Fully-sealed battery and preparation method thereof

Abstract

The invention provides a fully-sealed battery and a preparation method thereof, the fully-sealed battery comprises a battery cell, a battery shell and a kovar alloy cover body, the battery shell and the kovar alloy cover body are connected to form a sealed cavity, the battery cell is packaged in the sealed cavity, and the kovar alloy cover body is connected with a battery cell tab. The invention provides a preparation method of a fully-sealed battery. A kovar alloy cover body is connected with a battery cell tab through a transition solder in a welding manner; the preparation material of the battery shell comprises stainless steel; and the battery shell is connected with the kovar alloy cover body in a laser welding manner. The method has the beneficial effects that the leakage rate of the lithium carbon fluoride battery can be reduced, the process is simple, and the manufacturing cost and the battery performance can be ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and particularly relates to a fully sealed battery and a preparation method thereof. Background Art

[0002] In the existing technology, lithium carbon monofluoride batteries have broad application prospects in many fields due to their high energy density, long life and other advantages. However, batteries prepared by traditional methods often have difficulty in effectively controlling the leakage of the electrolyte inside the battery, resulting in unstable battery performance and reduced safety. For example, during high temperature, high humidity environments or long-term storage, due to insufficient sealing structures or sealing materials, gas or electrolyte may leak out, which not only causes attenuation of battery capacity and increase of internal resistance, but may also lead to serious consequences such as internal short circuit and corrosion of the battery, greatly limiting the application of lithium carbon monofluoride batteries in fields with high reliability requirements, such as aerospace and high-end electronic devices. Currently, there are many deficiencies in the methods for solving the leakage rate problem. For example, although some sealing materials can reduce the leakage rate, they will increase the internal resistance of the battery and affect the overall performance; some improved structures are complex, with high manufacturing process difficulty and cost, which is not conducive to the large-scale production of lithium carbon monofluoride batteries. There is an urgent need for a lithium carbon monofluoride battery structure that can solve the technical problems of reducing the leakage rate, ensuring battery performance, and having a simple preparation method and reasonable manufacturing cost. Summary of the Invention

[0003] To solve the above technical problems, the present invention provides a fully sealed battery and a preparation method thereof, which are particularly suitable for reducing the leakage rate of lithium carbon monofluoride batteries, and can also ensure battery performance and manufacturing cost.

[0004] The technical solution adopted by the present invention is: a fully sealed battery, including an electrode core, a battery housing and a kovar alloy cover. The battery housing is connected to the kovar alloy cover to form a sealed cavity, the electrode core is encapsulated in the sealed cavity, and the kovar alloy cover is connected to the electrode tab of the electrode core.

[0005] Preferably, the kovar alloy cover is connected to the positive electrode tab.

[0006] A preparation method of a fully sealed battery, wherein the kovar alloy cover is connected to the electrode tab of the electrode core by a welding method.

[0007] Preferably, the welding method is one or a combination of ultrasonic welding, resistance welding, and laser welding.

[0008] Preferably, the kovar alloy cover is connected to the electrode tab of the electrode core through a transition solder, and the preparation materials of the transition solder are one or a combination of aluminum-nickel composite tape, aluminum-molybdenum alloy, copper, and titanium.

[0009] Preferably, the preparation material of the battery housing includes stainless steel, and the preparation material of the positive electrode tab includes aluminum.

[0010] Preferably, the battery case and the kovar alloy cover are connected by laser welding.

[0011] The advantages and positive effects of the present invention are as follows: By adopting the above technical solution, the leakage rate of the lithium carbon monofluoride battery can be reduced; it has the advantages of simple process, ensuring the manufacturing cost and battery performance, etc. Description of the Drawings

[0012] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0013] Figure 2 is a schematic diagram of the connection principle between the kovar alloy cover and the electrode tab of the battery cell in an embodiment of the present invention;

[0014] In the figure:

[0015] 1. Battery cell 2. Battery case 3. Kovar alloy cover

[0016] 4. Positive electrode tab 5. Transition solder Detailed Embodiments

[0017] The following describes the embodiments of the present invention with reference to the drawings. The described embodiments are only a part of the embodiments of the invention, rather than all of the embodiments.

[0018] The following details the embodiments of the present invention. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar units or units with the same or similar functions throughout.

[0019] The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention, and should not be construed as a limitation to the present invention. In the description of the present invention, it should be understood that terms such as "installation", "connection", "fixation" should be understood in a broad sense, which can be direct connection, installation or fixation, or indirect connection, installation or fixation. The present invention does not limit this.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the structure or unit referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0021] As Figures 1 to 2As shown in the figure, a schematic diagram of an embodiment of a fully sealed battery according to the present invention includes a battery cell 1, a battery housing 2, and a kovar alloy cover 3. The battery housing 2 is connected to the kovar alloy cover 3 to form a sealed cavity. The battery cell 1 is encapsulated in the sealed cavity, and the kovar alloy cover 3 is connected to the battery cell tab.

[0022] In this embodiment, the kovar alloy cover 3 is connected to the positive tab 4, and the preparation material of the positive tab 4 includes aluminum.

[0023] On the other hand, the present invention also provides a method for manufacturing a fully sealed battery, including the following steps: The kovar alloy cover 3 is connected to the battery cell tab by a welding method.

[0024] The welding method is one or a combination of ultrasonic welding, resistance welding, and laser welding.

[0025] The kovar alloy cover 3 is connected to the battery cell tab through a transition solder 5. The preparation material of the transition solder 5 is one or a combination of aluminum-nickel composite tape, aluminum-molybdenum alloy, copper, and titanium. The kovar alloy cover 3 is welded to the positive tab 4 through the transition solder 5, that is, the kovar alloy cover 3 is welded to the aluminum tab through the transition solder 5. The welding method is one or a combination of ultrasonic welding, resistance welding, and laser welding. The transition solder 5 is welded to the battery cell tab to be welded, and then the transition solder 5 is welded to the kovar alloy cover 3. The melting point of the preparation material of the transition solder 5 is lower than that of the battery cell tab and the kovar alloy cover 3 to be welded. By using the transition solder 5 for connection, welding of two metals with a large difference in melting points, such as an aluminum tab and a cover made of kovar alloy, can be achieved, ensuring the welding strength and the high reliability of the battery.

[0026] Preferably, the preparation material of the battery housing 2 includes stainless steel. The wall thickness of the stainless steel battery housing 2 is not less than 0.3 mm and not more than 0.6 mm.

[0027] The battery housing 2 and the kovar alloy cover 3 are connected by a laser welding method. More specifically, the stainless steel battery housing 2 and the kovar alloy cover 3 are connected by a laser welding method to form a sealed cavity. Laser welding does not involve sealing materials, has a simple structure and good sealing effect, can ensure the manufacturing cost and simplify the manufacturing process.

[0028] The connection between the aluminum tab and the kovar alloy cover 3 can be achieved by filtering the solder 5, ensuring the high reliability of the battery and guaranteeing the battery performance; the sealing method adopts laser welding to ensure the low leakage rate of the battery; the battery case 2 and the kovar alloy cover 3 are made of stainless steel and used in combination, both having good sealing performance and high strength, ensuring that the battery is not easily deformed or cracked under different usage scenarios and external force environments, thereby ensuring that the leakage rate meets the product performance requirements. The present invention can not only reduce the leakage rate, but also guarantee the overall performance, with a simple structure, and can avoid affecting large-scale production or being unable to be popularized and applied due to complex manufacturing processes and low manufacturing costs.

[0029] The embodiments of the present invention have been described in detail above, but the content described is only the preferred embodiments of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. A fully sealed battery, characterized in that: The invention comprises a battery cell, a battery shell and a Kovar alloy cover, wherein the battery shell is connected to the Kovar alloy cover to form a sealed cavity, the battery cell is encapsulated in the sealed cavity and the Kovar alloy cover is connected to the battery cell tab.

2. The fully sealed battery according to claim 1, characterized in that: The Kovar alloy cover is connected to the positive electrode tab.

3. A method for preparing a fully sealed battery according to claim 1 or 2, characterized in that: The Kovar alloy cover is connected to the battery cell tab by welding.

4. The preparation method according to claim 3, characterized in that: The welding method is one or a combination of ultrasonic welding, resistance welding and laser welding.

5. The preparation method according to claim 3, characterized in that: The Kovar alloy cover is connected to the battery cell tab via a transition solder, and the transition solder is made of one or more combinations of aluminum-nickel composite strip, aluminum-molybdenum alloy, copper, and titanium.

6. The preparation method according to claim 3, characterized in that: The battery shell is made of stainless steel, and the positive electrode tab is made of aluminum.

7. The preparation method according to claim 6, characterized in that: The battery shell and the Kovar alloy cover are connected by laser welding.

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