Lithium metal button batteries and their assembly methods

Abstract

This application relates to the field of battery technology and discloses a lithium metal coin cell battery and its assembly method. The lithium metal coin cell battery includes a casing and a battery assembly; the casing includes a positive electrode casing and a negative electrode casing, with the negative electrode casing covering the positive electrode casing, and the negative and positive electrode casings forming a closed accommodating space; the battery assembly is located within the accommodating space and includes a positive electrode sheet, a separator, a lithium metal sheet, nickel foam, and a corrugated spring sheet. The positive electrode sheet, separator, lithium metal sheet, nickel foam, and corrugated spring sheet are stacked sequentially along the direction from the positive electrode casing to the negative electrode casing, with the positive electrode sheet abutting against the positive electrode casing and the corrugated spring sheet abutting against the negative electrode casing. The lithium metal coin cell battery disclosed in this application can improve the battery yield.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a lithium metal button battery and its assembly method. Background Technology

[0002] Lithium metal coin cells are frequently used for the development of new electrode materials and the verification of electrochemical performance due to their advantages such as small size, low cost, and simple assembly. A typical lithium metal coin cell usually consists of a positive electrode shell, a negative electrode shell, and a lithium metal sheet. During battery assembly, a spacer or nickel foam is usually placed between the lithium metal sheet and the negative electrode shell to support and position the lithium metal sheet.

[0003] However, the lithium metal sheet and the gasket are prone to slippage, resulting in poor alignment. This can cause the lithium metal sheet to be crushed after battery encapsulation, leading to a short circuit. Furthermore, nickel foam only provides internal filling; the internal pressure, i.e., the tightness of the positive and negative electrode contact, often falls short of requirements. For positive electrode materials with gas-generating properties, the gas produced during cycling often cannot be expelled in time and accumulates in the central area of ​​the electrode, causing a reduction in battery capacity. Summary of the Invention

[0004] This application provides a lithium metal button battery and its assembly method to solve the problem of low battery yield caused by short circuits and insufficient internal pressure during battery assembly.

[0005] In a first aspect, this application provides a lithium metal button battery, including a casing and a battery assembly;

[0006] The housing includes a positive electrode housing and a negative electrode housing, the negative electrode housing covers the positive electrode housing, and the negative electrode housing and the positive electrode housing cooperate to form a closed accommodating space;

[0007] The battery assembly is located within the accommodating space. The battery assembly includes a positive electrode, a separator, a lithium metal sheet, nickel foam, and a corrugated spring sheet. The positive electrode, separator, lithium metal sheet, nickel foam, and corrugated spring sheet are stacked sequentially along the direction from the positive electrode shell to the negative electrode shell, and the positive electrode abuts against the positive electrode shell, and the corrugated spring sheet abuts against the negative electrode shell.

[0008] The lithium metal coin cell of this application incorporates nickel foam. During battery assembly, the rough nickel foam ensures tight contact with the lithium metal sheet, preventing relative slippage between them and thus avoiding short circuits. The use of corrugated spring contacts effectively increases internal battery pressure, resulting in tighter contact between the positive and negative electrodes. Simultaneously, gases produced during cycling are smoothly expelled from the electrode center under internal pressure, preventing air bubbles from hindering cycling and improving battery capacity. Furthermore, the large contact area between the corrugated spring contacts and the nickel foam prevents damage to the nickel foam. Therefore, the lithium metal coin cell of this application, by incorporating nickel foam and corrugated spring contacts, effectively improves battery yield.

[0009] In some possible implementations, the diameter of the nickel foam is less than or equal to the diameter of the lithium metal sheet.

[0010] In some possible implementations, the nickel foam is coaxially arranged with the lithium metal sheet.

[0011] In some possible implementations, the wave-shaped spring includes a spring body with a plurality of spaced protrusions on the side of the spring body facing the negative electrode shell.

[0012] In some possible implementations, the diameter of the corrugated spring is less than or equal to the diameter of the nickel foam.

[0013] In some possible implementations, the corrugated sheet is coaxially arranged with the nickel foam.

[0014] In some possible implementations, the positive electrode, the separator, the lithium metal sheet, the nickel foam, and the corrugated spring sheet are arranged coaxially.

[0015] Secondly, this application provides a method for assembling a lithium metal button battery, the lithium metal button battery comprising a positive electrode shell, a negative electrode shell, a separator, a lithium metal sheet, nickel foam, and a corrugated spring sheet, the assembly method comprising:

[0016] Lay the positive electrode shell flat;

[0017] The positive electrode sheet is placed inside the positive electrode shell;

[0018] The diaphragm is used to cover the surface of the positive electrode sheet;

[0019] Electrolyte is dropped onto the diaphragm to wet it and remove small air bubbles between the diaphragm and the positive electrode.

[0020] The lithium metal sheet is placed on the side of the separator away from the positive electrode sheet;

[0021] The nickel foam is placed on the side of the lithium metal sheet opposite to the diaphragm;

[0022] The wavy elastic sheet is placed on the side of the nickel foam that is away from the lithium metal sheet;

[0023] The negative electrode shell is placed over the positive electrode shell, and the opening between the positive electrode shell and the negative electrode shell is sealed.

[0024] The lithium metal button cell assembly method described in this application, by placing foamed nickel and corrugated springs on a lithium metal sheet, not only solves the problem of battery short circuits but also addresses the low battery yield caused by insufficient internal pressure. Furthermore, the assembly method in this application is simple, reduces assembly time, and improves operational efficiency. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of an exploded structure of a lithium metal button battery in an embodiment of this application;

[0026] Figure 2 for Figure 1 A schematic diagram of an overall structure of a lithium metal button cell;

[0027] Figure 3 for Figure 1 A schematic diagram of a type of wave-shaped spring.

[0028] In the picture:

[0029] 1-Lithium metal button cell battery; 10-Casing; 11-Positive electrode casing; 111-First base plate; 112-First side plate; 12-Negative electrode casing; 121-Second base plate; 122-Second side plate; 20-Positive electrode sheet; 30-Separator; 40-Lithium metal sheet; 50-Foamed nickel; 60-Wave-shaped spring sheet; 61-Spring sheet body; 62-Protrusion. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] refer to Figure 1 and Figure 2The lithium metal button battery 1 in this embodiment may include a casing 10 and a battery assembly, and the lithium metal button battery 1 may be button-shaped overall. The casing 10 may include a positive electrode casing 11 and a negative electrode casing 12. The positive electrode casing 11 may include a first bottom plate 111 and a first side plate 112. The first side plate 112 is connected to the first bottom plate 111, and the first side plate 112 and the first bottom plate 111 may cooperate to form a space with a first opening on one side. The negative electrode casing 12 may include a second bottom plate 121 and a second side plate 122. The second side plate 122 is connected to the side of the second side plate 122 facing the positive electrode casing 11, and the second side plate 122 and the second bottom plate 121 may cooperate to form a space with a second opening on one side.

[0032] In this embodiment, the negative electrode shell 12 can be closed with the positive electrode shell 11 to form an accommodating space for accommodating the battery assembly. Specifically, the second opening of the negative electrode shell 12 can be opposite to the first opening of the positive electrode shell 11, and the diameter of the second bottom plate 121 can be smaller than the diameter of the first bottom plate 111. When the negative electrode shell 12 is closed with the positive electrode shell 11, the second side plate 122 can extend into the positive electrode shell 11 and fit tightly against the first side plate 112, thereby allowing the positive electrode shell 11 and the negative electrode shell 12 to cooperate to form a closed space.

[0033] The battery assembly may include a positive electrode 20, a separator 30, a lithium metal sheet 40, nickel foam 50, and a corrugated spring sheet 60 stacked sequentially. The positive electrode 20 can be fixed to the first base plate 111 of the positive electrode shell 11, and the corrugated spring sheet 60 can abut against the second base plate 121 of the negative electrode shell 12. It is understood that in this embodiment, when nickel foam 50 is used instead of a gasket, during battery assembly, the larger surface roughness of the nickel foam 50 allows it to effectively contact the lithium metal sheet 40, thus effectively preventing relative sliding between the nickel foam 50 and the lithium metal sheet 40, protecting the lithium metal sheet 40 from damage and preventing a short circuit in the battery.

[0034] In some embodiments, the diameter of the nickel foam 50 can be the same as the diameter of the lithium metal sheet 40. This increases the contact area between the nickel foam 50 and the lithium metal sheet 40, thereby more effectively preventing relative sliding between them. Of course, in other embodiments, provided that there is sufficient contact area between the nickel foam 50 and the lithium metal sheet 40, the diameter of the nickel foam 50 can be slightly smaller than the diameter of the lithium metal sheet 40.

[0035] Further, refer to Figure 3The wavy spring 60 can be in the form of a circular ring. Specifically, the wavy spring 60 may include a spring body 61, which has multiple protrusions 62 spaced apart to make the spring body wavy. When the wavy spring 60 is placed on the nickel foam 50, the spring body 61 can contact the nickel foam 50, and its protrusions 62 can face the negative electrode shell 12. When the negative electrode shell 12 is closed with the positive electrode shell 11, the second bottom plate 121 abuts against the protrusions 62, thereby applying pressure to the protrusions 62.

[0036] It should be understood that, in this embodiment, by setting the corrugated spring 60, when the corrugated spring 60 is subjected to pressure, due to the stacking of the structural components, the corrugated spring 60 can transmit pressure to the nickel foam 50, thereby effectively increasing the internal pressure of the battery and making the positive and negative electrodes more tightly connected. At the same time, the gas produced by the battery during cycling can also be smoothly discharged from the middle of the electrode under the internal pressure of the battery, thereby preventing the motor area from being unable to effectively participate in battery cycling due to air bubbles. In addition, compared with the more conventional funnel-shaped spring, the corrugated spring 60 in this embodiment can also increase the force-bearing area between the spring and the nickel foam 50, thereby avoiding damage to the nickel foam 50.

[0037] In this embodiment, the outer diameter of the corrugated spring 60 can be the same as the diameter of the nickel foam 50. This allows the pressure exerted on the nickel foam 50 by the corrugated spring 60 to be more uniform, thereby more effectively increasing the internal pressure of the battery. Of course, in some other embodiments, provided that the corrugated spring 60 exerts sufficient pressure on the nickel foam 50, the outer diameter of the corrugated spring 60 can be slightly smaller than the diameter of the nickel foam 50.

[0038] In addition, the positive electrode 20, separator 30, lithium metal sheet 40, nickel foam 50 and corrugated spring sheet 60 can all be coaxially arranged with the positive electrode shell 11, that is, each structural component in the above battery assembly is centered and aligned with the positive electrode shell 11, thereby ensuring good battery performance.

[0039] After a detailed description of the lithium metal button battery 1 in this embodiment, the assembly method of the lithium metal button battery 1 will be specifically explained below.

[0040] The assembly method of the lithium metal button battery 1 in this embodiment may include the following steps:

[0041] Step S100: First place the positive electrode shell 11 and flatten it;

[0042] Step S200: Place the positive electrode plate 20 inside the positive electrode shell 11 and set the positive electrode plate 20 and the positive electrode shell 11 coaxially;

[0043] Step S300: Cover the surface of the positive electrode 20 with the separator 30, and set the separator 30 and the positive electrode 20 coaxially;

[0044] Step S400: Add an appropriate amount of electrolyte to the diaphragm 30 to wet the diaphragm 30 and remove small air bubbles between the diaphragm 30 and the positive electrode plate 20.

[0045] Step S500: Place the lithium metal sheet 40 on the side of the separator 30 away from the positive electrode 20, and set the lithium metal sheet 40 and the separator 30 coaxially.

[0046] Step S600: Place the nickel foam 50 on the side of the lithium metal sheet 40 away from the separator 30, and set the nickel foam 50 and the lithium metal sheet 40 coaxially.

[0047] Step S700: Place the wavy spring 60 on the side of the nickel foam 50 away from the lithium metal sheet 40, and set the wavy spring 60 and the nickel foam 50 coaxially.

[0048] Step S800: Cover the negative electrode shell 12 onto the positive electrode shell 11 and seal the lithium metal button cell 1.

[0049] It should be noted that in the above steps, in steps S200, S300 and S500, when placing the positive electrode 20, the separator 30 and the nickel foam 50 respectively, tweezers can be used to pick up the positive electrode 20, the separator 30 or the nickel foam 50 for placement, so as to protect the structure of the positive electrode 20, the separator 30 and the nickel foam 50.

[0050] It should be noted that the assembly method of the lithium metal button battery 1 in this embodiment is only an example. The assembly method in this embodiment is to assemble from the positive electrode shell 11 to the negative electrode shell 12. In actual application, it can also be assembled from the negative electrode shell 12 to the positive electrode shell 11.

[0051] The lithium metal coin cell and its assembly method disclosed in this application incorporate nickel foam and corrugated springs. During battery assembly, the nickel foam achieves tight contact with the lithium metal sheet, preventing relative sliding between them. The corrugated springs effectively increase the internal pressure of the battery, resulting in tighter contact between the positive and negative electrodes. Furthermore, gases produced during cycling can be smoothly expelled from the center of the electrodes under the internal pressure, preventing air bubbles in certain electrode areas from hindering battery cycling. The large contact area between the corrugated springs and the nickel foam also prevents damage to the nickel foam. Therefore, the lithium metal coin cell and its assembly method disclosed in this application can improve battery yield.

[0052] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A lithium metal button battery (1), characterized in that, Includes a housing (10) and a battery assembly; The housing (10) includes a positive electrode housing (11) and a negative electrode housing (12), the negative electrode housing (12) covers the positive electrode housing (11), and the negative electrode housing (12) and the positive electrode housing (11) cooperate to form a closed accommodating space; The battery assembly is located within the accommodating space. The battery assembly includes a positive electrode plate (20), a separator (30), a lithium metal sheet (40), a nickel foam (50), and a corrugated spring sheet (60). The positive electrode plate (20), separator (30), lithium metal sheet (40), nickel foam (50), and corrugated spring sheet (60) are stacked sequentially along the direction from the positive electrode shell (11) to the negative electrode shell (12). The positive electrode plate (20) abuts against the positive electrode shell (11), and the corrugated spring sheet (60) abuts against the negative electrode shell (12). The wave-shaped spring (60) includes a ring-shaped spring body (61), and the spring body (61) has a plurality of spaced protrusions (62) on the side facing the negative electrode shell (12). The upper surface of the foamed nickel (50) abuts against the lower surface of the spring body (61) of the wave-shaped spring (60) in a surface contact manner; when the negative electrode shell (12) covers the positive electrode shell (11), the protrusion (62) abuts against the negative electrode shell (12) and forms a gap between adjacent protrusions (62) that allows gas to be discharged from the center region of the battery to the edge.

2. The lithium metal button battery (1) according to claim 1, characterized in that, The diameter of the nickel foam (50) is less than or equal to the diameter of the lithium metal sheet (40).

3. The lithium metal button battery (1) according to claim 2, characterized in that, The nickel foam (50) and the lithium metal sheet (40) are arranged coaxially.

4. The lithium metal button battery (1) according to claim 1, characterized in that, The diameter of the wavy elastic piece (60) is less than or equal to the diameter of the nickel foam (50).

5. The lithium metal button battery (1) according to claim 4, characterized in that, The wavy elastic piece (60) is coaxially arranged with the nickel foam (50).

6. The lithium metal button battery (1) according to any one of claims 1 to 5, characterized in that, The positive electrode (20), the separator (30), the lithium metal sheet (40), the nickel foam (50), and the corrugated spring sheet (60) are arranged coaxially.

7. A method for assembling a lithium metal button battery, the lithium metal button battery comprising a positive electrode shell, a negative electrode shell, a separator, a lithium metal sheet, nickel foam, and a corrugated spring sheet, characterized in that, The assembly method includes: Lay the positive electrode shell flat; The positive electrode sheet is placed inside the positive electrode shell; The diaphragm is used to cover the surface of the positive electrode sheet; Electrolyte is dropped onto the diaphragm to wet it and remove small air bubbles between the diaphragm and the positive electrode. The lithium metal sheet is placed on the side of the separator away from the positive electrode sheet; The nickel foam is placed on the side of the lithium metal sheet opposite to the diaphragm; The wavy spring is placed on the side of the nickel foam away from the lithium metal sheet; the wavy spring includes a ring-shaped spring body, and the side of the spring body facing the negative electrode shell is provided with a plurality of spaced protrusions; the upper surface of the nickel foam and the lower surface of the spring body of the wavy spring are in surface contact. The negative electrode shell is placed over the positive electrode shell, and the positive electrode shell and the negative electrode shell are sealed together; wherein, when the negative electrode shell and the positive electrode shell are closed, the protrusion abuts against the negative electrode shell, and a gap is formed between adjacent protrusions to allow gas to escape from the center region of the battery to the edge.

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