Selective diaphragm and battery using same
By designing a selective separator, the electric field is formed by connecting the composite separator to the DC power supply, the high capacity, high stability and long cycle life of the lithium-ion battery are achieved, and the low energy density per unit mass and the low cycle times of the lithium-ion battery are solved. The problem.
Patent Information
- Application Number
- CN202420509034.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-15
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-03-15
AI Technical Summary
The energy density per unit mass of lithium-ion batteries is not high, with safety and stability problems, and the number of cycles is low, making it difficult to meet the needs of high capacity and long cycle life.
A selective separator is designed, including a connection method between the composite separator and a DC power supply, forming an electric field, and there are conductive layers and micropores on the composite separator, which can selectively allow anions or cations to pass through, realize ion selection of the battery separator, and with The electrolyte solution is located between the positive electrode and the negative electrode.
By changing the charge type of composite separator, the ion selection of the battery separator is achieved, the production cost is reduced, and the capacity, stability and cycle life of the battery are improved.
Smart Images
Figure CN222300801U_ABST
Abstract
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 clean energy and the advancement of energy transformation, electrochemical energy storage technology has gradually become a key link in the regulation of power systems. Electrochemical energy storage is a technology that converts electrical energy into chemical energy through chemical reactions, and then converts chemical energy into electrical energy when needed. Common electrochemical energy storage devices include lithium-ion batteries, sodium-sulfur batteries, etc. Among them, lithium-ion battery technology mainly realizes the back-and-forth shuttle of lithium ions through the gain and loss of electrons of multivalent elements at the positive and negative electrodes to form a charge and discharge reaction. Lithium-ion battery technology is widely used in electric vehicles, mobile communications, energy storage and other fields. The application of lithium-ion batteries in energy storage batteries has the following shortcomings: (1) The unit mass energy density of lithium-ion battery technology is not high, generally at 250Wh / kg, which is difficult to meet the high capacity requirements of energy storage batteries; (2) During the charging reaction, dendrites will be generated when lithium ions undergo a reduction reaction, which will affect the safety and stability of lithium-ion batteries; (3) The number of cycles is low, about 800 times, which is difficult to meet the requirements of long cycle life of energy storage batteries.
[0003] Therefore, there is an urgent need to invent a new battery with high capacity, high stability and long cycle life and a separator used in the battery. Utility Model Content
[0004] In view of the problems existing in the prior art, the utility model provides a selective diaphragm, including a DC power supply and a composite diaphragm electrically connected to the positive electrode of the DC power supply to form an electric field around the composite diaphragm, wherein the composite diaphragm includes a macromolecular membrane and the composite diaphragm can be positively charged.
[0005] Furthermore, a conductive layer is compounded on the composite diaphragm.
[0006] Furthermore, the composite diaphragm is provided with a plurality of micropores for ions to pass through.
[0007] Furthermore, the thickness of the composite diaphragm is 0.05 mm to 0.07 mm.
[0008] Furthermore, the composite diaphragm is electrically connected to the positive electrode of a DC power supply, the negative electrode of the DC power supply is grounded, and the composite diaphragm is positively charged. At this time, the micropores of the composite diaphragm can allow anions to pass through.
[0009] Furthermore, the composite membrane is electrically connected to the negative electrode of a DC power supply, the positive electrode of the DC power supply is grounded, and the composite membrane is negatively charged. At this time, the micropores of the composite membrane can allow cations to pass through.
[0010] 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.
[0011] The utility model has reasonable design and has the following advantages:
[0012] (1) The selective diaphragm of the utility model can change the charge type of the composite diaphragm by changing the connection mode between the composite diaphragm and the DC power supply, so that ions with the same charge as the composite diaphragm adhere to the composite diaphragm, and ions with different charges pass through the battery diaphragm, thereby realizing ion selection of the battery diaphragm;
[0013] (2) The composite diaphragm of the utility model can conduct electricity by itself and can realize the function of a selective diaphragm by connecting to a DC power supply. It has a simple structure, reduces production costs, and has high economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] 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.
[0015] Figure 1 It is a structural schematic diagram of the selective diaphragm in the utility model;
[0016] In the figure: 1. composite diaphragm; 2. DC power supply. DETAILED DESCRIPTION
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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
[0021] The selective membrane in this embodiment is an anion membrane.
[0022] The selective diaphragm includes a composite diaphragm 1 and a DC power source 2 electrically connected to the composite diaphragm 1. The composite diaphragm 1 is connected to the positive electrode of the DC power source 2 to form an electric field around the composite diaphragm 1. The composite diaphragm includes a macromolecular membrane having a through-hole structure, which is a plurality of nano-scale micropores with a large specific surface area and a porosity between 20% and 80%, through which anions can pass.
[0023] The material of the composite diaphragm 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 composite diaphragm 1 can include a single polytetrafluoroethylene layer, a single polyethylene layer, a single polypropylene layer; it can also include two polytetrafluoroethylene layers, two polyethylene layers, two polypropylene layers, 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 composite diaphragm 1 is between 0.04mm and 0.18mm.
[0024] The composite diaphragm is composited with a conductive layer. The conductive layer can be a metal conductive layer, such as a copper conductive layer, a silver conductive layer, etc. The composite diaphragm 1 of the utility model has good adsorption, a 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 the negative electrode, and avoid forming a short circuit. The composite diaphragm can be positively charged.
[0025] In this embodiment, the DC power source 2 is a dry cell battery.
[0026] 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 composite diaphragm 1 and the negative electrode of the DC power supply 2 is grounded, the composite diaphragm 1 is positively charged, and the positive charge attached to the composite diaphragm 1 will attract the free anions in the electrolyte to move toward the composite diaphragm 1, and then pass through the micropores of the composite diaphragm 1. Example 2
[0027] The difference from Example 1 is that:
[0028] The composite membrane 1 is connected to the negative electrode of the DC power supply 2 to form an electric field around the composite membrane 1. The composite membrane includes a macromolecular membrane having a through-hole structure, which is a plurality of nano-scale micropores with a large specific surface area and a porosity between 20% and 80%, through which cations can pass.
[0029] 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 composite diaphragm 1 and the positive electrode of the DC power supply 2 is grounded, an electric field is formed at the composite diaphragm 1, and the composite diaphragm 1 is negatively charged. The negative charge attached to the composite diaphragm 1 will attract free cations in the electrolyte to move toward the composite diaphragm 1, and then pass through the micropores of the composite diaphragm 1.
[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 this 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 solution deviate from the scope of the technical solution of the embodiments of the utility model.
Claims
1. A selective diaphragm, characterized in that: The invention comprises a direct current power source and a composite diaphragm electrically connected to the positive electrode of the direct current power source, so as to form an electric field around the composite diaphragm, wherein the composite diaphragm comprises a macromolecular film, and the composite diaphragm can be positively charged.
2. A selective membrane according to claim 1, characterized in that: A conductive layer is compounded on the composite diaphragm.
3. A selective membrane according to claim 1, characterized in that: The composite diaphragm is provided with a plurality of micropores for ions to pass through.
4. A selective membrane according to claim 1, characterized in that: The thickness of the composite diaphragm is 0.05 mm to 0.07 mm.
5. A selective membrane according to claim 2, characterized in that: The composite diaphragm is electrically connected to the positive electrode of a DC power source, the negative electrode of the DC power source is grounded, and the composite diaphragm is positively charged. At this time, the micropores of the composite diaphragm can allow anions to pass through.
6. A selective membrane according to claim 2, characterized in that: The composite diaphragm is electrically connected to the negative electrode of the DC power supply, the positive electrode of the DC power supply is grounded, and the composite diaphragm is negatively charged. At this time, the micropores of the composite diaphragm can 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.