Cylindrical battery, battery pack and electronic device

Abstract

The utility model provides a cylindrical battery, battery pack and electronic device, the cylindrical battery includes: shell, electrode subassembly and current collecting member, shell includes the side wall that has the opening, the side wall includes the rolling groove, the rolling groove includes the first groove wall that deviates from the opening side; the electrode assembly is arranged in the shell, and one side, facing the opening, of the electrode assembly comprises a first tab; the current collecting component is at least partially arranged between the first tab and the rolling groove; the current collecting component comprises a current collecting body and a connecting piece, the current collecting body is electrically connected with the first tab, and the connecting piece is bent towards the axis of the shell and is welded with the first groove wall to form a welding mark; in the radial direction of the collector body, the distance between one side, close to the center of the collector body, of the welding mark and the free end of the connecting piece is A, the unfolding size of the connecting piece is B, and the distance A is smaller than or equal to 1 / 3 of the size B. According to the utility model, the technical problem that in the production process of the cylindrical battery, the current collecting component is easy to break when being bent, so that the tabs are crushed can be solved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a cylindrical battery, battery pack, and electronic device. Background Technology

[0002] In existing cylindrical batteries, a current collector is typically placed near the opening of the casing. One end of the current collector is welded to the side wall of the casing, and the other end is electrically connected to the tab of the electrode assembly, thus achieving electrical connection between the casing and the electrode assembly. However, during subsequent assembly, the casing undergoes processes such as grooving and sealing at the opening, which can easily damage the welded position between the current collector and the casing. This can lead to breakage of the current collector at the welded position with the side wall. The edges of the broken current collector can then damage the nearby tabs, affecting the conductivity and safety performance of the cylindrical battery. Utility Model Content

[0003] This utility model provides a cylindrical battery, a battery pack, and an electronic device to improve the technical problem that the current collector is prone to breakage when bent during the production process of cylindrical batteries, which leads to damage to the tabs.

[0004] To achieve the above and other related objectives, this utility model provides a cylindrical battery, which includes: a housing, an electrode assembly, and a current collector. The housing includes a sidewall with an opening, and the sidewall includes a groove recessed into the housing near the opening. The groove includes a first groove wall facing away from the opening. The electrode assembly is disposed within the housing, and the electrode assembly includes a first tab facing the opening. The groove restricts the displacement of the electrode assembly in the axial direction of the housing. The current collector is at least partially disposed between the first tab and the groove. The current collector includes a current collector body and a connecting piece connected to the periphery of the current collector body. The current collector body is electrically connected to the first tab. The connecting piece is bent towards the axis of the housing and welded to the first groove wall to form a weld mark. In the radial direction of the current collector body, the distance from the free end of the connecting piece to the side of the weld mark near the center of the current collector body is A, the unfolded dimension of the connecting piece is B, and the distance from A is less than or equal to 1 / 3 of the dimension B.

[0005] In one example of the cylindrical battery of this utility model, the distance A ranges from 0.2 to 1.0 mm.

[0006] In one example of the cylindrical battery of this utility model, along the radial direction of the cylindrical battery, the distance from the point on the groove closest to the axis of the shell to the outer peripheral surface of the shell is i, and the distance from the solder mark to the outer peripheral surface of the shell is j, where j≤0.5i.

[0007] In one example of the cylindrical battery of this utility model, the connecting piece includes a first connecting portion and a second connecting portion that are connected to each other. The portion located between the solder mark and the current collector body is the first connecting portion. The second connecting portion extends from the end of the first connecting portion near the solder mark toward the axis of the casing. The first connecting portion is bent relative to the second connecting portion to form a first bent portion. The first bent portion includes a first weak structure.

[0008] In one example of the cylindrical battery of this utility model, the first weak structure includes a first thinning region.

[0009] In one example of the cylindrical battery of this utility model, the first connecting portion is bent toward the center of the current collector body to form a second bending portion, and the second bending portion includes a second weak structure.

[0010] In one example of the cylindrical battery of this utility model, the second weak structure includes a second thinning region.

[0011] In one example of the cylindrical battery of this utility model, the thickness of the connecting piece is less than the thickness of the current collector body.

[0012] This utility model also provides a battery pack, which includes the cylindrical battery in any of the above examples.

[0013] This invention also provides an electronic device that includes the aforementioned battery pack.

[0014] In this cylindrical battery, along the radial direction of the current collector body, the distance from the free end of the connecting piece to the side of the solder mark closest to the center of the current collector body is set to A, and the unfolded dimension of the connecting piece is B. The distance A is less than or equal to 1 / 3 of dimension B. This setting limits the distance between the solder mark and the free end of the connecting piece within a suitable range by restricting the relative size of distance A and dimension B. This ensures that the bending moment generated by the grooving force on the solder mark is small during the grooving process, reducing the probability of the connecting piece breaking at the solder mark location. This reduces the probability of the edge of the current collector component damaging the nearby first electrode tab after breakage, thereby improving the conductivity and safety performance of the cylindrical battery. Simultaneously, the smaller bending moment generated by the grooving force on the solder mark also reduces the deformation stress transmitted from the solder mark location to the periphery of the current collector body during the grooving process. This reduces the downward pressure exerted by the periphery of the current collector body on the nearby first electrode tab, further reducing the risk of the current collector component damaging the electrode tab. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure in which the connecting piece bends and breaks during the sidewall grooving process in the production of existing cylindrical batteries.

[0017] Figure 2 This is a cross-sectional view of the overall structure of an example of a cylindrical battery of this utility model;

[0018] Figure 3 for Figure 2 A magnified view of a section at point A in the middle;

[0019] Figure 4 This is a partially enlarged view of the welding structure between the current collector and the sidewall in an example of the cylindrical battery of this utility model;

[0020] Figure 5 This is a schematic diagram of the electrode assembly structure of an example cylindrical battery of this utility model;

[0021] Figure 6 This is a schematic diagram showing the welding position between the grooved connecting piece and the side wall in an embodiment of the cylindrical battery of this utility model;

[0022] Figure 7 This is a partial enlarged view of the setting position of the cylindrical battery of this utility model, which is soldered on the first groove wall;

[0023] Figure 8 This is a diagram showing the results of the first set of simulation experiments in an example of the cylindrical battery of this utility model;

[0024] Figure 9 This is a simulation experiment result diagram of the second group in an example of the cylindrical battery of this utility model;

[0025] Figure 10 This is a partial structural diagram of a cylindrical battery according to the present invention, showing that the connecting piece has a thinning zone at both the first and second bends.

[0026] Figure 11 This is a partial structural diagram of a connecting piece with a thinning zone at the second bend in an example of a cylindrical battery of this utility model.

[0027] Figure 12 This is a partial structural diagram showing the overall thickness reduction of the connecting piece in an example of the cylindrical battery of this utility model.

[0028] Figure 13 This is a schematic diagram of an example of the battery pack of this utility model;

[0029] Figure 14 This is a schematic diagram of an example of the electronic device of this utility model.

[0030] Component designation explanation

[0031] 1. Electronic device; 10. Battery pack; 11. Working part; 101. Housing; 102. Housing cover; 100. Cylindrical battery; 110. Casing; 111. Side wall; 112. Opening; 113. Groove; 1131. First groove wall; 114. End wall; 115. Extension; 116. Connecting part; 120. Electrode assembly; 121. Positive electrode; 1211. Positive current collector; 1212. First coated area; 1213. First uncoated area; 122. Separator; 123. Negative electrode; 1231. Negative current collector 1232, Second coated area; 1233, Second uncoated area; 124, First tab; 125, Second tab; 130, Collector component; 131, Collector body; 132, Connecting piece; 1321, First connecting part; 1322, Second connecting part; 1323, First bending part; 1324, Second bending part; 1325, First weak structure; 1326, First thinning area; 1327, Second weak structure; 1328, Second thinning area; 140, Weld mark; 150, End cap; 160, Sealing ring. Detailed Implementation

[0032] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terminology used in the embodiments of this utility model is for describing specific implementation schemes and not for limiting the scope of protection of this utility model. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0033] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention.

[0034] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0035] Currently, during the production of the cylindrical battery 100, after the current collector 130 is welded to the side wall 111 of the casing 110, the side wall 111 undergoes processes such as grooving 113 and sealing to seal the end cap 150 at the opening 112 of the casing 110. During the grooving process, the current collector 130 inevitably bends. Due to limitations in the installation method and position between the connecting piece 132 and the side wall 111, the connecting piece 132 typically develops two bending points during grooving. The first bending point occurs near the connection between the connecting piece 132 and the current collector body 131, and the second bending point occurs in a weak area of ​​the connecting piece 132, usually near the solder mark 140, i.e., the welding position between the connecting piece 132 and the side wall 111. During grooving, when the grooving pressure is too high, the connecting piece 132 will first crack at the weakest point (i.e., near the solder mark 140), and in severe cases, it may break. The broken current collector 130 edge will spring back towards the side closer to the electrode under the stress release, thus causing pressure damage to the electrode (e.g., Figure 1 As shown in the figure, this affects the internal conductivity and safety performance of the cylindrical battery 100. Therefore, this invention provides a cylindrical battery 100, a battery pack 10, and an electronic device 1 to improve the aforementioned technical problems.

[0036] Please see Figures 2 to 14 This utility model provides a cylindrical battery 100, a battery pack 10, and an electronic device 1. By limiting the setting position of the solder mark 140 on the connecting piece 132, the cylindrical battery 100 can reduce the probability that the connecting piece 132 is prone to breakage at the position of the solder mark 140 during the grooving process of the side wall 111. This can reduce the probability that the edge of the current collector 130 will cause pressure damage to the nearby electrode after breakage, thereby improving the conductivity and safety performance of the cylindrical battery 100.

[0037] Please see Figure 2 and Figure 3 The cylindrical battery 100 provided by this utility model includes: a housing 110, an electrode assembly 120, and a current collector 130.

[0038] Please see Figure 2 The housing 110 includes an end wall 114 and a side wall 111 surrounding the end wall 114. As long as a stable sealing and electrical connection can be formed, the connection between the end wall 114 and the side wall 111 can be achieved in various ways, such as integral stamping, integral casting, or separate welding. The side wall 111 is cylindrical and surrounds the outer edge of the end wall 114, with a circular opening 112 formed at the end of the side wall 111 facing away from the end wall 114. A receiving cavity is formed within the housing 110 formed by the end wall 114 and the side wall 111 to accommodate the electrode assembly 120, electrolyte, and other necessary components of the cylindrical battery 100. Specifically, the diameter of the housing 110 can be determined according to the specific dimensions of the electrode assembly 120, such as 18mm, 21mm, or 46mm. The shell 110 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. In order to prevent the shell 110 from rusting during long-term use, a layer of anti-rust material such as metallic nickel can be plated on the surface of the shell 110.

[0039] Please continue reading. Figures 2 to 4 In one example of the cylindrical battery 100 of this utility model, the casing 110 is a cylindrical structure. The casing 110 includes an end wall 114 and a side wall 111 surrounding the end wall 114. That is, the casing 110 includes a closed end and an open end. The end wall 114 is the closed end, and the opening 112 opposite to the end wall 114 is the open end. A groove 113 is formed on the side wall 111 facing the opening 112, which is recessed into the interior of the casing 110. The groove 113 is a recessed structure formed by the side wall 111 being squeezed and deformed into the interior of the casing 110 under the action of mechanical external force. The groove 113 can be formed by stamping the side wall 111 with a forming die, or it can be formed by rolling the side wall 111 with a groove 113 cutter, as long as the groove 113 on the side wall 111 is a recessed structure arranged in the circumferential direction of the side wall 111. The cross-sectional shape of the groove 113 can be any shape that meets the usage requirements, such as rectangular, square, or trapezoidal. The sidewall 111 also has an extension 115 extending towards the center of the opening 112 on the side of the groove 113 near the opening 112. A connecting portion 116 is also provided between the extension 115 and the groove 113, and the extension 115 and the groove 113 are connected by the connecting portion 116. It should be noted that the specific dimensions of the groove 113, the extension 115, and the connecting portion 116 need to be determined according to the specific size specifications of the cylindrical battery 100. In this embodiment, no specific limitation is made. The side of the groove 113 facing away from the opening 112 has a first groove wall 1131.

[0040] Please see Figure 2 and Figure 5 The electrode assembly 120 is disposed inside the housing 110 and is a component in the cylindrical battery 100 where electrochemical reactions occur. The housing 110 may contain one or more electrode assemblies 120. The electrode assembly 120 includes an electrode sheet and a separator 122, which are wound to form a wound structure. Specifically, in this embodiment, the electrode assembly 120 includes a positive electrode sheet 121, a separator 122, and a negative electrode sheet 123 wound axially around the housing 110.

[0041] Please see Figure 5 The positive electrode 121 includes a positive current collector 1211 and a positive active material layer coated on the positive current collector 1211. A first coated area 1212 coated with the positive active material layer and a first uncoated area 1213 uncoated with the positive active material layer are formed on the positive current collector 1211. The first coated area 1212 and the first uncoated area 1213 are arranged along the axial direction of the housing 110. The first uncoated area 1213 extends to one end of the cylindrical battery 100 in the height direction to the outside of the separator 122 and is bent towards the axis of the housing 110 to form a stacked positive electrode tab.

[0042] Please continue reading. Figure 5 The negative electrode 123 includes a negative current collector 1231 and a negative active material layer coated on the negative current collector 1231. A second coated area 1232 coated with the negative active material layer and a second uncoated area 1233 uncoated with the negative active material layer are formed on the negative current collector 1231. The second coated area 1232 and the second uncoated area 1233 are arranged along the axial direction of the housing 110. The second uncoated area 1233 extends to the other end of the cylindrical battery 100 in the height direction to the outside of the separator 122 and is bent towards the axis of the housing 110 to form a stacked negative electrode tab.

[0043] Please continue reading. Figure 5A separator 122 is disposed between the positive electrode 121 and the negative electrode 123 to isolate the positive and negative active material layers. Taking a lithium-ion cylindrical battery 100 as an example, the positive current collector 1211 can be made of aluminum, and the positive active material layer includes positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative current collector 1231 can be made of copper, and the negative active material layer includes negative active material, which can be carbon or silicon, etc. The substrate material of the separator 122 can be polypropylene (PP) or polyethylene (PE), etc. To protect and insulate the electrode assembly 120, an insulating film can also be wrapped around the electrode assembly 120. The insulating film can be synthesized from PP, PE, polyethylene terephthalate (PET), polyvinyl chloride (PVC), or other polymer materials.

[0044] Please see Figure 2 and Figure 3 In one example of the cylindrical battery 100 of this utility model, the electrode assembly 120 is sealed and installed inside the housing 110. Along the height direction of the cylindrical battery 100, the electrode assembly 120 is disposed between the end wall 114 and the groove 113, and the groove 113 restricts the axial movement of the electrode assembly 120 between the end wall 114 and the groove 113. The electrode assembly 120 has a first tab 124 and a second tab 125 respectively at both ends in the height direction of the cylindrical battery 100, and the first tab 124 and the second tab 125 have opposite polarities. The first tab 124 faces the opening 112 and is the negative tab. It should be noted that in other embodiments, the first tab 124 can also be the positive tab, and the second tab 125 can be the negative tab.

[0045] Please see Figure 3 and Figure 4The cylindrical battery 100 also includes an end cap 150, which is disposed at the opening 112. The outer periphery of the end cap 150 is engaged between the extension 115, the connecting portion 116, and the groove 113 by a sealing ring 160, thereby achieving a sealed and fixed connection of the end cap 150 at the opening 112. A current collector 130 is disposed within the housing 110, located between the end cap 150 and the electrode assembly 120, and the current collector 130 is at least partially located between the first tab 124 and the groove 113. The current collector 130 includes a current collector body 131 and a connecting piece 132 connected to the periphery of the current collector body 131. The connection method between the connecting piece 132 and the current collector body 131 can be selected in various ways, such as welding connection or integral molding connection, or any connection method that can achieve electrical connection between the connecting piece 132 and the current collector body 131. In this embodiment, in order to improve assembly efficiency, the connecting piece 132 and the current collector body 131 are integrally stamped parts. The current collector 131 is electrically connected to the first tab 124 to achieve an electrical connection between the current collector 131 and the electrode assembly 120. Various electrical connection methods can be selected, such as welding, conductive adhesive bonding, or any method that enables an electrical connection between the connecting piece 132 and the first tab 124. In this embodiment, the current collector 131 and the first tab 124 are welded together. It should be noted that the connecting piece 132 being located at the periphery of the current collector 131 means that the connecting piece 132 is connected to the outer edge of the current collector 131 along the radial direction of the current collector 131.

[0046] Please see Figure 3 Along the height direction of the cylindrical battery 100, the connecting piece 132 is at least partially located between the first groove wall 1131 and the electrode assembly 120. The number of connecting pieces 132 is not limited; there can be one or more. The specific shape and size of the connecting pieces 132 are also not limited, as long as they meet the welding strength and current-conducting area requirements between the connecting piece 132 and the housing 110. Preferably, in one example of the cylindrical battery 100 of this utility model, the current-collecting member 130 includes multiple connecting pieces 132, which are arranged around the outer periphery of the current-collecting body 131. The multiple connecting pieces 132 can have the same structure or different structures, as long as they meet the current-conducting requirements and welding strength requirements between the current-collecting member 130 and the housing 110. To facilitate the positioning and connection between the connecting pieces 132 and the current-collecting member 130, in this embodiment, the multiple connecting pieces 132 have the same shape and are arranged in an array along the circumferential direction of the current-collecting body 131. This configuration allows for a more uniform flow guidance effect in the circumferential direction between the current collector 130 and the side wall 111, thereby improving the stability of the flow guidance between the housing 110 and the electrode assembly 120.

[0047] Specifically, please refer to Figure 3 , Figure 4 and Figure 6 The connecting piece 132 is located on the side of the current collector body 131 opposite to the electrode assembly 120. One end of the connecting piece 132 is connected to the periphery of the current collector body 131, and the other end of the connecting piece 132 is bent toward the axis of the housing 110 and at least partially welded to the first groove wall 1131 to form a solder mark 140, thereby realizing the electrical connection between the connecting piece 132 and the side wall 111. The specific shape of the bent connecting piece 132 is not limited; for example, the bent connecting piece 132 can be approximately U-shaped, approximately triangular, etc. Along the radial direction of the current collector body 131, the distance from the free end of the connecting piece 132 to the side of the solder mark 140 near the center of the current collector body 131 is A, and the unfolded dimension of the connecting piece 132 is B (e.g., ...). Figure 6 As shown), and the distance A is less than or equal to 1 / 3 of the dimension B. It should be noted that since the grooving 113 process is performed on the side wall 111 only after the connecting piece 132 is welded to the side wall 111, the distance A remains unchanged before and after grooving 113. Figure 4 and Figure 6 As shown. The unfolded dimension B of the connecting piece 132, that is, the dimension of the connecting piece 132 from the end connected to the periphery of the collector body 131 to its free end before bending, is as follows. Figure 6 As shown.

[0048] Considering the grooving process of sidewall 111, under the condition that the unfolded dimension B of connecting piece 132 and the position of grooving 113 of sidewall 111 are fixed, the larger the distance A between the weld mark 140 and the free end of connecting piece 132, the larger the distance between the grooving position and the weld mark 140. During the grooving process, the lever arm of the grooving force relative to the weld mark 140 is larger, resulting in a larger bending moment at the weld mark 140 position, making the weld mark 140 position more prone to breakage. Conversely, the smaller the distance A between the weld mark 140 and the free end of connecting piece 132, the smaller the distance between the grooving position and the weld mark 140. During the grooving process, the lever arm of the grooving force relative to the weld mark 140 is smaller, resulting in a smaller bending moment at the weld mark 140 position, making the weld mark 140 position less prone to breakage. Therefore, in the cylindrical battery 100 of this utility model, along the radial direction of the current collector body 131, the distance between the solder mark 140 and the center of the current collector body 131 and the free end of the connecting piece 132 is set to A, and the unfolded dimension of the connecting piece 132 is B. The distance A is less than or equal to 1 / 3 of the dimension B. By limiting the relative size between the distance A and the dimension B, the distance between the solder mark 140 and the free end of the connecting piece 132 is limited to a suitable range. This ensures that the bending moment generated by the grooving force on the solder mark 140 is small during the grooving process, reducing the probability of the connecting piece 132 breaking at the position of the solder mark 140. This reduces the probability of the edge of the broken current collector 130 causing damage to the nearby first tab 124, thereby improving the conductivity and safety performance of the cylindrical battery 100. At the same time, the bending moment generated by the grooving force on the solder mark 140 is small, and the deformation stress transmitted from the position of the solder mark 140 to the periphery of the current collector 131 during the grooving process will also be reduced accordingly. This can reduce the downward pressure generated by the periphery of the current collector 131 on the nearby first electrode 124, and further reduce the damage to the electrode 124 caused by the current collector 130.

[0049] To further verify the relationship between the distance A between the solder mark 140 and the free end of the connecting piece 132 and the force at the position of the solder mark 140 during the grooving process, this application conducted two sets of grooving simulation tests on the grooving 113.

[0050] Both sets of simulation tests were conducted under the same three conditions: the cutter position was the same, the unfolded size of the connecting piece 132 was the same, and the grooving force was the same. In one set of simulation tests, the distance A between the solder mark 140 and the free end of the connecting piece 132 was greater than the distance A between the solder mark 140 and the free end of the connecting piece 132 in the other set of simulation tests. The set with the larger distance A was designated as the first set, and the set with the smaller distance A was designated as the second set.

[0051] It should be noted that the welding failure area of ​​sidewall 111 is located below weld mark 140, that is, on the side of weld mark 140 close to current collector 131, such as... Figure 8 and Figure 9 As shown in region I, this is determined by the current structural design, where the heat-affected zone from welding has a high risk of fracture. Therefore, during the experiment, the focus was on... Figure 8 Central Region I and Figure 9 The PEEQ (equivalent plastic strain) value of plastic deformation in region I was monitored. It should be noted that the PEEQ value in plastic deformation is an important physical quantity used to describe the degree of plastic strain accumulated in a material during plastic deformation. A higher PEEQ value indicates a higher risk of material fracture.

[0052] Please refer to the test results for Group 1. Figure 8 The simulation results are shown in the figure. For the test results of the second group, please refer to [link / reference]. Figure 9 The simulation results are shown in the figure. It is clear from the simulation results that the PEEQ value of the material in region I of the second group is lower than that of the material in region I of the first group. Therefore, the influence of the distance A between the solder mark 140 and the free end of the connecting piece 132 on the breakage of the connecting piece 132 during the grooving process can be qualitatively verified. That is, within a certain size range, the larger the distance A, the more easily the connecting piece 132 is to break.

[0053] Please see Figure 7 In one example of the cylindrical battery 100 of this utility model, the distance A is any value within the range of 0.2 to 1.0 mm, for example, the distance A can be 0.2 mm, 0.5 mm, or 1.0 mm. If the distance A is too small, during welding, the weld mark 140 is prone to problems such as undercut and poor weld appearance quality at the free end of the connecting piece 132. Considering that the unfolded size of the connecting piece 132 on the conventional current collector 130 is usually in the range of 3 to 5 mm, limiting the distance A to between 0.2 and 1.0 mm can meet the welding position requirements between most current collectors 130 and the side wall 111, and at the same time, it can further reduce the probability of the connecting piece 132 breaking at the weld mark 140 position during the grooving process.

[0054] Please see Figure 2 and Figure 7 In one example of the cylindrical battery 100 of this utility model, along the radial direction of the cylindrical battery 100, the distance from the point on the groove 113 closest to the axis of the housing 110 to the outer peripheral surface of the housing 110 is i, and the distance from the solder mark 140 to the outer peripheral surface of the housing 110 is j, where j ≤ 0.5i. It should be noted that the distance j from the solder mark 140 to the outer peripheral surface of the housing 110 specifically refers to the distance from the end of the solder mark 140 near the sidewall 111 to the outer peripheral surface of the housing 110. This limitation can reduce the tensile force generated at the solder mark 140 on the side of the groove 113 near the axis of the housing 110 during tensile deformation during the grooving process, thus improving the problem that the connecting piece 132 is easily broken at the solder mark 140.

[0055] Although the connecting piece 132 can be bent in various ways during the grooving process, to facilitate welding between the connecting piece 132 and the side wall 111, preferably, in an example of the cylindrical battery 100 of this utility model, please refer to... Figure 3 , Figure 4 and Figure 7 The connecting piece 132 includes a first connecting portion 1321 and a second connecting portion 1322 that are interconnected. The portion between the solder stamp 140 and the current collector body 131 is the first connecting portion 1321, and both ends of the first connecting portion 1321 are connected to the current collector body 131 and the second connecting portion 1322, respectively. The second connecting portion 1322 extends from the end of the first connecting portion 1321 near the solder stamp 140 toward the axis of the housing 110, forming the free end of the connecting piece 132. Furthermore, the second connecting portion 1322 is bent relative to the first connecting portion 1321 to form a first bent portion 1323. The extension direction of the second connecting portion 1322 can be consistent with the radial direction of the housing 110, or it can be set at an angle to the radial direction of the housing 110, as long as a stable welding relationship can be formed between the second connecting portion 1322 and the first groove wall 1131.

[0056] Please see Figure 4 The first bending portion 1323 extends circumferentially along the side wall 111, and a first weak structure 1325 is provided on the first bending portion 1323. Along the extension direction of the first bending portion 1323, the first weak structure 1325 can be a partial structure located in the middle or at both ends of the first bending portion 1323, or it can be an integral structure surrounding the entire first bending portion 1323. The specific structural form of the first weak structure 1325 can be varied, such as a through-hole structure opened on the first bending portion 1323, or a thinning zone structure formed on the first bending portion 1323, etc., as long as it can weaken the bending strength of the first bending portion 1323 and facilitate the bending and forming of the first bending portion 1323. By providing the first weak structure 1325 on the first bending portion 1323, the bending of the first bending portion 1323 can be facilitated, effectively releasing the bending stress generated during the bending process of the connecting piece 132, and reducing the probability of the connecting piece 132 breaking. Meanwhile, the first weak structure 1325 can also guide the bending of the first bend 1323, improving the accuracy of the bending position of the first bend 1323 and helping to improve the consistency of the assembly quality of the cylindrical battery 100. In addition, when the connecting piece 132 in front of the groove 113 is welded to the side wall 111, the first weak structure 1325 can also serve as a reference line for the welding position, facilitating the positioning of the welding head during welding.

[0057] Please see Figure 4In one example of the cylindrical battery 100 of this utility model, the first weak structure 1325 includes a first thinning region 1326 disposed on the first bending portion 1323. The first thinning region 1326 can take various forms, such as a grooved area formed by scribing the surface of the first bending portion 1323, or a thinning area formed by upsetting the surface of the first bending portion 1323. By providing the first thinning region 1326 on the first bending portion 1323, a bending weak portion can be formed on the first bending portion 1323, reducing the bending strength of the first bending portion 1323. This allows the connecting piece 132 to deform more quickly and promptly in the area of ​​the first bending portion 1323 during the grooving process, reducing the bending pressure generated during the bending of the connecting piece 132, thereby helping to reduce the probability of the connecting piece 132 breaking.

[0058] Please see Figure 4 In one example of the cylindrical battery 100 of this utility model, the first connecting portion 1321 is bent toward the center of the current collector body 131 relative to the current collector body 131, and a second bent portion 1324 is formed at the end of the first connecting portion 1321 near the current collector body 131. The provision of the second bent portion 1324 can reduce the transmission of deformation stress generated by the bending deformation of the connecting piece 132 during the grooving process to the current collector body 131, reduce the stress deformation of the current collector body 131, and thus effectively protect the stability of the welded connection between the current collector body 131 and the first electrode tab 124. The second bent portion 1324 extends circumferentially along the side wall 111, and a second weak structure 1327 is provided on the second bent portion 1324. The second weak structure 1327 can be a local structure provided in the middle or at both ends of the second bent portion 1324, or it can be an integral structure surrounding the entire second bent portion 1324, etc. The specific structural form of the second weak structure 1327 can be varied. For example, it can be a through-hole structure opened on the second bending portion 1324, or a thinning zone structure formed on the second bending portion 1324, as long as it can weaken the bending strength of the second bending portion 1324 and facilitate the bending and forming of the second bending portion 1324. By setting the second weak structure 1327 on the second bending portion 1324, it is convenient for the first connecting portion 1321 to bend at the end near the current collector body 131, thereby avoiding the bending stress generated by the first connecting portion 1321 from being transmitted to the current collector body 131 and causing tearing of the welded connection between the current collector body 131 and the first electrode tab 124, and improving the stability of the electrical connection between the current collector body 131 and the electrode assembly 120. Meanwhile, the second bending portion 1324 can also weaken the bending pressure accumulated at the edge of the current collector body 131, thereby reducing the downward pressure generated by the edge of the current collector body 131 on the first electrode tab 124 side, which is beneficial to reduce the pressure damage of the current collector body 131 on the first electrode tab 124.

[0059] In one example of the cylindrical battery 100 of this utility model, the second weak structure 1327 includes a second thinning region 1328 disposed on the second bending portion 1324. The structure of the second thinning region 1328 may be the same as or similar to the weak structure of the first thinning region 1326, or it may be different from the weak structure of the first thinning region 1326. In this embodiment, it is not limited to this. For example, it may be a grooved area formed by scribing the surface of the second bending portion 1324, or it may be a thinning area formed by upsetting the surface of the second bending portion 1324, etc. By providing a second thinning region 1328 in the second bending portion 1324, a bending weak portion can be formed in the second bending portion 1324, reducing the bending strength of the second bending portion 1324. This allows the connecting piece 132 to deform more quickly and promptly in the area of ​​the second bending portion 1324 during the grooving process, further reducing the accumulation of bending pressure at the periphery of the current collector body 131 and reducing the probability of the current collector body 131 damaging the first electrode tab 124.

[0060] It should be noted that, in one embodiment, the second thinning region 1328 may be provided only in the second bend portion 1324, such as... Figure 11 As shown. In another embodiment, the first bending portion 1323 may be provided with a first thinning region 1326, while the second bending portion 1324 may be provided with a second thinning region 1328, as shown. Figure 10 As shown.

[0061] In one example of the cylindrical battery 100 of this utility model, the thickness D1 of the connecting piece 132 is smaller than the thickness D2 of the current collector body 131. For example... Figure 12 As shown. There are several ways to make the thickness D1 of the connecting piece 132 smaller than the thickness D2 of the current collector body 131. For example, the thickness D1 of the connecting piece 132 can be reduced by partially sealing the connecting piece 132; alternatively, the connecting piece 132 and the current collector body 131 can be separate welded components, and during the manufacturing process of the current collector component 130, a thinner material can be directly used to make the connecting piece 132, thus achieving a thinner connecting piece 132. By making the thickness D1 of the connecting piece 132 smaller than the thickness D2 of the current collector body 131, the bending of the connecting piece 132 can be facilitated, reducing the deformation stress generated during the bending process. This also reduces the accumulated bending stress in the material at the weld mark 140 area, thereby reducing the probability of the connecting piece 132 breaking at the weld mark 140 location.

[0062] Please see Figure 13This utility model also provides a battery pack 10, which includes the cylindrical battery 100 described above. In one embodiment of the battery pack 10, the battery pack 10 includes a housing 101, a cover 102, and multiple cylindrical batteries 100. The multiple cylindrical batteries 100 are placed in the housing 101 and connected in series or parallel, or a combination of series and parallel connections. The cover 102 seals the housing 101 to protect the multiple cylindrical batteries 100. It should be noted that, in addition to the cylindrical battery 100 of this utility model, the battery pack 10 may also include a thermal management system, circuit board, etc. The battery pack 10 can be a battery module, a battery pack, an energy storage cabinet, etc.; these will not be described in detail here.

[0063] Please see Figure 14 This utility model also provides an electronic device 1, which includes the aforementioned battery pack 10. A working part 11 is electrically connected to the battery pack 10 to obtain electrical power. As an example, the electronic device 1 is a vehicle, which can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part 11 is the vehicle body, and the battery pack 10 is located at the bottom of the vehicle body, providing electrical power for the vehicle's operation or the operation of its internal electrical components. However, in other embodiments, the electronic device 1 can also be a mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part 11 can be a unit component capable of obtaining electrical power from the battery pack 10 and performing corresponding work, such as a fan blade rotation unit or a vacuum cleaner suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electronic device 1.

[0064] In this cylindrical battery, along the radial direction of the current collector body, the distance A from the free end of the connecting piece to the side of the solder mark near the center of the current collector body is set, and the unfolded dimension of the connecting piece is B. The distance A is less than or equal to 1 / 3 of dimension B. This setting limits the distance between the solder mark and the free end of the connecting piece within a suitable range by restricting the relative size of distance A and dimension B. This ensures that the bending moment generated by the grooving force on the solder mark is small during the grooving process, reducing the probability of the connecting piece breaking at the solder mark location. This reduces the probability of the edge of the current collector component damaging the nearby first electrode tab after breakage, thus improving the conductivity and safety performance of the cylindrical battery. Simultaneously, the smaller bending moment generated by the grooving force on the solder mark also reduces the deformation stress transmitted from the solder mark location to the periphery of the current collector body during the grooving process. This reduces the downward pressure exerted by the periphery of the current collector body on the nearby first electrode tab, further reducing the damage to the electrode tab caused by the current collector component. Therefore, this invention effectively overcomes some practical problems in the prior art and has high utilization value and significance. The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A cylindrical battery, characterized in that, include: A housing includes a sidewall with an opening, the sidewall having a groove recessed into the interior of the housing near the opening, the groove including a first groove wall on a side opposite to the opening; An electrode assembly is disposed within the housing, and the electrode assembly includes a first tab on the side facing the opening; the groove restricts the axial displacement of the electrode assembly within the housing. A current collecting component is at least partially disposed between the first electrode tab and the groove; the current collecting component includes a current collecting body and a connecting piece connected to the periphery of the current collecting body, the current collecting body is electrically connected to the first electrode tab, and the connecting piece is bent toward the axis of the housing and welded to the wall of the first groove to form a weld mark. Wherein, along the radial direction of the current collector body, the distance from the free end of the connecting piece to the side of the solder mark near the center of the current collector body is A, the unfolded size of the connecting piece is B, and the distance from A is less than or equal to 1 / 3 of the size B.

2. The cylindrical battery according to claim 1, characterized in that, The distance A ranges from 0.2 to 1.0 mm.

3. The cylindrical battery according to claim 1, characterized in that, Along the radial direction of the cylindrical battery, the distance from the point on the groove closest to the axis of the housing to the outer peripheral surface of the housing is i, and the distance from the solder mark to the outer peripheral surface of the housing is j, where j≤0.5i.

4. The cylindrical battery according to claim 1, characterized in that, The connecting piece includes a first connecting portion and a second connecting portion that are connected to each other. The portion located between the solder mark and the current collector body is the first connecting portion. The second connecting portion extends from the end of the first connecting portion near the solder mark toward the axis of the housing and is bent relative to the first connecting portion to form a first bent portion. The first bent portion includes a first weak structure.

5. The cylindrical battery according to claim 4, characterized in that, The first weak structure includes a first thinning region.

6. The cylindrical battery according to claim 4, characterized in that, The first connecting portion bends relative to the current collecting body toward the center of the current collecting body to form a second bending portion, and the second bending portion includes a second weak structure.

7. The cylindrical battery according to claim 6, characterized in that, The second weak structure includes a second thinning zone.

8. The cylindrical battery according to any one of claims 1 to 3, characterized in that, The thickness of the connecting piece is less than the thickness of the current collecting body.

9. A battery pack, characterized in that, The cylindrical battery includes any one of claims 1 to 8.

10. An electronic device, characterized in that, Includes the battery pack as described in claim 9.

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