WO2019153280A1 - Preparation method for current collector, battery, battery cell, and current collector - Google Patents

Abstract

Disclosed are a preparation method for a current collector, a battery, a battery cell, and a current collector. The preparation method comprises: heating and extruding a base membrane and a first metal layer to provide at least one slot on the base membrane; and welding the first metal layer and a second metal layer corresponding to the slot, such that the first metal layer and the second metal layer are connected. The present application enables the current densities of the first metal layer and the second metal layer to be balanced.

Description

Method for preparing current collector, battery, battery cell and current collector

[Technical Field]

The present application relates to the technical field of batteries, and relates to a method for preparing a current collector, a battery, a battery cell, and a current collector.

 【Background technique】

The current collector is used to collect the current generated by the active material of the battery to form a current for external output. Existing current collectors are typically copper foil or aluminum foil, and such current collectors are generally heavier. The inventors of the present invention have found that the weight of the current collector can be greatly reduced by using a current collector plated with a metal layer on the base film, and the current collector includes a base film and a conductive layer disposed on both sides of the base film, wherein the base The film is made of a lightweight material such as polyethylene. However, the base film made of such a material generally has a low electrical conductivity, resulting in an unbalanced current density of the metal layers on both sides of the base film.

 [Summary of the Invention]

In order to solve the above problems of the prior art current collector, the present application provides a method for preparing a current collector, a battery, a battery cell, and a current collector.

In order to solve the above technical problem, the present application further provides a method for preparing a current collector, the current collector comprising a base film and a first metal layer and a second metal layer respectively disposed on two sides of the base film, the preparation method The method includes: heating and pressing the base film and the first metal layer to provide at least one groove on the base film; soldering the first metal layer corresponding to the groove and the a second metal layer to connect the first metal layer and the second metal layer.

In order to solve the above technical problems, the present application further provides a current collector prepared according to the above preparation method, the first metal layer includes at least one metal thin film layer, and each layer of the metal thin film layer has a thickness of 0.001- 5 μm.

In order to solve the above technical problem, the present application further provides a battery cell including a positive electrode sheet, a negative electrode sheet, a separator layer and a casing, wherein the positive electrode sheet, the separator layer and the negative electrode sheet are stacked in the outer casing. The positive electrode sheet and/or the negative electrode sheet includes the above-described current collector and an active layer disposed on the current collector.

In order to solve the above technical problem, the present application further provides a battery including the above battery cell and a protection circuit board, and the protection circuit board and the battery cell are connected to protect the battery cell.

Compared with the prior art, the present application heats and extrudes the base film and the first metal layer to provide at least one groove on the base film; and the welding corresponding to the groove The first metal layer and the second metal layer are connected to the first metal layer and the second metal layer to balance current densities of the first metal layer and the second metal layer.

 [Description of the Drawings]

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings to be used in the embodiments will be briefly described below. Obviously, the drawings in the following description are only some of the present application. For the embodiments, those skilled in the art can obtain other drawings according to the drawings without any creative work.

1 is a schematic cross-sectional view of a current collector of a first embodiment of the present application;

Figure 2 is a schematic cross-sectional view of a current collector of a second embodiment of the present application;

Figure 3 is a schematic cross-sectional view of the first metal layer of Figure 2;

4 is a schematic cross-sectional view showing a metal thin film layer of a third embodiment of the present application;

Figure 5 is a schematic cross-sectional view showing the material of the metal thin film layer of Figure 4 including copper and nickel;

6 is a top plan view showing a first metal layer in a mesh shape according to a fourth embodiment of the present application;

7 is a top plan view showing a metal thin film layer in a strip shape according to a fifth embodiment of the present application;

8 is a schematic plan view of a metal thin film layer of a sixth embodiment of the present application;

9 is a schematic plan view of a metal thin film layer of a seventh embodiment of the present application;

10 is a schematic plan view of a metal thin film layer of an eighth embodiment of the present application;

Figure 11 is a top plan view showing the shape of a plurality of non-metallic regions in Figure 10 in a bow shape;

Figure 12 is a top plan view showing a metal thin film layer of a ninth embodiment of the present application;

Figure 13 is a top plan view showing the metal thin film layer of Figure 12 disposed on the base film;

Figure 14 is a top plan view showing a metal thin film layer of a tenth embodiment of the present application;

Figure 15 is a schematic cross-sectional view showing a current collector of an eleventh embodiment of the present application;

Figure 16 is a top plan view showing a base film of a thirteenth embodiment of the present application;

Figure 17 is a top plan view showing a base film of a fourteenth embodiment of the present application;

Figure 18 is a schematic cross-sectional view showing a current collector of a sixteenth embodiment of the present application;

Figure 19 is a schematic cross-sectional view showing a current collector of a seventeenth embodiment of the present application;

Figure 20 is a schematic cross-sectional view showing a current collector of an eighteenth embodiment of the present application;

Figure 21 is a developed plan view of the first metal layer and the second metal layer of Figure 20 connected by a tab;

Figure 22 is a developed plan view of the first metal layer and the second metal layer of Figure 20 connected by a tab;

Figure 23 is a schematic cross-sectional view showing a current collector of a nineteenth embodiment of the present application;

Figure 24 is a schematic cross-sectional view of the plurality of current collectors and tab connections of Figure 23;

Figure 25 is a schematic cross-sectional view showing a base film of a twentieth embodiment of the present application;

Figure 26 is a schematic cross-sectional view showing a current collector of a twentieth embodiment of the present application;

Figure 27 is a top plan view showing a base film of a twenty-first embodiment of the present application;

Figure 28 is a schematic cross-sectional view showing a current collector of a twenty-first embodiment of the present application;

Figure 29 is a schematic cross-sectional view showing a current collecting groove of a twenty-second embodiment of the present application;

Figure 30 is a schematic cross-sectional view showing a current collector of a twenty-second embodiment of the present application;

Figure 31 is a schematic flow chart showing a method of preparing the current collector of Figure 29;

32 is a schematic flow chart of a method for preparing a current collector according to a first embodiment of the present application;

33 is a schematic structural view of a battery cell of a first embodiment of the present application;

Figure 34 is a cross-sectional view of the battery cell of Figure 33 taken along line I-I';

Figure 35 is a schematic view showing the structure of a battery of the first embodiment of the present application.

【Detailed ways】

The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It is specifically noted that the following examples are merely illustrative of the present application, but are not intended to limit the scope of the application. In the same manner, the following embodiments are only partial embodiments of the present application, and not all of the embodiments, and all other embodiments obtained by those skilled in the art without creative efforts are within the scope of the present application.

The terms "first", "second", "third", "fourth", etc. (if present) in the specification and claims of the present application and the above figures are used to distinguish similar objects, and are not necessarily used for Describe a specific order or order. It is to be understood that the data so used may be interchanged where appropriate, such that the embodiments of the present application described herein can be implemented, for example, in a sequence other than those illustrated or described herein. In addition, the terms "comprises" and "comprises" and "the" and "the" are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to Those steps or units may include other steps or units not explicitly listed or inherent to such processes, methods, products or devices.

Referring to FIG. 1, FIG. 1 is a schematic cross-sectional view of a current collector according to a first embodiment of the present application. The current collector 10 disclosed in this embodiment includes at least a base film 11 and a first metal layer 12, and the first metal layer 12 is disposed on the base film 11, wherein the first metal layer 12 may be disposed on the first surface 111 of the base film 11. on. In other embodiments, the first metal layer 12 may be disposed on the second surface 112 of the base film 11.

The base film 11 of the present embodiment is a composite film of an organic material, and the composite film of the organic material may be PE (Polyethylene, polyethylene) and PET (Polyethylene). Terephthalate, polyethylene terephthalate) and PP (Polypropylene, polypropylene) composite film, PE and PP composite film or PP and PET composite film. Wherein, the composite film of the organic material is composited by using two or more organic materials using solventless glue, for example, PE and PP are combined by solventless glue to form a composite film of PE and PP. In other embodiments, the composite film of the organic material may also be PVC (Polyvinyl) Composite membrane of chloride, polyvinyl chloride and PP, PI (Polyimide Composite film of Film, polyimide film) and PP, composite film of PI and PE or composite film of PVC and PE.

The thickness of the base film 11 may be 1-100 μm, for example, the thickness of the base film 11 may be 5 μm or 3 μm. The thickness of the first metal layer 12 may be 0.001 to 10 μm, for example, the thickness of the first metal layer 12 is 0.05 μm, 0.1 μm, or 0.5 μm.

The first metal layer 12 may be disposed on the first surface 111 of the base film 11. The first metal layer 12 may be made of the first metal layer 12, and the first metal layer 12 may be disposed by bonding or the like. On the first surface 111.

The first metal layer 12 may be disposed on the first surface 111 of the base film 11 or may be evaporated to the first surface 111 of the base film 11 by vacuum evaporation. The first metal layer 12 is formed on the first surface 111 of the base film 11. In other embodiments, the first metal layer 12 is disposed on the first surface 111 by sputtering, sputtering, electroplating, or coating.

The base film 11 of the present embodiment is a composite film of an organic material, which can improve the stretching mildness and toughness of the current collector 10, and improve the production efficiency of the battery pole piece; in addition, the base film 11 of the current collector 10 is a composite film of an organic material. The weight of the current collector 10 can be reduced and the thickness of the current collector 10 can be reduced, thereby increasing the energy density of the battery, reducing the power of the current collector 10, and reducing the cost; in addition, the resistance of the composite film of the organic material is high, and the battery temperature is avoided. Rapid rise can improve the safety of the battery.

The present application provides a current collector of the second embodiment, which is described on the basis of the current collector 10 of the first embodiment. As shown in FIG. 2, the first metal layer 12 disclosed in this embodiment may include at least one layer of metal. Thin film layer 121. For example, the first metal layer 12 may include one, two or three metal thin film layers 121. It is understood that when the first metal layer 12 includes only one metal thin film layer 121, the metal thin film layer 121 is the first metal. The layer 12, specifically, each element such as the thickness, material, or shape of the metal thin film layer 121 is also a member such as the thickness, material, or shape of the first metal layer 12.

The thickness of each metal thin film layer 121 is 0.001-5 μm. For example, the thickness of each metal thin film layer 121 may be 0.05 μm, 0.1 μm, 0.2 μm or 1 μm.

The material of each metal thin film layer 121 may be one of copper, nickel, titanium, tin, zinc, iron, gold or silver or at least two composite alloys. For example, the material of each metal thin film layer 121 may be copper or Copper and nickel alloys.

In this embodiment, the square resistance of the first metal layer 12 is adjusted by setting the material of the metal thin film layer 121 to control the square resistance of the first metal layer 12 within a preset range, such as 0.001-10 Ω/m.

When the first metal layer 12 includes the plurality of metal thin film layers 121, the material of each of the metal thin film layers 121 may be the same. For example, the material of each of the metal thin film layers 121 is copper.

When the first metal layer 12 includes the plurality of metal thin film layers 121, the material of each of the metal thin film layers 121 may be different. As shown in FIG. 3, the first metal layer 12 includes a metal thin film layer sequentially disposed on the first surface 111. 121, 122 and 123, wherein the metal thin film layer 121 can be a copper thin film layer; the metal thin film layer 122 can be a nickel thin film layer; and the metal thin film layer 123 can be a tin thin film layer. Alternatively, the metal thin film layer 121 may be a tin thin film layer; the metal thin film layer 122 may be a copper thin film layer; and the metal thin film layer 123 may be a nickel thin film layer.

The metal thin film layer 121 close to the first surface 111 serves as an adhesion enhancing layer, and the metal thin film layer 121 serves to prevent the first metal layer 12 from falling off.

In this embodiment, the first metal layer 12 includes three metal thin film layers 121 as an example. In other embodiments, the first metal layer 12 may be provided with other metal film layers 121. For example, 5 or 8 layers.

The first metal layer 12 of the present embodiment includes at least one metal thin film layer 121, and the conductivity of the first metal layer 12 is adjusted by providing the material and/or the number of layers of the metal thin film layer 121.

The present application provides the current collector of the third embodiment, which is different from the current collector disclosed in the second embodiment in that the present embodiment is described by the metal thin film layer 121. As shown in FIG. 4, the metal thin film layer 121 is divided. For a plurality of regions 1211, the material of each region 1211 can be one of copper, nickel, titanium, tin, zinc, iron, gold or silver or at least two composite alloys to form a plurality of material combinations.

The description will be made with the material of the metal thin film layer 121 including copper and nickel. As shown in FIG. 5, the metal thin film layer 121 includes at least one first region 1212 and at least one second region 1213. The first region 1212 and the second region 1213 are disposed adjacent to each other, and the material of the first region 1212 and the second region 1213 are The material may be different, for example, the material of the first region 1212 may be copper, and the material of the second region 1213 may be nickel, and thus the metal thin film layer 121 is combined in a copper-nickel arrangement.

In other embodiments, the material of the metal thin film layer 121 may also be at least two materials of copper, nickel, titanium, tin, zinc, iron, gold, silver or alloy, and the alloy is copper, nickel, titanium, tin, zinc. At least two of iron, gold or silver may be combined, and at least two materials may be combined in different arrangements. For example, the metal thin film layer 121 is formed by a combination of copper nickel titanium or titanium nickel copper.

The material of the other metal thin film layer may be the same as the material of the metal thin film layer 121 of the present embodiment. In other embodiments, the material of the other metal thin film layer may be different from the material of the metal thin film layer 121 of the embodiment.

The metal thin film layer 121 of the present embodiment is divided into a plurality of regions 1211, and the material of each of the regions 1211 may be one of copper, nickel, titanium, tin, zinc, iron, gold or silver or at least two composite alloys. The conductivity of the first metal layer 12 can be adjusted.

The present application provides a current collector of the fourth embodiment, which is described on the basis of the current collector disclosed in the second embodiment. This embodiment is described with the first metal layer 12: as shown in FIG. 6, the first metal layer 12 includes a first metal region 141 disposed along a first direction and a second metal region 142 disposed along a second direction. The first metal region 141 and the second metal region 142 are disposed to intersect to form a mesh pattern, that is, the pattern of the first metal layer 12 is a mesh pattern. The material of the first metal region 141 and the material of the second metal region 142 may each be one or a combination of at least two of copper, nickel, titanium, tin, zinc, iron, gold or silver.

Wherein, the first metal region 141 and the second metal region 142 are vertically disposed, and the first metal region 141 and the second metal region 142 are connected at the intersection. The width of the first metal region 141 and the width of the second metal region 142 may be equal; in other embodiments, the width of the first metal region 141 and the width of the second metal region 142 are set to be unequal, and the first metal region 141 The angle at which the second metal region 142 meets may be an obtuse or acute angle.

The pattern of the first metal layer 12 of the present embodiment is a mesh pattern, which can reduce the material of the first metal layer 12, reduce the cost, and reduce the weight of the first metal layer 12.

The present application provides the current collector of the fifth embodiment, which is different from the current collector disclosed in the fourth embodiment in that, as shown in FIG. 7, the metal thin film layer 121 disclosed in the embodiment includes a plurality of spaced apart portions. A metal region 143, the plurality of first metal regions 143 are disposed in parallel with each other to form a stripe pattern, and the first metal region 143 may be disposed in a rectangular shape. The material of the first metal region 143 may be one of copper, nickel, titanium, tin, zinc, iron, gold or silver or a composite alloy of at least two.

The metal thin film layer 121 further includes a first connection line 144, and the plurality of first metal regions 143 are connected together by the first connection line 144.

The pattern of the metal thin film layer 121 of the present embodiment may be strip-shaped or linear, which can reduce the cost and reduce the weight of the first metal layer 12.

The present application provides the current collector of the sixth embodiment, which is different from the current collector disclosed in the fourth embodiment in that, as shown in FIG. 8, the metal thin film layer 121 of the present embodiment includes a plurality of spaced metal regions 145. The plurality of metal regions 145 are streamlined, and one end of the plurality of metal regions 145 is connected to the tabs 16 of the battery.

The material of each metal region 145 may be one of copper, nickel, titanium, tin, zinc, iron, gold or silver or at least two composite alloys.

Compared with the prior art, the metal thin film layer 121 of the present embodiment includes a plurality of spaced metal regions 145, and a blank region of the metal thin film layer 121 between the adjacent two metal regions 145 reduces material and can be reduced. Cost, and reduce the weight of the first metal layer 12.

The present application provides the current collector of the seventh embodiment, which is different from the current collector disclosed in the sixth embodiment in that, as shown in FIG. 9, the metal thin film layer 121 of the present embodiment includes a plurality of spaced metal regions 145. And a connecting line 146, which is disposed at one end of each metal region 145, and a plurality of metal regions 145 are connected to the tabs 16 of the battery through connecting wires 146. It will be understood that in other embodiments, the connecting wires 146 are The position can be adjusted according to the actual situation, and only the metal regions 145 are connected and connected to the tabs 16.

Compared with the prior art, the metal thin film layer 121 of the present embodiment includes a plurality of spaced metal regions 145, and a blank region of the metal thin film layer 121 between the adjacent two metal regions 145, thereby reducing material and reducing cost.

The present application provides the current collector of the eighth embodiment, which is different from the current collector disclosed in the fourth embodiment in that, as shown in FIG. 10, the metal thin film layer 121 includes at least one metal region 148 in an adjacent metal region. Between the 148 is disposed at least one non-metal region 147, and the material of the metal region 148 may be one of copper, nickel, titanium, tin, zinc, iron, gold or silver or at least two composite alloys; the non-metal region 147 It may be a blank area where no metal is provided, or a non-metal may be provided in the non-metal area 147, and the non-metal material may be PP, PET, PE, PVC or PI.

The at least one non-metallic region 147 may be a plurality of non-metallic regions 147, the plurality of non-metallic regions 147 being spaced apart, and each of the non-metallic regions 147 may be rectangular in shape, as shown in FIG. In other embodiments, the non-metallic region 147 may also be provided in other shapes, for example, the shape of the non-metallic region 147 is circular or square.

In addition, a plurality of non-metal regions 147 may be sequentially connected. As shown in FIG. 11, the plurality of non-metal regions 147 may have a bow shape. In other embodiments, the shape of the plurality of non-metallic regions 147 may be set to an I-shape, a diamond shape, a T-shape, or an L-shape.

In this embodiment, at least one non-metal region 147 is disposed between adjacent metal regions 148. The non-metal region 147 is a blank region or is provided with a non-metal, thereby reducing material and low cost.

The present application provides the current collector of the ninth embodiment, which is different from the current collector disclosed in the eighth embodiment in that, as shown in FIG. 12, the metal thin film layer 121 of the present embodiment includes a plurality of metal regions 140, and a plurality of The metal region 140 may specifically include a first metal region 1401, a plurality of second metal regions 1402, and a plurality of third metal regions 1403. The plurality of second metal regions 1401 are disposed on one side of the plurality of second metal regions 1402, and the plurality of third metal regions 1403 are disposed in one-to-one correspondence with the plurality of second metal regions 1402. Each of the second metal regions 1402 is connected to the first metal regions 1401 through the corresponding third metal regions 1403 such that the plurality of second metal regions 1402 are connected to the first metal regions 1401 through the third metal regions 1403.

The second metal region 1402 and the first metal region 1401 are connected together by a narrower third metal region 1403, and the third metal region 1403 can form a local high resistance for preventing excessive current and causing thermal failure of the battery.

As shown in FIG. 13, FIG. 13 is a top plan view showing the metal thin film layer of FIG. 12 disposed on the base film, wherein the distance d1 between the first metal region 1401 and the edge of the base film 11 may be 0-10 mm, for example, d1. 3 mm; the distance d2 between the second metal region 1402 and the edge of the base film 11 may be 0-10 mm, for example, d2 is 3 mm; the distance d3 between the first metal region 1401 and the second metal region 1402 may be 0.1 mm. -2 mm, for example d3 is 1 mm.

The area of the second metal region 1402 may be larger than the area of the first metal region 1401, and the area of the first metal region 1401 may be larger than the area of the third metal region 1403.

The second metal region 1402 of the present embodiment and the first metal region 1401 are connected together through the narrower third metal region 1403, and the third metal region 1403 can form a local high resistance to prevent the current from being excessively high and causing thermal failure of the battery.

The present application provides the current collector of the tenth embodiment, which is different from the current collector disclosed in the ninth embodiment in that, as shown in FIG. 14, the metal thin film layer 121 of the present embodiment includes a plurality of metal regions 247 and connecting lines. 248.

The plurality of metal regions 247 include a first metal region 2471, a plurality of second metal regions 2472, and a plurality of third metal regions 2473. The plurality of second metal regions 2472 are spaced apart, and the adjacent two second metal regions 2472 Connected by a connection line 248, the second metal region 2472 is coupled to the first metal region 2471 via a corresponding third metal region 2473. The shape of the plurality of second metal regions 2472 may be a rectangle. In other embodiments, the shape of the second metal region 2472 may be set to other shapes, for example, the shape of the second metal region 2472 is set to an L shape or a T shape.

This embodiment forms a blank area in the adjacent two second metal regions 2472, which can reduce the cost and reduce the weight of the first metal layer 12.

The present application provides the current collector of the eleventh embodiment, which is different from the current collector disclosed in the first embodiment in that, as shown in FIG. 15, the current collector 20 disclosed in the embodiment includes a base film 21 and a first The metal layer 22, the first metal layer 22 is disposed on one side of the base film 21. The first metal layer 22 includes at least one first region 221 and at least one second region 222. The thickness of the first region 221 is greater than the thickness of the second region 222, and the plurality of first regions 221 and the plurality of second regions 222 may be Set apart from each other.

The thickness of the second region 222 of the first metal layer 22 of the present embodiment is smaller than that of the first region 221 of the first metal layer 22, that is, the thickness is smaller than that of the first metal layer 12 disclosed in the first embodiment. The material of the local area of the first metal layer 22 is to reduce the cost.

The present application provides the current collector of the twelfth embodiment, which is different from the current collector disclosed in the first embodiment in that, as shown in FIG. 1, the base film 11 disclosed in the embodiment may be a non-woven fabric. The material of the nonwoven fabric may include a metal material, which may be one of copper, nickel, titanium, tin, zinc, iron, gold or silver or a composite alloy of at least two. The material of the non-woven fabric may also include a non-metal material, and the non-metal material may be PP, PET, PE, PVC, PI, nylon, inorganic material, alumina, magnesia, aluminum hydroxide, silicon dioxide and graphite. One or more of a mixture or carbon fiber.

The manufacturing process of the non-woven fabric is specifically: laying at least one metal material (or at least one metal material and non-metal material), for example, paving PP and copper; then, at least one metal after laying the net The material (or at least one of the metal material and the non-metal material) is reinforced to reinforce the laid PP and copper wire; at least one metal material (or at least one metal material and non-metal material) after the reinforcement Compounding and slitting, that is, compounding and slitting of the reinforced PP and copper. Among them, the specific process of the nonwoven fabric may include hydroentanglement, heat sealing, wet method, spunbonding or melt blowing.

Compared with the prior art copper foil or aluminum foil, the base film 11 of the present embodiment can be a non-woven fabric, which can improve the stretching mildness and toughness of the current collector, improve the production efficiency of the battery pole piece, and reduce the weight of the current collector. And reducing the thickness of the current collector, thereby increasing the energy density of the battery, reducing the power of the current collector, and reducing the cost.

The present application provides the current collector of the thirteenth embodiment, which is different from the current collector disclosed in the first embodiment in that the base film 31 disclosed in the embodiment may be a braid, and the braid includes the first A plurality of metal lines 311 disposed in the direction D1 and a plurality of non-metal lines 312 disposed along the second direction D2, wherein the metal lines 311 and the non-metal lines 312 are disposed to intersect, as shown in FIG. The material of the metal wire 311 may be one or at least two of copper, nickel, titanium, tin, zinc, iron, gold or silver; the material of the non-metal wire 312 may be PP, PET, PE, PVC, PI, nylon, inorganic materials, alumina, magnesia, aluminum hydroxide, a mixture of silica and graphite or carbon nanotubes.

The first direction D1 is perpendicular to the second direction D2, that is, the metal line 311 is perpendicular to the non-metal line 312. In other embodiments, the angle between the first direction D1 and the second direction D2 may be set to other angles, for example, the angle between the first direction D1 and the second direction D2 is 60° or 120°.

Compared with the prior art copper foil or aluminum foil, the current collector disclosed in the embodiment includes the base film 31, and the base film 31 may be a braid, which can reduce the thickness and weight of the current collector and reduce the cost. Further, since the plurality of metal wires 311 are disposed along the first direction D1, directional conduction can be achieved.

It can be understood that, in other embodiments, as shown in FIG. 16, the base film 31 further includes at least one connecting line 313, and the material of the connecting line 313 may be copper, nickel, titanium, tin, zinc, iron, gold or silver. One or at least two of the composite wires 313 are used to connect the respective metal wires 311. At this time, the current collector may include only the base film 31, and conduct current through the metal wire 311 of the base film 31 and the connection line 313 without providing a metal layer on the base film 31.

The present application provides the current collector of the fourteenth embodiment, which is different from the current collector disclosed in the first embodiment in that, as shown in FIG. 17, the base film 41 disclosed in the embodiment may be a braid, and the weaving The object may include a first braided wire 411 disposed along the first direction D1 and a second braided wire 412 disposed along the second direction D2, the first braided wire 411 and the second braided wire 412 intersecting.

The first braided wire 411 includes a plurality of first metal wires 413 and a plurality of first non-metal wires 414. The first metal wires 413 and the first non-metal wires 414 are disposed adjacent to each other. The second braided wire 412 includes a plurality of second metal wires 415 and a plurality of second non-metal wires 416, and the second metal wires 415 and the second non-metal wires 416 are disposed adjacent to each other. The material of the first metal wire 413 and the second metal wire 415 may each be one of copper, nickel, titanium, tin, zinc, iron, gold or silver or at least two composite alloys; the first non-metal wire 414 and The second non-metal wire 416 may be made of PP, PET, PE, PVC, PI, nylon, inorganic material, alumina, magnesia, aluminum hydroxide, a mixture of silica and graphite, or at least carbon nanotubes. One.

The first direction D1 and the second direction D2 are vertically disposed, that is, the first braided wire 411 and the second braided wire 412 are vertically disposed. In other embodiments, the angle between the first direction D1 and the second direction D2 may be set to other angles, for example, the angle between the first direction D1 and the second direction D2 is 60° or 120°.

Compared with the prior art copper foil or aluminum foil, the current collector disclosed in the embodiment includes the base film 41, and the base film 41 can be a braid, which can reduce the thickness and weight of the current collector and reduce the cost.

It is to be understood that in other embodiments, the current collector may include only the base film 41 and conduct current through the first metal line 413 and the second metal line 415 of the base film 41 without providing a metal layer on the base film 41. .

The present application provides the current collector of the fifteenth embodiment, which is different from the current collector disclosed in the first embodiment in that the material of the base film disclosed in the embodiment is a low conductivity material, and the low conductivity material includes a low conductivity. Conductive metal materials and low conductivity non-metallic materials.

The low conductivity metal material may be stainless steel; the low conductivity non-metal material may be graphite or carbon nanotubes or carbon fibers. The low conductivity material may also be a mixed material of a metal material and graphite or a mixture of a metal material and aluminum oxide, and the metal material may be one or at least two of copper, nickel, titanium, tin, zinc, iron, gold or silver. Kind of compound.

The present invention provides the current collector of the sixteenth embodiment. As shown in FIG. 18, the current collector 50 disclosed in this embodiment includes a base film 51 and a conductive layer 52. The conductive layer 52 is disposed on at least one surface of the base film 51. This embodiment will be described by taking the conductive layer 52 on the surface 511 of the base film 51 as an example. In other embodiments, a conductive layer 52 is disposed on opposite surfaces of the base film 51.

The material of the conductive layer 52 is a composite of carbon black and glue or a composite of carbon nanotubes and glue. The conductive layer 52 is provided on the surface 511 of the base film 51 by vapor deposition, sputtering, plating, sputtering, or coating.

The base film 51 disclosed in the present embodiment may be the base film 11 disclosed in the first embodiment, the base film disclosed in the eleventh embodiment, the base film 31 disclosed in the twelfth embodiment, and the thirteenth embodiment. The base film 41 disclosed in the example or the base film disclosed in the fourteenth embodiment.

The structure of the conductive layer 52 disclosed in this embodiment is the same as that of the first metal layer 12 disclosed in the above embodiments, and details are not described herein again.

The present application provides a current collector of the seventeenth embodiment, which is described on the basis of the current collector disclosed in the first embodiment. As shown in FIG. 19, the current collector 10 further includes a second metal layer 13, a first metal layer. 12 is disposed on the first surface 111 of the base film 11, and the second metal layer 13 is disposed on the second surface 112 of the base film 11, and the first surface 111 and the second surface 112 of the base film 11 are oppositely disposed.

The second metal layer 13 has the same structure as the first metal layer disclosed in the first embodiment to the eleventh embodiment, and details are not described herein again.

The material of the composite film in which the base film is an organic material according to the first embodiment and the base film of the fifteenth embodiment are low conductivity materials, and the first metal layer 12 and the second layer are not conductive or have poor conductivity, so the first metal layer 12 and the second layer The metal layer 13 cannot be electrically connected through the base film 11.

The present application provides the current collector of the eighteenth embodiment. As shown in FIG. 20, the current collector 60 disclosed in the embodiment includes a base film 61, a first metal layer 62 disposed on the first surface of the base film 61, and a setting. A second metal layer 63 on the second surface of the base film 61.

As shown in FIG. 21, the current collector 60 further includes a tab 64 that is coupled to the first metal layer 62 and the second metal layer 63 such that the first metal layer 62 and the second metal layer 63 are electrically passed through the tab 64. connection.

Wherein, the first region 621 of the first metal layer 62 is connected to the tab 64, the thickness of the first region 621 is greater than the thickness of other regions of the first metal layer 62; the second region 631 of the second metal layer 63 and the tab 64 The thickness of the second region 631 is greater than the thickness of other regions of the second metal layer 63 to reduce the impedance and increase the conductivity.

As shown in FIG. 21, the tabs 64 can be I-shaped conductive sheets, the first end 641 of the tabs 64 is coupled to the first metal layer 62, and the second end 642 of the tabs 64 is coupled to the second metal layer 63. In other embodiments, the tabs 64 can be provided as other shapes of conductive sheets, for example, the tabs 64 can be L-shaped conductive sheets as shown in FIG. 22, or the tabs 64 can be T-shaped conductive sheets.

The base film 61 disclosed in this embodiment may be the base film disclosed in the first embodiment or the base film disclosed in the fifteenth embodiment, and details are not described herein again. The first metal layer 62 disclosed in this embodiment may be the first metal layer disclosed in the first to eleventh embodiments. The second metal layer 63 disclosed in this embodiment is the above-described seventeenth embodiment. The second metal layer disclosed is not described here.

The current collector 60 of the present embodiment includes a tab 64. The tab 64 may be an I-shaped conductive strip, and the tab 64 is connected to the first metal layer 62 and the second metal layer 63 to make the first metal layer 62 and the second metal layer. 63 is connected by tabs 64; in addition, the thickness of the first region 621 of the first metal layer 62 adjacent to the tabs 64 is greater than the thickness of other regions of the first metal layer 62, and the second metal layer 63 is adjacent to the tabs 64. The thickness of the second region 631 is greater than the thickness of other regions of the second metal layer 63 to reduce the impedance and increase the conductivity.

The present application provides the current collector of the nineteenth embodiment. As shown in FIG. 23, the current collector 70 disclosed in the embodiment includes a base film 71, a first metal layer 72 disposed on the first surface of the base film 71, and a setting. a second metal layer 73 on the second surface of the base film 71, wherein the base film 71 is a composite film of the organic material disclosed in the first embodiment, the nonwoven fabric disclosed in the twelfth embodiment, and a fifteenth implementation The base film disclosed in the examples will not be described herein. When the base film 71 is a nonwoven fabric, the material of the nonwoven fabric includes a metal material and a non-metal material, and the nonwoven fabric has poor electrical conductivity.

As shown in FIG. 23, the base film 71 is provided with at least one through hole 711, and the first metal layer 72 and/or the second metal layer 73 extend into the through hole 711. The base film 71, the first metal layer 72, and the second metal layer 73 of the current collector 70 are heated and pressed to extrude the extruded base film 71 to the periphery, and then the base film 71 is disposed on the base film 71. At least one through hole 711; the extruded first metal layer 72 and the second metal layer 73 are connected through the through hole 711, that is, the first metal layer 72 and the second metal layer 73 extend into the through hole 711, so that the first A metal layer 72 and a second metal layer 73 are connected.

The through hole 711 may have a diameter of 0.001 to 0.05 mm. When the plurality of through holes 711 are provided in the base film 71, the plurality of through holes 711 may be provided on the base film 71 at predetermined intervals. In other embodiments, the plurality of through holes 711 may be randomly distributed on the base film 71.

As shown in FIG. 24, a plurality of current collectors 70 are stacked, and a plurality of current collectors 70 are connected to the tabs 74, and the first metal layer 72 and the second metal layer 73 and the poles of each current collector 70 can be welded. The ears 74 are welded together, and the welding methods include, but are not limited to, ultrasonic welding, electronic welding, laser welding, or cold welding.

The base film 71 of the present embodiment is provided with at least one through hole 711, and the first metal layer 72 and the second metal layer 73 are connected through the through hole 711, so that the current density of the first metal layer 72 and the second metal layer 73 can be equalized. Further, the base film 71 is a composite film of an organic material, which can reduce the weight of the current collector 70 and reduce the thickness of the current collector 70, thereby improving the energy density of the battery and reducing the cost.

The first metal layer 72 disclosed in this embodiment is the first metal layer disclosed in the first embodiment to the eleventh embodiment and the seventeenth embodiment, and the second metal layer 73 is in the seventeenth embodiment. The second metal layer disclosed is not described here.

The present application provides the current collector of the twentieth embodiment, which is different from the current collector disclosed in the nineteenth embodiment in that a first metal layer 72 and a second metal layer are disposed on the base film 71 as shown in FIG. Before the 73, at least one through hole 711 is provided in the base film 71, wherein the base film 71 is heated and pressed to provide at least one through hole 711 on the base film 71.

In an embodiment, after the first metal layer 72 is disposed on the first surface of the base film 71 and the second metal layer 73 is disposed on the second surface of the base film 71, the first metal layer 72 and/or the second metal A layer 73 extends into the through hole, wherein the first metal layer 72 and the second metal layer 73 on both sides of the through hole 711 are pressed to make the extruded first metal layer 72 and the second metal layer 73 is connected through the through hole 711.

In an embodiment, the connecting member 74 is received in the at least one through hole 711 to connect the first metal layer 72 and the second metal layer 73 through the connecting member 74. As shown in FIG. 26, the connecting member 74 can be Metal powder or metal conductor.

In one embodiment, the first metal layer 72 is disposed on the first surface and the second metal layer 73 is disposed on the second surface and the conductive layer is deposited by evaporation, sputtering, sputtering, plating, or coating. Provided on the inner wall of the through hole 711, the first metal layer 72 and the second metal layer 73 are connected by a conductive layer. The conductive layer may be the first metal layer 72 and/or the second metal layer 73, and thus the first metal layer 72 and the second metal layer 73 pass through the first metal layer 72 and/or the second metal layer 73 of the inner wall of the through hole 711. connection.

The first metal layer 72 and the second metal layer 73 of the present embodiment are connected, and the current densities of the first metal layer 72 and the second metal layer 73 can be equalized.

The present application provides the current collector of the twenty-first embodiment, which is different from the current collector disclosed in the twentieth embodiment in that, as shown in FIG. 27, the base film 81 includes a first region 811 and a second region 812. The base film 81 located in the second region 812 is provided with a through hole 813.

The first metal layer 82 is disposed on the first surface of the base film 81, and the second metal layer 83 is disposed on the second surface of the base film 81, as shown in FIG. 28, the first metal layer 82 of the present embodiment and/or The second metal layer 83 is a metal or an alloy having a melting point of less than 300 ° C. The metal may be one of cerium, mercury, lanthanum, cerium, tin, and indium. The alloy may be lanthanum, mercury, lanthanum, cerium, tin, indium. At least two composite alloys, such as an alloy of bismuth tin, include 58% bismuth and 42% tin. Therefore, the melting points of the first metal layer 82 and the second metal layer 83 are lower than the melting point of the base film 81.

The first metal layer 82 and the second metal layer 83 located in the second region 812 are heated, and the first metal layer 82 and the second metal layer 83 are melted to pass the first metal layer 82 and the second metal layer 83 through the plurality of The via holes 813 are connected, that is, the first metal layer 82, the second metal layer 83, and the base film 81 located in the second region 812 form tabs.

In this embodiment, by heating the first metal layer 82 and the second metal layer 83 located in the second region 801 such that the first metal layer 82 and the second metal layer 83 are connected through the plurality of through holes 813, the first The current density of the metal layer 82 and the second metal layer 83 is equalized.

The present application provides the current collector of the twenty-second embodiment, which is different from the current collector disclosed in the nineteenth embodiment in that the base film 91 and the first metal layer 92 of the current collector 90 are as shown in FIG. Heating and pressing, extruding the extruded base film 91 to the periphery, and further providing at least one groove 911 on the base film 91, the groove 911 being disposed on the first surface of the base film 91. The first metal layer 92 is extruded into the recess 911. In other embodiments, the recess 911 may be disposed on the second surface of the base film 91 or on the first surface and the second surface of the base film 91.

The first metal layer 92 and the second metal layer 93 corresponding to the groove 911 are welded to allow the first metal layer 92 and the second metal layer 93 to penetrate through the groove 911 for connection, as shown in FIG. The welding method may specifically be one of ultrasonic welding, electronic welding, laser welding or cold welding.

As shown in FIG. 31, the method for preparing the current collector 90 includes the following steps:

S311: heating and pressing the base film 91 of the current collector 90 and the first metal layer 92 disposed on the base film 91 to provide at least one groove 911 on the base film 91;

As shown in FIG. 29, the base film 91 and the first metal layer 92 of the current collector 90 are heated and pressed, and the extruded base film 91 is extruded to the periphery, thereby providing at least one concave on the base film 91. The groove 911 is disposed on the first surface of the base film 91. The first metal layer 92 is heated and extruded to squeeze the first metal layer 92 into the recess 911.

S312: soldering the first metal layer 92 and the second metal layer 93 corresponding to the recess 911 to connect the first metal layer 92 and the second metal layer 93.

The first metal layer 92 and the second metal layer 93 corresponding to the recess 911 are soldered so that the first metal layer 92 and the second metal layer 93 penetrate through the recess 911 to achieve connection, as shown in FIG. . The welding method may specifically be one of ultrasonic welding, electronic welding, laser welding or cold welding.

In this embodiment, the first metal layer 92 and the second metal layer 93 corresponding to the groove 911 are soldered so that the first metal layer 92 and the second metal layer 93 penetrate the groove 911 to achieve connection, which enables the first The current density of the metal layer 792 and the second metal layer 93 is equalized.

The present application provides a method for preparing a current collector of the first embodiment. As shown in FIG. 32, the preparation method disclosed in the embodiment includes the following steps:

S181: Providing a base film.

The base film may be a composite film of an organic material, and the composite film of the organic material may be a composite film of PE and PET and PP, a composite film of PE and PP, a composite film of PP and PET.

In an embodiment, the base film may be a non-woven fabric, and the material of the non-woven fabric may include a metal material, which may be one of copper, nickel, titanium, tin, zinc, iron, gold or silver or At least two composite alloys. In other embodiments, the metallic material may also be one or more of copper wire, nickel wire, titanium wire, tin wire, zinc wire, iron wire, gold wire or silver wire. In addition, the material of the non-woven fabric may also include non-metal materials, and the non-metal materials may be PP, PET, PE, PVC, PI, nylon, inorganic materials, alumina, magnesia, aluminum hydroxide, silica, and graphite. One or more of a mixture or carbon fiber.

In an embodiment, the base film may be the braid disclosed in the thirteenth embodiment.

In an embodiment, the base film may be the braid disclosed in the fourteenth embodiment above.

In an embodiment, the material of the base film is a low conductivity material.

S182: disposing a first metal layer on the base film.

Wherein, in a vacuum state, the material of the first metal layer is evaporated onto the first surface of the base film to provide a first metal layer on the first surface of the base film.

Alternatively, the material of the first metal layer is made into a first metal layer, and the first metal layer is disposed on the first surface by lamination or the like.

In other embodiments, the first metal layer is disposed on the first surface by sputtering, plating, sputtering, or coating.

The first metal layer disclosed in this embodiment may be the first metal layer disclosed in the second embodiment to the eleventh embodiment.

The base film of the present embodiment may be a composite film, a nonwoven fabric or a braid of an organic material, which can reduce the weight of the current collector and reduce the thickness of the current collector, thereby improving the energy density of the battery and reducing the cost.

The present application also provides the battery cell of the first embodiment, as shown in FIGS. 33-34, FIG. 33 is a schematic structural view of the battery cell of the first embodiment of the present application; FIG. 34 is the battery cell edge of FIG. A schematic cross-sectional view of I-I'. The battery cell 920 includes a positive electrode tab 921, a negative electrode tab 922, a diaphragm layer 923, and a housing 924. The positive electrode tab 921, the diaphragm layer 923, and the negative electrode tab 922 are stacked and disposed in the accommodating space 925 formed by the housing 924. A current collector 926 and an active layer 927 disposed on a current collector 926 are included. The negative electrode sheet 922 includes a current collector 928 and an active layer 929 disposed on the current collector 928. The current collector 926 can be the current collector disclosed in the above embodiment. 928 can be the current collector disclosed in the above embodiments, and details are not described herein again.

The positive electrode tab 921 is further provided with a positive electrode tab 930, and the negative electrode tab 922 is also provided with a negative electrode tab 931. The battery cell 920 completes the charging and discharging process through the positive electrode tab 930 and the negative electrode tab 931. The positive electrode tab 930 can be the tabs disclosed in the above embodiments, and the negative electrode tab 931 can be the tabs disclosed in the above embodiments, and details are not described herein again.

The battery cell 920 also needs to inject an electrolyte into the accommodating space 925 so that the positive electrode tab 921 and the negative electrode tab 922 are immersed in the electrolyte, and the electrolyte is used to cause the positive electrode tab 921 and the negative electrode tab 922 to perform charge transfer through the electrolyte. Further, the battery cell 920 is charged and discharged. The electrolyte is generally prepared from a high-purity organic solvent, an electrolyte lithium salt (lithium hexafluorophosphate), an additive, and the like under certain conditions and at a certain ratio.

The present application provides a battery of an embodiment. As shown in FIG. 35, the battery 190 disclosed in this embodiment protects the circuit board 191 and the battery cell 192. The protection circuit board 191 is connected to the battery cell 192, and the protection circuit board 191 is used. The battery cell 192 is protected, and the battery cell 192 is the battery cell disclosed in the above embodiment, and details are not described herein.

It should be noted that the above embodiments are all in the same inventive concept, and the descriptions of the respective embodiments are different, and the details are not described in the specific embodiments, and the descriptions in other embodiments may be referred to.

The protection circuit and the control system provided by the embodiments of the present application are described in detail above. The principles and implementation manners of the present application are described in the specific examples. The description of the above embodiments is only used to help understand the method of the present application. And the core ideas of the present invention; at the same time, those skilled in the art, according to the idea of the present application, there will be changes in the specific embodiments and application scopes. In summary, the contents of this specification should not be construed as limits.

Claims (13)

1. A method for preparing a current collector, wherein the current collector comprises a base film and a first metal layer and a second metal layer respectively disposed on two sides of the base film, and the preparation method comprises:

   Heating and pressing the base film and the first metal layer to provide at least one groove on the base film;

   The first metal layer and the second metal layer corresponding to the groove are welded to connect the first metal layer and the second metal layer.
2.  The method according to claim 1, wherein the heating and extruding the base film and the first metal layer comprises:

   The first metal layer is extruded into the recess.
3. The preparation method according to claim 1, wherein the welding comprises ultrasonic welding, electronic welding, laser welding or cold welding.
4. A current collector, characterized in that the current collector is prepared according to the method for preparing a current collector according to claims 1 to 11, the first metal layer comprising at least one metal thin film layer, each layer being The thickness of the metal thin film layer is 0.001 to 5 μm.
5. The current collector according to claim 4, wherein said metal thin film layer comprises a plurality of spaced apart metal regions, one end of each of said metal regions being connected to a tab of the battery.
6. The current collector according to claim 4, wherein said metal thin film layer comprises a plurality of spaced apart metal regions and connecting wires, and said plurality of metal regions are connected to the tabs of the battery through said connecting wires.
7. The current collector according to claim 4, wherein said metal thin film layer comprises at least one metal region, and at least one non-metallic region is disposed between adjacent metal regions.
8. The current collector according to claim 7, wherein said at least one non-metallic region is a plurality of non-metallic regions, and said plurality of said non-metallic regions are sequentially connected.
9. The current collector according to claim 4, wherein said first metal layer comprises at least one first region and at least one second region, said first region and said second region being disposed adjacent to said The material of the first region is different from the material of the second region.
10. The current collector according to claim 4, wherein the first metal layer has a thickness of 0.001 to 10 μm.
11. The current collector according to claim 4, wherein the pattern of the first metal layer is a mesh or a strip or a line pattern.
12. A battery cell characterized in that the battery cell comprises a positive electrode sheet, a negative electrode sheet, a separator layer and a casing, and the positive electrode sheet, the separator layer and the negative electrode sheet are laminated and disposed in the outer casing. The positive electrode sheet and/or the negative electrode sheet include the current collector according to claims 4 to 11 and an active layer disposed on the current collector.
13. A battery characterized by comprising the battery cell of claim 12 and a protection circuit board, the protection circuit board being connected to the battery cell for protecting the battery cell.