A lithium-manganese button cell with double-layer metal current collector

Abstract

This invention provides a lithium-manganese button battery with a double-layer metal current collector, comprising: a positive electrode shell; a negative electrode cover, which is fitted onto the positive electrode shell, with a sealing ring between them to achieve a tight seal; a negative electrode lithium metal, pressed onto the inner bottom surface of the negative electrode cover; a separator, disposed on the surface of the negative electrode lithium metal; a positive electrode sheet, stacked on the separator, with a double-layer metal current collector and a current collector ring pressed onto the positive electrode sheet, the double-layer metal current collector elastically pressing against the inner bottom surface of the positive electrode shell; and an electrolyte, stored around the positive electrode sheet and between the double-layer metal current collector. This invention solves the technical problem that, with the increase in the thickness of lithium-manganese button batteries, poor contact between the positive electrode sheet and the positive electrode shell due to thickness tolerance of the positive electrode sheet and the influence of centrifugal force on batteries used in vehicle tire pressure alarms leads to a decrease in battery performance or even failure.

Description

Technical Field

[0001] This utility model relates to the technical field of lithium manganese button batteries, and in particular to a lithium manganese button battery with a double-layer metal current collector. Background Technology

[0002] Lithium manganese button batteries are widely used in car remote keys, tire pressure alarms, medical equipment (such as thermometers), and backup power for electronic devices.

[0003] To meet the demand for high capacity, the thickness of some battery models (such as CR2477 and CR2050) has been increased, but this has also brought new problems. For example, traditional positive electrode sheets are made by granulating powders such as manganese powder and graphite powder and then pressing them. Due to the thickness tolerance of powder pressing (the tolerance for thick batteries can reach 0.1-0.2mm or more), the thinner parts of the positive electrode sheet are prone to poor contact with the positive electrode shell, resulting in a decrease in electrical performance. In addition, batteries used in car tire pressure monitoring systems also need to withstand the centrifugal force of high-speed rotation, which can cause the positive electrode sheet to loosen and shift, further aggravating poor conductivity and even causing battery failure.

[0004] Based on this, Japanese manufacturers have improved contact by adding conductive adhesive or metal retaining rings, but this has problems such as complex processes, difficult installation, and high costs, so there is an urgent need to optimize the technical solutions. Utility Model Content

[0005] The purpose of this utility model is to provide a lithium manganese button battery with a double-layer metal current collector, which solves the technical problem that, after the thickness of the lithium manganese button battery is increased, the positive electrode sheet and the positive electrode shell will have poor contact due to the thickness tolerance of the positive electrode sheet and the centrifugal force of the vehicle, which will cause the battery performance to decline or even fail.

[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows: This utility model provides a lithium-manganese button battery with a double-layer metal current collector, comprising: a positive electrode shell; a negative electrode cover, which is fitted onto the positive electrode shell, and a sealing ring is provided between the two to achieve a tight seal; a negative electrode lithium metal, which is pressed onto the inner bottom surface of the negative electrode cover; a separator, which is disposed on the surface of the negative electrode lithium metal; a positive electrode sheet, which is stacked on the separator, and a double-layer metal current collector and a current collector ring are pressed onto the positive electrode sheet, and the double-layer metal current collector elastically abuts against the inner bottom surface of the positive electrode shell; and an electrolyte, which is stored around the positive electrode sheet and between the double-layer metal current collector.

[0007] Furthermore, the double-layer metal current collector includes: an inner metal current collector, in which the positive electrode sheet is embedded on its inner side with an embedding thickness of 50%-60%, and the outer side is exposed to form a conductive contact surface; and an outer metal current collector, which is pressed onto the conductive contact surface of the inner metal current collector by a pressure mold and the current collector ring; wherein, after the outer metal current collector is pressed, an arc-shaped protrusion with elastic expansion and contraction is formed in the inner hole of the current collector ring.

[0008] Furthermore, the top surface of the arc-shaped protrusion forms a surface contact with the inner bottom surface of the positive electrode shell; the arc-shaped protrusion structure can generate an elastic deformation of 0.2-1.0 mm under pressure.

[0009] Furthermore, the current collector ring includes an integrally connected axial ring portion and a radial ring portion, which are used to mount the positive electrode sheet and press the outer metal current collector mesh, respectively.

[0010] Furthermore, the thickness of the collector ring is 0.15-0.35 mm, and its inner hole size is 70% to 90% of the outer diameter.

[0011] Furthermore, an electrolyte storage cavity is formed between the two layers of metal current collectors.

[0012] Compared with the prior art, the present invention has at least the following beneficial effects: This invention utilizes a double-layer metal current collector and current collector ring on the positive electrode sheet. The elasticity of the double-layer metal current collector allows it to press firmly against the inner bottom surface of the positive electrode casing, effectively compensating for thickness tolerances of the positive electrode sheet and resisting centrifugal forces in applications such as vehicle tire pressure monitoring systems. This ensures constant tight contact between the positive electrode sheet and the positive electrode casing, solving the problem of battery performance degradation or even failure caused by poor contact. Furthermore, compared to existing technologies, this application has a simpler structure, is easier to manufacture, and reduces process complexity and cost. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the positive electrode sheet provided in this embodiment; Figure 2 This is a cross-sectional view of the positive electrode sheet provided in this embodiment; Figure 3 This is a schematic diagram of the positive electrode sheet before assembly, as provided in this embodiment. Figure 4 This is a partial cross-sectional view of the lithium manganese button battery provided in this embodiment.

[0015] icon: 100 - Positive electrode plate; 120 - Metal current collector; 121 - Inner metal current collector; 122 - Outer metal current collector; 123 - Arc-shaped protrusion; 130 - Current collector ring; 131 - Axial ring; 132 - Radial ring; 133 - Inner hole; 200 - Positive electrode casing; 300 - Negative electrode cap; 400 - Negative electrode lithium metal; 500 - Separator; 600 - Sealing ring. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0018] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0019] Please refer to Figure 1-4As shown, this embodiment provides a lithium-manganese button battery with a double-layer metal current collector 120, including a positive electrode shell 200, a negative electrode cover 300 that covers the positive electrode shell 200 and is tightly sealed by a sealing ring 600, a negative electrode lithium metal 400 pressed onto the inner bottom surface of the negative electrode cover 300, a separator 500 disposed on the surface of the negative electrode lithium metal 400, a positive electrode sheet 100 superimposed on the separator 500, and a double-layer metal current collector 120 and a current collector ring 130 pressed onto the positive electrode sheet 100 (wherein, the current collector ring 130 is pressed onto the double-layer metal current collector 120 and fitted onto the positive electrode sheet 100, the double-layer...). The metal current collector 120 (specifically, the inner hole of the current collector ring 130 protruding from the center of the outer metal current collector) elastically abuts against the inner bottom surface of the positive electrode shell 200 and the electrolyte stored around the positive electrode sheet 100 and between the two metal current collectors 120. This solution, through the elastic abutment design of the double metal current collector 120, solves the problem of poor contact or even failure between the positive electrode sheet 100 and the positive electrode shell 200 caused by the thickness tolerance of the positive electrode sheet 100 and centrifugal force after the battery thickness increases, thus ensuring the stability of battery performance. Compared with the traditional solution using conductive adhesive or metal fixing rings, the structure is simpler and easier to manufacture.

[0020] In this embodiment, the double-layer metal current collector 120 includes an inner layer and an outer layer. The inner metal current collector 121 has 50%-60% (embedding thickness percentage) of its inner side embedded in the positive electrode 100, with its outer side exposed to form a conductive contact surface. The outer metal current collector 122 is pressed onto the conductive contact surface of the inner layer using a pressure mold and a current collector ring 130. After pressing, the outer metal current collector 122 forms a 0.2-1.0mm elastically expandable arc-shaped protrusion 123 in the inner hole 133 of the current collector ring 130. That is, by partially embedding the inner current collector into the positive electrode 100, and then using a pressure mold to press the outer current collector and current collector ring 130 onto the exposed surface of the inner layer, the arc-shaped protrusion 123 can be formed by controlling the pressing process. This solution uses a double-layer metal current collector 120 structure and an outer arc-shaped protrusion 123 design. The elastic expansion and contraction of the arc-shaped protrusion 123 compensates for the thickness tolerance of the positive electrode sheet 100, which enhances the contact reliability with the positive electrode shell 200. Compared with a single-layer current collector, it has better elasticity and better resistance to centrifugal force.

[0021] In this embodiment, the top surface of the arc-shaped protrusion 123 forms a surface contact with the inner bottom surface of the positive electrode shell 200, and the arc-shaped protrusion 123 structure can generate an elastic deformation of 0.2-1.0 mm under pressure. In this solution, the surface contact increases the conductive area and reduces the contact resistance. The use of an elastic deformation of 0.2-1.0 mm ensures that tight contact can still be maintained under thickness tolerance and centrifugal force, thereby improving conductivity and structural stability.

[0022] In this embodiment, the current collector ring 130 includes an integrally connected axial ring portion 131 and a radial ring portion 132, which are used to mount the positive electrode 100 and press the outer metal current collector mesh 122, respectively. This design enhances structural strength by dividing the functions of the axial and radial ring portions 132 in an integral structure, and ensures the fixation of the positive electrode 100 and the pressing effect of the outer metal current collector mesh 122, thereby improving the overall structural stability.

[0023] In this embodiment, the thickness of the current collecting ring 130 is 0.15-0.35 mm, and the inner hole 133 is 70% to 90% of the outer diameter. This size design balances the structural strength and elastic space of the current collecting ring 130. The inner hole 133 provides sufficient space for the arc-shaped protrusion 123 of the outer metal current collecting mesh 122, and the thickness ensures that the current collecting ring 130 is not easily deformed, thus improving the adaptability and reliability of the overall structure.

[0024] In this embodiment, an electrolyte storage cavity is formed between the two layers of metal current collectors. This design increases the electrolyte storage capacity, ensures the sufficiency of the battery reaction, and extends battery life. Simultaneously, the use of the double-layer metal current collector structure to form the storage cavity optimizes the storage and distribution of the electrolyte, improving discharge performance.

[0025] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A lithium-manganese button cell having a double-layer metal current collector, characterized in that, include: Positive electrode casing (200); A negative electrode cover (300) is fitted onto the positive electrode shell (200), and a sealing ring (600) is provided between the two to achieve a tight seal. Lithium metal (400) is pressed onto the inner bottom surface of the negative electrode cap (300); A separator (500) is disposed on the surface of the negative electrode lithium metal (400); A positive electrode sheet (100) is stacked on a separator (500). A double-layer metal current collector (120) and a current collector ring (130) are pressed onto the positive electrode sheet (100). The double-layer metal current collector (120) elastically abuts against the inner bottom surface of the positive electrode shell (200). The electrolyte is stored around the positive electrode (100) and between the double-layer metal current collector (120).

2. The lithium-manganese button cell having a double-layer metal current collector of claim 1, wherein, The double-layer metal current collector (120) includes: The inner metal current collector (121) has the positive electrode (100) embedded on its inner side, with an embedding thickness of 50%-60%, and its outer side is exposed to form a conductive contact surface. The outer metal current collector (122) is pressed onto the conductive contact surface of the inner metal current collector (121) by a pressure mold and the current collector ring (130); wherein, after the outer metal current collector (122) is pressed, an arc-shaped protrusion (123) with elastic expansion and contraction is formed in the inner hole (133) of the current collector ring (130).

3. The lithium-manganese button cell having a double-layer metal current collector of claim 2, wherein, The top surface of the arc-shaped protrusion (123) forms a surface contact with the inner bottom surface of the positive electrode shell (200); the arc-shaped protrusion (123) structure can generate an elastic deformation of 0.2-1.0 mm under pressure.

4. The lithium-manganese button cell having a double-layer metal current collector of claim 2, wherein, The current collector ring (130) includes an integrally connected axial ring portion (131) and a radial ring portion (132), which are used to mount the positive electrode sheet (100) and press the outer metal current collector mesh (122), respectively.

5. The lithium-manganese button cell having a double-layer metal current collector of any one of claims 1 to 4, characterized in that The thickness of the collector ring (130) is 0.15-0.35 mm, and the inner hole (133) is 70% to 90% of the outer diameter.

6. The lithium-manganese button cell having a double-layer metal current collector of any one of claims 1 to 4, characterized in that An electrolyte storage cavity is formed between the two layers of metal current collectors (120).

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