Selective diaphragm and battery using same

Abstract

The utility model relates to the technical field of inorganic electrochemical energy storage, in particular to a selective diaphragm and a battery applying the same, which comprise a diaphragm component and a direct current power supply electrically connected with the diaphragm component so as to form an electric field around the diaphragm component, and the diaphragm component comprises an insulating part and a conductive part positioned on one side of the insulating part and used for supporting the diaphragm. According to the selective diaphragm, the charge type of the diaphragm assembly can be changed by changing the connection mode of the diaphragm assembly and the direct-current power supply, so that ions transmitted by the diaphragm are selected. According to the utility model, the conductive part is arranged on the side edge of the insulating part, and the conductor of the conductive part can support and fix the insulating part and prevent the insulating part from deforming, so that the shrinkage of a diaphragm micropore is reduced, and the stability of ion penetration is ensured; meanwhile, the heat insulation effect of the conductive part is good, the insulating part can be protected, the problem that the insulating part is melted due to high temperature of the electrolyte solution when the battery works is solved, and the safety is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to a selective diaphragm and a battery using the diaphragm. Background Art

[0002] With the rapid development of electric vehicles, portable devices and power storage, people are increasingly demanding high-performance batteries. Common power batteries on the market include lithium-ion batteries, nickel-metal hydride batteries, fuel cells and lead-acid batteries, and energy storage batteries include flow batteries, sodium-sulfur batteries and fuel cells. These power batteries and energy storage batteries mainly use liquid electrolytes, which requires a diaphragm inside the battery.

[0003] Taking lithium-ion batteries as an example, the main function of the separator is to allow lithium ions to pass smoothly, while blocking the transmission of electrons inside the battery, isolating the contact between the positive and negative electrodes and causing short circuits. It is an important safety component of the battery. Existing lithium-ion battery separators include inorganic modified polyolefin separators, which use inorganic nanoparticles such as SiO 2 、TiO 2 、Al 2 O 3 and ZrO 2 After being treated, the modified membrane is coated on both sides of the polyolefin membrane. The modified membrane has good thermal stability and electrolyte wettability. However, due to the high surface energy, inorganic nanoparticles are prone to agglomeration. When inorganic nanoparticles are used to coat the membrane, it is easy to cause the pores of the membrane to be blocked and the porosity to be reduced. Moreover, most of the inorganic nanoparticles used for modification have poor conductivity. After modification, the membrane resistance increases, which seriously affects the electrochemical performance of the battery.

[0004] Therefore, there is an urgent need to invent a new selective diaphragm and a battery using the diaphragm. Utility Model Content

[0005] In view of the problems existing in the prior art, the utility model provides a selective diaphragm, including a diaphragm assembly and a DC power supply electrically connected to the diaphragm assembly to form an electric field around the diaphragm assembly, the diaphragm assembly includes an insulating part and a conductive part located on the side of the insulating part for supporting the diaphragm, the conductive part is made of a conductor material, and the insulating part is made of an insulating material.

[0006] Furthermore, the diaphragm is provided with a plurality of micropores, and the conductive part is provided with a plurality of basic pores, through which ions can pass.

[0007] Furthermore, the thickness of the insulating portion is 0.04 mm to 0.06 mm.

[0008] Furthermore, the thickness of the conductive part is 0.08 mm to 0.12 mm.

[0009] Furthermore, the conductive part of the diaphragm assembly is electrically connected to the positive electrode of the DC power supply, and the conductive part is positively charged. At this time, the micropores of the diaphragm assembly can allow anions to pass through.

[0010] Furthermore, the conductive part of the diaphragm assembly is electrically connected to the negative electrode of the DC power supply, and the conductive part is negatively charged. At this time, the micropores of the diaphragm assembly can allow cations to pass through.

[0011] The utility model also provides a battery, which comprises a positive electrode, a negative electrode, an electrolyte solution and a selective diaphragm, wherein the selective diaphragm and the electrolyte solution are located between the positive electrode and the negative electrode.

[0012] The utility model has reasonable design and has the following advantages:

[0013] (1) The selective diaphragm of the utility model can change the charge type of the diaphragm assembly by changing the connection mode between the diaphragm assembly and the DC power supply, thereby selecting the ions transmitted by the diaphragm, and has a simple structure;

[0014] (2) The utility model has a conductive part on one side of the insulating part. The conductor of the conductive part can not only support and fix the insulating part to prevent the insulating part from deformation, thereby reducing the shrinkage of the diaphragm micropores and the shrinkage rate, and ensuring the stability of ion penetration; at the same time, the conductive part has a good heat insulation effect, which can protect the insulating part and reduce the problem of melting of the insulating part due to high temperature of the electrolyte solution when the battery is working, thereby improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the structure of the selective diaphragm in the utility model;

[0017] In the figure: 1. diaphragm assembly; 11. insulating part; 12. conductive part; 2. DC power supply. DETAILED DESCRIPTION

[0018] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0019] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this description, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0020] The technical solution of the utility model will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] The utility model embodiment discloses a battery, comprising: a positive electrode, a negative electrode, a selective diaphragm and an electrolyte solution, wherein the selective diaphragm and the electrolyte solution are located between the positive electrode and the negative electrode. The selective diaphragm may be an anion diaphragm or a cation diaphragm. When the selective diaphragm is an anion diaphragm, only anions can pass through the selective diaphragm, and move between the positive and negative electrodes to form a current to achieve the storage and release of electric energy. When the selective diaphragm is a cation diaphragm, only cations can pass through the selective diaphragm, and move between the positive and negative electrodes to form a current to achieve the storage and release of electric energy. Example 1

[0022] The selective diaphragm includes a diaphragm assembly 1 and a DC power supply 2 electrically connected to the diaphragm assembly 1, the diaphragm assembly 1 includes an insulating portion 11 and a conductive portion 12 located on the side of the insulating portion 11 for supporting the diaphragm, the conductive portion 12 of the diaphragm assembly 1 is connected to the negative electrode of the DC power supply 2 to form an electric field around the diaphragm assembly 1.

[0023] The material of the insulating part 11 can be polytetrafluoroethylene material or polyethylene and other materials. Of course, other insulating materials such as polypropylene are also within the protection scope of the present utility model. In other embodiments, the insulating part 11 can include a single layer of polytetrafluoroethylene, a single layer of polyethylene, or a single layer of polypropylene; it can also include two layers of polytetrafluoroethylene, two layers of polyethylene, two layers of polypropylene, or a composite layer of the three or any two of them; in the embodiment of the aforementioned composite layer, the polytetrafluoroethylene layer, the polyethylene layer, and the polypropylene layer can be overlapped. The thickness of the aforementioned insulating part 11 is between 0.04 mm and 0.06 mm.

[0024] The insulating part 11 is provided with a plurality of tiny micropores, and the porosity thereof is between 20% and 80%, which can allow cations to pass through. The insulating part 11 of the utility model has good adsorption, high melting point, and good insulation, and can isolate the positive and negative electrodes of the battery, prevent the positive electrode of the battery from contacting with the negative electrode, and avoid forming a short circuit.

[0025] In this embodiment, the DC power supply 2 is a dry cell. The conductive part 12 is a conductor material, specifically steel, or other hard conductive materials. In this embodiment, the conductive part 12 is a steel plate, and the thickness of the steel plate is between 0.08 mm and 0.12 mm. The number of the conductive parts 12 can be one or two. The number of the conductive parts 12 is 1, which is located on one side of the insulating part 11. The conductive part 12 is provided with a plurality of base holes. The base holes on the conductive part 12 and the micropores on the insulating part 11 can be arranged correspondingly or crosswise, so as to facilitate the cations in the electrolyte solution to pass through the diaphragm assembly 1. The conductive part 12 of the utility model is used to support and fix the insulating part 11 to prevent the insulating part 11 from deforming, so as to reduce the shrinkage of the diaphragm micropores, reduce the shrinkage rate, and ensure the stability of ion penetration; at the same time, the conductive part 12 has a good heat insulation effect, which can protect the insulating part 11 and reduce the problem of melting of the insulating part 11 when the electrolyte solution temperature is high when the battery is working.

[0026] The working principle of the selective diaphragm in this embodiment is: when the negative electrode of the DC power supply 2 is electrically connected to the conductive part 12 of the diaphragm assembly 1, and the positive electrode of the DC power supply 2 is grounded, the conductive part 12 is negatively charged, and the negative charge attached to the diaphragm assembly 1 will attract the free cations in the electrolyte to move toward the diaphragm assembly 1, and then pass through the micropores of the insulating part 11. Example 2

[0027] The difference from Example 1 is that:

[0028] The conductive part 12 of the diaphragm assembly 1 is connected to the positive electrode of the DC power supply 2 to form an electric field around the diaphragm assembly 1. The insulating part 11 is provided with a plurality of fine micropores, the porosity of which is between 20% and 80%, through which anions can pass.

[0029] The working principle of the selective diaphragm in this embodiment is: when the positive electrode of the DC power supply 2 is electrically connected to the conductive part 12 of the diaphragm assembly 1, and the negative electrode of the DC power supply 2 is grounded, an electric field is formed at the diaphragm assembly 1, and the conductive part 12 is positively charged. The positive charge attached to the diaphragm assembly 1 will attract the free anions in the electrolyte to move toward the diaphragm assembly 1, and then pass through the micropores of the insulating part 11.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A selective diaphragm, characterized in that: The invention comprises a diaphragm assembly (1) and a direct current power source (2) electrically connected to the diaphragm assembly (1) so as to form an electric field around the diaphragm assembly (1); the diaphragm assembly (1) comprises an insulating portion (11) and a conductive portion (12) located on one side of the insulating portion (11) and used for supporting the diaphragm.

2. A selective membrane according to claim 1, characterized in that: The diaphragm is provided with a plurality of micropores, and the conductive part (12) is provided with a plurality of basic pores for ions to pass through.

3. A selective membrane according to claim 1, characterized in that: The thickness of the insulating part (11) is 0.04 mm to 0.06 mm.

4. A selective membrane according to claim 1, characterized in that: The thickness of the conductive part (12) is 0.08 mm to 0.12 mm.

5. A selective membrane according to claim 2, characterized in that: The conductive part (12) of the diaphragm assembly (1) is electrically connected to the positive electrode of a DC power supply (2), the negative electrode of the DC power supply is grounded, and the conductive part (12) is positively charged. At this time, the micropores of the diaphragm assembly (1) allow anions to pass through.

6. A selective membrane according to claim 2, characterized in that: The conductive part (12) of the diaphragm assembly (1) is electrically connected to the negative electrode of the DC power supply (2), the positive electrode of the DC power supply is grounded, and the conductive part (12) is negatively charged. At this time, the micropores of the diaphragm assembly (1) allow cations to pass through.

7. A battery, characterized in that: The invention comprises a positive electrode, a negative electrode, an electrolyte solution and the selective separator according to any one of claims 1 to 6, wherein the selective separator and the electrolyte solution are located between the positive electrode and the negative electrode.

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