Battery

Abstract

The utility model relates to the technical field of batteries, and provides a battery which comprises a battery cell, and the battery cell comprises a battery cell main body; the tab comprises a plurality of single tab layers, and the plurality of single tab layers comprise a first single tab layer and a second single tab layer; wherein the vertical distance between the connecting end and the free end of the first single tab layer is not greater than the vertical distance between the connecting end and the free end of other single tab layers, and the vertical distance between the connecting end and the free end of the second single tab layer is not less than the vertical distance between the connecting end and the free end of other single tab layers; the vertical distance a between the free end of the first single tab layer and the free end of the second single tab layer is 1mm-10mm, so that the distance between the first single tab layer and the second single tab layer can be prevented from being too large, and the first single tab layer can have a reliable welding area during subsequent tab welding, so that the welding quality of tabs is ensured, and the production efficiency is improved. Therefore, the safe use performance of the battery is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery. Background Art

[0002] In the related art, a battery may include a cell, and a tab of the cell may be composed of a plurality of monolithic tab layers, that is, a plurality of monolithic tab layers are stacked to form a tab, and the tab may be used to be electrically connected to a pole assembly, thereby forming a charge and discharge terminal. When the plurality of monolithic tab layers are converged and shaped, unevenness may occur between the ends of the monolithic tab layers, which may affect the subsequent welding quality of the tab. Utility Model Content

[0003] The utility model provides a battery to improve the use performance of the battery.

[0004] The utility model provides a battery, including a battery cell, the battery cell including:

[0005] Battery cell body;

[0006] The tabs extend from the battery body, and the tabs include a plurality of monolithic tab layers, each of which includes a connection end connected to the battery body and a free end away from the battery body, and the plurality of monolithic tab layers include a first monolithic tab layer and a second monolithic tab layer;

[0007] In the direction in which the monolithic tab layer extends from the battery body, the vertical distance between the connection end and the free end of the first monolithic tab layer is not greater than the vertical distance between the connection end and the free end of the other monolithic tab layers, the vertical distance between the connection end and the free end of the second monolithic tab layer is not less than the vertical distance between the connection end and the free end of the other monolithic tab layers, and the vertical distance a between the free end of the first monolithic tab layer and the free end of the second monolithic tab layer is 1 mm-10 mm;

[0008] Among them, a weld mark is formed on the pole ear, and along the extension direction of the second monolithic pole ear layer, the distance between the free end of the second monolithic pole ear layer and the weld mark is d, the free end of the first monolithic pole ear layer is located on the side of the weld mark away from the battery body, the free end of the first monolithic pole ear layer is spaced from the weld mark, and along the extension direction of the first monolithic pole ear layer, the distance between the free end of the first monolithic pole ear layer and the weld mark is e, d / e≤40.

[0009] The battery of the utility model embodiment includes a battery cell, and the battery cell includes a battery cell body and a tab extending from the battery cell body, and the tab is formed by stacking a plurality of monolithic tab layers, thereby ensuring that the battery cell has reliable electrical performance and that the current carrying capacity of the tab itself is also guaranteed. The plurality of monolithic tab layers include a first monolithic tab layer and a second monolithic tab layer, and the vertical distance between the connection end and the free end of the first monolithic tab layer is not greater than the vertical distance between the connection end and the free end of the other monolithic tab layers, and the vertical distance between the connection end and the free end of the second monolithic tab layer is not less than the vertical distance between the connection end and the free end of the other monolithic tab layers, that is, the vertical distance between the free end of the first monolithic tab layer and the free end of the second monolithic tab layer is the farthest between the multiple free ends of the multiple monolithic tab layers, and the free end of the first monolithic tab layer and the second monolithic tab layer are the longest between the multiple free ends of the multiple monolithic tab layers. The vertical distance a between the free ends of the tab layers is 1mm-10mm, thereby avoiding the distance between the two being too large. When the tabs are subsequently welded, the first single-piece tab layer can be guaranteed to have a reliable welding area, thereby ensuring the welding quality of the tabs, and further ensuring the safe performance of the battery. The ratio of the distance d between the free end of the second single-piece tab layer and the weld mark to the distance e between the free end of the first single-piece tab layer and the weld mark is less than or equal to, which can avoid the tab being too long, thereby improving the space utilization rate during battery assembly, thereby effectively improving the performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to better understand the present disclosure, reference may be made to the embodiments shown in the following drawings. The components in the drawings are not necessarily to scale, and related elements may be omitted in order to emphasize and clearly illustrate the technical features of the present disclosure. In addition, related elements or components may have different arrangements as known in the art. In addition, in the drawings, the same reference numerals represent the same or similar components in each drawing. Among them:

[0011] Figure 1 is a schematic structural diagram of a battery according to an exemplary embodiment;

[0012] Figure 2 is a schematic structural diagram of a battery cell according to a first exemplary embodiment;

[0013] Figure 3 is a schematic structural diagram of a battery cell according to a second exemplary embodiment;

[0014] Figure 4 is a schematic structural diagram of a battery cell according to a third exemplary embodiment;

[0015] Figure 5 is a schematic structural diagram of a battery cell according to a fourth exemplary embodiment.

[0016] The following are the descriptions of the reference numerals:

[0017] 10. Battery cell; 11. Battery cell body; 12. Tab; 121. First monolithic tab layer; 122. Second monolithic tab layer; 123. Connecting end; 124. Free end; 125. Third monolithic tab layer; 126. Fourth monolithic tab layer; 1261. Bend section; 13. Weld mark; 14. Depression; 20. Insulating layer; 30. Battery case; 40. Post assembly. DETAILED DESCRIPTION

[0018] The following will be combined with the accompanying drawings in the exemplary embodiments of the present disclosure to clearly and completely describe the technical solutions in the exemplary embodiments of the present disclosure. The exemplary embodiments described herein are only for illustrative purposes and are not intended to limit the scope of protection of the present disclosure. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the scope of protection of the present disclosure.

[0019] In the description of the present disclosure, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more; the term "and / or" includes any and all combinations of one or more associated listed items. In particular, reference to "the / the" object or "an" object is also intended to indicate one of a possible plurality of such objects.

[0020] Unless otherwise specified or explained, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0021] Further, in the description of the present disclosure, it should be understood that the directional words such as "upper", "lower", "inner", "outer" and the like described in the exemplary embodiments of the present disclosure are described at the angles shown in the accompanying drawings and should not be understood as limitations on the exemplary embodiments of the present disclosure. It should also be understood that, in the context, when it is mentioned that an element or feature is connected to another element (one or more) "upper", "lower", or "inner", "outer", it can not only be directly connected to the other (one or more) elements "upper", "lower", "inner", "outer", but also can be indirectly connected to the other (one or more) elements "upper", "lower", "inner", "outer" through an intermediate element.

[0022] An embodiment of the present invention provides a battery. Figures 1 to 5 The battery includes a battery cell 10, and the battery cell 10 includes: a battery cell body 11; a pole ear 12, the pole ear 12 extends from the battery cell body 11, and the pole ear 12 includes a plurality of monolithic pole ear layers, each monolithic pole ear layer includes a connection end 123 connected to the battery cell body 11 and a free end 124 away from the battery cell body 11, and the plurality of monolithic pole ear layers include a first monolithic pole ear layer 121 and a second monolithic pole ear layer 122; in the direction in which the monolithic pole ear layers extend from the battery cell body 11, a vertical distance between the connection end 123 and the free end 124 of the first monolithic pole ear layer 121 is not greater than a vertical distance between the connection end 123 and the free end 124 of other monolithic pole ear layers, and a vertical distance between the connection end 123 and the free end 124 of the second monolithic pole ear layer 122 is not less than a vertical distance between the connection end 123 and the free end 124 of other monolithic pole ear layers. The vertical distance between the connecting end 123 and the free end 124 of the ear layer, and the vertical distance a between the free end 124 of the first monolithic pole ear layer 121 and the free end 124 of the second monolithic pole ear layer 122 is 1mm-10mm; wherein, a welding mark 13 is formed on the pole ear 12, and along the extension direction of the second monolithic pole ear layer 122, the distance between the free end 124 of the second monolithic pole ear layer 122 and the welding mark 13 is d, the free end 124 of the first monolithic pole ear layer 121 is located on the side of the welding mark 13 away from the battery body 11, and the free end 124 of the first monolithic pole ear layer 121 is spaced from the welding mark 13, and along the extension direction of the first monolithic pole ear layer 121, the distance between the free end 124 of the first monolithic pole ear layer 121 and the welding mark 13 is e, d / e≤40.

[0023] A battery in one embodiment of the utility model includes a battery cell 10, which includes a battery cell body 11 and a tab 12 extending from the battery cell body 11. The tab 12 is formed by stacking a plurality of single-piece tab layers, thereby ensuring that the battery cell 10 has reliable electrical performance and that the tab 12 itself has a sufficient current capacity. The plurality of monolithic tab layers include a first monolithic tab layer 121 and a second monolithic tab layer 122, a vertical distance between a connection end 123 and a free end 124 of the first monolithic tab layer 121 is not greater than a vertical distance between a connection end 123 and a free end 124 of other monolithic tab layers, and a vertical distance between a connection end 123 and a free end 124 of the second monolithic tab layer 122 is not less than a vertical distance between a connection end 123 and a free end 124 of other monolithic tab layers, that is, a vertical distance between the free end 124 of the first monolithic tab layer 121 and a free end 124 of the second monolithic tab layer 122 is the farthest distance between the plurality of free ends 124 of the plurality of monolithic tab layers, and the first monolithic tab layer 121 The vertical distance a between the free end 124 of the second monolithic tab layer 122 and the free end 124 of the second monolithic tab layer 122 is 1mm-10mm, thereby avoiding the distance between the two being too large. When the tab 12 is subsequently welded, the first monolithic tab layer 121 can be guaranteed to have a reliable welding area, thereby ensuring the welding quality of the tab 12, and further ensuring the safe use performance of the battery. The ratio of the distance d between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 to the distance e between the free end 124 of the first monolithic tab layer 121 and the weld mark 13 is less than or equal to 40, which can avoid the tab 12 being too long, thereby improving the space utilization rate during battery assembly, thereby effectively improving the use performance of the battery.

[0024] It should be noted that the tab 12 of the battery cell 10 extends from the battery cell body 11 , and the battery cell body 11 may be provided with two tabs 12 , which may be a positive tab and a negative tab, respectively.

[0025] Combination Figures 2 to 5 As shown, the tab 12 includes a plurality of monolithic tab layers, that is, the plurality of monolithic tab layers can be stacked relative to each other to form the tab 12. Each monolithic tab layer includes a connection end 123 and a free end 124, the connection end 123 is one end connected to the battery body 11, and the free end 124 is the other end away from the battery body 11, that is, the free end 124 is the outermost end of the monolithic tab layer.

[0026] After the multiple single-piece lug layers are stacked and converged, the multiple single-piece lug layers may not be cut. At this time, the end of the lug 12 is not flat. If the vertical distance between the two free ends 124 farthest apart of the multiple single-piece lug layers is too large, then when the lug 12 is subsequently welded, the probability that a single-piece lug layer is not completely covered by the weld mark will increase, which will reduce the connection strength between adjacent single-piece lug layers and may reduce the overall current carrying capacity of the lug 12.

[0027] Combination Figure 2 As shown, the direction in which the single-piece tab layer extends from the battery body 11 is represented as X, and the direction in which the single-piece tab layer extends from the battery body 11 is the direction in which the single-piece tab layer extends from the battery body 11 after the single-piece tab layer is straightened. The multiple single-piece tab layers include a first single-piece tab layer 121 and a second single-piece tab layer 122. The vertical distance between the connection end 123 and the free end 124 of the first single-piece tab layer 121 is not greater than the vertical distance between the connection end 123 and the free end 124 of the other single-piece tab layers. The second single-piece tab layer 122 The vertical distance between the connecting end 123 and the free end 124 is not less than the vertical distance between the connecting end 123 and the free end 124 of other monolithic tab layers, and the vertical distance a between the free end 124 of the first monolithic tab layer 121 and the free end 124 of the second monolithic tab layer 122 is 1mm-10mm, that is, the vertical distance between the two farthest free ends 124 of the multiple monolithic tab layers will not be too large, thereby effectively ensuring the welding contact area between each monolithic tab layer, thereby effectively controlling the welding effect of the tab 12.

[0028] The direction in which the single-piece tab layer extends from the battery body 11 is represented by X, and the vertical distance between the connecting end 123 and the free end 124 of the single-piece tab layer is the shortest distance between the free end 124 of the single-piece tab layer and the battery body 11.

[0029] Combination Figure 2 As shown, along the direction X in which the monolithic tab layer extends from the battery body 11, the vertical distance between the free end 124 of the first monolithic tab layer 121 and the free end 124 of the second monolithic tab layer 122 can be represented as a. The vertical distance a between the free end 124 of the first monolithic tab layer 121 and the free end 124 of the second monolithic tab layer 122 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm, etc.

[0030] When measuring the vertical distance a between the free end 124 of the first monolithic tab layer 121 and the free end 124 of the second monolithic tab layer 122, it is necessary to ensure that the portion of the first monolithic tab layer 121 close to the free end 124 is in a straight state, and correspondingly, the portion of the second monolithic tab layer 122 close to the free end 124 is in a straight state, so as to avoid natural bending of the ends of the first monolithic tab layer 121 and the second monolithic tab layer 122. At this time, the vertical distance a between the free end 124 of the first monolithic tab layer 121 and the free end 124 of the second monolithic tab layer 122 in the direction X along which the monolithic tab layers extend from the battery body 11 can be easily measured. Taking into account that the monolithic tab layer is relatively thin, the free end 124 of the first monolithic tab layer 121 and the free end 124 of the second monolithic tab layer 122 can basically be considered as a line, but the vertical distance a between the free end 124 of the first monolithic tab layer 121 and the free end 124 of the second monolithic tab layer 122 can be considered as the vertical distance between the first plane and the second plane where the free end 124 of the first monolithic tab layer 121 and the free end 124 of the second monolithic tab layer 122 are located, and the first plane and the second plane are perpendicular to the direction X in which the monolithic tab layer extends from the battery cell body 11.

[0031] like Figure 3 and Figure 4 As shown, a welding mark 13 is formed on the tab 12, so as to ensure reliable contact between the single tab layers, thereby ensuring the structural strength and current carrying capacity of the tab 12 itself.

[0032] It should be noted that the tab 12 is composed of a plurality of single tab layers, and the single tab layer may be a metal foil, for example, the single tab layer may be a copper sheet, or the single tab layer may be an aluminum sheet.

[0033] A weld mark 13 is formed on the pole lug 12, and the weld mark 13 can be formed by ultrasonic welding. For example, a plurality of single-piece pole lug layers are ultrasonically welded to form a pre-weld mark, and then laser welding can be used to form a laser weld mark on the pre-weld mark. The laser weld mark can be formed by welding the pole lug 12 and the pole column assembly 40, or the laser weld mark can be formed by welding the pole lug 12 and the adapter.

[0034] Alternatively, a welding mark 13 is formed on the pole tab 12 , and the welding mark 13 may be formed by ultrasonic welding. For example, a plurality of single-piece pole tab layers and the pole column assembly 40 may be directly welded by ultrasonic welding.

[0035] Alternatively, a welding mark 13 is formed on the pole tab 12 , and the welding mark 13 may be formed by laser welding. For example, a plurality of single-piece pole tab layers and the pole column assembly 40 may be directly laser welded.

[0036] Alternatively, a welding mark 13 is formed on the pole tab 12, and the welding mark 13 can be formed by resistance welding. For example, a plurality of single-piece pole tab layers and the pole column assembly 40 can be directly welded by resistance welding.

[0037] The ratio of the distance d between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 to the distance e between the free end 124 of the first monolithic tab layer 121 and the weld mark 13 is too large. When assembling, the second monolithic tab layer 122 occupies too much space in the battery casing, which affects the assembly and is not conducive to improving the space utilization rate of the battery casing.

[0038] The ratio of the distance d between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 to the distance e between the free end 124 of the first monolithic tab layer 121 and the weld mark 13 can be 40, 39, 38, 37, 36, 35, 34, 30, 25, 20, 15, 10 or 5, etc.

[0039] In one embodiment, along the extension direction of the second monolithic tab layer 122, the distance d between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 is 1.5 mm-20 mm, thereby ensuring to the greatest extent that each monolithic tab layer can have a relatively complete weld mark 13, ensuring the conductive performance of the tab 12, thereby improving the safe use performance of the battery.

[0040] Combination Figure 3 As shown, the distance between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 can be expressed as d. If the distance d between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 is too large, the weld mark 13 will be too close to the battery body 11, which may damage the battery body 11 and may be unfavorable for welding. If the distance d between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 is too small, a complete weld mark 13 may not be formed on part of the monolithic tab layer.

[0041] The distance d between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 can be considered as the distance between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 thereon after the second monolithic tab layer 122 is straightened.

[0042] The distance d between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 can be 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm or 20mm, etc.

[0043] In one embodiment, the free end 124 of the first monolithic tab layer 121 is located on the side of the weld mark 13 away from the battery body 11, and the free end 124 of the first monolithic tab layer 121 is spaced apart from the weld mark 13. Along the extension direction of the first monolithic tab layer 121, the distance e between the free end 124 of the first monolithic tab layer 121 and the weld mark 13 is 0.5mm-10mm, thereby ensuring that a complete weld mark 13 can be formed on the first monolithic tab layer 121, thereby ensuring the conductive performance of the tab 12 and controlling the current carrying capacity of the tab 12.

[0044] Combination Figure 3 As shown, the distance between the free end 124 of the first monolithic tab layer 121 and the weld mark 13 can be expressed as e. If the distance e between the free end 124 of the first monolithic tab layer 121 and the weld mark 13 is too large, the weld mark 13 will be too close to the battery body 11, which may damage the battery body 11 and may be unfavorable for welding. If the distance e between the free end 124 of the first monolithic tab layer 121 and the weld mark 13 is too small, the probability of damage to the free end 124 will increase, which may affect the welding quality of the tab 12.

[0045] The distance e between the free end 124 of the first single-piece tab layer 121 and the weld mark 13 can be considered as the distance between the free end 124 of the first single-piece tab layer 121 and the weld mark 13 thereon after the first single-piece tab layer 121 is straightened.

[0046] The distance e between the free end 124 of the first monolithic tab layer 121 and the weld mark 13 can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm, etc.

[0047] It should be noted that the pole tab 12 can be directly connected to the pole assembly 40 by welding, or the pole tab 12 can be connected to the pole assembly 40 by welding via an adapter.

[0048] In one embodiment, Figure 4As shown, the plurality of monolithic tab layers include a third monolithic tab layer 125 and a fourth monolithic tab layer 126, the third monolithic tab layer 125 and the fourth monolithic tab layer 126 are located at the outermost sides of the tab 12, along the extension direction of the third monolithic tab layer 125, the minimum distance between the connection end 123 of the third monolithic tab layer 125 and the weld mark 13 is b, along the extension direction of the fourth monolithic tab layer 126, the minimum distance between the connection end 123 of the fourth monolithic tab layer 126 and the weld mark 13 is c, b / c is 0.3- 10, and thus the pole ear 12 can have a certain deformation when it is gathered, thereby controlling the length of the pole ear 12, reducing the risk of accidental short circuit between the pole ear 12 and other structures, and thus improving the safe use performance of the battery. At the same time, the minimum distance b between the connection end 123 of the third single-piece pole ear layer 125 and the weld mark 13 and the minimum distance c between the connection end 123 of the fourth single-piece pole ear layer 126 and the weld mark 13 can form a bend at a suitable ratio. If one side is too short, no bend can be formed, and if one side is too long, wrinkles on the long side will be caused.

[0049] Combination Figure 4 As shown, along the extension direction of the third monolithic tab layer 125, the minimum distance between the connection end 123 of the third monolithic tab layer 125 and the weld mark 13 can be expressed as b, and along the extension direction of the fourth monolithic tab layer 126, the minimum distance between the connection end 123 of the fourth monolithic tab layer 126 and the weld mark 13 can be expressed as c.

[0050] The ratio of the minimum distance b between the connection end 123 and the weld mark 13 of the third monolithic tab layer 125 to the minimum distance c between the connection end 123 and the weld mark 13 of the fourth monolithic tab layer 126 can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10, etc.

[0051] When measuring the minimum distance b between the connection end 123 of the third monolithic tab layer 125 and the weld mark 13, the third monolithic tab layer 125 can be straightened to obtain the minimum distance b between the connection end 123 of the third monolithic tab layer 125 and the weld mark 13 thereon; correspondingly, when measuring the minimum distance c between the connection end 123 of the fourth monolithic tab layer 126 and the weld mark 13, the fourth monolithic tab layer 126 can be straightened to obtain the minimum distance c between the connection end 123 of the fourth monolithic tab layer 126 and the weld mark 13 thereon.

[0052] In one embodiment, Figure 4As shown, the fourth monolithic pole lug layer 126 includes a bending section 1261, and the bending section 1261 is located between the connecting end 123 and the weld mark 13 of the fourth monolithic pole lug layer 126; wherein, a recess 14 is formed on the side of the bending section 1261 away from the third monolithic pole lug layer 125, that is, the fourth monolithic pole lug layer 126 protrudes toward the side close to the third monolithic pole lug layer 125, thereby forming the bending section 1261 and the recess 14, that is, when the pole lug 12 is gathered and shaped, a recess 14 can be formed on the pole lug 12, which can not only facilitate the gathering of the pole lug 12, but also reduce the length of the pole lug 12, thereby avoiding the appearance of metal slag when the pole lug 12 is cut.

[0053] In one embodiment, the pole lug 12 is a positive pole lug, and the angle between the two opposite side walls of the recess 14 is 45°-90°, so that the spatial size of the recess 14 can be controlled, thereby maximally controlling the length of the pole lug 12 and avoiding cutting of the pole lug 12, thereby improving the molding efficiency of the battery.

[0054] The lug 12 is a positive electrode lug, and the angle between the two opposite side walls of the recess 14 can be 45°, 46°, 47°, 48°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85° or 90°, etc.

[0055] In one embodiment, the pole lug 12 is a negative pole lug, and the angle between the two opposite side walls of the recess 14 is 5°-40°, so that the length of the pole lug 12 can be controlled to the greatest extent by controlling the spatial size of the recess 14, thereby avoiding cutting of the pole lug 12, thereby improving the molding efficiency of the battery.

[0056] The tab 12 is a negative electrode tab, and the angle between the two opposite side walls of the recess 14 can be 5°, 6°, 7°, 8°, 10°, 15°, 20°, 25°, 30°, 35° or 40°, etc.

[0057] It should be noted that the angle between the two opposite walls of the depression 14 of the positive pole tab and the angle between the two opposite walls of the depression 14 of the negative pole tab can be the same inside the tooling. When the tooling is removed, the tab is free and unrestrained, that is, the tab 12 will rebound to form a depression 14. The angle between the two opposite walls of the depression 14 of the negative pole tab is small, and the angle between the two opposite walls of the depression 14 of the positive pole tab is large. The single-piece tab layer of the negative pole tab is thin and soft and easy to fold down. The negative pole tab has a small rebound force and a small angle. The single-piece tab layer of the positive pole tab is thick and hard and not easy to fold down. The positive pole tab has a large rebound force and a large angle.

[0058] The angle between the two opposite side walls of the recess 14 of the tab 12 can be measured by:

[0059] 1. The battery is disassembled, and the tab 12 is peeled off from the cover. When the tab 12 is free, the opposite side walls of the recess 14 of the positive tab are retracted at an angle of 45°-90°, and the opposite side walls of the recess 14 of the negative tab are retracted at an angle of 5°-40°.

[0060] 2. Disassemble the battery, separate the shell cover, remove the low-viscosity film or mylar film that gathers the tabs and the cover plate, remove the support parts such as the retainer at the root of the tab 12, and the cover plate is free. No external force is applied to the cover plate. When the tab 12 is free, the opposite side walls of the recess 14 of the positive tab are gathered at an angle of 45°-90°, and the opposite side walls of the recess 14 of the negative tab are gathered at an angle of 5°-40°.

[0061] It should be noted that, along the extension direction of the third monolithic tab layer 125, the minimum distance between the connection end 123 of the third monolithic tab layer 125 and the weld mark 13 is b, and along the extension direction of the fourth monolithic tab layer 126, the minimum distance between the connection end 123 of the fourth monolithic tab layer 126 and the weld mark 13 is c, and b / c is 0.3-10, thereby allowing the free end 124 of the third monolithic tab layer 125 and the free end 124 of the fourth monolithic tab layer 126 to be misaligned, and the formation of the recess 14, that is, the tab 12 can be V-shaped, and after the tab 12 is completely folded, ultrasonic welding can be performed, and the tab 12 can be in an arc shape. Not cutting the tab 12 to cooperate with the V-shaped bending can also reduce the length of the tab 12 and improve the yield of the rolling and lamination processes.

[0062] In one embodiment, the weld mark 13 is an ultrasonic weld mark, which can not only ensure the welding quality of the tab 12 , but also effectively reduce the probability of damage to the tab 12 , thereby ensuring the current carrying capacity of the tab 12 .

[0063] The weld mark 13 is an ultrasonic weld mark. For example, the weld mark 13 is formed by ultrasonically pre-welding a plurality of single-piece tab layers. Subsequently, laser welding can be used to form a connection between the tab 12 and the pole assembly. The laser weld mark can be formed on the weld mark 13 .

[0064] Alternatively, the weld mark 13 is an ultrasonic weld mark, for example, a plurality of single-piece tab layers are directly welded to the pole assembly by ultrasonic waves, thereby forming the weld mark 13 .

[0065] In one embodiment, the weld mark 13 is a laser weld mark, so as to ensure the connection stability between the pole tab 12 and the pole assembly and improve the connection efficiency between the pole tab 12 and the pole assembly.

[0066] The weld mark 13 is a laser weld mark. For example, the connection between the pole ear 12 and the pole assembly is achieved by laser welding, thereby forming the weld mark 13 .

[0067] In one embodiment, Figure 4 and Figure 5 As shown, the pole lug 12 is formed with a recess 14, the pole lug 12 is a positive pole lug, and the angle between the two opposite side walls of the recess 14 is 45°-85°; or, the pole lug 12 is a negative pole lug, and the angle between the two opposite side walls of the recess 14 is 5°-45°. The formation of the recess 14 can not only facilitate the convergence of the pole lug 12 and reduce the overall length of the pole lug 12, but also effectively ensure the overall current capacity of the pole lug 12, and facilitate the subsequent welding of the pole lug 12.

[0068] If the angle between the two opposite side walls of the depression 14 is too large, it is not only not conducive to the bending and convergence of the pole ear 12, but also it is impossible to control the length of the pole ear 12; if the angle between the two opposite side walls of the depression 14 is too small, the degree of bending of the pole ear 12 is too large, which may cause stress concentration and the risk of breaking the pole ear 12. By making the angle between the two opposite side walls of the depression 14 of the positive pole ear not less than the angle between the two opposite side walls of the depression 14 of the negative pole ear, the length relationship between the positive pole ear and the negative pole ear can be easily adjusted, thereby ensuring the operating capacity of the battery.

[0069] It should be noted that the two opposite side walls of the recess 14 are not necessarily standard planes. It is not ruled out that the two opposite side walls of the recess 14 may have a certain curvature, but it does not affect the measurement of the angle formed by the two opposite side walls of the recess 14 as a whole.

[0070] In one embodiment, Figure 5 As shown, the battery also includes an insulating layer 20, and at least a portion of the insulating layer 20 is disposed on the pole lug 12, so that the insulating layer 20 can form an insulating protection for the pole lug 12, reduce the risk of tearing the pole lug 12, and reduce the risk of metal chips on the pole lug 12 falling, thereby improving the safe use performance of the battery.

[0071] The thickness of the insulating layer 20 is 0.01 mm-0.1 mm. On the basis of ensuring that the insulating layer 20 has a certain structural strength, it can also avoid that the thickness of the insulating layer 20 is too large, which occupies a large space and is not conducive to improving the overall energy density of the battery.

[0072] The thickness of the insulating layer 20 may be 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm or 0.1 mm, etc.

[0073] In one embodiment, the insulating layer 20 is bonded to the tab 12 , thereby ensuring that the insulating layer 20 is reliably fixed to the tab 12 and reducing the risk of the insulating layer 20 falling off.

[0074] The insulating layer 20 is a tape, which not only has a simple structure but also facilitates the arrangement of the insulating layer 20 , thereby improving the overall manufacturing efficiency of the battery.

[0075] The insulating layer 20 is disposed on the outermost side of the tab 12 . For example, the insulating layer 20 may be disposed on the third monolithic tab layer 125 , or the insulating layer 20 may be disposed on the fourth monolithic tab layer 126 , or both the third monolithic tab layer 125 and the fourth monolithic tab layer 126 may be provided with the insulating layer 20 .

[0076] The insulating layer 20 may extend from the battery cell body 11 to the pole tab 12 , or the insulating layer 20 may be disposed only on the pole tab 12 .

[0077] In one embodiment, the battery cell 10 is a square battery cell, and the thickness of the battery cell 10 is 5mm-50mm, that is, the thickness of the battery cell 10 can be relatively large, and the length of the single-piece tab layer will be relatively long. Therefore, it is more necessary to control the vertical distance a between the free end 124 of the first single-piece tab layer 121 and the free end 124 of the second single-piece tab layer 122, so as to ensure the welding quality of the tab 12, and then ensure the safe use performance of the battery.

[0078] The thickness of the battery cell 10 can be 5mm, 6mm, 7mm, 8mm, 10mm, 12mm, 15mm, 18mm, 20mm, 22mm, 25mm, 28mm, 30mm, 32mm, 35mm, 38mm, 40mm, 42mm, 45mm, 48mm or 50mm, etc.

[0079] It should be noted that, in some embodiments, it is not excluded that the battery cell 10 may be a cylindrical battery cell.

[0080] In one embodiment, the battery cell 10 is a stacked battery cell. After the battery cell 10 is formed by stacking, the number of single-piece tab layers of the tab 12 of the battery cell 10 will be relatively large. Therefore, the vertical distance a between the free end 124 of the first single-piece tab layer 121 and the free end 124 of the second single-piece tab layer 122 can be controlled to facilitate the subsequent welding of the tab 12.

[0081] It should be noted that, in some embodiments, it is not excluded that the battery cell 10 may be a wound battery cell.

[0082] In one embodiment, Figure 1As shown, the battery also includes a battery shell 30, the battery cell 10 is arranged in the battery shell 30, and a pole assembly 40 can be arranged on the battery shell 30. There can be two pole assemblies 40, and the two pole assemblies 40 can be a positive pole assembly and a negative pole assembly respectively. Two pole ears 12 can be arranged on the battery body 11, and the two pole ears 12 can be a positive pole ear and a negative pole ear respectively. The positive pole ear and the negative pole ear can be electrically connected to the positive pole assembly and the negative pole assembly respectively.

[0083] It should be noted that the battery includes a cell and an electrolyte, which is the smallest unit capable of performing electrochemical reactions such as charge / discharge. A cell refers to a unit formed by winding or laminating a stacked portion, the stacked portion including a first pole sheet, a separator, and a second pole sheet. When the first pole sheet is a positive pole sheet, the second pole sheet is a negative pole sheet. The polarities of the first pole sheet and the second pole sheet can be interchanged. The first pole sheet and the second pole sheet are coated with an active material.

[0084] In one embodiment, the battery may be a quadrangular prism battery. A quadrangular prism battery mainly refers to a battery having a prism shape, but it is not strictly limited whether each side of the prism must be a straight line in the strict sense, and the corners between the sides are not necessarily right angles, and can be arc transitions.

[0085] The battery can be a laminated battery, which is not only convenient to group, but also can be processed to obtain a longer battery. Specifically, the battery cell is a laminated battery cell, which has a first pole piece stacked on top of each other, a second pole piece with electrical properties opposite to the first pole piece, and a diaphragm sheet arranged between the first pole piece and the second pole piece, so that multiple pairs of first pole pieces and second pole pieces are stacked to form a laminated battery cell.

[0086] Alternatively, the battery may be a wound battery, that is, a first pole sheet, a second pole sheet with electrical properties opposite to the first pole sheet, and a diaphragm sheet arranged between the first pole sheet and the second pole sheet are wound to obtain a wound battery cell.

[0087] In one embodiment, the battery may be a cylindrical battery, or the battery may be a hexagonal prism battery. The battery may be a wound battery, that is, a first pole piece, a second pole piece with electrical properties opposite to the first pole piece, and a diaphragm sheet disposed between the first pole piece and the second pole piece are wound to obtain a wound battery cell.

[0088] An embodiment of the utility model further provides a battery pack, which includes batteries.

[0089] A battery of a battery pack of an embodiment of the utility model includes a battery cell 10, and the battery cell 10 includes a battery cell body 11 and a pole ear 12 extending from the battery cell body 11, and the pole ear 12 is formed by stacking a plurality of single-piece pole ear layers, thereby ensuring that the battery cell 10 has reliable electrical performance and the current carrying capacity of the pole ear 12 itself can also be guaranteed. The multiple monolithic tab layers include a first monolithic tab layer 121 and a second monolithic tab layer 122, the vertical distance between the connecting end 123 and the free end 124 of the first monolithic tab layer 121 is not greater than the vertical distance between the connecting end 123 and the free end 124 of the other monolithic tab layers, and the vertical distance between the connecting end 123 and the free end 124 of the second monolithic tab layer 122 is not less than the vertical distance between the connecting end 123 and the free end 124 of the other monolithic tab layers, that is, the vertical distance between the free end 124 of the first monolithic tab layer 121 and the free end 124 of the second monolithic tab layer 122 is the farthest between the multiple free ends 124 of the multiple monolithic tab layers, and the vertical distance between the connecting end 123 and the free end 124 of the first monolithic tab layer 121 is the longest between the multiple free ends 124 of the multiple monolithic tab layers, and the vertical distance between the connecting end 123 and the free end 124 of the second monolithic tab layer 122 is the longest ... monolithic tab layers, and the vertical distance between the connecting end 123 and the free end 124 of the second monolithic tab layer 122 is the longest between the multiple monolithic tab layers, and the vertical distance between the connecting end 123 and the free end 124 of the first monolithic tab layer 121 is the longest between The vertical distance a between the free end 124 and the free end 124 of the second monolithic tab layer 122 is 1mm-10mm, thereby avoiding the distance between the two being too large. When the tab 12 is subsequently welded, the first monolithic tab layer 121 can be guaranteed to have a reliable welding area, thereby ensuring the welding quality of the tab 12, and further ensuring the safe use performance of the battery pack. The ratio of the distance d between the free end 124 of the second monolithic tab layer 122 and the weld mark 13 to the distance e between the free end 124 of the first monolithic tab layer 121 and the weld mark 13 is less than or equal to 40, which can avoid the tab 12 being too long, thereby improving the space utilization rate during battery assembly, thereby effectively improving the battery performance.

[0090] In one embodiment, the battery pack is a battery module or a battery pack.

[0091] The battery module includes a plurality of batteries, and the battery module may further include an end plate and a side plate, and the end plate and the side plate are used to fix the plurality of batteries.

[0092] It should be noted that multiple batteries can be arranged in a battery box after forming a battery module, and multiple batteries can be fixed by end plates and side plates. Multiple batteries can be directly arranged in the battery box, that is, there is no need to group multiple batteries, in which case the end plates and side plates can be removed.

[0093] Those skilled in the art will readily come up with other embodiments of the present disclosure after considering the specification and practicing the utility model disclosed herein. The present disclosure is intended to cover any variation, use or adaptation of the present utility model, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and example embodiments are to be regarded as exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

[0094] It should be understood that the present disclosure is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from its scope. The scope of protection of the present disclosure is limited only by the appended claims.

Claims

1. A battery, characterized in that: The invention comprises a battery cell (10), wherein the battery cell (10) comprises: A battery cell body (11); A pole lug (12), the pole lug (12) extending from the battery cell body (11), the pole lug (12) comprising a plurality of single-piece pole lug layers, each of the single-piece pole lug layers comprising a connection end (123) connected to the battery cell body (11) and a free end (124) away from the battery cell body (11), the plurality of single-piece pole lug layers comprising a first single-piece pole lug layer (121) and a second single-piece pole lug layer (122); In the direction in which the monolithic tab layer extends from the battery body (11), the vertical distance between the connecting end (123) and the free end (124) of the first monolithic tab layer (121) is not greater than the vertical distance between the connecting end (123) and the free end (124) of other monolithic tab layers, the vertical distance between the connecting end (123) and the free end (124) of the second monolithic tab layer (122) is not less than the vertical distance between the connecting end (123) and the free end (124) of other monolithic tab layers, and the vertical distance a between the free end (124) of the first monolithic tab layer (121) and the free end (124) of the second monolithic tab layer (122) is 1 mm-10 mm; A welding mark (13) is formed on the pole lug (12); along the extension direction of the second single-piece pole lug layer (122), the distance between the free end (124) of the second single-piece pole lug layer (122) and the welding mark (13) is d; the free end (124) of the first single-piece pole lug layer (121) is located on a side of the welding mark (13) away from the battery cell body (11); the free end (124) of the first single-piece pole lug layer (121) is spaced from the welding mark (13); along the extension direction of the first single-piece pole lug layer (121), the distance between the free end (124) of the first single-piece pole lug layer (121) and the welding mark (13) is e, and d / e≤40.

2. The battery according to claim 1, characterized in that d is 1.5 mm-20 mm; and / or, e is 0.5 mm-10 mm.

3. The battery according to claim 1, characterized in that The plurality of monolithic tab layers include a third monolithic tab layer (125) and a fourth monolithic tab layer (126), wherein the third monolithic tab layer (125) and the fourth monolithic tab layer (126) are located at the outermost sides of the tab (12), and along the extension direction of the third monolithic tab layer (125), the minimum distance between the connection end (123) of the third monolithic tab layer (125) and the weld mark (13) is b, and along the extension direction of the fourth monolithic tab layer (126), the minimum distance between the connection end (123) of the fourth monolithic tab layer (126) and the weld mark (13) is c, and b / c is 0.3-10.

4. The battery according to claim 3, characterized in that The fourth single-piece tab layer (126) comprises a bending section (1261), and the bending section (1261) is located between the connection end (123) of the fourth single-piece tab layer (126) and the weld mark (13); Wherein, a recess (14) is formed on a side of the bending section (1261) facing away from the third single-piece tab layer (125).

5. The battery according to claim 4, characterized in that The pole lug (12) is a positive pole lug, and the angle between the two opposite side walls of the recess (14) is 45°-85°; or, the pole lug (12) is a negative pole lug, and the angle between the two opposite side walls of the recess (14) is 5°-45°.

6. The battery according to any one of claims 1 to 5, characterized in that The welding mark (13) is an ultrasonic welding mark; or, the welding mark (13) is a laser welding mark.

7. The battery according to any one of claims 1 to 4, characterized in that The pole ear (12) is formed with a recess (14); Wherein, the pole lug (12) is a positive pole lug, and the angle between the two opposite side walls of the recess (14) is 45°-90°; or, the pole lug (12) is a negative pole lug, and the angle between the two opposite side walls of the recess (14) is 5°-40°.

8. The battery according to any one of claims 1 to 5, characterized in that The battery further comprises an insulating layer (20), at least a portion of the insulating layer (20) being disposed on the electrode tab (12); Wherein, the thickness of the insulating layer (20) is 0.01 mm-0.1 mm.

9. The battery according to claim 8, characterized in that The insulating layer (20) is bonded to the tab (12); Wherein, the insulating layer (20) is an adhesive tape.

10. The battery according to any one of claims 1 to 5, characterized in that The battery core (10) is a square battery core, and the thickness of the battery core (10) is 5 mm-50 mm.

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