and service life of the battery are improved, and the applicant has also found that if the diameter of the hole 20 is too large, the active material coated thereon will easily produce surface polarization and lead to lithium precipitation, and if the diameter of the hole 20 is too small, The weight reduction effect on the composite current collector 1000 is not obvious, and the slurry is not easy to fill the holes when the active material is coated. Therefore, by limiting the diameter of the pores to 10 μm to 500 μm in the present application, the safety performance and service life of the battery can be improved while reducing the cost and weight of the composite current collector 1000 .

According to an embodiment of the present application, the support layer 100 is an insulating material, and those skilled in the art can select its specific material according to actual needs. For example, the support layer 100 includes but is not limited to polyphenylene sulfide, polypropylene, polyimide or polyethylene terephthalate.

According to another embodiment of the present application, the thickness of the conductive layer 200 is 0.1 μm-1.5 μm, and the depth of the hole 20 on the conductive layer 200 is 0.01 μm-1.5 μm, wherein the depth of the hole 20 is not greater than the thickness of the conductive layer 200 , that is, the hole 20 penetrates the conductive layer 200 ( FIG. 1 ) or does not penetrate the conductive layer 200 ( FIG. 2 ), and the supporting layer 100 is intact without holes. According to a specific embodiment of the present application, referring to FIG. 2 , the hole 20 is a blind hole, and the distance between the bottom of the blind hole and the support layer 100 is 0.01 μm to 1 μm, that is, the blind hole does not penetrate the conductive layer 200, that is, the hole Part of the conductive layer 200 remains at the bottom. The applicant found that by keeping part of the conductive layer 200 at the bottom of the blind hole, the polarization phenomenon on the surface of the battery pole piece can be prevented. Further, the conductive layer 200 is provided with a plurality of holes 20 , and the center-to-center distance between adjacent holes 20 is 30 μm˜5000 μm, preferably 300˜1500 μm. The applicant found that if the center-to-center distance of adjacent holes 20 is too large, the effect of reducing the cost and weight of the composite current collector 1000 is not obvious, and if the center-to-center distance of adjacent holes 20 is too small, it will affect the composite current collector 1000 along its The conductivity in the plane direction affects the charge and discharge rate of the battery. Therefore, in the present application, by setting the center-to-center distance of adjacent holes to be 30 μm to 5000 μm, the charge and discharge rate of the battery can be improved while reducing the cost and weight of the composite current collector 1000 .

According to another embodiment of the present application, the conductive layer 200 includes a first conductive layer 21 and a second conductive layer 22, the first conductive layer 21 is formed on the upper surface of the support layer 100, and the second conductive layer 22 is formed on the support layer 100 , and holes 20 are formed on the first conductive layer 21 and the second conductive layer 22 .

Those skilled in the art can select the arrangement of the holes 20 on the first conductive layer 21 and the second conductive layer 22 according to actual needs. For example, referring to FIG. 3 , the holes 20 on the first conductive layer 21 and the second conductive layer 22 The holes 20 on the first conductive layer 21 and the holes 20 on the second conductive layer 22 are arranged in a staggered manner as shown in FIG. 4 . It should be noted that those skilled in the art can also combine the arrangements of the holes 20 on the first conductive layer 21 and the second conductive layer 22 in FIG. 3 and FIG. A part of the holes 20 on the second conductive layer 22 are arranged opposite to each other, and another part of the holes 20 on the first conductive layer 21 and another part of the holes 20 on the second conductive layer 22 are arranged in a staggered manner.

For another example, please refer to FIG. 6 , a plurality of holes 20 are formed on the first conductive layer 21 and the second conductive layer 22; the plurality of holes 20 on the first conductive layer 21 are arranged in an array, and the plurality of holes on the second conductive layer 22 The holes 20 are arranged in an array. The array arrangement can be arranged in the form of an m*n array, and m and n can be equal or unequal.

According to yet another embodiment of the present application, a plurality of holes 20 are formed on at least a part of the surface of the conductive layer 200, at least some of the holes 20 have the same shape, for example, all the holes 20 on the conductive layer 200 have the same shape, and then For example, several holes 20 have the same shape, and several holes 20 have different shapes. Those skilled in the art can determine the shape of the hole 20 according to actual needs, process requirements and the like.

According to yet another embodiment of the present application, the hole 20 is a circular hole 20 or a polygonal hole 20 . Specifically, in the embodiments shown in FIGS. 5 to 7 , the holes 20 are all circular holes 20 . In other embodiments, the hole 20 may be a polygonal hole 20, for example, a triangular hole 20, a quadrilateral hole 20, a pentagonal hole 20, and the like. In other embodiments, the holes 20 may also be holes 20 with irregular shapes.

Further, referring to FIG. 5 , those skilled in the art can also select the arrangement of the holes 20 on the conductive layer 200 according to actual needs. Specifically, the conductive layer 200 includes a tab area 23 and a main body area 24. The tab area 23 is connected to one side of the body region 24, the holes 20 are arranged in the body region 24, and the distribution density of the holes 20 on the region away from the tab region 23 on the conductive layer 200 is greater than the distribution density of the holes 20 on the region close to the tab region 23 Density, for example, in FIG. 5 , the distribution density of the holes 20 on the region away from the tab region 23 on the first conductive layer 21 and/or the second conductive layer 22 is greater than that of the holes 20 on the region near the tab region 23 distribution density. The applicant found that the conductive area near the tab region 23 becomes smaller, which increases the current density and causes serious heat release. However, the present application sets the distribution density of the holes 20 in the region of the conductive layer 200 away from the tab region 23 The distribution density of the holes 20 in the region close to the tab region 23 can reduce the serious problem of heat release in the tab region 23 . Preferably, the distribution density of the holes 20 on the region away from the tab area 23 on the first conductive layer 21 is greater than the distribution density of the holes 20 on the area close to the tab area 23, and the distribution density of the holes 20 on the second conductive layer 22 away from the tab area 23 The distribution density of the holes 20 in the region is greater than the distribution density of the holes 20 in the region close to the tab region 23 . And those skilled in the art can select the distribution density difference of holes 20 on the first conductive layer 21 and/or the second conductive layer 22 on the region away from the tab region 23 and the region close to the tab region 23 according to actual needs. Referring to Fig. 6 again for example, the holes 20 on the first conductive layer 21 and/or the second conductive layer 22 are evenly distributed; The holes 20 in adjacent columns on the conductive layer 22 are arranged in a staggered manner. It should be noted that those skilled in the art can combine the arrangements of the holes on the first conductive layer 21 and the second conductive layer 22 in FIG. 6 and FIG. 7 according to actual needs.

It should be noted that those skilled in the art can select the material of the conductive layer 200 according to actual needs. For example, the conductive layer 200 includes but is not limited to a copper layer or an aluminum layer.

In the second aspect of the present application, the present application also proposes a method for preparing the above-mentioned composite current collector 1000 . According to an embodiment of the present application, referring to FIG. 8, the method includes:

A conductive layer is formed on the support layer.

In this step, those skilled in the art can select an applicable method to form a conductive layer on the support layer according to actual needs, for example, a magnetron sputtering method can be used to form a conductive layer on the upper and lower surfaces of the support layer, and those skilled in the art can according to In fact, it is necessary to select relevant operating parameters during the magnetron sputtering operation, as long as the thickness of the above-mentioned conductive layer can be satisfied, and the materials of the support layer and the conductive layer are the same as those described above, and will not be repeated here.

A part of the conductive layer is vaporized by laser spot burning to form holes in the conductive layer.

In this step, a part of the conductive layer is vaporized by means of laser point burning. Since the support layer does not absorb infrared laser light, the support layer remains intact, thereby forming holes on a part of the conductive layer, and those skilled in the art can The specific operating parameters of the laser spot burning process can be selected according to actual needs, as long as the above-described arrangement or arrangement, depth and diameter of the holes on the conductive layer can be obtained.

According to an embodiment of the present application, the conductive layer can be formed in two steps. First, a part of the conductive layer is formed on the support layer by magnetron sputtering, and then a part of the conductive layer is vaporized by laser spot burning. A hole is formed on a part of the conductive layer. Finally, the sample after laser drilling is continued to thicken the conductive layer by water electroplating, that is, the thickness of the conductive layer reaches the target thickness. Remove, so the point will not be thickened during the water plating process, i.e. the conductive layer will not be covered at the hole formed. It should be noted that those skilled in the art can select the specific operation of the water electroplating process according to actual needs, which will not be repeated here.

According to the method for preparing the above-mentioned composite current collector according to the embodiment of the present application, the above-mentioned composite current collector with holes can be prepared. On the one hand, the composite current collector with this structure can reduce the cost and weight of the battery pole piece, and the composite current collector The conductivity of the fluid does not deteriorate, and on the other hand, it avoids the formation of pits caused by the leakage of the coating active slurry during the cell manufacturing process, so that the formation of lithium dendrites and piercing the separator during the charging and discharging process of the battery will not occur. The problem of burning and explosion caused by the thermal runaway of the battery improves the safety performance and service life of the battery, and also ensures that the battery has high electrical performance.

It should be noted that the features and advantages described above for the composite current collector are also applicable to the method for preparing the composite current collector, and will not be repeated here.

In the third aspect of the present application, the present application also proposes another method for preparing the above-mentioned composite current collector 1000 . According to an embodiment of the present application, referring to FIG. 9, the method includes:

A plurality of protrusions are formed on the support layer.

In this step, a plurality of protrusions are formed on the surface of the support layer, and the protrusions can be formed by coating point-shaped oil droplets, and those skilled in the art can select the size and specific composition of the protrusions according to actual needs, as long as It only needs to satisfy the hole size, arrangement and arrangement described above, and details will not be repeated here.

Using magnetron sputtering to form a conductive layer on the support layer in step Sa, the conductive layer surrounds and covers the plurality of protrusions.

In this step, magnetron sputtering is used to form a conductive layer on the support layer in step Sa. Due to the poor adhesion of the conductive layer with multiple raised areas, the conductive layer with multiple raised areas will dissolve after pickling. In the acid solution, holes are formed in the conductive layer.

Due to the poor adhesion of the conductive layer with multiple raised areas, the conductive layer with multiple raised areas will be dissolved in the acid solution after pickling in this step, thereby forming holes on the conductive layer.

It should be noted that those skilled in the art can select the magnetron sputtering and the pH of the acid solution according to actual needs, as long as the arrangement or arrangement, depth and diameter of the holes on the conductive layer described above can be obtained. Yes, no more details here.

According to an embodiment of the present application, the conductive layer of this method can be formed in three steps. First, a plurality of protrusions are coated on the surface of the support layer, and then a part-thick conductive layer is formed on the support layer by magnetron sputtering. After pickling, the conductive layer in multiple raised areas will be dissolved in the acid solution, thereby forming holes on the conductive layer. Finally, the sample after pickling will continue to thicken the conductive layer by water electroplating, that is, the thickness of the conductive layer will reach target thickness. It should be noted that those skilled in the art can select the specific operation of the water electroplating process according to actual needs, which will not be repeated here.

In the fourth aspect of the application, the application proposes a pole piece. According to an embodiment of the present application, referring to FIG. 10 , the pole piece includes: a composite current collector 1000 and an active material layer 2000, wherein the composite current collector is the above-mentioned composite current collector 1000 or the composite current collector 1000 obtained by the above method, and the active material Layer 2000 is formed on conductive layer 200 of composite current collector 1000 and embedded in pores 20 .

Those skilled in the art can select the composition of the active material layer 2000 according to the actual application of the pole piece. For example, when the pole piece is used as a positive electrode, the conductive layer 200 in the composite current collector 1000 is an aluminum layer, and the active material layer 2000 includes iron phosphate. Lithium, conductive carbon black and polyacrylic acid; when the pole piece is used as a negative electrode, the conductive layer 200 in the composite current collector 1000 is a copper layer, and the active material layer 2000 includes graphite, styrene-butadiene rubber and sodium carboxymethyl cellulose.

The applicant found that by using the above-mentioned composite current collector 1000 with holes 20, on the one hand, the cost and weight of the battery pole piece can be reduced, and the conductivity of the pole piece does not deteriorate; Leakage of cloth active slurry leads to the formation of pits, so that there will be no problem of lithium dendrites formed during charging and discharging of the battery and piercing the separator, causing thermal runaway of the battery and causing combustion and explosion, which improves the safety performance of the battery And service life, in addition, it can also ensure that the battery has high electrical performance.

It should be noted that the features and advantages described above for the composite current collector and its preparation method are also applicable to the pole piece, and will not be repeated here.

In a fifth aspect of the present application, the present application provides a battery. According to an embodiment of the present application, the positive electrode and/or negative electrode of the battery adopts the above-mentioned pole piece. As a result, the safety performance and service life of the battery are improved while the cost and weight of the battery are reduced, and the battery has excellent electrical performance. It should be noted that the features and advantages described above for the pole piece are also applicable to the battery, and will not be repeated here.

In a sixth aspect of the present application, the present application provides an electric device. According to an embodiment of the present application, the electric device includes the above-mentioned battery. As a result, the safety performance and service life of the battery are improved while the cost and weight of the battery are reduced, and the battery has excellent electrical performance. It should be noted that the features and advantages described above for the battery are also applicable to the electric device, and will not be repeated here.

Specifically, electrical equipment includes, but is not limited to, energy storage equipment and power batteries. The energy storage device can be an energy storage container or a household energy storage cabinet. Power batteries can be applied to vehicles, including but not limited to pure electric vehicles, hybrid vehicles, and extended-range electric vehicles.

The present application will be described below with reference to specific embodiments. It should be noted that these embodiments are only illustrative and do not limit the present application in any way.

Example 1

Lithium batteries include:

Positive electrode: including a composite current collector and a positive electrode active material layer (the positive electrode slurry forming the positive electrode active material layer includes lithium iron phosphate, PVDF, conductive carbon black and NMP), the positive electrode active material layer is formed on the surface of the composite current collector, and the composite collector The fluid includes a polyphenylene sulfide support layer and an aluminum layer. The aluminum layer is formed on the upper and lower surfaces of the polyphenylene sulfide support layer. The parameters in the composite current collector are shown in Table 1. The holes on the first conductive layer and the second conductive layer are The holes are oppositely arranged, and the holes on the first conductive layer and the second conductive layer are uniformly distributed;

Negative electrode: including negative electrode current collector copper foil and negative electrode active material layer (the negative electrode slurry forming the negative electrode active material layer includes graphite, conductive agent SP, CMC, binder PVDF and SBR);

Diaphragm: pp film;

Electrolyte: a mixture of lithium hexafluorophosphate, ethylene carbonate, dimethyl carbonate and cyclic ethyl methyl carbonate.

Example 2

For the parameters of the composite current collector that constitutes the positive electrode in the lithium battery, refer to Table 1. The holes on the first conductive layer and the holes on the second conductive layer are staggered, and the holes on the first conductive layer and the second conductive layer are evenly distributed. Others are the same as Example 1.

Example 3

For the parameters of the composite current collector that constitutes the positive electrode in the lithium battery, refer to Table 1. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, and the adjacent holes on the first conductive layer are arranged in a staggered manner, and the holes on the second conductive layer are arranged oppositely. Adjacent holes are arranged in a staggered manner, and the others are the same as in Embodiment 1.

Example 4

For the parameters of the composite current collector that constitutes the positive electrode in the lithium battery, refer to Table 1. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, the holes on the first conductive layer are evenly distributed, and the adjacent holes on the second conductive layer Staggered arrangement, others are the same as embodiment 1.

Example 5

For the parameters of the composite current collector that constitutes the positive electrode in the lithium battery, refer to Table 1. The holes on the first conductive layer and the holes on the second conductive layer are staggered, the adjacent holes on the first conductive layer are staggered, and the holes on the second conductive layer are staggered. Evenly distributed, others are the same as in Example 1.

Example 6

For the parameters of the composite current collector that constitutes the positive electrode in the lithium battery, refer to Table 1. The holes on the first conductive layer and the holes on the second conductive layer are arranged staggered, and the adjacent holes on the first conductive layer are arranged staggered, and the holes on the second conductive layer are arranged staggered. Adjacent holes are arranged in a staggered manner, and the others are the same as in Embodiment 1.

Example 7

For the parameters of the composite current collector that constitutes the positive electrode in the lithium battery, refer to Table 1. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, and the distribution density of the holes on the first conductive layer away from the tab area is greater than that near the tab area. The distribution density of the holes on the area of the tab area, the distribution density of the holes on the area away from the tab area on the second conductive layer is greater than the distribution density of the holes on the area close to the tab area, and the others are the same as in Example 1.

Example 8

For the parameters of the composite current collector that constitutes the positive electrode in the lithium battery, refer to Table 1. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, the holes on the first conductive layer are evenly distributed, and the holes on the second conductive layer that are far away from the tab area The distribution density of the holes in the region is greater than that in the region near the tab region, and the others are the same as in Embodiment 1.

Example 9

For the parameters of the composite current collector that constitutes the positive electrode in the lithium battery, refer to Table 1. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, the holes on the second conductive layer are evenly distributed, and the holes on the first conductive layer away from the tab area The distribution density of the holes in the region is greater than that in the region near the tab region, and the others are the same as in Embodiment 1.

Example 10

Comparative example 1

There are no holes on the first conductive layer and the second conductive layer of the composite current collector that constitutes the positive electrode in the lithium battery, and the others are the same as in Example 1.

Each parameter of the composite current collector in Table 1 Embodiment 1-10

Evaluate the weight loss of the positive electrode collector obtained in Examples 1-10 and Comparative Example 1. Compared with the positive electrode collector of Comparative Example 1, the positive electrode collector obtained in Example 1-10 has obvious weight loss, and implement The lithium batteries obtained in Examples 1-10 have excellent cycle performance.

The resistivity of the positive current collector obtained in Examples 1-10 and Comparative Example 1 was evaluated, and the characterization results are shown in Table 2.

Table 2 The resistivity characterization results of the positive electrode current collector obtained in Examples 1-10 and Comparative Example 1

the	正极集流体电阻率/Ω·mPositive current collector resistivity/Ω m
实施例1Example 1	3.810 ^-8 3.810 ^-8
实施例2Example 2	3.710 ^-8 3.710 ^-8
实施例3Example 3	3.610 ^-8 3.610 ^-8
实施例4Example 4	3.710 ^-8 3.710 ^-8
实施例5Example 5	3.810 ^-8 3.810 ^-8
实施例6Example 6	3.810 ^-8 3.810 ^-8
实施例7Example 7	3.710 ^-8 3.710 ^-8
实施例8Example 8	3.910 ^-8 3.910 ^-8
实施例9Example 9	3.710 ^-8 3.710 ^-8
实施例10Example 10	3.710 ^-8 3.710 ^-8
对比例1Comparative example 1	3.910 ^-8 3.910 ^-8

It can be seen from Table 2 that, compared with the positive current collector in Comparative Example 1, the electrical conductivity of the positive current collector obtained in Examples 1-10 did not deteriorate.

Resistivity (Ω m) = square resistance * thickness of aluminum layer, wherein, the square resistance test method includes: cutting the composite current collector into a sample of 20mm × 200mm, using the four-probe method to test the resistance of the central area of the sample, and the square resistance The unit of resistance is Ω, and the unit of aluminum layer thickness is m.

Example 11

Lithium batteries include:

Negative electrode: including a composite current collector and a negative electrode active material layer. The negative electrode active material layer is formed on the surface of the composite current collector. The negative electrode active slurry used in the negative electrode active material layer includes graphite, styrene-butadiene rubber, sodium carboxymethyl cellulose and water. , the composite current collector includes a polyphenylene sulfide support layer and a copper layer, and the copper layer is formed on the upper and lower surfaces of the polyphenylene sulfide support layer. The parameters in the composite current collector are shown in Table 3. The holes on the first conductive layer and the second The holes on the two conductive layers are relatively arranged, and the holes on the first conductive layer and the second conductive layer are evenly distributed;

Positive electrode: including positive electrode current collector aluminum foil and positive electrode active material layer (the positive electrode slurry forming the positive electrode active material layer includes lithium iron phosphate, PVDF, conductive carbon black and NMP);

Diaphragm: pp film;

Example 12

For the parameters of the composite current collector that constitutes the negative electrode in the lithium battery, refer to Table 3, the holes on the first conductive layer and the holes on the second conductive layer are arranged in a staggered manner, and the holes on the first conductive layer and the second conductive layer are evenly distributed, and the others are the same as Example 11.

Example 13

For the parameters of the composite current collector that constitutes the negative electrode in the lithium battery, refer to Table 3. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, and the adjacent holes on the first conductive layer are arranged in a staggered manner, and the holes on the second conductive layer are arranged oppositely. Adjacent holes are arranged in a staggered manner, and the others are the same as in Embodiment 11.

Example 14

For the parameters of the composite current collector that forms the negative electrode in the lithium battery, refer to Table 3. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, the holes on the first conductive layer are evenly distributed, and the adjacent holes on the second conductive layer Staggered arrangement, others are the same as embodiment 11.

Example 15

For the parameters of the composite current collector that constitutes the negative electrode in the lithium battery, refer to Table 3. The holes on the first conductive layer and the holes on the second conductive layer are staggered, the adjacent holes on the first conductive layer are staggered, and the holes on the second conductive layer are staggered. Evenly distributed, others are the same as in Example 11.

Example 16

For the parameters of the composite current collector that constitutes the negative electrode in the lithium battery, refer to Table 3. The holes on the first conductive layer and the holes on the second conductive layer are arranged staggered, and the adjacent holes on the first conductive layer are arranged staggered, and the holes on the second conductive layer are arranged staggered. Adjacent holes are arranged in a staggered manner, and the others are the same as in Embodiment 11.

Example 17

For the parameters of the composite current collector that constitutes the negative electrode in the lithium battery, refer to Table 3. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, and the distribution density of the holes on the first conductive layer away from the tab area is greater than that near the tab area. The distribution density of the holes on the area of the tab area, the distribution density of the holes on the area away from the tab area on the second conductive layer is greater than the distribution density of the holes on the area close to the tab area, and the others are the same as in Example 11.

Example 18

For the parameters of the composite current collector that constitutes the negative electrode in the lithium battery, refer to Table 3. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, the holes on the first conductive layer are evenly distributed, and the holes on the second conductive layer away from the tab area The distribution density of the holes on the region is greater than that on the region near the tab region, and the others are the same as in Example 11.

Example 19

For the parameters of the composite current collector that constitutes the negative electrode in the lithium battery, refer to Table 3. The holes on the first conductive layer and the holes on the second conductive layer are arranged oppositely, the holes on the second conductive layer are evenly distributed, and the holes on the first conductive layer away from the tab area The distribution density of the holes on the region is greater than that on the region near the tab region, and the others are the same as in Example 11.

Comparative example 2

There are no holes on the first conductive layer and the second conductive layer of the composite current collector that constitutes the negative electrode in the lithium battery, and the others are the same as in Example 11.

Each parameter of composite current collector in table 3 embodiment 11-19

Evaluate the weight loss of the negative electrode collectors obtained in Examples 11-19 and Comparative Example 2. Compared with the negative electrode collectors of Comparative Example 2, the negative electrode collectors obtained in Examples 11-19 have obvious weight loss, and the negative electrode collectors obtained in Examples 11-19 have obvious weight loss, and 11-19 The obtained lithium batteries have excellent cycle performance.

The resistivity of the negative electrode current collector obtained in Examples 11-19 and Comparative Example 2 was evaluated, and the characterization results are shown in Table 4.

Table 4 The resistivity characterization results of the negative electrode current collector obtained in Examples 11-19 and Comparative Example 2

the	负极集流体电阻率/Ω·mNegative electrode current collector resistivity/Ω·m
实施例11Example 11	2.2110 ^-8 2.2110 ^-8
实施例12Example 12	2.2210 ^-8 2.2210 ^-8
实施例13Example 13	2.1810 ^-8 2.18 ^10-8
实施例14Example 14	2.2110 ^-8 2.2110 ^-8
实施例15Example 15	2.1710 ^-8 2.1710 ^-8
实施例16Example 16	2.1610 ^-8 2.1610 ^-8
实施例17Example 17	2.210 ^-8 2.210 ^-8
实施例18Example 18	2.2110 ^-8 2.2110 ^-8
实施例19Example 19	2.2110 ^-8 2.2110 ^-8
对比例2Comparative example 2	2.2110 ^-8 2.2110 ^-8

It can be seen from Table 4 that, compared with the negative electrode current collector in Comparative Example 2, the electrical conductivity of the negative electrode current collectors obtained in Examples 11-19 did not deteriorate.

Resistivity (Ω m) = square resistance * copper layer thickness, wherein, the square resistance test method includes: cutting the composite current collector into a sample of 20mm × 200mm, using the four-probe method to test the resistance of the central area of the sample, and the square resistance The unit of resistance is Ω, and the unit of copper layer thickness is m.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the application and simplifying the description, rather than indicating or implying the referred device or Elements must have certain orientations, be constructed and operate in certain orientations, and thus should not be construed as limiting the application.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In this application, terms such as "installation", "connection", "connection" and "fixation" should be interpreted in a broad sense, for example, it can be a fixed connection or a detachable connection, unless otherwise clearly specified and limited. , or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limit. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

In the present application, unless otherwise clearly specified and limited, a first feature being "on" or "under" a second feature may mean that the first and second features are in direct contact, or that the first and second features are indirect through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present application, and those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims

A composite current collector, characterized in that it comprises:

support layer;

A conductive layer, the conductive layer is formed on the surface of the supporting layer, and holes are formed on the surface of the conductive layer, and the diameter of the holes is 10 μm to 500 μm.
The composite current collector according to claim 1, wherein the conductive layer has a thickness of 0.1 μm˜1.5 μm.
The composite current collector according to claim 1 or 2, characterized in that the diameter of the pores is 50 μm˜200 μm.
The composite current collector according to claim 1, characterized in that the center-to-center distance between adjacent holes is 30 μm˜5000 μm.
The composite current collector according to any one of claims 1-4, characterized in that the depth of the pores is 0.01 μm˜1.5 μm, and the depth of the pores is not greater than the thickness of the conductive layer.
The composite current collector according to claim 1, wherein the hole is a blind hole, and the distance between the bottom of the blind hole and the support layer is 0.01 μm˜1 μm.
The composite current collector according to any one of claims 1-6, characterized in that, the conductive layer includes a body region and a tab region, and the hole on the region of the conductive layer away from the tab region The distribution density of the holes is greater than the distribution density of the holes in the region close to the tab region.
The composite current collector according to any one of claims 1-6, wherein the conductive layer comprises a first conductive layer and a second conductive layer, and the first conductive layer is formed on the upper surface of the support layer above, the second conductive layer is formed on the lower surface of the support layer, and the holes are formed on both the first conductive layer and the second conductive layer.
The composite current collector according to claim 8, wherein the holes on the first conductive layer are arranged opposite to the holes on the second conductive layer.
The composite current collector according to claim 8, wherein the holes on the first conductive layer and the holes on the second conductive layer are arranged in a staggered manner.
The composite current collector according to any one of claims 8-10, characterized in that the pores on the first conductive layer and/or the second conductive layer are evenly distributed.
The composite current collector according to any one of claims 8-11, wherein a plurality of the holes are formed on the first conductive layer and the second conductive layer;

A plurality of the holes on the first conductive layer are arranged in an array; and/or

The plurality of holes on the second conductive layer are arranged in an array.
The composite current collector according to claim 12, wherein the holes in adjacent columns on the first conductive layer are arranged in a staggered manner; and/or

The holes in adjacent columns on the second conductive layer are arranged in a staggered manner.
The composite current collector according to any one of claims 1-13, wherein a plurality of holes are formed on the surface of the conductive layer, and at least some of the holes have the same shape.
The composite current collector according to any one of claims 1-14, wherein the holes are circular holes or polygonal holes.
A method for preparing the composite current collector according to any one of claims 1-15, comprising:

forming a conductive layer on the support layer;

A part of the conductive layer is vaporized by laser spot burning, so as to form holes in the conductive layer.
A method for preparing the composite current collector according to any one of claims 1-15, comprising:

forming a plurality of protrusions on the support layer;

Using magnetron sputtering to form a conductive layer on the support layer, the conductive layer surrounds and covers the plurality of protrusions;

Pickling the conductive layer to remove the plurality of protrusions and the conductive layer covering the surfaces of the plurality of protrusions, thereby forming holes on the conductive layer.
A pole piece, characterized in that it comprises:

Composite current collector;

An active material layer, the active material layer is formed on the conductive layer of the composite current collector and embedded in the hole, wherein the composite current collector is the composite current collector according to any one of claims 1-15 Or adopt the composite current collector that the method described in claim 16 or 17 obtains.
A battery, characterized in that the positive electrode and/or negative electrode of the battery adopts the pole piece according to claim 18.
An electric device, characterized by comprising the battery of claim 19.