Battery and production method

Abstract

The present application provides a battery and a production method, wherein the battery has a main structure formed by the coordinated connection of a battery cell and a current collector, the battery cell comprising a wound electrode sheet, a pole ear arranged on the pole sheet being located at the end of the battery cell as it is wound, the current collector being used to connect to the end of the battery cell and matching the shape of the battery cell, the current collector being provided with a connection area, the pole ear being able to abut or weld with the connection area as it is wound with the electrode sheet to achieve an electrically conductive connection, the connection area and the pole ear present a convex and concave matching structure, the positional relationship between the pole ear and the current collector being highly stable, and, compared with the planar coordination of the pole ear and the current collector, the contact area between the pole ear and the current collector is increased, the electrically conductive area is increased to a certain extent, and there is no need to level the connection surface of the pole ear and the current collector by flattening, and the flattening of the pole ear is avoided from the overall structural design, thereby solving the problem in the prior art that cylindrical batteries have a short circuit risk and a low reliability of connection with the current collector due to the flattening of the pole ear during the production process.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery and a production method thereof. Background Art

[0002] In the production and processing of batteries, especially cylindrical batteries, after the positive and negative electrode sheets are wound into a battery cell, the positive and negative electrode ears at both ends are also rolled into a cylindrical shape. In order for the ear to be stably connected to the current collector and maintain good electrical conduction, the ear is usually flattened in the prior art to make the ear have a relatively flat end surface, and then the current collector and the ear are welded. However, during the flattening process, the flattening device and the ear will contact and rub against each other many times, so metal particles will inevitably be generated. The metal particles will contaminate the battery and cause a short circuit risk. In addition, the flattened ear is prone to cold welding during welding, which makes the connection between the ear and the current collector unreliable, affecting the production quality of the battery. Summary of the invention

[0003] In view of this, the present application provides a battery and a production method to solve the problem in the prior art that cylindrical batteries have a short circuit risk and low reliability of connection with current collectors due to flattening of the tabs during the production process.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] A battery comprising:

[0006] The battery cell comprises a wound pole piece with a pole ear at the end;

[0007] A current collector, which matches the shape of the battery core and is provided with a connection area opposite to the battery core and protruding toward the side where the battery core is located;

[0008] The pole tab and the connection area are arranged opposite to each other and connected in the axial direction of the battery cell, and the edge of the pole tab gradually increases along the winding direction so that the pole tab is wound to form a groove matching the connection area.

[0009] Optionally, the connection area is provided with a spiral flange that is raised relative to the current collecting member and is distributed in a spiral manner; wherein,

[0010] The pole lug is fitted on the spiral flange; and / or,

[0011] The pole lugs are distributed along the spiral flange and are fixedly connected to the spiral flange.

[0012] Optionally, it further includes a core shaft located at the axial center of the battery core, both ends of the core shaft are connected to the current collecting parts, and the current collecting parts located at the two ends are symmetrically arranged with respect to the battery core.

[0013] Optionally, the core shaft is provided with an injection channel for injecting electrolyte and a flow hole connected to the injection channel, and the pole ear is provided with injection holes distributed along the winding direction, and the injection holes surround the flow hole and are connected to the flow hole.

[0014] Optionally, the injection channel passes through the current collecting member in the axial direction of the core shaft, and the current collecting member is provided with a sealing plug for sealing the injection channel.

[0015] Optionally, an end cover is provided on a side of the current collecting member opposite to the connection area, and the sealing plug is located in the end cover; an insulating ring for isolating the positive and negative electrodes is provided between the battery cell and the end cover.

[0016] Optionally, the connection area is a conical surface, a circular arc surface, or a parabola.

[0017] Optionally, the pole piece includes a body piece and the pole ear connected to the edge of the body piece; wherein,

[0018] The main body sheet has the same height along the winding direction and the height of the tab gradually increases along the winding direction; or,

[0019] The height of the main body sheet gradually increases along the winding direction and the pole tabs have the same height along the winding direction.

[0020] A production method, applicable to the above-mentioned battery, comprising:

[0021] A core body formed by the driving core shaft, the positive electrode current collector and the negative electrode current collector rotates around the axis of the core shaft;

[0022] The negative electrode sheet, separator, positive electrode sheet and separator stacked in sequence are wound on a core shaft, and the tabs of the positive electrode sheet are rolled onto the spiral flange of the positive electrode collector in turns, and the tabs of the negative electrode sheet are rolled onto the spiral flange of the negative electrode collector in turns to form a battery cell.

[0023] Optionally, while rolling, the tabs of the positive electrode sheet are welded to the spiral flange of the positive electrode current collector, and the tabs of the negative electrode sheet are welded to the spiral flange of the negative electrode current collector.

[0024] The battery provided in the present application is mainly structured by the cooperation and connection of a battery cell and a current collector. The battery cell includes a wound pole sheet, and a pole ear arranged on the pole sheet is located at the end of the battery cell as it is wound. The current collector is used to connect with the end of the battery cell and match the shape of the battery cell. The current collector is provided with a connection area. The pole ear can be abutted or welded to the connection area during the winding process of the pole sheet to achieve electrical conduction connection. The connection area and the pole ear present a convex and concave matching structure. The positional relationship between the pole ear and the current collector is highly stable. Moreover, compared with the pole ear and the current collector in the prior art, The contact area between the pole ear and the current collector is increased in the present solution, the electrical conduction area is increased to a certain extent, and there is no need to level the connection surface between the pole ear and the current collector by flattening. In addition, such a design does not require high dimensional accuracy of the pole ear, and it is easier to accommodate the dimensional error of the pole ear, and the implementation feasibility is high. In summary, the present application avoids flattening the pole ear from the overall structural design, and solves the problem in the prior art that cylindrical batteries have the risk of short circuit and low reliability of connection with the current collector due to flattening of the pole ear during the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0026] Figure 1 A schematic diagram of the structure of a battery provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the positional relationship between the positive electrode sheet, the negative electrode sheet and the electrode tab provided in an embodiment of the present application;

[0028] Figure 3 A schematic diagram of the structure of the core provided in an embodiment of the present application;

[0029] Figure 4 A schematic diagram of the structure of a core body with a conical connection area provided in an embodiment of the present application;

[0030] Figure 5 A schematic diagram of the structure of a core body with a connection area being an arc surface provided in an embodiment of the present application;

[0031] Figure 6 A schematic structural diagram of a core body whose connection area is a parabola provided in an embodiment of the present application.

[0032] exist Figure 1-Figure 6 middle:

[0033] 1. Battery core; 2. Current collector; 3. Mandrel; 4. Sealing plug; 5. End cap; 6. Insulation ring; 7. Adhesive tape; 8. Casing;

[0034] 101, pole piece; 102, pole ear; 103, liquid injection hole; 104, diaphragm;

[0035] 201, connection area; 202, spiral flange;

[0036] 301, liquid injection channel; 302, flow hole. DETAILED DESCRIPTION

[0037] 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 ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] like Figure 1-Figure 3 As shown, an embodiment of the present application provides a battery, which mainly includes a battery cell 1 and a current collector 2. The battery cell 1 includes a wound electrode sheet 101, and a pole ear 102 is provided at the end of the battery cell 1. The current collector 2 matches the shape of the battery cell 1, that is, when the battery cell 1 is wound into a cylindrical shape, the cross-section of the current collector 2 is also circular or approximately circular, and when the battery cell 1 is wound into an elliptical cylinder, the cross-section of the current collector 2 is also elliptical or approximately elliptical. A connection area 201 opposite to the battery cell 1 and protruding toward the side where the battery cell 1 is located is provided on the current collector 2, wherein the pole ear 102 and the connection area 201 are arranged opposite to each other and connected in the axial direction of the battery cell 1, and the edge of the pole ear 102 gradually increases along the winding direction, so that the pole ear 102 is wound to form a groove matching the connection area 201, that is, after the pole ear 102 is wound with the electrode sheet 101, the whole is in the shape of a groove with a depression in the middle and a high peripheral edge.

[0039] In this way, the main structure is formed by the matching connection of the battery cell 1 and the current collector 2. The battery cell 1 includes a wound pole piece 101, and the pole ear 102 arranged on the pole piece 101 is located at the end of the battery cell 1 during the winding. The current collector 2 is used to connect with the end of the battery cell 1 and match the shape of the battery cell 1. The current collector 2 is provided with a connection area 201. The pole ear 102 can abut against the connection area 201 or be fixedly connected with the connection area 201 by welding during the winding process of the pole piece 101 to achieve electrical conduction connection. The connection area 201 and the pole ear 102 present a convex and concave matching structure. The positional relationship between the pole ear 102 and the current collector 2 is highly stable, and the phase Compared with the planar cooperation between the pole ear 102 and the current collector 2 in the prior art, the contact area between the pole ear 102 and the current collector 2 is increased in the present solution, and the electrical conduction area is increased to a certain extent, and there is no need to level the connection surface between the pole ear 102 and the current collector 2 by flattening. In addition, such a design does not require high dimensional accuracy of the pole ear 102, and it is easier to accommodate the dimensional error of the pole ear 102, and the implementation feasibility is high. In summary, the present application avoids flattening the pole ear 102 from the overall structural design, and solves the problem in the prior art that the cylindrical battery has the risk of short circuit and low reliability of connection with the current collector 2 during the production process due to the flattening of the pole ear 102.

[0040] It should be noted that the battery cell 1 is formed by winding the negative electrode sheet 101, the separator 104, the positive electrode sheet 101, and the separator 104 stacked in sequence, and the edges of the negative electrode sheet 101 and the positive electrode sheet 101 are provided with a pole ear 102, the pole ear 102 of the negative electrode sheet 101 is connected to the connection area 201 of the negative electrode current collector 2, and the pole ear 102 of the positive electrode sheet 101 is connected to the connection area 201 of the positive electrode current collector 2. For the convenience of explanation, the pole sheet 101 appearing in this article is any one of the positive electrode sheet 101 and the negative electrode sheet 101, and the current collector 2 is any one of the positive electrode current collector 2 and the negative electrode current collector 2.

[0041] Specifically, the pole tab 102 may be provided as a continuous full pole tab 102 in the winding direction, which is easy to cut.

[0042] The pole piece includes a main body piece and a pole ear connected to the edge of the main body piece. That is to say, the pole piece 101 takes the main body piece as the main structure, and the main body piece is also the area that the diaphragm 104 should cover.

[0043] In a specific embodiment, since the edge of the tab 102 for connecting with the connection area 201 should be gradually high, it can be set that the body sheet is equal in height along the winding direction and is rectangular, and the height of the tab 102 gradually increases along the winding direction; or it can be set that the height of the body sheet gradually increases along the winding direction, and the tab 102 is equal in height along the winding direction and is a parallelogram. In this way, by making any one of the body sheet and the tab 102 have a height change, the purpose of forming a groove at the edge of the tab 102 due to winding can be finally achieved.

[0044] In a preferred embodiment, a spiral flange 202 is provided on the connection area 201, which is raised relative to the current collector 2 and spirally distributed, and the spiral direction of the spiral flange 202 is the same as the winding direction of the battery cell 1; wherein the pole ear 102 is distributed along the spiral flange 202 while being wound with the pole piece 101, and each circle of the pole ear 102 is fitted on the spiral flange 202 corresponding to its position, that is, the edge of the pole ear 102 is pressed on the outer side of each circle of the spiral flange 202 in the radial direction of the current collector 2; or, the pole ear 102 is only distributed along the spiral flange 202 and is welded and fixed to the spiral flange 202; or, the above two methods are implemented simultaneously, that is, when the pole ear 102 is gradually pressed and fitted on the spiral flange 202, the pressed pole ear 102 is welded to the spiral flange 202.

[0045] With such arrangement, the spiral flange 202 provides an attachment position for the pole ear 102 , which not only increases the contact area between the pole ear 102 and the current collector 2 as a whole and optimizes electrical conduction, but also prevents the pole ear 102 from being displaced in the radial direction of the battery cell 1 , which is conducive to making the internal structure of the battery more stable and reliable.

[0046] Furthermore, if Figure 4-Figure 6 As shown, the connection area 201 can be specifically set to be a conical surface, an arc surface or a parabola, that is, from the longitudinal section of the current collector 2, its generatrix is ​​a straight line, an arc line or a parabola, and the current collector 2 is a cone with a thick middle and a thin edge, so as to provide multiple options for production design.

[0047] In a preferred embodiment, the battery is further provided with a core shaft 3 located at the axial center of the battery cell 1, the core shaft 3 is a hard insulator, both ends of the core shaft 3 are connected with current collectors 2, and the current collectors 2 located at both ends are symmetrically arranged with respect to the battery cell 1, that is, the positive current collector 2 and the negative current collector 2 are mirror-symmetrically arranged.

[0048] With such arrangement, the core shaft 3 provides attachment for the winding of the pole piece 101, which not only enables the pole piece 101 to be wound according to the preset conditions with high dimensional accuracy, but also makes the structure of the battery cell 1 stable after forming. In addition, the stable connection between the core shaft 3 and the positive electrode current collector 2 and the negative electrode current collector 2 further optimizes the stability of the internal structure of the battery.

[0049] In a specific embodiment, an injection channel 301 for injecting electrolyte is provided in the core shaft 3 along its axial direction, and a plurality of flow holes 302 connected to the injection channel 301 are provided on the side wall of the core shaft 3, and injection holes 103 distributed with variable pitches along the winding direction are provided on the pole ear 102, and the injection holes 103 surround the flow holes 302 and are connected to the flow holes 302, so that the electrolyte enters the core shaft 3 from the injection channel 301, and then flows into the battery cell 1 through the flow holes 302, and gradually fills the entire battery cell 1 under the conduction effect of the injection holes 103. In order to optimize the speed of electrolyte injection, it is preferred to arrange flow holes 302 at positions close to the positive current collector 2 and the negative current collector 2 of the core shaft 3, and injection holes 103 are provided on the corresponding tabs 102 of the positive electrode sheet 101 and the negative electrode sheet 101; it is preferred that, when the main body sheet is of equal height along the winding direction and the height of the tabs 102 gradually increases along the winding direction, a row of flow holes 302 opposite to the injection holes 103 are arranged in the radial extension direction of any injection hole 103; when the height of the main body sheet gradually increases along the winding direction and the tabs 102 are of equal height along the winding direction, a row of flow holes 302 corresponding to one of the injection holes 103 is gradually raised from the inside to the outside.

[0050] Furthermore, a liquid injection channel 301 is provided to penetrate the current collector 2 in the axial direction of the mandrel 3, and a sealing plug 4 is provided on the current collector 2 to seal the liquid injection channel 301. Specifically, one of the positive current collector 2 and the negative current collector 2 is provided with an opening of the liquid injection channel 301 and is detachably connected to the sealing plug 4, and the other is sealed at the end, that is, single-side liquid injection. Such a configuration facilitates the process of injecting electrolyte during the production and processing of the battery, and is easy to seal, thereby optimizing the production process.

[0051] In addition, the side of the current collector 2 opposite to the connection area 201 is flat and provided with an end cap 5. An insulating ring 6 for isolating the positive and negative electrodes is provided between the battery cell 1 and the end cap 5. The insulating ring 6 is sleeved around the edge of the end cap 5 and the battery cell 1, and surrounds the outer periphery of the pole ear 102, and the sealing plug 4 is embedded in the end cap 5. In this way, the end cap 5 covers the current collector 2, providing a good connection position for the insulating ring 6 without interfering with the pole ear 102.

[0052] In addition, the battery core 1 is circumferentially coated with adhesive tape 7 to reinforce the battery core 1 and prevent it from falling apart.

[0053] The assembly formed by the above structures is enclosed in the outer shell 8, completing the production and processing of the battery.

[0054] Based on the above battery, the present application embodiment further provides a production method, which is applicable to the above battery, and the method comprises:

[0055] The core body formed by the driving core shaft 3, the positive electrode current collector 2 and the negative electrode current collector 2 rotates around the axis of the core shaft 3;

[0056] The negative electrode sheet 101, the separator 104, the positive electrode sheet 101, and the separator 104 stacked in sequence are wound on the core shaft 3, and the pole ear 102 of the positive electrode sheet 101 is rolled circle by circle on the spiral flange 202 of the positive electrode collector 2, and the pole ear 102 of the negative electrode sheet 101 is rolled circle by circle on the spiral flange 202 of the negative electrode collector 2 to form a battery cell 1.

[0057] Furthermore, while rolling, the tab 102 of the positive electrode sheet 101 is welded to the spiral flange 202 of the positive electrode current collector 2 , and the tab 102 of the negative electrode sheet 101 is welded to the spiral flange 202 of the negative electrode current collector 2 .

[0058] It should be noted that rolling is achieved by a pressure wheel, and there is a welding device near the pressure wheel. As the winding proceeds, the pressure wheel and the welding device gradually move radially outward along with the pole lug 102 and gradually move axially toward the direction close to the current collecting member 2 to match the pole lug 102.

[0059] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0060] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0061] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0062] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0063] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present application.

[0064] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A battery, characterized in that: include: The battery cell comprises a wound pole piece with a pole ear at the end; A current collector, which matches the shape of the battery cell and is symmetrically arranged at both ends of the battery cell, and is provided with a connection area opposite to the battery cell and protruding toward the side where the battery cell is located, and the connection area is provided with a spiral flange protruding relative to the current collector and distributed in a spiral manner; Among them, the pole ear and the connecting area are arranged opposite to each other and connected in the axial direction of the battery cell, the edge of the pole ear gradually increases along the winding direction, so that the pole ear is wound to form a groove matching the connecting area, and the pole ear is distributed along the spiral flange while being wound with the pole piece, and each circle of the pole ear is fitted on the spiral flange corresponding to it, and or the pole ear is distributed along the spiral flange and fixed to the spiral flange.

2. The battery according to claim 1, characterized in that It also includes a core shaft located at the axial center of the battery core, both ends of the core shaft are connected to the current collecting parts, and the current collecting parts located at the two ends are symmetrically arranged with respect to the battery core.

3. The battery according to claim 2, characterized in that The core shaft is provided with an injection channel for injecting electrolyte and a flow hole connected to the injection channel, and the pole ear is provided with injection holes distributed along the winding direction, and the injection holes surround the flow hole and are connected to the flow hole.

4. The battery according to claim 3, characterized in that The injection channel passes through the current collecting member in the axial direction of the core shaft, and a sealing plug for sealing the injection channel is provided on the current collecting member.

5. The battery according to claim 4, characterized in that An end cover is provided on one side of the current collector opposite to the connection area, and the sealing plug is located in the end cover; an insulating ring for isolating the positive and negative electrodes is provided between the battery cell and the end cover.

6. The battery according to claim 1, characterized in that The connection area is a conical surface, a circular arc surface or a parabola.

7. The battery according to claim 1, characterized in that The pole piece includes a body piece and the pole ear connected to the edge of the body piece; wherein, The main body sheet has the same height along the winding direction and the height of the tab gradually increases along the winding direction; or, The height of the main body sheet gradually increases along the winding direction and the pole tabs have the same height along the winding direction.

8. A production method, characterized in that: Applicable to the battery of claim 2, the method comprising: A core body formed by the driving core shaft, the positive electrode current collector and the negative electrode current collector rotates around the axis of the core shaft; The negative electrode sheet, separator, positive electrode sheet and separator stacked in sequence are wound on a core shaft, and the tabs of the positive electrode sheet are rolled onto the spiral flange of the positive electrode collector in turns, and the tabs of the negative electrode sheet are rolled onto the spiral flange of the negative electrode collector in turns to form a battery cell.

9. The production method according to claim 8, characterized in that: While rolling, the tabs of the positive electrode sheet are welded to the spiral flange of the positive electrode current collector, and the tabs of the negative electrode sheet are welded to the spiral flange of the negative electrode current collector.

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