High-temperature-resistant PET-PI composite film structure of lithium battery

Abstract

The utility model relates to the technical field of membrane materials, and discloses a high-temperature-resistant PET-PI (Polyethylene Terephthalate-Polyimide) composite membrane structure of a lithium battery, which comprises an annular reticulated back material PI membrane, the oblique straight reticulate pattern base material PET film is fixedly attached to the bottom surface of the circular ring reticulate pattern back material PI film; the bottom surface of the oblique straight reticulate pattern base material PET film is coated with the laminated adhesive. According to the high-temperature-resistant PET-PI composite film structure of the lithium battery, the circular reticulated back material PI film and the oblique straight reticulated substrate PET film are overlapped, so that the material combination of the PET film and the PI film realizes good basic characteristics of ensuring insulation, high temperature resistance, excellent strength and the like, and the differentiated reticulated structure of the PET film and the PI film also provides excellent buffering and scratch-resistant and wear-resistant protection, so that the high-temperature-resistant PET-PI composite film structure of the lithium battery has the advantages of high temperature resistance, high temperature resistance, high heat resistance and the like. The scratch-resistant, wear-resistant and impact-resistant protection effects of the membrane material are greatly improved, and the safety protection performance is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of film materials, in particular to a high-temperature resistant PET-PI composite film structure for lithium batteries. Background Art

[0002] In the structure of a lithium battery, the separator is one of the key inner components. The performance of the separator determines the interface structure, internal resistance, etc. of the battery, directly affecting the characteristics such as the capacity, cycle, and safety performance of the battery. A separator with excellent performance plays an important role in improving the comprehensive performance of the battery. The main function of the separator is to separate the positive and negative electrodes of the battery to prevent the two poles from contacting and short-circuiting. In addition, it also has the function of allowing electrolyte ions to pass through.

[0003] The separator material of a lithium battery is non-conductive. For lithium battery series, since the electrolyte is an organic solvent system, a separator material resistant to organic solvents is required, and generally, high-strength films are used.

[0004] Currently, the separator structure used in lithium batteries on the market is basically a single-layer film structure. Although it can maintain the basic characteristics of high temperature resistance and good insulation, the single-layer film structure is difficult to achieve the protection effects of scratch resistance, wear resistance, and impact resistance, resulting in relatively general safety protection performance. Content of the Utility Model

[0005] Aiming at the deficiencies of the prior art, the utility model provides a high-temperature resistant PET-PI composite film structure for lithium batteries, solving the problems put forward in the above background art.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A high-temperature resistant PET-PI composite film structure for lithium batteries, comprising:

[0008] A circular mesh back material PI film;

[0009] An inclined straight mesh base material PET film, and the inclined straight mesh base material PET film is fixedly attached to the bottom surface of the circular mesh back material PI film;

[0010] A film laminating adhesive, and the film laminating adhesive is coated on the bottom surface of the inclined straight mesh base material PET film;

[0011] The circular mesh back material PI film includes a PI film body and a circular mesh, and the circular mesh is arranged on the top surface of the PI film body;

[0012] The inclined straight mesh base material PET film includes a PET film body and an inclined straight mesh, and the inclined straight mesh is arranged on the top surface of the PET film body;

[0013] Convex ring reticulation, the convex ring reticulation is arranged on the top surface of the PI film of the ring reticulation backing material, and the number of the convex ring reticulation is multiple and evenly distributed at equal intervals;

[0014] Intermittent diagonal reticulation, the intermittent diagonal reticulation is an intermittent linear convex strip structure, and the number of the intermittent diagonal reticulation is multiple and evenly distributed in parallel at equal intervals.

[0015] Preferably, the laminating adhesive is made of acrylate adhesive material, and the laminating adhesive is processed and coated on the bottom surface of the PET film of the straight diagonal reticulation substrate through a coater.

[0016] Preferably, the circular reticulation is an annular concave structure, and the number of the circular reticulation is multiple, and the multiple circular reticulations are evenly distributed at equal intervals on the top surface of the PI film body.

[0017] Preferably, the straight diagonal reticulation is an inclined linear groove structure, and the number of the straight diagonal reticulation is multiple, and the multiple straight diagonal reticulations are evenly distributed in parallel at equal intervals on the top surface of the PET film body.

[0018] Compared with the prior art, the beneficial effect of the present utility model is that: for the structure of the high-temperature resistant PET-PI composite film for lithium batteries, by setting the PI film of the ring reticulation backing material and the PET film of the straight diagonal reticulation substrate to overlap, the material combination of the PET film and the PI film realizes good basic characteristics such as ensuring insulation, high temperature resistance, and excellent strength. And the different reticulation structures of the two provide excellent buffering and scratch and wear resistance protection, greatly improving the protection effects of the film material against scratching, wear, and impact, and improving the safety protection performance. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the structure dissection of the present utility model;

[0020] Figure 2 It is a partially enlarged schematic diagram of the PI film of the ring reticulation backing material of the present utility model;

[0021] Figure 3 It is a partially enlarged schematic diagram of the PET film of the straight diagonal reticulation substrate of the present utility model.

[0022] In the figure: 1. PI film of the ring reticulation backing material; 2. PET film of the straight diagonal reticulation substrate; 3. Laminating adhesive; 4. Convex ring reticulation; 5. Intermittent diagonal reticulation; 101. PI film body; 102. Circular reticulation; 201. PET film body; 202. Straight diagonal reticulation. Detailed Embodiment

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] Referring to Figures 1-3 , a high-temperature resistant PET-PI composite film structure for lithium batteries, comprising:

[0025] A circular mesh back material PI film 1;

[0026] An inclined straight mesh base material PET film 2, and the inclined straight mesh base material PET film 2 is fixedly attached to the bottom surface of the circular mesh back material PI film 1;

[0027] A film laminating adhesive 3, and the film laminating adhesive 3 is coated on the bottom surface of the inclined straight mesh base material PET film 2;

[0028] The circular mesh back material PI film 1 includes a PI film body 101 and a circular mesh 102, and the circular mesh 102 is arranged on the top surface of the PI film body 101;

[0029] More specifically, the circular mesh 102 is arranged on the top surface of the PI film body 101 so that it is exposed to the outside, can directly bear the external abrasion, and is beneficial to protection and buffering;

[0030] The inclined straight mesh base material PET film 2 includes a PET film body 201 and an inclined straight mesh 202, and the inclined straight mesh 202 is arranged on the top surface of the PET film body 201;

[0031] A circular convex mesh 4, and the circular convex mesh 4 is arranged on the top surface of the circular mesh back material PI film 1, and the number of the circular convex meshes 4 is multiple and evenly distributed;

[0032] A segmented inclined mesh 5, and the segmented inclined mesh 5 is an intermittent linear convex strip structure, and the number of the segmented inclined meshes 5 is multiple and evenly distributed in parallel;

[0033] More specifically, by arranging the inclined straight mesh 202 on the top surface of the PET film body 201, the situation of unstable bonding of the film material due to being on the coating surface can be avoided.

[0034] In the present invention, the film laminating adhesive 3 is made of an acrylate adhesive material, and the film laminating adhesive 3 is processed and coated on the bottom surface of the inclined straight mesh base material PET film 2 by a coating machine;

[0035] More specifically, by using an acrylate adhesive material to make the film laminating adhesive 3, the drying and forming after processing are very rapid, and the transparency is good.

[0036] In the present utility model, the circular reticulation 102 is a circular ring-shaped concave structure, and the number of the circular reticulations 102 is multiple, and the multiple circular reticulations 102 are evenly distributed at equal intervals on the top surface of the PI film body 101;

[0037] More specifically, by arranging the multiple circular reticulations 102 to be evenly distributed at equal intervals on the top surface of the PI film body 101, the buffering of the structure against external scratching is made more uniform.

[0038] In the present utility model, the oblique straight reticulation 202 is an inclined linear groove structure, and the number of the oblique straight reticulations 202 is multiple, and the multiple oblique straight reticulations 202 are evenly distributed in parallel at equal intervals on the top surface of the PET film body 201;

[0039] More specifically, by arranging the multiple oblique straight reticulations 202 to be evenly distributed in parallel at equal intervals on the top surface of the PET film body 201, the buffering force is made more uniform.

[0040] Working principle: During use, the laminating adhesive 3 provides adhesion to the lithium battery structure and enables the attachment and assembly of the entire film material. The ring-shaped reticulation backsheet PI film 2 with differentiated reticulations and the oblique straight reticulation substrate PET film 3 are laminated, which can provide buffering, external impact protection, wear resistance, and scratch resistance.

[0041] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0042] Although the embodiments of the present utility model have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model, and the scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A high-temperature resistant PET-PI composite film structure for lithium batteries, characterized in that, Including: PI film (1) with a circular mesh back material; PET film (2) with an inclined straight mesh base material, and the PET film (2) with the inclined straight mesh base material is fixedly attached to the bottom surface of the PI film (1) with the circular mesh back material; Laminating adhesive (3), and the laminating adhesive (3) is coated on the bottom surface of the PET film (2) with the inclined straight mesh base material; The PI film (1) with the circular mesh back material includes a PI film body (101) and a circular mesh (102), and the circular mesh (102) is arranged on the top surface of the PI film body (101); The PET film (2) with the inclined straight mesh base material includes a PET film body (201) and an inclined straight mesh (202), and the inclined straight mesh (202) is arranged on the top surface of the PET film body (201); Circular convex mesh (4), and the circular convex mesh (4) is arranged on the top surface of the PI film (1) with the circular mesh back material. The number of the circular convex meshes (4) is multiple and they are evenly distributed at equal intervals; Interrupted inclined mesh (5), and the interrupted inclined mesh (5) is an intermittent linear convex strip structure. The number of the interrupted inclined meshes (5) is multiple and they are parallelly distributed at equal intervals.

2. The structure of a lithium battery high-temperature resistant PET-PI composite film according to claim 1, characterized in that The laminating adhesive (3) is made of acrylate adhesive material, and the laminating adhesive (3) is processed and coated on the bottom surface of the PET film (2) with the inclined straight mesh base material by a coater.

3. A high-temperature resistant PET-PI composite film structure for a lithium battery according to claim 2, characterized in that, The circular mesh (102) is a circular concave structure. The number of the circular meshes (102) is multiple, and the multiple circular meshes (102) are evenly distributed at equal intervals on the top surface of the PI film body (101).

4. A lithium battery high-temperature resistant PET-PI composite film structure according to claim 3, characterized in that, The inclined straight mesh (202) is an inclined linear groove structure. The number of the inclined straight meshes (202) is multiple, and the multiple inclined straight meshes (202) are parallelly distributed at equal intervals on the top surface of the PET film body (201).

Images