Cathode collector plate assembly and multi-tab cylindrical battery

Abstract

The utility model relates to the technical field of cylindrical lithium batteries, in particular to a cathode current collecting plate assembly and a multi-lug cylindrical battery, the cathode current collecting plate assembly is used for being arranged at a cathode end of a battery roll core with a plurality of cathode lugs and comprises a current collecting piece and an insulating piece, the insulating piece is arranged between the roll core and the current collecting piece, and the cathode end of the battery roll core is provided with a plurality of cathode lugs. The current collecting piece comprises a disc body and a plurality of connecting pieces, and the connecting pieces are evenly distributed on the periphery of the disc body with the disc body as the center. The disc body protrudes out of the connecting piece, and a plurality of protruding points are arranged on the disc body. The insulating part is provided with a plurality of notches to avoid the negative tabs, and the middle part of the insulating part is provided with a through groove corresponding to the plate body; the insulating part comprises a plurality of edge parts and matching parts, the matching parts are in one-to-one correspondence with the connecting sheets, and the edge parts are arranged on the periphery of the insulating part and one sides of the matching parts; and at least one liquid injection hole is formed in the edge part. According to the utility model, the potential safety hazard of short circuit of the battery caused by dust particles generated when the tabs are kneaded is avoided.

Description

Technical Field

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

[0002] With the widespread use of lithium-ion batteries around the world, especially in high-power demand scenarios such as electric vehicles, power tools and smart home products, the requirements for battery fast charging, fast discharging and temperature rise control are becoming increasingly higher. Traditional cylindrical lithium-ion batteries use a single-pole or double-pole design, but the internal resistance of this lithium-ion battery is large, which causes the battery temperature to rise sharply during high-power charging and discharging, affecting the battery's performance and life, and can no longer meet the needs of high-power applications.

[0003] The full-ear design is a new solution proposed in recent years to solve this problem. It significantly shortens the effective path of the current by setting multiple ears on the entire surface of the positive and negative electrodes of the battery, thereby reducing the internal resistance of the battery. However, the full-ear battery also encountered some challenges during its implementation. For example, the full-ear battery requires the positive and negative ears to be flattened and welded to the current collector, which will cause the ear part to be crushed, and the crushed particles may enter the positive or negative terminal inside the battery, causing the assembled battery to short-circuit, so this solution has certain safety hazards. In addition, when the full-ear battery is filled with liquid, because the positive and negative ends are covered by the flattened positive and negative ears, it is difficult for the electrolyte to enter the inner part of the winding core during liquid filling, affecting production efficiency. Utility Model Content

[0004] The utility model provides a negative electrode current collecting disc assembly and a multi-electrode tab cylindrical battery, so as to solve the technical problem that when the negative electrode current collecting disc assembly is connected with the pole tab, the pole tab needs to be flattened, resulting in a short circuit of the assembled battery.

[0005] The utility model provides a negative electrode current collecting plate assembly, which is used to be arranged at the negative end of a battery winding core having a plurality of negative electrode ears, and comprises a current collecting plate and an insulating member, wherein the insulating member is arranged between the winding core and the current collecting plate to isolate the current collecting plate from contacting the winding core.

[0006] The current collecting sheet comprises a disc body and a plurality of connecting sheets, the connecting sheets are evenly distributed around the disc body with the disc body as the center, and the connecting sheets are arranged at an angle with each other; the disc body is arranged to protrude from the connecting sheets, and a plurality of convex points are arranged on the disc body;

[0007] The insulating member is provided with a plurality of notches to avoid the negative electrode ear and a through groove is provided in the middle thereof corresponding to the disk body; the insulating member includes a plurality of edge portions and matching portions, the matching portions are assembled one-to-one with the connecting pieces, and the edge portions are arranged on the periphery of the insulating member and on one side of the matching portions; at least one liquid injection hole is opened on the edge portion.

[0008] The convex point can ensure the contact between the current collector and the bottom of the steel shell during spot bottom welding, which improves the welding reliability and firmness of spot bottom welding. The setting of the injection hole ensures that the electrolyte can smoothly enter the inner part of the winding core without affecting the battery injection efficiency. The setting of multiple negative ears can effectively reduce the internal resistance of the battery, and the setting of the notch avoids the generation of broken particles when the ear is flattened, preventing the safety hazard of battery short circuit after assembly.

[0009] As a preferred technical solution of the utility model, two connecting pieces are provided, and the two connecting pieces are symmetrically arranged on both sides of the disc body.

[0010] As a preferred technical solution of the present utility model, the number of the edge portions is two.

[0011] As a preferred technical solution of the utility model, the insulating member is arranged in a "Z" shape as a whole, the end of the insulating member is arranged in an arc shape, the matching portion constitutes the middle part of the "Z"-shaped insulating member, and the edge portion constitutes the two ends of the "Z"-shaped insulating member.

[0012] As a preferred technical solution of the present utility model, the current collecting piece is detachably connected to the insulating member.

[0013] As a preferred technical solution of the present invention, the thickness of the edge portion is greater than the thickness of the matching portion.

[0014] As a more preferred technical solution of the present invention, the thickness of the edge portion is the sum of the thickness of the matching portion and the connecting piece.

[0015] As a preferred technical solution of the present utility model, the insulating member is a plastic member.

[0016] Another aspect of the utility model provides a multi-electrode lug cylindrical battery, comprising the above-mentioned negative electrode current collecting disc assembly and a winding core, wherein the winding core is formed by winding a pole sheet, and a plurality of negative electrode lugs are provided at the negative end of the winding core, each negative electrode lug is passed through the notch and then bent and welded to the current collecting sheet, the negative electrode lugs are distributed in the radial direction of the central hole of the winding core and are aligned, and the length of the negative electrode lugs is arranged in an increasing manner from the inner circle to the outer circle.

[0017] As a preferred technical solution of the utility model, the negative electrode ear is tilted at a certain angle to the pole piece. The negative electrode ear and the pole piece are tilted to ensure that the negative electrode ear will not block the central hole of the winding core when folded; at the same time, the tilted negative electrode ear helps to optimize the distribution of current inside the battery, avoiding excessive concentration of current at a certain point, thereby reducing local overheating and uneven current density, and improving the charging and discharging efficiency and uniformity of the battery.

[0018] As a preferred technical solution of the utility model, the angle between the negative electrode ear and the electrode piece is 15°-89°.

[0019] The beneficial effects are:

[0020] 1. The utility model provides a notch in the negative collector plate assembly to avoid the negative pole ear, thereby avoiding the generation of broken particles when the pole ear is flattened, and preventing the safety hazard of battery short circuit after assembly. The convex points on the collector plate body help to improve the contact with the negative pole ear, and the insulating member ensures the insulation between the collector plate and the winding core to prevent short circuit.

[0021] 2. The utility model has multiple negative pole ears at the negative end. The multiple ears can significantly shorten the current path and reduce the internal resistance of the battery, thereby reducing the temperature rise during high-power charging and discharging, and improving the efficiency and life of the battery. The negative pole ears are distributed in the radial direction of the center hole of the winding core and are aligned. This arrangement helps to evenly distribute the current and avoid current concentration at a few points, thereby reducing local overheating and uneven current density. Considering the spatial distribution inside the winding core and the optimization of the current path, the negative pole ears gradually increase in length from the inner circle to the outer circle. The longer negative pole ears can more effectively contact the current collector, ensuring that the current can flow evenly from the inside of the battery to the current collector. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present invention will become easy to understand. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0023] Figure 1 is a schematic structural diagram of the current collecting sheet in Example 1;

[0024] Figure 2 is a schematic structural diagram of the insulating member in Example 1;

[0025] Figure 3 Schematic diagram of the structure of the negative electrode current collecting disc assembly (the current collecting plate and the insulating member are assembled together) in Example 1;

[0026] Figure 4 It is a schematic diagram of the structure of the battery coil core;

[0027] Figure 5 It is a schematic diagram of the structure of the connection between the winding core and the negative electrode current collecting disc assembly.

[0028] Description of reference numerals:

[0029] 1. Current collector; 11. Disc; 12. Connecting piece; 13. Bump; 2. Insulating piece; 21. Notch; 22. Through groove; 23. Matching part; 24. Edge; 25. Liquid injection hole; 3. Winding core; 31. Center hole; 4. Negative electrode ear. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0031] Any number of elements in the drawings is for illustration and not limitation, and any naming is for distinction only and does not have any limiting meaning.

[0032] The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0033] like Figure 1-5 A negative electrode current collector plate assembly is shown, which is used to be arranged at the negative end of a battery winding core 3 having multiple negative electrode ears 4, and includes a current collector sheet 1 and an insulating member 2. The insulating member 2 is arranged between the winding core 3 and the current collector sheet 1 to isolate the current collector sheet 1 from contacting the winding core 3.

[0034] like Figure 1 As shown, the current collector 1 includes a disk body 11 and two connecting pieces 12, and the two connecting pieces 12 are symmetrically distributed on both sides of the disk body 11 with the disk body 11 as the center; the disk body 11 is protruding from the connecting piece 12, and the width of the connecting piece 12 is greater than the outer diameter of the disk body 11 to prevent the negative pole ear 4 from contacting the disk body 11. The connecting piece 12 is arranged in an inward arc shape on both sides near the disk body 11 (that is, the middle part of the current collector 1 is arranged in an inward arc shape). The inward arc shape can increase the contact area between the current collector 1 and the negative pole ear 4, which helps to improve the collection and distribution of current, reduce the contact resistance, thereby reducing the internal resistance of the battery and improving the electrochemical performance of the battery. A number of convex points 13 are arranged on the disk body 11. The convex points 13 can ensure the contact between the current collector 1 and the bottom of the steel shell during spot bottom welding, ensure the reliability of spot bottom welding, and increase firmness. The current collector 1 is made of nickel or nickel-copper-nickel composite material. Of course, in other embodiments, the connecting piece 12 can also be set to three, four or even more.

[0035] like Figure 2 As shown, the insulating member 2 is arranged in a "Z" shape as a whole, and the end of the insulating member 2 is arranged in an arc shape. A through groove 22 is arranged in the middle of the insulating member 2, and the through groove 22 is arranged corresponding to the disk body 11. The size and dimensions of the through groove 22 are the same as those of the disk body 11; the insulating member 2 includes a matching portion 23 and an edge portion 24. There are two matching portions 23, which are respectively located on both sides of the through groove 22. The two matching portions 23 are arranged one by one with the connecting piece 12, and the matching portion 23 constitutes the middle part of the "Z"-shaped insulating member 2; there are two edge portions 24, which are distributed at the ends of the insulating member 2, constituting the two ends of the Z"-shaped insulating member 2; the two edge portions 24 are respectively arranged on different sides of the two matching portions 23 in a centrally symmetrical manner and are located at the periphery of the matching portion 23. The edge portion 24 is provided with a liquid injection hole 25 to ensure that the electrolyte enters the interior of the winding core 3 smoothly without affecting the battery injection efficiency. The liquid injection hole 25 can be set to one or more. Two notches 21 are provided on the insulating member 2 for the negative electrode multi-pole ear to pass through and fold on the current collector 1 for welding.

[0036] In other embodiments, four edge portions 24 may also be provided, which are respectively provided on both sides of the end of the matching portion 23 .

[0037] In other embodiments, the number of the matching portions 23 may be three, four or even more, and the number of the edge portions 24 is the same as or twice the number of the matching portions 23. The number of the notches 21 is the same as that of the matching portions 23.

[0038] In other embodiments, the edge portion 24 of the insulating member 2 may be omitted, and the insulating member 2 is wrapped around the current collecting sheet 1 .

[0039] like Figure 2 and 3 As shown, the current collecting sheet 1 is detachably connected to the insulating member 2, and the thickness of the edge portion 24 is the sum of the thicknesses of the matching portion 23 and the connecting sheet 12. The insulating member 2 is made of plastic and is an insulating gasket.

[0040] Obviously, this embodiment also provides a multi-electrode cylindrical battery, including the above-mentioned negative electrode current collecting disc assembly and winding core 3:

[0041] like Figure 4 and 5 As shown, the winding core 3 is wound by the pole piece, and the negative end of the winding core 3 is provided with a plurality of negative pole ears 4, each negative pole ear 4 is passed through the notch 21 and bent and welded to the current collector 1, and the negative pole ears 4 are distributed in the radial direction of the central hole 31 of the winding core and are aligned, and the length of the negative pole ears 4 is arranged in an increasing manner from the inner circle to the outer circle. In this embodiment, two groups of negative pole ears 4 are provided, which are respectively arranged at the two notches 21 (i.e., distributed on both sides of the central hole 31). In other embodiments, the negative pole ears 4 can also be set to three groups, four groups, or more groups, and the number of negative pole ears 4 is consistent with the number of notches 21.

[0042] The angle between the negative electrode ear 4 and the electrode sheet is 45°. The negative electrode ear 4 and the electrode sheet are tilted to ensure that the negative electrode ear 4 does not block the central hole 31 of the winding core 3 when folded. Of course, in other embodiments, the angle between the negative electrode ear 4 and the electrode sheet can also be 30°, 60°, 75°, 80°, etc.

[0043] The current collecting sheet 1 is first spot-bottom welded through the center hole 31 of the winding core (the center hole 31 corresponds to the disk body 11 and the size of the disk body 11 is larger than the center hole 31), and the disk body 11 of the current collecting sheet is welded to the bottom of the steel shell to realize the negative pole conduction of the battery. The convex point 13 can ensure the contact between the current collecting sheet 1 and the bottom of the steel shell during spot bottom welding, ensure the reliability of spot bottom welding, and increase firmness.

[0044] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "upper", "middle", "angle", "thickness", "radial" and other terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings of this specification, which are only for the purpose of facilitating the explanation of the scheme of the utility model and simplifying the description, rather than explicitly or implicitly indicating that the device or element involved must have the specific orientation, be constructed and operate in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of the utility model.

[0045] In addition, in the description of this specification, “plurality” means at least two, for example, two, three or more, etc., unless otherwise clearly and specifically defined.

Claims

1. A negative electrode current collector assembly, used for being arranged at the negative end of a battery winding core (3) having a plurality of negative electrode ears (4), comprising a current collector (1) and an insulating member (2), wherein the insulating member (2) is arranged between the winding core (3) and the current collector (1) to isolate the current collector (1) from contact with the winding core (3), characterized in that: The current collecting sheet (1) comprises a disk body (11) and a plurality of connecting sheets (12); the connecting sheets (12) are evenly distributed around the disk body (11) with the disk body (11) as the center, and the connecting sheets (12) are arranged at an angle to each other; the disk body (11) is arranged to protrude from the connecting sheets (12), and the disk body (11) is provided with a plurality of protrusions (13); The insulating member (2) is provided with a plurality of notches (21) to avoid the negative electrode ear (4) and is provided with a through groove (22) in the middle thereof corresponding to the disk body (11); the insulating member (2) comprises a plurality of edge portions (24) and a matching portion (23), the matching portion (23) being assembled with the connecting piece (12) in a one-to-one correspondence, the edge portion (24) being arranged on the periphery of the insulating member (2) and on one side of the matching portion (23); and at least one injection hole (25) is provided on the edge portion (24).

2. A negative electrode current collecting disc assembly according to claim 1, characterized in that: Two connecting plates (12) are provided, and the two connecting plates (12) are symmetrically arranged on both sides of the disk body (11).

3. A negative electrode current collecting disc assembly according to claim 2, characterized in that: The number of the edge portions (24) is two.

4. A negative electrode current collecting disc assembly as claimed in claim 3, characterized in that: The insulating member (2) is arranged in a "Z" shape as a whole, the end of the insulating member (2) is arranged in an arc shape, the matching portion (23) constitutes the middle part of the "Z"-shaped insulating member (2), and the edge portion (24) constitutes the two ends of the "Z"-shaped insulating member (2).

5. A negative electrode current collecting disc assembly as claimed in claim 4, characterized in that: The current collecting piece (1) is detachably connected to the insulating member (2).

6. A negative electrode current collecting disc assembly as claimed in claim 5, characterized in that: The thickness of the edge portion (24) is the sum of the thicknesses of the matching portion (23) and the connecting piece (12).

7. A negative electrode current collecting disc assembly according to claim 6, characterized in that: The insulating part (2) is a plastic part.

8. A multi-electrode cylindrical battery, characterized in that: It comprises a negative electrode current collecting disc assembly and a winding core (3) as described in any one of claims 1 to 7, wherein the winding core (3) is wound by a pole sheet, and a plurality of negative electrode ears (4) are provided at the negative end of the winding core (3), each negative electrode ear (4) passes through the notch (21), is bent, and then welded to the current collecting sheet (1), the negative electrode ears (4) are distributed in the radial direction of the center hole (31) and are aligned, and the length of the negative electrode ears (4) is arranged in an increasing manner from the inner circle to the outer circle.

9. A multi-electrode cylindrical battery as claimed in claim 8, characterized in that: The negative electrode ear (4) is arranged at a certain angle to the electrode sheet.

10. A multi-electrode cylindrical battery as claimed in claim 9, characterized in that: The angle between the negative electrode ear (4) and the electrode sheet is 15°-89°.

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