Cylindrical type battery cell, battery assembly and electronic device

Abstract

To provide a cylindrical type battery cell which is affected by relative displacement in a radial direction between a current collector and a roll groove, and has improved conductive stability between the current collector and a housing.SOLUTION: A cylindrical type battery cell includes a housing 110, an electrode assembly 120, and a current collector 130. The housing includes an opening 114, and a roll groove 113 is formed on the side wall of the opening. The electrode assembly is arranged so as to be sealed in the housing, and the roll groove restricts movement in an axial direction of the electrode assembly. A first tab is arranged on one side of the electrode assembly facing the opening. The current collector is arranged in the housing, and includes a housing connection part 133 which is connected to one side away from the electrode assembly of the roll groove, and a tab connection part 132 which is connected to the first tab. In the housing connection part, a positioning part 140 for regulating displacement in a radial direction of the housing connection part is installed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to the field of battery technology, and more particularly to cylindrical battery cells, battery assemblies, and electronic devices. [Background technology]

[0002] At present, the 46 series large cylindrical battery cells are increasingly supported by major automobile companies due to their high safety, long service life, excellent fast charging performance, excellent battery consistency, and low production costs. At present, the mainstream of large cylindrical battery cells is a full-tab design, with the positive and negative electrodes arranged on the same side. The full-tab winding core is connected to the electrode pole and the housing via the positive and negative current collectors, respectively, so that the positive and negative electrodes are arranged on the same side. When connecting the current collector to the housing, in order to form a relatively stable welding surface, it is necessary to form a processing groove in the opening of the housing, and then firmly press the housing connection part of the current collector against the welding surface by applying tool pressure, and finally weld it to make the housing negatively charged. In the process of pressing the housing connection part against the welding surface, the relative displacement in the radial direction between the housing connection part and the roll groove of the housing is very easy to occur, so it is difficult to ensure a stable welding surface between the current collector and the roll groove, and the welding quality is easily deteriorated. Summary of the Invention [Problem to be solved by the invention]

[0003] In consideration of the above-mentioned shortcomings of the related art, the present invention provides a cylindrical battery cell, a battery assembly and an electronic device to solve the technical problem of conductive stability between a current collector and a housing, which is affected by the relative displacement in the radial direction between the current collector and the roll groove. [Means for solving the problem]

[0004] In order to achieve the above and other related objects, the present invention provides a cylindrical battery cell including a housing, an electrode assembly, and a current collector. The housing includes an opening, and a side wall of the opening is formed with a roll groove. The electrode assembly is sealed and disposed within the housing, and the roll groove limits the movement of the electrode assembly in an axial direction. The first tab is disposed on one side of the electrode assembly facing the opening. The current collector is disposed within the housing, and the current collector includes a housing connection portion, a tab connection portion, and a connection arm. The housing connection portion is connected to the tab connection portion via the connection arm. The housing connection portion is connected to one side of the roll groove away from the electrode assembly, and the tab connection portion is connected to the first tab. Here, a positioning portion is provided on the housing connection portion and / or the connection arm, and the positioning portion is provided to restrict radial displacement of the housing connection portion.

[0005] In one example of the cylindrical battery cell of the present invention, the current collector further includes a plate body, the housing connection part and the plate body are connected via a connection arm, the housing connection part extends along the circumferential direction of the housing, the positioning part is formed by the housing connection part extending toward the electrode assembly along the height direction of the housing, and the positioning part abuts against the inner wall of the roll groove.

[0006] In one example of the cylindrical battery cell of the present invention, at least two positioning portions are provided on the housing connection portion, and the at least two positioning portions are located on both sides of the connection arm.

[0007] In one example of the cylindrical battery cell of the present invention, the positioning portion is formed by a connection arm that extends toward the electrode assembly along the height direction of the housing, and the positioning portion abuts against the inner wall of the roll groove.

[0008] In one example of the cylindrical battery cell of the present invention, an obtuse angle is formed between the positioning portion and the housing connection portion.

[0009] In one example of the cylindrical battery cell of the present invention, the stress buffer structure is disposed on the connecting arm.

[0010] In one embodiment of the cylindrical battery cell of the present invention, the connection arm, the housing connection portion and the plate body are integrally formed. The connection arm includes a plurality of curved portions, and the curved portions are deformed when pressed.

[0011] In one example of the cylindrical battery cell of the present invention, the connection arm and the housing connection portion are independent components, and the connection arm is made of a flexible material.

[0012] In one example of the cylindrical battery cell of the present invention, a seal ring is disposed on one side of the roll groove away from the electrode assembly, and an avoidance structure is provided on the end face of the seal ring facing the housing connection portion.

[0013] In one example of the cylindrical battery cell of the present invention, the avoidance structure is an annular groove structure, and the housing connection portion is housed within the annular groove structure.

[0014] In one example of the cylindrical battery cell of the present invention, the connection arm is disposed between adjacent tab connections, and the connection arm and the tab connections are partially separated.

[0015] In one example of a cylindrical battery cell of the present invention, an exhaust hole is disposed in the center of the current collector, and a notch is provided in the side wall along the periphery of the exhaust hole.

[0016] The present invention provides a battery assembly including a cylindrical battery cell as described in any one of the above examples.

[0017] The present invention further provides an electronic device including a battery assembly. Effect of the Invention

[0018] In the cylindrical battery cell of the present invention, a positioning portion is provided on the housing connection portion and / or the connection arm of the current collector, and the positioning portion is provided so as to limit the radial displacement of the housing connection portion. With this configuration, on the one hand, it is possible to accurately position the current collector in the radial direction of the housing in the process of pressing the housing connection portion against the roll groove, which improves the contact between the housing connection portion and the roll groove, forms a stable current-carrying area between the current collector and the housing, and improves the stability of the current-carrying ability of the battery cell. On the other hand, improving the positioning accuracy between the housing and the current collector improves the quality stability during the cell assembly process, thereby improving the stability of the performance of the battery cell. [Brief description of the drawings]

[0019] In order to more clearly describe the embodiments of the present invention or the technical solutions of the prior art, the drawings necessary for describing the embodiments or related art are briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. Those skilled in the art can obtain other drawings based on these drawings without creative efforts. [Figure 1] 1 is a schematic diagram showing the overall structure of one embodiment of a cylindrical battery cell of the present invention. [Diagram 2] FIG. 4 is a schematic diagram showing the arrangement position between a current collector and a roll groove in one embodiment of a cylindrical battery cell of the present invention. [Diagram 3] FIG. 2 is a schematic diagram showing the overall structure of a current collector in one embodiment of a cylindrical battery cell of the present invention. [Figure 4] FIG. 2 is a top view showing the schematic arrangement of current collectors and roll grooves in one embodiment of a cylindrical battery cell of the present invention. [Diagram 5] FIG. 5 is a partial enlarged view of region C in FIG. [Figure 6] 1 is a cross-sectional view showing the overall structure of a housing in one embodiment of a cylindrical battery cell of the present invention. [Figure 7] FIG. 2 is a cross-sectional view showing a partial structure after the opening of the casing in one embodiment of the cylindrical battery cell of the invention has been pier-sealed. [Figure 8]FIG. 11 is a cross-sectional view showing a partial structure of a cylindrical battery cell according to another embodiment of the present invention before the opening of the casing is peer-sealed. [Figure 9] FIG. 2 is a cross-sectional view showing the overall structure of a seal ring in one embodiment of a cylindrical battery cell of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The present invention will be described below with reference to specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations. Various details of this specification can also be modified or changed in various ways based on different perspectives and applications without departing from the spirit of the present invention. In addition, the following embodiments and the characteristic parts in each embodiment may be combined as long as there is no contradiction between each embodiment. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments and are not intended to limit the scope of the present invention. In the following examples, test methods that do not specify specific conditions usually adopt conventional conditions or conditions recommended by each manufacturer.

[0021] When numerical ranges are provided in the embodiments, it should be understood that the two end points of each numerical range and any value between the two end points can be selected unless otherwise specified in the present invention. Unless otherwise defined, all technical and scientific terms used in the present invention are consistent with the knowledge of the relevant art and the description of the present invention by those skilled in the art. They may be used with the methods and methods described in the embodiments of the present invention. The devices and materials are similar or equivalent to any methods, devices and materials of the relevant art for carrying out the present invention.

[0022] It should be noted that terms such as "upper", "lower", "left", "right", "middle", and "one side" used in this specification are used solely for convenience of explanation and are not used to limit the scope of this specification. As for the scope of the present invention, changes and adjustments of relative relationships are also included in the scope of the present invention as long as there is no substantial change in the technical content.

[0023] Please refer to Figs. 1 to 9. The present invention provides a cylindrical battery cell 100 and an electronic device. The cylindrical battery cell 100 may be positioned in the radial direction during the process of pressing and connecting the housing connection part 133 and the housing 110, thereby improving the positioning accuracy of the configuration between the current collector 130 and the housing 110. Furthermore, a smooth welding surface is obtained between the housing connection part 133 and the roll groove 113, thereby forming a stable current-carrying region between the current collector 130 and the housing 110, and improving the stability of the current-carrying capacity of the cylindrical battery cell 100.

[0024] Please refer to FIG. 1 to FIG. 6. The cylindrical battery cell 100 includes a housing 110, an electrode assembly 120, and a current collector 130. The housing 110 is formed with a receiving cavity for receiving the electrode assembly 120, an electrolyte (not shown), and other components. The receiving cavity may be open at one end or at both ends. Specifically, the shape of the housing 110 can be determined according to the specific dimensions of the electrode assembly 120. The housing 110 can be made of various materials such as copper, iron, aluminum, steel, and aluminum alloy. To prevent the housing from rusting due to long-term use, the surface of the housing can be plated with a layer of an anti-rust material such as metallic nickel. In one example of the cylindrical battery cell 100 of the present invention, the housing 110 includes an end wall 111 and a side wall 112 surrounding the end wall 111. The side wall 112 and the end wall 111 together form a cylinder having a closed end and an opening 114 at the other end. A roll groove 113 is formed in the side wall 112 near the opening 114 of the housing 110, the roll groove 113 being recessed toward the inside of the housing 110. A relatively smooth welding surface 1131 is formed on one side of the roll groove 113 away from the electrode assembly 120.

[0025] The electronic component 120 is sealed in the housing 110, but the sealing method is not particularly limited. The electrode assembly 120 is a component in the battery cell where an electrochemical reaction occurs. The housing 110 may include one or more electrode assemblies 120. The electrode assembly 120 is mainly formed by winding or laminating a positive electrode sheet and a negative electrode sheet, and a separator is usually disposed between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector includes a positive electrode coating area and a positive electrode tab connected to the positive electrode coating area. The positive electrode collector includes a positive electrode coating area and a positive electrode tab connected to the positive electrode coating area. The positive electrode coating area is coated with the positive electrode active material layer, and the positive electrode tab is not coated with the positive electrode active material layer. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector includes a negative electrode coating region and a negative electrode tab connected to the negative electrode coating region. The negative electrode coating region is coated with the negative electrode active material layer, and the negative electrode tab is not coated with the negative electrode active material layer. Taking a lithium ion battery as an example, the material of the positive electrode current collector is aluminum, and the positive electrode active material layer includes a positive electrode active material. The positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The material of the negative electrode current collector may be copper, and the negative electrode active material layer may include a negative electrode active material. The negative electrode active material may be carbon, silicon, etc. The material of the separator may be PP (polypropylene), PE (polyethylene), etc. In order to protect and insulate the battery cell, the battery cell may be covered with an insulating film. The insulating film may be synthesized from PP, PE, PET (polyethylene terephthalate), PVC (polyvinyl chloride), or other polymer materials.

[0026] Please refer to Figures 6 and 7. The end cap 160 is sealingly connected to the opening 114 of the housing 110. The current collector 130 is disposed between the end cap 160 and the electrode assembly 120. One end of the current collector 130 is electrically connected to the negative electrode tab of the electrode assembly 120. The other end of the current collector 130 is electrically connected to the housing 110, so that the entire housing 110 is negatively charged. An explosion-proof valve is disposed in the end cap 160. When the cylindrical battery cell 100 experiences thermal runaway, high-temperature gas generated in the electrode assembly 120 is exhausted through the explosion-proof valve, thereby realizing an explosion in the axial direction of the cylindrical battery cell 100.

[0027] When assembling the cylindrical battery cell 100, first, the electrode assembly 120 is placed in the housing 110, and then a rolling groove 113 is formed in the side wall 112 of the housing 110 close to the opening 114 to axially position the electrode assembly 120. After that, the current collector 130 is placed so that one end of the current collector 130 is welded to the rolling groove 113 and the other end of the current collector 130 is welded to the negative tab of the electrode assembly 120. Finally, the seal ring 150 and the end cap 160 are placed in the opening 114. The assembly process of the cylindrical battery cell 100 is completed by piercing the housing 110 at the opening 114 and sealing the end cap 160 onto the housing 110.

[0028] Please refer to Figs. 2 to 7 for an example of a cylindrical battery cell 100 of the present invention. The electrode assembly 120 is sealed in the housing 110 and is located between the rolling groove 113 and the end wall 111 of the housing 110. The rolling groove 113 limits the movement of the electrode assembly 120 in the axial direction of the housing 110. A first tab 121 and a second tab are respectively arranged at both ends of the electrode assembly 120 in the longitudinal direction, and the polarity of the first tab 121 is opposite to that of the second tab. Here, the first tab 121 faces the opening 114 of the housing 110, and the first tab 121 is a negative electrode tab. Note that in other examples, the first tab 121 may be a positive electrode tab.

[0029] Please refer to FIG. 2 to FIG. 5. In one example of the cylindrical battery cell 100 of the present invention, the current collector 130 is disposed in the housing 110. The current collector 130 includes a housing connection part 133, a tab connection part 132, and a connection arm 134. One end of the connection arm 134 is connected to the housing connection part 133, and the other end of the connection arm 134 is connected to the tab connection part 132. The housing connection part 133 is disposed on the outer periphery of the tab connection part 132, and the housing connection part 133 is welded to the welding surface 1131 of the roll groove 113. The tab connection part 132 is electrically connected to the first tab 121, thereby realizing that the housing 110 and the first tab 121 have the same electrical characteristics. The number and specific structural form of the housing connection parts 133 and the tab connection part 132 are not particularly limited as long as a stable electrical connection relationship can be formed between the housing 110 and the first tab 121. The positioning unit 140 is installed in the housing connection unit 133. The positioning unit 140 is installed to restrict the displacement of the housing connection unit 133 in the radial direction of the housing 110. The specific structural form of the positioning unit 140 is not particularly limited as long as it can restrict the displacement of the housing connection unit 133 in the radial direction of the housing 110. The positioning unit 140 may restrict the displacement of the housing connection unit 133 in the radial direction by any position restriction method, such as abutting against the inner wall of the housing 110 or abutting against the inner wall 1132 of the roll groove 113. In another embodiment, the positioning unit 140 is not arranged in the housing connection unit 133, but is arranged in the connection arm 134. Even with such a configuration, the effect of restricting the displacement of the housing connection unit 133 in the radial direction of the housing 110 can be realized. In another embodiment, the positioning unit 140 may be arranged in both the housing connection unit 133 and the connection arm 134. With such a configuration, the above-mentioned effect can also be realized. In the process of connecting the housing connection part 133 and the roll groove 113, the housing connection part 133 needs to approach the roll groove 113 under the action of the tool pressure until the housing connection part 133 is completely pressed against the welding surface 1131 of the roll groove 113. In this process, the housing connection part 133 approaches the roll groove 113 along the radial direction of the electrode assembly 120, so that a certain displacement occurs in the radial direction.The housing connection portion 133 is free in the radial direction during press processing, resulting in deviation in radial displacement, which affects the welding area of ​​the housing connection portion 133 on the welding surface 1131 of the roll groove 113, and ultimately affects the conductive stability of the housing 110 and the current collector 130. By providing the positioning portion 140 on the housing connection portion 133, a radial position restriction function can be exerted in the pressing process of the housing connection portion 133, thereby accurately controlling the amount of radial displacement and achieving accurate positioning and connection of the housing connection portion 133 in the radial direction of the roll groove 113. In this way, the stability of the welding area between the housing connection portion 133 and the roll groove 113 is improved, and the stability of the current-carrying capacity of the entire cylindrical battery cell 100 is improved. At the same time, the configuration and positional accuracy between the housing 110 and the current collector 130 are improved, improving the stability of the assembly quality of the cylindrical battery cell 100, thereby improving the stability of the performance of the cylindrical battery cell 100.

[0030] Please refer to FIG. 2 to FIG. 5. In one example of the cylindrical battery cell 100 of the present invention, the current collector 130 further includes a plate body 131. The plate body 131 is located at the center of the current collector 130, and the connection arm 134 is located at the outer periphery of the current collector 130. The connection arm 134 is radially distributed along the center of the current collector 130. One end of the connection arm 134 is connected to the plate body 131, and the other end of the connection arm 134 is connected to the housing connection part 133. The housing connection part 133 extends along the circumferential direction of the housing 110 to form an arc-shaped plane. A positioning part extending toward the electrode assembly 120 side is formed on the side wall of the arc-shaped plane close to the axis of the current collector 130, and the positioning part 140 abuts against the inner wall 1132 of the roll groove 113. With this configuration, the positioning part 140 is relatively close to the housing connection part 133, and a better positioning effect can be obtained. When the housing 110 is later pierced and sealed, the positioning portion 140 is less likely to interfere with the seal ring 150 on the roll groove 113, making it easier to seal the components in a later process. The positioning portion 140 may be formed integrally with the housing connection portion 133, or may be formed separately and connected by welding, as long as the connection strength requirements of the positioning portion 140 are satisfied. The positioning portion 140 may adopt various structures, such as a flat plate structure, a cylindrical structure, and a circular arc plate structure, as long as the structure can abut against the inner wall 1132 of the roll groove 113. Preferably, in order to facilitate molding and reduce manufacturing costs, in one example of the present invention, the positioning portion 140 has a flat plate structure. With this configuration, in the process of pressing the housing connection part 133, the flat plate structure comes into line contact with the inner side wall 1132 of the roll groove 113, thereby reducing the sliding resistance between the positioning part 140 and the inner side wall 1132 of the roll groove 113, thereby reducing the possibility of damaging the positioning part 140 or the inner side wall 1132 of the roll groove 113 in the pressing process. Therefore, the positioning accuracy in the radial direction of the roll groove 113 by the positioning part 140 of the housing 110 can be improved. In another embodiment, the positioning part 140 may be an arc plate structure corresponding to the curvature of the inner side wall 1132 of the roll groove 113. With this configuration, a large contact area can be formed with the inner side wall 1132 of the roll groove 113, and higher resistance strength can be obtained.However, the forming process of the arc plate structure is complicated, and the manufacturing cost is high. In addition, in the process of pressing the housing connection part 133, the arc plate and the inner wall 1132 of the roll groove 113 are in surface contact with each other, so that the sliding resistance between the positioning part 140 and the inner wall 1132 of the roll groove 113 is large, and it is highly likely that the positioning part 140 and the inner wall 1132 of the roll groove 113 are damaged during the pressing process. As a result, the positioning accuracy of the positioning part 140 of the housing 110 in the radial direction of the roll groove 113 may decrease.

[0031] In the present invention, the number and specific positions of the positioning parts 140 installed in the housing connection part 133 are not limited, but preferably, refer to Figs. 2 to 5. In one example of the cylindrical battery cell 100 of the present invention, at least two positioning parts 140 are arranged in the housing connection part 133, and at least two positioning parts 140 are arranged on both sides of the connection arm 134. The positioning parts 140 may be arranged close to both sides of the connection arm 134, or may be arranged at a certain distance from both sides of the connection arm 134. The number of positioning parts 140 on both sides of the connection arm 134 is not limited, and the number of positioning parts 140 on both sides of the connection arm 134 may be the same or different. With this configuration, by forming positioning fulcrums on both sides of the housing connection part 133, it is possible to improve the positioning strength and positioning accuracy in the positioning process. In one embodiment of the present invention, two positioning parts 140 are arranged on the housing connection part 133, and the two positioning parts 140 are arranged symmetrically on both sides of the connection arm 134, and the two positioning parts 140 are located at both ends of the housing connection part 133 in the circumferential extension direction. With this configuration, symmetric support strength is obtained at both ends of the housing connection part 133, and the force is applied to the housing connection part 133 more uniformly. This reduces the stress applied to the housing connection part 133, and improves the stability of the welding between the housing connection part 133 and the roll groove 113. At the same time, since the positioning parts 140 are arranged only at both ends of the housing connection part 133, the dimension of the positioning parts 140 is relatively independent of the circumferential extension dimension of the housing connection part 133. When the circumferential extension dimension of the housing connection portion 133 needs to be increased in accordance with the required current-carrying capacity, there is no need to increase the dimension of the positioning portion 140, and since the dimension of the positioning portion 140 is small, the positioning portion 140 can slide easily against the inner wall 1132 of the roll groove 113, thereby reducing the possibility of damage to the positioning portion 140 or the inner wall 1132 of the roll groove 113 during the pressing process.

[0032] In one example of the cylindrical battery cell 100 of the present invention, the positioning portion 140 is formed by a connection arm 134 extending toward the electrode assembly 120 along the height direction of the housing 110, and the positioning portion 140 abuts against the inner wall 1132 of the roll groove 113. The positioning portion 140 and the connection arm 134 may be integrally formed, or may be formed separately and connected by welding, as long as the connection strength requirements of the positioning portion 140 are satisfied. This configuration can also achieve the radial positioning effect of the housing connection portion 133. In addition, the positioning portion 140 does not easily interfere with the seal ring 150 on the roll groove 113, making it easier to seal the subsequent components. However, the positioning effect is inferior to the case where the positioning portion 140 is directly disposed on the housing connection portion 133 .

[0033] For an example of the cylindrical battery cell 100 of the present invention, please refer to Figures 2, 7 and 8. An obtuse angle α is formed between the positioning portion 140 and the housing connection portion 133, and the roll groove 113 is arranged in the area where the obtuse angle α is arranged. When the housing connection portion 133 and the roll groove 113 are welded, the angle between the positioning portion 140 and the housing connection portion 133 becomes 90 degrees, which serves the function of positioning by welding. After the welding is completed and the housing 110 is pierced and sealed at the opening 114, the roll groove 113 exerts a radial force on the positioning portion 140 toward the axis of the electrode assembly 120 due to the radial deformation of the roll groove 113. This increases the angle between the positioning portion 140 and the housing connection portion 133, forming the obtuse angle α. By setting an obtuse angle α between the housing connection portion 133 and the positioning portion 140, the vertical distance between the lower end of the positioning portion 140 and the electrode assembly 120 is increased, reducing the possibility that the positioning portion 140 will be inserted into the electrode assembly 120 and damage the electrode sheet when the housing 110 is pierced and sealed.

[0034] Please refer to FIG. 2 and FIG. 3 for an example of the cylindrical battery cell 100 of the present invention. The connection arm 134 is provided with a stress buffer structure that reduces the stress transmitted to the tab connection portion 132 and the plate body 131 during pier-sealing. When the housing 110 is pier-sealed, a large compressive stress is generated in the housing connection portion 133. The compressive stress is transmitted to the tab connection portion 132 through the connection arm 134, affecting the stability of the welding of the tab connection portion 132. By providing a stress buffer structure in the connection arm 134, a part of the stress transmitted from the housing connection portion 133 can be alleviated. On the one hand, the stress transmitted to the tab connection portion 132 is reduced, and the stability of the welding connection of the tab connection portion 132 is improved. On the other hand, the stress applied to the plate body 131 can be reduced, so that the stress deformation generated in the plate body 131 is reduced, thereby reducing the possibility that the plate body 131 will be torn or broken due to excessive stress deformation. The stress buffering structure may be any structure that can provide a stress buffering function, such as a curved structure or a flexible material for connection, and is not limited thereto.

[0035] Please refer to FIG. 2 and FIG. 3. In one example of the cylindrical battery cell 100 of the present invention, the connection arm 134 is integrally connected to the housing connection part 133 and the plate body 131. The connection arm 134 includes a plurality of curved parts 1341, and the curved parts 1341 are deformed when pressed. The bending angle of the curved parts 1341 is arbitrary, and the shape of the curved parts 1341 may be a combination of a plurality of shapes, or a single shape may be repeatedly arranged. For example, the curved parts 1341 may be an arrangement of a plurality of arc-shaped protrusions, or may have a wave-shaped structure consisting of a plurality of undulations or the like. In one example of the present invention, referring to FIG. 2 and FIG. 3, there is a height difference between the housing connection part 133 and the plate body 131 along the height direction of the housing 110. One end of the connection arm 134 is connected to the lower layer of the plate body 131, and the other end of the connection arm 134 is connected to the upper and lower parts of the plate body 131. A plurality of curved parts 1341 are provided at the connection positions of the connection arm 134 and the plate body 131. The multiple curved portions 1341 are connected in sequence to form a protrusion in a direction away from the electrode assembly 120. This configuration not only achieves a stress buffering function, reduces the transmission of stress to the connection arm 134, and improves the stability of the welding of the tab connection portion 132, but also forms a smooth transition connection between the connection arm 134 and the plate body 131, reduces the stress concentration at that position, and improves the connection strength between the connection arm 134 and the plate body 131.

[0036] In one example of the cylindrical battery cell 100 of the present invention, the connection arm 134 and the housing connection part 133 are independent parts, and the connection arm 134 is made of a flexible material. The flexible material may be any flexible material that satisfies the requirements of electrical conductivity and connection strength, such as a conductor formed by laminating multiple layers of metal foil. One end of the connection arm 134 is connected to the housing connection part 133, and the other end of the connection arm 134 is connected to the plate body 131. The connection method of the connection arm 134, the housing connection part 133, and the plate body 131 may be welding or riveting that satisfies the requirements of connection strength and electrical conductivity performance. By making the connection arm 134 from a flexible material, the flexible material can buffer the stress transmitted to the connection arm 134 due to deformation, and therefore the stress transmitted from the housing connection part 133 to the tab connection part 132 via the connection arm 134 can be alleviated, thereby reducing the stress deformation generated in the tab connection part 132 and improving the stability of the welding of the tab connection part 132. At the same time, the stress applied to the plate body 131 is reduced, and the possibility that the plate body 131 will break or be damaged due to a large stress deformation is reduced.

[0037] Please refer to FIG. 4 to FIG. 9. In one example of the cylindrical battery cell 100 of the present invention, a seal ring 150 is disposed on one side of the roll groove 113 away from the electrode assembly 120, and an avoidance structure 151 is provided on an end surface of the seal ring 150 facing the housing connection portion 133 to avoid a welding mark 1331 formed in the roll groove 113 by the housing connection portion 133. The avoidance structure 151 may be an annular groove structure or a plurality of local cutout structures, and the size and number of the cutouts are consistent with the number and size of the housing connection portion 133. In one embodiment of the present invention, please refer to FIG. 9. The avoidance structure 151 is an annular groove structure. By providing the avoidance structure 151, an avoidance space in which the housing connection portion 133 is accommodated may be formed between the seal ring 150 and the roll groove 113. When the housing 110 is pierced, the pressing force of the seal ring 150 on the housing connection portion 133 is reduced, thereby reducing the possibility of the welding mark 1331 of the housing connection portion 133 being damaged and causing a failure. Therefore, the stability of the welded connection between the housing connection portion 133 and the roll groove 113 is improved.

[0038] Please refer to Figs. 2 to 4. In one example of the cylindrical battery cell 100 of the present invention, the plate body 131 is disposed at the center of the current collector 130, the tab connection portion 132 is disposed along the circumferential direction of the plate body 131, and the connection arm 134 is disposed between adjacent tab connection portions 132. One end of the connection arm 134 in the length direction is connected to the plate body 131, and the other end of the connection arm 134 in the length direction is connected to the housing connection portion 133. The hollow region 136 is disposed on both sides of the width direction of the connection arm 134, and the connection arm 134 is supported in a cantilever shape along the length direction between two adjacent tab connection portions 132. By disposing the hollow region 136, the connection arm 134 and the adjacent tab connection portion 132 are partially separated. With this configuration, the stress transmitted from the connection arm 134 to the tab connection portion 132 can be further reduced, thereby reducing the stress deformation of the tab connection portion 132 and improving the stability of the welded connection of the tab connection portion 132. It should be noted that the specific structural form of the hollow region 136 is not particularly limited. The hollow region 136 may have any structural shape, such as a long structure, a square structure, etc. The area of ​​the hollow region 136 is not particularly limited as long as it satisfies the requirements for current induction of the connection arm 134 and the requirements for the welding strength of the tab connection portion 132. Preferably, in this embodiment, the hollow region 136 is a wedge-shaped structure, and one end of the wedge-shaped structure having a large opening faces the housing connection portion 133. With this configuration, when the connection arm 134 is deformed in the process of pressing the housing connection portion 133, it is difficult to contact the adjacent tab connection portions 132 on both sides, which not only avoids the transmission of stress, but also ensures the connection strength between the connection arm 134 and the plate body 131.

[0039] Please refer to Figures 2 and 3. In one example of the cylindrical battery cell 100 of the present invention, an exhaust hole 135 is provided at the center of the current collector 130, and a notch 1351 is provided on the side wall along the periphery of the exhaust hole 135. The shape and number of the notch 1351 are not particularly limited, and for example, the notch 1351 may be rectangular, triangular, or pointed. When thermal runaway occurs in the cylindrical battery cell 100, it is necessary to quickly exhaust the high-temperature gas in the cylindrical battery cell 100 through the explosion-proof valve of the end cap 160 to achieve an axial directional explosion, reduce the accumulation of high-temperature gas inside the cylindrical battery cell 100, and avoid the lateral explosion of the cylindrical battery cell 100. By providing the notch 1351, the current collector 130 forms a weak area at the notch 1351. When thermal runaway occurs in the cylindrical battery cell 100, the action of high temperature and pressure will cause the current collector 130 to form a crack at the notch 1351, and the current collector 130 will be rapidly torn apart, and the high-pressure gas in the electrode assembly 120 will be rapidly discharged, and the pressure will be rapidly released, reducing the possibility of lateral explosion of the cylindrical battery cell 100.

[0040] The present invention further provides a battery assembly including the cylindrical battery cell 100 described in any one of the above examples, in which a plurality of the cylindrical battery cells 100 are connected in series or in parallel, or a battery module and a battery pack formed by combining a plurality of the cylindrical battery cells 100 in a mixed series and parallel configuration.

[0041] The present invention further provides an electronic device, comprising an operating part and the above-mentioned battery assembly, and the operating part is electrically connected to the battery assembly to obtain electric energy for support. The operating part may be a unit part that can obtain electric energy from the battery assembly to perform corresponding work, such as a blade rotating part of an electric fan, a vacuum operating part of a vacuum cleaner, a wheel driving part of an electric vehicle, etc. The electronic device includes a vehicle, a mobile phone, a portable device, a laptop, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle may be a fuel vehicle, a gasoline vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a vehicle with extended range, etc. The spacecraft includes an aircraft, a rocket, a space shuttle, a spacecraft, etc. The electric toy includes a stationary or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, an electric plane toy, etc. The electric tool includes a metal cutting electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, a planer, etc., a grinding electric tool, an assembly electric tool, and a railway electric tool. The embodiment of the present invention is not particularly limited to the electronic device described above.

[0042] In the cylindrical battery cell 100 of the present invention, the positioning portion 140 is disposed on the housing connection portion 133 and / or the connection arm 134, and can exert a radial positioning function in the pressing process of the housing connection portion 133, thereby enabling accurate control of the amount of displacement in the radial direction, and enabling accurate positioning and connection of the housing connection portion 133 in the radial direction of the roll groove 113 to be realized. In this way, the stability of the welding area between the housing connection portion 133 and the roll groove 113 is improved, and the stability of the current carrying capacity of the entire cylindrical battery cell 100 is improved. At the same time, since the positioning portion 140 is disposed as a flat plate structure, the flat plate structure comes into line contact with the inner side wall 1132 of the roll groove 113 in the pressing process of the housing connection portion 133, thereby reducing the sliding resistance between the positioning portion 140 and the inner side wall 1132 of the roll groove 113, and thus reducing the possibility of damage to the positioning portion 140 or the inner side wall 1132 of the roll groove 113 in the pressing process. Therefore, the positioning accuracy of the roll groove 113 in the radial direction by the positioning part 140 of the housing 110 can be improved. Therefore, the present invention effectively overcomes some practical problems in the related art and has high utility value and significance. The above-mentioned embodiments are merely examples for explaining the principles and effects of the present invention, and are not intended to limit the present invention. Anyone with ordinary knowledge in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by a person with ordinary knowledge in the art without departing from the spirit and technical ideas disclosed in the present invention are still within the scope of the claims of the present invention. [Industrial Applicability]

[0043] The present invention provides a cylindrical battery cell with stable performance. [Explanation of symbols]

[0044] 100: Cylindrical battery cells 110: Housing 111: End wall 112: Side wall 113: Roll groove 1131: Welding mask 1132: Inner wall 114: Opening 120: Electrode assembly 121: First tab 130: Current collector 131: Welding Mask 132: Tab connection 133: Housing connection part 1331: Welding marks 134: Connecting arm 1341: Curved section 135: Exhaust vent 1351: Notch 136: Hollow area 140: Positioning part 150: Seal ring 151: Avoidance structure 160: End cap

Claims

1. A housing including an opening, the opening having a side wall formed with a roll groove; an electrode assembly, the electrode assembly being sealed and disposed within the housing, the roll groove restricting axial movement of the electrode assembly, and a first tab being provided on one side of the electrode assembly facing the opening; a current collector disposed within the housing, the current collector including a housing connection portion, a tab connection portion, and a connection arm, the housing connection portion being connected to the tab connection portion via the connection arm, the housing connection portion being connected to one side of the roll groove away from the electrode assembly, and the tab connection portion being connected to the first tab; Equipped with a positioning portion is provided on the housing connection portion and / or the connection arm, and the positioning portion is provided so as to restrict radial displacement of the housing connection portion; Cylindrical battery cell.

2. the current collector further includes a plate body, the housing connection portion and the plate body are connected via the connection arm, the housing connection portion extends along a circumferential direction of the housing, the positioning portion is formed by the housing connection portion extending toward the electrode assembly along a height direction of the housing, and the positioning portion abuts against an inner side wall of the roll groove; 2. The cylindrical battery cell according to claim 1.

3. At least two of the positioning portions are disposed on the housing connection portion, and the at least two positioning portions are disposed on both sides of the connection arm.

3. The cylindrical battery cell according to claim 2.

4. The positioning portion is formed by the connection arm extending toward the electrode assembly along a height direction of the housing, and the positioning portion abuts against an inner wall of the roll groove.

2. The cylindrical battery cell according to claim 1.

5. An obtuse angle is formed between the positioning portion and the housing connection portion.

5. A cylindrical battery cell according to claim 1 .

6. The connecting arm is provided with a stress buffer structure; 6. The cylindrical battery cell according to claim 5.

7. the connecting arm, the housing connecting portion and the plate body are integrally formed, the connecting arm includes a plurality of curved portions, and the curved portions are deformed when pressed; 7. The cylindrical battery cell according to claim 6.

8. The connection arm and the housing connection portion are independent components, and the connection arm is made of a flexible material.

7. The cylindrical battery cell according to claim 6.

9. a seal ring is disposed on one side of the roll groove away from the electrode assembly, and an avoidance structure is provided on an end face of the seal ring facing the housing connection part; 2. The cylindrical battery cell according to claim 1.

10. The avoidance structure is an annular groove structure, and the housing connection portion is accommodated in the annular groove structure.

10. The cylindrical battery cell according to claim 9.

11. the connecting arm is disposed between adjacent tab connection portions, and the connecting arm and the tab connection portion are partially separated; 2. The cylindrical battery cell according to claim 1.

12. An exhaust hole is provided at the center of the current collector, and a notch is provided along the periphery of the exhaust hole.

2. The cylindrical battery cell according to claim 1.

13. A battery assembly comprising the cylindrical battery cell according to claim 1.

14. An electronic device comprising the battery assembly according to claim 13.

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