Battery and production method

Abstract

The present application provides a battery and a production method, the main structure of which is formed by the coordinated connection of a battery cell and a current collector, the battery cell includes a wound pole piece, and a plurality of sub-pole ears arranged on the pole piece are located at the end of the battery cell as the winding progresses, the current collector is used to connect with the end of the battery cell and match the shape of the battery cell, and the current collector is provided with multiple layers for connecting partitions corresponding to each segment of the sub-pole ears one by one, and each segment of the sub-pole ears can be surrounded and fixed on the corresponding connecting partition as the pole piece is wound, and when the sub-pole ears are fixed around the connecting partition, the gap between the teeth allows two adjacent teeth to approach. With such a configuration, the electrical conduction connection between the pole ears and the current collector in the battery production is achieved by the plurality of sub-pole ears surrounding the corresponding connecting partition and being fixed to the corresponding connecting partition, and the overall structural design avoids flattening the pole ears, and solves the problem in the prior art that the cylindrical battery has a short circuit risk and a low reliability of connection with the current collector due to the flattening of the pole ears 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, the end of which is provided with a plurality of pole ears spaced apart along the winding direction;

[0007] A current collector, which matches the shape of the battery cell and is provided with multi-layer stepped annular connection partitions;

[0008] Among them, each section of the sub-pole ear is correspondingly wound on a layer of the connecting partition, and each section of the sub-pole ear includes a plurality of teeth distributed along the winding direction, and there is a gap between any two adjacent teeth so that when the sub-pole ear is fixed around the corresponding connecting partition, the two adjacent teeth are close to each other.

[0009] Optionally, the connection partition is the circumferential side wall area of ​​the current collecting member, each section of the pole ear is wound multiple times in the corresponding connection partition, and the height of the tooth sheet gradually increases along the winding direction so that the connection area of ​​the pole ears of each circle when approaching the corresponding connection partition is not less than a preset area.

[0010] Optionally, the tooth piece is trapezoidal so that the gap is a gradually expanding gap.

[0011] Optionally, the edge of the pole piece is composed of an inner region without a pole lug, multiple segments of the pole lugs, and an outer region without a pole lug in sequence along the winding direction.

[0012] Optionally, 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 both ends are symmetrically arranged about the battery core, and each layer of the connection partitions is coaxially distributed with the core shaft as the center.

[0013] Optionally, the core shaft is provided with an injection channel for injecting electrolyte and a flow hole connected to the injection channel, and each section of the sub-electrode 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 collector opposite to the battery cell, 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 battery core is circumferentially coated with adhesive tape.

[0017] A production method, applicable to the above-mentioned battery, comprising:

[0018] 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;

[0019] Winding the stacked negative electrode sheet, separator, positive electrode sheet and separator on a mandrel, rolling each segment of the positive electrode sheet on the corresponding connection partition of the positive electrode collector, and rolling each segment of the negative electrode sheet on the corresponding connection partition of the negative electrode collector, to form a battery cell;

[0020] Each segment of the sub-electrode tab of the positive electrode sheet is welded to the corresponding connecting section of the positive electrode current collector, and each segment of the sub-electrode tab of the negative electrode sheet is welded to the corresponding connecting section of the negative electrode current collector.

[0021] The battery provided in the present application has a main structure formed by the coordinated connection between a battery cell and a current collector. The battery cell includes a wound electrode sheet. A plurality of sub-electrode ears arranged on the electrode sheet are located at the end of the battery cell as the electrode sheet is wound. The current collector is used to connect to the end of the battery cell and match the shape of the battery cell. A plurality of layers are provided on the current collector for connecting partitions corresponding to each sub-electrode ear one by one. Each sub-electrode ear can be surrounded and fixed on the corresponding connecting partition as the electrode sheet is wound. When the sub-electrode ears are fixed around the connecting partition, the gap between the teeth allows two adjacent teeth to approach each other. In this way, the electrical connection between the pole ear and the current collector in battery production is achieved by surrounding the corresponding connection partition with multiple segments of sub-pole ears and fixing them to the corresponding connection partition. Since the sub-pole ears are not a structure that is continuous throughout, when they are attached to the connection partition, even if the ring-shaped sub-pole ears will naturally gather inward, the gaps between the teeth will provide space for the teeth to approach each other, ensuring that no scratches occur between adjacent teeth, thereby avoiding the generation of metal particles to a great extent. Moreover, each tooth piece is flat and fitted, and each segment of the sub-pole ear has a stable and good surface contact with the corresponding connection partition. After fixing, the two are reliably connected and have good electrical conduction. The overall structural design avoids flattening the pole ears, thereby solving the problem in the prior art that cylindrical batteries have a short circuit risk and a low reliability in connection with the current collector due to flattening of the pole ears during the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 A schematic diagram of the structure of a battery provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of the structure of the pole piece and the pole ear provided in the embodiment of the present application;

[0025] Figure 3 A schematic diagram of the structure of the core provided in an embodiment of the present application.

[0026] exist Figure 1-Figure 3 middle:

[0027] 1. Battery core; 2. Current collector; 3. Mandrel; 4. Sealing plug; 5. End cap; 6. Insulation ring; 7. Adhesive tape; 8. Casing;

[0028] 101, pole piece; 102, pole ear; 103, liquid injection hole;

[0029] 201. Connect partitions;

[0030] 301, liquid injection channel; 302, flow hole;

[0031] 1021. Gear. DETAILED DESCRIPTION

[0032] 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.

[0033] like Figure 1-Figure 3 As shown, the 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 the end of the battery cell 1 is provided with a plurality of segmented electrode ears 102 spaced apart along the winding direction. 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. When the battery cell 1 is wound into an elliptical column, the cross section of the current collector 2 is also elliptical or approximately elliptical. A multi-layer stepped annular connecting partition 201 is provided, wherein the overall height of each segment of the pole ear 102 along the winding direction gradually increases, each segment of the pole ear 102 is correspondingly wound on a layer of the connecting partition 201, and each segment of the pole ear 102 includes a plurality of teeth 1021 distributed along the winding direction, and there is a gap between any two adjacent teeth 1021 so that when the pole ear 102 is fixed around the corresponding connecting partition 201, the two adjacent teeth 1021 are close to each other.

[0034] In this way, the main structure is formed by the coordinated connection between the battery cell 1 and the current collector 2. The battery cell 1 includes a wound electrode sheet 101. A plurality of sub-electrode ears 102 arranged on the electrode sheet 101 are located at the end of the battery cell 1 as it is wound. The current collector 2 is used to connect to the end of the battery cell 1 and match the shape of the battery cell 1. A plurality of layers of connection partitions 201 corresponding to each segment of the sub-electrode ears 102 are provided on the current collector 2. Each segment of the sub-electrode ears 102 can be surrounded and fixed on the corresponding connection partition 201 as it is wound on the electrode sheet 101. When the sub-electrode ears 102 are fixed around the connection partition 201, the gap between the teeth 1021 allows two adjacent teeth 1021 to approach each other. In this way, the electrical connection between the pole ear and the current collector 2 in the battery production is achieved by surrounding the corresponding connection partition 201 with multiple segments of sub-pole ears 102 and fixing them to the corresponding connection partition 201. Since the sub-pole ears 102 are not a structure that is continuous throughout, when they are attached to the connection partition 201, even if the ring-shaped sub-pole ears 102 will naturally retract inward, the gaps between the teeth 1021 will provide space for the teeth 1021 to approach each other, ensuring that no scratches occur between adjacent teeth 1021, thereby avoiding the generation of metal particles to a great extent. Moreover, each tooth piece 1021 is flat and fitted, and each segment of the sub-pole ear 102 has a stable and good surface contact with the corresponding connection partition 201. After fixing, the two are reliably connected and have good electrical conduction. The overall structural design avoids flattening the pole ears, thereby solving the problem in the prior art that cylindrical batteries have a short circuit risk and a low reliability in connection with the current collector 2 due to the flattening of the pole ears during the production process.

[0035] It should be noted that the battery cell 1 is formed by sequentially stacking a negative electrode sheet 101, a separator, a positive electrode sheet 101, and winding a separator. The edges of the negative electrode sheet 101 and the positive electrode sheet 101 are provided with multiple sub-electrode ears 102. All sub-electrode ears 102 of the negative electrode sheet 101 are correspondingly connected to the connection partition 201 of the negative electrode current collector 2, and all sub-electrode ears 102 of the positive electrode sheet 101 are correspondingly connected to the connection partition 201 of the positive electrode current collector 2. For the convenience of explanation, the electrode sheet 101 mentioned in this article refers to any one of the positive electrode sheet 101 and the negative electrode sheet 101, and the current collector 2 refers to any one of the positive electrode current collector 2 and the negative electrode current collector 2.

[0036] In a specific embodiment, the connection partition 201 is the circumferential side wall area of ​​the current collecting part 2, or the connection partition 201 is the side of a cylinder, and each segment of the pole ear 102 is wound multiple times in the corresponding connection partition 201, and the height of the tooth 1021 gradually increases along the winding direction, so that the connection area of ​​each circle of the pole ears 102 when approaching the corresponding connection partition 201 is not less than a preset area. The preset area here refers to the effective area that can play an electrical conduction role, or in other words, when each circle of the pole ears 102 is surrounded by the connection partition 201, the pole ears 102 fall within the area of ​​the connection partition 201 extending parallel to the outside.

[0037] With such arrangement, each segment of the pole ear 102 is wound multiple times in the corresponding connection partition 201, which can make the connection between the battery cell 1 and the current collector 2 more stable, and further strengthen the current collecting effect and electrical conduction; on the basis of the above, since in actual conditions, the thickness of the pole ear is smaller than the thickness of the pole piece 101, then the segment of the pole ear 102 located on the outer circle needs to move closer to the inside when it is attached to the segment of the pole ear 102 on the inner side, which will consume a part of the height dimension to achieve it, so the height of the tooth piece 1021 gradually increases along the winding direction to compensate for this part of the dimension consumption, so that there is sufficient contact area between the segment of the pole ear 102 on the outer circle and the segment of the pole ear 102 on the inner circle to ensure that the preset area is met.

[0038] It should be noted that the two adjacent sections of the pole ears 102 are divided into an inner section and an outer section, wherein the height of the first tooth piece 1021 of the outer section is lower than the height of the last tooth piece 1021 of the inner section, and the height of the nth tooth piece 1021 of the outer section is higher than the height of the corresponding nth tooth piece 1021 of the inner section to match the step size of the current collecting component 2.

[0039] In a specific embodiment, the tooth piece 1021 is set to be trapezoidal, preferably an isosceles trapezoid, with an upper bottom as an edge and a lower bottom integrally connected to the pole piece 101, so that the gap is a gradually expanding gap. The gap is formed by cutting the originally continuous pole ear structure. In addition, the inclination angles on both sides of the tooth piece 1021, the width of the upper bottom of the tooth piece 1021, and the height of the tooth piece 1021 are adjusted with the length and position of the pole piece 101, ensuring that when the pole ear 102 is connected to the connecting partition 201, adjacent tooth pieces 1021 do not scratch each other and match the diameter size of the current collector 2.

[0040] In another preferred embodiment, the edge of the pole piece 101 is provided with a non-electrode inner area, a multi-segmented pole lug 102, and a non-electrode outer area in the winding direction, that is, on the edge of the pole piece 101, there is a part of the area without pole lugs on the inner and outer sides of the integral pole lug composed of the multi-segmented pole lug 102. The pole lug 102 extends out of the diaphragm covering area on the pole piece 101, and the non-electrode inner area and the non-electrode outer area are in the diaphragm covering area and maintain a certain insulation distance.

[0041] With such arrangement, during the entire process of winding the pole piece 101, first only the pole piece 101 in the inner area without the pole ear is wound. After winding to a certain extent, the radial dimension thereof can provide a larger winding circumference for the sub-pole ear 102, thereby preventing the sub-pole ear 102 from being excessively curled and damaging the structure due to the small inner diameter at the beginning of winding. After the winding of all the sub-pole ears 102 is completed, the pole piece 101 in the outer area without the pole ear is finally wound several times, and the battery cell 1 is formed. The outer periphery of the overall pole ear is wrapped and reinforced with several turns of the pole piece 101, which is beneficial to the structural stability of the sub-pole ear 102.

[0042] 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.

[0043] 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.

[0044] 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 each segment of the pole ear 102 is provided with an injection hole 103 distributed with a variable pitch along the winding direction, 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 provide flow holes 302 at positions close to the positive current collector 2 and the negative current collector 2 of the core shaft 3, and correspondingly, each segment of the positive electrode sheet 101 and the negative electrode sheet 101 is provided with an injection hole 103 on the tabs 102; it is preferred to arrange that, in the radial extension direction of any injection hole 103 along the battery cell 1, a row of flow holes 302 opposite to the injection hole 103 are arranged.

[0045] Furthermore, a liquid injection channel 301 is provided to penetrate the current collector 2 in the axial direction of the core shaft 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 blocked. 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.

[0046] Moreover, the side of the current collector 2 opposite to the battery cell 1 is a plane, that is, the current collector 2 is a multi-layer boss with a gradually increasing diameter, and an end cap 5 is provided on the plane. 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 integral pole ear, 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 that does not interfere with the integral pole ear.

[0047] 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.

[0048] The assembly formed by the above structures is enclosed in the outer shell 8, completing the production and processing of the battery.

[0049] 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:

[0050] 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;

[0051] The negative electrode sheet 101, the separator, the positive electrode sheet 101, and the separator stacked in sequence are wound on the mandrel 3, and the segmented pole tabs 102 of the positive electrode sheet 101 are rolled circle by circle on the corresponding connection partition 201 of the positive electrode current collector 2, and the segmented pole tabs 102 of the negative electrode sheet 101 are rolled circle by circle on the corresponding connection partition 201 of the negative electrode current collector 2 to form a battery cell 1;

[0052] Each segment of the sub-electrode tab 102 of the positive electrode sheet 101 is welded to the corresponding connecting partition 201 of the positive electrode current collector 2 , and each segment of the sub-electrode tab 102 of the negative electrode sheet 101 is welded to the corresponding connecting partition 201 of the negative electrode current collector 2 .

[0053] 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 as the outer diameter of the pole ear 102 increases to match the pole ear 102. In addition, welding can be performed once for each rolling of the pole ear 102, or welding can be performed after the rolling is completed.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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: A battery cell comprises a wound pole piece, wherein the end edge of the pole piece is provided with a pole-free inner area, a plurality of pole-free poles arranged at intervals, and a pole-free outer area in sequence along the winding direction; A current collector, which matches the shape of the battery core and is provided with a multi-layer stepped annular connection partition, wherein the connection partition is a circumferential side wall area of ​​the current collector; Among them, the multiple layers of the connecting partitions are connected to the sub-pole ears in a one-to-one correspondence, each section of the sub-pole ears is correspondingly wound on a layer of the connecting partition, each section of the sub-pole ears is wound multiple times in the corresponding connecting partition, and each section of the sub-pole ears includes a plurality of teeth distributed along the winding direction, and the height of the teeth gradually increases along the winding direction. There is a gap between any two adjacent teeth so that when the sub-pole ears are fixed around the corresponding connecting partition, the two adjacent teeth are close to each other, so that the connection area of ​​the sub-pole ears of each circle when they are close to the corresponding connecting partition is not less than the preset area.

2. The battery according to claim 1, characterized in that The tooth piece is trapezoidal, so that the gap is a gradually expanding gap.

3. 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 both ends are symmetrically arranged about the battery core, and each layer of the connection partitions is coaxially distributed with the core shaft as the center.

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

5. The battery according to claim 4, 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.

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

7. The battery according to claim 1, characterized in that The battery core is circumferentially coated with adhesive paper.

8. A production method, characterized in that: Applicable to the battery according to any one of claims 1 to 7, 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; Winding the stacked negative electrode sheet, separator, positive electrode sheet and separator on a mandrel, rolling each segment of the positive electrode sheet on the corresponding connection partition of the positive electrode collector, and rolling each segment of the negative electrode sheet on the corresponding connection partition of the negative electrode collector, to form a battery cell; Each segment of the sub-electrode tab of the positive electrode sheet is welded to the corresponding connecting section of the positive electrode current collector, and each segment of the sub-electrode tab of the negative electrode sheet is welded to the corresponding connecting section of the negative electrode current collector.

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