Battery casing structure and battery cells

Abstract

This invention belongs to the field of battery technology and discloses a battery casing structure and a battery cell. The battery casing structure includes an outer shell and a cover plate. The outer shell includes a first layer, a second layer, and a third layer arranged sequentially from the inside out. The first and third layers are made of plastic, and the second layer is made of metal. The cover plate includes a fourth layer, a fifth layer, and a sixth layer arranged sequentially from the inside out. The fourth and sixth layers are made of plastic, and the fifth layer is made of metal. The cover plate covers the opening of the outer shell. When the fifth layer is welded to the second layer, the fourth layer can be melted and bonded to the first layer, and the sixth layer can be melted and bonded to the third layer. This battery casing structure has high rigidity, low cost, and good sealing performance, resulting in high safety for the battery cell. The battery cell includes a battery cell and the aforementioned battery casing structure. The battery cell is located inside the outer shell, and the cover plate covers the opening of the outer shell, ensuring high safety for the battery cell.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a battery casing structure and a battery cell. Background Technology

[0002] Lithium-ion batteries are widely used in various industries due to their high energy density, long lifespan, small size, and lack of pollution. Currently, the outer casing of lithium-ion batteries is typically made of three materials: metal, composite aluminum-plastic film, and plastic. While metal casings offer advantages in rigidity, they are susceptible to corrosion from the electrolyte or internal short circuits that could lead to explosions, posing a safety hazard. Plastic casings do not meet rigidity requirements, while aluminum-plastic film has poor scratch resistance, easily damaging the battery and rendering it ineffective.

[0003] Therefore, there is an urgent need to propose a battery casing structure and a battery cell to solve the above problems. Summary of the Invention

[0004] The first objective of this invention is to provide a battery casing structure that is rigid, low in cost, and has good sealing properties, thereby ensuring high safety of the battery cell.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] The battery casing structure includes:

[0007] The outer shell includes a first layer, a second layer, and a third layer arranged sequentially from the inside out. The first layer and the third layer are both made of plastic, and the second layer is made of metal.

[0008] The cover plate includes a fourth layer, a fifth layer, and a sixth layer arranged sequentially from the inside out. The fourth layer and the sixth layer are both made of plastic, and the fifth layer is made of metal. The cover plate covers the opening of the outer shell. When the fifth layer is welded to the second layer, the fourth layer can be melted and bonded to the first layer, and the sixth layer can be melted and bonded to the third layer.

[0009] As an optional technical solution for the battery casing structure, along the direction from the outer casing to the cover plate, the first layer and the second layer both extend beyond the third layer, and the extended portions are respectively the first exposed portion and the second exposed portion; along the direction from the cover plate to the outer casing, the fourth layer and the fifth layer both extend beyond the sixth layer, and the extended portions are respectively the third exposed portion and the fourth exposed portion; the first exposed portion and the second exposed portion are sandwiched between the third exposed portion and the fourth exposed portion, so that the third exposed portion, the first exposed portion, the second exposed portion and the fourth exposed portion are stacked sequentially from the inside to the outside.

[0010] As an optional technical solution for the battery casing structure, the battery casing structure further includes a sealing element, which is arranged around the outer periphery of the fourth exposed portion, and the two ends of the sealing element abut against the ends of the third layer and the sixth layer, respectively.

[0011] As an optional technical solution for battery casing structure, the sealing element is made of plastic.

[0012] As an optional technical solution for the battery casing structure, the sealing element is a plastic ring or a plastic strip.

[0013] As an optional technical solution for the battery casing structure, the width of the first exposed portion, the second exposed portion, the third exposed portion, and the fourth exposed portion all range from 3mm to 4mm.

[0014] As an optional technical solution for the battery casing structure, the cover plate is provided with a first mounting hole, which is used to install a first terminal post; and / or,

[0015] The outer casing has a second mounting hole at the end opposite to the opening, and the second mounting hole is used to install the second pole post.

[0016] As an optional technical solution for the battery casing structure, the cover plate is provided with a first mounting hole for installing a first electrode post, and the first electrode post is provided with a liquid injection hole.

[0017] As an optional technical solution for the battery casing structure, the sixth layer on the cover plate is provided with an avoidance opening, and the fifth layer is provided with explosion-proof grooves at the position corresponding to the avoidance opening.

[0018] The second objective of this invention is to provide a battery cell with high safety.

[0019] To achieve this objective, the present invention adopts the following technical solution:

[0020] A battery cell includes a battery cell and the aforementioned battery casing structure, wherein the battery cell is located inside the casing, and a cover plate is provided over the opening of the casing.

[0021] The beneficial effects of this invention are:

[0022] The battery casing structure provided by this invention includes an outer shell and a cover plate, with the cover plate covering the opening of the outer shell. The outer shell includes a first layer, a second layer, and a third layer. The first and third layers are made of plastic, and the second layer is made of metal. The cover plate includes a fourth layer, a fifth layer, and a sixth layer. The fourth and sixth layers are made of plastic, and the fifth layer is made of metal. That is, both the outer shell and the cover plate are made of both metal and plastic. The intermediate metal layer formed by the second and fifth layers ensures the overall rigidity of the battery casing structure. The inner plastic layer formed by the first and fourth layers isolates the metal layer from the battery cell, thus preventing corrosion of the metal layer or preventing electrical conductivity between the metal layer and the internal battery cell, resulting in high safety. The outer plastic layer formed by the third and sixth layers provides structural support and protection for the metal layer, offering good scratch resistance. Furthermore, the insulation of the outer plastic layer means that the battery casing structure has its own insulating protective layer, eliminating the need for additional plastic sealing and saving costs.

[0023] Secondly, when the fifth layer is welded to the second layer, the fourth layer can be melted and bonded to the first layer, and the sixth layer can be melted and bonded to the third layer. This simplifies assembly and results in a high connection strength and good sealing performance between the outer shell and the cover plate. Attached Figure Description

[0024] Figure 1 This is a cross-sectional view of a battery cell provided in an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 A magnified view of a portion at point A;

[0026] Figure 3 yes Figure 1 A magnified view of the area at point B;

[0027] Figure 4 yes Figure 1 Enlarged view at point C

[0028] Figure 5 yes Figure 1 A magnified view of a portion at point D.

[0029] In the picture:

[0030] 10. Battery cell; 21. First terminal; 22. Second terminal; 30. Insulating ring; 40. Pressure ring; 100. Outer casing; 110. First layer; 111. First exposed portion; 120. Second layer; 121. Second exposed portion; 130. Third layer; 200. Cover plate; 210. Fourth layer; 211. Third exposed portion; 220. Fifth layer; 221. Fourth exposed portion; 230. Sixth layer; 300. Seal. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0032] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0035] This embodiment provides a battery casing structure that is rigid, low in cost, and has good sealing performance, thus ensuring high safety of the battery cells.

[0036] Specifically, such as Figures 1 to 4As shown, the battery casing structure includes an outer casing 100 and a cover plate 200. The outer casing 100 includes a first layer 110, a second layer 120, and a third layer 130 arranged sequentially from the inside out. The first layer 110 and the third layer 130 are both made of plastic, and the second layer 120 is made of metal. The cover plate 200 includes a fourth layer 210, a fifth layer 220, and a sixth layer 230 arranged sequentially from the inside out. The fourth layer 210 and the sixth layer 230 are both made of plastic, and the fifth layer 220 is made of metal. The cover plate 200 covers the opening of the outer casing 100. When the fifth layer 220 is welded to the second layer 120, the fourth layer 210 can be melted and bonded to the first layer 110, and the sixth layer 230 can be melted and bonded to the third layer 130.

[0037] Based on the above design, the outer shell 100 includes a first layer 110, a second layer 120, and a third layer 130. The first layer 110 and the third layer 130 are both made of plastic, while the second layer 120 is made of metal. The cover plate 200 includes a fourth layer 210, a fifth layer 220, and a sixth layer 230. The fourth layer 210 and the sixth layer 230 are both made of plastic, while the fifth layer 220 is made of metal. That is, both the outer shell 100 and the cover plate 200 are made of both metal and plastic. The intermediate metal layer composed of 220 can ensure the overall rigidity of the battery case structure; the inner plastic layer composed of the first layer 110 and the fourth layer 210 can isolate the metal layer and the battery cell 10, thereby preventing corrosion of the metal layer or preventing the metal layer from contacting the internal battery cell 10 and conducting electricity, thus ensuring high safety; the outer plastic layer composed of the third layer 130 and the sixth layer 230 can provide structural support and protection for the metal layer, with good scratch resistance, and the insulation of the outer plastic layer makes the battery case structure have its own insulating protective layer, eliminating the need for plastic sealing protection and saving costs.

[0038] Secondly, when the fifth layer 220 is welded to the second layer 120, the fourth layer 210 and the first layer 110 can be melted and bonded together, and the sixth layer 230 and the third layer 130 can be melted and bonded together. The assembly is simple, and the connection strength between the outer shell 100 and the cover plate 200 is high and the sealing performance is good.

[0039] It should be noted that the first layer 110 of the outer shell 100 and the fourth layer 210 of the cover plate 200 may be made of the same material or different materials, as long as they are corrosion-resistant plastic materials; hereinafter, they are collectively referred to as the inner plastic layers. The second layer 120 of the outer shell 100 and the fifth layer 220 of the cover plate 200 may be made of the same material or different materials; hereinafter, they are collectively referred to as metal layers, which are usually made of stainless steel or aluminum.

[0040] The thickness of conventional metal casings, taking stainless steel as an example, is generally 0.3mm-0.5mm, and for aluminum, it is generally between 0.8mm-1.2mm. However, the thickness of the metal layer in this battery structure is one-third of the thickness of a conventional metal casing, reducing the weight of the battery casing structure. The third layer 130 of the outer shell 100 and the sixth layer 230 of the cover plate 200 can be made of the same material or different materials; hereinafter, they are collectively referred to as the outer plastic layer.

[0041] In this embodiment, the outer plastic layer is made of flame-retardant insulating plastic material, which can prevent the battery cells from catching fire.

[0042] There are several ways to manufacture the three-layer structure of the battery casing 100 and the cover plate.

[0043] Optionally, an organic special coating is applied to both the inside and outside of the metal layer to form an inner plastic layer and an outer plastic layer, respectively.

[0044] Alternatively, the metal layer can be bonded together with the injection-molded inner and outer plastic layers by adhesive bonding.

[0045] Optionally, an organic special coating is applied to the inside of the metal layer to form an inner plastic layer; the metal layer is then bonded together with the injection-molded outer plastic layer by adhesive bonding.

[0046] Optionally, an organic special coating is applied to the outside of the metal layer to form an outer plastic layer; the metal layer is then bonded together with the injection-molded inner plastic layer by adhesive bonding.

[0047] Optionally, along the direction from the outer shell 100 to the cover plate 200, the first layer 110 and the second layer 120 both extend beyond the third layer 130, with the extended portions being the first exposed portion 111 and the second exposed portion 121, respectively. Along the direction from the cover plate 200 to the outer shell 100, the fourth layer 210 and the fifth layer 220 both extend beyond the sixth layer 230, with the extended portions being the third exposed portion 211 and the fourth exposed portion 221, respectively. The first exposed portion 111 and the second exposed portion 121 are sandwiched between the third exposed portion 211 and the fourth exposed portion 221, such that the third exposed portion 211, the first exposed portion 111, the second exposed portion 121, and the fourth exposed portion 221 are sequentially stacked from the inside out. When the second exposed portion 121 and the fourth exposed portion 221, which are metal layers, are stacked and welded, the first exposed portion 111 and the third exposed portion 211 located inside the second exposed portion 121 can be fused together. Therefore, while the metal layer lamination welding of the battery casing structure increases the connection strength between the outer casing 100 and the cover plate 200, the lamination and melting of the inner plastic layer can increase the sealing performance between the outer casing 100 and the cover plate 200.

[0048] Furthermore, along the direction from the outer shell 100 to the cover plate 200, the first exposed portion 111 and the second exposed portion 121 extend to abut against the fifth layer 220, increasing the connection and sealing between the outer shell 100 and the cover plate 200.

[0049] Furthermore, the inner side of the first exposed portion 111, that is, the side of the first exposed portion 111 facing the fourth layer 210, is provided with an inclined surface, so that the thickness of the first exposed portion 111 gradually decreases along the direction from the shell to the cover plate 200.

[0050] The width of the first exposed portion 111, the second exposed portion 121, the third exposed portion 211, and the fourth exposed portion 221 all range from 3mm to 4mm. For example, it can be 3mm, 3.5mm, or 4mm. If the width is too small, i.e., less than 3mm, the overlapping area is too small, and the welding area is insufficient; if the width is too large, i.e., greater than 4mm, the overlapping area is too large, resulting in material waste.

[0051] Furthermore, the sealing element 300 is arranged around the outer periphery of the fourth exposed portion 221, and the two ends of the sealing element 300 abut against the ends of the third layer 130 and the sixth layer 230 respectively, thereby increasing the sealing performance between the outer shell 100 and the cover plate 200.

[0052] Furthermore, the seal 300 is made of plastic material. When the metal layers are laminated and welded, the seal 300 can be fused and connected with the third layer 130 and the sixth layer 230, which facilitates the connection between the third layer 130 and the seal 300.

[0053] Specifically, the seal 300 can be a plastic ring or a plastic strip.

[0054] Optionally, the cover plate 200 is provided with a first mounting hole for installing the first pole post 21, that is, holes are made on the fourth layer 210, the fifth layer 220 and the sixth layer 230 to avoid this.

[0055] Optionally, such as Figure 5 As shown, the outer casing 100 has a second mounting hole at one end away from the opening. The second mounting hole is used to install the second pole post 22. That is, holes are opened on the first layer 110, the second layer 120 and the third layer 130 to avoid this opening. The holes are the first hole, the second hole and the third hole, respectively.

[0056] In this embodiment, the insulating ring 30 is located inside the third hole and the second hole, with its two ends respectively wrapping around the outer peripheral edges of the two ends of the third hole, and the outer wall of the end of the insulating ring 30 facing the cell 10 abutting against the inner wall of the second hole; the pressure ring 40 is sleeved on the second pole post 22, with part of the pressure ring 40 located between the insulating ring 30 and the first layer 110, and part of the pressure ring 40 located between the inner ring of the insulating ring 30 and the side wall of the second pole post 22. The insulating ring 30 and the pressure block cooperate to realize the installation of the second pole post 22.

[0057] Optionally, the insulating ring 30 has a protrusion on the side facing the battery cell 10, and the first layer 110 has a groove on the side away from the battery cell 10. The shape of the groove matches the shape of the protrusion, and the protrusion can be inserted and snapped into the groove. A portion of the outer wall of the pressure ring 40 abuts against the inner side of the protrusion.

[0058] Optionally, one of the outer sidewall of the insulating ring 30 and the inner sidewall of the third hole is provided with a buckle, and the other is provided with a groove. The shape of the buckle is adapted to the shape of the groove, and the buckle can be engaged with the groove to improve the installation strength of the insulating ring 30.

[0059] Optionally, since the overall wall thickness of the cover plate 200 and the outer shell 100 is relatively thin, the injection hole is opened on the second pole post 22.

[0060] Optionally, the sixth layer 230 on the cover plate 200 is provided with a clearance opening, and the fifth layer 220 is provided with explosion-proof grooves at the corresponding positions of the clearance opening. That is, a through hole is provided on the sixth layer 230 to avoid the first mounting hole so as to expose the metal layer of the fifth layer 220. The explosion-proof grooves are directly provided to manufacture the explosion-proof valve on the battery shell structure, eliminating the need for secondary welding of the explosion-proof valve.

[0061] This embodiment also provides a battery cell with high safety.

[0062] Specifically, the battery cell includes a battery cell 10 and the aforementioned battery casing structure. The battery cell 10 is located inside the outer casing 100, and the cover plate 200 covers the opening of the outer casing 100. Both the outer casing 100 and the cover plate 200 are made of metal and plastic. The intermediate metal layer composed of the second layer 120 and the fifth layer 220 ensures the overall rigidity of the battery casing structure. The inner plastic layer composed of the first layer 110 and the fourth layer 210 isolates the metal layer from the battery cell 10, thereby preventing corrosion of the metal layer or preventing the metal layer from contacting the internal battery cell 10 and conducting electricity, resulting in high safety. The outer plastic layer composed of the third layer 130 and the sixth layer 230 provides structural support and protection for the metal layer, has good scratch resistance, and the insulation of the outer plastic layer makes the battery casing structure have its own insulating protective layer, eliminating the need for further plastic sealing protection and saving costs. Furthermore, when the cover plate 200 is placed on the outer casing 100 to encapsulate the battery cell 10, the fifth layer 220 is welded to the second layer 120, and the fourth layer 210 is melted and bonded to the first layer 110. This simplifies assembly and ensures that the connection between the outer casing 100 and the cover plate 200 is strong and has good sealing performance.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery casing structure, characterized in that, include: The outer shell (100) includes a first layer (110), a second layer (120) and a third layer (130) arranged sequentially from the inside to the outside. The first layer (110) and the third layer (130) are both made of plastic, and the second layer (120) is made of metal. The cover plate (200) includes a fourth layer (210), a fifth layer (220), and a sixth layer (230) arranged sequentially from the inside to the outside. The fourth layer (210) and the sixth layer (230) are both made of plastic, and the fifth layer (220) is made of metal. The cover plate (200) covers the opening of the outer shell (100). Along the direction from the outer shell (100) to the cover plate (200), the first layer (110) and the second layer (120) extend beyond the third layer (130), and the extended portions are respectively the first exposed portion (111) and the second exposed portion. Part (121), along the direction from the cover plate body (200) to the outer shell body (100), the fourth layer (210) and the fifth layer (220) are both provided beyond the sixth layer (230), and the extended parts are the third exposed part (211) and the fourth exposed part (221) respectively. The first exposed part (111) and the second exposed part (121) are sandwiched between the third exposed part (211) and the fourth exposed part (221), so that the third exposed part (211), the first exposed part (111), the second exposed part (121) and the fourth exposed part (221) are stacked sequentially from the inside to the outside; When the fifth layer (220) is welded to the second layer (120), the fourth layer (210) can be melted and bonded to the first layer (110).

2. The battery casing structure according to claim 1, characterized in that, The battery casing structure also includes a sealing element (300), which is arranged around the outer periphery of the fourth exposed portion (221), and the two ends of the sealing element (300) abut against the ends of the third layer (130) and the sixth layer (230), respectively.

3. The battery casing structure according to claim 2, characterized in that, The seal (300) is made of plastic.

4. The battery casing structure according to claim 3, characterized in that, The sealing element (300) is a plastic ring or a plastic strip.

5. The battery casing structure according to claim 1, characterized in that, The width of the first exposed portion (111), the second exposed portion (121), the third exposed portion (211), and the fourth exposed portion (221) all range from 3mm to 4mm.

6. The battery casing structure according to claim 1, characterized in that, The cover plate (200) is provided with a first mounting hole for mounting a first pole post (21); and / or, The outer casing (100) has a second mounting hole at one end away from the opening, and the second mounting hole is used to install the second pole post (22).

7. The battery casing structure according to claim 6, characterized in that, The cover plate (200) is provided with a first mounting hole, which is used to install a first pole post (21), and the first pole post (21) is provided with a liquid injection hole.

8. The battery casing structure according to claim 1, characterized in that, The sixth layer (230) on the cover plate (200) is provided with a clearance opening, and the fifth layer (220) is provided with explosion-proof markings at the position corresponding to the clearance opening.

9. A single battery cell, characterized in that, The battery includes a battery cell (10) and a battery casing structure according to any one of claims 1-8, wherein the battery cell (10) is located inside the casing (100) and the cover plate (200) covers the opening of the casing (100).

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