Secondary battery, battery pack, and electronic device

Abstract

The utility model provides a kind of secondary battery, battery pack and electronic device;The secondary battery includes: shell, cover plate, electrode assembly and current collecting member;Shell includes side wall, and side wall forms at least one opening;Cover plate blocks at least one opening;The end surface of electrode assembly facing cover plate includes center area and edge area around center area, and center area is protruded to cover plate side relative to edge area;Current collecting member is set between electrode assembly and cover plate, including first connecting part and second connecting part, first connecting part is at least partially welded with center area, second connecting part surrounds first connecting part, and cover plate, second connecting part and side wall are connected by welding mark;It further includes limiting structure, limiting structure surrounds center area, one end of limiting structure abuts first connecting part and / or second connecting part, other end abuts edge area, and it is insulated with edge area, and the technical problem of poor welding caused by the low assembly precision of current collecting member and shell and cover plate can be alleviated.

Description

Technical Field

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

[0002] The current collector is an important component of a secondary battery, serving as a key part connecting the electrode assembly and the casing. During battery assembly, the current collector is placed between the electrode assembly and the cover plate, connected to the electrode assembly via a first connecting part, and welded to the casing and / or cover plate via a second connecting part, thereby achieving electrical connection between the electrode assembly and the casing.

[0003] In some processing techniques, the current collector, shell, and cover plate are welded using top welding. However, it is difficult to ensure the assembly accuracy of the current collector, shell, and cover plate, which can lead to defects such as weld spatter, collapse, and weld failure, thus reducing the welding quality. Utility Model Content

[0004] This utility model provides a secondary battery, a battery pack, and an electronic device to alleviate the technical problem of poor welding caused by low assembly precision of the current collector, the housing, and the cover plate.

[0005] This utility model provides a secondary battery, which includes: a shell, a cover plate, an electrode assembly, and a current collector; the shell includes a sidewall, and the sidewall forms at least one opening in the circumferential direction; the cover plate seals at least one opening; the electrode assembly is housed in the shell, and the end face of the electrode assembly facing the cover plate includes a central region and an edge region surrounding the central region, the central region protruding towards one side of the cover plate relative to the edge region; the current collector is disposed between the electrode assembly and the cover plate, and the current collector includes a first connecting part and a second connecting part, at least a portion of the first connecting part is welded to the central region, and the second connecting part is disposed around the outer periphery of the first connecting part; the cover plate, the second connecting part, and the sidewall are connected by solder; the secondary battery also includes a limiting structure, which is disposed around the central region, and along the axial direction of the secondary battery, one end of the limiting structure abuts against the first connecting part and / or the second connecting part, and the other end abuts against the edge region and is insulated from the edge region.

[0006] In one embodiment of the secondary battery of this utility model, at least a portion of the second connecting part extends outward along the axial direction of the housing and is clamped between the outer periphery of the side wall and the cover plate. The second connecting part, the inner wall of the side wall and the cover plate are connected by welding.

[0007] In one embodiment of the secondary battery of this utility model, the cover plate includes a body portion, a deformable portion and a third connecting portion. The body portion is located at the center of the cover plate. On a cross section passing through the axis of the shell, one end of the deformable portion is connected to the third connecting portion and the other end is connected to the body portion. The third connecting portion extends in a direction away from the electrode assembly. An annular recess is formed on the side of the deformable portion facing the electrode assembly, and an annular protrusion is formed on the side of the deformable portion away from the electrode assembly. The inner wall of the side wall and the outer periphery of the third connecting portion are connected by solder.

[0008] In one embodiment of the secondary battery of this utility model, the limiting structure is an insulating component with compressibility and resilience that is independent of the current collector.

[0009] In one embodiment of the secondary battery of this utility model, a stepped portion is provided on the side of the limiting structure facing the current collecting member. The stepped portion is provided on the outer periphery of the limiting structure, and a gap is formed between the stepped portion and the current collecting member located on the radial outer side of the limiting structure.

[0010] In one embodiment of the secondary battery of this utility model, the limiting structure includes a protrusion disposed on the current collector and protruding to one side of the electrode assembly, and the protrusion has an insulating material on at least one surface near the electrode assembly.

[0011] In one embodiment of the secondary battery of this utility model, the second connecting part includes a plurality of pins arranged circumferentially along the first connecting part, each pin being welded to the inner wall of the cover plate and the side wall; the limiting structure includes a plurality of protrusions arranged circumferentially along the central region, and each second connecting part corresponds to at least one protrusion along the radial direction of the current collecting member.

[0012] In one embodiment of the secondary battery of this utility model, the first connection part includes a plurality of tab connection parts welded to the central region. The plurality of tab connection parts are arranged circumferentially at intervals along the central region. Along the radial direction of the current collector, a protrusion and a tab connection part are correspondingly provided on the radial inner side of each pin. The protrusion is disposed between the pin and the tab connection part. The protrusion and the current collector are integrally formed. The protrusion forms a groove on the side facing away from the electrode assembly. The sidewall of the groove is inclined relative to the axial direction of the shell.

[0013] This utility model also provides a battery pack, which includes any of the above-mentioned secondary batteries.

[0014] This utility model also provides an electronic device that includes the aforementioned battery pack.

[0015] The beneficial effects of this utility model are as follows: The secondary battery proposed in this utility model has a limiting structure set in the edge area of ​​the electrode assembly. One end of the limiting structure abuts against the first connecting part and / or the second connecting part, and the other end abuts against the edge area. The limiting structure can restrict the displacement of the current collector component toward the electrode assembly, thereby limiting the second connecting part. This improves the assembly accuracy of the second connecting part, the shell and the cover plate, reduces the probability of defects such as welding explosions, collapse and desoldering, and improves the welding quality. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] In the attached diagram:

[0018] Figure 1 This is a schematic diagram of the structure of a secondary battery according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the electrode assembly in one embodiment of the secondary battery of this utility model;

[0020] Figure 3 for Figure 1 A three-dimensional schematic diagram of a magnified view of a portion of point A in the middle;

[0021] Figure 4 for Figure 3 A schematic diagram of a magnified view of a portion at point B in the middle;

[0022] Figure 5 This is a schematic diagram of the structure of a secondary battery according to an embodiment of the present invention;

[0023] Figure 6 for Figure 5 A three-dimensional schematic diagram of a magnified view of a portion at point C in the middle;

[0024] Figure 7 for Figure 6 A schematic diagram of a magnified view of a portion at point D;

[0025] Figure 8 This is a partially enlarged schematic diagram of the current collector and electrode assembly in one embodiment of the secondary battery of this utility model;

[0026] Figure 9 This is a schematic diagram of an embodiment of the battery pack of this utility model;

[0027] Figure 10 This is a schematic diagram of an embodiment of the electronic device of this utility model.

[0028] The attached figures are labeled as follows:

[0029] 1. Electronic device; 10. Battery pack; 11. Working part; 101. Housing; 102. Cover; 100. Secondary battery; 110. Shell; 111. End wall; 112. Side wall; 1121. Inner wall; 113. Opening; 114. Second end face; 120. Electrode assembly; 121. First electrode; 1211. Negative current collector; 1212. First coated area; 1213. First uncoated area; 122. Separator; 123. Second electrode; 1231. Positive current collector; 1232. Second coated area; 1233. Second uncoated area; 124. 125. First electrode tab; 126. Second electrode tab; 127. Central region; 128. Edge region; 130. Current collector; 131. First connecting part; 1311. Electrode tab connecting part; 132. Second connecting part; 1321. Pin; 1322. First end face; 140. Cover plate; 141. Body part; 142. Deformable part; 143. Third connecting part; 1431. Outer periphery; 144. Third end face; 145. Recess; 146. Protrusion; 150. Electrode post; 160. Limiting structure; 161. Stepped part; 162. Protrusion; 163. Groove. Detailed Implementation

[0030] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0031] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0032] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0033] Please see Figures 1 to 10 This utility model provides a secondary battery 100, a battery pack 10, and an electronic device 1. By setting a limiting structure 160 in the edge region 127 of the electrode assembly 120, the limiting structure 160 can restrict the displacement of the current collector 130 toward the electrode assembly 120, thereby limiting the second connection part 132. This improves the assembly accuracy of the second connection part 132, the housing 110, and the cover plate 140, reduces the probability of defects such as welding explosions, collapses, and desoldering, and improves the welding quality.

[0034] Please see Figure 1 This utility model provides a secondary battery 100, which includes a cover plate 140, a shell 110, an electrode assembly 120, a current collector 130, and a terminal post 150.

[0035] Please see Figure 1 The housing 110 includes a sidewall 112, which forms a circumferentially surrounding cavity. The cavity is used to accommodate an electrode assembly 120, an electrolyte (not shown), and other components. The cavity has at least one opening 113 at each axial end, and a cover plate 140 seals at least one opening 113. In one embodiment, the housing 110 has openings 113 at opposite ends of the cavity, each opening 113 being closed by an end cap. In this embodiment, the housing 110 has an opening 113 at one end of the cavity, and an end wall 111 integrally formed with the surrounding sidewall 112 at the other end. The end wall 111 and the sidewall 112 are integrally stamped or cast. The circumference of the sidewall 112 is not limited and can be cylindrical, cuboid or prism-shaped, or can be along any other closed-loop contour that can match the end wall 111. In this embodiment, the outer edge of the end wall 111 is circular, the sidewall 112 is cylindrical and surrounds the outer edge of the end wall 111, and a circular opening 113 is formed at the end of the sidewall 112 away from the end wall 111. The end cap that closes the opening 113 is also circular.

[0036] Please see Figure 1 and Figure 2 The electrode assembly 120 is disposed within the receiving cavity of the housing 110. The electrode assembly 120 is a component in the secondary battery 100 where an electrochemical reaction occurs. The housing 110 may contain one or more electrode assemblies 120. The electrode assembly 120 includes a wound structure formed by stacking and winding a first electrode 121, a second electrode 123, and a separator 122. The first electrode 121 and the second electrode 123 have opposite polarities. In some embodiments, the first electrode 121 is a positive electrode and the second electrode 123 is a negative electrode. In other embodiments, the first electrode 121 is a negative electrode and the second electrode 123 is a positive electrode.

[0037] Please see Figure 1 and Figure 2 In this embodiment, the first electrode 121 is a negative electrode. The first electrode 121 includes a negative current collector 1211 and a negative active material. The negative active material is coated on the surface of the negative current collector 1211. The negative current collector 1211 includes a first coated area 1212 coated with active material and a first uncoated area 1213 uncoated with active material. The first uncoated area 1213 is located at the end of the first electrode 121. The first uncoated area 1213 extends out of the diaphragm 122 along the winding axis of the electrode assembly 120 to form an electrode tab. In order to distinguish the electrode tab formed by the second electrode 123, the electrode tab located on the first electrode 121 is called the first electrode tab 124. The first electrode tab 124 is the corresponding negative electrode tab.

[0038] Please see Figures 1 to 2 The second electrode 123 is a positive electrode. Specifically, the second electrode 123 includes a positive current collector 1231 and a positive active material. The positive active material is coated on the surface of the positive current collector 1231. The positive current collector 1231 includes a second coated area 1232 coated with active material and a second uncoated area 1233 uncoated with active material. The second uncoated area 1233 is located at the end of the second electrode 123. The other end of the second uncoated area 1233 extends out of the diaphragm 122 along the winding axis of the electrode assembly 120 and is bent toward the winding axis to form a second tab 125. The second tab 125 is the corresponding positive tab.

[0039] Please see Figures 1 to 2 A separator 122 is disposed between the first electrode 121 and the second electrode 123 to isolate the positive electrode active material layer and the negative electrode active material layer. Taking a lithium-ion secondary battery 100 as an example, the positive electrode current collector 1231 can be made of aluminum, and the positive electrode active material layer includes positive electrode active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode current collector 1211 can be made of copper, and the negative electrode active material layer includes negative electrode active material, which can be carbon or silicon, etc. The substrate material of the separator 122 can be polypropylene (PP) or polyethylene (PE), etc. To protect and insulate the electrode assembly 120, an insulating film can also be wrapped around the electrode assembly 120. The insulating film can be synthesized from PP, PE, polyethylene terephthalate (PET), polyvinyl chloride (PVC), or other polymer materials.

[0040] Please see Figure 1 and Figure 2Furthermore, if the first tab 124 faces the end wall 111 or the opening 113, then the second tab 125 faces the other end of the housing 110. In this embodiment, the second tab 125 faces the end wall 111 and is electrically connected to the post 150, making the post 150 positively charged. The first tab 124 faces the opening 113, and the housing 110 is electrically connected to the first tab 124, thus becoming negatively charged. However, in another embodiment, the first tab 124 can be connected to the post 150, and the second tab 125 can be connected to the housing 110.

[0041] Please see Figure 1 The secondary battery 100 also includes a terminal post 150, which is fixed to the end wall 111 and electrically connected to the electrode assembly 120. Specifically, the end wall 111 is provided with a terminal post hole, and the terminal post 150 is installed through the terminal post hole and insulated from the end wall 111. The end of the terminal post 150 facing the electrode assembly 120 passes through the end wall 111 and is directly electrically connected to the second electrode tab 125 or indirectly connected via a transfer connection. The structure of the terminal post 150 can be any suitable form that can pass through the end wall 111 and be electrically connected to the second electrode tab 125 of the electrode assembly 120. For example, the cross-section can be circular, square, prismatic, or an irregular contour that can achieve stable conductivity. The shape of the terminal post hole corresponds to the shape of the terminal post 150. In this embodiment, the cross-section of the terminal post 150 is circular.

[0042] Please see Figure 3 In this embodiment, the end face of the electrode assembly 120 facing the cover plate 140 includes a central region 126 and an edge region 127 surrounding the central region 126. The central region 126 protrudes towards the cover plate 140 relative to the edge region 127. It can be understood that the central region 126 is a region with a relatively large and stable number of stacked layers of the first tabs 124, while the number of stacked layers of the first tabs 124 is smaller closer to the edge of the electrode assembly 120, making the edge region 127 lower than the central region 126. In some embodiments, in order to prevent the first tabs 124 located at the edge of the electrode assembly 120 from forming a protrusion protruding from the radial outer periphery of the electrode assembly 120 when bent, thereby affecting the housing insertion, a portion of the first uncoated area 1213 on the side away from the winding axis is cut off. This cut-off area forms the edge region 127 lower than the central region 126 after winding.

[0043] Please see Figure 3 and Figure 4The secondary battery 100 also includes a current collector 130, which is disposed between the electrode assembly 120 and the cover plate 140. The current collector 130 includes a first connecting portion 131 and a second connecting portion 132. At least a portion of the first connecting portion 131 is welded to the first tab 124 of the electrode assembly 120. In this embodiment, at least a portion of the first connecting portion 131 is welded to the first tab 124 of the central region 126. The welding method can be ultrasonic welding, resistance welding, laser welding, etc., and is not limited thereto. In this embodiment, laser welding is used. The first tab 124 is the negative electrode tab, and copper is the preferred material for the current collector 130. It should be noted that the first connecting portion 131 is the part where the current collector 130 and the first tab 124 are attached. For example, it can be disc-shaped and can be used for welding the current collector 130 and the first tab 124. To improve the ease of positioning, processing, interchangeability, and uniformity of the current collection component 130 during installation, the first connecting part 131 in this embodiment adopts a circular structure. The second connecting part 132 is arranged around the outer periphery of the first connecting part 131. The second connecting part 132 can be an integral closed ring structure or one or more arc-shaped structures, and there is no limitation on this.

[0044] Please see Figures 3 to 8 The secondary battery 100 also includes a limiting structure 160, which surrounds the central region 126 and is located in the edge region 127. It should be noted that the accommodating space required by the limiting structure 160 can be achieved by a recess in the edge region 127 relative to the central region 126, or by a recess in the current collector 130 facing away from the electrode assembly 120, or a combination of both; no limitation is made thereto. Along the axial direction of the housing 110 (e.g., Figure 3 and Figure 5(As shown in the direction of the O to O1 axis), the two ends of the limiting structure 160 abut against the current collecting member 130 and the edge region 127 respectively. The shape of the limiting structure 160 is not limited. In one embodiment, the second connecting part 132 is a closed ring, and the limiting structure 160 is a closed or open ring structure. In another embodiment, the second connecting part 132 includes a plurality of pins 1321 spaced apart. The limiting structure 160 is a ring structure, and the part that contacts the pins 1321 protrudes from the rest of the part and abuts against the side of the pins 1321 facing the electrode assembly 120. The ring structure facilitates centering and positioning, and the partially protruding structures can form radially extending exhaust channels, which facilitates the exhaust of the secondary battery 100. The limiting structure 160 can restrict the displacement of the current collector 130 toward the electrode assembly 120, thereby limiting the second connection part 132, so as to improve the assembly accuracy of the second connection part 132, the housing 110 and the cover plate 140, reduce the probability of defects such as welding explosions, collapse and desoldering, and thus improve the welding quality.

[0045] Furthermore, to prevent the second electrode 123 of the electrode assembly 120 from short-circuiting with the current collector 130 through the limiting structure 160, the limiting structure 160 is configured to be insulated from the edge region 127. In one embodiment, the limiting structure 160 is an insulating material with compression resilience independent of the current collector 130, such as: soluble polytetrafluoroethylene (PFA), polybutylene terephthalate (PBT), liquid crystal polymer (LCP), polyphenylene sulfide (PPS), polycarbonate (PC), or polypropylene (PP), etc.

[0046] The end of the second connecting portion 132 facing away from the electrode assembly 120 is defined as the first end face 1322, the end of the housing 110 facing away from the electrode assembly 120 is defined as the second end face 114, and the end of the cover plate 140 facing away from the electrode assembly 120 is defined as the third end face 144. Since the limiting structure 160 can restrict the displacement of the current collector 130 towards the electrode assembly 120, it can prevent the first end face 1322 from being lower than the second end face 114 and the third end face 144. In some cases, due to dimensional errors in the current collector 130, cover plate 140, and sidewall 112 during production, the first end face 1322 may be higher than the second end face 114 and the third end face 144. In such cases, pressure can be applied to the current collector 130 to reduce its height, thereby making the first end face 1322, the second end face 114, and the third end face 144 flush or nearly flush, thus improving welding quality.

[0047] Please see Figure 3 and Figure 6 At least a portion of the second connecting portion 132 extends outward from the inner wall 1121 of the housing 110 and is sandwiched between the side wall 112 and the outer periphery of the cover plate 140. Specifically, from the inside to the outside along the radial direction of the housing 110, the components are the cover plate 140, the second connecting portion 132, and the side wall 112. The cover plate 140 can have various structures, which are not limited; for example, it can be disc-shaped or have an upward-flanged outer periphery. The second connecting portion 132, the inner wall 1121 of the side wall 112, and the cover plate 140 are connected by a welding stamp. Top welding can be used, achieving triple welding of the current collector 130, the housing 110, and the cover plate 140 in a single welding process. This arrangement simplifies the manufacturing process and improves welding efficiency.

[0048] Please see Figures 3 to 7In one embodiment of the secondary battery 100 of this utility model, the cover plate 140 includes a body portion 141, a deformable portion 142, and a third connecting portion 143. The body portion 141 is located at the center of the cover plate 140. On a cross-section passing through the axis of the housing 110, one end of the deformable portion 142 is connected to the third connecting portion 143, and the other end is connected to the body portion 141. The third connecting portion 143 extends in a direction away from the electrode assembly 120. An annular recess 145 is formed on the side of the deformable portion 142 facing the electrode assembly 120, and an annular protrusion 146 is formed on the side of the deformable portion 142 away from the electrode assembly 120. In this embodiment, the second connecting portion 132, the inner wall 1121 of the side wall 112, and the outer periphery 1431 of the third connecting portion 143 are connected by solder to form a triple-welded area. When the cover plate 140 is installed into the housing 110, the deformable portion 142 is pressed down along the axial direction of the housing 110. The deformable portion 142 pushes the third connecting portion 143 to move radially outward from the cover plate 140, thereby squeezing the second connecting portion 132 to tilt radially outward from the cover plate 140, so that the outer peripheral surface of the second connecting portion 132 is in transition fit or interference fit with the inner wall 1121 of the side wall 112. It should be noted that before the cover plate 140 is pressed down, there is an installation gap between the outer peripheral surface of the second connecting portion 132 and the inner wall 1121 of the side wall 112. This arrangement facilitates the insertion of the current collecting member 130 into the housing. Without the aforementioned installation gap, the current collecting member 130 would need to be inserted into the housing using a tool with an outwardly flared opening 113, which would make assembly difficult and risk generating metal shavings from friction with the housing 110. This arrangement also facilitates pressing the second connecting portion 132 tightly against the side wall 112, which can improve welding efficiency and welding quality.

[0049] Please see Figure 3 and Figure 4 In one embodiment of the secondary battery 100 of this utility model, the limiting structure 160 is provided with a recessed step portion 161 on the side facing the current collecting member 130, so that a gap is formed between the step portion 161 and the current collecting member 130. The step portion 161 is provided on the outer periphery of the limiting structure 160, and the gap is located on the radial outer side of the step portion 161. The stepped portion 161 is located near the inner wall 1121 of the housing 110. Projected along the axial direction of the housing 110, the area where the second connecting portion 132 and the third connecting portion 143 are connected at least partially overlaps with the stepped portion 161. The gap between the stepped portion 161 and the flow collecting member 130 forms a clearance space. When the second connecting portion 132 and the third connecting portion 143 are assembled and pressed down, a certain amount of deformation of the second connecting portion 132 can be accommodated, avoiding interference between the limiting structure 160 and the second connecting portion 132 and hindering the pressing down of the second connecting portion 132. This arrangement is conducive to achieving the alignment of the first end face 1322, the second end face 114 and the third end face 144, thereby improving the welding quality.

[0050] Please see Figures 6 to 8In one embodiment of the secondary battery 100 of this utility model, the limiting structure 160 includes a protrusion 162 disposed on the current collector 130 and protruding towards the electrode assembly 120. The protrusion 162 can be formed in various ways, such as by stamping, bonding, riveting, injection molding, or snap-fitting, and is not limited thereto. To achieve insulation between the protrusion 162 and the electrode assembly 120, the protrusion 162 has insulating material on at least one surface near the electrode assembly 120.

[0051] Please see Figure 8 In one embodiment of the secondary battery 100 of this utility model, the second connecting portion 132 includes a plurality of pins 1321 arranged circumferentially along the first connecting portion 131, each pin 1321 being welded to the cover plate 140 and the inner wall 1121 of the side wall 112. The number of pins 1321 is not limited; in this embodiment, there are four pins 1321, which are evenly connected to the outer periphery of the first connecting portion 131. The limiting structure 160 includes a plurality of protrusions 162, which are arranged circumferentially along the central region 126. Along the radial direction of the current collecting member 130, each second connecting portion 132 corresponds to at least one protrusion 162. This design, through precise matching, enables the protrusion 162 to play an optimal limiting role, that is, to precisely limit the displacement of the second connecting part 132 toward the electrode assembly 120. In turn, it can improve the assembly accuracy of the second connecting part 132, the housing 110 and the cover plate 140, reduce the probability of defects such as welding spalls, collapse and desoldering, and thus improve the welding quality.

[0052] Please see Figure 8In one embodiment of the secondary battery 100 of this utility model, the first connecting portion 131 includes a plurality of tab connecting portions 1311 welded to the central region 126. The plurality of tab connecting portions 1311 are arranged at intervals along the circumference of the central region 126. Along the radial direction of the current collector 130, a protrusion 162 and a tab connecting portion 1311 are correspondingly provided on the radially inner side of each pin 1321, and the protrusion 162 is disposed between the pin 1321 and the tab connecting portion 1311. This arrangement can improve the current carrying effect. Preferably, the protrusion 162 and the current collector 130 are integrally formed. The integral forming arrangement is beneficial to improving the structural strength of the current collector 130, and also reduces the number of parts and reduces the production cost. Further, the protrusion 162 forms a groove 163 on the side facing away from the electrode assembly 120, and the sidewall of the groove 163 is inclined relative to the axial direction of the housing 110. The protrusion 162 of this structure not only limits the second connecting part 132, but also reduces the height of the groove 163 by applying pressure to the current collecting member 130 to deform it, thus making the first end face 1322 higher than the second end face 114 and the third end face 144, which may be due to dimensional errors in the current collecting member 130, cover plate 140 and side wall 112 during the production process. This facilitates the first end face 1322, the second end face 114 and the third end face 144 to be flush or nearly flush. Furthermore, it can also deform when the secondary battery 100 is subjected to external vibration force, so as to relieve the tension between the welding part of the second connecting part 132 and the welding part of the electrode connecting part 1311, thereby improving the problem that the welding part of the second connecting part 132 and the welding part of the electrode connecting part 1311 are prone to welding failure.

[0053] Please see Figure 9 This utility model also provides a battery pack 10, which includes the secondary battery 100 described above. In one embodiment of the battery pack 10, the battery pack 10 includes a housing 101, a cover 102, and multiple secondary batteries 100. The multiple secondary batteries 100 are placed in the housing 101 and are connected in series or parallel, or a combination of series and parallel connections. The cover 102 covers the housing 101 to protect the multiple secondary batteries 100. It should be noted that, in addition to the secondary battery 100 of this utility model, the battery pack 10 may also include a battery pack thermal management system, circuit board, etc. The battery pack 10 can be a battery module, a battery pack, an energy storage cabinet, etc.; these will not be described in detail here.

[0054] Please see Figure 10This utility model also provides an electronic device 1, which includes the aforementioned battery pack 10. A working part 11 is electrically connected to the battery pack 10 to obtain electrical power. As an example, the electronic device 1 is a vehicle, which can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part 11 is the vehicle body, and the battery pack 10 is located at the bottom of the vehicle body, providing electrical power for the vehicle's operation or the operation of its internal electrical components. However, in other embodiments, the electronic device 1 can also be a mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part 11 can be a unit component capable of obtaining electrical power from the battery pack 10 and performing corresponding work, such as a fan blade rotation unit or a vacuum cleaner suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electronic device 1.

[0055] The beneficial effects of this utility model are as follows: The secondary battery proposed in this utility model has a limiting structure set in the edge area of ​​the electrode assembly. One end of the limiting structure abuts against the first connecting part and / or the second connecting part, and the other end abuts against the edge area. The limiting structure can restrict the displacement of the current collector component toward the electrode assembly, thereby limiting the second connecting part. This improves the assembly accuracy of the second connecting part, the shell and the cover plate, reduces the probability of defects such as welding explosions, collapse and desoldering, and improves the welding quality.

[0056] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A secondary battery, characterized in that, include: A housing, including sidewalls, said sidewalls forming at least one opening in the circumferential direction; Cover plate, sealing at least one of the openings; An electrode assembly is housed within the housing. The end face of the electrode assembly facing the cover plate includes a central region and an edge region surrounding the central region. The central region protrudes toward one side of the cover plate relative to the edge region. A current collector is disposed between the electrode assembly and the cover plate. The current collector includes a first connecting part and a second connecting part. At least a portion of the first connecting part is welded to the central region. The second connecting part is disposed around the outer periphery of the first connecting part. The cover plate, the second connecting part and the side wall are connected by solder. The secondary battery further includes a limiting structure, which is arranged around the central region. Along the axial direction of the secondary battery, one end of the limiting structure abuts against the first connecting part and / or the second connecting part, and the other end abuts against the edge region and is insulated from the edge region.

2. The secondary battery according to claim 1, characterized in that, At least a portion of the second connecting portion extends outward along the axial direction of the housing and is clamped between the outer periphery of the side wall and the cover plate. The second connecting portion, the inner wall of the side wall, and the cover plate are connected by the solder joint.

3. The secondary battery according to claim 2, characterized in that, The cover plate includes a body portion, a deformable portion, and a third connecting portion. The body portion is located at the center of the cover plate. On a cross section passing through the axis of the housing, one end of the deformable portion is connected to the third connecting portion, and the other end is connected to the body portion. The third connecting portion extends in a direction away from the electrode assembly. An annular recess is formed on the side of the deformable portion facing the electrode assembly, and an annular protrusion is formed on the side of the deformable portion away from the electrode assembly. The second connecting portion, the inner wall of the side wall, and the outer periphery of the third connecting portion are connected by the solder mark.

4. The secondary battery according to any one of claims 1 to 3, characterized in that, The limiting structure is an insulating component with compressibility and resilience, independent of the current collecting member.

5. The secondary battery according to claim 1, characterized in that, The limiting structure has a stepped portion on the side facing the flow collecting member. The stepped portion is located on the outer periphery of the limiting structure, and a gap is formed between the stepped portion and the flow collecting member on the radially outer side of the limiting structure.

6. The secondary battery according to any one of claims 1 to 3, characterized in that, The limiting structure includes a protrusion disposed on the current collector and protruding to one side of the electrode assembly, the protrusion having an insulating material on at least one surface near the electrode assembly.

7. The secondary battery according to claim 6, characterized in that, The second connecting portion includes a plurality of pins arranged circumferentially along the first connecting portion, and each pin is welded to the inner wall of the cover plate and the side wall; The limiting structure includes a plurality of protrusions, which are arranged circumferentially along the central region. Along the radial direction of the flow collecting member, each second connecting portion corresponds to at least one of the protrusions.

8. The secondary battery according to claim 7, characterized in that, The first connection portion includes a plurality of electrode connection portions welded to the central region, the plurality of electrode connection portions being arranged circumferentially at intervals along the central region; along the radial direction of the current collector, each pin is provided with a protrusion and an electrode connection portion corresponding to its radial inner side, the protrusion being disposed between the pin and the electrode connection portion; wherein, the protrusion and the current collector are integrally formed, the protrusion forming a groove on the side facing away from the electrode assembly, the sidewall of the groove being inclined relative to the axial direction of the housing.

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

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

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