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 from 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. This application relates to the technical field of batteries, for example button batteries. [Background technology]

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

[0003] Currently, most lithium manganese button battery cells have 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 and a relatively short service life of the battery cell.

[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 with 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 surrounding each other to form a cavity, the positive electrode powder layer disposed in the cavity, the current collector disposed in the cavity, the current collector and the positive electrode powder layer disposed in a stacked arrangement, at least a portion of the current collector embedded in the positive electrode powder layer, and a surface of the current collector facing away from the positive electrode powder layer abutting against a 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 with 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 structure, and the thickness of the crossings of the plurality of collector bars being greater than the thickness of the collector bars.

[0011] In one embodiment, the current collector is made of 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 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 diameters of the cross sections 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 that contacts the current collector and the longitudinal cross section of the current collector are both wavy, or the surface of the positive electrode powder layer that contacts the current collector and the longitudinal cross section of the current collector are both zigzag. [Effects of the Invention]

[0016] In the button battery according to the present invention, a cavity for accommodating the positive electrode powder layer and the current collector is formed by assembling the positive electrode case and the negative electrode case. By embedding at least a portion of the current collector in the positive electrode powder layer, the space occupied by the current collector in the case can be reduced, thereby appropriately increasing the volume of the positive electrode powder layer, thereby further increasing the battery cell capacity and extending the battery life. [Brief explanation 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. [Figure 2] 1 is a schematic diagram of the structure of a roll-shaped current collector according to Example 1 of the present invention. [Figure 3] FIG. 2 is a schematic diagram of the structure of a current collector according to Example 1 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. [Figure 5] FIG. 10 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 INVENTION

[0018] In the description of this application, it should be explained that the orientations or positional relationships indicated by terms such as "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inside," and "outside" are merely for the purpose of facilitating and simplifying the description of this application and do not indicate or imply that the device must have a specific orientation, be configured, or operate in a specific direction. These are based on the orientations or positional relationships shown in the drawings and therefore cannot be understood as limiting this application. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and are not to be understood as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions, and the presence of a first feature "above," "on," and "above" a second feature includes the presence of the first feature directly above and diagonally above the second feature, or simply that the horizontal height of the first feature is higher than the horizontal height of the second feature. A first feature being "below," "below," and "under" 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 clearly stated that the terms "attached," "connected," and "connection" should be generally understood unless otherwise clearly specified and limited. For example, they can be fixedly connected, detachably connected, or integrally connected. They can be connected mechanically or electrically. They can be directly connected, indirectly connected via an intermediate medium, or communicate internally between two components. Those skilled in the art can understand the meaning of the above terms in this application depending on the context.

[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 exemplary only used to explain 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 enclosed to form a cavity 101. The positive electrode powder layer 400 is disposed within the cavity 101. The current collector 300 is disposed within the cavity 101, and the current collector 300 and the positive electrode powder layer 400 are stacked such that at least a portion of the current collector 300 is embedded within the positive electrode powder layer 400, and the surface of the current collector 300 facing away from the positive electrode powder layer 400 abuts against the bottom surface of the positive electrode case 100.

[0022] In the button battery, a cavity 101 is formed by assembling a positive electrode case 100 and a negative electrode case 200 to accommodate a positive electrode powder layer 400 and a current collector 300. By embedding at least a portion of the current collector 300 in the positive electrode powder layer 400, the current collector 300 occupies less space in the case 10 than when a positive electrode ring is installed, which allows the volume of the positive electrode powder layer to be appropriately increased, thereby further increasing the battery cell capacity and extending the battery life.

[0023] Continuing to refer to FIG. 1, the positive electrode case 100 and the negative electrode case 200 are vertically connected in a locking manner, 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 stacked in this order from top to bottom.

[0024] 2 and 3, the current collector 300 may optionally have a mesh structure. Alternatively, the current collector 300 may have an integrally formed mesh structure. The mesh structure of the current collector 300 facilitates embedding the current collector 300 in the positive electrode powder layer 400 and also helps to compress the current collector 300 and the positive electrode powder layer 400, thereby strengthening the connection between them. Optionally, in this embodiment, the raw material for the current collector 300 is in a roll shape. Before assembling the button battery, the rolled current collector 700 needs to be flattened 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 that is 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 thereto. By embedding a portion 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 and battery life can be further improved.

[0027] The current collector 300 includes a plurality of cross-arranged collector bars 310, which are formed in a mesh structure, and the thickness of the intersections 320 of the cross-collector bars is greater than the thickness of the current collector bars 310. In this embodiment, the thickness of the intersections 320 of the cross-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 cross-collector bars 310. Increasing the thickness of the intersections 320 of the cross-collector bars can increase the structural strength of the current collector 300 and prevent damage to the current collector 300 during assembly or use.

[0028] The mesh of the current collector 300 is diamond-shaped, and the ratio of the length a of the long diagonal of the diamond to the length b of the short diagonal is 1:1 to 1:3, and may be, for example, 1:1, 1:2, 1:3, or another ratio, which may be selected depending on the battery model. The provision of the mesh makes it easier to press the current collector 300 into the positive electrode powder layer 400, reducing the difficulty of processing.

[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 performance of the battery cell. The current collector 300 made of nickel or aluminum has a relatively strong performance in terms of large current pulses.

[0030] The positive electrode powder layer 400 is mainly 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 set to 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, such as 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, with the cross-sectional area of ​​the current collector 300 being 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 current collector 300 into positive electrode powder layer 400 using a press. A negative electrode sheet 600 is loaded into negative electrode case 200, cut separator 500 is placed on negative electrode sheet 600, electrolyte is dripped onto separator 500, and after dripping is complete, positive electrode powder layer 400 is placed on separator 500, and positive electrode case 100 is engaged with 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 of 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 complete, 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 pressure generated after the positive electrode case 100 and the negative electrode case 200 are engaged embeds the current collector 300 in the positive electrode powder layer 400.

[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, a positive electrode is produced by pressing and embedding the current collector 300 into the positive electrode powder layer 400 using a press. The die used to press the current collector 300 and the positive electrode powder layer 400 together using the press is wavy or zigzag, so that the surface of the positive electrode powder layer 400 that contacts the current collector 300 and the longitudinal cross section of the current collector 300 both have a wavy shape, or the surface of the positive electrode powder layer 400 that contacts the current collector 300 and the longitudinal cross section of the current collector 300 both have a zigzag shape. The use of a wavy or zigzag die increases the bonding strength between the current collector 300 and the positive electrode powder layer 400, preventing them from separating. 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 complete, 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 collecting bar 320: Intersection of current collecting 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) surround each other to form a cavity (101); The positive electrode powder layer (400) is placed in the cavity (101), The current collector (300) is placed in the cavity (101), the current collector (300) and the positive electrode powder layer (400) are stacked and arranged, 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 arranged to abut against the bottom surface of the positive electrode case (100), The current collector (300) includes a plurality of collector bars (310) arranged crosswise, the plurality of collector bars (310) are formed in a mesh structure, the thickness of the intersections (320) of the plurality of collector bars is greater than the thickness of the collector bars (310), and the thickness of the intersections (320) of the collector bars is 1.2 to 1.5 times the thickness of the collector bars (310). 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 with 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 material of the current collector (300) is nickel, aluminum, or stainless steel. The button battery of claim 1.

6. The compaction density of the positive electrode powder layer (400) is 2.0 to 3.0 g / cm 3; The button battery of claim 1.

7. The cross sections of the current collector (300) and the positive electrode powder layer (400) are circular, and the ratio of the diameters of the cross sections 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.

8. 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 is 1:1 to 1:

3. The button battery according to claim 2 .

9. 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.

9. The button battery according to claim 1.

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