Multi-tab cylindrical lithium battery

Abstract

The utility model relates to the technical field of lithium batteries, in particular to a multi-tab cylindrical lithium battery, which comprises a roll core and an anode current collector, the anode current collector is arranged at the anode end of the roll core, an insulating pad is arranged between the roll core and the anode current collector to isolate the anode current collector from being contacted with the roll core, a plurality of anode tabs are arranged at the anode end of the roll core, and the anode tabs are connected with the roll core. Each positive lug penetrates through the insulation pad to be welded with the positive current collector, the insulation pad is provided with a flow channel communicated with the central hole of the roll core, the positive current collector is provided with a flow guide gap penetrating through the opposite surface of the positive current collector, and the flow channel is communicated with a liquid injection hole of the battery through the flow guide gap. According to the multi-tab cylindrical lithium battery, the conduction area of current can be effectively increased, the internal resistance of the battery is reduced, meanwhile, the time for electrolyte to enter the roll core can be shortened, and the electrolyte injection efficiency of the battery is improved.

Description

Technical Field

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

[0002] At present, the positive pole ear of the traditional cylindrical lithium-ion battery usually adopts a full-pole ear structure (the full-pole ear is a battery technology. The conductive lead-out parts of the positive and negative electrodes of the battery (i.e., the pole ears) are no longer welded at both ends separately like traditional batteries, but the entire surface is used as the pole ears). For example, a full-pole ear battery cell structure disclosed in a Chinese patent (Announcement No.: CN115051123B) adopts a full-pole ear solution. Although it can increase the current conduction area, it can achieve the effect of reducing the internal resistance of the battery.

[0003] However, since the core package (winding core) of the above-mentioned battery cell needs to be flattened after winding, and the flattened full pole ear covers the positive end of the winding core, it is difficult for the electrolyte to penetrate into the interior of the winding core during injection, which greatly increases the injection time and affects the battery injection efficiency.

[0004] In addition, in the process of flattening the entire tab, some crushed particles will appear. These crushed particles may enter the positive or negative terminal of the battery, causing a short circuit in the battery. Utility Model Content

[0005] One of the main purposes of the utility model is to provide a multi-electrode cylindrical lithium battery, which can effectively increase the current conduction area and reduce the internal resistance of the battery. At the same time, it can also reduce the time for the electrolyte to enter the interior of the winding core and improve the battery injection efficiency.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a multi-electrode cylindrical lithium battery, including a winding core and a positive current collector, wherein the positive current collector is arranged at the positive end of the winding core, an insulating pad is arranged between the winding core and the positive current collector to isolate the positive current collector from contact with the winding core, a plurality of positive ears are arranged at the positive end of the winding core, each of the positive ears passes through the insulating pad and is welded to the positive current collector, a flow channel communicating with the central hole of the winding core is opened on the insulating pad, and a guide gap is opened on the positive current collector that runs through the opposite surface of the positive current collector, and the guide gap connects the flow channel with the injection hole of the battery.

[0007] Furthermore, a plurality of positive ears are provided on opposite sides of the positive end of the winding core, the plurality of positive ears on one side of the positive end of the winding core are set as a first positive ear group, and the plurality of positive ears on the other side of the positive end of the winding core are set as a second positive ear group, the first positive ear group and the second positive ear group are separated by the positive current collector, the surface of the positive current collector facing away from the insulating pad is divided into a first welding area and a second welding area by the guide gap, the plurality of positive ears of the first positive ear group are welded to the first welding area, and the plurality of positive ears of the second positive ear group are welded to the second welding area.

[0008] Furthermore, two guide slits are provided, the first ends of the two guide slits do not penetrate the first end surface of the positive electrode collector, and the second ends of the two guide slits penetrate the second end surface of the positive electrode collector, so that the positive electrode collector can be bent at the position between the two guide slits.

[0009] Furthermore, the number of positive electrode tabs in the first positive electrode tab group is the same as the number of positive electrode tabs in the second positive electrode tab group.

[0010] Furthermore, the first positive electrode tab group and the second positive electrode tab group are mirror-symmetric with respect to the positive electrode current collector.

[0011] Furthermore, two opposite sides of the insulating pad are respectively provided with air-avoiding grooves for avoiding the first positive electrode tab group and the second positive electrode tab group.

[0012] Furthermore, a groove is provided on the surface of the insulating pad facing away from the winding core, and the positive electrode current collector is embedded in the groove.

[0013] Furthermore, a surface of the positive electrode current collector facing away from the insulating pad is flush with a surface of the insulating pad facing away from the winding core.

[0014] Furthermore, the insulating pad is provided with a plurality of through holes penetrating the opposite surface thereof and located outside the groove.

[0015] Furthermore, a through hole is provided at each of the four corners of the insulating pad.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] When the multi-electrode ear cylindrical lithium battery of the utility model is in use, the insulating pad is used to isolate the contact between the winding core and the positive electrode collector to prevent short circuit and ensure the safety of the battery; the positive end of the winding core is welded to the positive electrode collector through multiple positive ears, which increases the current conduction area and reduces the internal resistance of the battery; at the same time, the flow channel on the insulating pad and the injection hole of the battery are connected by the guide gap on the positive electrode collector, and the flow channel is connected with the central hole of the winding core. Therefore, during the battery injection process, the electrolyte flows from the position of the battery injection hole into the guide gap, the flow channel, and the central hole of the winding core in sequence, and then enters the interior of the winding core, ensuring that the electrolyte enters the interior of the winding core smoothly, reducing the time for the electrolyte to enter the interior of the winding core, and improving the battery injection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a winding core involved in an embodiment;

[0019] Figure 2 The embodiment relates to a structural schematic diagram of the connection between the winding core and the insulating pad;

[0020] Figure 3 Schematic diagram of the structure of the connection between the winding core, the insulating pad and the positive electrode current collector involved in the embodiment;

[0021] Figure 4 is a schematic diagram of the structure of an insulating pad related to an embodiment;

[0022] Figure 5 It is a schematic structural diagram of an insulating pad from another angle according to an embodiment;

[0023] Figure 6 is a schematic diagram of the structure of the positive electrode current collector involved in the embodiment;

[0024] Figure 7 Schematic diagram of the structure of the positive electrode current collector according to another embodiment.

[0025] Reference numerals in the accompanying drawings:

[0026] 1. winding core; 10. positive electrode ear; 101. first positive electrode ear group; 102. second positive electrode ear group; 103. center hole; 2. insulating pad; 20. air avoidance groove; 21. flow channel; 22. groove; 23. fan-shaped block; 24. through hole; 3. positive electrode current collector; 30. guide gap. DETAILED DESCRIPTION

[0027] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] In the description of the present invention, it should be understood that the terms "width", "up", "down", "front", "back", "top", "bottom", etc. indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "set" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] In the present utility model, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature in which they are in contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] Please refer to Figure 1 - Figure 7 The utility model provides a multi-electrode cylindrical lithium battery.

[0032] Reference Figure 1The multi-electrode cylindrical lithium battery comprises a winding core 1, an insulating pad 2 and a positive electrode collector 3. The winding core 1 is formed by winding a rectangular positive electrode sheet, a negative electrode sheet and an insulating separator between the positive electrode sheet and the negative electrode sheet. Since the production of the winding core 1 belongs to the conventional technology in the field of lithium batteries, it will not be described here; the positive end of the winding core 1 is provided with a plurality of positive electrodes 10, and the opposite sides of the positive end of the winding core 1 are provided with a plurality of positive electrodes 10. The plurality of positive electrodes 10 on one side of the positive end of the winding core 1 are set as a first positive electrode ear group 101, and the plurality of positive electrodes 10 on the other side of the positive end of the winding core 1 are set as a second positive electrode ear group 102; each positive electrode ear 10 is welded to the positive electrode collector 3. The first positive electrode ear group 101 and the second positive electrode ear group 102 have the same structure, and the number of positive electrodes 10 in the first positive electrode ear group 101 is the same as the number of positive electrodes 10 in the second positive electrode ear group 102, which is conducive to uniform current conduction on the opposite sides of the positive end of the winding core 1.

[0033] Reference Figure 2 , Figure 4 and Figure 5 The insulating pad 2 is fixed on the positive terminal end face of the winding core 1, and opposite sides of the insulating pad 2 are respectively provided with air avoidance grooves 20 for avoiding the first positive electrode ear group 101 and the second positive electrode ear group 102. The air avoidance grooves 20 penetrate the opposite surfaces of the insulating pad 2, and the air avoidance grooves 20 extend along the horizontal X direction, so that the first positive electrode ear group 101 and the second positive electrode ear group 102 pass through the insulating pad 2 through the two air avoidance grooves 20 and are welded to the positive electrode current collector 3. In addition, a groove 22 is provided on the surface of the insulating pad 2 facing away from the winding core 1; a flow channel 21 communicating with the central hole 103 of the winding core 1 is also provided on the insulating pad 2, that is, a flow channel 21 communicating with the central hole 103 of the winding core 1 is provided in the groove 22, and the flow channel 21 extends along the horizontal Y direction. The flow channel 21 is a rectangular groove, and the inner diameter of the flow channel 21 is smaller than the inner diameter of the central hole 103 of the battery, which is beneficial for the electrolyte to enter the central hole 103 of the battery; one end of the flow channel 21 passes through one end face of the insulating pad 2, and the other end of the flow channel 21 does not pass through the other end face of the insulating pad 2.

[0034] Reference Figure 2 , Figure 4 and Figure 5 The groove 22 and the two avoidance grooves 20 on the insulating pad 2 form fan-shaped blocks 23 at the four corners of the insulating pad 2. The insulating pad 2 is provided with a plurality of through holes 24 penetrating the opposite surfaces thereof, and each through hole 24 is located outside the groove 22. Specifically, a through hole 24 is provided at each of the four corners of the insulating pad 2, that is, each fan-shaped block 23 is provided with a through hole 24.

[0035] Reference Figure 3 , Figure 6 and Figure 7, the positive current collector 3 is arranged at the positive end of the winding core 1. Specifically, the positive current collector 3 is embedded in the groove 22 of the insulating pad 2, and the surface of the positive current collector 3 facing away from the insulating pad 2 is flush with the surface of the insulating pad 2 facing away from the winding core 1. In this way, the positive current collector 3 can be prevented from protruding outside the insulating pad 2 and occupying space, which is beneficial to improving the energy density of the battery. In addition, the positive current collector 3 is provided with a guide gap 30 that runs through its relative surface. The guide gap 30 is correspondingly connected to the flow channel 21. The flow channel 21 is connected to the injection hole of the battery (not shown) through the guide gap 30, so that the electrolyte can enter the central hole 103 of the winding core 1 from the guide gap 30 and the flow channel 21 in turn, ensuring that the electrolyte smoothly enters the interior of the winding core 1.

[0036] The positive electrode current collector 3 is made of aluminum.

[0037] It should be noted that since the surface of the positive current collector 3 facing away from the insulating pad 2 is flush with the surface of the insulating pad 2 facing away from the winding core 1, and there are through holes 24 at the four corners of the insulating pad 2, when the electrolyte enters the surface of the positive current collector 3, a part of it will enter the central hole 103 of the winding core 1 through the guide gap 30, and the other part will flow from the surface of the positive current collector 3 to each through hole 24, and then enter various parts of the battery through each through hole 24, diffusing the electrolyte into the battery, further improving the efficiency of the electrolyte penetrating into the winding core 1.

[0038] Reference Figure 3 , Figure 6 and Figure 7 In this embodiment, two guide slits 30 are provided, and the first ends of the two guide slits 30 do not penetrate the first end surface of the positive electrode collector 3, and the second ends of the two guide slits 30 penetrate the second end surface of the positive electrode collector 3, so that the positive electrode collector 3 can be bent at the position between the two guide slits 30 to form a bent portion, which is conducive to the connection between the positive electrode collector 3 and the battery shell. In addition, the surface of the positive electrode collector 3 facing away from the insulating pad 2 is divided into a first welding area and a second welding area by the guide slits 30. The multiple positive electrodes 10 of the first positive electrode ear group 101 are welded to the first welding area, and the multiple positive electrodes 10 of the second positive electrode ear group 102 are welded to the second welding area. In this way, the welding positions of the first positive electrode ear group 101 and the second positive electrode ear group 102 with the positive electrode collector 3 can be distinguished.

[0039] It should be noted that the lengths of the multiple positive tabs 10 of the first positive tab group 101 and the second positive tab group 102 increase successively from the inner circle to the outer circle of the winding core 1. Therefore, the multiple positive tabs 10 of the first positive tab group 101 can be welded to the first welding area, and the multiple positive tabs 10 of the second positive tab group 102 can be welded to the second welding area.

[0040] Since the positive electrode current collector 3 is located in the groove 22 of the insulating pad 2, and the first positive electrode ear group 101 and the second positive electrode ear group 102 respectively pass through the two grooves 22 of the insulating pad 2 and are welded to the positive electrode current collector 3, the first positive electrode ear group 101 and the second positive electrode ear group 102 are separated by the positive electrode current collector 3. In order to facilitate the welding of the first positive electrode ear group 101 and the second positive electrode ear group 102 with the positive electrode current collector 3, the first positive electrode ear group 101 and the second positive electrode ear group 102 of this embodiment are mirror-symmetric about the positive electrode current collector 3. In other embodiments, the first positive electrode ear group 101 and the second positive electrode ear group 102 can also be staggered.

[0041] In summary, the multi-electrode ear cylindrical lithium battery of the utility model is isolated from contact between the core 1 and the positive current collector 3 by setting an insulating pad 2 between the core 1 and the positive electrode collector 3, thereby preventing short circuit and ensuring the safety of the battery; in addition, the positive end of the core 1 is welded to the positive electrode collector 3 by multiple positive ears 10 on both sides, thereby increasing the current conduction area and reducing the internal resistance of the battery; at the same time, the flow guide gap 30 on the positive electrode collector 3 is used to connect the flow channel 21 on the insulating pad 2 and the battery injection hole, and the flow channel 21 is connected to the center hole 103 of the core 1. Therefore, during the battery injection process, the electrolyte flows from the position of the battery injection hole into the guide gap 30, the flow channel 21, and the center hole 103 of the core 1 in sequence, thereby entering the interior of the core 1, ensuring that the electrolyte enters the interior of the core 1 smoothly, reducing the time for the electrolyte to enter the interior of the core 1, and improving the battery injection efficiency. In addition, the multi-electrode cylindrical lithium battery of the present invention adopts a method of welding the multi-electrode 10 with the positive electrode collector 3, which does not need to be flattened, so there will be no crushed particles, and no crushed particles will enter the positive or negative terminal of the battery, causing a short circuit in the battery.

[0042] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A multi-electrode cylindrical lithium battery, comprising a winding core and a positive current collector, wherein the positive current collector is arranged at the positive end of the winding core, and an insulating pad is arranged between the winding core and the positive current collector to isolate the positive current collector from contacting the winding core, characterized in that: The positive end of the winding core is provided with a plurality of positive ears, each of the positive ears passes through the insulating pad and is welded to the positive current collector, the insulating pad is provided with a flow channel communicating with the central hole of the winding core, the positive current collector is provided with a flow guide gap penetrating through its opposite surface, and the flow guide gap connects the flow channel and the injection hole of the battery.

2. The multi-electrode cylindrical lithium battery according to claim 1, characterized in that: A plurality of positive lugs are provided on opposite sides of the positive terminal of the winding core, the plurality of positive lugs on one side of the positive terminal of the winding core are set as a first positive lug group, and the plurality of positive lugs on the other side of the positive terminal of the winding core are set as a second positive lug group, the first positive lug group and the second positive lug group are separated by the positive current collector, the surface of the positive current collector facing away from the insulating pad is divided into a first welding area and a second welding area by the guide gap, the plurality of positive lugs of the first positive lug group are welded to the first welding area, and the plurality of positive lugs of the second positive lug group are welded to the second welding area.

3. The multi-electrode cylindrical lithium battery according to claim 1 or 2, characterized in that: The guide slits are provided with two, the first ends of the two guide slits do not penetrate the first end surface of the positive electrode collector, and the second ends of the two guide slits penetrate the second end surface of the positive electrode collector, so that the positive electrode collector can be bent at the position between the two guide slits.

4. The multi-electrode cylindrical lithium battery according to claim 2, characterized in that: The number of positive electrode tabs in the first positive electrode tab group is the same as the number of positive electrode tabs in the second positive electrode tab group.

5. The multi-electrode cylindrical lithium battery according to claim 2, characterized in that: The first positive electrode tab group and the second positive electrode tab group are mirror-symmetric with respect to the positive electrode current collector.

6. The multi-electrode cylindrical lithium battery according to claim 2, characterized in that: Two opposite sides of the insulating pad are respectively provided with air-avoiding grooves for avoiding the first positive electrode tab group and the second positive electrode tab group.

7. The multi-electrode cylindrical lithium battery according to claim 2 or 6, characterized in that: A groove is formed on the surface of the insulating pad facing away from the winding core, and the positive electrode current collector is embedded in the groove.

8. The multi-electrode cylindrical lithium battery according to claim 7, characterized in that: The surface of the positive electrode current collector facing away from the insulating pad is flush with the surface of the insulating pad facing away from the winding core.

9. The multi-electrode cylindrical lithium battery according to claim 8, characterized in that: The insulating pad is also provided with a plurality of through holes penetrating the opposite surface thereof and located outside the groove.

10. The multi-electrode cylindrical lithium battery according to claim 9, characterized in that: The insulating pad is provided with a through hole at each of the four corners.

Images