Button cell battery

Abstract

The present invention discloses a button battery. The button battery of the present invention includes a case 10, a positive electrode powder layer 400, and a current collector 300. The case 10 includes a positive electrode case 100 and a negative electrode case 200 connected to each other. The positive electrode case 100 and the negative electrode case 200 are surrounded to form a cavity 101. The positive electrode powder layer 400 is disposed in the cavity 101. The current collector 300 is disposed in the cavity 101, and the current collector 300 and the positive electrode powder layer 400 are laminated, at least a part of the current collector 300 is embedded in the positive electrode powder layer 400, and the surface of the current collector 300 away from the positive electrode powder layer 400 is disposed so as to abut against the bottom surface of the positive electrode case 100.

Description

[Technical field]

[0001] This application claims priority to a Chinese patent application with application number 202320122324.7 filed with the China Patent Office on February 6, 2023, the entire contents of which are incorporated herein by reference. The present application relates to the technical field of batteries, for example button batteries. [Background technology]

[0002] The main components of a lithium manganese dioxide battery are the negative electrode case, the negative electrode, the separator, the positive electrode (including the positive electrode ring), the positive electrode case, and the electrolyte. The limited internal space of the battery cell limits the space occupied by the positive and negative electrodes, which in turn limits the capacity of the cell, and therefore its lifespan.

[0003] At present, most lithium manganese button battery cells adopt a structure in which a positive electrode ring encases a positive electrode powder layer, which results in a relatively large space occupied by the positive electrode ring and a limited space for arranging the positive and negative electrodes, resulting in a relatively small capacity of the battery cell and a relatively short service life.

[0004] Therefore, there is a need for button batteries that can solve these problems. Summary of the Invention [Problem to be solved by the invention]

[0005] The present application provides a button battery having a large battery cell capacity and a long life. [Means for solving the problem]

[0006] In a first aspect, an embodiment of the present application provides a button battery, the button battery including a case, a positive electrode powder layer, and a current collector, the case including a positive electrode case and a negative electrode case connected to each other, the positive electrode case and the negative electrode case are enclosed to form a cavity, the positive electrode powder layer is disposed in the cavity, the current collector is disposed in the cavity, the current collector and the positive electrode powder layer are disposed in a stacked manner, at least a portion of the current collector is embedded in the positive electrode powder layer, and the surface of the current collector away from the positive electrode powder layer is disposed to abut against the bottom surface of the positive electrode case.

[0007] In one embodiment, the current collector is a network structure.

[0008] In one embodiment, the surface of the current collector that is embedded in the positive electrode powder layer is a frosted surface or a surface that has burrs.

[0009] In one embodiment, the height to which the current collector is embedded in the positive electrode powder layer is 50% to 95% of the total height of the current collector.

[0010] In one embodiment, the current collector includes a plurality of cross-arranged collector bars, the plurality of collector bars being formed in a mesh-like structure, and a thickness of the cross-section of the plurality of collector bars being greater than a thickness of the collector bars.

[0011] In one embodiment, the material of the current collector is nickel, aluminum or stainless steel.

[0012] In one embodiment, the compaction density of the positive electrode powder layer is 2.0 to 3.0 g / mm 3 It is.

[0013] In one embodiment, the cross sections of the current collector and the positive electrode powder layer are circular, and the ratio of the cross-sectional diameters of the current collector and the positive electrode powder layer is 1:1 to 1:1.5.

[0014] In one embodiment, the mesh of the current collector is rhomboidal, and the ratio of the length a of the short diagonal of the rhomboid to the length b of the long diagonal is 1:1 to 1:3.

[0015] In one embodiment, the surface of the positive electrode powder layer in contact with the current collector and the longitudinal cross section of the current collector are both wavy, or the surface of the positive electrode powder layer in contact with the current collector and the longitudinal cross section of the current collector are both zigzag. Effect of the Invention

[0016] In the button battery according to the present invention, a cavity is formed by assembling the positive electrode case and the negative electrode case to accommodate the positive electrode powder layer and the current collector. By embedding at least a part of the current collector in the positive electrode powder layer, the space occupied by the current collector in the case can be reduced, and the volume of the positive electrode powder layer can be appropriately increased, which can further increase the battery cell capacity and extend the battery life. [Brief description of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view of a button battery according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of the structure of a roll-shaped current collector according to the first embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic diagram of the structure of a current collector according to the first embodiment of the present invention. [Figure 4] FIG. 2 is an exploded schematic view of a current collector and a positive electrode powder layer according to the first embodiment of the present invention. [Diagram 5] FIG. 11 is a schematic diagram of an assembly structure of a current collector and a positive electrode powder layer according to Example 3 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] In the description of this application, it is necessary to explain that the orientation or positional relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., is merely for the purpose of facilitating and simplifying the description of this application, and does not indicate or imply that it must have a specific orientation, be configured or operate in a specific orientation, but is based on the orientation or positional relationship shown in the drawings, and therefore cannot be understood as limiting this application. Furthermore, the terms "first" and "second" are used merely for the purpose of explanation, and are not understood to indicate or imply any relative importance. The terms "first position" and "second position" are two different positions, and the first feature being "above", "on" and "above" the second feature includes the first feature being directly above and diagonally above the second feature, or simply the horizontal height of the first feature being higher than the horizontal height of the second feature. A first feature being "below," "under," and "below" a second feature includes the first feature being directly below and diagonally below the second feature, or simply indicates that the horizontal height of the first feature is less than the horizontal height of the second feature.

[0019] In the description of this application, it should be clarified that the terms "attached", "connected" and "connection" should be generally understood unless otherwise clearly specified and limited. For example, it can be a fixed connection, a removable connection, or an integral connection. It can be mechanically or electrically connected. It can be directly connected, indirectly connected through an intermediate medium, and the insides of two parts can communicate with each other. Those skilled in the art can understand the meaning of the above terms in this application according to the situation.

[0020] The following describes the embodiments of the present specification shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements, or elements having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and are only used to describe the present application, and cannot be understood as limiting the present application.

[0021] [Example 1] 1 and 2, the button battery provided in this embodiment includes a case 10, a positive electrode powder layer 400, and a current collector 300. The case 10 includes a positive electrode case 100 and a negative electrode case 200 connected to each other. The positive electrode case 100 and the negative electrode case 200 are surrounded to form a cavity 101. The positive electrode powder layer 400 is disposed in the cavity 101. The current collector 300 is disposed in the cavity 101, and the current collector 300 and the positive electrode powder layer 400 are laminated, at least a portion of the current collector 300 is embedded in the positive electrode powder layer 400, and the surface of the current collector 300 away from the positive electrode powder layer 400 is disposed so as to abut against the bottom surface of the positive electrode case 100.

[0022] In the button battery, a cavity 101 for accommodating a positive electrode powder layer 400 and a current collector 300 is formed by assembling a positive electrode case 100 and a negative electrode case 200. By embedding at least a part of the current collector 300 in the positive electrode powder layer 400, the current collector 300 occupies a relatively small space in the case 10 compared to the installation of a positive electrode ring, so that the volume of the positive electrode powder layer can be appropriately increased, and the battery cell capacity can be further increased and the battery life can be extended.

[0023] Continuing to refer to FIG. 1, a positive electrode case 100 and a negative electrode case 200 are vertically engaged and connected, and inside the case 10, a current collector 300, a positive electrode powder layer 400, a separator 500, and a negative electrode sheet 600 are layered in this order from the top.

[0024] 2 and 3, optionally, the current collector 300 has a mesh structure. Optionally, the current collector 300 has an integrally molded mesh structure. The mesh structure of the current collector 300 makes it easy to embed the current collector 300 in the positive electrode powder layer 400, and also helps to press the current collector 300 and the positive electrode powder layer 400 together, so that the connection between them is stronger. Optionally, in this embodiment, the raw material of the current collector 300 is in a roll, and before the button battery is assembled, the rolled current collector 700 needs to be developed on a plane and punched into a circular sheet-shaped current collector 300 using an automatic punching machine.

[0025] Depending on the characteristics of the positive electrode powder layer 400, the surface of the current collector 300 embedded in the positive electrode powder layer 400 can be a frosted surface or a surface with burrs, thereby increasing the bonding strength between the current collector 300 and the positive electrode powder layer 400 and preventing the two from separating.

[0026] The height of the current collector 300 embedded in the positive electrode powder layer 400 is 50 to 95% of the total height of the current collector 300, and may be, for example, 50%, 60%, 80%, or 95%. The height of the current collector 300 embedded in the positive electrode powder layer 400 may be set according to parameters such as the thickness of the positive electrode powder layer 400 and the size of the cavity 101, and is not limited here. By embedding a part of the current collector 300 in the positive electrode powder layer 400, the space occupied by the current collector 300 in the cavity 101 can be reduced, the volume of the positive electrode powder layer 400 can be appropriately increased, and the battery cell capacity can be improved and the battery life can be extended.

[0027] The current collector 300 includes a plurality of cross-arranged current collector bars 310, which are formed in a net-like structure, and the thickness of the intersection 320 of the plurality of current collector bars is greater than the thickness of the current collector bar 310. In this embodiment, the thickness of the intersection 320 of the current collector bars may be 1.2 to 1.5 times, for example, 1.2 times, 1.3 times, 1.4 times, 1.5 times, etc., the thickness of the current collector bar 310. By increasing the thickness of the intersection 320 of the current collector bars, the structural strength of the current collector 300 can be increased, and the current collector 300 can be prevented from being damaged during assembly or use.

[0028] The mesh of the current collector 300 is rhombic, and the ratio of the length a of the long diagonal line of the rhombic shape to the length b of the short diagonal line is 1:1 to 1:3, and may be, for example, 1:1, 1:2, 1:3, or other ratios, which may be selected according to the battery model. By providing the mesh, the current collector 300 can be easily pressed into the positive electrode powder layer 400, and the difficulty of processing can be reduced.

[0029] The material of the current collector 300 is nickel, aluminum, or stainless steel, and the selection of the material of the current collector 300 affects the pulse capability of the battery cell. The current collector 300 using nickel or aluminum has a relatively strong expressive capability in terms of large current pulse.

[0030] The positive electrode powder layer 400 is mostly made of manganese powder, and in order to better bond the current collector 300, the compaction density of the positive electrode powder layer 400 is 2.0 to 3.0 g / mm 3 For example, 2.0 g / mm 3 , 2.5g / mm 3 , 3.0g / mm 3 or may be some other value.

[0031] The cross sections of the current collector 300 and the positive electrode powder layer 400 are both circular, and the ratio of the cross-sectional diameters of the current collector 300 and the positive electrode powder layer 400 is 1:1 to 1:1.5, for example, it may be 1:1, 1:1.2, 1:1.5, or other ratios. The current collector 300 and the positive electrode powder layer 400 may be arranged concentrically, and the cross-sectional area of ​​the current collector 300 is smaller than that of the positive electrode powder layer 400, thereby ensuring that the current collector 300 can be embedded in the positive electrode powder layer 400.

[0032] The assembly process of the button battery in this embodiment is as follows.

[0033] 4, a positive electrode is produced by pressing and embedding a current collector 300 into a positive electrode powder layer 400 using a press. A negative electrode sheet 600 is loaded into a negative electrode case 200, a cut separator 500 is placed on the negative electrode sheet 600, an electrolyte is dripped onto the separator 500, and after dripping is completed, the positive electrode powder layer 400 is placed on the separator 500, and the positive electrode case 100 is engaged with the negative electrode case 200 to package a sealed battery.

[0034] [Example 2] The structure of the button battery provided in this embodiment is the same as that in the first embodiment, and the difference between the two is the assembly process of the battery, which will be described below.

[0035] The negative electrode sheet 600 is loaded into the negative electrode case 200, the cut separator 500 is placed on top of the negative electrode sheet 600, the electrolyte is dripped onto the separator 500, and after the dripping is completed, the positive electrode powder layer 400 is placed on the separator 500, the current collector 300 is placed on the positive electrode powder layer 400, the positive electrode case 100 and the negative electrode case 200 are sealed and engaged, and the current collector 300 is embedded in the positive electrode powder layer 400 by the pressure generated after the positive electrode case 100 and the negative electrode case 200 are engaged.

[0036] [Example 3] The button battery provided in this embodiment is the same as that in the first embodiment, except for the assembly process of the battery, which will be described below.

[0037] 5, the current collector 300 is pressed and embedded in the positive electrode powder layer 400 by a press machine to form a positive electrode. The die for pressing the current collector 300 and the positive electrode powder layer 400 by the press machine is wavy or zigzag, so that the surface of the positive electrode powder layer 400 that contacts the current collector 300 and the longitudinal section of the current collector 300 are both wavy, or the surface of the positive electrode powder layer 400 that contacts the current collector 300 and the longitudinal section of the current collector 300 are both zigzag. By using a wavy or zigzag die, the bonding force between the current collector 300 and the positive electrode powder layer 400 can be increased to prevent the two from being separated from each other. The negative electrode sheet 600 is loaded into the negative electrode case 200, the cut separator 500 is placed on top of the negative electrode sheet 600, the electrolyte is dripped onto the separator 500, and after the dripping is completed, the positive electrode powder layer 400 is placed on the separator 500, and the positive electrode case 100 is engaged with the negative electrode case 200 to package a sealed battery. [Explanation of symbols]

[0038] 10: Case 101: Cavity 100: Positive electrode case 200: Negative electrode case 300: Current collector 310: Current collector bar 320: Intersection of current collector bar 400: Positive electrode powder layer 500:Separator 600: Negative electrode sheet 700: Rolled current collector

Claims

1. A button battery, The battery includes a case (10), a positive electrode powder layer (400), and a current collector (300), The case (10) includes a positive electrode case (100) and a negative electrode case (200) connected to each other, and the positive electrode case (100) and the negative electrode case (200) are surrounded to form a cavity (101); The positive electrode powder layer (400) is disposed in the cavity (101); The current collector (300) is disposed in the cavity (101), the current collector (300) and the positive electrode powder layer (400) are disposed in a stacked manner, at least a portion of the current collector (300) is embedded in the positive electrode powder layer (400), and the surface of the current collector (300) that is away from the positive electrode powder layer (400) is disposed in contact with a bottom surface of the positive electrode case (100). A button battery characterized by:

2. The current collector (300) has a mesh structure. The button battery of claim 1.

3. The surface of the current collector (300) that is embedded in the positive electrode powder layer (400) is a frosted surface or a surface having burrs. The button battery of claim 1.

4. The height to which the current collector (300) is embedded in the positive electrode powder layer (400) is 50% to 95% of the total height of the current collector (300). The button battery of claim 1.

5. The current collector (300) includes a plurality of current collector bars (310) arranged to cross each other, the plurality of current collector bars (310) are formed in a mesh structure, and the thickness of the intersections (320) of the plurality of current collector bars is greater than the thickness of the current collector bars (310). The button battery according to claim 2.

6. The material of the current collector (300) is nickel, aluminum, or stainless steel; The button battery of claim 1.

7. The compaction density of the positive electrode powder layer (400) is 2.0 to 3.0 g / mm ３ That is, The button battery of claim 1.

8. The cross sections of the current collector (300) and the positive electrode powder layer (400) are circular, and the ratio of the cross-sectional diameters of the current collector (300) and the positive electrode powder layer (400) is 1:1 to 1:1.5; The button battery of claim 1.

9. The mesh of the current collector (300) is rhombic, and the ratio of the length a of the short diagonal of the rhombic shape to the length b of the long diagonal of the rhombic shape is 1:1 to 1:3; The button battery according to claim 2.

10. The surface of the positive electrode powder layer (400) that contacts the current collector (300) and the longitudinal section of the current collector (300) are both wavy, or the surface of the positive electrode powder layer (400) that contacts the current collector (300) and the longitudinal section of the current collector (300) are both zigzag.

10. A button battery according to any one of claims 1 to 9.

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