Secondary battery and electric device including the secondary battery

Abstract

PURPOSE: To provide a secondary battery enabling solving of an issue of welding between an electrode pole and a power collection portion of an existing secondary battery, and an electric device including the secondary battery.SOLUTION: A secondary battery includes a housing, an electrode assembly, an electrode pole, and a power collection portion. The electrode assembly is disposed in the housing in an encapsulated state. The electrode pole is installed while passing through the housing and encapsulated and insulated, and a thinned region having thickness T1 is disposed. The power collection portion is disposed in the housing and electrically connected with an electrode of the electrode assembly. A welded portion having thickness T2 is disposed on the power collection portion, and T2 is greater than 0.3 T1. The thinned region is conducted in contact with the weld portion and fixed by welding.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to the field of battery technology, and in particular to secondary batteries and electrical devices including such secondary batteries. [Background technology]

[0002] One of the main methods for electrically connecting and fixing the positive electrode pole and current collector of a cylindrical battery is to use torque welding, and the other is to use laser welding (seam welding or full penetration welding).

[0003] Torque welding requires the insertion of a welding pin through the center hole of the electrode sheet assembly. The small center hole (5mm to 8mm) and large diameter of the welding pin typically require high positioning accuracy, resulting in low production efficiency and susceptibility to damage to the electrode sheet assembly. Torque welding, however, lacks an effective method for separating and suctioning the metal shavings generated during the welding process, resulting in the metal shavings remaining inside the secondary battery, posing a safety risk to the secondary battery. This also limits the welding area and current capacity for torque welding. Furthermore, the lack of an effective means for detecting and identifying the internal welding effect makes it impossible to determine the quality of the welding effect. Summary of the Invention [Problem to be solved by the invention]

[0004] Among laser welding methods, seam welding generally limits the strength and current-carrying capacity due to the small size of the electrode post area. Meanwhile, when the post integrated into the current collector passes through the electrode post through-hole, the required precision is affected by the precision of the electrode assembly inserted into the housing, making the construction difficult and significantly affecting production efficiency. Furthermore, metal shavings generated from scratches during the drilling process remain inside the secondary battery, posing a safety risk to the secondary battery. [Means for solving the problem]

[0005] In consideration of the above-mentioned drawbacks of the prior art, the present invention provides a secondary battery and an electric device including the secondary battery that can solve the welding problem that occurs when welding the pole and current collector of an existing secondary battery.

[0006] To achieve the above and other related objects, a first aspect of the present invention provides a secondary battery including a housing, an electrode assembly, a pole, and a current collector. The electrode assembly is hermetically disposed within the housing. The pole penetrates the housing in a sealed and insulated state, and a thinned region having a thickness T1 is disposed therein. The current collector is disposed within the housing and electrically connected to an electrode of the electrode assembly. A weld having a thickness T2 is disposed on the current collector, where T2 is greater than 0.3T1. The thinned region is in conductive contact with the weld and is fixed by welding.

[0007] In one example of the secondary battery of the present invention, the weld mark is located on the wall away from the weld in the thinned region.

[0008] In one example of the secondary battery of the present invention, the weld mark is annular.

[0009] In one example of the secondary battery of the present invention, a welding positioning structure is disposed in the thinned region.

[0010] In one example of the secondary battery of the present invention, the thinned area is circular, and the welding positioning structure is located at the center of the circle.

[0011] In one example of the secondary battery of the present invention, a reinforcing structure is disposed in the thinned region.

[0012] In one example of the secondary battery of the present invention, the reinforcing structure includes a first protrusion, and the first protrusion is disposed on one or both sides of the thinned region along the penetration direction of the electrode post.

[0013] In one example of the secondary battery of the present invention, the reinforcing structure includes a truncated cone disposed in the thinned region, the large end of the truncated cone being connected to the thinned region, and the welded region of the thinned region being disposed surrounding the truncated cone.

[0014] In one example of the secondary battery of the present invention, the truncated cone is disposed on one side of the thinned region away from the electrode assembly, and a welding positioning structure is disposed at the center of the small end face of the truncated cone.

[0015] In one example of the secondary battery of the present invention, the reinforcing structure and the thinned region are an integral structure.

[0016] In one example of the secondary battery of the present invention, the thickness T1 of the thinned region is 0.1 mm to 2 mm, and the thickness T2 of the welded portion is 0.1 mm to 3 mm. The thickness T2 of the welded portion is equal to or greater than the thickness T1 of the thinned region.

[0017] In one example of the secondary battery of the present invention, the housing is a cylinder with one closed end and the other open end, and the mounting holes for the poles are arranged in the wall of the closed end of the housing, and the poles are inserted into the mounting holes in a sealed and insulated state.

[0018] In one example of the secondary battery of the present invention, the pole includes a conductive member, a first fixing portion, and a second fixing portion, the conductive member penetrates the mounting hole of the pole, and the first fixing portion and the second fixing portion are respectively disposed at the outer end and inner end of the conductive member and sandwiched between the outer and inner sides of the closed end wall, respectively.

[0019] In one example of the secondary battery of the present invention, the protrusions of the first fixing portion and the second fixing portion cover at least the protrusion of the mounting hole of the electrode post along the penetrating direction of the electrode post.

[0020] In one example of the secondary battery of the present invention, an insulating member is disposed between the first fixing portion and the housing, and an insulating reinforcing structure for increasing the creepage distance is disposed on the insulating member.

[0021] In one example of the secondary battery of the present invention, the insulating member is made of transparent or translucent plastic.

[0022] In one example of the secondary battery of the present invention, the insulating reinforcing structure includes a chamfer or an arc disposed on the upper and / or lower side of the side wall of the insulating member.

[0023] In one example of the secondary battery of the present invention, the central portion of the end face of the pole on the side facing away from the electrode assembly and / or the central portion of the end face of the pole facing the electrode assembly is recessed to form a thinned region.

[0024] In one example of the secondary battery of the present invention, the thinned region includes a first plane and a second plane arranged in parallel, the first plane being formed by a recess in the center of the end face of the pole away from the electrode assembly, and the second plane being formed by a recess in the center of the end face of the pole closer to the electrode assembly.

[0025] In one example of the secondary battery of the present invention, a guide structure is disposed on the electrode post and / or the current collector to guide the welded portion into contact with the thinned region.

[0026] In one example of the secondary battery of the present invention, the guide structure includes one or a combination of a rounded corner shape, a chamfered shape, or a beveled shape.

[0027] In one example of the secondary battery of the present invention, an escape groove is disposed in the thinned region and / or on the current collector.

[0028] In one example of the secondary battery of the present invention, the welded portion is a second protrusion disposed on the current collector, and the second protrusion is welded and fixed to the thinned region.

[0029] In one example of the secondary battery of the present invention, the current collector includes a ring-shaped current collector body, the second protrusion is arranged at the center of the current collector body, the thickness of the second protrusion is greater than the thickness of the current collector body, and the thickness of the second protrusion is 0.3 mm to 3 mm.

[0030] In one example of the secondary battery of the present invention, a groove is disposed on the current collector.

[0031] In one example of the secondary battery of the present invention, a sinking platform is disposed on the top of the pole, and a protrusion of the sinking platform along the penetrating direction of the pole covers at least the thinned region.

[0032] In one example of the secondary battery of the present invention, the recessed platform has an inverted trapezoidal structure, and the depth of the recessed platform along the direction in which the electrode post penetrates is 0.1 mm to 1.5 mm.

[0033] In one example of the secondary battery of the present invention, the secondary battery further includes a pole cover, the shape of which matches the concave platform, and the pole cover is placed on the concave platform and fixed to the pole by conductive welding.

[0034] In one example of the secondary battery of the present invention, a welding positioning structure is disposed on the pole cover.

[0035] In one example of the secondary battery of the present invention, the welding positioning structure is any one of a tapered hole, a cylindrical hole, or a hemispherical hole.

[0036] In one example of the secondary battery of the present invention, a third protrusion is disposed on one side of the pole cover facing the thinned region, and the projection of the third protrusion along the penetrating direction of the pole covers at least the thinned region.

[0037] In one example of the secondary battery of the present invention, a first protrusion corresponding to the position of the third protrusion is arranged on one side of the thinned region facing the pole cover, and the first protrusion is configured to abut against the third protrusion when the external force received by the pole cover exceeds a set threshold.

[0038] In one example of the secondary battery of the present invention, the gap between the first protrusion and the third protrusion is 0.05 mm to 0.5 mm.

[0039] In one example of the secondary battery of the present invention, the pole cover includes a third fixing portion and an outer weld portion, and the thickness of the outer weld portion is greater than the thickness of the third fixing portion.

[0040] In one example of the secondary battery of the present invention, the external welded portion is higher than the third fixing portion, and the height difference is 0.05 mm to 1 mm.

[0041] A second aspect of the present invention provides an electric device including a working unit and the secondary battery according to any one of the above-described embodiments, wherein the working unit is electrically connected to the secondary battery to obtain electric energy for support. [Effects of the Invention]

[0042] The secondary battery of the present invention has a thinned region on the electrode post and a weld on the current collector, and the thinned region is electrically connected to the weld. This eliminates the need to insert a welding device inside the secondary battery housing, allowing the current collector and thinned region to be welded outside the housing. This not only improves production efficiency, but also reduces the requirements for process positioning accuracy and avoids metal shavings generated inside the secondary battery during the welding process between the electrode post and the current collector, thereby improving the reliability and safety of the secondary battery. At the same time, the secondary battery of the present invention also limits the thickness of the thinned region and weld region, thereby not only solving the problems of false welding or welding penetration, but also achieving better welding results and improving electrical connection strength and current-carrying capacity. At the same time, the welds of this type of secondary battery are located outside the housing, making them easy to detect and identify, helping to ensure consistency in production and manufacturing. An electrical device of the present invention includes a secondary battery of the present invention and has high reliability in supplying electrical energy. [Brief explanation of the drawings]

[0043] In order to more clearly describe the embodiments of the present invention or the technical solutions of the prior art, the drawings that need to be used in the description of the embodiments or the prior 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 any creative efforts.

[0044] [Figure 1] 1 is a three-dimensional schematic view of one embodiment of a secondary battery of the present invention. [Figure 2] 1 is a three-dimensional schematic view of one embodiment of a secondary battery of the present invention after removing the housing. FIG. [Figure 3] 1 is a three-dimensional cross-sectional view of one embodiment of a secondary battery of the present invention. [Figure 4] FIG. 4 is a partial enlarged view of region I in FIG. 3. [Figure 5] 1 is a schematic diagram showing the configuration of a portion of a pole on a housing in one embodiment of a secondary battery of the present invention. [Figure 6] 1 is a schematic diagram showing the configuration of a portion of a pole on a housing in one embodiment of a secondary battery of the present invention. [Figure 7] 1 is a schematic diagram showing the configuration of a portion of a pole on a housing in one embodiment of a secondary battery of the present invention. [Figure 8] 1 is a schematic diagram showing the configuration of a portion of a pole on a housing in one embodiment of a secondary battery of the present invention. [Figure 9] 1 is a schematic diagram showing the configuration of a portion of a pole on a housing in one embodiment of a secondary battery of the present invention. [Figure 10] 1 is a schematic diagram showing the configuration of a portion of a pole on a housing in one embodiment of a secondary battery of the present invention. [Figure 11] 1 is a three-dimensional view of the pole side of one embodiment of a secondary battery of the present invention. [Figure 12] 1 is an exploded view of a pole cover and a pole in one embodiment of a secondary battery of the present invention. [Figure 13] 1 is a top view of the electrode post side of one embodiment of a secondary battery of the present invention. [Figure 14] FIG. 2 is a top view of the electrode post side of one embodiment of the secondary battery of the present invention after removing the electrode post cover. [Figure 15] 1 is a three-dimensional structural view of a current collecting part seen from the pole side in one embodiment of a secondary battery of the present invention. [Figure 16] 1 is a three-dimensional structural view of a current collecting part seen from the electrode assembly side in one embodiment of a secondary battery of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0045] Hereinafter, the present invention will be described in detail with reference to specific examples. However, those skilled in the art will readily understand other advantages and effects of the present invention from the disclosure herein. The present invention can also be implemented or applied through other different specific implementations. The details in this specification can be modified or changed in various ways based on different perspectives and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments may be combined with each other if there is no contradiction between the embodiments. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific implementations and do not limit the scope of protection of the present invention. In the following examples, for test methods for which specific conditions are not specified, conventional conditions or conditions suggested by each manufacturer should generally be followed.

[0046] Where an embodiment provides a range of values, it should be understood that the two endpoints of each range and any value between the two endpoints can be selected unless otherwise specified in the present invention. word, Knowledge of the prior art and description of the invention by one skilled in the art Based on this, the present invention The method described in the embodiment of the present invention The present invention may also be practiced using any methods, devices, and materials similar or equivalent to those described above.

[0047] It should be noted that terms such as "upper," "lower," "left," "right," "middle," and "first" used in this specification are for the convenience of explanation and are not used to limit the scope of this specification. Regarding the feasible scope of the present invention, changes and adjustments of relative relationships should also be considered within the feasible scope of the present invention as long as there is no substantial change in the technical content.

[0048] Please refer to Figures 1 to 16. The present invention provides a secondary battery 100 and an electric device including the secondary battery 100. The structure of the secondary battery 100 not only allows a welding device to weld the current collecting portion 140 and the thinned region 131 outside the housing 110, but also solves the problem of false welding or welding penetration and achieves a better welding effect.

[0049] 2 to 5, the secondary battery 100 includes a housing 110, an electrode assembly 120, a pole 130, and a current collector 140. The housing 110 is arranged to form an internal space for accommodating the electrode assembly 120, and the internal space formed by the housing 110 can be used to accommodate the electrode assembly 120, an electrolyte (not shown), and other components. The housing 110 can have various shapes and sizes, such as a cylinder, a rectangular parallelepiped, or a hexagonal prism. Specifically, the shape of the housing 110 can be determined depending on the specific shape and size of the electrode assembly 120. The housing 110 can be made of various materials, such as copper, iron, aluminum, stainless steel, or an aluminum alloy.

[0050] See Figures 2 and 3. In one example of the secondary battery 100 of the present invention, the housing 110 is a cylinder with one closed end and the other open end. An end cap 160 seals the opening of the cylinder. In one embodiment, the pole 130 is electrically connected to the positive tab of the electrode assembly 120 via the current collector 140, and the housing 110 is electrically connected, directly or indirectly (through another current collector), to the negative tab of the electrode assembly 120. The entire housing 110 is negatively charged. The positive pole and the end face of the housing are both located on the same side where the pole 130 is located, so that the positive and negative electrodes are on the same side. In this way, the pole 130 and the end cap 160 constitute the positive and negative electrodes of the secondary battery 100, respectively. The mounting holes for the pole 130 are located on the end wall 111 at the closed end of the housing 110, and the pole 130 is placed in the mounting holes in a sealed and insulated manner. This structure of the housing 110 can improve construction efficiency and has better assembly and sealing performance than a housing 110 having openings on both ends.

[0051] 2 to 5, the electrode assembly 120 is disposed in the housing 110 in a sealed state, and the specific form of sealing is not limited. The electrode assembly 120 is a component in the secondary battery 100 where an electrochemical reaction occurs. One or more electrode assemblies 120 may be housed in the housing 110. The electrode assembly 120 is mainly formed by winding or stacking 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 portions of the positive electrode sheet and the negative electrode sheet that contain active material constitute the main body of the electrode assembly 120, and the portions of the positive electrode sheet and the negative electrode sheet that do not contain active material constitute tabs (not shown).

[0052] As long as the electrode post 130 is sealed and insulated from the housing 110, the method of arranging the electrode post 130 on the housing 110 is not limited. See FIGS. 5 and 6. In this embodiment, the electrode post 130 is installed through the housing in a sealed and insulated state, and a thinned region 131 with a thickness T1 is disposed on the electrode post 130. The thinned region 131 has a surface that can be exposed to the outside of the housing 110. The shape of the thinned region 131 is not limited, and may be, for example, rectangular, annular, circular, or a special shape as long as the shape of the thinned region 131 has a sufficient welding area to meet the requirements for external welding. The current collecting portion 140 is disposed within the housing 110 and is located between the electrode assembly 120 and the end wall 111 of the housing 110. One side of the current collecting portion 140 away from the end wall 111 is electrically connected to the electrode (tab) of the electrode assembly 120. One side of the current collecting portion 140 facing the end wall 111 is covered with an insulating film 150. The insulating film 150 is arranged to insulate and separate the current collecting portion 140 from the end wall 111 of the housing 110. A weld portion 141 having a thickness T2 is arranged on the current collecting portion 140, where T2 is greater than 0.3T1. The weld portion 141 passes through a through hole in the insulating film 150, makes conductive contact with the thinned region 131, and is fixed by welding. The shape of the contact surface for conductive contact is not limited, and may be, for example, rectangular, circular, annular, or a special shape as long as the shape of the contact surface can meet the stable current transmission requirements. In addition, the welding method is not limited as long as the welding method can weld the thinned region 131 and the weld portion 141 outside the housing 110. When T2 is less than 0.3T1, i.e., when the thickness T1 of the thinned region significantly exceeds the thickness T2 of the weld 141, welding from the outside of the pole 130 must pass through the thicker thickness T1. In this situation, high-energy laser welding is required, but controlling the laser energy is difficult. If the laser energy is not properly controlled, weld penetration is likely to occur, which could result in pole leakage. Insufficient laser energy will result in false welding. Therefore, properly controlling the thickness relationship helps control the weld depth and avoid weld penetration.Therefore, the present invention can ensure the welding requirements by limiting the thickness of the thinned area 131 and the welded area 141, prevent excessive heat from being transferred to the electrode assembly 120, and solve the problems of false welding and weld penetration caused by the mismatch in thickness between the thinned area 131 and the welded area 141.

[0053] In one example of the secondary battery 100 of the present invention, a weld mark (not shown) is disposed on the wall of the thinned region 131 away from the welded portion 141. The weld mark is formed by using a laser. penetration The shape of the weld mark corresponds to the laser welding trajectory of the welding equipment and is not limited to a ring shape.

[0054] See Figures 5 and 6. In one example of the secondary battery 100 of the present invention, a first welding positioning structure 1321 is disposed on the thinned region 131. The first welding positioning structure 1321 is disposed for accurate visualization and identification for positioning the welding region during welding. The shape and structure of the first welding positioning structure 1321 are not limited as long as accurate visualization and identification for positioning the welding region are possible and an external welding device is applicable. For example, the shape and structure of the first welding positioning structure 1321 may be any one of a tapered hole, a cylindrical hole, or a hemispherical hole.

[0055] 12 and 14. Considering the shape of the welding head of the laser welding device in the welding process of the pole post 130, in one example of the secondary battery 100 of the present invention, the housing 110 is cylindrical, the pole post 130 also has a rotational structure, and preferably the thinned region 131 is circular, the first welding positioning structure 1321 is disposed at the center of the circle, the first welding positioning structure 1321 is a first hemispherical hole, and the rotation axis of the first hemispherical hole (i.e., the axis perpendicular to the end face of the hemisphere and passing through the center of the sphere) is coaxial with the circular thinned region 131.

[0056] See FIGS. 5 and 6. In one example of the secondary battery 100 of the present invention, a reinforcing structure is disposed in the thinned region 131. The shape of the reinforcing structure is not limited as long as it can reinforce the thinned region 131 without affecting the welding. In one example of the secondary battery 100 of the present invention, the reinforcing structure includes a first protrusion 132, which is disposed on one or both sides of the thinned region 131 along the penetration direction of the electrode post 130. The first protrusion 132 prevents deformation of the welded portion 141 during the construction of the electrode post 130 or the press-fitting process of the current collector 140 from affecting the welding effect. It should be noted that if the first protrusions 132 are distributed on both sides of the thinned region 131, corresponding grooves should be disposed in the welded portion 141 of the current collector 140 to avoid interference with the first protrusions 132 facing one side of the current collector 140.

[0057] See Figures 5 and 6. In one example of the secondary battery 100 of the present invention, the reinforcing structure and the thinned region 131 are connected by welding, bonding, or integral molding, but the present invention is not limited thereto. The reinforcing structure includes a truncated cone disposed in the thinned region 131. The truncated cone has a small circular end face (hereinafter referred to as the "small end") and a large circular end face (hereinafter referred to as the "large end"). The large end of the truncated cone contacts the top surface of the thinned region 131 and is welded or integrally connected to the thinned region 131. The connection between the large end and the thinned region 131 can improve connection stability and provide a better reinforcement effect compared to a cone shape. The welded region of the thinned region 131 and the current collecting part 140 is disposed around the truncated cone to form an annular welded region, and an annular weld mark is formed on the outer surface of the annular welded region of the thinned region 131.

[0058] See Figures 5 and 6. In the present invention, the weld reinforcement structure and the first weld positioning structure 1321 may be installed independently and separately, or may be combined with each other to form a reinforcement and positioning combination. In one example of the secondary battery 100 of the present invention, the truncated cone is disposed on one side of the thinned region 131 away from the electrode assembly 120, and the first weld positioning structure 1321 is disposed at the center of the small end face of the truncated cone. Such a reinforcement structure and the first weld positioning structure 1321 complement each other, simplifying the structure and reducing the area occupied on the surface of the electrode post 130. At the same time, the coaxial arrangement of the annular weld region and the first weld positioning structure 1321 helps to accurately position the welding equipment.

[0059] Considering the penetration capabilities and parameters of existing penetration laser welding equipment, preferably, in one example of the secondary battery 100 of the present invention, the thickness T1 of the thinned region 131 is 0.1 mm to 2 mm, and the thickness T2 of the welded portion 141 is 0.1 mm to 3 mm. The thickness T2 of the welded portion 141 is greater than or equal to the thickness T1 of the thinned region 131. In this way, it is possible to better prevent the welded portion 141 from penetrating and causing leakage of the electrode post 130 when a large amount of laser is used for welding, and also to avoid an increase in the cost and weight of the secondary battery 100.

[0060] See FIG. 6. In one example of the secondary battery 100 of the present invention, the pole 130 includes a conductive member 134, a first fixing portion 135, and a second fixing portion 136. The conductive member 134 has a cylindrical structure. The conductive member 134 is disposed in a mounting hole of the pole 130. The first fixing portion 135 is disposed circumferentially on the outer end (the end away from the electrode assembly 120) of the conductive member 134 and is sandwiched between the outer side of the closed end wall 111 (the side away from the electrode assembly 120). The second fixing portion 136 is disposed circumferentially on the inner end (the end facing the electrode assembly 120) of the conductive member 134 and is sandwiched between the inner side of the closed end wall 111 (the side facing the electrode assembly 120). In one example of the secondary battery 100 of the present invention, the projections of the first fixing portion 135 and the second fixing portion 136 along the penetration direction of the pole 130 at least cover the projections of the mounting holes of the pole 130. In this way, on the one hand, the structural stability of the pole 130 can be improved, and on the other hand, the relatively large first fixing portion 135 and / or second fixing portion 136 can press-fit the insulating or sealing member 139, so that the pole 130 and the mounting hole of the pole 130 can be sealed and insulated from each other while the pole 130 is inserted.

[0061] See FIGS. 6 and 10. In one example of the secondary battery 100 of the present invention, the poles 130 achieve insulation and separation through the first insulating member 137, the second insulating member 138, and the end wall 111, respectively, and the mounting holes of the poles 130 are sealed by press-fitting a seal member 139 through the first fixing portion 135. The first insulating member 137 is disposed between the first fixing portion 135 and the outer wall of the closed end of the housing 110. An insulating reinforcement structure for increasing the creepage distance is disposed on the first insulating member 137. The insulating reinforcement structure may be, for example, a structure that can increase the conductive path between the housing 110 and the first fixing portion 135 by changing the straight path on the conductive path between the housing 110 and the first fixing portion 135 into a curve or multiple polylines. Considering the need for creepage reinforcement and cost, the insulating reinforcement structure may include, for example, a chamfer or a circular arc disposed on the upper and / or lower side of the side wall of the insulating member. In this embodiment, the insulating reinforcement structure includes a first chamfer 1371 disposed between the outer wall of the insulating member and the contact surface between the insulating member and the housing 110, and may further include a first chamfer 1371 disposed on the upper part of the upper fixing portion. The type of chamfer may include, but is not limited to, a straight chamfer or a circular chamfer. In another embodiment, the insulating reinforcement structure includes a chamfer disposed between the upper end of the insulating member and the side wall of the insulating member. In yet another embodiment of the present invention, the insulating reinforcement structure includes a chamfer disposed between the upper end of the insulating member and the side wall of the insulating member, and at the same time, a chamfer disposed between the outer wall of the insulating member and the contact surface between the insulating member and the housing 110.

[0062] When connecting multiple secondary batteries 100 in series or parallel to form a battery module or battery pack, the outer surface of the secondary battery may be laser cleaned to ensure reliable welding when connecting an external battery. In one example of the secondary battery 100 of the present invention, the first insulating member 137 is made of transparent or translucent plastic, for example, PFA, PP, PBT, or PPS. This prevents the insulating seal from failing due to heat absorption and burnout that occurs with conventional plastic parts made of black or other opaque materials.

[0063] See FIG. 6 . In one example of the secondary battery 100 of the present invention, the central portion of the end surface of the electrode post 130 on the side facing away from the electrode assembly 120 and / or the central portion of the end surface of the electrode post 130 facing the electrode assembly 120 is recessed to form a thinned region 131. It should be noted that the thinned region 131 may be formed simply by a recess in the central portion of the end surface of the electrode post 130 on the side facing away from the electrode assembly 120 or a recess in the central portion of the end surface of the electrode post 130 facing the electrode assembly 120, or may be formed by a recess in both the central portion of the end surface of the electrode post 130 on the side facing away from the electrode assembly 120 and the central portion of the end surface of the electrode post 130 facing the electrode assembly 120. In one example of the secondary battery 100 of the present invention, the thinned region 131 includes a first plane 1311 and a second plane 1312 arranged in parallel. The first plane 1311 is formed by a recess in the center of the end face of the pole post 130 on one side facing away from the electrode assembly 120, and the second plane 1312 is formed by the center of the end face of the pole post 130 closer to the electrode assembly 120, so that the whole forms an "H"-shaped structure, and the thinned region 131 is located at the horizontal connecting portion of the "H" structure. On the one hand, the parallel first plane 1311 and second plane 1312 can make the wall thickness of the thinned region 131 uniform, and on the other hand, these planes can facilitate welding.

[0064] See FIGS. 6 and 12. In one example of the secondary battery 100 of the present invention, the welded portion 141 is a second protrusion 1413 disposed on the current collector 140. The upper end surface of the second protrusion 1413 and the thinned region 131 are fixed by welding. The shape of the second protrusion 1413 is not limited as long as the second protrusion 1413 can be reliably in contact with the thinned region 131 and welded thereto. For example, the cross section of the second protrusion 1413 may be circular, rectangular, or the like. Preferably, in one example of the secondary battery 100 of the present invention, the current collector 140 includes an annular current collector body 142, and the second protrusion 1413 is a cylindrical boss. The second protrusion 1413 is disposed at the center of the current collector body 142 and is coaxial with the current collector body 142. The thickness of the second protrusion 1413 is greater than that of the current collector body 142, and the thickness of the second protrusion 1413 is 0.3 mm to 3 mm. On the one hand, this arrangement allows the thickness of the weld at the welded portion 141 to be thicker, which prevents the electrode assembly 120 from being damaged by the weld penetration or welding heat. On the other hand, the thickness of the current collector body 142 can be made thinner, which allows the current collector body 142 and the tab of the electrode assembly 120 to be thinner. penetration Welding can be easily achieved.

[0065] See FIG. 6 . In one example of the secondary battery 100 of the present invention, a guide structure is disposed on the electrode post 130 and / or the current collector 140 to guide the weld 141 into contact with the thinned region 131. The guide structure serves to introduce the weld 141 of the current collector 140 into a position below the thinned region 131. It should be noted that the guide structure may be disposed only on the weld 141, or only on the thinned region 131, or the guide structure may be disposed both on the weld 141 and in the thinned region 131 to simultaneously or sequentially guide the weld 141 into contact with the thinned region 131. The guide structure includes one or a combination of a rounded corner shape, a chamfered shape, and a beveled shape. In this example, the thinned region 131 is annular, the welded portion 141 is circular or annular, and the guide structure includes a first tapered surface 1361 disposed at an opening in the side wall of the thinned region 131 and a second tapered surface 1412 disposed at an upper portion of the side wall of the second protrusion 1413. The large end of the first tapered surface 1361 faces one side of the electrode assembly 120, and the small end of the first tapered surface 1361 faces the opposite side from the electrode assembly 120. The large end of the second tapered surface 1412 faces one side of the electrode assembly 120, and the small end of the second tapered surface 1412 faces the opposite side from the electrode assembly 120.

[0066] In one example of the secondary battery 100 of the present invention, a relief groove is disposed in the thinned region 131 and / or on the current collecting portion 140. This configuration prevents local deformation in the welding region where the thinned region 131 is welded to the welded portion 141 from affecting the bond. It should be noted that the location of the relief groove is not limited as long as the relief groove is disposed in the contact region where the thinned region 131 and the welded portion 141 come into contact with each other to reduce the contact area between them. For example, as shown in FIG. 9 , a first relief groove 1411 may be disposed only on the welded portion 141, or as shown in FIG. 8 , a second relief groove 1313 may be disposed only on the underside of the thinned region 131. Alternatively, the first relief groove 1411 may be disposed on the welded portion 141, and the second relief groove 1313 may be disposed on the underside of the thinned region 131. The shape and depth of the relief groove are not limited. For example, the shape may be circular, rectangular, annular, or the like. Preferably, in this embodiment, the thinned region 131 is circular, the second boss is circular, and the relief groove is also preferably circular and is arranged coaxially with the first boss and the thinned region 131, so that a uniform annular welding region can be formed around the relief groove to avoid deformation caused by uneven welding stress.

[0067] 15 and 16 , in one example of a secondary battery 100 of the present invention, a second groove 1414 is arranged on one side of the current collector 140 facing the electrode assembly 120. The second groove 1414 can reduce damage to the electrode assembly 120 caused by heat effects during the welding process. Preferably, the second groove 1414 is arranged on the lower surface of the welded portion 141, and the protrusion along the penetration direction of the electrode post 130 covers the welded area of ​​the welded portion 141. This arrangement can prevent the welded area from coming into direct contact with the electrode assembly 120, thereby reducing damage to the electrode assembly 120 caused by heat effects during the welding process.

[0068] See FIGS. 6 and 12. In one example of the secondary battery 100 of the present invention, a recessed platform 1351 is disposed on top of the electrode post 130. The protruding portion of the recessed platform 1351 along the penetration direction of the electrode post 130 covers at least the thinned region 131. The shape of the recessed platform 1351 is not limited and may be, for example, rectangular or circular. Preferably, in one example of the secondary battery 100 of the present invention, the sidewall of the recessed platform 1351 has a rotated structure having an inverted trapezoidal structure. The depth H2 of the recessed platform 1351 along the penetration direction of the electrode post 130 is 0.1 mm to 1.5 mm. In one example of the secondary battery 100 of the present invention, the secondary battery 100 further includes a electrode post cover 133. The shape of the electrode post cover 133 matches the shape of the recessed platform 1351. The electrode post cover 133 is disposed on the recessed platform 1351 and fixed to the electrode post 130 by conductive welding. This configuration allows a large conductive end surface to be formed on the top of the electrode post 130, ensuring that the electrode post 130 of a single secondary battery has a large welding surface when multiple secondary batteries are connected in series or parallel. At the same time, the installation of the recessed platform 1351 prevents damage to the thinned region 131 during the welding process of the electrode post cover 133 and the recessed platform 1351. In one example of the secondary battery 100 of the present invention, a second welding positioning structure 1331 is disposed on the electrode post cover 133. The second welding positioning structure 1331 is any one of a tapered hole, a cylindrical hole, and a hemispherical hole.

[0069] See Figure 7. In one example of the secondary battery 100 of the present invention, a third protrusion 1334 is disposed on one side of the electrode post cover 133 facing the thinned region 131. The protruding portion of the third protrusion 1334 along the penetration direction of the electrode post 130 covers at least the thinned region 131. The third protrusion 1334 is accommodated in a cavity between the electrode post cover 133 and the thinned region 131. The provision of the third protrusion 1334 significantly improves the wall thickness and strength of the electrode post cover 133 and can prevent melting and penetration due to laser welding.

[0070] See Figure 7. In one example of the secondary battery 100 of the present invention, the first protrusion 132 is disposed on one side of the thinned region 131 facing the electrode post cover 133, corresponding to the position of the third protrusion 1334. The first protrusion 132 is configured to come into contact with the third protrusion 1334 when an external force received by the electrode post cover 133 exceeds a set threshold. In this way, the first protrusion 132 resists the third protrusion 1334 when a large external force is applied, thereby improving the overall structural strength of the electrode post 130 as a unit and ensuring structural reliability.

[0071] See Figure 7. As long as the first protrusion 132 can resist the third protrusion 1334 when the external force exceeds the set threshold, the gap between the first protrusion 132 and the third protrusion 1334 can be selected according to the set threshold of the external force. penetration Considering the pressing force during welding, in this embodiment, the gap H1 between the first protrusion 132 and the third protrusion 1334 is preferably 0.05 mm to 0.5 mm. When a large external force is applied, the first protrusion 132 and the third protrusion 1334 can resist each other, thereby improving the overall structural strength of the terminal post 130 as a unit and ensuring structural reliability.

[0072] See FIG. 8. The structural shape of the electrode post cover 133 is not limited as long as it can shield and protect the thinned region 131 and provide a larger external electrical connection surface. Preferably, in one example of the secondary battery 100 of the present invention, the electrode post cover 133 includes a third fixing portion 1332 and an external weld portion 1333. The third fixing portion 1332 is arranged to be welded and fixed to the first fixing portion 135, and the external weld portion 1333 is arranged for external electrical connection to another structure. The thickness of the external weld portion 1333 is greater than the thickness of the fixing portion. In one example of the secondary battery 100 of the present invention, the external weld portion 1333 is higher than the third fixing portion 1332, with a height difference H3 of 0.05 mm to 1 mm. Setting the height within this range can prevent impact on the external adapter member caused by the operation of welding the fixing portion to the protrusion.

[0073] A second aspect of the present invention further provides an electric device including a working unit and the secondary battery described in any one of the above embodiments, where the working unit is electrically connected to the secondary battery 100 to obtain supporting electric energy. The electric device may be a vehicle, a mobile phone, a portable device, a laptop, a boat, a spacecraft, an electric toy, a power tool, etc. The vehicle may be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a long-distance vehicle, etc. The spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc. The electric toys may include stationary or mobile electric toys, such as game consoles, electric toy cars, electric toy boats, and electric toy airplanes, etc. The power tools may 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, planers, etc. The embodiments of the present invention are not particularly limited to the above-mentioned electric devices.

[0074] In the secondary battery 100 of the present invention, the thinned region 131 is disposed on the electrode post 130, the welding portion 141 is disposed on the current collecting portion 140, and the thinned region 131 is in conductive contact with the welding portion 141. This eliminates the need to insert a welding device into the housing 110 of the secondary battery 100, and allows welding of the current collecting portion 140 and the thinned region 131 outside the housing 110. This not only improves production efficiency, but also reduces the requirements for process positioning accuracy and avoids metal shavings generated inside the secondary battery 100 during the welding process between the electrode post 130 and the current collecting portion, thereby improving the reliability and safety of the secondary battery 100. At the same time, the secondary battery 100 of the present invention further limits the thickness of the thinned region 131 and the welding portion 141, thereby not only solving the problem of false welding or weld penetration, but also achieving better welding effects and improving electrical connection strength and current-carrying capacity. At the same time, the welded portion 141 of this type of secondary battery 100 is located outside the housing 110, which facilitates detection and identification and helps ensure consistency in production and manufacturing. The electrical device of the present invention includes the secondary battery 100 of the present invention and has high reliability in supplying electrical energy. Therefore, the present invention effectively overcomes several practical problems in the prior art and has high utility value and practical significance. The above-described embodiments are merely examples for illustrating the principles and effects of the present invention and are not intended to limit the present invention. Those skilled in the art may modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, any equivalent modifications or variations made by those skilled in the art without departing from the spirit and scope of the present invention are intended to fall within the scope of protection of the present invention. [Industrial Applicability]

[0075] The secondary battery of the present invention and the electric device including the same can be applied to the field of new energy vehicles. [Explanation of symbols]

[0076] 100 Secondary battery 110 Housing 111 End Wall 120 Electrode Assembly 130 Pole Pillar 131 Thinning area 1311 1st plane 1312 2nd plane 1313 Second relief groove 132 First protrusion 1321 First welding positioning structure 133 Pole cover 1331 Second welding positioning structure 1332 Third fixed part 1333 External Welds 1334 Third protrusion 134 Conductive materials 135 1st fixed part 1351 Drilling Platform 1352 First rounded corner 136 Second fixed part 1361 First tapered surface 137 First insulating member 1371 First chamfer 138 Second insulating member 139 Sealing material 140 Current collector 141 Welded Section 1411 First relief groove 1412 Second tapered surface 1413 Second protrusion 1414 Second groove 142 Annular collector body 150 insulating film 160 End Cap

Claims

1. Housing and an electrode assembly hermetically disposed within the housing; a pole post disposed through the housing in a sealed and insulated state, the pole post having a thinned region with a thickness T1; a current collector disposed within the housing and electrically connected to an electrode of the electrode assembly; a welded portion having a thickness T2 is disposed on the current collecting portion, T2 being greater than 0.3T1, the thinned region is in conductive contact with the welded portion, and the welded portion is fixed by full penetration welding from the outer side of the pole; a concave platform is disposed on the top of the pole pillar, and a projection of the concave platform along the penetration direction of the pole pillar covers at least the thinned region; The recessed platform has an inverted trapezoidal structure, and the depth of the recessed platform along the penetration direction of the pole post is 0.1 mm to 1.5 mm. Secondary battery.

2. The secondary battery according to claim 1 , wherein a reinforcing structure is disposed so as to be surrounded by the thinned region.

3. The secondary battery according to claim 2 , wherein the reinforcing structure includes a first protrusion, the first protrusion being disposed on one or both sides of the thinned region along a penetration direction of the electrode post.

4. 3. The secondary battery according to claim 2, wherein the reinforcing structure includes a truncated cone disposed in the thinned region, a large end of the truncated cone connected to the thinned region, and a welding region between the thinned region and the current collector portion forming a welding region disposed surrounding the truncated cone.

5. 5. The secondary battery according to claim 4, wherein the truncated cone is disposed on one side of the thinned region away from the electrode assembly, and a welding positioning structure is disposed at the center of a small end face of the truncated cone.

6. 2. The secondary battery according to claim 1, wherein the thickness T1 of the thinned region is 0.1 mm to 2 mm, the thickness T2 of the weld is 0.1 mm to 3 mm, and the thickness T2 of the weld is equal to or greater than the thickness T1 of the thinned region.

7. 2. The secondary battery according to claim 1, wherein the housing is a cylinder with one closed end and the other open end, the mounting holes for the poles are arranged in the closed end wall of the housing, and the poles are inserted into the mounting holes in a sealed and insulated state.

8. 8. The secondary battery of claim 7, wherein the pole includes a conductive member, a first fixing portion, and a second fixing portion, the conductive member penetrates the mounting hole of the pole, the first fixing portion and the second fixing portion are disposed at the outer end and inner end of the conductive member, respectively, and are sandwiched between the outer and inner sides of the closed end wall, respectively.

9. The secondary battery according to claim 8 , wherein an insulating member is disposed between the first fixing portion and the housing, and the insulating member is made of transparent or translucent plastic.

10. The secondary battery according to claim 9 , further comprising an insulating reinforcing structure disposed on the insulating member for increasing a creepage distance.

11. 2. The secondary battery according to claim 1, wherein the thinned region includes a first plane and a second plane arranged in parallel, the first plane being formed by a recess in the center of an end face of the pole away from the electrode assembly, and the second plane being formed by a recess in the center of an end face of the pole closer to the electrode assembly.

12. 2. The secondary battery according to claim 1, wherein a guide structure is disposed on the electrode post and / or the current collector to guide the welded portion into contact with the thinned region, and the guide structure includes one or a combination of a rounded corner shape, a chamfered shape, or a beveled shape.

13. The secondary battery according to claim 1 , wherein a relief groove is disposed in the thinned region and / or on the current collector.

14. 2. The secondary battery according to claim 1, wherein the welded portion is a second protrusion disposed on the current collector, the second protrusion is welded and fixed to the thinned region, the current collector includes an annular current collector body, the second protrusion is disposed at the center of the current collector body, the thickness of the second protrusion is greater than the thickness of the current collector body, and the thickness of the second protrusion is 0.3 mm to 3 mm.

15. 2. The secondary battery according to claim 1, further comprising a pole cover, the shape of which matches the concave platform, the pole cover being placed on the concave platform and fixed to the pole by conductive welding.

16. 16. The secondary battery of claim 15, wherein a third protrusion is disposed on one side of the electrode post cover facing the thinned region, and a projection of the third protrusion along the penetration direction of the electrode post covers at least the thinned region.

17. 17. The secondary battery of claim 16, wherein a first protrusion corresponding to the position of the third protrusion is disposed on one side of the thinned region facing the electrode post cover, and the first protrusion is configured to abut against the third protrusion when an external force received by the electrode post cover is greater than a set threshold.

18. An electric device comprising a working part and the secondary battery according to any one of claims 1 to 17, wherein the working part is electrically connected to the secondary battery to obtain electric energy for support.

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