Bipolar current collector and lithium ion battery

Abstract

The utility model discloses a bipolar current collector and a lithium ion battery, the current collector comprises an anode metal covering layer, the anode metal covering layer comprises a first metal area and a first blank area which are alternately arranged; the negative electrode metal covering layer comprises a second metal region and a second blank region which are alternately arranged; the positive electrode metal covering layer and the negative electrode metal covering layer are respectively arranged on two surfaces of the base film layer; and the positive electrode metal covering layer and the negative electrode metal covering layer are made of different materials. The metal covering layers on the two surfaces of the base film layer are divided into the metal areas and the blank areas, and the metal areas and the blank areas are alternately arranged, so that when the base film layer is damaged, the positive electrode metal covering layer and the negative electrode metal covering layer are prevented from being in direct contact, and the short circuit condition is prevented; the base film layer is arranged to be of a porous structure, so that the electrolyte can penetrate through the base film layer through pores, and the electrolyte injection and infiltration efficiency is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of current collector production, and specifically relates to a bipolar current collector and a lithium ion battery. Background Art

[0002] The current collector is an important component of lithium-ion batteries. Its main function is to carry the electrode materials of the positive and negative electrodes, collect current and conduct electrons at the same time. The composite current collector is composed of a multi-layer structure. Due to its high safety and good conductivity, it has become the most promising new current collector material for lithium-ion batteries.

[0003] The base film layer of the composite current collector is relatively thin. When the base film layer is damaged, the positive electrode metal covering layer and the negative electrode metal covering layer may directly contact each other, resulting in a short circuit, thereby affecting the working performance of the lithium-ion battery.

[0004] Therefore, a bipolar current collector and a lithium-ion battery are designed to solve the above problems.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the utility model and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology section of the utility model. Utility Model Content

[0006] In order to overcome the above-mentioned deficiencies in the prior art, the purpose of the utility model is to provide a bipolar current collector and a lithium ion battery.

[0007] In order to achieve the above purpose and other related purposes, the technical solution provided by the utility model is: a bipolar current collector, comprising: a positive metal covering layer, the positive metal covering layer comprising a first metal region and a first blank region arranged alternately; a negative metal covering layer, the negative metal covering layer comprising a second metal region and a second blank region arranged alternately; a base film layer, the positive metal covering layer and the negative metal covering layer are arranged on the two surfaces of the base film layer respectively; the positive metal covering layer and the negative metal covering layer are made of different materials. In this solution, the metal covering layers on both surfaces of the base film layer are divided into metal regions and blank regions, and the metal regions and blank regions are arranged alternately, which can reduce or even avoid direct contact between the positive metal covering layer and the negative metal covering layer when the base film layer is damaged, thereby preventing the occurrence of a short circuit.

[0008] Furthermore, the first metal region and the first blank region are alternately arranged along the length direction of the bipolar current collector; the second metal region and the second blank region are alternately arranged along the length direction of the bipolar current collector. In this solution, the metal region and the blank region are alternately arranged along the length direction, which facilitates the production and processing of the bipolar current collector.

[0009] Furthermore, the base film layer is a porous structure; the first metal area is arranged corresponding to the second blank area, and the second metal area is arranged corresponding to the first blank area. In this scheme, the metal area of ​​the positive electrode (negative electrode) is arranged corresponding to the blank area of ​​the negative electrode (positive electrode), which can prevent the positive electrode metal covering layer and the negative electrode metal covering layer from directly contacting each other when the base film layer is damaged, thereby avoiding the occurrence of a short circuit. If the base film layer is arranged to be a porous structure, the base film layer can be directly used as a diaphragm, and the electrolyte can penetrate the base film layer through the pores and be transmitted in the vertical direction of the base film layer, thereby improving the electrolyte injection and infiltration efficiency.

[0010] Furthermore, the width of the first metal area is less than or equal to the width of the second blank area, and the width of the second metal area is less than or equal to the width of the first blank area. In this solution, the width of the metal area is not greater than the width of the blank area at the corresponding position, which can better avoid short circuits between the positive and negative electrodes.

[0011] Furthermore, the width of the first metal area is greater than 4 / 5 of the width of the second blank area; the width of the second metal area is greater than 4 / 5 of the width of the first blank area. In this solution, under the premise of avoiding short circuit between positive and negative electrodes, it is ensured that the metal area occupies a sufficient proportion in the overall structure to ensure the stability of the overall structure.

[0012] Furthermore, the width of the first blank area and the width of the second blank area are both 2 to 3 cm. In this solution, the width of the first blank area is 2 cm, 2.5 cm or 3 cm; the width of the second blank area is 2 cm, 2.5 cm or 3 cm.

[0013] Furthermore, the thickness of the first metal region is 0.15-18 μm, and the thickness of the second metal region is 0.15-18 μm. In this solution, the thickness of the first metal region is 0.15 μm, 10 μm or 18 μm; the thickness of the second metal region is 0.15 μm, 10 μm or 18 μm.

[0014] Furthermore, the porosity of the base membrane layer is 12-68%; the average pore size of the base membrane layer is 0.002-0.9 μm. In this solution, by setting a certain porosity and pore size for the base membrane layer, the efficiency of the electrolyte penetrating the base membrane layer through the pores is guaranteed.

[0015] Furthermore, the thickness of the base film layer is 1.5 to 90 μm; the material of the base film layer includes a polymer, and the polymer includes any one or a combination of at least two of polyethylene, polypropylene, polyethylene terephthalate, polyimide or polyphenylene sulfide. In this embodiment, the thickness of the base film layer is 1.5 μm, 20 μm or 90 μm.

[0016] The utility model also provides a lithium ion battery, which comprises the bipolar current collector described in any one of the above technical solutions.

[0017] Due to the application of the above technical solution, the utility model has the following beneficial effects compared with the prior art:

[0018] The bipolar current collector designed in the utility model divides the metal covering layers on both surfaces of the base membrane layer into metal areas and blank areas, and arranges the metal areas and blank areas alternately, which can reduce or even avoid direct contact between the positive metal covering layer and the negative metal covering layer when the base membrane layer is damaged, thereby preventing the occurrence of short circuits; the base membrane layer is arranged to have a porous structure, so that the electrolyte can penetrate the base membrane layer through the pores and be transmitted in the vertical direction of the base membrane layer, thereby improving the electrolyte injection and infiltration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the cross-sectional structure of the bipolar current collector of the utility model;

[0020] In the above figures, 1, positive electrode metal covering layer; 101, first metal area; 102, first blank area; 2, negative electrode metal covering layer; 201, second metal area; 202, second blank area; 3, base film layer. DETAILED DESCRIPTION

[0021] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0022] It should be noted that in the description of the present utility model, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the utility model product is usually placed when in use, which are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. Terms such as "horizontal", "vertical", and "overhanging" do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0025] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0026] Embodiment 1: See attached Figure 1As shown, this embodiment provides a bipolar current collector, including: a positive metal covering layer 1, the positive metal covering layer 1 includes a first metal region 101 and a first blank region 102 that are alternately arranged; a negative metal covering layer 2, the negative metal covering layer 2 includes a second metal region 201 and a second blank region 202 that are alternately arranged; a base film layer 3, the positive metal covering layer 1 and the negative metal covering layer 2 are respectively arranged on the two surfaces of the base film layer 3; the positive metal covering layer 1 and the negative metal covering layer 2 are made of different materials. In this embodiment, the metal covering layers on both surfaces of the base film layer 3 are divided into metal regions and blank regions, and the metal regions and blank regions are alternately arranged, which can reduce or even avoid direct contact between the positive metal covering layer and the negative metal covering layer when the base film layer 3 is damaged, thereby preventing the occurrence of a short circuit.

[0027] Embodiment 2: See attached Figure 1 As shown, this embodiment is a further improvement on the basis of the first embodiment, and its specific method is: the first metal region 101 and the first blank region 102 are alternately arranged along the length direction of the bipolar current collector; the second metal region 201 and the second blank region 202 are alternately arranged along the length direction of the bipolar current collector. In this embodiment, the metal region and the blank region are alternately arranged along the length direction, which is convenient for the production and processing of the bipolar current collector.

[0028] Embodiment 3: Not shown in the accompanying drawings, this embodiment is a further improvement on the basis of Embodiment 2, and its specific method is as follows: the base film layer 3 is a porous structure; the first metal area 101 is set corresponding to the second blank area 202, and the second metal area 201 is set corresponding to the first blank area 102. In this embodiment, the metal area of ​​the positive electrode (negative electrode) corresponds to the blank area of ​​the negative electrode (positive electrode), which can prevent the positive electrode metal covering layer 1 and the negative electrode metal covering layer 2 from directly contacting each other when the base film layer 3 is damaged, thereby avoiding the occurrence of a short circuit. If the base film layer 3 is set to a porous structure, the base film layer 3 can be used directly as a diaphragm, and the electrolyte can penetrate the base film layer 3 through the pores and be transmitted in the vertical direction of the base film layer 3, thereby improving the electrolyte injection and infiltration efficiency.

[0029] Embodiment 4: See attached Figure 1 As shown, this embodiment is a further improvement on the basis of the third embodiment, and its specific manner is: the width of the first metal region 101 is less than or equal to the width of the second blank region 202, and the width of the second metal region 201 is less than or equal to the width of the first blank region 102. In this embodiment, the width of the metal region is not greater than the width of the blank region at the corresponding position, which can better avoid short circuits between the positive and negative electrodes.

[0030] Embodiment 5: See attached Figure 1As shown, this embodiment is a further improvement on the basis of the fourth embodiment, and its specific manner is: the width of the first metal region 101 is greater than 4 / 5 of the width of the second blank region 202; the width of the second metal region 201 is greater than 4 / 5 of the width of the first blank region 102. In this embodiment, under the premise of avoiding the short circuit between the positive and negative electrodes, it is ensured that the metal region occupies a sufficient proportion in the overall structure, thereby ensuring the stability of the overall structure.

[0031] Embodiment 6: Not shown in the drawings, this embodiment is a further improvement on the basis of Embodiment 1, and its specific method is as follows: the width of the first blank area 102 and the width of the second blank area 202 are both 2 to 3 cm. Among them, the width of the first blank area 102 is 2 cm, 2.5 cm or 3 cm; the width of the second blank area 202 is 2 cm, 2.5 cm or 3 cm.

[0032] Embodiment 7: Not shown in the drawings, this embodiment is a further improvement on the basis of Embodiment 1, and its specific method is as follows: the thickness of the first metal region 101 is 0.15-18 μm, and the thickness of the second metal region 201 is 0.15-18 μm. Among them, the thickness of the first metal region 101 is 0.15 μm, 10 μm or 18 μm; the thickness of the second metal region 201 is 0.15 μm, 10 μm or 18 μm.

[0033] Embodiment 8: Not shown in the drawings, this embodiment is a further improvement on the basis of Embodiment 1, and its specific method is as follows: the porosity of the base membrane layer 3 is 12-68%; the average pore size of the base membrane layer 3 is 0.002-0.9 μm. Among them, the porosity of the base membrane layer 3 is 12%, 30% or 68%; the average pore size of the base membrane layer 3 is 0.002 μm, 0.5 μm or 0.9 μm. In this embodiment, by setting a certain porosity and pore size for the base membrane layer 3, the efficiency of the electrolyte penetrating the base membrane layer 3 through the pores is guaranteed.

[0034] Embodiment 9: Not shown in the drawings, this embodiment is a further improvement on the basis of Embodiment 1, and its specific method is as follows: the thickness of the base film layer 3 is 1.5 to 90 μm; the material of the base film layer 3 includes a high molecular polymer, and the high molecular polymer includes any one of polyethylene, polypropylene, polyethylene terephthalate, polyimide or polyphenylene sulfide or a combination of at least two thereof. The thickness of the base film layer 3 is 1.5 μm, 20 μm or 90 μm.

[0035] Embodiment 10: A lithium-ion battery, the lithium-ion battery comprising the bipolar current collector of any one of the above embodiments 1 to 9.

[0036] The bipolar current collector designed in the utility model divides the metal covering layers on both surfaces of the base membrane layer into metal areas and blank areas, and arranges the metal areas and blank areas alternately, which can reduce or even avoid direct contact between the positive metal covering layer and the negative metal covering layer when the base membrane layer is damaged, thereby preventing the occurrence of short circuits; the base membrane layer is arranged to have a porous structure, so that the electrolyte can penetrate the base membrane layer through the pores and be transmitted in the vertical direction of the base membrane layer, thereby improving the electrolyte injection and infiltration efficiency.

[0037] The above implementation modes are only for illustrating the technical concept and features of the utility model, and their purpose is to allow people familiar with this technology to understand the content of the utility model and implement it. It cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A bipolar current collector, characterized in that: include: A positive electrode metal covering layer (1), the positive electrode metal covering layer (1) comprising first metal regions (101) and first blank regions (102) arranged alternately; A negative electrode metal covering layer (2), the negative electrode metal covering layer (2) comprising second metal regions (201) and second blank regions (202) that are alternately arranged; A base film layer (3), wherein the positive electrode metal covering layer (1) and the negative electrode metal covering layer (2) are respectively arranged on two surfaces of the base film layer (3); The positive electrode metal covering layer (1) and the negative electrode metal covering layer (2) are made of different materials.

2. A bipolar current collector according to claim 1, characterized in that: The first metal regions (101) and the first blank regions (102) are alternately arranged along the length direction of the bipolar current collector; and the second metal regions (201) and the second blank regions (202) are alternately arranged along the length direction of the bipolar current collector.

3. A bipolar current collector according to claim 2, characterized in that: The base film layer (3) is a porous structure; the first metal region (101) is arranged corresponding to the second blank region (202), and the second metal region (201) is arranged corresponding to the first blank region (102).

4. A bipolar current collector according to claim 3, characterized in that: The width of the first metal region (101) is smaller than or equal to the width of the second blank region (202), and the width of the second metal region (201) is smaller than or equal to the width of the first blank region (102).

5. A bipolar current collector according to claim 4, characterized in that: The width of the first metal region (101) is greater than 4 / 5 of the width of the second blank region (202); and the width of the second metal region (201) is greater than 4 / 5 of the width of the first blank region (102).

6. A bipolar current collector according to claim 1, characterized in that: The width of the first blank area (102) and the width of the second blank area (202) are both 2 to 3 cm.

7. A bipolar current collector according to claim 1, characterized in that: The thickness of the first metal region (101) is 0.15 to 18 μm, and the thickness of the second metal region (201) is 0.15 to 18 μm.

8. A bipolar current collector according to claim 1, characterized in that: The porosity of the base film layer (3) is 12 to 68%; the average pore size of the base film layer (3) is 0.002 to 0.9 μm.

9. A bipolar current collector according to claim 1, characterized in that: The thickness of the base film layer (3) is 1.5 to 90 μm; the material of the base film layer (3) includes a high molecular polymer, and the high molecular polymer includes any one of polyethylene, polypropylene, polyethylene terephthalate, polyimide or polyphenylene sulfide, or a combination of at least two thereof.

10. A lithium ion battery, characterized in that: The lithium-ion battery comprises the bipolar current collector according to any one of claims 1 to 9.

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