Cylindrical battery cell and battery

Abstract

The invention relates to the technical field of battery sleeves or covers, in particular to a cylindrical battery cell and a battery. The invention provides a cylindrical battery cell which comprises a shell, the shell is made of a 2-series aluminum alloy material, the copper content in the shell is 3%-6.8%, and a UV glue protective layer is arranged in the shell. According to the cylindrical battery cell provided by the invention, the interior of the shell made of the 2-series aluminum alloy with relatively high copper content is coated with the UV glue protection layer, so that Cu in the shell cannot be separated out, the strength of the battery cell can be ensured to be qualified, and the safety performance of the battery cell is improved.

Description

Technical Field

[0001] The invention relates to the technical field of battery sleeves or covers, and in particular to a cylindrical battery core and a battery. Background Art

[0002] With the continuous development of the new energy industry, cylindrical batteries have become a major pillar of the industry due to their high production efficiency, high energy density and low manufacturing cost. Aluminum alloy is usually used as the shell of cylindrical batteries due to its advantages of low cost, low density and good formability.

[0003] Aluminum alloys exhibit different performance characteristics due to the addition of different metal elements. Among the metal elements, the elements that have a greater impact on the performance of aluminum alloys are copper (Cu), magnesium (Mg), silicon (Si), iron (Fe), manganese (Mn), nickel (Ni), zinc (Zn), etc. Among them, copper is an important alloying element in aluminum alloys, and has a certain solid solution strengthening effect. In addition, the CuAl2 precipitated by aging has a significant aging strengthening effect.

[0004] As an important alloying element in aluminum alloys, copper has its advantages and disadvantages. Advantages: good solid solution strengthening and aging strengthening effects, increasing the copper content, improving the fluidity, tensile strength and hardness of the alloy, improving mechanical properties and improving machinability. Disadvantages: reduced corrosion resistance and plasticity, and increased thermal cracking tendency.

[0005] When an aluminum shell is used for a cylindrical battery cell, the aluminum shell is generally connected to the positive electrode. Under the influence of the electrochemical potential, the Cu element on the inner surface of the aluminum shell will precipitate under the electrochemical environment, pass through the diaphragm and form a deposit on the negative electrode surface, causing the battery to self-discharge. The Cu content in 3 series aluminum alloy is ≤0.1%, so 3 series aluminum alloy is usually used for the shell of cylindrical batteries, because its low Cu content has little effect on the battery cell. However, the low Cu content also leads to lower strength and hardness of the aluminum shell, resulting in deviation in dimensional stability and low strength of the battery shell made of 3 series aluminum alloy. Summary of the invention

[0006] In view of the technical problems in the prior art that the shell made of 3 series aluminum alloy with lower copper content has low strength, and when the shell is made of 2 series aluminum alloy, copper will precipitate on the negative electrode surface to form a deposit, the present invention provides a cylindrical battery cell, and a UV glue protective layer is coated inside the shell made of 2 series aluminum alloy with higher copper content to solve the above technical problems.

[0007] The present invention provides a cylindrical battery core, comprising a shell, the shell is made of 2 series aluminum alloy, the copper content of the shell is 3%-6.8%, and a UV glue protective layer is arranged in the shell.

[0008] Furthermore, the copper content in the shell is 3%-5%.

[0009] Furthermore, the copper content in the shell is 3.8%-4.9%.

[0010] Furthermore, the thickness of the UV adhesive protective layer is 18-22 μm.

[0011] Furthermore, the thickness of the UV adhesive protective layer is 20 μm.

[0012] Furthermore, UV glue is evenly sprayed on the inner side of the shell to form a UV glue protective layer.

[0013] Furthermore, the chemical composition and content of the 2 series aluminum alloy are: Cu 3.8%-4.9%, Mn 0.30%-1.0%, Mg 1.2%-1.8%, Cr 0.10%, Si 0.50%, Zn 0.25%, and the balance is Al.

[0014] The present invention also provides a battery, comprising the cylindrical battery core.

[0015] The beneficial effects of the present invention are: A 2-series aluminum alloy material is used as the cylindrical battery cell shell. Since the Cu content in the 2-series aluminum alloy is 3%-6.8%, the strengthening effect of the aluminum alloy is the best, so that the hardness and strength of the shell are increased. The battery cell shell can provide a guarantee for the stability of the external dimensions of the battery cell, and the battery safety is improved. The present invention sprays a UV glue protective layer on the inner surface of the shell to isolate the shell from the electrolyte, thereby avoiding the precipitation of Cu in the aluminum alloy and avoiding affecting the self-discharge performance of the battery cell. The present invention can not only ensure that Cu in the shell will not precipitate, but also ensure that the strength of the battery cell is qualified, thereby improving the safety performance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0018] Figure 2 for Figure 1 A partial enlarged view of point A in the middle.

[0019] Description of main reference numerals 1- Shell, 2- UV adhesive protective layer. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0021] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a cylindrical battery cell, including a shell 1, the shell 1 is made of 2 series aluminum alloy, the copper content in the shell 1 is 3%-6.8%, and the copper content is 3% to 6.8%. The strengthening effect is good, the alloy has good fluidity, high tensile strength and hardness, high mechanical properties, and good cutting performance; UV glue is sprayed in the shell 1 to form a UV glue protective layer 2, which is cured by ultraviolet light to isolate the shell 1 from the electrolyte, avoid the precipitation of Cu in the aluminum alloy, avoid affecting the self-discharge performance of the battery cell, ensure that Cu in the shell 1 will not precipitate, ensure that the strength of the battery is qualified, and improve the safety performance of the battery cell. The thickness of the UV glue protective layer 2 is preferably 18-22μm. In a preferred embodiment of the present invention, the thickness of the UV glue protective layer 2 is 20μm.

[0022] In one embodiment of the present invention, the chemical composition and content of the shell 1 made of 2-series aluminum alloy are: Cu3.8%-4.9%, Mn0.30%-1.0%, Mg1.2%-1.8%, Cr0.10%, Si0.50%, Zn0.25%, and the balance is Al; the mechanical properties of the shell 1 in this embodiment are: tensile strength σb (MPa) ≥390, conditional yield strength σ0.2 (MPa) ≥245. In a comparative example of an aluminum alloy shell with less Cu content, Si0.60%, Fe0.70%, Cu0.05%-0.20%, Mn1.0%-1.5%, Zn0.10%, Al balance; the mechanical properties of the comparative example are: tensile strength σb (MPa) 142-178, conditional yield strength σ0.2 (MPa) ≥115. It can be seen that in the embodiments of the present invention, due to the high Cu content, good mechanical properties, high tensile strength and conditional yield strength, the battery cell has high tensile strength and hardness, high stability, and safer application; at the same time, the shell 1 of the battery cell of the present invention is sprayed with a 18-22μm UV glue protective layer 2 to isolate the shell 1 from the electrolyte, avoid Cu precipitation in the aluminum alloy, and avoid affecting the self-discharge performance of the battery cell, so that the battery cell of the embodiment of the present invention can ensure that Cu will not precipitate in the shell 1, and can also ensure that the strength of the battery cell is qualified, thereby improving the safety performance of the battery cell.

[0023] In a preferred embodiment of the present invention, the copper content of the shell 1 made of 2-series aluminum alloy is 3%-5%; in a more preferred embodiment, the copper content of the shell 1 made of 2-series aluminum alloy is 3.8%-4.9%. In the embodiment of the present invention, the copper content of the shell 1 made of 2-series aluminum alloy can be 3.8%, 4.0%, 4.2%, 4.3%, 4.5%, 4.7%, 4.9%, etc.

[0024] An embodiment of the present invention provides a battery, including a cylindrical battery cell, wherein the shell 1 of the battery cell is made of a 2-series aluminum alloy, the copper content in the shell 1 is 3%-6.8%, UV glue is sprayed inside the shell 1 to form a UV glue protective layer 2, and UV light is irradiated and cured to isolate the shell 1 from the electrolyte to prevent Cu precipitation in the aluminum alloy, and the thickness of the UV glue protective layer 2 is 18-22μm. In a preferred embodiment, the battery cell shell 1 of the battery is made of a 2-series aluminum alloy, the copper content in the shell 1 is 4%, and the thickness of the UV glue protective layer 2 in the shell 1 is 20μm.

[0025] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention.

Claims

1. A cylindrical battery cell, comprising a shell, characterized in that: The shell is made of 2 series aluminum alloy, the copper content in the shell is 3%-6.8%, and a UV glue protective layer is set inside the shell.

2. A cylindrical battery cell as claimed in claim 1, characterized in that: The copper content in the shell is 3%-5%.

3. A cylindrical battery cell as claimed in claim 1, characterized in that: The copper content in the shell is 3.8%-4.9%.

4. A cylindrical battery cell as claimed in claim 1, characterized in that: The thickness of the UV adhesive protective layer is 18-22 μm.

5. A cylindrical battery cell as claimed in claim 1, characterized in that: The thickness of the UV adhesive protective layer is 20 μm.

6. A cylindrical battery cell as claimed in claim 1, characterized in that: The UV glue is evenly sprayed on the inner side of the shell to form a UV glue protective layer.

7. A cylindrical battery cell as claimed in claim 1, characterized in that: The chemical composition and content of 2 series aluminum alloy are: Cu3.8%-4.9%, Mn0.30%-1.0%, Mg1.2%-1.8%, Cr0.10%, Si0.50%, Zn0.25%, and the balance is Al.

8. A battery, characterized in that: It comprises a cylindrical battery cell as described in any one of claims 1 to 7.

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