Lithium-manganese button cell

Abstract

The utility model provides a lithium-manganese button cell which comprises a positive pole shell, a positive pole cover is coaxially sleeved in the positive pole shell, an annular metal base is arranged on the outer bottom surface of the positive pole cover, and the central axis of the metal base coincides with the central axis of the positive pole cover. And the opening edge part of the opening at one end of the metal base opposite to the anode cover is in contact fit with the inner bottom surface of the anode shell. According to the lithium-manganese button cell disclosed by the utility model, the expansion of the positive plate can be inhibited through the positive cover, and the assembly tightness of each component of the cell can be improved through the annular metal base; the openings in the two ends of the metal base are in one-to-one correspondence contact and fit with the outer bottom surface of the positive electrode cover and the inner bottom surface of the positive electrode shell respectively, the fit area is small, the situation that local fit is not tight is not prone to occurring, air in the battery can be exhausted completely when the battery is sealed, and it is avoided that the performance and consistency of the battery are affected by air remaining in the battery.

Description

Technical Field

[0001] The utility model relates to the field of button batteries, in particular to a lithium-manganese button battery. Background Art

[0002] The lithium-manganese button battery includes a negative electrode cover, a negative electrode lithium sheet, a separator, a positive electrode sheet and a positive electrode shell that are stacked in sequence along the axial direction of the battery. During the discharge process, the metallic lithium as the negative electrode is embedded in the positive electrode material, which usually causes the volume expansion of the positive electrode sheet. The volume expansion of the positive electrode sheet includes lateral expansion and longitudinal expansion. Usually, the lateral expansion trend of the positive electrode sheet is much greater than the longitudinal expansion trend of the positive electrode sheet. In order to prevent the lateral expansion of the positive electrode sheet from causing loose contact between the negative electrode lithium sheet, separator, positive electrode sheet, positive electrode shell, etc., the positive electrode sheet is usually placed in a cylindrical positive electrode cover, so that the positive electrode can better exert its capacity. At the same time, the close axial contact between the negative electrode cover, negative electrode lithium sheet, separator, positive electrode sheet, positive electrode cover and positive electrode shell is a key factor in reducing the internal resistance of the battery and improving the battery discharge performance. Generally speaking, to ensure a tight fit within the battery, the center of the positive electrode casing is punched into a curved shape. Furthermore, during battery assembly, the order is: prepare the negative electrode casing and lithium metal - place the separator - inject the electrolyte - add the positive electrode sheet - and finally, cover the positive electrode casing. During the final process of covering the positive electrode casing, this concave curvature can easily trap gas inside the battery. Furthermore, the outer bottom surface of the positive electrode cover of a lithium-manganese button battery fits snugly against the inner bottom surface of the positive electrode casing, with the contact area between the two being comparable to the outer bottom surface of the positive electrode cover. This can sometimes lead to localized looseness in the contact area between the outer bottom surface of the positive electrode cover and the inner bottom surface of the positive electrode casing, impacting battery performance and consistency. Utility Model Content

[0003] The purpose of the utility model is to provide a lithium manganese button battery.

[0004] The technical solution for achieving the purpose of the utility model is: a lithium-manganese button battery, comprising a positive electrode shell, a positive electrode cover coaxially mounted within the positive electrode shell, an annular metal base provided on the outer bottom surface of the positive electrode cover, the central axis of the metal base coinciding with the central axis of the positive electrode cover, and an open edge of the metal base at one end facing away from the positive electrode cover in contact with the inner bottom surface of the positive electrode shell.

[0005] The lithium-manganese button battery of the present invention can not only suppress the expansion of the positive electrode sheet through the positive electrode cover, but also improve the tightness of the assembly of the various battery components through the annular metal base. In this case, there is no need to punch the middle of the positive electrode shell into a circular arc shape with a certain curvature. Moreover, because the metal base is annular and the openings at both ends respectively contact and fit with the outer bottom surface of the positive electrode cover and the inner bottom surface of the positive electrode shell in a one-to-one correspondence, the contact area between the metal base and the positive electrode cover (or positive electrode shell) is much smaller than the area of the outer bottom surface of the positive electrode cover. The fitting area is small, and it is less likely to have a local loose fit. This helps to completely discharge the air inside the battery when the battery is sealed, thereby preventing the air trapped inside the battery from affecting the battery performance and consistency.

[0006] Furthermore, the positive electrode cover and the metal base are integrally formed. Of course, the two can also be made separately and then fixed together, but the integrally formed setting is more beneficial to reducing the internal resistance of the battery.

[0007] The metal base is preferably trumpet-shaped. This trumpet-shaped metal base has a small contact area with the positive electrode cover and the positive electrode shell, making it difficult to trap air. Furthermore, during battery assembly, when electrolyte is injected into the positive electrode shell, the central cavity of the metal base can also store electrolyte. In a specific implementation, the diameter of the opening of the metal base facing the positive electrode cover is larger than the diameter of the opening facing away from the positive electrode cover, or the diameter of the opening of the metal base facing the positive electrode cover is smaller than the diameter of the opening facing away from the positive electrode cover.

[0008] Furthermore, the diameter of the opening of the end of the metal base facing the positive electrode cover is equal to the diameter of the outer bottom surface of the positive electrode cover, which has the best stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of the axial cross-sectional structure of the lithium manganese button battery of Example 1;

[0010] Figure 2 Schematic diagram of the top view of the positive electrode cover of Example 1;

[0011] Figure 3 Schematic diagram of the bottom view of the positive electrode cover of Example 1;

[0012] Figure 4 Schematic diagram of the axial cross-sectional structure of the lithium-manganese button battery of Example 2;

[0013] Figure 5 Schematic diagram of the top view of the positive electrode cover of Example 2;

[0014] Figure 6 This is a schematic diagram of the bottom structure of the positive electrode cover of Example 2. DETAILED DESCRIPTION

[0015] The preferred embodiment of the lithium manganese button battery of the present invention will be described in detail below with reference to the accompanying drawings. Example 1

[0016] Combine Figures 1 to 3 A lithium-manganese button battery comprises a positive electrode shell 10, a positive electrode cover 20 being coaxially mounted within the positive electrode shell 10, an annular metal base 40 being provided on the outer bottom surface of the positive electrode cover 20, the central axis of the metal base 40 coinciding with the central axis of the positive electrode cover 20, and an open edge of the metal base 40 facing away from the positive electrode cover 20 being in contact with the inner bottom surface of the positive electrode shell 10;

[0017] The metal base 40 is trumpet-shaped, and the opening diameter of the metal base 40 facing the positive electrode cover 20 is smaller than the opening diameter of the metal base 40 facing away from the positive electrode cover 20 . Example 2

[0018] Combine Figures 4 to 6 Compared with Example 1, the lithium manganese button cell of Example 2 is different in that the opening diameter of the metal base 40 facing the positive electrode cover 20 is larger than the opening diameter of the metal base 40 facing away from the positive electrode cover 20 .

[0019] like Figure 1 、 Figure 4 As shown, when assembling the battery, the positive electrode sheet 30 is coaxially installed in the positive electrode cover 20.

[0020] The lithium-manganese button batteries of Examples 1 and 2 both suppress expansion of the positive electrode sheet 30 through the positive electrode cover 20 and enhance the tightness of assembly of the battery components through the annular metal base 40. The positive electrode case 10 has a horizontal bottom wall, which prevents air from being trapped within the battery. Furthermore, because the metal base 40 is annular and its two end openings correspond to and mate with the outer and inner bottom surfaces of the positive electrode cover 20 and 10, respectively, the contact area between the metal base 40 and the positive electrode cover 20 (or positive electrode case 10) is much smaller than the outer bottom surface of the positive electrode cover 20. This small contact area reduces the likelihood of localized loose fit, facilitating the complete removal of air from the battery during sealing and preventing trapped air from impacting battery performance and consistency. Furthermore, the trumpet-shaped metal base 40 minimizes air trapping while maintaining a central cavity within the positive electrode cover 20 and 10 during battery assembly.

[0021] Of course, the metal base 40 may be, but is not limited to, a trumpet shape, and may also be a straight cylinder shape.

[0022] The axial height of the metal base 40 of the present invention is determined by "ensuring a close fit between the battery components while not reducing the effective internal volume of the battery."

[0023] like Figure 1 、 Figure 4 As shown, the positive electrode cover 20 and the metal base 40 are preferably formed in one piece. Of course, the two can also be made separately and then fixed together, but the one-piece forming arrangement is more beneficial to reducing the internal resistance of the battery.

[0024] Preferably, Figure 1 、 Figure 4 As shown, the opening diameter of the metal base 40 facing the positive electrode cover 20 is equal to the outer bottom diameter of the positive electrode cover 20, which provides the best stability. Of course, the opening diameter of the metal base 40 facing the positive electrode cover 20 can also be smaller than the outer bottom diameter of the positive electrode cover 20.

[0025] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, is also included in the patent protection scope of the present invention.

Claims

1. A lithium-manganese button battery comprising a positive electrode shell, wherein a positive electrode cover is coaxially mounted within the positive electrode shell, characterized in that: An annular metal base is provided on the outer bottom surface of the positive electrode cover, the central axis of the metal base coincides with the central axis of the positive electrode cover, and the opening edge of the metal base facing away from the positive electrode cover contacts and fits with the inner bottom surface of the positive electrode shell.

2. The lithium manganese button battery according to claim 1, characterized in that: The positive electrode cover and the metal base are integrally formed.

3. The lithium manganese button battery according to claim 1, characterized in that: The metal base is trumpet-shaped.

4. The lithium manganese button battery according to claim 3, characterized in that: The diameter of the opening of the metal base at one end facing the positive electrode cover is larger than the diameter of the opening of the metal base at one end facing away from the positive electrode cover.

5. The lithium manganese button battery according to claim 3, characterized in that: The diameter of the opening of the metal base at one end facing the positive electrode cover is smaller than the diameter of the opening of the metal base at one end facing away from the positive electrode cover.

6. The lithium manganese button battery according to claim 1, characterized in that: The diameter of the opening of one end of the metal base facing the positive electrode cover is equal to the diameter of the outer bottom surface of the positive electrode cover.

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