Battery cover, battery case, battery, and battery pack

Abstract

The utility model relates to battery technical field discloses a cover plate of battery, the shell of battery, battery and battery group. The cover plate of battery includes: a plurality of board bodies of laminated settings, a plurality of board bodies include the top plate and the bottom plate in the opposite two sides of laminated direction, the top plate includes metal element, metal element includes at least one of aluminium element and copper element, the bottom plate includes titanium element, the outer edge of top plate is located the inside of the outer edge of bottom plate. Utilize the bottom plate containing titanium to play the supporting action, promote the structural strength of cover plate, and then enhance the overall rigidity, can improve the structural stability of battery significantly, the top plate contains copper and / or aluminium, copper and aluminium can all realize high quality connection through laser welding, ultrasonic welding, resistance welding etc. mode, is convenient for when welding busbar in the subsequent, and welding stability is higher, and then improve the welding reliability, enhance current transmission efficiency, improve the overcurrent capacity of cover plate and busbar.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery cover, a battery casing, a battery, and a battery pack. Background Technology

[0002] A rechargeable battery is a type of battery that can recover its performance through a charging process after being discharged. Rechargeable batteries are widely used in consumer electronics (such as mobile phones, tablets, and digital cameras), electric vehicles, energy storage systems, and other fields.

[0003] Battery lightweighting is a crucial direction in current battery technology development, particularly in fields such as electric vehicles, portable electronic devices, and aerospace. With increasing demands for energy efficiency and portability, reducing battery weight while maintaining or increasing its energy density has become a research hotspot.

[0004] The battery includes a casing and a cell housed inside the casing. The casing is made of titanium, and can be referred to as a titanium casing. The titanium casing enables the casing to be lightweight. However, when the titanium casing is used as an electrode output terminal of the battery, the welding effect between the titanium casing and the busbar is poor, which can easily affect the current carrying capacity between the titanium casing and the busbar. Utility Model Content

[0005] In view of this, the present invention provides a battery cover, a battery casing, a battery, and a battery pack to solve the problem of poor welding effect of titanium casing and busbar in the prior art.

[0006] In a first aspect, the present invention provides a cover plate for a battery, comprising: a plurality of plates stacked together, wherein the plurality of plates include a top plate and a bottom plate located on opposite sides in the stacking direction, the top plate comprising a metal element, the metal element including at least one of aluminum and copper, the bottom plate comprising titanium, and the outer edge of the top plate being located inside the outer edge of the bottom plate.

[0007] Beneficial effects: The titanium-containing base plate provides support, enhancing the structural strength of the cover plate and thus improving overall rigidity, which can significantly improve the structural stability of the battery; the top plate contains copper and / or aluminum, both of which can be connected with high quality through laser welding, ultrasonic welding, resistance welding, etc., which facilitates subsequent welding of the busbar, resulting in higher welding stability, thereby improving welding reliability, enhancing current conduction efficiency, and improving the current carrying capacity of the cover plate and busbar.

[0008] Secondly, the present invention also provides a battery casing, including a casing body and the aforementioned cover plate, wherein at least one end of the casing body is provided with an opening, the cover plate is disposed over the opening, the bottom plate is disposed facing the opening, and the top plate is disposed away from the opening.

[0009] Thirdly, this utility model also provides a battery, including: the aforementioned casing.

[0010] Fourthly, this utility model also provides a battery pack, including: a plurality of the above-mentioned batteries and a busbar, wherein the busbar connects two adjacent batteries and is welded to the top plate of the cover plate. Attached Figure Description

[0011] 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.

[0012] Figure 1 This is a perspective view of a battery according to an embodiment of the present utility model;

[0013] Figure 2 for Figure 1 A cross-sectional view of the battery cover shown;

[0014] Figure 3 This is a schematic diagram showing the area of ​​the top plate and bottom plate in an embodiment of the present utility model;

[0015] Figure 4 This is a schematic diagram of the fit between the cover plate and the busbar in an embodiment of the present utility model;

[0016] Figure 5 This is a schematic diagram showing the area of ​​the top plate and the welding area in an embodiment of this utility model.

[0017] Explanation of reference numerals in the attached figures:

[0018] 1. Shell body;

[0019] 2. Cover plate; 201. Top plate; 202. Bottom plate;

[0020] 3. Busbar;

[0021] 4. Welding area. Detailed Implementation

[0022] 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.

[0023] The following is combined with Figures 1 to 5 The following describes embodiments of the present invention.

[0024] According to an embodiment of the present invention, in a first aspect, a battery cover 2 is provided, comprising: a plurality of plates stacked together, the plurality of plates including a top plate 201 and a bottom plate 202 located on opposite sides in the stacking direction, the top plate 201 comprising a metal element, the metal element including at least one of aluminum and copper, the bottom plate 202 comprising titanium, and the outer edge of the top plate 201 being located inside the outer edge of the bottom plate 202.

[0025] It should be noted that the top plate 201 is used for welding with the busbar 3.

[0026] The cover plate 2 of the battery in this embodiment uses a titanium-containing base plate 202 for support, which improves the structural strength of the cover plate 2 and enhances the overall rigidity, thus significantly improving the structural stability of the battery. The top plate 201 contains copper and / or aluminum. Both copper and aluminum can be connected with high quality by laser welding, ultrasonic welding, resistance welding, etc., which makes it easier to weld the busbar 3 later. The welding stability is higher, thereby improving the welding reliability, enhancing the current conduction efficiency, and improving the current carrying capacity of the cover plate 2 and the busbar 3.

[0027] Specifically, in this embodiment, such as Figure 2 As shown, there are two plates, namely a top plate 201 and a bottom plate 202, which are stacked along the thickness direction.

[0028] Of course, in other alternative implementations, there can be more plates, that is, one or more plates can be stacked between the top plate 201 and the bottom plate 202.

[0029] In one embodiment, such as Figure 3 As shown, the cover plate 2 has a plane perpendicular to its thickness direction. The ratio of the projected area S1 of the top plate 201 in the plane to the projected area S2 of the bottom plate 202 in the plane satisfies 0.5≤S1 / S2≤0.9. By controlling S1 / S2 within the above range, the welding area between the cover plate 2 and the busbar 3 is guaranteed, thereby improving the welding strength between the cover plate 2 and the busbar 3 and avoiding the risk of fracture due to insufficient strength at the weld between the cover plate 2 and the busbar 3. The bottom plate 202, as a load-bearing foundation, provides rigid support for the top plate 201, ensuring the support strength of the bottom plate 202 for the top plate 201 and preventing deformation or displacement of the top plate 201 due to external forces (such as vibration, impact, thermal stress), thereby improving the stability, safety and long-term reliability of the overall structure.

[0030] It is worth noting that if the values ​​of S1 / S2 are too small, the setting range of the top plate 201 will be too small, resulting in a small usable area for welding with the busbar 3. This can easily affect the welding strength between the cover plate 2 and the busbar 3, and also affect the flow capacity between them. If the values ​​of S1 / S2 are too large, the setting range of the bottom plate 202 will be too small, resulting in weaker support provided by the bottom plate 202 to the top plate 201, which will affect the overall structural stability and reliability of the cover plate 2.

[0031] Optionally, the value of S1 / S2 can be any one of 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, or 0.9, or a value between any two of these values.

[0032] In one embodiment, such as Figure 2 As shown, the distance L1 between the outer edge of the top plate 201 and the outer edge of the bottom plate 202 satisfies 3.1mm ≤ L1 ≤ 3.7mm. By further controlling L1 within the above range, the welding area between the cover plate 2 and the busbar 3 is guaranteed, thereby improving the welding strength between the cover plate 2 and the busbar 3 and avoiding the risk of breakage due to insufficient strength at the weld between the cover plate 2 and the busbar 3; it can also prevent electrical faults such as short circuits caused by contact between the top plates 201 of two adjacent batteries, thus improving electrical safety.

[0033] It is worth noting that if the value of L1 is too small, the outer edge of the top plate 201 will be too close to the outer edge of the bottom plate 202, causing the top plates 201 of adjacent batteries in the battery pack to be too close together, which may easily lead to electrical faults such as short circuits. If the value of L1 is too large, it will result in the setting range of the top plate 201 being too small, which in turn will result in the available area for welding with the busbar 3 being too small, which may easily affect the welding strength between the cover plate 2 and the busbar 3, and affect the current carrying capacity between the cover plate 2 and the busbar 3.

[0034] Optionally, L1 can be any value from 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, or a value between any two of these values.

[0035] In one embodiment, such as Figure 2As shown, the ratio of the thickness T1 of the top plate 201 to the thickness T2 of the bottom plate 202 satisfies 0.2≤T1 / T2≤0.7. By further controlling T1 / T2 within the above range, the welding strength between the cover plate 2 and the busbar 3 is guaranteed, avoiding the risk of breakage due to insufficient strength at the weld between the cover plate 2 and the busbar 3. The bottom plate 202, as a load-bearing foundation, provides rigid support for the top plate 201, ensuring the support strength of the bottom plate 202 for the top plate 201, and preventing deformation or displacement of the top plate 201 due to external forces (such as vibration, impact, thermal stress), thereby improving the stability, safety and long-term reliability of the overall structure.

[0036] It is worth noting that if the value of T1 / T2 is too small, the top plate 201 may become too thin, resulting in limited weld penetration between the top plate 201 and the busbar 3. This could affect the weld strength between the cover plate 2 and the busbar 3, and consequently, the flow capacity between them. If the value of T1 / T2 is too large, the bottom plate 202 may become too thin, resulting in weaker support provided by the bottom plate 202 to the top plate 201. This would affect the overall stability and reliability of the cover plate 2 structure.

[0037] Optionally, T1 / T2 can be any value from 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, or a value between any two values.

[0038] In one embodiment, such as Figure 2 As shown, the thickness T1 of the top plate 201 satisfies 0.2mm≤T1≤0.4mm. This setting ensures the welding strength between the top plate 201 and the busbar 3 while avoiding any impact on the energy density and lightweight design of the battery.

[0039] It is worth noting that if the value of T1 is too small, the top plate 201 may become too thin, resulting in limited weld penetration between the top plate 201 and the busbar 3. This could affect the weld strength between the cover plate 2 and the busbar 3, and consequently, the current carrying capacity between them. If the value of T1 is too large, it will increase the space occupied by the battery, affecting the battery's energy density, and may also increase the battery's weight, impacting the battery's lightweight design.

[0040] Optionally, T1 can be any value from 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.32mm, 0.35mm, 0.38mm, 0.4mm, or a value between any two of these values.

[0041] In one embodiment, such as Figure 2As shown, the thickness T2 of the base plate 202 satisfies 0.6mm≤T2≤0.8mm. A base plate 202 of suitable thickness can provide sufficient mechanical strength to protect internal components from external physical damage (such as impact, compression, etc.) without excessively increasing weight or size, which helps to improve the overall durability and safety of the battery; at the same time, it controls the space occupied by the base plate 202 to ensure the energy density of the battery.

[0042] It is worth noting that if the value of T2 is too small, the base plate 202 may become too thin, resulting in weak support for the top plate 201 and affecting the overall stability and reliability of the cover plate 2. If the value of T2 is too large, it will increase the space occupied by the battery and affect the energy density of the battery.

[0043] Optionally, T2 can be any value from 0.6mm, 0.62mm, 0.65mm, 0.68mm, 0.7mm, 0.72mm, 0.75mm, 0.78mm, 0.8mm, or a value between any two of these values.

[0044] Specifically, in one embodiment, the mass content of aluminum in the top plate 201 is 90% to 99.99%, and the mass content of titanium in the bottom plate 202 is 90% to 99.99%.

[0045] According to an embodiment of the present invention, in a second aspect, a battery casing is also provided, including a casing body 1 and the aforementioned cover plate 2. At least one end of the casing body 1 has an opening, and the cover plate 2 covers the opening. In this case, the bottom plate 202 faces the opening, and the top plate 201 is disposed away from the opening. That is, the top plate 201 is located outside the bottom plate 202 to facilitate welding of the top plate 201 to the busbar 3.

[0046] Furthermore, in one embodiment, such as Figure 1 As shown, the casing has a cylindrical structure, the outer edge of the cover plate 2 is circular, and the main body 1 is cylindrical. That is, the casing is used in cylindrical batteries.

[0047] According to an embodiment of the present invention, in a third aspect, a battery is also provided, such as... Figure 1 As shown, it includes: the aforementioned housing.

[0048] Specifically, in one embodiment, the battery further includes a battery cell and electrode terminals, which are disposed within the housing and electrically connected. The electrode terminals are also electrically connected to the housing. Furthermore, the housing and busbar 3 are electrically connected to facilitate the transfer of power from the battery cell.

[0049] It is worth noting that the electrode terminals include tabs, and the battery cell is electrically connected to the housing through the tabs. Alternatively, the electrode terminals include tabs and current collectors, with the battery cell electrically connected to the tabs, the tabs electrically connected to the current collectors, and the current collectors electrically connected to the housing.

[0050] According to an embodiment of the present invention, in a fourth aspect, a battery pack is also provided, comprising: a plurality of the above-described batteries and a busbar 5, wherein the busbar 3 connects two adjacent batteries, and the busbar 5 is welded to the top plate 201 of the cover plate 2.

[0051] In one embodiment, such as Figure 4 As shown, the distance L2 between the welding area 4 of the busbar 5 and the cover plate 2 and the outer edge of the top plate 201 is greater than or equal to 3mm, and the thickness T2 of the bottom plate 202 satisfies 0.6mm≤T2≤0.75mm. Maintaining a certain distance between the welding area 4 and the outer edge of the top plate 201 facilitates the setting of welding fixtures during the welding process. However, this reduces the area on the top plate 201 available for welding, resulting in a smaller welding area between the busbar 3 and the top plate 201, thus limiting the current-carrying capacity between the top plate 201 and the busbar 3. Therefore, in this embodiment, the value of the thickness T2 of the bottom plate 202 is further limited, further reducing the thickness of the poorly conductive bottom plate 202, lowering the impedance during current transmission, and improving the current-carrying capacity of the cover plate 2.

[0052] In one embodiment, the busbar 5 comprises aluminum, and the top plate 201 comprises aluminum. The presence of aluminum in both the busbar 5 and the top plate 201 ensures that the current-carrying capacity of the busbar 5 matches that of the cover plate 2, preventing poor current transmission and improving the energy transfer efficiency of the battery.

[0053] In one embodiment, such as Figure 5 As shown, the outer edge of the cover plate 2 is circular, the welding area 4 is arc-shaped, and the battery has a plane perpendicular to the thickness direction of the cover plate 2. The ratio of the projected area S3 of the welding area 4 on the plane to the projected area S1 of the top plate 201 on the plane is less than or equal to 0.1, and the thickness T2 of the bottom plate 202 satisfies 0.6mm ≤ T2 ≤ 0.75mm. Because the welding area between the busbar 3 and the top plate 201 is small, the current-carrying capacity between the top plate 201 and the busbar 3 is poor. Therefore, in this embodiment, the value of the thickness T2 of the bottom plate 202 is further limited, further reducing the thickness of the poorly conductive bottom plate 202, reducing the impedance during current transmission, and improving the current-carrying capacity of the cover plate 2.

[0054] In one embodiment, such as Figure 5As shown, the welding area 4 is located on one side of the radial direction of the cover plate 2, and the thickness T2 of the base plate 202 satisfies 0.65mm≤T2≤0.8mm. In this embodiment, the welding area 4 is eccentrically positioned on the cover plate 2, causing the cover plate 2 to experience concentrated stress during the welding of the busbar 3 and the top plate 201. Therefore, by further controlling T2 within the aforementioned range, it is possible to provide greater rigid support for the top plate 201, ensuring the support strength of the base plate 202 for the top plate 201, thereby improving the stability, safety, and long-term reliability of the overall structure.

[0055] In one embodiment, such as Figure 4 As shown, the weld penetration depth d of the welding area 4 between the busbar 5 and the cover plate 2 is less than the thickness T1 of the top plate 201. By controlling the weld penetration depth between the busbar 5 and the cover plate 2 to be less than the thickness T1 of the top plate 201, it is possible to avoid the top plate 201 being burned through, deformed, or forming holes, which would affect the overall structural strength. It is also possible to avoid poor welding caused by shallow weld penetration, such as incomplete welds, thereby improving welding quality and overall structural strength, and contributing to the stability of electrical connections.

[0056] Furthermore, the casing is located on the outermost side of the battery cell to protect it; the casing material can be, but is not limited to, aluminum, steel, aluminum alloy, etc. Specifically, the casing material can be aluminum-manganese alloy, aluminum-magnesium alloy, stainless steel, nickel-plated steel, carbon steel, titanium, etc.

[0057] Furthermore, the tabs serve as the current output terminals inside the battery cell, and are used for electrical connection with current collectors, etc. The tabs can be cut from the current collector or can be separately formed metal parts. It can be understood that the positive tab is electrically connected to the positive electrode plate in the battery cell, and the negative tab is electrically connected to the negative electrode plate in the battery cell.

[0058] Furthermore, the battery cell includes a positive electrode sheet, a negative electrode sheet, and a separator, with the separator disposed between the positive and negative electrode sheets. The positive electrode sheet, negative electrode sheet, and separator are stacked to form the battery cell. The positive electrode sheet includes a positive current collector and a positive active material layer, and the negative electrode sheet includes a negative current collector and a negative active material layer. There are no particular limitations on the positive current collector, as long as it is conductive and will not cause adverse chemical changes in the battery. For example, it can be made of stainless steel, aluminum, nickel, titanium, sintered carbon, or aluminum or stainless steel with a surface treatment of carbon, nickel, titanium, silver, etc. The negative current collector can be made of copper, stainless steel, nickel, titanium, etc. In a specific embodiment, the positive electrode can be made of aluminum, and the negative electrode can be made of copper. The positive active material layer includes a positive active material, such as nickel-cobalt-manganese ternary materials, lithium iron phosphate materials, lithium manganese iron phosphate materials, etc.; the negative active material layer includes a negative active material, such as artificial graphite, natural graphite, silicon-based materials, etc.

[0059] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cover plate for a battery, characterized in that, include: A plurality of plates are stacked together, the plurality of plates including a top plate (201) and a bottom plate (202) located on opposite sides of the stacking direction, the top plate (201) includes a metal element, the metal element including at least one of aluminum and copper, the bottom plate (202) includes titanium, and the outer edge of the top plate (201) is located inside the outer edge of the bottom plate (202).

2. The cover plate according to claim 1, characterized in that, The cover plate (2) has a plane perpendicular to its thickness direction, and the ratio of the projected area S1 of the top plate (201) in the plane to the projected area S2 of the bottom plate (202) in the plane satisfies 0.5≤S1 / S2≤0.

9.

3. The cover plate according to claim 1, characterized in that, The distance L1 between the outer edge of the top plate (201) and the outer edge of the bottom plate (202) satisfies 3.1mm≤L1≤3.7mm.

4. The cover plate according to claim 1, characterized in that, The ratio of the thickness T1 of the top plate (201) to the thickness T2 of the bottom plate (202) satisfies 0.2≤T1 / T2≤0.

7.

5. The cover plate according to claim 1, characterized in that, The thickness T1 of the top plate (201) satisfies 0.2mm≤T1≤0.4mm, and the thickness T2 of the bottom plate (202) satisfies 0.6mm≤T2≤0.8mm.

6. The cover plate according to claim 1, characterized in that, The aluminum content in the top plate (201) is 90% to 99.99% by mass, and the titanium content in the bottom plate (202) is 90% to 99.99% by mass.

7. A battery casing, characterized in that, The device includes a shell body (1) and a cover plate (2) according to any one of claims 1 to 6. At least one end of the shell body (1) is provided with an opening, the cover plate (2) is provided over the opening, the bottom plate (202) is disposed toward the opening, and the top plate (201) is disposed away from the opening.

8. The housing according to claim 7, characterized in that, The shell has a cylindrical structure, the outer edge of the cover plate (2) is circular, and the shell body (1) is cylindrical.

9. A battery, characterized in that, include: The housing as described in claim 7 or 8.

10. A battery pack, characterized in that, include: The battery and busbar (3) according to multiple claims 9, wherein the busbar (3) connects two adjacent batteries and the busbar (3) is welded to the top plate (201) of the cover plate (2).

11. The battery pack according to claim 10, characterized in that, The distance L2 between the welding area (4) of the busbar (3) and the cover plate (2) and the outer edge of the top plate (201) is greater than or equal to 3mm, and the thickness T2 of the bottom plate (202) satisfies 0.6mm≤T2≤0.75mm.

12. The battery pack according to claim 10, characterized in that, The busbar (3) contains aluminum, and the top plate (201) contains aluminum.

13. The battery pack according to claim 10, characterized in that, The outer edge of the cover plate (2) is circular, the shape of the welding area (4) between the busbar (3) and the cover plate (2) is arc-shaped, the battery has a plane perpendicular to the thickness direction of the cover plate (2), the ratio of the projected area S3 of the welding area (4) on the plane to the projected area S1 of the top plate (201) on the plane is less than or equal to 0.1, and the thickness T2 of the bottom plate (202) satisfies 0.6mm≤T2≤0.75mm.

14. The battery pack according to claim 10, characterized in that, The welding area (4) between the busbar (3) and the cover plate (2) is located on one side of the radial direction of the cover plate (2), and the thickness T2 of the base plate (202) satisfies 0.65mm≤T2≤0.8mm.

15. The battery pack according to claim 10, characterized in that, The welding penetration depth d of the busbar (3) and the cover plate (2) in the welding area (4) is less than the thickness T1 of the top plate (201).

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