Battery

Abstract

The present invention relates to the technical field of new energy batteries, and discloses a battery, which comprises: tabs arranged at at least one end of a battery cell body along a first direction; the switching piece comprises a first connecting part and a second connecting part, the first connecting part is located on one side of the battery cell body in the first direction, the first connecting part is connected with the tab to form a first connecting mark, the second connecting part is located on one side of the battery cell body in the second direction, the first connecting part and the second connecting part are connected with each other, and a transition part is formed at the joint; the pole assembly is connected with the second connecting part; and in the second direction, the size of the transition part is a mm, the distance between the edge of one side, deviating from the battery cell body, of the second connecting part and the first connecting mark is h mm, and h-a is greater than or equal to 1 and less than or equal to 14. According to the battery provided by the invention, by limiting the overcurrent path on the switching piece, the overcurrent requirement is ensured to be met, the heat generation of the overcurrent area is controlled, and the charging and discharging performance of the battery and the safety of the battery are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy batteries, and particularly to a battery. Background Art

[0002] For some batteries, the tabs of the battery cells are located on the side of the battery, while the terminal assembly is located on the top of the battery. The tabs and the terminal assembly are connected by a connecting piece. In this structure, if the battery is charged at a high rate, the heat generation in the current-carrying area of the connecting piece is serious, which affects the charge and discharge performance of the battery. Summary of the Invention

[0003] The object of the present invention is to provide a battery to improve the charge and discharge performance of the battery.

[0004] To achieve the above object, the present invention provides a battery, comprising: A battery cell body; Tabs, which are arranged at at least one end of the battery cell body along a first direction; A connecting piece, which comprises a first connecting portion and a second connecting portion. The first connecting portion is located on one side of the battery cell body in the first direction, the first connecting portion is connected to the tabs and forms a first connection mark, the second connecting portion is located on one side of the battery cell body in a second direction, and the first connecting portion and the second connecting portion are connected to each other and form a transition portion at the connection; A terminal assembly, which is connected to the second connecting portion; Wherein, in the second direction, the size of the transition portion is a mm, and the distance between the plane where the edge of the side of the second connecting portion away from the battery cell body is located and the first connection mark is h mm, satisfying: 1 ≤ h - a ≤ 14.

[0005] The battery provided by the present invention has the following beneficial effects compared with the prior art: The battery of the present invention comprises a battery cell body, tabs, a connecting piece and a terminal assembly. The tabs are arranged on the battery cell body. The connecting piece comprises a first connecting portion and a second connecting portion. The first connecting portion is connected to the tabs to form a first connection mark, and the second connecting portion is connected to the terminal assembly. The first connecting portion and the second connecting portion form a transition portion. By restricting the distance between the first connection mark and the transition portion, the current-carrying path on the connecting piece is restricted, so as to ensure meeting the current-carrying requirement, control the heat generation in the current-carrying area, and improve the charge and discharge performance and the safety of the battery. Brief Description of the Drawings

[0006] Figure 1 It is a schematic structural view of the battery according to an embodiment of the present invention.

[0007] Figure 2It is a schematic diagram of the interior of the battery according to an embodiment of the present invention.

[0008] Figure 3 It is a schematic diagram of the battery cell body and the adapter plate according to an embodiment of the present invention.

[0009] Figure 4 It is Figure 3 an enlarged schematic diagram of part A in

[0010] Figure 5 It is a schematic structural diagram of the adapter plate according to an embodiment of the present invention.

[0011] Figure 6 It is a schematic diagram of an adapter plate according to an embodiment of the present invention.

[0012] Figure 7 It is a schematic diagram of another adapter plate according to an embodiment of the present invention.

[0013] Figure 8 It is a schematic diagram of an adapter plate corresponding to the full tab structure according to an embodiment of the present invention.

[0014] Figure 9 It is a schematic diagram of another adapter plate corresponding to the full tab structure according to an embodiment of the present invention.

[0015] Figure 10 It is a schematic diagram of an adapter plate corresponding to the non-full tab structure according to an embodiment of the present invention.

[0016] Figure 11 It is a schematic diagram of another adapter plate corresponding to the non-full tab structure according to an embodiment of the present invention.

[0017] Figure 12 It is an assembly structure of a tab and an adapter plate according to an embodiment of the present invention.

[0018] Figure 13 It is another assembly structure of a tab and an adapter plate according to an embodiment of the present invention.

[0019] In the figure, 1 is the battery cell body; 2 is the tab; 3 is the adapter plate; 4 is the terminal assembly; 21 is the first connection mark; 22 is the second connection mark; 31 is the first connection part; 32 is the second connection part; 33 is the transition part; X is the first direction; Z is the second direction; Y is the third direction. Detailed Embodiments

[0020] The following will further describe in detail the specific embodiments of the present invention with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0021] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0022] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0024] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Please refer to Figure 1 and Figure 2 , a battery according to an embodiment of the present invention includes a battery cell body 1, a tab 2, a connecting piece 3, and a terminal assembly 4.

[0026] In this embodiment, the battery is a rectangular body, and the housing of the battery is also a rectangular body. A receiving cavity is provided inside the housing for placing the battery cell.

[0027] The tab 2 is provided at at least one end of the battery cell body 1 along the first direction X.

[0028] The battery cell body 1 realizes charge and discharge through a positive tab and a negative tab. The electrode plate includes a current collector and an active material layer, and the active material layer is coated on the surface of the current collector. If the electrode plate is a positive electrode plate, the material of the current collector can be aluminum, and the material of the active material layer can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. If the electrode plate is a negative electrode plate, the material of the current collector can be copper, and the material of the active material layer can be carbon or silicon, etc.

[0029] The first direction X, the second direction Z, and the third direction Y intersect pairwise. In this embodiment, the length direction of the battery is the first direction X, the height direction of the battery is the second direction Z, and the width direction of the battery is the third direction Y. The first direction X, the second direction Z, and the third direction Y are perpendicular to each other pairwise. The perpendicular state refers to the state where the angle is 85° - 95°.

[0030] Please refer to Figure 3 and Figure 4 , the adapter plate 3 includes a first connection portion 31 and a second connection portion 32. The first connection portion 31 is located on one side of the battery cell body 1 in the first direction X. The first connection portion 31 is connected to the tab 2 and forms a first connection mark 21. The second connection portion 32 is located on one side of the battery cell body 1 in the second direction Z. The first direction X and the second direction Z are perpendicular to each other. The first connection portion 31 and the second connection portion 32 are connected to each other and form a transition portion 33 at the connection.

[0031] In this embodiment, please refer to Figure 5 , the adapter plate 3 has an L-shaped structure. Both the first connection portion 31 and the second connection portion 32 are plate-shaped. The transition portion 33 forms an arc-shaped corner of the first connection portion 31 and the second connection portion 32.

[0032] The first connection portion 31 corresponds to the side surface of the battery cell body 1 and is laser welded to the tab 2. The first connection mark 21 is the weld mark formed by welding.

[0033] The terminal assembly 4 is connected to the second connection portion 32.

[0034] The second connection portion 32 corresponds to the top surface of the battery cell body 1. By providing the adapter plate 3, the terminal assembly 4 and the tab 2 are electrically connected.

[0035] The terminal assembly 4 is used to electrically connect the battery to external devices. The terminal assembly 4 is divided into a positive terminal assembly 4 and a negative terminal assembly 4 with different polarities. The positive terminal assembly 4 or the negative terminal assembly 4 of each battery can be provided in multiple numbers. In this embodiment, one positive terminal assembly 4 and one negative terminal assembly 4 are provided respectively. In specific production implementation, the number and position of the electrode column assembly 4 can be set according to needs.

[0036] In the second direction Z, the size of the transition portion 33 is a mm, and the distance between the plane where the edge of the side of the second connection portion 32 facing away from the battery cell body 1 and the first connection mark 21 is h mm, satisfying: 1 ≤ h - a ≤ 14. Preferably, h - a can take values such as 1, 3, 5.5, 8, 10.7, 12, 14, etc.

[0037] By restricting the distance between the first connection pad 21 and the transition portion 33, the overcurrent path on the adapter piece 3 is restricted, ensuring that the overcurrent requirement is met, controlling the heat generation in the overcurrent area, improving the charge and discharge performance of the battery and the battery safety. If the value of h - a is too large, the path between the first connection pad 21 and the terminal assembly 4 is large, and the overcurrent line of the first connection pad 21 on the adapter piece 3 is too long, resulting in serious heat generation of the first connection pad 21, affecting the charge and discharge performance and safety performance of the battery; if the value of h - a is too small, the first connection pad 21 will be too close to the transition portion 33. When welding the electrode tab 2 and the first connection portion 31, the clamping positions of the electrode tab 2 and the first connection portion 31 by the fixture include the transition portion 33, and the clamping positions are not flat, easily leading to defects such as poor welding and hole explosion, affecting the overcurrent capacity between the electrode tab 2 and the terminal assembly 4, and being unfavorable for the overcurrent and safety performance of the battery.

[0038] When measuring the dimensions a and h, common length measuring tools can be used, such as a ruler, a tape measure and other measuring tools.

[0039] Specifically, when measuring a, taking the surface on the side of the second connection portion 32 away from the battery cell body 1 as the reference plane, measure the distance between the reference plane and the edge where the transition portion 33 is connected to the first connection portion 31 along the second direction Z through a length measuring tool, measure multiple times and take the average value to obtain the dimension a mm of the transition portion 33. In the case where the transition portion 33 is set as a 90° arc, a is also the radius of the transition portion 33. In this embodiment, a is still the distance between the two edges of the projection of the transition portion 33 in the second direction Z.

[0040] When measuring h, taking the surface on the side of the second connection portion 32 away from the battery cell body 1 as the reference plane, measure the distance between the reference plane and the edge of the first connection pad 21 close to the terminal assembly 4 along the second direction Z through a length measuring tool, measure multiple times and take the average value to obtain the distance h mm between the edge of the second connection portion 32 away from the battery cell body 1 and the first connection pad 21.

[0041] To support the rationality of the above numerical range, this embodiment also conducts experimental verification on the batteries that meet the above numerical range.

[0042] Test content: Taking the battery of the lithium iron phosphate system as an example, batteries of the same model and batch are selected for testing. Except for different specifications of a selected, the model dimensions of other battery cell structural components are the same.

[0043] Test 1: Welding of the electrode tab 2. Using the conventional laser welding equipment and welding process on the production line, weld the electrode tab 2 to the adapter piece 3. When welding each battery cell assembly, control the welding parameter h respectively. After welding is completed, visually inspect whether there are defects such as poor welding and hole explosion in the welding area.

[0044] Test 2: High-rate battery charge and discharge test. After the cell components are welded in Test 1, they are assembled into the casing, and processes such as injection and formation are completed to form the battery product, and then the finished battery is subjected to charge and discharge tests.

[0045] Test equipment: Charge and discharge tester, constant temperature oven, data acquisition and monitoring system. The test temperature is 25°C.

[0046] Constant current charging: The battery is charged at a current of 4C until the battery voltage reaches the rated charging voltage.

[0047] Constant voltage charging: When the battery voltage reaches the rated charging voltage, it switches to constant voltage charging and stops charging until the charging current drops to 0.05C.

[0048] Discharge process: The battery is discharged at a current of 4C until the battery voltage drops to the rated discharge cut-off voltage.

[0049] During the test, the data acquisition system collects the temperature at the battery terminal and records the highest temperature of each battery terminal during the charging process.

[0050] The normal temperature range is 40°C - 45°C. If it is greater than 45°C, it does not meet the design requirements, indicating that there is serious heat generation in the current transmission path from the terminal to the cell.

[0051] Please refer to Table 1 for the test parameters and index data of each group.

[0052] Table 1 It can be seen that when the h-a of Examples 1 - 22 meets the above range, while ensuring the overcurrent capacity, the battery has good welding quality and does not have serious heat generation problems. There are no welding defects in the welding area of the tab 2, and it passes the high-rate charge and discharge test.

[0053] Among them, for Examples 1 - 3 and Examples 17 - 22, although there are no welding defects in the welding area of the tab 2, and it passes the high-rate charge and discharge test, and the temperature at the terminal is within the design requirements, but each has some process defects.

[0054] For Comparative Examples 1 - 4, there are welding defects in the welding area of the tab 2, and it is found that the terminal temperature exceeds the design range during the charge and discharge test, which proves that the welding quality defect will affect the overcurrent, resulting in abnormal temperature on the overcurrent path.

[0055] For Comparative Examples 5 - 7, there are no welding defects in the welding area of the tab 2, but due to the long overcurrent path, the temperature of the terminal is higher than the design temperature during the battery charge and discharge test.

[0056] In the second direction Z, for a and h, the following conditions are satisfied: 6≤ h ≤14, 1≤ a ≤4.

[0057] Preferably, h can take values ​​such as 6, 8.1, 9.4, 10, 11.8, 13.6, and 14.

[0058] Preferably, a can take values ​​such as 1, 1.5, 2.7, 3.3, 4, etc.

[0059] When the value of h is small, there is equipment interference during the welding process. When the value of h is large, the area on the upper end of the pole ear 2 that is not welded and gathered is large, and there is a problem of bending and wrinkling of the pole ear 2.

[0060] When the value of a is small, the manufacturing process of the battery adapter 3 is difficult. When the value of a is large, the transition portion 33 of the adapter 3 occupies a large space, which affects the overall energy density of the battery.

[0061] In some embodiments, please refer to Figure 3 and Figure 6 In the second direction Z, the edge of the first connection portion 31 away from the second connection portion 32 is flush with the edge of the battery cell body 1 away from the second connection portion 32 .

[0062] In this structure, the adapter plate 3 extends from the top surface of the battery cell body 1 to the bottom surface of the battery cell body 1. The adapter plate 3 has a larger overall area, a larger heat dissipation area, and better heat dissipation performance.

[0063] In the second direction Z, for a and h, the following condition is satisfied: 6≤ h - a ≤ 14. Preferably, ha can take values ​​such as 6, 7.9, 9.1, 11, 12.4, 13.8, 14, etc.

[0064] When ha meets this range, it can meet the overcurrent demand, control the heat generation in the overcurrent area, and improve the battery's charging and discharging performance and battery safety.

[0065] In some embodiments, please refer to Figure 7 In the second direction Z, the size of the adapter 3 is d mm, the size of the battery body 1 is D mm, and the following conditions are satisfied: 1 / 3≤ d / D ≤ 2 / 3, 1≤ h - a ≤ 7. Preferably, ha can be 1, 2.1, 3.7, 5, 6.2, 7, etc.

[0066] When 1 / 3≤ d / D ≤ 2 / 3 is satisfied, the adapter sheet 3 extends from the top surface of the battery cell body 1 to the middle of the battery cell body 1, which simplifies the structure of the adapter sheet 3, reduces the weight of the battery, and allows the battery cell body 1 to enter the shell more easily when the battery cell body 1 enters the shell.

[0067] When measuring d and D, common length measuring tools can be used, such as a ruler, a tape measure and other measuring tools.

[0068] Specifically, when measuring d, taking the surface on the side of the second connecting portion 32 facing away from the battery cell body 1 as the reference plane, measuring the distance between the reference plane and the edge of the first connecting portion 31 far from the second connecting portion 32 along the second direction Z with a length measuring tool, measuring multiple times and taking the average value, the size of the adapter plate 3 is d mm.

[0069] When measuring D, taking either the top surface or the bottom surface of the battery cell body 1 as the reference plane, measuring the distance between the reference plane and the other plane along the second direction Z with a length measuring tool, measuring multiple times and taking the average value, the size of the battery cell body 1 is D mm.

[0070] Since the structure of the adapter plate 3 is simplified, the heat dissipation area of the adapter plate 3 and the reserved welding space are small. When 1 ≤ h - a ≤ 7 is satisfied, it can not only ensure the welding quality of the tab 2 and the first connecting portion 31 and meet the overcurrent requirement, but also control the heat generation in the overcurrent area, improve the charge and discharge performance of the battery and the battery safety.

[0071] In some embodiments, please refer to Figure 8 and Figure 9 , in the second direction Z, both ends of the tab 2 are flush with both ends of the battery cell body 1.

[0072] For this full-tab 2 structure, when forming the tab 2, the tab 2 does not need to be cut.

[0073] Please refer to Figure 8 , the adapter plate 3 extends from the top surface of the battery cell body 1 to the bottom of the battery cell body 1. The adapter plate 3 can better support the tab 2 to prevent the tab 2 from being torn and deformed. The adapter plate 3 also has a large heat dissipation area and can dissipate heat better. Please refer to Figure 9 , the adapter plate 3 extends from the top surface of the battery cell body 1 to the middle of the battery cell body 1. The tab 2 near the bottom of the battery cell body 1 can be folded and attached to the side surface of the battery cell body 1. The simplified adapter plate 3 can make the battery cell body 1 more easily enter the housing and prevent the tab 2 from being wrinkled and broken when entering the housing.

[0074] In some embodiments, please refer to Figure 10 and Figure 11 , in the second direction Z, the tab 2 is located on the center line of the battery cell body 1, and at least one end of the tab 2 has a distance from the corresponding end edge of the battery cell body 1.

[0075] In this embodiment, the center line of the tab 2 coincides with the center line of the battery cell body 1.

[0076] For this non-full tab 2 structure, when forming the tab 2 , the tab 2 needs to be cut and shaped.

[0077] Please refer to Figure 10 The adapter plate 3 extends from the top surface of the battery cell body 1 to the bottom of the battery cell body 1. The adapter plate 3 has a large heat dissipation area and can dissipate heat better. Figure 11 The adapter sheet 3 extends from the top surface of the battery cell body 1 to the middle of the battery cell body 1, and the tab 2 near the bottom of the battery cell body 1 can be retracted and fitted to the side of the battery cell body 1. The simplified adapter sheet 3 can reduce the weight of the battery, and when the battery cell body 1 enters the shell, it can make it easier for the battery cell body 1 to enter the shell.

[0078] In some embodiments, please refer to Figure 3 and Figure 4 The pole ear 2 has a second connection mark 22, the first connection mark 21 is located inside at least one of the second connection marks 22, and in the second direction Z, the distance between the edge of the second connection portion 32 away from the battery body 1 and the first connection mark 21 is L mm, satisfying: 6≤ L - a ≤13. Preferably, La can be 6, 7, 8.3, 10, 11.9, 12.5, 13, etc.

[0079] The second connection mark 22 is a welding mark formed by ultrasonic welding to gather the pole tabs 2, that is, multiple layers of pole tabs 2 are stacked together and ultrasonically welded together to form the second connection mark 22. The pole tabs 2 and the first connecting portion 31 are then welded together to form the first connection mark 21, so as to avoid gaps between the layers of pole tabs 2 leading to poor welding. At the same time, the first connection mark 21 is located inside the second connection mark 22, limiting the distance between the second connection mark 22 and the transition portion 33, and preventing the first connection mark 21 from being too close to the transition portion 33, affecting the overcurrent capacity between the pole tabs 2 and the pole assembly 4, which is not conducive to the overcurrent and safety performance of the battery.

[0080] When measuring dimension L, you can use a common length measuring tool, such as a ruler or tape measure.

[0081] Specifically, when measuring L, the surface of the second connection portion 32 facing away from the battery body 1 is used as the reference plane, and the distance between the reference plane and the edge of the second connection mark 22 close to the pole assembly 4 is measured along the second direction Z by a length measuring tool. The measurement is performed multiple times and the average value is taken to obtain the distance L mm between the edge of the second connection portion 32 facing away from the battery body 1 and the first connection mark 21.

[0082] In the second direction Z, two ends of the pole tab 2 are flush with two ends of the battery cell body 1 , and a plurality of second connection marks 22 are provided and arranged along the second direction Z.

[0083] With such a structure, different positions of the pole tab 2 can be gathered and welded to prevent the pole tab 2 from being scattered and torn. This can ensure the welding quality between the pole tab 2 and the adapter 3 and facilitate the insertion of the battery cell body 1 into the shell.

[0084] The distance between two adjacent second connection marks 22 is t mm, which satisfies: 10≤ t ≤ 40. t can be 10, 15, 21, 26, 31, 33, 39, 40, etc.

[0085] When the above range is met, the tab 2 between two adjacent second connection marks 22 is not easy to tear, thereby improving the yield rate of battery assembly manufacturing.

[0086] When measuring dimension t, you can use a common length measuring tool, such as a ruler or tape measure.

[0087] Specifically, when measuring t, the distance between two opposite edges of two adjacent second connection marks 22 is measured, and the measurement is repeated multiple times and the average value is taken to obtain the distance t mm between the two adjacent second connection marks 22 .

[0088] A first connection mark 21 is disposed inside each second connection mark 22 .

[0089] For the full-ear lug 2 structure, in order to allow the adapter 3 to better support the ear 2, the adapter 3 extends from the top surface of the battery cell body 1 to the bottom of the battery cell body 1, and a first connection mark 21 is set inside each second connection mark 22, which can improve the strength of the ear 2 and better dissipate heat.

[0090] There is a distance between the edge of the first connection portion 31 away from the second connection portion 32 and the edge of the cell body 1 away from the second connection portion 32 , and the first connection mark 21 is disposed inside the second connection mark 22 opposite to the first connection portion 31 .

[0091] For the full-ear tab 2 structure, in order to facilitate the insertion of the battery cell body 1 into the shell, the adapter sheet 3 extends from the top surface of the battery cell body 1 to the middle of the battery cell body 1, so that a part of the ear tab 2 is connected to the adapter sheet 3 to form a first connection mark 21. In other words, the first connection mark 21 is not set inside a part of the second connection mark 22. These second connection marks 22 are close to the bottom of the battery cell body 1. While ensuring the welding strength of the ear tab 2 and the adapter sheet 3 and the heat dissipation capacity of the adapter sheet 3, it can prevent the ear tab 2 from being dispersed and torn, making it easier for the battery cell body 1 to enter the shell.

[0092] In some embodiments, in the third direction Y, the minimum distance between the second connection mark 22 and the edge of the battery body 1 is M mm, satisfying: 2≤ M ≤10. Preferably, M can be 2, 4.4, 5.9, 6.2, 7.7, 8, 9.4, 10, etc.

[0093] If the value of M is too small, the distance between the second connecting tab 22 and the cell body 1 is too small, and the distance from the edge of the first connecting portion 31 is too small, there is a risk of solder pads during the welding of the first connecting tab 21. If the value of M is too large, the size of the second connecting tab 22 itself is too small, which will affect the connection quality when multiple layers of tabs 2 are stacked together.

[0094] When measuring the dimension M, common length measuring tools can be used, such as a ruler or a tape measure.

[0095] Specifically, when measuring M, taking the side surface of the cell body 1 that is closer to the second connecting tab 22 in the third direction Y as the reference plane, use a length measuring tool to measure the distance between the reference plane and the edge of the second connecting tab 22 close to the reference plane along the third direction Y. Measure multiple times and take the average value to obtain the minimum distance M mm between the edge of the second connecting tab 22 and the cell body 1.

[0096] In some embodiments, please refer to Figure 4 and Figure 12 , in the first direction X, at least a part of the tab 2 and the cell body 1 are located on both sides of the first connecting portion 31.

[0097] When the tab 2 and the adapter plate 3 are assembled, the tab 2 will be folded and a part of it will be attached to the surface of the first connecting portion 31 of the adapter plate 3 facing away from the cell body 1, avoiding the folding and tearing of the tab 2 between the adapter plate 3 and the cell body 1, and the welding position is located outside the first connecting portion 31, which is convenient for welding positioning.

[0098] In some embodiments, please refer to Figure 13 , in the first direction X, the tab 2 is located between the first connecting portion 31 and the cell body 1.

[0099] When the tab 2 and the adapter plate 3 are assembled, the tab 2 will be folded and a part of it will be attached to the surface of the first connecting portion 31 of the adapter plate 3 facing the cell body 1. When inserting into the case, the first connecting portion 31 protects the tab 2 and prevents the tab 2 from being torn.

[0100] In some embodiments, the cell body 1 is a stacked cell. The cell body 1 includes electrode plates and a separator. The electrode plates are stacked layer by layer along the second direction Z, and the separator is disposed between two adjacent electrode plates, and the two adjacent electrode plates are separately provided.

[0101] The cell body 1 includes a separator and two types of electrode plates with opposite polarities, namely a positive electrode plate and a negative electrode plate. The cycling process of the cell is the process of metal ions moving from the positive electrode plate to the negative electrode plate and then from the negative electrode plate to the positive electrode plate.

[0102] The electrode sheets are stacked layer by layer, and the electrode sheets of the same polarity are discontinuous. The separator is arranged between the positive electrode sheet and the negative electrode sheet to form a stacked cell. The electrode assembly further includes tab 2, and tab 2 is electrically connected to the electrode sheet. Among them, the positive tab is electrically connected to the positive electrode sheet, and the negative tab is electrically connected to the negative electrode sheet. The cell body 1 realizes charge and discharge through the positive tab and the negative tab. The electrode sheet includes a current collector and an active material layer, and the active material layer is coated on the surface of the current collector. If the electrode sheet is a positive electrode sheet, the material of the current collector can be aluminum, and the material of the active material layer can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. If the electrode sheet is a negative electrode sheet, the material of the current collector can be copper, and the material of the active material layer can be carbon or silicon, etc.

[0103] Compared with the wound cell, the stacked cell has a higher utilization rate of the internal space of the battery, and the risk of lithium deposition on the battery electrode sheet is relatively small.

[0104] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A battery, characterized in that, Comprising: The battery cell body; The tab, which is arranged at at least one end of the battery cell body along the first direction; The adapter piece, which includes a first connection part and a second connection part. The first connection part is located on one side of the battery cell body in the first direction. The first connection part is connected to the tab and forms a first connection mark. The second connection part is located on one side of the battery cell body in the second direction. The first connection part and the second connection part are connected to each other and form a transition part at the connection; The terminal assembly, which is connected to the second connection part; Wherein, in the second direction, the size of the transition part is a mm, and the distance between the plane where the edge on the side of the second connection part away from the battery cell body is located and the first connection mark is h mm, satisfying: 1 ≤ h - a ≤ 14.

2. The battery according to claim 1, wherein: In the second direction, the size of the transition part is a mm, and the distance between the edge on the side of the second connection part away from the battery cell body and the first connection mark is h mm, and further satisfies: 6 ≤ h ≤ 14, 1 ≤ a ≤ 4.

3. The battery according to claim 1, wherein: In the second direction, the edge on the side of the first connection part away from the second connection part is flush with the edge on the side of the battery cell body away from the second connection part; In the second direction, the size a mm of the transition part and the distance h mm between the edge on the side of the second connection part away from the battery cell body and the first connection mark further satisfy: 6 ≤ h - a ≤ 14.

4. The battery according to claim 1, wherein: In the second direction, the size of the adapter piece is d mm, and the size of the battery cell body is D mm, satisfying: 1 / 3 ≤ d / D ≤ 2 / 3, 1 ≤ h - a ≤ 7.

5. The battery according to any one of claims 1, 3 or 4, wherein: In the second direction, the two ends of the tab are flush with the two ends of the battery cell body.

6. The battery according to any one of claims 1, 3 or 4, wherein: In the second direction, the tab is located on the center line of the battery cell body, and at least one end of the tab has a distance from the corresponding end edge of the battery cell body.

7. The battery according to claim 1, wherein: The tab has a second connection mark, the first connection mark is located inside at least one of the second connection marks. In the second direction, the distance between the edge on the side of the second connection part away from the battery cell body and the first connection mark is L mm, satisfying: 6 ≤ L - a ≤ 13.

8. The battery according to claim 7, wherein: In the second direction, the two ends of the tab are flush with the two ends of the battery cell body, and the second connection marks are arranged in multiple numbers and arranged along the second direction.

9. The battery according to claim 8, wherein: The distance between two adjacent second connection marks is t mm, satisfying: 10 ≤ t ≤ 40.

10. The battery according to claim 8, characterized in that: The first connection mark is arranged inside each of the second connection marks.

11. The battery according to claim 7, characterized in that: There is a distance between an edge of the first connection portion facing away from the second connection portion and an edge of the cell body facing away from the second connection portion, and the first connection mark is disposed inside the second connection mark opposite to the first connection portion.

12. The battery according to claim 7, characterized in that: In the third direction, the minimum distance between the second connection mark and the edge of the battery body is M mm, satisfying: 2≤ M ≤10; The third direction, the second direction and the first direction are perpendicular to each other.

13. The battery according to claim 5, characterized in that: In the first direction, at least a portion of the tab and the battery cell body are located on two sides of the first connecting portion respectively.

14. The battery according to claim 6, characterized in that: In the first direction, at least a portion of the tab and the battery cell body are located on two sides of the first connecting portion respectively.

15. The battery according to claim 5, characterized in that: In the first direction, the tab is located between the first connecting portion and the battery cell body.

16. The battery according to claim 6, characterized in that: In the first direction, the tab is located between the first connecting portion and the battery cell body.

17. The battery according to claim 1, characterized in that: The battery cell body is a laminated battery cell, and the battery cell body includes pole pieces and diaphragms. The pole pieces are stacked in layers along the second direction, and the diaphragm is arranged between two adjacent pole pieces, and the two adjacent pole pieces are arranged separately.

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