Battery and battery pack

Abstract

The present invention relates to the technical field of batteries, and discloses a battery and a battery pack, the battery comprises: a pole having a welding surface; the connecting sheet is attached to the welding surface and is welded with the welding surface to form a welding mark; the capacity of the battery is A, the maximum charge-discharge rate of the battery is C, the overcurrent capacity of a welding mark passing current is K, the current passing area required by the battery is S, the effective area of the welding mark is S0, and the requirement of # imgabs0 is met. In order to guarantee the overcurrent capacity of the welding mark, the effective area of the welding mark cannot be smaller than the current passing area required by the battery; a certain safety margin can be set for the effective area of the welding mark, so that the welding mark is further ensured to have enough overcurrent capability, the welding failure caused by the fact that the welding mark exceeds the welding surface of the pole during welding due to the overlarge effective area of the welding mark is avoided, and the welding failure caused by the overlarge area of the required welding surface due to the overlarge effective area of the welding mark is also avoided. And the overall weight of the battery is overlarge due to the overlarge size of the pole.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to batteries and battery packs. Background Art

[0002] A battery generally includes an external battery structure and an internal battery structure. The external battery structure includes components such as a shell and a cover plate. The shell and the cover plate are connected to enclose and form a closed space. The internal battery structure includes components such as a pole group. The pole group is arranged in the above-mentioned closed space. The shell and / or the cover plate are provided with poles, which are electrically connected to the pole group, and the poles can be connected to external electrical or conductive components to achieve current transmission inside and outside the battery. With the increasing application of power batteries in vehicles, users have an increasing demand for fast charging of batteries. Therefore, the requirements for the overcurrent capacity of the connection between the pole group and the pole during the use of the battery are getting higher and higher. However, the structural design of the pole also has an important impact on the weight of the battery and the layout of the remaining components. Therefore, while improving the overcurrent capacity of the pole, the structural size of the pole should also be considered. Summary of the Invention

[0003] In view of this, the present invention provides a battery and a battery pack to solve the problem in the prior art that the pole cannot take into account both overcurrent capability and lightweight design.

[0004] In a first aspect, the present invention provides a battery comprising: a terminal having a welding surface; a connecting piece, arranged in contact with the welding surface and welded to form a weld mark; wherein the capacity of the battery is A, the maximum charge and discharge rate of the battery is C, the current flow capacity of the weld mark is K, the current flow area required by the battery is S, the effective area of the weld mark is S0, and the battery meets the following requirements: The unit of A is Ah, the unit of C is 1 / h, and the unit of K is A / mm 2 , the unit of S is mm 2 , the unit of S0 is mm 2 .

[0005] Beneficial effect: In order to ensure the overcurrent capacity of the weld mark, the effective area of the weld mark cannot be less than the current flow area required by the battery, and a certain safety margin can be set for the effective area of the weld mark. While further ensuring that the weld mark has sufficient overcurrent capacity, it avoids the effective area of the weld mark being too large, which may cause the weld mark to exceed the welding surface of the pole during welding and cause welding failure. It also avoids the effective area of the weld mark being too large, which may cause the area of the required welding surface to be too large, thereby causing the pole to be too large and the overall weight of the battery to be too large.

[0006] In an optional embodiment, the effective length of the weld mark is P, the effective weld width of the weld mark is W0, and the number of weld marks is n, satisfying S0=P×W0×n, where P is in mm, W0 is in mm, and n is a positive integer.

[0007] In an optional embodiment, when the weld mark is a strip structure, the effective length of the weld mark is the total length of the weld mark; or, when the weld mark is a ring structure, the effective length of the weld mark is the circumference of the ring structure at the midpoint of the effective weld width of the weld mark.

[0008] In an optional embodiment, the effective length P of the weld mark satisfies 10 mm ≤ P ≤ 100 mm; and / or the effective weld width W0 of the weld mark satisfies 1.0 mm ≤ W0 ≤ 4.0 mm.

[0009] In an optional embodiment, the area of the welding surface is S1, which satisfies The unit of S1 is mm 2 .

[0010] Beneficial effect: While ensuring that the welding surface has sufficient area to fully accommodate the weld mark, it avoids the excessive size of the electrode caused by the welding surface being too large, thereby meeting the lightweight design of the battery.

[0011] In an optional embodiment, the minimum distance between the outer edge of the weld mark and the edge of the weld surface is x, and x≥2 mm.

[0012] Beneficial effect: A certain safety distance is reserved between the outer edge of the weld mark and the edge of the weld surface to avoid welding slag splashing and / or the weld mark exceeding the edge of the pole, thereby preventing the parts around the pole from being ablated.

[0013] In an optional embodiment, a plurality of weld marks are arranged at intervals on the welding surface, and a distance y between two adjacent weld marks satisfies y≥1.5 mm.

[0014] Beneficial effect: A certain safety distance is reserved between adjacent weld marks to avoid overlapping of adjacent weld marks and causing welding problems such as weld penetration.

[0015] In an optional embodiment, the maximum charge and discharge rate C of the battery satisfies 1≤C≤8.

[0016] In an optional embodiment, the battery further includes a pole group body, the pole group body includes a pole tab, and the pole tab is welded to the connecting piece.

[0017] In a second aspect, the present invention further provides a battery pack comprising the above-mentioned battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 Schematic diagram of the structure of the first type of pole and weld mark according to an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the structure of the second type of pole and weld mark according to an embodiment of the present invention;

[0021] Figure 3 Schematic diagram of the structure of the third type of pole and weld mark according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic structural diagram of a rectangular ring structure weld print according to an embodiment of the present invention;

[0023] Figure 5 This is a structural diagram of a circular ring structure weld print according to an embodiment of the present invention;

[0024] Figure 6 Schematic diagram of the welding structure of the connecting piece and the pole according to an embodiment of the present invention;

[0025] Figure 7 Schematic diagram of the pole, connecting piece and welding stamp structure of an embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 1. Pole; 11. Welding surface; 2. Connecting piece; 3. Welding mark; 4. Cover plate. DETAILED DESCRIPTION

[0028] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0029] The following combination Figures 1 to 7 , describing embodiments of the present invention.

[0030] According to an embodiment of the present invention, on the one hand, a battery is provided, comprising: a terminal 1 having a welding surface 11; a connecting piece 2, which is arranged in contact with the welding surface 11 and welded to form a weld mark 3; wherein the capacity of the battery is A, the maximum charge and discharge rate of the battery is C, the current flow capacity of the weld mark 3 is K, the current flow area required by the battery is S, and the effective area of the weld mark 3 is S0, satisfying The unit of A is Ah, the unit of C is 1 / h, and the unit of K is A / mm 2 , the unit of S is mm 2 , the unit of S0 is mm 2 .

[0031] In order to ensure the overcurrent capacity of the weld mark 3, the effective area of the weld mark 3 cannot be smaller than the current flow area required by the battery. In addition, a certain safety margin can be set for the effective area of the weld mark 3. While further ensuring that the weld mark 3 has sufficient overcurrent capacity, it can also avoid the effective area of the weld mark 3 being too large, which may cause the weld mark 3 to exceed the welding surface 11 of the electrode 1 during welding and cause welding failure. It can also avoid the effective area of the weld mark 3 being too large, which may cause the area of the required welding surface 11 to be too large, thereby causing the size of the electrode 1 to be too large and the overall weight of the battery to be too large.

[0032] It is worth noting that the current flow area S required by the battery is the minimum effective area of the weld mark 3 that meets the overcurrent capability of the battery, that is, the effective area S0 of the weld mark 3 needs to be at least S, that is, it is necessary to make S0 ≥ S; however, when the effective area S0 of the weld mark 3 is larger, the area of the welding surface 11 needs to be larger in order to accommodate the weld mark 3, which will lead to a larger size of the pole 1, and further lead to a larger overall weight of the battery, which is not conducive to the lightweight design of the battery. Therefore, in this embodiment, the current flow area S required by the battery and the effective area S0 of the weld mark 3 are made to meet That is, S≤S0≤1.3S, taking into account both the overcurrent capability of the pole 1 and the lightweight design of the battery.

[0033] It should be further explained that the current flow area S required by the battery is related to the battery's own parameters (battery capacity A, battery's maximum charge and discharge rate C, and the current flow capacity K of weld mark 3). Battery capacity is one of the important performance indicators for measuring battery performance. It represents the amount of electricity discharged by the battery under certain conditions (discharge rate, temperature, termination voltage, etc.). The battery capacity is generally related to the amount of active material in the battery and the utilization rate of the active material. The more active material there is, the higher the active material utilization rate, and the greater the battery capacity. The battery's charge and discharge rate refers to the current required for the battery to discharge its rated capacity within a specified time. In terms of data value, it is equal to a multiple of the battery's rated capacity, that is, charge and discharge rate = charge and discharge current / rated capacity. The current flow capacity K of weld mark 3 is related to the material of pole 1. Different materials of pole 1 have different current flow capacities. Common pole 1 materials are usually copper, aluminum, or copper-aluminum composite structures. For aluminum pole 1, the current flow capacity K of weld mark 3 is 8A / mm. 2 For the copper pole 1, the current capacity of the welding mark 3 is K = 10A / mm 2 .

[0034] It is worth noting that the battery of this embodiment can be a battery of various structural forms, such as a square battery, a blade battery, a cylindrical battery, etc. The larger the battery capacity, the greater the current passing through the electrode 1 per unit time. Therefore, the weld 3 connecting the electrode 1 and the connecting piece 2 requires a larger current flow area to provide a larger current transmission path.

[0035] In one embodiment, the maximum charge and discharge rate C of the battery satisfies 1≤C≤8. Preferably, the maximum charge and discharge rate C of the battery satisfies 1≤C≤5.

[0036] In one embodiment, the effective area S0 of the weld mark 3 can be calculated based on the effective length of the weld mark 3, the effective weld width of the weld mark 3, and the number of weld marks 3. Specifically, the effective length of the weld mark 3 is P, the effective weld width of the weld mark 3 is W0, and the number of weld marks 3 is n, satisfying S0=P×W0×n, where P is in mm, W0 is in mm, and n is a positive integer.

[0037] It is worth noting that if Figure 6 As shown, the effective weld width of weld mark 3 is the weld width corresponding to the joint between the welding surface 11 of the electrode 1 and the connecting piece 2. The effective weld width of weld mark 3 can be obtained by metallographic measurement of a cross section of the electrode 1 and the connecting piece 2 at weld mark 3.

[0038] Further, such as Figures 1 to 5As shown, the shape of the weld mark 3 can be a strip structure or an annular structure (e.g., a circular ring, a rectangular ring, etc.). When the weld mark 3 is a strip structure, the effective length of the weld mark 3 is the total length of the weld mark 3; or, when the weld mark 3 is an annular structure, the effective length of the weld mark 3 is the circumference of the annular structure at the midpoint of the effective weld width of the weld mark 3.

[0039] Specifically, such as Figure 1 As shown, the weld mark 3 is a strip structure, and the effective length P of the weld mark 3 is equal to the length L of the weld mark 3, that is, P = L. Figure 5 As shown, the weld mark 3 is a circular ring structure, the inner radius of the circular ring structure is r, and the effective length of the weld mark 3 is P = 2×π×(r+W0 / 2). Figure 4 As shown, the weld mark 3 is a rectangular ring structure, the inner circle length of the rectangular ring structure is L1, and the width is L2. The effective length P of the weld mark 3 is 2×(L1+W0)+2×(L2+W0).

[0040] It is worth noting that the welding mark 3 can be set to one or more, that is, n=1, or n=2, or n=3... and so on.

[0041] In one embodiment, the effective length P of the weld mark 3 satisfies 10 mm ≤ P ≤ 100 mm.

[0042] In one embodiment, the actual width of the weld mark 3 may fluctuate due to factors such as different welding equipment and welding parameters. The effective weld width W0 of the weld mark 3 satisfies 1.0 mm ≤ W0 ≤ 4.0 mm. Furthermore, the effective weld width of the weld mark 3 also varies depending on the material of the terminal 1. Specifically, for an aluminum terminal 1, the effective weld width is preferably 1.5 mm ≤ W0 ≤ 3.5 mm; for a copper terminal 1, the effective weld width is preferably 1.5 mm ≤ W0 ≤ 3.0 mm.

[0043] In one embodiment, the area of the welding surface 11 is S1, which satisfies The unit of S1 is mm 2 This arrangement ensures that the welding surface 11 has a sufficient area to fully accommodate the welding mark 3 while avoiding the excessive size of the electrode 1 caused by the welding surface 11 being too large, thereby meeting the lightweight design of the battery.

[0044] It is worth noting that if If the value is too small, during actual welding, the welding surface 11 of the pole 1 cannot accommodate all the weld marks 3, or the weld marks 3 may be offset in position and / or have size deviations, which may cause the weld marks 3 to exceed the welding surface 11 of the pole 1, resulting in poor welding and burnout of parts around the pole 1. If the value of is too large, the area of the welding surface 11 will be too large, which will lead to an excessively large size of the electrode 1 and an excessively large overall weight of the battery.

[0045] It should be noted that if Figures 1 to 3 As shown, the pole 1 is typically in the form of a circular cylinder or a square cylinder, so that the welding surface 11 is typically a circular surface or a square surface. The area of the welding surface 11 is the area of the circular surface or the area of the square surface. Of course, the pole 1 can also have other regular or irregular shapes. The surface of the pole 1 used for welding to the connecting piece 2 is the welding surface 11. After the welding surface 11 is determined, the area of the welding surface 11 can be calculated based on the shape of the welding surface 11.

[0046] In one embodiment, Figures 1 to 3 As shown, the minimum distance x between the outer edge of the weld mark 3 and the edge of the welding surface 11 satisfies x ≥ 2 mm. This arrangement provides a safe distance between the outer edge of the weld mark 3 and the edge of the welding surface 11 to prevent welding slag splashing and / or the weld mark 3 extending beyond the edge of the electrode 1, which could cause ablation of surrounding components of the electrode 1.

[0047] It is worth noting that the pole 1 and the connecting piece 2 are laser welded. The laser of the welding equipment usually acts on the pole 1 through a protective copper nozzle. If the distance between the outer edge of the weld mark 3 and the edge of the welding surface 11 is too small, the welding slag during the welding process is likely to splash onto the surrounding parts of the pole 1, and the weld mark 3 is likely to exceed the edge of the welding surface 11, causing the surrounding parts of the pole 1 to be burned.

[0048] In one embodiment, Figure 1 As shown, a plurality of weld marks 3 are spaced apart on the welding surface 11, and the distance between two adjacent weld marks 3 is y, satisfying y ≥ 1.5 mm. This arrangement reserves a certain safety distance between adjacent weld marks 3 to prevent overlapping of adjacent weld marks 3 and causing welding problems such as weld penetration.

[0049] In one embodiment, the battery further includes a pole group body, the pole group body includes a pole ear, and the pole ear is welded to the connecting piece 2, such as Figure 7 As shown, the connecting piece 2 is welded to the pole 1 to form a weld mark 3 on the welding surface 11. That is, the pole tab and the pole 1 are transferred through the connecting piece 2.

[0050] It should be noted that the battery further includes a cover plate 4 and a housing. The housing is open at at least one end. The cover plate 4 is connected to the housing and seals the opening. The terminal 1 is disposed on the cover plate 4 and / or the housing. In this embodiment, while ensuring that the weld mark 3 has sufficient overcurrent capacity, the structural dimensions of the terminal 1 are controlled to prevent the excessive size of the terminal 1 from affecting the arrangement of other components on the cover plate 4 and / or the housing.

[0051] The actual overcurrent capability of batteries with different terminal posts 1 and weld marks 3 was tested and evaluated below. The terminal post 1 was made of aluminum. The test results for the example batteries are shown in Table 1, and the test results for the comparative example batteries are shown in Table 2. The example batteries refer to batteries that meet the requirements of this example, while the comparative example batteries refer to batteries that do not meet the requirements of this example.

[0052] Table 1 Test results of battery of embodiment of aluminum pole 1

[0053]

[0054] Table 2 Test results of comparative battery with aluminum pole 1

[0055]

[0056] As can be seen from Table 1, in Examples 1 to 6, the current passing area S required by the battery and the effective area S0 of the weld mark 3 meet The weld mark 3 can meet the use requirements of the current; at the same time, the effective area S0 of the weld mark 3 and the area S1 of the welding surface 11 meet The weld mark 3 can be completely arranged within the welding surface 11; and the pole 1 has an appropriate size, so that the battery can meet the lightweight design requirements.

[0057] Comparing Table 2 with Table 1, it can be concluded that, compared with Example 1, the effective length P of the weld mark 3 in Comparative Example 1 is smaller, and accordingly, the effective area S0 of the weld mark 3 is also smaller, while the capacity A of the battery and the maximum charge and discharge rate C of the battery remain unchanged. Therefore, the current required by the battery to pass through the area S does not change, resulting in The value of is less than 1, which makes the effective area of weld mark 3 too small to meet the overcurrent requirement.

[0058] Comparing Table 2 with Table 1, it can be concluded that the value of the battery capacity A in Comparative Example 2 is larger than that in Example 2. Accordingly, the value of the current passing area S required by the battery is also larger, while the values of the effective length P of the weld mark 3, the effective weld width W0 of the weld mark 3, and the number n of the weld marks 3 remain unchanged. Therefore, the value of the effective area S0 of the weld mark 3 remains unchanged, resulting in The value of is less than 1, which makes the effective area of weld mark 3 too small to meet the overcurrent requirement.

[0059] Comparing Table 2 with Table 1, it can be concluded that the value of the maximum charge and discharge rate C of the battery in Comparative Example 3 is larger than that in Example 3. Accordingly, the value of the current passing area S required by the battery is also larger, while the effective length P of the weld mark 3, the effective weld width W0 of the weld mark 3, and the number n of the weld marks 3 are all unchanged. Therefore, the value of the effective area S0 of the weld mark 3 is unchanged, resulting in The value of is less than 1, which makes the effective area of weld mark 3 too small to meet the overcurrent requirement.

[0060] Comparing Table 2 with Table 1, it can be concluded that, compared with Example 4, the effective length P of the weld mark 3 in Comparative Example 4 is larger, and accordingly, the effective area S0 of the weld mark 3 is also larger, while the capacity A of the battery and the maximum charge and discharge rate C of the battery do not change. Therefore, the value of the current passing through the area S required by the battery does not change, resulting in The value of is greater than 1.3, which makes the flow capacity of weld mark 3 too redundant.

[0061] Comparing Table 2 with Table 1, it can be concluded that in Comparative Example 5, the effective weld width W0 of weld mark 3 is smaller than that of Example 5. Accordingly, the effective area S0 of weld mark 3 is also smaller, while the capacity A of the battery and the maximum charge and discharge rate C of the battery remain unchanged. Therefore, the current required by the battery to pass through the area S remains unchanged, resulting in The value of is less than 1, which makes the effective area of weld mark 3 too small to meet the overcurrent requirement.

[0062] Comparing Table 2 with Table 1, it can be concluded that in Comparative Example 6, the effective weld width W0 of weld mark 3 is larger than that in Example 6. Accordingly, the effective area S0 of weld mark 3 is also larger, while the capacity A of the battery and the maximum charge and discharge rate C of the battery remain unchanged. Therefore, the current required by the battery to pass through the area S remains unchanged, resulting in The value of is greater than 1.3, which makes the flow capacity of the weld mark 3 too much; and since the value of the area S1 of the weld surface 11 does not change, The value of is less than 1.2, so that the weld mark 3 is welded to the edge of the pole 1, causing the surrounding insulating plastic to melt and affect the insulation performance.

[0063] The actual overcurrent capability of batteries with different electrode posts 1 and weld marks 3 was tested and evaluated below, where the electrode post 1 was made of copper. The test results for the example batteries are shown in Table 3, and the test results for the comparative example batteries are shown in Table 4. The example batteries refer to batteries that meet the requirements of this example, while the comparative example batteries refer to batteries that do not meet the requirements of this example.

[0064] Table 3 Test results of the battery of the embodiment of copper electrode 1

[0065]

[0066] Table 4 Test results of the comparative battery with copper electrode 1

[0067]

[0068] It can be seen from Table 3 that in Examples 7 to 12, the current passing area S required by the battery and the effective area S0 of the weld mark 3 meet The weld mark 3 can meet the use requirements of the current; at the same time, the effective area S0 of the weld mark 3 and the area S1 of the welding surface 11 meet The weld mark 3 can be completely arranged within the welding surface 11; and the pole 1 has an appropriate size, so that the battery can meet the lightweight design requirements.

[0069] Comparing Table 4 with Table 3, it can be concluded that, compared with Example 7, the effective length P of the weld mark 3 in Comparative Example 7 is smaller, and accordingly, the effective area S0 of the weld mark 3 is also smaller, while the capacity A of the battery and the maximum charge and discharge rate C of the battery remain unchanged. Therefore, the current required by the battery to pass through the area S does not change, resulting in The value of is less than 1, which makes the effective area of weld mark 3 too small to meet the overcurrent requirement.

[0070] Comparing Table 4 with Table 3, it can be concluded that in Comparative Example 8, the effective weld width W0 of weld mark 3 is smaller than that in Example 8. Accordingly, the effective area S0 of weld mark 3 is also smaller, while the capacity A of the battery and the maximum charge and discharge rate C of the battery remain unchanged. Therefore, the current required by the battery to pass through the area S remains unchanged, resulting in The value of is less than 1, which makes the effective area of weld mark 3 too small to meet the overcurrent requirement.

[0071] Comparing Table 4 with Table 3, it can be concluded that the value of the battery capacity A in Comparative Example 9 is larger than that in Example 9. Accordingly, the value of the current passing area S required by the battery is also larger, while the effective length P of the weld mark 3, the effective weld width W0 of the weld mark 3, and the number n of the weld marks 3 are all unchanged. Therefore, the value of the effective area S0 of the weld mark 3 is unchanged, resulting in The value of is less than 1, which makes the effective area of weld mark 3 too small to meet the overcurrent requirement.

[0072] Comparing Table 4 with Table 3, it can be concluded that the value of the maximum charge and discharge rate C of the battery in Comparative Example 10 is larger than that in Example 10. Accordingly, the value of the current passing area S required by the battery is also larger, while the effective length P of the weld mark 3, the effective weld width W0 of the weld mark 3, and the number n of the weld marks 3 are all unchanged. Therefore, the value of the effective area S0 of the weld mark 3 is unchanged, resulting in The value of is less than 1, which makes the effective area of weld mark 3 too small to meet the overcurrent requirement.

[0073] Comparing Table 4 with Table 3, it can be concluded that in Comparative Example 11, the effective weld width W0 of weld mark 3 is larger than that in Example 11. Accordingly, the effective area S0 of weld mark 3 is also larger, while the capacity A of the battery and the maximum charge and discharge rate C of the battery remain unchanged. Therefore, the current required by the battery to pass through the area S remains unchanged, resulting in The value of is greater than 1.3, which makes the flow capacity of the weld mark 3 too much; and since the value of the area S1 of the weld surface 11 does not change, The value of is less than 1.2, so that the weld mark 3 is welded to the edge of the pole 1, causing the surrounding insulating plastic to melt and affect the insulation performance.

[0074] Comparing Table 4 with Table 3, it can be concluded that, compared with Example 12, the effective length P of the weld mark 3 in Comparative Example 12 is larger, and accordingly, the effective area S0 of the weld mark 3 is also larger, while the capacity A of the battery and the maximum charge and discharge rate C of the battery do not change. Therefore, the value of the current passing through the area S required by the battery does not change, resulting in The value of is greater than 1.3, which makes the flow capacity of weld mark 3 too redundant.

[0075] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising the above-mentioned battery.

[0076] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: A pole having a welding surface; A connecting piece is arranged in contact with the welding surface and welded to form a weld mark; Among them, the capacity of the battery is A, the maximum charge and discharge rate of the battery is C, the current capacity of the weld print is K, the current passing area required by the battery is S, and the effective area of the weld print is S0, satisfying The unit of A is Ah, the unit of C is 1 / h, and the unit of K is A / mm 2 , the unit of S is mm 2 , the unit of S0 is mm 2 .

2. The battery according to claim 1, characterized in that The effective length of the weld mark is P, the effective weld width of the weld mark is W0, the number of the weld marks is n, and S0=P×W0×n is satisfied, where the unit of P is mm, the unit of W0 is mm, and n is a positive integer.

3. The battery according to claim 2, characterized in that When the weld mark is a strip structure, the effective length of the weld mark is the total length of the weld mark; or, when the weld mark is a ring structure, the effective length of the weld mark is the circumference of the ring structure at the midpoint of the effective weld width of the weld mark.

4. The battery according to claim 2, characterized in that The effective length P of the weld mark satisfies 10 mm ≤ P ≤ 100 mm; and / or the effective weld width W0 of the weld mark satisfies 1.0 mm ≤ W0 ≤ 4.0 mm.

5. The battery according to any one of claims 1 to 4, characterized in that The area of the welding surface is S1, which satisfies The unit of S1 is mm 2 .

6. The battery according to any one of claims 1 to 4, characterized in that The minimum distance between the outer edge of the weld mark and the edge of the weld surface is x, and x≥2mm.

7. The battery according to any one of claims 1 to 4, characterized in that A plurality of weld marks are arranged on the welding surface at intervals, and the distance between two adjacent weld marks is y, which satisfies y≥1.5mm.

8. The battery according to any one of claims 1 to 4, characterized in that The maximum charge and discharge rate C of the battery satisfies 1≤C≤8.

9. The battery according to any one of claims 1 to 4, characterized in that The battery further includes a pole group body, the pole group body includes a pole tab, and the pole tab is welded to the connecting piece.

10. A battery pack, characterized in that: A battery comprising the battery according to any one of claims 1 to 9.

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