Lithium battery diaphragm with interlayer

Abstract

The utility model relates to the technical field of lithium batteries, in particular to a lithium battery diaphragm with an interlayer, which comprises a polyethylene porous diaphragm layer, the polyethylene porous diaphragm layer comprises two base layers, a flame-retardant capsule is filled between the two base layers, W-shaped micropores are uniformly arranged in the two base layers, and the W-shaped micropores are filled in the polyethylene porous diaphragm layer. High-temperature-resistant layers are fixedly connected to the sides, away from each other, of the two base layers, heat conduction layers are fixedly connected to the sides, away from the base layers, of the two high-temperature-resistant layers, reinforcing layers are fixedly connected to the sides, away from the high-temperature-resistant layers, of the two heat conduction layers, and concave-convex layers are fixedly connected to the sides, away from the heat conduction layers, of the two reinforcing layers; the flame-retardant capsule is made of a mica material and a mica composite material, the two base layers are made of PE films or PP films, the two high-temperature-resistant layers are ceramic particle layers, and reinforcing ribs are uniformly arranged in the reinforcing layer, so that the strength and the high-temperature-resistant performance of the battery diaphragm are improved, and the safety is higher.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, specifically to a sandwich-type lithium battery separator. Background Technology

[0002] The separator is one of the four key materials in lithium batteries. Its main function is to separate the positive and negative electrodes to prevent short circuits caused by contact between the electrodes. In addition, the separator also allows electrolyte ions to pass through. The performance of the separator determines the battery's interface structure, internal resistance, etc., and directly affects the battery's capacity, cycle life, and safety performance. A high-performance separator plays an important role in improving the overall performance of the battery. However, existing separators have poor strength and insufficient high-temperature resistance. They are prone to shrinkage, deformation, and damage under high temperatures and external impacts, affecting the safe use of lithium batteries. Utility Model Content

[0003] The purpose of this invention is to provide a sandwich-type lithium battery separator to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A sandwich lithium battery separator includes a porous polyethylene separator layer, wherein the porous polyethylene separator layer includes two base layers, a flame-retardant capsule is filled between the two base layers, W-shaped micropores are uniformly formed inside the two base layers, a high-temperature resistant layer is fixedly connected to the side of each of the two base layers that is away from each other, a thermally conductive layer is fixedly connected to the side of each of the two high-temperature resistant layers that is away from the base layers, a reinforcing layer is fixedly connected to the side of each of the two thermally conductive layers that is away from the high-temperature resistant layers, and an uneven layer is fixedly connected to the side of each of the two reinforcing layers that is away from the thermally conductive layers.

[0006] As a preferred embodiment of this utility model, the flame-retardant capsule is made of mica material and mica composite material, and both base layers are made of PE film or PP film, which have good electrical insulation, thermal insulation, flame retardant properties and impact resistance.

[0007] As a preferred embodiment of this invention, both high-temperature resistant layers are ceramic particle layers, and both thermally conductive layers are graphene slurry layers, thereby improving the thermal conductivity and heat dissipation performance of the battery separator.

[0008] As a preferred embodiment of this invention, both of the uneven layers are made of polyethylene oxide, which increases the contact area with the electrolyte.

[0009] As a preferred embodiment of this utility model, the reinforcing layer is provided with reinforcing ribs evenly distributed inside, and the reinforcing ribs are arranged perpendicularly to each other in a mesh pattern, which can enhance the strength of the battery separator.

[0010] As a preferred embodiment of this utility model, the pore size of the W-shaped micropores is 0.05-0.08 μm, the thickness of the reinforcing layer is 2-3 μm, and the thickness of both base layers is 5-7 μm.

[0011] Compared with the prior art, the beneficial effects of this utility model are:

[0012] 1. In this utility model, by setting a high-temperature resistant layer and a heat-conducting layer inside the battery separator, the thermal conductivity and heat dissipation performance of the battery separator are effectively improved, and the probability of thermal shrinkage of the battery separator is reduced. At the same time, the flame-retardant capsule filled with it is made of mica material and mica composite material, which has good electrical insulation, thermal insulation, flame retardant performance and impact resistance.

[0013] 2. In this utility model, the strength of the battery separator can be enhanced by the reinforcing layer and the reinforcing ribs arranged in a mesh pattern inside the reinforcing layer. The uneven layer on the surface increases the contact area with the electrolyte, which is beneficial to improve ion permeability and increase the power of the lithium battery. The W-shaped micropores arranged in a W shape can inhibit the growth of lithium dendrites compared with straight vent holes, and prevent lithium dendrites from piercing the separator and causing a short circuit in the battery. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] Figure 2 This is a schematic diagram of the cross-sectional structure of this utility model;

[0016] Figure 3 This is a schematic diagram of the reinforcing layer of this utility model.

[0017] In the diagram: 1. Polyethylene porous membrane layer; 101. Base layer; 102. W-shaped micropores; 103. Flame retardant capsule; 2. High temperature resistant layer; 3. Thermally conductive layer; 4. Reinforcing layer; 5. Reinforcing ribs; 6. Textured layer. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0019] To facilitate understanding of this utility model, a more comprehensive description of the utility model will be given below with reference to the accompanying drawings, and several embodiments of the utility model will be provided. However, the utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the utility model more thorough and complete.

[0020] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] For examples, please refer to Figure 1 , Figure 2 This utility model provides a technical solution:

[0023] A sandwich lithium battery separator includes a porous polyethylene separator layer 1. The porous polyethylene separator layer 1 includes two base layers 101, and a flame-retardant capsule 103 is filled between the two base layers 101. W-shaped micropores 102 are uniformly opened inside the two base layers 101. A high-temperature resistant layer 2 is fixedly connected to the side of the two base layers 101 that is far away from each other. A thermally conductive layer 3 is fixedly connected to the side of the two high-temperature resistant layers 2 that is far away from the base layers 101. A reinforcing layer 4 is fixedly connected to the side of the two thermally conductive layers 3 that is far away from the high-temperature resistant layers 2. An uneven layer 6 is fixedly connected to the side of the two reinforcing layers 4 that is far away from the thermally conductive layers 3, which increases the contact area with the electrolyte.

[0024] like Figure 2 , Figure 3As shown, the flame-retardant capsule 103 is made of mica material and mica composite material, which has good electrical insulation, thermal insulation, flame retardant properties and impact resistance. The two base layers 101 are made of PE film or PP film. The two high-temperature resistant layers 2 are ceramic particle layers, which improve the thermal conductivity and heat dissipation performance of the battery separator. The two thermally conductive layers 3 are graphene slurry layers. The two uneven layers 6 are made of polyethylene oxide. The reinforcing layer 4 has reinforcing ribs 5 uniformly arranged inside. The reinforcing ribs 5 are arranged perpendicularly to each other in a mesh pattern, which can enhance the strength of the battery separator. The W-shaped micropores 102 have a pore size of 0.05 to 0.08 μm, which can inhibit the growth of lithium dendrites and prevent lithium dendrites from piercing the separator and causing a short circuit in the battery. The thickness of the reinforcing layer 4 is 2 to 3 μm, and the thickness of the two base layers 101 is 5 to 7 μm.

[0025] The working process of this utility model is as follows: During use, W-shaped micropores 102 are opened inside the two base layers 101. Compared with straight vent holes, these can inhibit the growth of lithium dendrites and prevent lithium dendrites from piercing the separator and causing a short circuit in the battery. At the same time, they can effectively increase the electrolyte adsorption of the lithium battery separator and improve its electrolyte retention capacity. The flame-retardant capsule 103 filled between the two base layers 101 is made of mica material and mica composite material, which has good electrical insulation, thermal insulation, flame retardant properties and impact resistance. The high-temperature resistant layer 2 and the thermally conductive layer 3 on both sides are respectively a ceramic particle layer and a graphene slurry layer. The ceramic particles further improve the high-temperature resistance of the separator, and the graphene slurry improves the thermal conductivity and heat dissipation of the battery separator. The reinforcing ribs 5 arranged in a mesh pattern inside the reinforcing layer 4 greatly enhance the strength of the battery separator. The uneven layer 6 on the surface increases the contact area with the electrolyte, which is beneficial to improve ion permeability and increase the power of the lithium battery.

[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A sandwiched lithium battery separator comprising a porous polyethylene separator layer (1), characterized in that: The polyethylene porous membrane layer (1) includes two base layers (101), and a flame-retardant capsule (103) is filled between the two base layers (101). W-shaped micropores (102) are uniformly opened inside the two base layers (101). A high-temperature resistant layer (2) is fixedly connected to the side of the two base layers (101) that is far away from each other. A heat-conducting layer (3) is fixedly connected to the side of the two high-temperature resistant layers (2) that is far away from the base layer (101). A reinforcing layer (4) is fixedly connected to the side of the two heat-conducting layers (3) that is far away from the high-temperature resistant layer (2). An uneven layer (6) is fixedly connected to the side of the two reinforcing layers (4) that is far away from the heat-conducting layer (3).

2. The lithium battery separator with interlayer according to claim 1, wherein: The flame-retardant capsule (103) is made of mica material and mica composite material, and both base layers (101) are made of PE film or PP film.

3. The sandwiched lithium battery separator of claim 1, wherein: Both of the high-temperature resistant layers (2) are ceramic particle layers, and both of the thermally conductive layers (3) are graphene slurry layers.

4. The sandwiched lithium battery separator of claim 1, wherein: Both of the aforementioned uneven layers (6) are made of polyethylene oxide.

5. The sandwiched lithium battery separator of claim 1, wherein: The reinforcing layer (4) is uniformly provided with reinforcing ribs (5), which are arranged in a mesh pattern perpendicular to each other.

6. The sandwiched lithium battery separator of claim 1, wherein: The W-shaped micropores (102) have a pore size of 0.05 to 0.08 μm, the reinforcing layer (4) has a thickness of 2 to 3 μm, and the two base layers (101) each have a thickness of 5 to 7 μm.

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