Diaphragm and battery

Abstract

The utility model discloses a diaphragm and a battery, the diaphragm comprises a diaphragm main body and a polytetrafluoroethylene layer arranged on at least one side of the diaphragm main body, and the thickness of the polytetrafluoroethylene layer is 0.01-0.10 mm. In the embodiment, the polytetrafluoroethylene layer is arranged on the diaphragm main body, and the compact structure of the polytetrafluoroethylene layer is distributed on the surface of the diaphragm main body, so that the puncture resistance of the diaphragm main body is enhanced. Therefore, the diffusion of zincate ions can be effectively inhibited, and oxygen generated by the positive electrode during charging can be ensured to smoothly reach the zinc negative electrode for reduction reaction. Besides, due to the arrangement of the polytetrafluoroethylene layer, the diaphragm is endowed with certain hydrophobicity, so that the electrolyte is stably adsorbed in the diaphragm, and the service life of the battery is remarkably prolonged.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a separator and a battery. Background Technology

[0002] With continuous technological advancements and increased environmental awareness, batteries are playing an increasingly important role as energy storage devices in daily life and industrial applications. Among them, nickel-zinc batteries have received widespread attention due to their advantages such as high energy density, environmental friendliness, and cost-effectiveness. However, despite their numerous advantages, nickel-zinc batteries still face some technical challenges in practical use, especially the selection of separator materials, which are directly related to battery stability and lifespan.

[0003] During the operation of nickel-zinc batteries, the zinc electrode undergoes an oxidation reaction during discharge, generating zincate ions. If these ions diffuse and migrate uncontrollably towards the positive electrode, they not only increase the internal resistance of the battery, affecting its performance, but may also promote the growth of zinc dendrites. Zinc dendrites can easily penetrate the separator, causing internal short circuits and significantly reducing battery safety and cycle life. Furthermore, water is consumed during discharge, so the separator also needs to have good liquid absorption to maintain electrolyte balance within the battery.

[0004] Currently, to address the aforementioned issues, the common practice is to coat the zinc electrode with several layers of regenerated cellulose or polypropylene membranes. These materials can, to some extent, prevent the diffusion and migration of zincate ions towards the positive electrode, while also inhibiting the growth of zinc dendrites. However, this method also has significant drawbacks: on the one hand, while it effectively blocks ion migration, it also hinders the flow of gas (mainly oxygen generated at the positive electrode during charging) through the membrane to the zinc negative electrode surface for the necessary reduction reaction; on the other hand, existing membrane materials often fail to simultaneously meet the requirements of good permeability, strong liquid absorption, and sufficient mechanical strength. Utility Model Content

[0005] This invention provides a separator and a battery to solve the problems of poor puncture resistance and liquid retention of existing separator paper.

[0006] Specifically, the present invention provides a diaphragm, including a diaphragm body and a polytetrafluoroethylene layer disposed on at least one side of the diaphragm body, wherein the thickness of the polytetrafluoroethylene layer is 0.01 mm to 0.10 mm.

[0007] Optionally, the ratio of the thickness of the polytetrafluoroethylene layer to the thickness of the membrane body is 1:(0.1~10).

[0008] Optionally, the polytetrafluoroethylene layer is formed by interlacing polytetrafluoroethylene fibers.

[0009] Optionally, the diaphragm body includes a base membrane, and the polytetrafluoroethylene layer is disposed on the base membrane.

[0010] Optionally, the membrane body includes a base membrane and a functional coating, the functional coating being disposed on both sides of the base membrane; at least one side of the functional coating facing away from the base membrane is provided with the polytetrafluoroethylene layer.

[0011] Optionally, the functional coating is layer, layer, layer, One of the following: layer, PEDOT / PSS layer, MgO layer, graphene / carbon nanotube layer, polydopamine (PDA) layer, ceramic coating, artificial SEI layer, sulfide / oxide electrolyte layer.

[0012] Optionally, the polytetrafluoroethylene (PTFE) layer is hot-pressed onto the diaphragm body; or, the PTFE layer is bonded to the diaphragm body; or, the PTFE layer is formed by interlacing PTFE fibers sprayed onto the diaphragm body.

[0013] Optionally, the polytetrafluoroethylene layer is disposed on one side of the diaphragm body; or, the polytetrafluoroethylene layer is disposed on both sides of the diaphragm body.

[0014] This utility model also provides a battery, including a positive electrode, a negative electrode, and a separator as described in any one of the above, wherein the separator is disposed between the positive electrode and the negative electrode.

[0015] The beneficial effects of this utility model are as follows:

[0016] The separator and battery provided by this invention feature a polytetrafluoroethylene (PTFE) layer on the separator body. The dense structure of the PTFE layer on the separator body enhances the separator's puncture resistance. This effectively inhibits the diffusion of zincate ions and ensures that oxygen generated at the positive electrode during charging can smoothly reach the zinc negative electrode for reduction. Furthermore, the PTFE layer imparts a degree of hydrophobicity to the separator, allowing the electrolyte to be firmly adsorbed within the separator body, thus significantly extending the battery's lifespan. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a schematic structural diagram of the diaphragm in one embodiment of the present invention;

[0019] Figure 2 This is a schematic structural diagram of the diaphragm in one embodiment of the present invention.

[0020] In the diagram: 100, membrane body; 110, base membrane; 120, functional coating; 200, polytetrafluoroethylene layer.

[0021] A. Thickness of the polytetrafluoroethylene layer; B. Thickness of the diaphragm body. Detailed Implementation

[0022] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0023] In the description of this utility model, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] Figure 1 This is a schematic structural diagram of a battery assembly according to one embodiment of the present invention, as shown below. Figure 1 As shown, and refer to Figure 2 This utility model provides a diaphragm, including a diaphragm body 100 and a polytetrafluoroethylene (PTFE) layer 200 disposed on at least one side of the diaphragm body 100, wherein the thickness of the PTFE layer 200 is 0.01 mm to 0.10 mm. In application, the electrolyte enters the diaphragm body 100 around the perimeter of the diaphragm laminate structure.

[0026] In this embodiment, the presence of a polytetrafluoroethylene (PTFE) layer 200 on the separator body 100, with its dense structure distributed on the surface of the separator body 100, enhances the puncture resistance of the separator body 100. This effectively inhibits the diffusion of zincate ions and ensures that the oxygen generated at the positive electrode during charging can smoothly reach the zinc negative electrode for reduction reaction. Furthermore, the PTFE layer 200 also imparts a certain degree of hydrophobicity to the separator, allowing the electrolyte to be stably adsorbed within the separator body 100, thereby significantly extending the battery's lifespan.

[0027] The ratio of the thickness A of the polytetrafluoroethylene layer 200 to the thickness B of the membrane body 100 is 1:(0.1~10). A ratio of A to B of 1:(0.1~10) ensures sufficient puncture resistance, effectively inhibits the migration and diffusion of zincate ions, maintains good air permeability to allow oxygen to reach the zinc anode surface for reduction, and provides suitable hydrophobicity. If the ratio of the thickness of the polytetrafluoroethylene layer 200 to the thickness of the membrane body 100 is too large, the membrane body 100 will have a small proportion, resulting in a low electrolyte content within the body; conversely, if the ratio is too small, the polytetrafluoroethylene layer 200 will be relatively thin, making it difficult to guarantee its puncture resistance.

[0028] Specifically, the polytetrafluoroethylene (PTFE) layer 200 is formed by interwoven PTFE fibers, which are tightly interwoven on the surface of the separator body 100, forming a tough fibrous compound layer. During the winding process, this compound layer can significantly enhance the separator's puncture resistance and greatly reduce the possibility of battery short circuits and low voltage.

[0029] In one embodiment of this utility model, the diaphragm body 100 includes a base membrane 110, and the polytetrafluoroethylene layer 200 is disposed on the base membrane 110. The base membrane 110 serves as the basic structure of the diaphragm body 100, providing basic mechanical support for the entire diaphragm, while also adsorbing the electrolyte and firmly locking the electrolyte inside the base membrane 110.

[0030] like Figure 2As shown, in an alternative embodiment of this utility model, the separator body 100 includes a base membrane 110 and a functional coating 120, the functional coating 120 being disposed on both sides of the base membrane 110; at least one of the functional coatings 120 has a polytetrafluoroethylene layer 200 disposed on the side facing away from the base membrane 110. The base membrane 110 provides basic physical support and basic separator performance. The functional coating 120 can be designed according to the specific needs of the battery; for example, it can have good electrolyte affinity, allowing the electrolyte to better wet the separator, reduce resistance, and thus improve the charge and discharge efficiency of the battery. The polytetrafluoroethylene layer 200 is disposed on the side of the functional coating 120 facing away from the base membrane 110, which can both exert its puncture resistance and ion selective passage functions and work synergistically with the functional coating 120. Further, the functional coating 120 is... layer, layer, layer, One of the following: layer, PEDOT / PSS layer, MgO layer, graphene / carbon nanotube layer, polydopamine (PDA) layer, ceramic coating, artificial SEI layer, sulfide / oxide electrolyte layer.

[0031] In one embodiment of this utility model, the polytetrafluoroethylene (PTFE) layer 200 is hot-pressed onto the diaphragm body 100; or, the PTFE layer 200 is bonded to the diaphragm body 100; or, the PTFE layer 200 is formed by interlacing PTFE fibers sprayed onto the diaphragm body 100. During spraying, the nozzle pressure is 0.2~0.6 MPa; the spraying amount per unit area is 5~50 g / m².

[0032] In one embodiment of this utility model, the polytetrafluoroethylene layer 200 is disposed on one side of the separator body 100; or, the polytetrafluoroethylene layer 200 is disposed on both sides of the separator body 100. The specific design can be tailored to the specific requirements of the battery.

[0033] This utility model embodiment also provides a battery, including a positive electrode, a negative electrode, and a separator as described in any of the above embodiments, to possess all the effects of a separator. The separator is disposed between the positive electrode and the negative electrode.

[0034] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. A diaphragm, characterized by It includes a diaphragm body (100) and a polytetrafluoroethylene layer (200) disposed on at least one side of the diaphragm body (100), wherein the thickness of the polytetrafluoroethylene layer (200) is 0.01 mm to 0.10 mm; The diaphragm body (100) includes a base membrane (110) and a functional coating (120), the functional coating (120) being disposed on both sides of the base membrane (110); at least one of the functional coatings (120) having a polytetrafluoroethylene layer (200) disposed on the side opposite to the base membrane (110). The functional coating (120) is layer, layer, layer, One of the following: layer, PEDOT / PSS layer, MgO layer, graphene / carbon nanotube layer, polydopamine (PDA) layer, ceramic coating, artificial SEI layer, sulfide / oxide electrolyte layer.

2. The diaphragm according to claim 1, characterized in that, The ratio of the thickness of the polytetrafluoroethylene layer (200) to the thickness of the membrane body (100) is 1:(0.1~10).

3. The separator of claim 1, wherein The polytetrafluoroethylene layer (200) is formed by interlacing polytetrafluoroethylene fibers.

4. The diaphragm according to claim 1, characterized in that, The diaphragm body (100) includes a base membrane (110), and the polytetrafluoroethylene layer (200) is disposed on the base membrane (110).

5. The separator of claim 1, wherein The polytetrafluoroethylene layer (200) is hot-pressed onto the diaphragm body (100); or the polytetrafluoroethylene layer (200) is bonded to the diaphragm body (100); or the polytetrafluoroethylene layer (200) is formed by interlacing polytetrafluoroethylene fibers sprayed onto the diaphragm body (100).

6. The separator of claim 1, wherein The polytetrafluoroethylene layer (200) is disposed on one side of the diaphragm body (100); or, the polytetrafluoroethylene layer (200) is disposed on both sides of the diaphragm body (100).

7. A battery, characterized in that, It includes a positive electrode, a negative electrode, and a separator according to any one of claims 1 to 6, wherein the separator is disposed between the positive electrode and the negative electrode.

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