Diaphragm for lithium battery

Abstract

The utility model provides a diaphragm for a lithium battery, and relates to the technical field of lithium batteries. The diaphragm for the lithium battery comprises a base material layer, filtering layers are adhered to the two sides of the base material layer, outer film layers are adhered to the separated sides of the two filtering layers, a plurality of inner micropores are formed in the middle of the base material layer, a plurality of filtering holes are formed in the middle of each filtering layer, the base material layer contains a polypropylene material, and the outer film layers are adhered to the outer film layers. A polyethylene material is contained in the outer film layer, the multiple filtering holes penetrate through the middle of the filtering layer, the multiple inner micropores penetrate through the middle of the base material layer, the sections of the multiple inner micropores are arranged in a triangular shape, and the multiple inner micropores correspond to the multiple filtering holes. According to the diaphragm for the lithium battery, ions move to the position of the filtering layer through the outer membrane layer, the anti-blocking effect is achieved, contact points of the ions and the inner micropores can be reduced to the maximum extent, the blocking risk is effectively reduced due to reduction of the contact points, and then the effect of improving the using effect of the diaphragm is achieved.

Description

Technical Field

[0001] The utility model relates to a diaphragm for a lithium battery, belonging to the technical field of lithium batteries. Background Art

[0002] In the structure of lithium batteries, the diaphragm is one of the key internal components. The performance of the diaphragm determines the interface structure and internal resistance of the battery, and directly affects the battery's capacity, cycle and safety performance. A diaphragm with excellent performance plays an important role in improving the overall performance of the battery. The lithium battery diaphragm is an electrically insulating organic film with a porous structure. It is an important component of the lithium battery. Its main function is to block the positive and negative plates, isolate the negatively charged molecules from passing through, and prevent internal short circuits in the battery.

[0003] The comparative patent document publication number is: "A new type of lithium battery diaphragm of CN208608286U, including a membrane body, a substrate layer is provided at the middle position inside the membrane body, and a polyvinylidene fluoride diaphragm is provided at the middle position inside the substrate layer, polystyrene membranes are provided on both sides of the polyvinylidene fluoride diaphragm, and inner micropores are evenly provided inside the substrate layer, filter membranes are provided on both sides of the inner micropores, transition layers are provided on the outside of the substrate layer, and outer membrane layers are provided on the outside of the transition layers. The wavy micropores of the utility model can make ions pass through the micropores more uniformly and avoid clogging of the micropores. At the same time, filter membranes are provided on both sides of the micropores, and the filter screen of the transition layer can further ensure the continuous smooth flow of the micropores without deformation and clogging, thereby improving the performance and service life of the diaphragm."

[0004] The above patent still has the following problems in actual use: although the patent can perform daily barrier operations, the circular internal micropores have a large contact area with the passing ions, and the large contact area means an increased possibility of blockage, which in turn makes the anti-blocking effect of the diaphragm not good enough, and the use effect of the diaphragm is not good enough. Utility Model Content

[0005] (1) Technical problems solved

[0006] The utility model provides a diaphragm for a lithium battery, so as to solve the problem that the use effect of the diaphragm in the prior art is not good enough.

[0007] (2) Technical solution

[0008] The utility model is realized through the following technical scheme: a diaphragm for lithium batteries, including a substrate layer, filter layers are adhered on both sides of the substrate layer, outer film layers are adhered on the separated sides of the two filter layers, a plurality of inner micropores are opened in the middle of the substrate layer, and a plurality of filter holes are opened in the middle of the two filter layers.

[0009] Preferably, the base material layer contains polypropylene material, and the outer film layer contains polyethylene material.

[0010] Preferably, several of the filter holes penetrate the middle of the filter layer, and several of the inner micropores penetrate the middle of the substrate layer.

[0011] Preferably, the cross sections of the plurality of inner micropores are arranged in a triangular shape, and the plurality of inner micropores are opened corresponding to the plurality of filter holes.

[0012] The utility model provides a separator for lithium batteries, which has the following beneficial effects:

[0013] The lithium battery diaphragm achieves an anti-blocking effect by allowing ions to move through the outer membrane layer to the filter layer, so that the substrate layer, inner micropores, filter layer, filter holes, and outer membrane layer work together to minimize the contact points between ions and inner micropores. The reduction in contact points effectively reduces the risk of blockage, thereby improving the use effect of the diaphragm. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a three-dimensional diagram of the utility model;

[0015] Figure 2 It is a partial cross-sectional view of the utility model;

[0016] Figure 3 This is an exploded view of the present invention.

[0017]

Main component symbol description

[0018] 1. Base material layer; 2. Filter layer; 3. Outer membrane layer; 4. Inner micropores; 5. Filter holes. DETAILED DESCRIPTION

[0019] An embodiment of the utility model provides a separator for a lithium battery.

[0020] See also Figure 1 、 Figure 2 and Figure 3, including a substrate layer 1, the substrate layer 1 is made of polypropylene, polypropylene is a thermoplastic synthetic resin with excellent performance, a colorless, translucent, thermoplastic, lightweight general-purpose plastic with chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good high-wear-resistant processing performance, etc., and is widely used in the production of fiber products such as clothing and blankets, medical equipment, automobiles, bicycles, parts, pipelines, chemical containers, etc., and is also used for food and drug packaging. Filter layers 2 are pasted on both sides of the substrate layer 1, and the filter layers 2 perform filtering. The two filter layers 2 are pasted on the separated sides with outer film layers 3, and the outer film layer 3 is made of polyethylene. Polyethylene can be divided into high-density polyethylene, low-density polyethylene, linear low-density polyethylene and ultra-high molecular weight polyethylene according to the polymerization method, molecular weight and chain structure. It can not only protect the diaphragm, but also increase the hydrophilicity of the diaphragm. A number of inner micropores 4 are opened in the middle of the substrate layer 1, and a number of filter holes 5 are opened in the middle of the two filter layers 2.

[0021] Please refer again Figure 1 、 Figure 2 and Figure 3 It is worth mentioning that the substrate layer 1 contains polypropylene material, the outer film layer 3 contains polyethylene material, several filter holes 5 run through the middle of the filter layer 2, and several inner micropores 4 run through the middle of the substrate layer 1. The cross-sections of the several inner micropores 4 are triangular, and the several inner micropores 4 are opened corresponding to the several filter holes 5.

[0022] When the present invention is in use: first, the polyethylene material of the outer membrane layer 3 can not only protect the diaphragm, but also increase the hydrophilicity of the diaphragm; the polypropylene material of the substrate layer 1 can improve the chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good high-wear-resistant processing performance of the diaphragm; when ions are exchanged through the diaphragm, the ions first move to the position of the filter layer 2 through the outer membrane layer 3, and then under the filtration of the filter layer 2, a part of the particles are blocked and filtered, and then the filtered ions move to the substrate layer 1; the cross-section of the inner micropore 4 opened in the middle of the substrate layer 1 is triangular; the triangular inner micropore 4 can minimize the contact points between the ions and the inner micropore 4; the reduction of the contact points effectively reduces the risk of blockage, thereby improving the anti-blocking effect of the diaphragm, thereby achieving the effect of improving the use effect of the diaphragm.

[0023] Working principle: By moving ions through the outer membrane layer 3 to the filter layer 2, the ions are first filtered by the filter holes 5 and then pass through the triangular inner micropores 4, which can minimize the contact points between the ions and the inner micropores 4. The reduction in contact points effectively reduces the risk of blockage, thereby improving the anti-blocking effect of the diaphragm, thereby achieving the effect of improving the use effect of the diaphragm.

[0024] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. A lithium battery separator, comprising a substrate layer (1), characterized in that: Filter layers (2) are adhered to both sides of the substrate layer (1), and outer membrane layers (3) are adhered to the separated sides of the two filter layers (2). A plurality of inner micropores (4) are provided in the middle of the substrate layer (1), and a plurality of filter holes (5) are provided in the middle of the two filter layers (2). The cross sections of the plurality of inner micropores (4) are arranged in a triangular shape, and the plurality of inner micropores (4) are provided corresponding to the plurality of filter holes (5).

2. A lithium battery separator according to claim 1, characterized in that: The base material layer (1) contains polypropylene material, and the outer film layer (3) contains polyethylene material.

3. A lithium battery separator according to claim 1, characterized in that: A plurality of the filter holes (5) penetrate the middle of the filter layer (2), and a plurality of the inner micropores (4) penetrate the middle of the substrate layer (1).

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