Cylindrical battery, battery pack, and electronic device

Abstract

The utility model provides a kind of cylindrical battery, battery pack and electronic device, the cylindrical battery includes: shell, electrode terminal, electrode assembly and liquid injection plug;Electrode terminal insulation is fixed in shell, and it has first through-hole;Electrode assembly is contained in the containing space, and it has with the positive electrode end of electrode terminal electric connection;Electrode assembly has the winding core through -hole of through electrode assembly;Liquid injection plug is installed in first through-hole, and it includes the convex end extending towards containing space direction, convex end has radially protruding protruding portion, at least part of winding core through -hole projection falls into the projection of convex end;Positive electrode end gradually extends to the side of deviating from electrode terminal and forms inclined end surface in the direction of radially towards winding core through -hole;Convex end has bottom wall, protruding portion has the annular inclined wall of connecting bottom wall, annular inclined wall and inclined end surface are in the same direction and oppositely arranged, and are formed with gap A.The utility model can improve the problem that liquid injection plug is installed in first through-hole and is easy to interfere with electrode assembly.

Description

Technical Field

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

[0002] In existing cylindrical battery technology, a through-hole is typically made on the positive electrode terminal for injecting electrolyte, and a sealing plug is installed at the through-hole after electrolyte injection. However, due to the limited axial installation space of the cylindrical battery, the portion of the sealing plug extending into the casing is often close to the axial distance between the electrode assembly and the casing. Therefore, there is a risk that the sealing plug may come into contact with or even press against the separator or electrode plate of the electrode assembly. This situation can easily damage the insulation between the positive and negative electrodes, leading to an internal short circuit. This problem severely restricts the safety and reliability of cylindrical batteries. Utility Model Content

[0003] This utility model provides a cylindrical battery, battery pack, and electronic device to solve the technical problem that when the liquid injection plug is installed in the through hole on the electrode terminal, it is easy to come into contact with the diaphragm or electrode sheet of the electrode assembly, causing an internal short circuit.

[0004] This utility model provides a cylindrical battery, which includes: a housing, electrode terminals, an electrode assembly, and a liquid injection plug; a receiving space is formed inside the housing; the electrode terminals are fixedly disposed in the housing and insulated from the housing, and have a first through hole communicating with the receiving space; the electrode assembly is received in the receiving space, and the electrode assembly has a positive terminal and a negative terminal arranged opposite to each other along the axial direction of the electrode assembly, the positive terminal being arranged opposite to and electrically connected to the electrode terminals, and the electrode assembly having a core through hole penetrating the electrode assembly along the axial direction of the electrode assembly; the liquid injection plug is installed in the first through hole and includes a direction facing the receiving space. The extended protruding end has a protrusion that protrudes radially along the electrode assembly, and at least a portion of the projection of the core through hole falls within the projection of the protruding end along the axial direction of the cylindrical battery; wherein, at least a portion near the positive end of the core through hole extends gradually inclinedly toward the side away from the electrode terminal in the radial direction of the electrode assembly toward the core through hole and forms an inclined end face; the protruding end has a bottom wall near the electrode assembly, and the protrusion has an annular inclined wall connected to the bottom wall, the annular inclined wall and the inclined end face extend in the same direction and are disposed opposite each other, and a gap A is formed between the annular inclined wall and the inclined end face.

[0005] In one embodiment of the present invention, the injection plug includes a rotation axis, and the angle between the annular inclined wall and the rotation axis is θ, where 5°≤θ≤30°.

[0006] In one embodiment of this utility model, the electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator separating the positive and negative electrode sheets. The positive electrode sheet, negative electrode sheet, and separator are stacked and wound to form a core, and the core includes a core through hole. The positive electrode sheet includes a positive current collector and a positive active material layer coated on the positive current collector. The positive current collector also includes an uncoated portion that is not coated with the positive active material layer. At least a portion of the uncoated portion forms a positive electrode tab, which is electrically connected to an electrode terminal. The positive electrode sheet includes a head region located at the beginning of the winding and a middle region connected to the head region. The uncoated portion located in the head region does not have a positive electrode tab, and the head region is wound to form an inner ring portion of the core. The positive electrode tabs of the uncoated portion located in the middle region are bent toward the central axis of the electrode assembly and stacked to form a tab stack, which is welded to the electrode terminal.

[0007] The tab stack extends at least partially to the inner ring portion of the core between the electrode terminal and the electrode terminal; along the direction from the electrode assembly to the electrode terminal, the end of the diaphragm near the electrode terminal extends beyond the end of the positive electrode sheet near the electrode terminal and forms a diaphragm end face, part of which forms an inclined end face.

[0008] In one embodiment of the present invention, along the axial direction, the inner edge of the projection profile of the electrode stack is located on the outer periphery of the outer edge of the projection profile of the inclined end face, and a gap B is formed between them.

[0009] In one embodiment of the present invention, the electrode stack portion extends at least partially to the inner ring portion of the core facing the electrode terminal and between the electrode terminal; at least a portion of the uncoated portion is coated with an insulating layer, and along the direction from the electrode assembly to the electrode terminal, one end of the insulating layer near the electrode terminal extends beyond the end of the diaphragm near the electrode terminal and forms an electrode end face, and a portion of the electrode end face forms an inclined end face.

[0010] In one embodiment of this utility model, a stop portion is connected to the side of the protruding end away from the electrode assembly. The stop portion is located outside the first through hole and abuts against the outer periphery of the first through hole. The protruding end is also provided with a recessed portion, which is located on the side of the protruding end away from the electrode assembly. The recessed portion is provided corresponding to the first through hole and is compressed at the first through hole to achieve a seal relative to the first through hole. The electrode terminal also includes a columnar portion and a first limiting portion and a second limiting portion respectively connected to the two opposite ends along the axial direction of the columnar portion. The columnar portion is installed through the housing. The first limiting portion is located in the receiving space, and the second limiting portion is located outside the housing. A groove portion exposing the first through hole is provided on the side of the columnar portion away from the receiving space. A cover plate is fitted to the groove portion, and the cover plate seals the groove portion.

[0011] In one embodiment of the present invention, the bottom wall of the protruding end is a plane, and the bottom wall is provided with a first recess that is recessed toward the side of the electrode terminal; the stop portion is provided with a second recess on the side away from the electrode assembly, and the second recess is recessed toward the side of the protruding end.

[0012] In one embodiment of the present invention, the diameter of the through hole of the core is d1, the diameter of the outer periphery of the protrusion is d2, and d2 > d1; the diameter of the first through hole is d3, and d2 > d3.

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

[0014] This invention further provides an electronic device that includes the aforementioned battery pack.

[0015] The beneficial effects of this invention are as follows: By providing an annular inclined wall at the protruding end of the injection plug extending into the housing, and this annular inclined wall being opposite to and inclined in the same direction to the inclined end face of the electrode assembly facing the electrode terminals, and forming a gap A between them, at least a portion of the projection of the core through hole falls within the projection of the protruding end. This arrangement, due to the effective physical clearance space formed by the relative inclination between the annular inclined wall and the inclined end face, reduces the probability of contact between the injection plug and the electrode assembly's electrode plates or separator while maintaining the same installation height. This reduces the probability of internal short circuits caused by contact between the positive and negative electrode plates, thereby improving the safety and reliability of the cylindrical battery. Simultaneously, it allows the relative position between the injection plug and the core through hole to be closer, reducing the occupied housing height space and improving the volumetric energy density of the cylindrical battery. Furthermore, the gap A also provides space for the separator to shrink during the charging and discharging process of the electrode assembly, preventing the injection plug from compressing the electrode assembly and affecting the normal use of the separator. 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 A partial structural cross-sectional view of a cylindrical battery provided in an embodiment of the present invention;

[0019] Figure 2 for Figure 1 A magnified view of a portion of region A in the middle;

[0020] Figure 3 for Figure 1 A magnified view of a portion of region B in the middle;

[0021] Figure 4 This is a schematic diagram of the unfolded positive electrode sheet provided in one embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the positive end of another embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of a structure in one embodiment of the present invention, in which the diameter d1 of the core through hole is greater than the maximum radial dimension d2 of the protrusion;

[0024] Figure 7 This is a schematic diagram of the setting position structure between the initial electrode tab and the through hole of the core in an embodiment of the present invention;

[0025] Figure 8 This is an axial sectional view of the injection plug provided in one embodiment of the present invention;

[0026] Figure 9 This is a schematic diagram of the structure of the injection plug sealing the first through hole and circumferentially abutting the second through hole in one embodiment of the present invention;

[0027] Figure 10 This is a schematic diagram of a structure in one embodiment of the present invention, showing that the axial distance between the protrusion and the flow collecting member is dimension H2.

[0028] Figure 11 This is a schematic diagram of the structure in one embodiment of the present invention, showing the annular inclined wall on the injection plug and the inclined end face on the electrode assembly being arranged opposite to each other;

[0029] Figure 12 This is a schematic diagram of the structure of the inclined surface formed on the end face of the electrode sheet in one embodiment of the present invention;

[0030] Figure 13 This is a schematic diagram of an example of the battery pack of this utility model;

[0031] Figure 14 This is a schematic diagram showing the angle θ between the annular inclined wall of the injection plug and the axis of rotation in one embodiment of the present invention.

[0032] Figure 15 This is a partial structural diagram of the injection plug installed in the first through hole according to another embodiment of the present invention.

[0033] Figure 16 This is a schematic diagram of an example of the battery pack of this utility model;

[0034] Figure 17 This is a schematic diagram of an example of the electronic device of this utility model.

[0035] The attached figures are labeled as follows:

[0036] 100. Cylindrical battery; 110. Casing; 111. Mounting hole; 112. End wall; 113. Side wall; 114. Receiving space; 120. Electrode assembly; 121. Positive electrode; 1211. Positive current collector; 1212. Positive active material layer; 1213. Uncoated area; 1214. Positive electrode tab; 12141. Initial positive electrode tab; 1215. Head region; 1216. Middle region; 1217. Positive terminal; 12171. Positive terminal face; 1218. Tab stack; 12181. Inner edge; 1219. Electrode end face; 122. Negative electrode; 123. Separator; 1231. Separator end face; 124. Core through hole; 125. Inclined end face; 1251. Outer edge; 126. Ceramic insulating layer; 130. Current collector; 131, second through hole; 140, liquid injection plug; 1401, rotation axis; 141, protruding end; 142, recessed portion; 143, bottom wall; 144, first recessed portion; 145, stop portion; 1451, second recessed portion; 146, protruding portion; 1461, annular inclined wall; 150, electrode terminal; 151, first through hole; 1511, rounded corner; 152, first limiting portion; 153, columnar portion; 1531, groove portion; 15311, groove bottom wall; 154, second limiting portion; 155, cover plate; 160, first insulating component; 170, second insulating component; 180, solder mark; 200, battery pack; 210, housing; 211, first housing portion; 212, second housing portion; 300, electronic device; 310, working part. Detailed Implementation

[0037] 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.

[0038] 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.

[0039] 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.

[0040] See Figures 1 to 17 This invention provides a cylindrical battery 100, a battery pack 200, and an electronic device 300. The liquid injection plug 140 in the cylindrical battery 100 extends into the housing 110, and its protruding end 141 includes a protrusion 146 that protrudes radially outward. The minimum radial distance between the electrode stack 1218 inside the housing 110 and the first through hole 151 is L, and the radial distance from the maximum radial dimension of the protrusion 146 to the first through hole 151 is W, where 0 < W < L. This structure, by providing the protrusion 146 and limiting its radial dimension W, not only reduces the probability of the liquid injection plug 140 detaching from the first through hole 151, but also reduces the probability of contact interference between the liquid injection plug 140 and the electrode stack 1218, thereby improving the safety and reliability of the cylindrical battery 100.

[0041] In this invention, the cylindrical battery 100 may include lithium-ion batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this invention are not limited to this.

[0042] Please see Figure 1 The structure of the cylindrical battery 100 is further described below. The cylindrical battery 100 includes: a housing 110, electrode terminals 150, electrode assembly 120, and liquid injection plug 140.

[0043] Please see Figure 1 The housing 110 includes an end wall 112 and a side wall 113 surrounding the end wall 112. As long as a stable sealing and electrical connection can be formed, the connection between the end wall 112 and the side wall 113 can be achieved in a variety of ways, such as integral stamping, integral casting, or separate welding.

[0044] The housing 110, formed by the end wall 112 and side wall 113, has an internal receiving space 114 for accommodating the electrode assembly 120, electrolyte, and other necessary battery components. Specifically, the diameter of the housing 110 can be determined based on the specific dimensions of the electrode assembly 120, for example, a diameter of 46mm and heights of 80mm, 95mm, or 120mm. The housing 110 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. To prevent rust during long-term use, a rust-preventive material, such as nickel, can be plated onto the surface of the housing 110.

[0045] A mounting hole 111 is provided on the end wall 112 of the housing 110. The electrode terminal 150 is mounted in the mounting hole 111 and is insulated relative to the housing 110, with at least a portion of the electrode terminal 150 exposed outside the housing 110. Specifically, see [reference needed]. Figure 2 The electrode terminal 150 includes a columnar portion 153, a first limiting portion 152, and a second limiting portion 154. The first limiting portion 152 and the second limiting portion 154 are respectively disposed at both ends of the columnar portion 153 in the height direction, and both extend from the outer periphery of the columnar portion 153 to the outer periphery of the end wall 112 in the radial direction. The columnar portion 153 passes through the mounting hole 111. The end of the columnar portion 153 facing the electrode assembly 120 is connected to the first limiting portion 152, that is, the first limiting portion 152 is located inside the housing 110. The end of the columnar portion 153 away from the electrode assembly 120 is connected to the second limiting portion 154, that is, the second limiting portion 154 is located outside the housing 110. The cross-section of the first limiting portion 152 and the second limiting portion 154 can be circular, square, prismatic, or other irregular contours that can achieve stable conductivity, etc., and this embodiment does not limit this. Optionally, in order to facilitate the production and processing of the electrode terminal 150, in this embodiment, the outer contour of the first limiting part 152 and the outer contour of the second limiting part 154 are both circular contours coaxially arranged with the columnar part 153.

[0046] Please see Figure 2The end wall 112 is sandwiched between the first limiting portion 152 and the second limiting portion 154. To achieve an insulated connection between the electrode terminal 150 and the end wall 112, a first insulating member 160 is provided between the first limiting portion 152 and the end wall 112. At least a portion of the first insulating member 160 is sandwiched between the inner side of the end wall 112 (the side of the end wall 112 facing the electrode assembly 120) and the first limiting portion 152, thereby achieving insulation between the inner side of the end wall 112 and the first limiting portion 152. A second insulating member 170 is provided between the second limiting portion 154 and the end wall 112. At least a portion of the second insulating member 170 is sandwiched between the outer side of the end wall 112 (the side of the end wall 112 away from the electrode assembly 120) and the second limiting portion 154, thereby achieving insulation between the second limiting portion 154 and the end wall 112. The columnar portion 153 has a groove portion 1531 at one end away from the electrode assembly 120. The groove portion 1531 includes a groove bottom wall 15311, and the groove bottom wall 15311 is provided with a first through hole 151 that communicates with the receiving space 114 of the housing 110.

[0047] Please see Figure 1 and Figure 3 The electrode assembly 120 is housed within the receiving space 114. The electrode assembly 120 is a component in the cylindrical battery 100 where the electrochemical reaction occurs. One or more electrode assemblies 120 may be disposed within the receiving space 114 of the housing 110. Exemplarily, in this embodiment, one electrode assembly 120 is disposed within the receiving space 114 of the housing 110. The electrode assembly 120 includes a positive electrode 121, a negative electrode 122, and a separator 123 separating the positive electrode 121 and the negative electrode 122.

[0048] Please see Figure 4 The positive electrode 121 includes a positive current collector 1211 and a positive active material layer 1212 coated on the positive current collector 1211. The positive current collector 1211 also includes an uncoated portion 1213 without the positive active material layer 1212. At least a portion of the uncoated portion 1213 forms a positive electrode tab 1214. The positive electrode 121 includes a beginning region 1215 located at the beginning of the winding and a middle region 1216 connected to the beginning region 1215. The uncoated portion 1213 located in the beginning region 1215 does not have a positive electrode tab 1214. In this embodiment, the absence of a positive electrode tab 1214 in the uncoated portion 1213 located in the beginning region 1215 can be achieved through a tab cutting process, i.e., the tab portion corresponding to the beginning region 1215 is cut off during the manufacturing process. The beginning region 1215 is wound to form the inner ring portion of the core. It should be noted that the first uncoated part may be coated with an insulating layer, such as a ceramic insulating layer, or it may not be coated with an insulating layer.

[0049] Please see Figure 2 and Figure 4The uncoated portion of the central region 1216 includes a positive electrode tab 1214, which is bent and stacked towards the central axis of the electrode assembly 120 to form a tab stack 1218. The tab stack 1218 is welded to the electrode terminal 150. The tab stack 1218 can be directly welded to the electrode terminal 150, or it can be indirectly welded to the electrode terminal 150 through the current collector 130. This embodiment does not limit this.

[0050] It should be noted that in the actual cylindrical battery 100 product, the tab stack 1218 forms an abutting relationship with the inner ring portion of the winding core facing the electrode terminal 150, that is, the two are at least partially in contact with each other. The gap shown in the accompanying drawings of this utility model between the tab stack 1218 and the inner ring portion of the winding core facing the electrode terminal 150 does not indicate the existence of such a gap in the actual product; the illustration is for illustrative purposes only.

[0051] It should be noted that the negative electrode 122 includes a negative current collector and a negative active material layer coated on the negative current collector. The negative current collector also includes an uncoated portion without the negative active material layer. To distinguish it from the uncoated portion on the positive electrode 121, the uncoated portion here is defined as the negative uncoated portion. The side of the negative uncoated portion facing away from the electrode terminal 150 may include a negative electrode tab. The negative electrode tab is used for electrical connection with the housing 110.

[0052] A separator 123 is disposed between the positive electrode 121 and the negative electrode 122 to isolate the positive active material layer 1212 and the negative active material layer. Taking a lithium-ion cylindrical battery 100 as an example, the positive current collector 1211 can be made of aluminum, and the positive active material layer 1212 includes positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative current collector can be made of copper, and the negative active material layer includes negative active material, which can be carbon or silicon, etc. The substrate material of the separator 123 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.

[0053] Please see Figure 2The injection plug 140 is installed in the first through hole 151 and includes a protruding end 141 extending into the receiving space 114. The protruding end 141 has a protruding portion 146 that protrudes radially along the electrode assembly 120. Specifically, the protruding portion 146 protrudes radially outward relative to the first through hole 151, and the maximum radial dimension of the protruding portion 146 is larger than the dimension of the first through hole 151. The protruding portion 146 may be an annular protrusion structure surrounding the first through hole 151, or it may be a plurality of spaced local protrusions, etc. Optionally, in this embodiment, the protruding portion 146 is an annular protrusion structure surrounding the first through hole 151.

[0054] Please see Figure 2 The minimum radial distance between the tab stack 1218 and the first through hole 151 is L, and the radial distance from the maximum radial dimension of the protrusion 146 to the first through hole 151 is W, where 0 < W < L. It should be noted that the minimum radial distance L between the tab stack 1218 and the first through hole 151 specifically refers to the shortest straight-line length in the radial direction of the cylindrical battery 100 between the inner edge of the tab stack 1218 and the wall of the first through hole 151 on a plane perpendicular to the axis of the cylindrical battery 100 (i.e., in a cross-sectional view). The radial distance W from the maximum radial dimension of the protrusion 146 to the first through hole 151 specifically refers to the straight-line length in the radial direction of the cylindrical battery 100 between the outer periphery of the maximum radial dimension of the protrusion 146 and the wall of the first through hole 151 on the same cross-sectional view.

[0055] In this embodiment, by providing a protrusion 146 on the liquid injection plug 140, a radial stop structure can be formed between the protrusion 146 and the first through hole 151. This stop structure can resist the outward pushing force of the internal pressure on the liquid injection plug 140, thereby reducing the risk of the liquid injection plug 140 coming out of the first through hole 151. In addition, in the axial direction of the housing 110, the installation position of the tab stacking portion 1218 is close to the area where the protrusion 146 is located. If the radial dimension of the protrusion 146 protruding from the first through hole 151 is too large, it is easy to contact or squeeze the tab stacking portion 1218, bringing a risk of short circuit. If the radial dimension of the protrusion 146 protruding from the first through hole 151 is too small, although the probability of contact or extrusion with the tab stacking portion 1218 can be reduced, the stop strength of the protrusion 146 will be weakened, increasing the possibility of the liquid injection plug 140 coming out under the action of internal pressure. In this embodiment, by defining the minimum radial distance between the tab stacking portion 1218 and the first through hole 151 as L, and the radial distance from the maximum radial dimension part of the protrusion 146 to the first through hole 151 as B, and satisfying 0 < B < L. Such a setting can, on the one hand, avoid the probability of contact interference between the protrusion 146 and the tab stacking portion 1218 due to the excessive size of the protrusion 146, thereby reducing the risk of short circuit inside the housing 110; on the other hand, it can also ensure that the protrusion 146 has sufficient mechanical strength and stop function, thereby ensuring the pressure resistance performance of the liquid injection plug 140 and effectively reducing the probability of it coming out of the first through hole 151.

[0056] Please refer to Figure 1 and Figure 2 , on the side of the electrode assembly 120 facing the electrode terminal 150, a current collector member 130 is further provided. The current collector member 130 is welded to the tab stacking portion 1218 and the electrode terminal 150 and is accommodated in the accommodation space 114. The current collector member 130 has a second through hole 131. The second through hole 131 is provided on the side of the first through hole 151 facing the electrode assembly 120. The protruding end 141 passes through the first through hole 151 and the second through hole 131 and extends into the accommodation space 114. The second through hole 131 can be coaxially arranged with the first through hole 151 or non-coaxially arranged. The diameter of the second through hole 131 can be equal to the diameter of the first through hole 151 or larger than the diameter of the first through hole 151. As long as it can be ensured that the second through hole 131 is always arranged around the outer periphery of the first through hole 151.

[0057] It should be noted that the electrical connection method between the current collector member 130 and the tab stacking portion 1218 and the electrode terminal 150 is not limited to one. Optionally, please refer to Figure 2In this embodiment, one side of the current collector 130 abuts against the bottom wall 15311 of the groove, and the other side abuts against the tab stack 1218. Along the axial direction of the first through hole 151, a projection overlap area is formed between the bottom wall 15311 of the groove, the current collector 130, and the tab stack 1218. Penetration welding is performed at the location of the bottom wall 15311 corresponding to this projection overlap area, thereby achieving a one-time welding connection between the bottom wall 15311 of the groove, the current collector 130, and the tab stack 1218, and forming a weld mark 180 on the bottom wall 15311 of the groove.

[0058] In other embodiments, different welding strategies can be used to achieve electrical connection. For example, the outer edge region of the current collector 130 can be welded to the tab stack 1218, and the central region of the current collector 130 can be welded to the bottom wall 15311 of the groove, thereby establishing a conductive path between the current collector 130, the tab stack 1218, and the electrode terminal 150.

[0059] In one embodiment of this utility model, please refer to Figure 2 On the side of the electrode assembly 120 facing the electrode terminal 150, both the positive electrode active material layer 1212 and the separator 123 of the positive electrode sheet 121 have end faces close to the electrode terminal 150. The end faces of the positive electrode sheet 121 and / or the end faces of the separator 123 form a positive terminal face 12171 facing the electrode tab stack portion 1218. An axial gap B1 is formed between the positive terminal face 12171 and the protrusion 146. It should be noted that, in this embodiment, the positive terminal face 12171 specifically refers to the end face of the inner ring portion of the core that is closest to the protrusion 146 in the axial direction. In one embodiment, the positive terminal face 12171 may be formed by the end face of the positive electrode active material layer 1212 extending beyond the end face of the separator 123. In another embodiment, the positive terminal face 12171 may also be formed by the end face of the separator 123 extending beyond the end face of the positive electrode active material layer 1212. In some other embodiments, the end face of the positive electrode active material layer 1212 may be flush with the end face of the separator 123, together forming the positive electrode surface 12171. It should be noted that the axial gap B1 formed between the positive electrode surface 12171 and the protrusion 146 specifically refers to the distance between the end of the protrusion 146 with the largest radial dimension facing the electrode assembly 120 and the positive electrode surface 12171 along the axial direction of the housing 110.

[0060] In this embodiment, by forming an axial gap B1 between the positive terminal face 12171 and the protrusion 146, the probability of interference between the protrusion 146 and the positive terminal face 12171 in the axial direction can be reduced. This design helps to reduce the compression of the separator 123 or positive electrode plate 121 on the positive terminal face 12171 during the installation of the filler plug 140, thereby reducing the risk of internal short circuit due to contact and effectively suppressing the occurrence of positive and negative short circuits. Therefore, this structure is beneficial to improving the safety performance of the cylindrical battery 100.

[0061] Please see Figure 2 In one embodiment of this utility model, along the axial direction of the cylindrical battery 100, from the electrode assembly 120 to the electrode terminal 150, the end face of the separator 123 extends beyond the end face of the positive electrode 121, forming a positive terminal face 12171. For ease of description, in this embodiment, the end face of the separator 123 is defined as the separator end face 1231, and the end face of the positive electrode active material layer 1212 is defined as the electrode end face 1219. With this configuration, when the liquid injection plug 140 is installed in the first through hole 151, its protrusion 146 is axially close to the separator end face 1231 and relatively far away from the electrode end face 1219. This configuration reduces the risk of the protrusion 146 contacting and pressing against the electrode end face 1219, thereby reducing the risk of internal short circuits caused by the positive electrode 121 contacting the negative electrode 122 due to pressure deformation, thus improving the safety and reliability of the cylindrical battery 100.

[0062] Please see Figures 4 to 6 In one embodiment of this utility model, at least a portion of the uncoated portion is coated with an insulating layer. The insulating layer has an end face near the electrode terminal 150, and the end face of the insulating layer forms the end face of the positive electrode 121, i.e., forms the electrode end face 1219. The insulating layer can be a ceramic insulating layer, a silicone insulating layer, etc. For example, in this embodiment, the insulating layer is a ceramic insulating layer 126. Along the axial direction of the cylindrical battery 100, the end face of the positive electrode 121 extends beyond the end face of the separator 123 to form a positive terminal end face 12171. By providing an insulating layer and having its end face extend beyond the end face of the separator 123, the protruding end 141 can be positioned closer to the electrode end face 1219 in the axial direction, while being relatively farther away from the separator end face 1231. This reduces the risk of the protruding end 141 contacting or even pressing against the separator end face 1231, helping to ensure the structural integrity and normal function of the separator 123.

[0063] It should be noted that the ceramic insulating layer 126 is mainly a coating formed by mixing ceramic material (such as alumina) with a binder, and its function is insulation and protection. In the wound electrode assembly 120 core, the edges of the electrode sheets are areas of stress concentration and prone to displacement. Exposed metal current collectors are at risk of internal short circuits caused by burrs or impacts to the opposite electrode sheets. Because the ceramic insulating layer 126 has excellent insulation and high heat resistance, its placement in the corresponding areas can reduce the risk of such short circuits and improve the safety and reliability of the cylindrical battery 100. Simultaneously, due to the certain hardness of the ceramic insulating layer 126, its placement allows the positive electrode sheet 121 facing the separator 123 to maintain a relatively stable vertical position. This provides better support and positioning for the separator 123, further ensuring its normal operation within the cylindrical battery 100.

[0064] Additionally, please see Figure 5 By extending the end face of the ceramic insulating layer 126 beyond the end face of the diaphragm 123, the positive electrode tab 1214 can form a stable tab protrusion structure above the diaphragm 123 with the help of the ceramic insulating layer 126 when bent. This structure improves the support strength of the positive electrode tab 1214 at the bend root, reducing the possibility of displacement at the bend root, thereby improving the forming accuracy and structural stability of the tab stack 1218, reducing its dimensional fluctuations in the radial direction of the housing 110, and further reducing the risk of radial interference with the protrusion 146. Furthermore, the ceramic insulating layer 126 helps ensure the consistency of the bending shape of the positive electrode tab 1214, further ensuring the dimensional accuracy of the tab stack 1218. In addition, this structure can prevent the bent root of the positive electrode tab 1214 from contacting the lower diaphragm 123, thereby reducing the transfer of heat generated at the bent root of the positive electrode tab 1214 to the diaphragm 123, thus reducing the probability of heat loss in the diaphragm 123.

[0065] Please see Figure 6 and Figure 7In one embodiment of this utility model, the diameter of the core through hole 124 is d1, the maximum radial dimension of the protrusion 146 is d2, and d1≥d2. The extension height of the positive electrode tab 1214 of the positive electrode sheet 121 is a, a≤(n-1)×(c+f+h), where n is the number of turns after the positive electrode sheet 121 is wound in the winding head region 1215, c is the thickness of the positive electrode sheet 121, f is the thickness of the negative electrode sheet 122, and h is the thickness of the diaphragm 123. Since the diameter d1 of the core through hole 124 is greater than the maximum radial dimension d2 of the protrusion 146, it is only necessary to ensure that the side of the tab stack 1218 facing the core through hole 124 does not block the core through hole 124 in the radial direction to avoid contact interference between the tab stack 1218 and the protrusion 146 of the injection plug 140. The tab stack 1218 is formed by stacking and bending the positive tabs 1214 in the radial direction. Therefore, as long as the innermost positive tab 1214 (i.e., the positive tab 1214 closest to the inner core) does not block the core through hole 124 after bending, the entire tab stack 1218 can be ensured not to block the core through hole 124. Please refer to [link to relevant documentation]. Figure 7 For ease of description, the innermost positive electrode tab 1214 is defined as the initial positive electrode tab 12141. Please refer to... Figure 9 To ensure that the initial positive electrode tab 12141 does not obstruct the core through hole 124 after bending, the radial dimension of the inner ring portion of the core must be greater than the unfolded height a of the initial positive electrode tab 12141. The radial width of the inner ring portion of the core is denoted as b.

[0066] The radial width b of the inner ring portion of the core is related to the number of turns of the positive electrode 121 after winding the head region 1215, the thickness of the positive electrode 121, the negative electrode 122, and the diaphragm 123, specifically satisfying: b = (n-1) × (c + f + h). Therefore, it can be deduced that when a ≤ (n-1) × (c + f + h), it can be ensured that the electrode tab stack 1218 does not interfere with the protrusion 146 of the liquid injection plug 140 in the radial direction.

[0067] Please see Figure 2 and Figure 7, in an embodiment of the present utility model, the diameter of the core through-hole 124 is d1, the maximum radial dimension of the protrusion 146 is d2, and d1 < d2; the extension height of the positive electrode tab 1214 of the positive electrode sheet 121 is a, and a ≤ (n - 1) × (c + f + h) - (d2 - d1) / 2, where n is the number of winding turns after winding the first region 1215 of the positive electrode sheet 121, c is the thickness of the positive electrode sheet 121, f is the thickness of the negative electrode sheet 122, and h is the thickness of the separator 123. Since the diameter d1 of the core through-hole 124 is smaller than the maximum radial dimension d2 of the protrusion 146, in order to avoid contact interference between the tab stacking portion 1218 and the protrusion 146 of the liquid injection plug 140, it is necessary to ensure that, in the radial direction, the side of the tab stacking portion 1218 facing the core through-hole 124 does not contact the maximum radial dimension portion of the protrusion 146. According to the derivation logic of the foregoing embodiment, as long as it is ensured that the innermost positive electrode tab 1214 (i.e., the positive electrode tab 1214 of the inner ring portion close to the core) does not block the core through-hole 124 after being bent, it can be ensured that the entire tab stacking portion 1218 will not block the core through-hole 124. To achieve this condition, the extension height a of the initial positive electrode tab 12141 should be less than the radial distance from the outer peripheral edge of the inner ring portion of the core (i.e., the side of the positive electrode end 1217 away from the core through-hole 124 in the radial direction) to the maximum radial dimension portion of the protrusion 146. Denote this radial distance as g, that is, it is necessary to satisfy a < g. The distance g is related to the width of the positive electrode end 1217 in the radial direction, the diameter d1 of the core through-hole 124, and the maximum radial dimension d2 of the protrusion 146, and specifically satisfies: g = b - (d2 - d1) / 2. At the same time, according to the previous embodiment, the width b of the inner ring portion of the core in the radial direction satisfies: b = (n - 1) × (c + f + h). Substituting the above relationship, it can be deduced that when satisfying: a ≤ (n - 1) × (c + f + h) - (d2 - d1) / 2, it can be ensured that the tab stacking portion 1218 does not have contact interference with the protrusion 146 of the liquid injection plug 140 in the radial direction.

[0068] It should be noted that all length dimension parameters (a, b, c, h, f, g, d1, and d2) in the above formula use the same unit, such as millimeters (mm) or micrometers (μm).

[0069] Please refer to Figure 8 and Figure 9 , in an embodiment of the present utility model, the protruding end 141 further has a recessed portion 142, and the recessed portion 142 is located on the side of the protrusion 146 away from the electrode assembly 120. The recessed portion 142 corresponds to the first through-hole 151 and is compressed at the first through-hole 151 to achieve sealing relative to the first through-hole 151. At least part of the recessed portion 142 and / or the protrusion 146 abuts against the inner wall of the second through-hole 131 in the circumferential direction. Please refer to Figure 9The diameter of the first through hole 151 is d3, and the diameter of the second through hole 131 is d4, where d3 < d4 < d2. In one embodiment, at least a portion of the recess 142 may abut against the wall of the second through hole 131 in the circumferential direction. In another embodiment, at least a portion of the protrusion 146 may abut against the wall of the second through hole 131 in the circumferential direction. In other embodiments, both the outer peripheral surface of a portion of the recess 142 and the outer peripheral surface of a portion of the protrusion 146 may abut against the wall of the second through hole 131 in the circumferential direction.

[0070] The edge of the first through hole 151 is provided with a rounded corner 1511, and the recessed portion 142 at least partially abuts against the rounded corner 1511. The rounded corner 1511 may be provided only on the side of the first through hole 151 facing the second through hole 131, or only on the side of the first through hole 151 away from the second through hole 131, or rounded corners 1511 may be provided on both sides of the first through hole 151. By providing a rounded corner 1511 at the edge of the first through hole 151, the risk of the recessed portion 142 of the injection plug 140 being scratched or worn when in contact with the first through hole 151 can be reduced. At the same time, it is also beneficial to guide the recessed portion 142 to be smoothly installed, improving the smoothness of assembly and the reliability of the sealing connection.

[0071] The above structure not only achieves a reliable seal between the protruding end 141 and the first through hole 151, but also effectively increases the sealing contact area of ​​the injection plug 140 by utilizing the abutment between the recessed portion 142 or the protruding portion 146 on the protruding end 141 and the side wall 113 of the second through hole 131, thereby further improving its overall sealing performance. On the other hand, in terms of dimensional relationships, since d3 < d4 < d2, this configuration can enhance the radial restraint and stop effect of the second through hole 131 on the protruding portion 146, significantly increasing the resistance required for the injection plug 140 to dislodge from the first through hole 151, thereby helping to enhance the pressure resistance and reliability of the sealing connection between the injection plug 140 and the housing 110.

[0072] Please see Figure 10 The depth of the first through hole 151 along the axial direction of the cylindrical battery 100 is H1, and H1 ≥ 2mm. Since the first through hole 151 penetrates the bottom wall 15311 of the groove, this depth H1 is the thickness h1 of the bottom wall 15311 of the groove. By setting the thickness h1 of the bottom wall 143 to not less than 2mm, on the one hand, it can be ensured that the liquid injection plug 140 inserted in the first through hole 151 has sufficient sealing contact area with the first through hole 151, thereby effectively improving the sealing performance; on the other hand, this thickness design can ensure that the bottom wall 15311 of the groove has the necessary mechanical strength and rigidity, so that it can reliably resist internal pressure changes during the charging and discharging process of the cylindrical battery 100 and meet the pressure resistance requirements of the cylindrical battery 100.

[0073] Please see Figure 11 In an embodiment of the present utility model, along the axial direction of the cylindrical battery 100, the distance between the convex portion 146 and the current collector member 130 is H2, and 0 < H2 ≤ B1. The protruding end 141 has a bottom wall 143 close to the electrode assembly 120, the bottom wall 143 is a planar structure, and the outer peripheral edge of the bottom wall 143 is connected to the outer peripheral surface of the convex portion 146. It should be noted that the distance H2 specifically refers to the axial spacing between the end of the convex portion 146 far from the first through hole 151 and the surface of the current collector member 130 facing the tab stacking portion 1218. In this embodiment, by limiting the distance H2 within the range of 0 < H2 ≤ B1, it can be ensured that the convex portion 146 is arranged closer to the current collector member 130 axially. This dimensional constraint can effectively prevent the size of the protruding end 141 extending into the internal accommodation space 114 of the cylindrical battery 100 from being too long due to the excessive distance between the concave portion 142 and the convex portion 146. This can not only further reduce the probability that the convex portion 146 extends to the area below the tab stacking portion 1218 and contacts the electrode plate or separator 123 at the positive terminal 1217, but also avoid the protruding end 141 of the liquid injection plug 140 occupying too much axial height space, thereby being beneficial to reducing the impact on the volumetric energy density of the cylindrical battery 100. At the same time, since the outer peripheral edge of the bottom wall 143 is connected to the outer peripheral surface of the convex portion 146, this not only helps to reduce the space occupied by the protruding end 141 axially, thereby reducing the possibility of contact or interference between the protruding end 141 and the electrode assembly 120. Moreover, on the basis of ensuring that the overall height of the protruding end 141 does not increase, the structural proportion of the convex portion 146 on the protruding end 141 can be further enhanced, which is more beneficial to the stability and reliability of the installation of all the liquid injection plugs 140.

[0074] In an embodiment of the present utility model, the cylindrical battery 100 includes: a housing 110, an electrode terminal 150, an electrode assembly 120, and a liquid injection plug 140. An accommodation space 114 is formed inside the housing 110. The electrode terminal 150 is fixedly arranged on the housing 110 and insulated from the housing 110, and has a first through hole 151 communicating with the accommodation space 114. The electrode assembly 120 is accommodated in the accommodation space 114. The electrode assembly 120 has a positive terminal 1217 and a negative terminal arranged opposite to each other along the axial direction of the electrode assembly 120. The positive terminal 1217 is arranged opposite to the electrode terminal 150 and electrically connected. The electrode assembly 120 has a core through hole 124 penetrating the electrode assembly 120 along the axial direction of the electrode assembly 120. The negative terminal is arranged on the side of the electrode assembly 120 away from the electrode terminal 150 and electrically connected to the housing 110. The electrode assembly 120 includes the core through hole 124 and the positive terminal 1217 in the above embodiments. It should be noted that in this embodiment, the specific structures of the housing 110, the electrode terminal 150, and the electrode assembly 120 can refer to the relevant structure introductions in the above embodiments, and will not be repeated here.

[0075] The injection plug 140 is installed in the first through hole 151 and includes a protruding end 141 extending toward the receiving space 114. The protruding end 141 has a raised portion 146 that protrudes radially along the electrode assembly 120. Specifically, the raised portion 146 protrudes radially outward relative to the first through hole 151. The raised portion 146 may be an annular raised structure surrounding the first through hole 151, or it may be a plurality of spaced local raised points, etc. Optionally, in this embodiment, the raised portion 146 is an annular raised structure surrounding the first through hole 151.

[0076] The specific position of the injection plug 140 and the core through hole 124 is not limited. The injection plug 140 can be coaxially or non-coaxially arranged with the core through hole 124, as long as it meets the injection position requirements of the electrode assembly 120. Along the axial direction of the cylindrical battery 100, at least a portion of the projection of the core through hole 124 falls within the projection of the protruding end 141. In one embodiment, when the diameter of the core through hole 124 is smaller than the outer diameter of the projected contour of the protruding end 141, and the protruding end 141 and the core through hole 124 are substantially coaxially arranged, the projection of the core through hole 124 can completely fall within the projection of the protruding end 141. In another embodiment, when the diameter of the core through hole 124 is smaller than the outer diameter of the projected contour of the protruding end 141, and the core through hole 124 and the protruding end 141 are non-coaxially arranged, the projection of the core through hole 124 can only partially fall within the projection of the protruding end 141.

[0077] Please see Figure 12 At least partially near the positive end 1217 of the core through hole 124, the electrode assembly extends radially toward the core through hole 124 and gradually slopes away from the electrode terminal 150, forming an inclined end face 125. This inclined end face 125 is an annular structure surrounding the axis of the core through hole 124. The protruding end 141 has a bottom wall 143 near the electrode assembly 120, and the protruding portion 146 has an annular inclined wall 1461 connecting to the bottom wall 143. The annular inclined wall 1461 is inclined in the same direction as the inclined end face 125 and is disposed opposite to it, with a gap A formed between the annular inclined wall 1461 and the inclined end face 125.

[0078] The annular inclined wall 1461 and the inclined end face 125 extend in the same direction and are arranged opposite each other. Specifically, the annular inclined wall 1461 and the inclined end face 125 extend in the same direction and are arranged opposite each other in space, either parallel or approximately parallel. A gap A is formed between the annular inclined wall 1461 and the inclined end face 125. Specifically, a gap A is formed between the annular inclined wall 1461 and the inclined end face 125 along the circumference of the core through hole 124, meaning that the annular inclined wall 1461 and the inclined end face 125 do not contact each other in the circumferential direction. Gap A refers to the vertical distance between the oppositely arranged annular inclined wall 1461 and the inclined end face 125.

[0079] In this embodiment, the specific size of the gap A is not strictly limited. As an optional solution, in one implementation, the size of the gap A is usually set to 1.5 to 2 times the thickness of the diaphragm 123. For example, if the thickness of the diaphragm 123 is 10 μm, then A ≈ 15 to 20 μm.

[0080] In this embodiment, an annular inclined wall 1461 is provided at the protruding end 141 of the liquid injection plug 140 extending into the housing 110. The annular inclined wall 1461 is positioned opposite to and extends in the same direction at an inclined end face 125 of the electrode assembly 120 facing the electrode terminal 150, and a gap A is formed between them. At least a portion of the projection of the core through hole 124 falls within the projection of the protruding end 141. With this configuration, since the annular inclined wall 1461 and the inclined end face 125 can form an effective physical clearance space through their relative inclined structure, it can reduce the probability of contact between the liquid injection plug 140 and the electrode assembly 120, while keeping the installation height of the liquid injection plug 140 and the electrode assembly 120 unchanged. This can further reduce the probability of internal short circuit caused by contact between the positive electrode 121 and the negative electrode 122, thereby improving the safety and reliability of the cylindrical battery 100. Simultaneously, this allows the liquid injection plug 140 to be positioned closer to the core through hole 124, thereby reducing the occupied height space of the casing 110 and improving the volumetric energy density of the cylindrical battery 100. Furthermore, the gap A also provides space for the shrinkage of the separator 123 during the charging and discharging of the electrode assembly 120, preventing the normal use of the separator 123 from being affected by the compression of the electrode assembly 120 by the liquid injection plug 140.

[0081] It should be noted that, based on the gap A provided in this embodiment, the following dimensional relationships can be further satisfied: the minimum radial distance between the tab stack 1218 and the first through hole 151 is L, and the radial distance from the maximum radial dimension of the protrusion 146 to the first through hole 151 is W, satisfying 0 < W < L. This dimensional constraint helps to avoid contact or interference between the tab stack 1218 and the protrusion 146 in the radial direction. Of course, if the radial interference problem between the tab stack 1218 and the protrusion 146 does not need to be considered, in other embodiments, only the gap A can be provided without specifically limiting the distance W.

[0082] Please see Figure 12 and Figure 14 In one embodiment of this utility model, the liquid injection plug 140 includes a rotation axis 1401, and the angle between the annular inclined wall 1461 and the rotation axis 1401 is θ, which satisfies 5°≤θ≤30°. For example, θ can be 5°, 15°, or 30°. The setting of this angle θ needs to comprehensively consider the feasibility of the actual structural design of the cylindrical battery 100 and the stability and reliability of the liquid injection plug 140 installed in the first through hole 151. Specifically, setting the angle θ to not less than 5° can ensure that a necessary gap A is maintained between the liquid injection plug 140 and the inclined end face 125, thereby providing sufficient deformation freedom for the separator 123 and the electrode during charging and discharging, reducing the risk of short circuit between the positive and negative electrodes due to the liquid injection plug 140 squeezing the separator 123 or the electrode, or affecting the normal use of the separator 123. On the other hand, limiting the included angle θ to no more than 30° can avoid excessive reduction in the structural strength of the protrusion 146 due to an excessively large angle, ensuring that the protrusion 146 has sufficient structural strength and a stopping function, thereby reducing the probability of the injection plug 140 falling out of the first through hole 151.

[0083] The process of determining the angle θ between the annular inclined wall 1461 and the axis of rotation 1401 is explained. Since the annular inclined wall 1461 and the inclined end face 125 are arranged parallel to each other, the process of determining the angle θ is essentially the process of determining the inclination angle of the inclined end face 125 on the electrode assembly 120. Under the condition that there is a target gap A between the inclined end face 125 and the annular inclined wall 1461, the angle θ on the inclined end face 125 side can be calculated by the following formula: tanθ=(ΔL+A) / H, where H represents the projected height of the inclined end face 125 in the axial direction of the cylindrical battery 100, a value determined by the process control parameters during the forming process of the inclined end face 125. ΔL is the projected width of the inclined end face 125 in the radial direction of the cylindrical battery 100, a dimension that depends on the number of turns of the core corresponding to the inclined end face 125 region, the thickness of the winding unit, and the winding tightness of the core. Specifically, the thickness of the winding unit refers to the sum of the thicknesses of the positive electrode 121, the negative electrode 122, and the separator 123. It should be noted that the thickness h of the separator 123 includes its initial thickness and compressive modulus. The target gap A is typically set to 1.5 to 2 times the thickness h of the separator 123; for example, if the thickness of the separator 123 is 10 μm, then A is approximately 15 to 20 μm. Based on these parameters, the slope θ can be determined using the following mathematical formula: tanθ = (ΔL + A) / H. According to actual electrode assembly design experience, an angle θ within the range of 5° to 30° is generally suitable. Setting the lower limit of the angle θ to 5° ensures that the minimum gap A can meet the degrees of freedom required for the full charging process of the separator 123, ensuring the normal operation of the separator 123. Setting the upper limit of the included angle θ to 30° helps maintain the structural strength of the protrusion 146 of the injection plug 140, preventing the injection plug 140 from falling out due to insufficient installation strength at the first through hole 151 caused by an excessive tilt angle. It should be noted that in the above formula tanθ=(ΔL+A) / H, all length dimension parameters (ΔL, A, H) use the same unit (e.g., millimeters mm, micrometers μm).

[0084] Please see Figure 12 In one embodiment of the present invention, the tab stack 1218 extends at least partially between the inner ring portion of the core facing the electrode terminal 150 and the electrode terminal 150. Along the direction from the electrode assembly 120 to the electrode terminal 150, the end of the diaphragm 123 near the electrode terminal 150 extends beyond the end of the positive electrode sheet 121 near the electrode terminal 150, and forms a diaphragm end face 1231 facing the tab stack 1218. A portion of the diaphragm end face 1231 forms an inclined end face 125. Specifically, the diaphragm end face 1231 near the core through hole 124 forms an inclined end face 125.

[0085] With this configuration, when the injection plug 140 is installed in the first through hole 151, its protruding end 141 is positioned axially close to the separator 123, and relatively far away from the positive electrode 121 and the negative electrode 122. This configuration reduces the risk of the protruding end 141 coming into contact with and pressing against the positive electrode 121 and the negative electrode 122, thereby reducing the risk of internal short circuits caused by contact between the positive electrode 121 and the negative electrode 122. Simultaneously, since the inclined end face 125 is made of insulating separator 123 material, even if the protruding end 141 comes into contact with the separator end face 1231 during assembly or operation, it will not cause an internal short circuit, thus improving the safety and reliability of the cylindrical battery 100.

[0086] Please see Figure 12 In one embodiment of this utility model, along the axial direction of the cylindrical battery 100, the projected profile of the tab stack 1218 includes an inner edge 12181, and the projected profile of the inclined end face 125 includes an outer edge 1251. The inner edge 12181 of the projected profile of the tab stack 1218 is located on the outer periphery of the outer edge 1251 of the projected profile of the inclined end face 125, and a gap B is formed between them. Axially, the tab stack 1218 is positioned closer to the protrusion 146 of the filler plug 140 than the positive end 1217 of the winding core. Because the protrusion 146 has a larger diameter, radial contact is more easily achieved between the tab stack 1218 and the protrusion 146. Therefore, in this embodiment, by placing the inner edge 12181 of the projected profile of the tab stack 1218 on the outer periphery of the outer edge 1251 of the projected profile of the inclined end face 125, and forming a gap B between them, it can be ensured that the inner edge 12181 of the tab stack 1218 does not extend into the projected area of ​​the inclined end face 125 in the radial direction, thereby making the tab stack 1218 further away from the protrusion 146 in the radial direction. This reduces the probability of the tab stack 1218 contacting the protrusion 146 in the radial direction, thereby further reducing the risk of short circuit caused by contact between the positive electrode 121 and the negative electrode 122.

[0087] Please see Figure 13In one embodiment of this utility model, the tab stack 1218 extends at least partially between the inner ring portion of the core facing the electrode terminal 150 and the electrode terminal 150. At least a portion of the uncoated portion 1213 near the positive electrode active material layer 1212 is coated with an insulating layer. The insulating layer can be a ceramic insulating layer, a rubber insulating layer, etc. Exemplarily, in this embodiment, the insulating layer is a ceramic insulating layer 126. The specific material and function of the ceramic insulating layer 126 can be referred to the description of the ceramic insulating layer 126 in the above embodiments, and will not be repeated here. Along the direction from the electrode assembly 120 to the electrode terminal 150, one end of the ceramic insulating layer 126 near the electrode terminal 150 extends beyond the side of the diaphragm 123 near the electrode terminal, forming an electrode end face 1219 facing the tab stack 1218, and a portion of the electrode end face 1219 forms an inclined end face 125. Specifically, the electrode end face 1219 near the core through hole 124 forms an inclined end face 125.

[0088] In this embodiment, by setting the end of the ceramic insulating layer 126 near the electrode terminal 150 to extend beyond the end of the separator 123 near the electrode terminal 150, the protruding end 141 is positioned axially closer to the electrode end face 1219 and relatively farther from the separator end face 1231. This reduces the risk of the protruding end 141 contacting or even pressing against the separator 123, thus helping to ensure the structural integrity and normal function of the separator 123. Furthermore, the ceramic coating 126 maintains a high degree of flatness and stability in the area of ​​the positive electrode 121 facing the separator 123, providing better support and positioning for the separator 123, further ensuring its proper use within the cylindrical battery 100.

[0089] Please see Figure 15 In one embodiment of this utility model, a stop portion 145 is connected to the side of the protruding end 141 facing away from the electrode assembly 120. The stop portion 145 is located outside the first through hole 151 and abuts against the outer periphery of the first through hole 151. The protruding end 141 is also provided with a recessed portion 142, which is located on the side of the protruding portion 146 facing away from the electrode assembly 120. The recessed portion 142 is provided corresponding to the first through hole 151 and is compressed at the first through hole 151 to achieve a seal relative to the first through hole 151. The columnar portion 153 of the electrode terminal 150 is provided with a groove portion 1531 exposing the first through hole 151 on the side facing away from the receiving space 114. The groove portion 1531 includes a groove bottom wall 15311, and the first through hole 151 is disposed on the groove bottom wall 15311. A cover plate 155 is fitted to the groove portion 1531, and the cover plate 155 seals the groove portion 1531. In this embodiment, the specific structure of the electrode terminal 150 can be referred to the description of the electrode terminal 150 in the above embodiment, and will not be repeated here.

[0090] In this embodiment, by providing a stop portion 145, a recessed portion 142, and a protrusion 146, and by placing the recessed portion 142 in a compressed state at the first through hole 151, reliable axial positioning of the injection plug 140 is achieved. Specifically, the cooperation between the stop portion 145 and the protrusion 146 effectively constrains the axial displacement of the injection plug 140, thereby maintaining the stability of the installation position between the recessed portion 142 and the first through hole 151 and enhancing the reliability of the sealing structure at this position. Simultaneously, by adding a cover plate 155 to seal the groove portion 1531, a secondary sealing guarantee can be provided in case of seal failure between the injection plug 140 and the first through hole 151, further reducing the risk of leakage at the first through hole 151 and improving the overall sealing reliability of the electrode terminal 150 side.

[0091] Please see Figure 13 and Figure 14 In one embodiment of this utility model, the bottom wall 143 of the protruding end 141 is flat, and the bottom wall 143 is provided with a first recess 144 recessed towards the electrode terminal 150. The shape of the first recess 144 can be hemispherical, conical, or any other recessed structure. The first recess 144 can be located in the central region of the bottom wall 143 or it can be located off-center. To facilitate the forming and positioning of the first recess 144 on the bottom wall 143, optionally, in this embodiment, the first recess 144 is located in the central region of the bottom wall 143, and the first recess 144 is an approximately hemispherical structure. Because gas is generated inside the cylindrical battery 100 during charging and discharging, the internal pressure of the casing 110 increases. Under the action of this internal pressure, the bottom wall 143 of the protruding end 141 will be subjected to an outward thrust. By providing a first recess 144 in the bottom wall 143, a gas storage or pressure relief space can be formed inside the housing 110, thereby effectively reducing the thrust of the internal pressure on the bottom wall 143 and reducing the probability of the injection plug 140 coming out of the first through hole 151.

[0092] Please see Figure 15In one embodiment of this utility model, a stop portion 145 is connected to the side of the protruding end 141 facing away from the electrode assembly 120. The stop portion 145 is located outside the first through hole 151 and abuts against the outer periphery of the first through hole 151. The protruding end 141 is also provided with a recessed portion 142, which is located on the side of the protruding portion 146 facing away from the electrode assembly 120. The recessed portion 142 is provided corresponding to the first through hole 151 and is compressed at the first through hole 151 to achieve a seal relative to the first through hole 151. The columnar portion 153 of the electrode terminal 150 is provided with a groove portion 1531 exposing the first through hole 151 on the side facing away from the receiving space 114. The groove portion 1531 includes a groove bottom wall 15311, and the first through hole 151 is disposed on the groove bottom wall 15311. A cover plate 155 is fixedly connected to the side of the columnar portion 153 facing away from the electrode assembly 120, and the cover plate 155 seals the groove portion 1531. In this embodiment, the specific structure of the electrode terminal 150 can be referred to the description of the electrode terminal 150 in the above embodiments, and will not be repeated here.

[0093] In this embodiment, by providing a stop portion 145, a recessed portion 142, and a protrusion 146, and by placing the recessed portion 142 in a compressed state at the first through hole 151, reliable axial positioning of the injection plug 140 is achieved. Specifically, the cooperation between the stop portion 145 and the protrusion 146 effectively constrains the axial displacement of the injection plug 140, thereby maintaining the stability of the installation position between the recessed portion 142 and the first through hole 151 and enhancing the reliability of the sealing structure at this position. Simultaneously, by adding a cover plate 155 to seal the groove portion 1531, a secondary sealing guarantee can be provided in case of seal failure between the injection plug 140 and the first through hole 151, further reducing the risk of leakage at the first through hole 151 and improving the overall sealing reliability of the electrode terminal 150 side.

[0094] Please see Figure 15In one embodiment of this utility model, a second recess 1451 is provided on the side of the stop portion 145 facing away from the electrode assembly 120, and the second recess 1451 is recessed towards the side of the protruding end 141. The shape of the second recess 1451 is not limited, and it can be any recessed structure such as a hemispherical shape or a conical shape. The second recess 1451 can be provided in the central area of ​​the stop portion 145, or it can be provided off-center from the central area of ​​the stop portion 145. In order to facilitate the positioning and processing of the second recess 1451 on the stop portion 145, optionally, in this embodiment, the second recess 1451 is provided in approximately the central area of ​​the stop portion 145. By providing the second recess 1451, when picking up or putting down the injection plug 140, the operator can insert a gripping tool (such as tweezers) into the second recess 1451, thereby obtaining a stable gripping force point, which facilitates reliable gripping of the injection plug 140. Meanwhile, the structural design of the second recess 1451 helps the gripping tool to be quickly positioned and locked in place, reducing the time required for adjustment and alignment, and improving the efficiency of picking up and putting down the injection plug 140.

[0095] Please see Figure 15 In one embodiment of this utility model, the diameter of the core through hole 124 is d1, the maximum radial dimension of the protrusion 146 is d2, and d2 > d1; the diameter of the first through hole 151 is d3, and d2 > d3. In this structural design, the smaller diameter d1 of the core through hole 124 helps to reduce energy density loss at the core through hole 124, thereby improving the overall energy density of the cylindrical battery 100. Since the maximum radial dimension d2 of the protrusion 146 is greater than the diameter d3 of the first through hole 151, this arrangement ensures the stability and sealing reliability of the liquid injection plug 140 on the electrode terminal 150. At the same time, due to the dimensional relationship that d2 is greater than d1, the combination of the annular inclined wall 1461 on the protrusion 146 and the inclined end face 125 on the core can more effectively avoid contact interference between the liquid injection plug 140 and the electrode assembly 120 during the assembly process, thereby reducing the risk of internal short circuits and improving the safety and reliability of the cylindrical battery 100.

[0096] Please see Figure 16 In one embodiment of the battery pack 200 of this utility model, the battery pack 200 includes a housing 210 and at least one cylindrical battery 100. The housing 210 includes a first housing portion 211 and a second housing portion 212, which cover each other to form a receiving space. Multiple cylindrical batteries 100 are housed within the receiving space, and the multiple cylindrical batteries 100 can be connected in series and / or in parallel. The battery pack 200 can be, for example, a battery module, a battery pack, etc.

[0097] Please see Figure 17In one example of the electronic device 300 of this utility model, the electronic device 300 includes a working part 310 and a battery pack 200. The working part 310 is electrically connected to the battery pack 200 to obtain electrical power. The working part 310 can be a unit component capable of obtaining electrical power from the battery pack 200 and performing corresponding work, such as a fan blade rotation unit, a vacuum cleaner suction unit, or a wheel drive unit in an electric vehicle. The electronic device 300 can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship 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 utility model embodiment does not impose special limitations on the above-mentioned electronic device 300. In one embodiment of the electronic device 300 of this utility model, the electronic device 300 is a vehicle, the working part 310 is the vehicle body, and the battery pack 200 is fixedly installed on the vehicle body, thereby providing driving force for the vehicle to operate.

[0098] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A cylindrical battery, characterized by comprising: include: The shell has an internal space for containment. The electrode terminal is fixedly disposed in the housing and insulated from the housing, and has a first through hole communicating with the receiving space; An electrode assembly is housed within the receiving space. The electrode assembly has a positive terminal and a negative terminal arranged opposite to each other along the axial direction of the electrode assembly. The positive terminal is arranged opposite to and electrically connected to the electrode terminal. The electrode assembly has a core through hole that extends through the electrode assembly along the axial direction of the electrode assembly. The liquid injection plug is installed in the first through hole and includes a protruding end extending toward the receiving space. The protruding end has a protrusion that protrudes radially along the electrode assembly, and at least a portion of the projection of the core through hole falls within the projection of the protruding end along the axial direction. At least a portion of the positive end near the core through hole extends gradually in a tilted manner away from the electrode terminal along the radial direction of the electrode assembly toward the core through hole and forms a tilted end face; the protruding end has a bottom wall near the electrode assembly, the protruding portion has an annular inclined wall connecting the bottom wall, the annular inclined wall and the tilted end face extend in the same direction and are disposed opposite to each other, and a gap A is formed between the annular inclined wall and the tilted end face.

2. The cylindrical battery according to claim 1, characterized by The injection plug includes a rotation axis, and the angle between the annular inclined wall and the rotation axis is θ, where 5°≤θ≤30°.

3. The cylindrical battery according to claim 2, characterized by The electrode assembly includes a positive electrode, a negative electrode, and a separator separating the positive and negative electrode. The positive electrode, the negative electrode, and the separator are stacked and wound to form a core. The core includes a through hole. The positive electrode includes a positive current collector and a positive active material layer coated on the positive current collector. The positive current collector also includes an uncoated portion that is not coated with the positive active material layer. At least a portion of the uncoated portion forms a positive electrode tab, which is electrically connected to the electrode terminal. The positive electrode includes a beginning region located at the beginning of the winding and a middle region connected to the beginning region. The uncoated portion located in the beginning region does not have the positive electrode tab. The beginning region is wound to form the inner ring portion of the core. The positive electrode tabs of the uncoated portion located in the central region are bent toward the central axis of the electrode assembly and stacked to form an electrode tab stack, which is welded to the electrode terminal. The tab stack extends at least partially between the inner ring portion of the core and the electrode terminal on the side facing the electrode terminal; along the direction from the electrode assembly to the electrode terminal, the end of the diaphragm near the electrode terminal extends beyond the end of the positive electrode sheet near the electrode terminal and forms a diaphragm end face, a portion of the diaphragm end face forming the inclined end face.

4. The cylindrical battery according to claim 3, characterized by Along the axial direction, the inner edge of the projection profile of the tab stack is located on the outer periphery of the outer edge of the projection profile of the inclined end face, and a gap B is formed between them.

5. The cylindrical battery according to claim 3, wherein The electrode stack extends at least partially between the inner ring portion of the core facing the electrode terminal and the electrode terminal; at least a portion of the uncoated portion is coated with an insulating layer, and along the direction from the electrode assembly to the electrode terminal, one end of the insulating layer near the electrode terminal extends beyond the end of the diaphragm near the electrode terminal and forms an electrode end face, and a portion of the electrode end face forms the inclined end face.

6. The cylindrical battery according to claim 1, wherein A stop portion is connected to the side of the protruding end opposite to the electrode assembly. The stop portion is located on the side of the first through hole opposite to the electrode assembly and abuts against the outer periphery of the first through hole. The protruding end is also provided with a recessed portion, which is located on the side of the protruding portion opposite to the electrode assembly. The recessed portion is provided corresponding to the first through hole and is compressed at the first through hole to achieve a seal relative to the first through hole. The electrode terminal further includes a columnar portion and a first limiting portion and a second limiting portion respectively connected to opposite ends of the columnar portion along the axial direction. The columnar portion is installed through the housing. The first limiting portion is located within the receiving space, and the second limiting portion is located outside the housing. The columnar portion has a groove portion exposing the first through hole on the side opposite to the receiving space. The groove portion is fitted with a cover plate, and the cover plate seals the groove portion.

7. The cylindrical battery according to claim 6, characterized by The bottom wall of the protruding end is flat, and the bottom wall is provided with a first recess that is recessed toward the electrode terminal; the stop portion is provided with a second recess on the side away from the electrode assembly, and the second recess is recessed toward the side of the protruding end.

8. The cylindrical battery according to claim 1, wherein The diameter of the through hole in the core is d1, the diameter of the outer periphery of the protrusion is d2, and d2 > d1; the diameter of the first through hole is d3, and d2 > d3.

9. A battery pack characterized by comprising: The cylindrical battery includes any one of claims 1 to 8.

10. An electronic device, comprising: Includes the battery pack as described in claim 9.

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