Battery cell welding structure and battery
By setting the welding points formed by welding the full pole ear and the current collector in the battery along the winding direction, the problem of uneven current when the pole ear conducts current to the pole ear is solved, and uniform reception of the pole ear current and reduction of energy loss are achieved.
Patent Information
- Application Number
- CN202421355114.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-13
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-06-13
AI Technical Summary
In a cylindrical battery, welding of the electrode ear and the electrode sheet causes the current to flow into the electrode sheet unevenly, resulting in excessive current receiving in some areas and excessive current receiving in some areas.
By setting multiple welding points formed by welding the full pole ear and the current collector along the winding direction, the welding points are evenly distributed on the full pole ear, thereby uniformly introducing current to the pole sheet.
The uniformity of the pole sheet receiving current is achieved, and the additional path conduction of the current in the winding body is reduced for uniform distribution, thereby reducing energy loss.
Smart Images
Figure CN222927732U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of battery technology, and in particular to a battery core welding structure and a battery. Background Art
[0002] In cylindrical batteries, the tabs are welded to the pole pieces and the current is conducted to the pole pieces through the welding points. In related technologies, the welding of the tabs to the pole pieces usually adopts the method of full-tab laser welding, which will form multiple welding points, and the pattern composed of multiple welding points is in the shape of "V" or "M". When the tabs conduct current to the pole pieces through the welding points, the distribution of "V" and "M" shaped welding points will cause some parts of the pole pieces to receive more current, while other parts receive less current, and the current cannot flow into the pole pieces evenly. Utility Model Content
[0003] The embodiments of the present application provide a battery cell welding structure and a battery, which are used to improve the technical problem of uneven current received by the pole piece when the pole tab conducts current to the pole piece.
[0004] In a first aspect, an embodiment of the present application provides a battery core welding structure, including:
[0005] winding body;
[0006] A full pole ear is formed at the end of the winding body;
[0007] A current collector, welded to a side of the full pole tab away from the winding body to form a plurality of welding points;
[0008] Wherein, the plurality of welding points are arranged at equal arc distances along the winding direction of the winding body.
[0009] In some embodiments of the present application, the plurality of welding points form a plurality of welding point groups, and the welding points in each welding point group are arranged in an arc shape along the radial direction of the winding body.
[0010] In some embodiments of the present application, the plurality of welding point groups are arranged in a spiral shape along the winding direction of the winding body and form at least one spiral track.
[0011] In some embodiments of the present application, the winding body includes an inner diameter, an outer diameter and the number of winding turns. When the difference between the outer diameter and the inner diameter is constant, the number and quantity of turns of the spiral trajectory are positively correlated with the number of winding turns; when the number of winding turns is constant, the number and quantity of turns of the spiral trajectory are negatively correlated with the difference between the outer diameter and the inner diameter.
[0012] In some embodiments of the present application, the inner diameter ranges from 4 to 7 mm, and / or the outer diameter ranges from 10 to 70 mm, and / or the number of winding turns ranges from 20 to 100 turns, and / or along the winding direction of the winding body, the arc distance between two adjacent solder joints ranges from 2 to 20 mm.
[0013] In some embodiments of the present application, the inner diameter is 5 to 7 mm, the outer diameter is 55 to 65 mm, the number of winding turns is 80 to 100 turns, and along the winding direction of the winding body, the arc distance between two adjacent solder joints ranges from 3 to 5 mm, the number of spiral trajectories is one, and the number of turns of the spiral trajectory is one turn.
[0014] In some embodiments of the present application, the inner diameter is 5 to 7 mm, the outer diameter is 35 to 45 mm, the number of winding turns is 80 to 100 turns, and along the winding direction of the winding body, the arc distance between two adjacent solder joints ranges from 3 to 5 mm, the number of spiral trajectories is two, and the number of turns of each spiral trajectory is three turns.
[0015] In some embodiments of the present application, the inner diameter is 5 to 7 mm, the outer diameter is 17 to 27 mm, the number of winding turns is 80 to 100 turns, and along the winding direction of the winding body, the arc distance between two adjacent solder joints ranges from 3 to 5 mm, the number of spiral trajectories is one, and the number of turns of the spiral trajectory is two turns.
[0016] In some embodiments of the present application, the solder joints are dot-shaped, and the diameter of the solder joints ranges from 0.5 to 3 mm.
[0017] In a second aspect, an embodiment of the present application provides a battery, including the battery cell welding structure as described in the first aspect.
[0018] Advantages of the embodiments of the present application:
[0019] In the embodiments of the present application, mainly by arranging multiple solder joints formed by welding the full tab and the current collector at equal arc distances in the winding direction, the solder joints can be evenly distributed on the full tab along the winding direction. When the current collector conducts current into the winding body through the full tab, the current can be evenly introduced into the electrode sheet through the solder joints that tend to be evenly distributed, improving the uniformity of the electrode sheet receiving current. Specifically, first, the full tab is electrically connected to the winding body, enabling the winding body to be electrically connected to external components through the full tab to achieve current conduction. Then, by using the welding method, the full tab is connected to the current collector. At the welding point, multiple solder joints are formed on the full tab. The multiple solder joints are arranged at equal arc distances along the winding direction of the winding body, so that the multiple solder joints are evenly distributed in the winding direction. When the current introduced by the full tab into the current collector passes through the multiple solder joints, because each solder joint is in a state of tending to be evenly distributed, the current introduced into the winding body from the solder joints is more uniform than the current introduced into the winding body irregularly. Since the positions where the current is introduced are relatively uniform, after the current flows into the winding body, it can effectively reduce the additional path conduction of the current in the winding body for uniform distribution, and reduce the energy loss caused by the uneven inflow of the current into the winding body. Description of the Drawings
[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0021] Figure 1 It is a schematic diagram of the position distribution of the solder joints after the electrode sheet is wound in the first example provided by the embodiment of the present application;
[0022] Figure 2 It is a schematic diagram of the position distribution of the solder joints after the electrode sheet is wound in the second example provided by the embodiment of the present application;
[0023] Figure 3 It is a schematic diagram of the position distribution of the solder joints after the electrode sheet is wound in the third example provided by the embodiment of the present application;
[0024] Figure 4 It is a schematic diagram of the unfolded structure after hiding the current collector in the cell welding structure provided by the embodiment of the present application.
[0025] Description of the Reference Numerals:
[0026] 100, winding body; 110, electrode sheet; 200, full tab; 210, solder joint group; 211, solder joint; X, length direction; Y, width direction; Q, winding direction. Detailed Embodiments
[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the directional words such as "upper" and "lower" used generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.
[0028] See also Figures 1 to 4 , an embodiment of the present application provides a battery core welding structure, including:
[0029] A winding body 100;
[0030] A full tab 200 is formed at an end of the winding body 100 and is electrically connected to the winding body 100;
[0031] A current collector, welded to a side of the full tab 200 away from the winding body 100 to form a plurality of welding points 211;
[0032] The plurality of welding points 211 are arranged at equal arc distances along the winding direction Q of the winding body 100 .
[0033] It should be noted that the winding body 100 includes a pole piece 110 arranged in a wound state and a diaphragm attached to the pole piece 110, and the full pole tab 200 is electrically connected to the pole piece 110 and is located at one end of the winding body 100. The pole piece 110 is in a sheet shape before winding, and has a length direction X and a width direction Y. After the pole piece 110 is wound, the pole piece 110 has a winding direction Q generated by the winding, and at this time, the pole piece 110 is formed into a winding body 100. In the subsequent description of the pole piece 110, if it is not specifically stated that the pole piece 110 is in a sheet shape or before winding, it refers to the state of the pole piece 110 being a winding body 100 after winding. It should also be noted that the formation of the wound body 100 should also include a diaphragm, which is wound along with the winding of the pole piece 110. However, since the invention of this application is mainly related to the pole ear, the pole piece 110 and the welding point 211, and the diaphragm also belongs to the prior art in the battery, it will not be repeated here. The subsequent formation of the wound body 100 will be described as the winding formation of the pole piece 110.
[0034] The technical solution provided by this application mainly sets multiple solder joints 211 formed by welding the full tab 200 and the current collector at equal arc distances in the winding direction Q, so that the solder joints 211 can be evenly distributed on the full tab 200 along the winding direction Q. When the current collector conducts current into the winding body 100 through the full tab 200, the current can be evenly introduced into the electrode sheet 110 through the solder joints 211 that tend to be evenly distributed, improving the uniformity of the electrode sheet 110 receiving current. Specifically, first, the full tab 200 is electrically connected to the winding body 100, so that the winding body 100 can be electrically connected to external components through the full tab 200 to achieve current conduction. Then, by using the welding method, the full tab 200 is connected to the current collector. At the welding point, multiple solder joints 211 are formed on the full tab 200. The multiple solder joints 211 are set at equal arc distances along the winding direction Q of the winding body 100, so that the multiple solder joints 211 are evenly distributed in the winding direction Q. When the current introduced by the full tab 200 into the current collector passes through the multiple solder joints 211, because each solder joint 211 is in a state of tending to be evenly distributed, the current introduced from the solder joints 211 into the winding body 100 is more uniform than the current introduced into the winding body 100 irregularly. Since the positions where the current is introduced are relatively uniform, after the current flows into the winding body 100, it can effectively reduce the extra path conduction of the current inside the winding body 100 for uniform distribution, and reduce the energy loss caused by the uneven inflow of the current into the winding body 100.
[0035] In some embodiments, along the winding direction Q, the multiple solder joints 211 are set at equal arc distances. By setting all the solder joints 211 on the full tab 200 at equal arc distances along the winding direction Q, as the electrode sheet 110 is wound, each solder joint 211 located on the full tab 200 will also form a unique spiral trajectory along the winding direction Q. The number of the spiral trajectories, the number of spiral turns, etc. vary with the arc length between adjacent solder joints 211, the number of winding turns of the electrode sheet 110, and the inner diameter and outer diameter formed by winding. The multiple solder joints 211 have equal arc lengths and form a spiral trajectory, so that the multiple solder joints 211 can be evenly distributed on the path wound by the electrode sheet 110. Subsequently, when the electrode sheet 110 receives the current conducted from the full tab 200, the current can be introduced into the electrode sheet 110 through the evenly distributed solder joints 211, improving the uniformity of the electrode sheet 110 receiving current and reducing the loss of current inside the electrode sheet 110.
[0036] It should be noted that for the equal-arc-distance setting of multiple solder joints 211, etc., in this embodiment, mainly through simulation software, such as AutoCAD, according to the input parameters, the simulation of the solder joint trajectory is carried out. After obtaining the simulation result of the solder joint trajectory, the result is input to the actuator, and the actuator completes the welding according to the simulated solder joint trajectory. If the wound body 100 after welding and the full tab 200 connected to the wound body 100 are unfolded to restore the wound body 100 to the sheet-like electrode tab 110 and the full tab 200, the full tab 200 is located at one end of the electrode tab 110 in the width direction Y, and there are multiple traces of solder joints 211 arranged at equal intervals along the length direction X on the full tab 200.
[0037] In some embodiments, multiple solder joints 211 arranged at intervals in the radial direction form multiple solder joint groups 210, and the multiple solder joint groups 210 are arranged in a spiral shape along the winding direction Q of the wound body 100 and form at least one spiral trajectory. Here, the spiral trajectory does not refer to the spiral trajectory formed by the winding of the electrode tab 110, but the spiral trajectory formed by the multiple solder joint groups 210. Specifically, each solder joint group 210 is regarded as a point, and the spiral trajectory formed by connecting the multiple solder joint groups 210 along the winding direction Q. By making the multiple solder joint groups 210 form a spiral trajectory along the winding direction Q, when the full tab 200 conducts current to the electrode tab 110, there are solder joints 211 at each position of the electrode tab 110 along the winding direction Q to receive the current, so as to ensure that the current conducted by the full tab 200 to the electrode tab 110 is uniform.
[0038] Furthermore, the wound body 100 has a radial direction. The solder joints 211 within each solder joint group 210 are arranged at intervals in the radial direction and are arranged in an arc shape so that the solder joint group 210 is in an arc shape. As the number of turns of the winding of the electrode tab 110 increases, the outer diameter of the wound body 100 gradually increases, and along the winding direction Q, the arc distance between adjacent two solder joints 211 remains unchanged. It can be deduced that the number of solder joints 211 on the full tab 200 corresponding to the later turn of the winding of the electrode tab 110 is greater than the number of solder joints 211 on the full tab 200 corresponding to the previous turn, so that along the radial direction, the connection line of the multiple solder joints 211 is in an arc shape, that is, the solder joint group 210 is in an arc shape. Furthermore, the arrangement of the multiple solder joints 211 on the electrode tab 110 has a certain pattern, specifically distributed on each turn of the winding of the electrode tab 110, rather than being arranged randomly, which is beneficial to the electrode tab 110 to uniformly receive the current conducted by the full tab 200, reduce the path movement of the current in the electrode tab 110 to make the current inside the electrode tab 110 uniform, and reduce the loss of the current.
[0039] In some embodiments, the wound body 100 includes an inner diameter, an outer diameter, and the number of wound turns. When the difference between the outer diameter and the inner diameter is constant, both the number of turns and the quantity of the spiral trajectory are positively correlated with the number of wound turns; when the number of wound turns is constant, both the number of turns and the quantity of the spiral trajectory are inversely correlated with the difference between the outer diameter and the inner diameter. It should be noted that: for the inner diameter, it refers to the diameter of the circle formed along the winding path of the first turn when the electrode tab 110 is being wound. For the outer diameter, it refers to the diameter of the circle formed along the winding path of the last turn when the electrode tab 110 is wound to the last turn. That is to say, when the difference between the outer diameter and the inner diameter is larger, the number of turns of the spiral trajectory is smaller. This is because when the difference between the outer diameter and the inner diameter is larger, it means that the size formed by winding the current electrode tab 110 is larger, and there is a long enough spiral line length to accommodate more welding points 211, so that the arc length of the interval between the multiple welding points 211 does not need to be shortened, and even if the number of turns of the spiral trajectory formed by the multiple welding points 211 is less, it can still meet the setting of all the welding points 211. When the difference between the outer diameter and the inner diameter is smaller, the number of turns of the spiral trajectory is larger. This is because when the difference between the outer diameter and the inner diameter is smaller, it means that the size formed by winding the current electrode tab 110 is smaller, and the spiral length of the electrode tab 110 is shorter. When it is necessary to accommodate more welding points 211, it is necessary to increase the number of turns of the spiral trajectory so that the multiple welding points 211 can be evenly arranged on the electrode tab 110. The number of turns of the spiral trajectory is positively correlated with the number of wound turns. That is to say, when the number of turns of the electrode tab 110 wound is more, the number of turns of the spiral trajectory is also more. This is because the spiral trajectory is mainly formed by multiple welding point groups 210, and the multiple welding point groups 210 are formed by multiple welding points 211. The more the number of wound turns, the more the number of welding points 211, and the more the number of turns of the formed spiral trajectory. The quantity of the spiral trajectory here refers to the number of spiral trajectories. The spiral trajectory is formed by arranging multiple welding point groups 210 at intervals along the winding direction Q. The larger the difference between the outer diameter and the inner diameter, the fewer the quantity of the spiral trajectory, and the smaller the diameter difference, the more the quantity of the spiral trajectory. The more the number of wound turns of the electrode tab 110, the more the quantity of the spiral trajectory, and the fewer the number of wound turns, the fewer the quantity of the spiral trajectory.
[0040] In some embodiments, the inner diameter ranges from 4 to 7 mm, and / or the outer diameter ranges from 10 to 70 mm, and / or the number of wound turns ranges from 20 to 100 turns, and / or along the winding direction Q of the wound body 100, the arc distance between two adjacent welding points 211 ranges from 2 to 20 mm. For different values of the inner diameter, the outer diameter, and the number of wound turns, the quantity and structure of the formed spiral trajectory are also different. The following gives examples of different values:
[0041] In the first example, please refer to Figure 1, when the inner diameter is 5 to 7 mm, the outer diameter is 55 to 65 mm, the number of winding turns is 80 to 100 turns, and along the winding direction Q of the winding body 100, the arc distance between two adjacent solder joints 211 ranges from 3 to 5 mm, the number of the spiral tracks is one, and a plurality of solder joint groups 210 in the spiral track form one circle of the spiral track along the winding direction Q. Preferably, in this embodiment, the inner diameter is 5 mm, the outer diameter is 60 mm, the number of winding turns is 90 turns, and along the winding direction of the winding body, the arc distance between two adjacent solder joints is 4 mm. In this embodiment, a plurality of formed solder joints 211 can be evenly distributed at one end of the pole piece 110 along the spiral direction. When the pole piece 110 receives the current introduced by the full pole ear 200, the introduced current is evenly introduced to each position of the pole piece 110 through the solder joints 211, reducing the current flow path and reducing the power loss.
[0042] In the second example, please refer to Figure 2 , when the inner diameter is 5 to 7 mm, the outer diameter is 35 to 45 mm, the number of winding turns is 80 to 100 turns, and along the winding direction Q of the winding body 100, the arc distance between two adjacent solder joints 211 ranges from 3 to 5 mm, the number of the spiral tracks is two, and a plurality of solder joint groups 210 in each spiral track form three circles of the spiral track along the winding direction Q. Preferably, in this embodiment, the inner diameter is 5 mm, the outer diameter is 40 mm, the number of winding turns is 90 turns, and along the winding direction of the winding body, the arc distance between two adjacent solder joints is 4 mm. Compared with the first example, in this example, only the outer diameter is reduced, the outer diameter is reduced from 60 mm to 40 mm, the number of the spiral tracks changes from one to two, and the spiral tracks formed by the solder joint groups 210 in the spiral track along the winding direction Q increase to three circles. It can be seen that when the difference between the outer diameter and the inner diameter decreases, the number of the spiral tracks will increase, and the spiral tracks will also increase.
[0043] In the third example, please refer to Figure 3 , when the inner diameter is 5 to 7 mm, the outer diameter is 17 to 27 mm, the number of winding turns is 80 to 100 turns, and along the winding direction Q of the winding body 100, the arc distance between two adjacent solder joints 211 ranges from 3 to 5 mm, the number of the spiral tracks is one, and a plurality of solder joint groups 210 in the spiral track form two circles of the spiral track along the winding direction Q. Preferably, in this embodiment, the inner diameter is 5 mm, the outer diameter is 22 mm, the number of winding turns is 90 turns, and along the winding direction of the winding body, the arc distance between two adjacent solder joints is 4 mm. Compared with the first example, in this example, the outer diameter is reduced, the outer diameter is reduced from 60 mm to 22 mm, and the spiral tracks formed by the solder joint groups 210 in the spiral track along the winding direction Q increase to three circles.
[0044] It should be noted that the solder joints 211 described in any of the above embodiments are all formed by spot welding. By using the spot welding method, the distances of the solder joints 211 on the full tab 200 along the winding direction Q are uniform, which is beneficial to uniformly introducing current from the full tab 200 to the electrode sheet 110. Moreover, by forming the solder joints 211 by spot welding, the size of the solder joints 211 can be changed according to the actual situation, so as to meet the requirements for the pulling force between the full tab 200 and the electrode sheet 110 under different conditions. For the shape of the solder joints 211, according to the actual situation, such as the distance between adjacent winding turns, the distance between adjacent solder joints 211 in the winding direction Q, etc., the solder joints 211 can be set as square-shaped, dot-shaped, etc. In this embodiment, the dot-shaped is preferably used for convenient spot welding operation. For the diameter range of the solder joints 211, it can be taken as 0.5 to 3 mm.
[0045] It should also be noted that, in order to clearly show the positions of the solder joints 211 in the drawings, the solder joints 211 in all the drawings are represented in the form of hollow dots. The hollow dots are not the actual shapes of the solder joints 211 and should not limit the structural shapes of the solder joints 211.
[0046] An embodiment of the present application provides a battery, including the battery cell welding structure described in any of the above embodiments. It should be noted that since this battery includes the battery cell welding structure described in any of the above embodiments, this battery has beneficial effects similar to or the same as those of the battery cell welding structure. For the specific derivation process of the beneficial effects, please refer to the embodiments of the battery cell welding structure part and will not be elaborated here.
[0047] The above has introduced the embodiments of the present application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.
Claims
1. A battery core welding structure, characterized in that: include: winding body; A full pole ear is formed at the end of the winding body; A current collector, welded to a side of the full pole tab away from the winding body to form a plurality of welding points; Wherein, the plurality of welding points are arranged at equal arc distances along the winding direction of the winding body.
2. The battery core welding structure according to claim 1, characterized in that: The plurality of welding points form a plurality of welding point groups, and the welding points in each welding point group are arranged in an arc shape along the radial direction of the winding body.
3. The battery core welding structure according to claim 2, characterized in that: The plurality of welding point groups are arranged in a spiral shape along the winding direction of the winding body and form at least one spiral track.
4. The battery core welding structure according to claim 3, characterized in that: The winding body includes an inner diameter, an outer diameter and the number of winding turns. When the difference between the outer diameter and the inner diameter is constant, the number and quantity of the spiral track are positively correlated with the number of winding turns; when the number of winding turns is constant, the number and quantity of the spiral track are negatively correlated with the difference between the outer diameter and the inner diameter.
5. The battery core welding structure according to claim 4, characterized in that: The inner diameter ranges from 4 to 7 mm, and / or the outer diameter ranges from 10 to 70 mm, and / or the number of turns of the winding ranges from 20 to 100 turns, and / or along the winding direction of the winding body, the arc distance between two adjacent welding points ranges from 2 to 20 mm.
6. The battery core welding structure according to claim 5, characterized in that: The inner diameter is 5 to 7 mm, the outer diameter is 55 to 65 mm, the number of turns of the winding is 80 to 100 turns, and along the winding direction of the winding body, the arc distance between two adjacent welding points ranges from 3 to 5 mm, the number of the spiral tracks is one, and the number of turns of the spiral track is one.
7. The battery core welding structure according to claim 5, characterized in that: The inner diameter is 5 to 7 mm, the outer diameter is 35 to 45 mm, the number of turns of the winding is 80 to 100 turns, and along the winding direction of the winding body, the arc distance between two adjacent welding points ranges from 3 to 5 mm, the number of spiral tracks is two, and the number of turns of each spiral track is three.
8. The battery core welding structure according to claim 5, characterized in that: The inner diameter is 5 to 7 mm, the outer diameter is 17 to 27 mm, the number of turns of the winding is 80 to 100 turns, and along the winding direction of the winding body, the arc distance between two adjacent welding points ranges from 3 to 5 mm, the number of the spiral tracks is one, and the number of turns of the spiral track is two.
9. The battery core welding structure according to any one of claims 1 to 8, characterized in that: The welding spot is in the shape of a round spot, and the diameter of the welding spot ranges from 0.5 to 3 mm.
10. A battery, characterized in that: The invention comprises a battery core welding structure as claimed in any one of claims 1 to 9.