Cathode collector plate structure of cylindrical battery and cylindrical battery

Abstract

The utility model discloses a cathode collector plate structure of a cylindrical battery and the cylindrical battery, and the cathode collector plate structure comprises a cathode collector plate body, the negative collector plate body is provided with at least two collector plate welding parts used for being welded with tabs of a battery cell, and at least two collector plate elastic sheets staggered with the collector plate welding parts; a collector plate side wing is connected to the circumferential edge of the negative collector plate body, and the lower end of the collector plate side wing is flush with or higher than the negative collector plate body. According to the scheme provided by the utility model, the collector plate welding part and the collector plate elastic sheet are arranged at an interval, the collector plate side wing is arranged on the side edge of the collector plate body and is connected with the battery shell, the joint of the collector plate side wing and the collector plate body is in arc transition, and the lower end of the side wing is flush with or slightly higher than the collector plate body; according to the scheme, the problem of potential safety hazards caused by the fact that the edge sinks and is inserted into a roll core during rolling groove sealing is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of cylindrical battery structures, in particular to a cylindrical battery negative electrode current collecting disc structure and a cylindrical battery. Background Art

[0002] When assembling cylindrical lithium-ion batteries, a current collector is usually used to connect the tabs to the battery caps. Specifically, one end of the current collector is welded to the battery tabs by laser welding, and the other end of the current collector is connected to the battery cap by welding or riveting, so that the cylindrical lithium-ion battery is sealed and a current loop is formed.

[0003] At present, in order to increase the battery capacity, it is necessary to ensure the space utilization inside the shell. The usual practice is to overlap the side wall with the bottom plane by rolling grooves. However, during the rolling groove process, the connector will bend. Since the contour of the connector at the bend is a curve, when the end welded to the side wall of the shell bends inward, the internal stress generated at the bend will cause the edge of the connector to deform and sink severely, causing the connector to be inserted into the core, which may cause lithium deposition at the least and cause safety hazards at the worst. Utility Model Content

[0004] In view of the problem pointed out in the above background technology that when rolling grooves to seal, the edge of the connector sinks and is inserted into the winding core, causing safety hazards, the purpose of the utility model is to provide a cylindrical battery negative electrode collector plate structure and a cylindrical battery.

[0005] To achieve the above purpose, the technical solution provided by the utility model is as follows:

[0006] According to one aspect of an embodiment of the utility model, a negative electrode current collector plate structure of a cylindrical battery is provided, comprising a negative electrode current collector plate body, the negative electrode current collector plate body being annular, and the middle portion thereof being a current collector plate through hole; the negative electrode current collector plate body being provided with at least two current collector plate welding portions for welding to the pole ears of a battery cell, and at least two current collector plate spring pieces staggered with the current collector plate welding portions; the circumferential edge of the negative electrode current collector plate body being connected with a current collector plate side wing connected to the battery housing, forming an arc transition at the connection with the negative electrode current collector plate body, staggered with the current collector plate welding portions and arranged at an angle with the negative electrode current collector plate body, the lower end of the current collector plate side wing being flush with or higher than the negative electrode current collector plate body.

[0007] Wherein, the angle between the negative electrode current collecting plate body and the side wing of the current collecting plate is 120°-150°.

[0008] Wherein, the lower end of the side wing of the current collecting disk is 0.1mm-0.5mm higher than the negative electrode current collecting disk body.

[0009] The bending area of ​​the wing of the collecting plate is provided with a plurality of wing through holes which pass through the bending, are arranged radially and are arranged circumferentially, and the plurality of wing through holes are arranged at intervals in the circumferential direction.

[0010] Wherein, the current collecting plate welding part is provided with a current collecting plate buffer part which is convex upward in the middle and is annular and divides the current collecting plate welding part into two areas.

[0011] Wherein, the height of the buffer portion of the collecting disk is 0.1-0.5 mm.

[0012] There are three welding parts of the current collecting plate, and correspondingly, there are three spring pieces of the current collecting plate.

[0013] Wherein, the collecting plate spring is provided with spring through holes arranged in the radial direction.

[0014] Among them, one end of the inner side of the current collecting disk spring piece is arranged at the current collecting disk through hole and connected to the current collecting disk through hole, the current collecting disk spring piece protrudes toward one side of the cover plate, and a butt portion is bent and formed on each current collecting disk spring piece, and the butt portion protrudes from the side of the negative electrode current collecting disk body away from the battery cell, the butt portion is tightly pressed against the battery cover plate, and one end of two adjacent current collecting disk spring pieces is connected by a spring piece connecting portion.

[0015] According to another aspect of the embodiments of the utility model, a cylindrical battery is provided, comprising the cylindrical battery negative electrode current collector structure as described in any one of the above items.

[0016] Compared with the prior art, the beneficial effects of the utility model are:

[0017] The solution provided by the utility model is that the welding part of the collecting disc is arranged at an interval with the collecting disc spring piece, and the collecting disc side wings are arranged on the side of the collecting disc body, the collecting disc side wings are connected to the battery housing, the connection between the collecting disc side wings and the collecting disc body is an arc transition, and the lower end of the side wing is level with the negative electrode collecting disc body or slightly higher than the collecting disc body. This solution solves the problem of safety hazards caused by the edge sinking and inserting into the winding core when the rolling groove is sealed.

[0018] In addition, the utility model is provided with a current collecting plate buffer portion. The arrangement of this structure can buffer stress concentration during welding, and can also buffer the pressure of the welding pressure head so that the side wings of the current collecting plate are in close contact with the shell, and the side wings of the current collecting plate have a buffering effect.

[0019] In addition, the utility model connects the collector plate springs by arranging a spring-piece connecting portion. When the battery cell expands due to thermal runaway, the pressure generated by the battery cell or the pressure inside the buffer cavity can squeeze the negative collector plate body, so that the spring-piece connecting portion on the negative collector plate body breaks. After the spring-piece connecting portion breaks, the bent collector plate spring can deform to absorb the pressure generated by the expansion of the battery cell, so that the expansion pressure of the battery cell can be fully released; by arranging spring-piece through holes on the collector plate springs, the arrangement of the through holes can further increase the exhaust channel of the battery cell, so that the battery cell can be better exhausted when the core is rolled. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present disclosure 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 disclosure. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0021] Figure 1 This is a first schematic diagram of the structure of Embodiment 1 of the present application;

[0022] Figure 2 This is a second schematic diagram of the structure of Embodiment 1 of the present application;

[0023] Figure 3 This is a third schematic diagram of the structure of Embodiment 1 of the present application;

[0024] Figure 4 This is a first schematic diagram of the structure of Embodiment 2 of the present application;

[0025] Figure 5 This is a second schematic diagram of the structure of Embodiment 2 of the present application;

[0026] Figure 6 This is a first schematic diagram of the structure of Embodiment 3 of the present application;

[0027] Figure 7 This is a second schematic diagram of the structure of Embodiment 3 of the present application;

[0028] Figure 8 This is a schematic diagram of the partial structure of Example 3 of the present application;

[0029] Fig. 9 for Figure 8 A schematic diagram of the structure of the first amplifying part;

[0030] Fig.10 for Figure 8 A schematic diagram of the structure of the second amplifying part;

[0031] In the figure, a current collector welding portion 1, a current collector through hole 2, a negative current collector body 3, a current collector side wing 4, a side wing edge 41, a lower tied edge 42, a side wing through hole 5, a spring connecting portion 6, a current collector spring 7, a spring through hole 8, a current collector buffer portion 9, a welding pressure head 10, a negative current collector 11, a battery housing 12, a battery cell 13, a positive electrode column 14, a positive current collector 15, D is a first enlargement portion, E is a second enlargement portion, and a negative electrode ear 16. DETAILED DESCRIPTION

[0032] 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. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0035] The utility model provides a negative collector plate structure for a cylindrical battery, including a collector plate welding part, a collector plate connecting part, a collector plate spring piece, a collector plate through hole, a collector plate wing, a negative collector plate buffer part, etc. Among them, the negative collector plate body is annular, and at least two collector plate welding parts are arranged on it, which are used for welding with the pole ears of the battery core. The collector plate welding part and the collector plate spring piece are arranged at intervals. The collector plate wing is arranged on the side of the negative collector plate body, and the collector plate wing is connected to the battery shell. The connection between the collector plate wing and the negative collector plate body is an arc transition, and the lower end of the collector plate wing is level with or slightly higher than the negative collector plate body. The use of the present application scheme can solve the problem of potential safety hazards caused by the edge of the connector sinking and inserting into the winding core when rolling the groove to seal. The setting of the negative collector plate buffer part can not only buffer the stress concentration during welding, but also buffer the pressure of the welding pressure head so that the collector plate wing is in close contact with the shell.

[0036] Example 1

[0037] like Figure 1-Figure 3 As shown, this embodiment provides a negative electrode current collector structure of a cylindrical battery, including a negative electrode current collector body 3, which is annular, and the middle part of which is a current collector through hole 2; the negative electrode current collector body 3 is provided with at least two current collector welding parts 1 for welding to the pole ears of the battery cell, and at least two current collector springs 7 staggered with the current collector welding parts 1; the circumferential edge of the negative electrode current collector body 3 is connected with a current collector side wing 4 which is connected to the battery housing 12, has an arc transition at the connection with the negative electrode current collector body 3, is staggered with the current collector welding part 1 and is arranged at an angle with the negative electrode current collector body 3, and the lower end of the current collector side wing 4 is level with or higher than the negative electrode current collector body 3.

[0038] In a preferred embodiment, there are three collector plate welding parts 1, and correspondingly, there are three collector plate spring pieces 7. The three collector plate side wings are evenly spaced along the circumference of the negative electrode collector plate body, and the height of each collector plate side wing is 10mm-20mm, and the width is 4mm-8mm. Of course, there may be 4, 5, etc. collector plate welding parts 1, and correspondingly, there may be 4, 5, etc. collector plate spring pieces 7. The collector plate welding parts 1 and the collector plate side wings 4 are staggered, that is, the collector plate side wings 4 are not connected to the collector plate welding parts 1. Such an arrangement can prevent the heat effects of the two welds from interfering, otherwise interference will occur and cause another poor weld. Preferably, the center of the collector plate welding part and the center of the collector plate side wing are staggered at an angle of 60°.

[0039] It should be noted that the collecting plate side wing 4 is welded to the battery shell 12, and a necking structure is provided on the battery shell 12. The collecting plate side wing 4 is located below the necking. By providing the collecting plate side wing 4, the strength of the negative electrode collecting plate body 3 can be improved, and the reliability of the electrical connection between the negative electrode collecting plate 11 and the battery shell 12 can be ensured, thereby avoiding deformation of the negative electrode collecting plate 11 during the necking process, thereby avoiding deformation of the negative electrode collecting plate 11 at this stage to squeeze the battery cell 13 or insert into the battery cell 13, causing the battery cell to fail in a short circuit.

[0040] It should be noted that the collector disc wing 4 can be bent relative to the negative collector disc body 3 so that the collector disc wing 4 can be set at an angle with the negative collector disc body 3, and a wing through hole 5 is provided on the boundary line with the negative collector disc body. The bending area of ​​the collector disc wing 4 is provided with a plurality of wing through holes 5 that pass through the bend, are arranged radially, and are arranged circumferentially, and the plurality of wing through holes 5 are arranged at intervals in the circumferential direction. The negative collector disc welding portion is used to connect the winding core ear, and the collector disc wing 4 is used to connect the battery shell. When the shell begins to roll the groove to seal, the collector disc wing 4 begins to rotate relative to the negative collector disc body along with the shell. The side wing through hole 5 opened on the bend reduces the strength of the bend. The internal stress generated in the process of the collecting plate side wing 4 rotating inward toward the negative collector plate body is relatively small, and the generated internal stress can be released through the deformation of the side wing through hole 5, which greatly reduces the degree of sinking of the edge of the collecting plate side wing 4, prevents the edge of the collecting plate side wing 4 from being inserted into the winding core when the rolling groove is sealed, and reduces safety hazards.

[0041] In a preferred embodiment, the collector disc wing 4 includes a wing edge 41 facing one side of the cover plate and a lower tie edge 42 facing the battery cell and abutting the battery cell. The collector disc wing 4 is connected to the circumferential edge of the negative electrode collector disc body 3 and can rotate relative to the main body so that the collector disc wing 4 is tilted and arranged at an angle with the negative electrode collector disc body 3, and the angle is 100°-150°. Such an arrangement can make the collector disc wing 4 have a buffering effect, prevent the edge from sinking and inserting into the winding core when rolling the groove to seal, reduce safety hazards, and improve safety. Among them, the angle can be 100°, 110°, 120°, 130°, 140°, 150°. If the angle is too small, the collector disc wing 4 has less contact with the battery housing 12, and it is easy to cause cold welding; if the angle is too large, the gap between the collector disc wing 4 and the battery housing 12 is too large, and the two are not easy to clamp, resulting in poor welding.

[0042] In a preferred embodiment, at least two current collecting disc springs 7 are arranged on the negative electrode current collecting disc body 3, and the current collecting disc springs 7 are arranged at intervals from the current collecting disc welding part 1. A buttress portion is bent and formed on each current collecting disc spring 7, and the buttress portion protrudes from the side of the negative electrode current collecting disc body 3 away from the battery cell 13. The buttress portion is tightly pressed against the cover plate of the battery, and one end of two adjacent current collecting disc springs 7 is connected by a spring connecting portion 6. The negative electrode current collector 11 is arranged in the battery housing 12, and the negative electrode current collector 11 is located on one side of the battery cell 13. One side of the current collector welding part 1 is pressed against the battery cell 13, and the current collector side wing 4 is pressed against the inner wall of the end of the battery housing 12, so that a buffer cavity is formed between the battery cell 13 and the battery housing 12. The current collector spring 7 is connected by setting the spring connection part 6. When the battery cell 13 undergoes thermal runaway expansion, the pressure generated by the battery cell 13 or the pressure inside the buffer cavity can squeeze the negative electrode current collector 11, so that the spring connection part 6 on the negative electrode current collector 11 breaks. After the spring connection part 6 breaks, the bent current collector spring 7 can generate deformation to absorb the pressure generated by the expansion of the battery cell 13, so that the expansion pressure of the battery cell 13 can be fully released. By setting the current collector spring 7, when the battery is charged and discharged to generate gas, the current collector spring 7 is connected to the battery cover, so that the battery cover is also charged and will not rust during long-term use. In addition, the collecting plate spring 7 is provided with a spring through hole 8, and the provision of the spring through hole 8 can further increase the exhaust channel of the battery cell 13, so that the battery cell 13 can be better exhausted when the core is rolled.

[0043] In a preferred embodiment, the spacing distance between the collector plate welding part 1 and the collector plate shrapnel 7 is 0.2mm-1.0mm, and the collector plate welding part 1 is a fan ring with an inner diameter of 8mm-16mm. When the battery cell 13 is in a thermal runaway state, it is ensured that the battery cell 13 has enough space to pull out the core. The outer diameter of the collector plate welding part 1 is 35mm-41mm, and a gap of 0.2mm-1.0mm is maintained between it and the outer ring of the negative electrode collector plate body 3. When the battery cell 13 is in a thermal runaway state, it can move with the pole ear of the battery cell 13 to prevent the gas generated by the battery cell from being unable to escape smoothly, resulting in the battery cell explosion.

[0044] In a preferred embodiment, the diameter of the negative electrode current collector plate body 3 is 36mm-42mm, the thickness is 0.2mm-0.6mm, and the width of the current collector plate spring piece 7 is 0.2-0.6mm. By limiting the thickness of the negative electrode current collector plate body 3, the strength of the negative electrode current collector plate body 3 can be ensured, and the connection stability between the negative electrode current collector plate and the battery shell can be ensured; by limiting the width of the negative electrode current collector plate, the strength can be ensured. When the battery cell expands normally, the current collector plate spring piece 7 will not break. When the battery cell 13 undergoes thermal runaway expansion, it is ensured that the current collector plate spring piece 7 can be squeezed and broken by the pressure generated by the expansion of the battery cell or the pressure inside the buffer cavity.

[0045] In a preferred embodiment, the lower end of the current collecting disc wing 4 is 0.1 mm-0.5 mm higher than the negative electrode current collecting disc body.

[0046] It should be noted that the connection between the collector disc wing 4 and the negative collector disc body 3 is in an arc transition, and the lower end of the collector disc wing 4 is flush with the negative collector disc body 3 or slightly higher than the negative collector disc by 0.1-0.5mm. This arrangement can make the collector disc wing have a buffering effect, preventing the edge from sinking and inserting into the winding core when rolling the groove to seal, reducing safety hazards and improving safety.

[0047] In addition, the folded collecting plate side wings 4 have a certain elasticity, and the collecting plate springs are tightly pressed against the cover plate of the battery, which can reduce the space occupied by the collecting plate, thereby reducing the size of the battery.

[0048] Example 2

[0049] like Figure 4-6 FIG. 2 is another embodiment of the present application. In this embodiment, a current collecting plate buffer portion 9 is provided on the current collecting plate welding portion 1. The current collecting plate buffer portion 9 is annular and convex in the middle and divides the current collecting plate welding portion 1 into two areas.

[0050] It should be noted that the current collecting disc buffer portion 9 is convex at the upper end and hollow at the lower end. When the welding ram 10 presses the current collecting disc buffer portion 9, the negative current collecting disc expands to both sides due to the buffering effect of the current collecting disc buffer portion 9, so that the current collecting disc side wings 4 and the battery housing 12 can be better fitted. The current collecting disc buffer portion 9 can divide the current collecting disc welding portion 1 into two areas, and perform intermittent welding to avoid the accumulation of heat generated by continuous welding, which may cause the current collecting disc to deform and affect the subsequent welding process. Among them, the height of the current collecting disc buffer portion 9 is 0.1-0.5mm.

[0051] Example 3

[0052] like Figure 6-10 The structure of the embodiment of the present application is shown.

[0053] The present embodiment provides a cylindrical battery, comprising the above-mentioned cylindrical battery negative electrode current collecting plate structure.

[0054] It should be noted that the assembly process of the cylindrical battery is as follows: the negative collector plate 11 is connected to the negative ear 16 of the battery cell by laser welding, and welding tracks are set on both the inner and outer sides of the blocking part, which can not only enhance the connection strength, but also make the welding track intermittent and prevent heat accumulation, thereby avoiding the accumulation of heat generated by continuous welding and causing the collector plate to deform, affecting the subsequent welding process. After that, the battery housing and the collector plate flank are welded, and the welding pressure head 10 presses down on the collector plate buffer part 9. Due to the buffering effect of the collector plate buffer part 9, the negative collector plate 11 expands to both sides, so that the collector plate flank 4 and the battery housing 12 can be better fitted. This arrangement can make the negative collector plate 11 and the battery housing 12 welded tightly, solving the problem of cold welding.

[0055] It should be noted that the cylindrical battery further includes a positive electrode column 14 and a positive electrode current collecting disk 15 .

[0056] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A negative electrode current collector structure for a cylindrical battery, characterized in that: The invention comprises a negative electrode current collector disc body (3), the negative electrode current collector disc body (3) is annular, and the middle part thereof is a current collector disc through hole (2); the negative electrode current collector disc body (3) is provided with at least two current collector disc welding parts (1) for welding with the pole ears of the battery cell, and at least two current collector disc springs (7) arranged alternately with the current collector disc welding parts (1); the circumferential edge of the negative electrode current collector disc body (3) is connected with a current collector disc side wing (4) which is connected with the battery housing (12), has an arc transition at the connection with the negative electrode current collector disc body (3), is arranged alternately with the current collector disc welding parts (1), and is arranged at an angle with the negative electrode current collector disc body (3); the lower end of the current collector disc side wing (4) is flush with or higher than the negative electrode current collector disc body (3).

2. A cylindrical battery negative electrode current collector structure according to claim 1, characterized in that: The included angle between the negative electrode current collecting disc body (3) and the current collecting disc wing (4) is 120°-150°.

3. A cylindrical battery negative electrode current collector structure according to claim 1, characterized in that: The lower end of the current collecting disc wing (4) is 0.1 mm to 0.5 mm higher than the negative electrode current collecting disc body (3).

4. A cylindrical battery negative electrode current collector structure according to claim 1, characterized in that: The bent area of ​​the collecting plate side wing (4) is provided with a plurality of side wing through holes (5) which pass through the bend, are arranged radially, and are arranged circumferentially, and the plurality of side wing through holes (5) are arranged at intervals in the circumferential direction.

5. The negative electrode current collector structure of a cylindrical battery according to claim 1, characterized in that: The current collecting plate welding portion (1) is provided with a current collecting plate buffer portion (9) which is convex in the middle and annular and divides the current collecting plate welding portion (1) into two areas.

6. A cylindrical battery negative electrode current collector structure according to claim 5, characterized in that: The height of the current collecting disk buffer portion (9) is 0.1-0.5 mm.

7. The negative electrode current collector structure of a cylindrical battery according to claim 1, characterized in that: The number of the current collecting plate welding parts (1) is three, and correspondingly, the number of the current collecting plate spring pieces (7) is three.

8. The negative electrode current collector structure of a cylindrical battery according to claim 1, characterized in that: The collecting plate spring piece (7) is provided with a spring piece through hole (8) arranged in the radial direction.

9. The negative electrode current collector structure of a cylindrical battery according to claim 1, characterized in that: One inner end of the current collecting disk spring piece (7) is arranged at the current collecting disk through hole (2) and connected to the current collecting disk through hole (2); the current collecting disk spring piece (7) protrudes toward one side of the cover plate; each current collecting disk spring piece (7) is bent to form an abutment portion, the abutment portion protrudes from the side of the negative electrode current collecting disk body (3) away from the battery cell; the abutment portion is tightly abutted against the battery cover plate; one end of two adjacent current collecting disk spring pieces (7) is connected via a spring piece connecting portion (6).

10. A cylindrical battery, characterized in that: It comprises a cylindrical battery negative electrode current collector structure as described in any one of claims 1 to 9.

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