A battery

Abstract

The application relates to the technical field of new energy batteries, and discloses a battery, which comprises a battery cell assembly, a connecting sheet and a tab, the battery cell assembly comprises a battery cell body and the tab, the tab is arranged on at least one end of the battery cell body along a first direction, the connecting sheet is arranged on one side of the battery cell body along the first direction, the connecting sheet comprises a first area and a second area, the first area is used for being connected with a material plate, the second area is provided with the first area on an edge in a second direction, the tab is wound from the battery cell body to the second area on a side of the second area which is away from the battery cell body along the first direction, at least a part of the tab is covered on and connected to a surface of the second area which is away from the battery cell body, and a part of the tab is located on at least one side of the connecting sheet along the second direction; wherein the tab and the first area do not completely overlap in a third direction. The application can reduce the risk of cutting of the tab by the first area, thereby ensuring the overcurrent capacity between the tab and the battery cell body and reducing the possibility of abnormal heating of the tab caused by blocked current transmission.

Description

Technical Field

[0001] This invention relates to the field of new energy battery technology, and in particular to a battery. Background Technology

[0002] In traditional battery manufacturing processes, the tabs and connectors are typically welded by fixing the tabs to the lower surface of the connector. This connection method results in a large gap in the height direction between the connector and the cell assembly, leading to low internal space utilization and limiting the improvement of battery energy density. To improve the space utilization in the height direction, the tabs are currently bent above the connector for welding. However, this structural arrangement affects the current transmission performance between the tabs and the cell assembly, causing the tabs to overheat and potentially even triggering thermal runaway. Summary of the Invention

[0003] The purpose of this invention is to provide a battery that reduces the risk of the tabs being cut and improves battery safety.

[0004] To achieve the above objectives, the present invention provides a battery comprising:

[0005] A battery cell assembly includes a battery cell body and a tab, the tab being disposed on at least one end of the battery cell body along a first direction;

[0006] A connecting piece is disposed on one side of the cell body along the first direction. The connecting piece includes a first region and a second region. The first region is disposed on the edge of the second region in the second direction. The electrode extends from the cell body to the second region along the first direction away from the cell body. At least a portion of the electrode covers and is connected to the surface of the second region away from the cell body. A portion of the electrode is located on at least one side of the connecting piece along the second direction.

[0007] Wherein, the electrode tab and the first region do not completely overlap in the third direction;

[0008] The first direction, the second direction, and the third direction intersect each other.

[0009] This invention provides a battery, which has the following advantages compared with the prior art:

[0010] The battery of the present invention includes a cell assembly and a connecting piece, a cell body and a tab disposed on the cell body, the connecting piece including a second region and a first region disposed on the second region, the first region and the tab being disposed on the same side of the second region, and the first region and the tab not completely overlapping, which can reduce the overlapping area between the tab and the first region, reduce the contact area between the tab and the first region, and even the first region and the tab being spaced apart and not in contact with each other, thereby reducing the risk of the first region cutting the tab, thereby ensuring the overcurrent capacity between the tab and the cell body, reducing the possibility of abnormal heating of the tab due to current transmission obstruction, thereby reducing the occurrence of battery thermal runaway and improving battery safety. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the internal structure of the battery according to an embodiment of the present invention.

[0012] Figure 2 yes Figure 1 Enlarged diagram of point A in the middle.

[0013] Figure 3 yes Figure 1 Sectional view at point CC.

[0014] Figure 4 yes Figure 3 Enlarged diagram of point E in the middle.

[0015] Figure 5 This is a schematic diagram of the internal structure of a battery according to another embodiment of the present invention.

[0016] Figure 6 yes Figure 5 Enlarged diagram of point B in the middle.

[0017] Figure 7 yes Figure 5 Sectional view at point DD.

[0018] Figure 8 yes Figure 7 Enlarged schematic diagram at point F in the middle.

[0019] Figure 9 yes Figure 7 An enlarged schematic diagram of the first region of another implementation at point F.

[0020] Figure 10 This is a schematic diagram of the connecting piece in an embodiment of the present invention.

[0021] Figure 11 yes Figure 10 An enlarged schematic diagram of point G in the diagram.

[0022] In the diagram, 1 is the battery cell assembly; 2 is the connecting piece; 11 is the battery cell body; 12 is the electrode tab; 21 is the second zone; 22 is the first zone; 211 is the electrode tab connection part; 212 is the electrode post connection part; Z is the first direction; Y is the second direction; X is the third direction. Detailed Implementation

[0023] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0024] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, 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 invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0027] Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] A battery according to an embodiment of the present invention includes: a cell assembly 1 and a connecting piece 2.

[0029] The battery cell assembly 1 includes a battery cell body 11 and a tab 12, with the tab 12 disposed on at least one end of the battery cell body 11 along a first direction X.

[0030] The battery cell body 11 includes a separator and two types of electrodes with opposite polarities, namely a positive electrode and a negative electrode. It operates by the movement of metal ions between the positive and negative electrodes. The cycling process of the battery cell body 11 is the process of metal ions moving from the positive electrode to the negative electrode and then from the negative electrode to the positive electrode. Each electrode includes a current collector and an active material layer, with the active material layer coated on the surface of the current collector. The tab serves as the current output terminal of the battery cell, and it can be integrally connected to the positive or negative electrode or connected separately. The connection point between the active material layer on the current collector and the tab is the root of the tab. If the electrode is a positive electrode, the current collector material can be aluminum, and the active material layer material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. If the electrode is a negative electrode, the current collector material can be copper, and the active material layer material can be carbon or silicon, etc.

[0031] In this embodiment, the height direction of the battery casing is the first direction X, the width direction of the battery casing is the second direction Y, and the length direction of the battery casing is the third direction X. The first direction X, the second direction Y, and the third direction X intersect each other in pairs, and in this embodiment, they are set to be perpendicular to each other, which means that the angle is between 85° and 95°.

[0032] Both the cell assembly 1 and the connecting piece 2 are located in the battery casing.

[0033] The battery cell assembly 1 also includes tabs 12, which are electrically connected to the electrode plates. Specifically, the positive tab 12 is electrically connected to the positive electrode plate, and the negative tab 12 is electrically connected to the negative electrode plate. The battery cell body 11 is charged and discharged through the positive and negative tabs 12. The tabs 12 are components formed by stacking and connecting the uncoated positive electrode active material layers on the electrode plates, and are used to connect the battery terminals.

[0034] The connecting piece 2 is disposed on one side of the cell body 11 along the first direction X. The connecting piece 2 includes a second region 21 and a first region 22. The first region 22 is used to connect with the material plate. The first region 22 is disposed on the edge of the second region 21 in the second direction Y. The tab 12 extends from the cell body 11 to the second region 21 along the first direction X away from the cell body 11. At least a portion of the tab 12 covers and is connected to the surface of the second region 21 away from the cell body 11. A portion of the tab 12 is located on at least one side of the connecting piece 2 along the second direction Y.

[0035] Please refer to Figure 10 and Figure 11 The connecting piece 2 facilitates the connection of the tab 12 to the terminal post, enabling external devices to connect to the electrical wiring inside the battery casing via the terminal post. Connecting pieces 2 are typically used separately for connections between tabs 12 and terminals of different polarities.

[0036] In this embodiment, according to Figure 1In the view shown, the connecting piece 2 is positioned above the cell body 11. In order to improve the space utilization of the battery in the height direction, the tab 12 is bent from between the connecting piece 2 and the cell body 11, passing through one side of the connecting piece 2 and extending above the connecting piece 2. The tab 12 covering the connecting piece 2 is welded to the upper surface of the connecting piece 2.

[0037] The second zone 21 is the body of the connecting piece 2, and the first zone 22 is the material-carrying point on the connecting piece 2, which is the structure left over from the cutting of the connecting piece 2 for connecting the material plate.

[0038] The electrode 12 and the first region 22 do not completely overlap in the third direction X.

[0039] Incomplete overlap; it could be that tab 12 and section 22 partially overlap. Please refer to [reference needed]. Figure 5 and Figure 6 Alternatively, the tab 12 and the first zone 22 can be spaced apart on the third direction X. Please refer to [reference needed]. Figure 1 and Figure 2 .

[0040] Due to manufacturing limitations, before the connecting piece 2 is completely cut from the material plate, there are material-carrying points on its outer edge. These material-carrying points, which are part of the first area 22 in this embodiment, are the locations used for connection with the material plate. In the prior art, these material-carrying points are completely covered by the tab 12, which can easily cut the tab 12, affecting the current transmission performance between the tab 12 and the cell assembly 1, causing the tab 12 to overheat, and even triggering battery thermal runaway.

[0041] This structure reduces the overlap between the tab 12 and the first region 22, reduces the contact area between the tab 12 and the first region 22, and even allows the first region 22 and the tab 12 to be spaced apart and not in contact with each other, thereby reducing the risk of the first region 22 cutting the tab 12. This ensures the overcurrent capacity between the tab 12 and the cell body 11, reduces the possibility of abnormal heating of the tab 12 due to obstructed current transmission, and thus reduces the occurrence of battery thermal runaway and improves battery safety.

[0042] In some embodiments, please refer to Figure 7 and Figure 8 The tab 12 and the first region 22 partially overlap in the third direction X, and the overlap distance between the tab 12 and the first region 22 in the third direction X is a mm, satisfying: 0.5≤a≤8. Preferably, a can take values ​​such as 0.2, 0.5, 1, 2.5, 4.1, 6, 8, 8.3, etc.

[0043] Due to manufacturing processes, the first zone 22 has more burrs than the second zone 21. When value 'a' meets the aforementioned range, it ensures the current-carrying capacity of the tab 12 while reducing the risk of the tab 12 being cut. If the value is too small, the tab 12 will be smaller, resulting in a smaller connection area with the connecting piece 2 and with the cell body 11, thus affecting the current-carrying performance of the tab 12. If the value is too large, it will increase the overlap between the tab 12 and the first zone 22 in the third direction X, increasing the possibility of contact and raising the risk of the tab 12 being scratched or worn by the first zone 22.

[0044] When measuring dimension a, a general length measuring tool can be used, such as a ruler or tape measure.

[0045] When measuring a, take the end of the tab 12 closest to the first region 22 in the third direction X as the reference edge, and measure the distance between the edge of the first region 22 covered by the tab 12 in the third direction X and the reference edge using a length measuring tool. Take multiple measurements and average the result to obtain the distance a mm of overlap between the tab 12 and the first region 22 in the third direction X.

[0046] The distance of zone 21 in the third direction X is b mm, which satisfies: 0.02 ≤ a / b ≤ 0.3. Optionally, a / b can take values ​​such as 0.01, 0.02, 0.15, 0.27, 0.3, 0.4, etc.

[0047] When a / b meets the above-mentioned range, it ensures that the manufacturing difficulty of the connecting piece 2 is not too high, while also reducing the risk of the tab 12 being cut. If the value is too small, the processing difficulty of the connecting piece 2 increases, making it difficult to control the manufacturing quality of the connecting piece 2, resulting in a decrease in the manufacturing quality of the connecting piece 2, thereby affecting the current carrying capacity of the connecting piece 2 itself. If the value is too large, it will increase the overlap size between the tab 12 and the first region 22 in the third direction X, increasing the possibility of contact, which will lead to an increased risk of the tab 12 being scratched and worn by the first region 22.

[0048] Furthermore, the distance b mm from zone 21 in the third direction X also satisfies: 15 ≤ b ≤ 55. Optionally, b can take values ​​such as 12, 15, 20, 34, 50, 55, 60, etc.

[0049] When the above range is met, it can ensure the welding area of ​​the tab 12, guarantee the current flow capacity between the connecting piece 2 and the tab 12, and also ensure that the manufacturing difficulty of the connecting piece 2 is not too high.

[0050] When measuring dimension b, a general length measuring tool can be used, such as a ruler or tape measure.

[0051] When measuring b, take the connecting piece 2 and use a length measuring tool to measure the distance between the two ends of the second zone 21 in the third direction X. Take multiple measurements and take the average value to obtain the distance b mm of the second zone 21 in the third direction X.

[0052] The distance of the tab 12 in the third direction X is c mm, which satisfies: 0.05 ≤ a / c ≤ 0.3. Optionally, a / c can take values ​​such as 0.036, 0.05, 0.1, 0.21, 0.24, 0.3, 0.312, etc.

[0053] When the a / c value meets the above range, it can ensure the current-carrying capacity of the tab 12 while reducing the risk of the tab 12 being cut. If the value is too small, the size of the tab 12 will decrease, and its connection area with the connecting piece 2 and its connection area with the cell body 11 will also be smaller, affecting the current-carrying performance of the tab 12. If the value is too large, it will increase the overlap between the tab 12 and the first region 22 in the third direction X, increasing the possibility of contact and leading to an increased risk of the tab 12 being scratched or worn by the first region 22.

[0054] Furthermore, the distance of the tab 12 in the third direction X is c mm, satisfying: 15 ≤ c ≤ 85. Optionally, c can take values ​​such as 11, 15, 20, 38, 41, 57, 66, 72, 80, 85, 88, etc.

[0055] When the above range is met, the current carrying capacity will not be affected by the small size of the tab 12, nor will the overlap size with the first region 22 be increased due to the large size of the tab 12, thus reducing the risk of the tab 12 being cut by the first region 22.

[0056] When measuring dimension c, a general length measuring tool can be used, such as a ruler or tape measure.

[0057] When measuring c, the distance between the two ends of the tab 12 in the third direction X is measured using a length measuring tool. The measurement is repeated multiple times and the average value is taken to obtain the distance c mm of the tab 12 in the third direction X.

[0058] In some embodiments, please refer to Figure 3 and Figure 4 The electrode 12 and the first zone 22 are spaced apart on the third direction X.

[0059] The first zone 22 and the tab 12 are spaced apart and do not contact each other, which significantly reduces the risk of the first zone 22 cutting the tab 12, thereby ensuring the overcurrent capacity between the tab 12 and the cell body 11, reducing the possibility of abnormal heating of the tab 12 due to obstructed current transmission, thereby reducing the occurrence of battery thermal runaway and improving battery safety.

[0060] The distance between the tab 12 and the first region 22 in the third direction X is d mm, which satisfies: 0.2≤d≤12. Optionally, d can take values ​​such as 0.1, 0.2, 1, 2.8, 4.7, 6, 8.4, 10, 11.3, 12, 12.5, etc.

[0061] When value d meets the above range, it avoids making the size of tab 12 too small, ensuring the current-carrying capacity of tab 12, while also reducing the risk of tab 12 being cut. If the value is too small, the size of tab 12 decreases, and its connection area with connecting piece 2 and its connection area with cell body 11 are also smaller, affecting the current-carrying performance of tab 12. If the value is too large, the distance between tab 12 and first zone 22 is too close, increasing the risk of tab 12 being cut.

[0062] When measuring dimension d, a general length measuring tool can be used, such as a ruler or tape measure.

[0063] When measuring d, the edge of the first region 22 near the tab 12 in the third direction X is taken as the reference edge. The distance between the edge of the tab 12 near the first region 22 in the third direction X and the reference edge is measured by a length measuring tool. The measurement is repeated multiple times and the average value is taken to obtain the interval distance d mm between the tab 12 and the first region 22 in the third direction X.

[0064] The second region 21 includes a tab connection portion 211 and a pole connection portion 212. At least a portion of the tab 12 covers and is connected to the tab connection portion 211. One end of the tab connection portion 211 in the third direction X is connected to the pole connection portion 212. The first region 22 is disposed on at least one side of the pole connection portion 212 in the second direction Y.

[0065] The tab connection portion 211 is used to cover and weld the tab 12, and the pole post connection portion 212 is used to connect the pole post. In this embodiment, there are two tab connection portions 211 and one pole post connection portion 212. This is because two cell assemblies 1 are provided in this embodiment, and the tab 12 of each cell assembly 1 is connected to one tab connection portion 211. In other embodiments, other numbers of tab connection portions 211 may also be provided.

[0066] The distance of the tab connection 211 in the second direction Y is e mm, which satisfies: 5≤e≤24. Optionally, e can take values ​​of 3, 5, 8, 11, 15, 17, 20, 24, 25, etc.

[0067] When the value e meets the above range, it can ensure the current-carrying capacity between the tab 12 and the connecting piece 2, while reducing the risk of the tab 12 being cut. If the value is too small, the size of the tab connection part 211 will be too small, and its connection area with the tab 12 and its connection area with the cell body 11 will also be small, affecting the current-carrying performance of the tab 12. If the value is too large, the overall size of the tab 12 will be large, which will make the distance between the tab 12 and the first zone 22 closer, increasing the risk of the tab 12 being cut.

[0068] When measuring dimension e, a general length measuring tool can be used, such as a ruler or tape measure.

[0069] When measuring e, take the connecting piece 2 and measure the distance between the two ends of the tab connecting part 211 in the second direction Y using a length measuring tool. Take multiple measurements and take the average value to obtain the distance e mm of the tab connecting part 211 in the second direction Y.

[0070] The overlap distance between the second zone 21 and the tab 12 in the third direction X is f mm, which satisfies: 15≤f≤55. Optionally, f can take values ​​of 13, 15, 20, 36, 49, 50, 55, 57, etc.

[0071] When the above range is met, the second zone 21 and the tab 12 have sufficient welding area, thereby ensuring the current flow capacity between the connecting piece 2 and the tab 12.

[0072] When measuring dimension f, a general length measuring tool can be used, such as a ruler or tape measure.

[0073] When measuring f, first identify the overlapping area between tab 12 and second region 21. Use a length measuring tool to measure the distance between the two ends of the overlapping area in the third direction X. Take multiple measurements and average the result to obtain the overlapping distance f mm between second region 21 and tab 12 in the third direction X.

[0074] In some embodiments, please refer to Figure 8 The first region 22 is located outside the second region 21, and the first region 22 is located at the end edge of the second region 21 in the second direction Y.

[0075] In this embodiment, the shape of the first region 22 is a protrusion on the edge of the second region 21. With this structure, it can be ensured that the connecting piece 2 has sufficient area, the connection area between the tab 12 and the connecting piece 2 and the connection area between the tab 12 and the cell body 11 are guaranteed, the overcurrent capacity between the connecting piece 2 and the tab 12 is guaranteed, and the occurrence of problems such as excessive current density and local overheating caused by insufficient area is reduced.

[0076] The distance of the tab 12 in the third direction X is c mm, which satisfies: 0.05 ≤ a / c ≤ 0.28. Optionally, a / c can take values ​​such as 0.042, 0.05, 0.09, 0.17, 0.21, 0.26, 0.28, 0.29, etc.

[0077] Since the first zone 22 is designed with a raised shape, it is easy to cut the tab 12. When a / c meets the above range, it can ensure the current carrying capacity of the tab 12 while reducing the risk of the tab 12 being cut.

[0078] In some embodiments, please refer to Figure 9 The first region 22 is located within the second region 21, and the first region 22 is located at the end edge of the second region 22 in the second direction Y.

[0079] In this embodiment, the first region 22 is shaped as a recess on the edge of the second region 21. This structure can reduce the risk of cutting the tab 12 more than the first region 22 being a convex shape.

[0080] The distance of the tab 12 in the third direction X is c mm, which satisfies: 0.07≤a / c≤0.3. Optionally, a / c can take values ​​such as 0.05, 0.07, 0.11, 0.16, 0.21, 0.24, 0.3, 0.35, etc.

[0081] Due to the shape of the recess in the first region 22, although the risk of cutting the tab 12 is reduced, it will also lead to the material deficiency in the second region 21 itself, affecting the connection area between the tab 12 and the connecting piece 2 as well as the connection area between the tab 12 and the cell body 11. When a / c meets the above range, while reducing the risk of cutting the tab 12, the current carrying capacity between the tab 12 and the connecting piece 2 can also be guaranteed.

[0082] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A battery, characterized in that, include: A battery cell assembly includes a battery cell body and a tab, the tab being disposed on at least one end of the battery cell body along a first direction; A connecting piece is disposed on one side of the battery cell body along the first direction. The connecting piece includes a body and a first region. The first region is disposed on the edge of the body of the connecting piece in a second direction. The shape of the first region is either a protrusion on the edge of the body of the connecting piece or a recess on the edge of the body of the connecting piece. The electrode extends from the cell body to the side of the connecting piece away from the cell body along the first direction, with at least a portion of the electrode covering and connected to the surface of the connecting piece away from the cell body, and a portion of the electrode located on at least one side of the connecting piece along the second direction; and, The electrode tab and the first region do not completely overlap in the third direction, and the electrode tab and the first region are spaced apart in the third direction. The distance between the electrode tab and the first region in the third direction is d mm, which satisfies: 0.2≤d≤12. The height direction of the battery casing is the first direction, the width direction of the battery casing is the second direction, and the length direction of the battery casing is the third direction. The first direction, the second direction, and the third direction intersect each other.

2. The battery according to claim 1, characterized in that: The electrode tab overlaps with the first region in the third direction, and the distance between the overlap of the electrode tab and the first region in the third direction is a mm, satisfying: 0.5≤a≤8.

3. The battery according to claim 2, characterized in that: The distance between the body of the connecting piece and the third direction is b mm, satisfying: 0.02≤a / b≤0.

3.

4. The battery according to claim 2, characterized in that: The distance between the tabs in the third direction is c mm, which satisfies: 0.05≤a / c≤0.

3.

5. The battery according to claim 1, characterized in that: The body of the connecting piece includes a tab connecting part and a pole connecting part. At least a portion of the tab covers and is connected to the tab connecting part. The tab connecting part is connected to the pole connecting part at one end in the third direction. The first area is disposed on at least one side of the pole connecting part along the second direction. The distance between the tab connection portion and the second direction is e mm, which satisfies: 5≤e≤24.

6. The battery according to claim 1, characterized in that: The overlap distance between the body of the connecting piece and the electrode in the third direction is f mm, which satisfies: 15≤f≤55.

7. The battery according to claim 2, characterized in that: The first region is located outside the body of the connecting piece, and the first region is located at the end edge of the body of the connecting piece in the second direction.

8. The battery according to claim 7, characterized in that: The distance between the electrode tabs in the third direction is c mm, which satisfies: 0.05≤a / c≤0.

28.

9. The battery according to claim 2, characterized in that: The first region is located within the body of the connecting piece, and the first region is located at the end edge of the body of the connecting piece in the second direction.

10. The battery according to claim 7, characterized in that: The distance between the electrode tabs in the third direction is c mm, which satisfies: 0.07≤a / c≤0.3.

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