Secondary battery, battery pack, and electronic device

Abstract

The utility model provides a secondary battery, a battery pack and an electronic device, the secondary battery comprises: a housing comprising a peripheral side wall and an end wall connected to one end of the peripheral side wall, the other end of the peripheral side wall being provided with an opening; the electrode assembly is provided with a first tab and a second tab; the pole extends to penetrate through the end wall and is insulated from the end wall; a first collector plate electrically connected to the first tab and the post; the cover plate covers the opening, and the electrode assembly is packaged by the cover plate and the shell together; and an insulating tape located between the case and the first collector plate, covering a portion of a side surface of the electrode assembly and a portion of a surface of the first collector plate facing away from the electrode assembly, in which the insulating tape has a plurality of sections in a winding direction of the electrode assembly, and two adjacent sections have an overlapping region on the surface of the first collector plate. According to the technical scheme, the safety and the energy density of the battery can be improved at least.

Description

Technical Field

[0001] The utility model relates to a secondary battery, a battery pack and an electronic device. Background Art

[0002] In the field of new energy power batteries, secondary batteries refer to rechargeable batteries, also known as renewable batteries or storage batteries. Unlike primary batteries, secondary batteries can undergo multiple charge and discharge cycles through reverse charging for reuse. Secondary batteries generally include electrode assemblies, shells, cover plates, etc. Cylindrical batteries refer to cylindrical wound core batteries, which include a shell and an electrode assembly. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator located between the positive electrode sheet and the negative electrode sheet. These positive electrode sheets, negative electrode sheets, and separators are stacked on each other and wound into an electrode assembly, which is then encapsulated in a shell. The safety and energy density of existing secondary batteries need to be further improved. Utility Model Content

[0003] In view of the problems existing in the related art, the purpose of the present invention is to provide a secondary battery, a battery pack and an electronic device, so as to at least improve the safety and energy density of the secondary battery.

[0004] To achieve the above-mentioned objectives, the present invention provides a secondary battery, which includes: a shell, including a circumferential side wall and an end wall connected to one end of the circumferential side wall, and the other end of the circumferential side wall is provided with an opening; an electrode assembly, including a first electrode sheet, a second electrode sheet and a diaphragm arranged between the first electrode sheet and the second electrode sheet, and the electrode assembly has a first electrode tab and a second electrode tab; a pole, passing through the end wall and insulated from the end wall; a first current collecting disk, electrically connected to the first electrode tab and the pole; a cover plate, covering the opening and encapsulating the electrode assembly together with the shell; and an insulating tape, located between the shell and the first current collecting disk, covering a portion of the side surface of the electrode assembly and a portion of the surface of the first current collecting disk facing away from the electrode assembly, wherein the insulating tape has multiple sections along the edge of the surface of the first current collecting disk, and two adjacent sections have overlapping areas on the surface of the first current collecting disk.

[0005] In some embodiments, at least a portion of each segment covers a portion of the surface of the first collecting disk.

[0006] In some embodiments, the area of ​​the surface of the first current collecting disk covered by the plurality of segments accounts for 30% to 99% of the orthographic projection area of ​​the surface of the first current collecting disk along a direction of the first current collecting disk toward the electrode assembly.

[0007] In some embodiments, the area of ​​the surface of the first current collecting disk covered by the plurality of segments accounts for 90%-98% of the orthographic projection area of ​​the surface of the first current collecting disk along a direction of the first current collecting disk toward the electrode assembly.

[0008] In some embodiments, a minimum thickness of the plurality of segments covering the surface of the first current collecting disk is less than or equal to 3 times the thickness of the insulating tape.

[0009] In some embodiments, a segment has an overlapping area with another segment spaced apart by one segment on the surface of the first current collecting disk.

[0010] In some embodiments, the diameter of the electrode assembly is D mm, the unfolded length of the insulating tape ranges from D mm×3.14 to D mm×3.14+10 mm; the width of the insulating tape is 15 mm to 25 mm, and the secondary battery is a cylindrical battery.

[0011] In some embodiments, a non-through disconnect portion is provided between each two adjacent segments in the plurality of segments, and the depth of the disconnect portion is 3 mm to 14 mm along the radial direction of the secondary battery; in the direction from the center to the edge of the first current collecting disk, the edge of the disconnect portion does not exceed the edge of the first current collecting disk.

[0012] According to an embodiment of the present application, a battery pack is further provided, which may include any of the above-mentioned secondary batteries.

[0013] According to an embodiment of the present application, an electronic device is further provided, which may include the above-mentioned battery pack.

[0014] The beneficial technical effects of the utility model include:

[0015] The insulating tape is configured to have multiple sections, and the multiple sections are arranged in an overlapping manner on the surface of the first current collecting disc, so that the insulating tape and the first current collecting disc can fit tightly without protruding wrinkle gaps. When corrosion occurs inside the shell, corrosive substances (mainly metal corrosive substances) cannot enter the interior of the electrode assembly through the wrinkle gaps, avoiding metal corrosive substances causing short circuits between the positive and negative electrodes, thereby improving the problem of possible internal short circuits in the electrode assembly and improving the safety of the secondary battery; and reducing the assembly height of the electrode assembly, thereby increasing the energy density of the secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 A schematic diagram showing an electronic device according to an embodiment of the present application is a vehicle.

[0018] Figure 2A perspective view of a secondary battery according to an embodiment of the present application is shown.

[0019] Figure 3 A cross-sectional view of a secondary battery according to an embodiment of the present application is shown.

[0020] Figure 4 A partially enlarged schematic diagram of the pole side of a secondary battery according to an embodiment of the present application is shown.

[0021] Figure 5 A schematic plan view of a first current collecting disk and an insulating tape according to an embodiment of the present application is shown.

[0022] Figure 6 FIG. 1 is a schematic diagram showing an insulating tape not bonded to a first current collecting disk according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to better understand the spirit of the embodiments of the present application, some preferred embodiments of the present application are further described below.

[0024] The embodiments of the present application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are represented by similar reference numerals. The embodiments described herein with respect to the accompanying drawings are illustrative and diagrammatic and are intended to provide a basic understanding of the present application. The embodiments of the present application should not be construed as limiting the present application.

[0025] As used herein, the terms "substantially," "substantially," "essentially," and "about" are used to describe and account for small variations, such as variations within the margin of error for manufacturing processes. When used in conjunction with an event or circumstance, the terms may refer to instances where the event or circumstance occurred precisely as well as instances where the event or circumstance occurred very approximately.

[0026] In this specification, unless otherwise specified or limited, relative terms such as "central", "longitudinal", "lateral", "front", "rear", "right", "left", "inner", "outer", "lower", "higher", "horizontal", "vertical", "above", "below", "above", "below", "top", "bottom" and their derivatives (such as "horizontally", "downwardly", "upwardly", etc.) should be interpreted as referring to the directions described in the discussion or depicted in the drawings. These relative terms are only used for convenience of description and do not require that the present application be constructed or operated in a specific orientation.

[0027] For ease of description, “first,” “second,” “third,” etc. may be used herein to distinguish different components in a figure or a series of figures. “First,” “second,” “third,” etc. are not intended to describe the corresponding components.

[0028] The present application provides an electronic device 1000. For the convenience of description, the following embodiments are described by taking the electronic device 1000 as a vehicle as an example. Figure 1 The vehicle is equipped with a battery pack 1002 inside. Battery pack 1002 can be located at the bottom, front, or rear of the vehicle body 1001. Battery pack 1002 can be used to power the vehicle, for example, as the vehicle's operating power source. The working portion of the electronic device 1000 is electrically connected to battery pack 1002 to obtain electrical energy. The vehicle can be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, among others, but is not limited thereto. The working portion is the vehicle body, with battery pack 1002 located at the bottom of the vehicle body and providing electrical energy for the vehicle's operation and for the operation of its electrical components. However, in other embodiments, the electronic device 1000 can also be a mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, or electric tool, among others. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, among others. The working portion can draw electrical energy from battery pack 1002 and perform corresponding operations, such as the blade rotation unit of a fan or the dust collection unit of a vacuum cleaner. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys; electric tools include metal cutting tools, grinding tools, assembly tools, and railway tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. The present embodiment of the present application does not impose any particular limitation on the electronic device 1000.

[0029] Figure 2 1 shows a perspective view of a secondary battery 100 according to an embodiment of the present application, Figure 3 FIG2 shows a cross-sectional view of a secondary battery 100 according to an embodiment of the present application. In this embodiment, the secondary battery 100 may be a cylindrical battery.

[0030] In one example of the secondary battery of the present invention, Figures 2 to 3As shown, the secondary battery 100 includes a shell 200, which includes a peripheral side wall 109 and an end wall 111 connected to one end of the peripheral side wall 109. The other end of the peripheral side wall 109 opposite to the end wall 111 is provided with an opening 205. The cover plate 220 covers the opening 205 of the shell 200 to be used to encapsulate the electrode assembly 120 and the electrolyte together with the shell 200. The material of the shell 200 can be any of a variety of available materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The shell 200 can be cylindrical and define a accommodating cavity, and the electrode assembly 120 is arranged in the accommodating cavity. The diameter of the shell 200 can be determined according to the specific diameter size of the electrode assembly 120, such as 18 mm, 21 mm, 46 mm, etc. In some embodiments, the secondary battery 100 may be a 4680 cylindrical battery (46 mm in diameter, 80 mm in height), or the secondary battery 100 may be a 4695 cylindrical battery (46 mm in diameter, 95 mm in height), or the secondary battery 100 may be a 46120 cylindrical battery (46 mm in diameter, 120 mm in height).

[0031] The electrode assembly 120 is mainly formed by stacking and winding a first electrode sheet, a second electrode sheet, and a diaphragm located between the first electrode sheet and the second electrode sheet in sequence. The wound electrode assembly 120 has a winding center hole 120c. The electrode assembly 120 has a first electrode tab 121 and a second electrode tab 122 on opposite sides of its height direction H. The second electrode tab 122 faces the opening 205, and the first electrode tab 121 faces the end wall 111 of the shell 200 opposite to the opening 205. The direction from the second electrode tab 122 to the first electrode tab 121 is the height direction H of the electrode assembly 120. In some embodiments of the present application, the first electrode tab 121 is the positive electrode tab, and the second electrode tab 122 is the negative electrode tab. In some embodiments, the electrode assembly 120 may further include an insulating layer, such as an insulating tape, bonded to the outer ring of the first electrode sheet, the second electrode sheet, and the diaphragm after winding.

[0032] An inwardly protruding rolling groove 113 may be provided on the sidewall of the housing 200 adjacent to the opening 205. The electrode assembly 120 is disposed between the end wall 111 and the rolling groove 113, and the rolling groove 113 is capable of limiting movement of the electrode assembly 120 in the height direction H and the opposite direction between the end wall 111 and the rolling groove 113. The end of the peripheral sidewall 109 of the housing 200 on the side facing the opening 205 may be configured as a curling portion 32, which extends radially inwardly of the housing 200. The curling portion 32 is spaced apart from the rolling groove 113 along the height direction H, and the rolling groove 113 and the curling portion 32 can jointly clamp the cover plate 220.

[0033] The secondary battery 100 may further include a post 160 that passes through the end wall 111 and is insulated from the end wall 111. The post 160 may be electrically connected to the first tab 121 of the electrode assembly 120 via a first current collecting plate 301, thereby causing the post 160 to be charged, for example, positively charged. The second tab 122 may be electrically connected to the housing 200 via a second current collecting plate 302, thereby causing the housing 200 to be charged, for example, negatively charged.

[0034] In some embodiments, the positive electrode sheet (first electrode sheet) may include a positive electrode current collector and a positive electrode coating region, wherein the positive electrode coating region is coated on a portion of the surface of the positive electrode current collector. The positive electrode coating region is a positive electrode active material layer formed by coating the positive electrode active material. The portion of the positive electrode current collector not covered by the positive electrode coating region constitutes a positive electrode tab (first electrode tab 121). The negative electrode sheet (second electrode sheet) may include a negative electrode current collector and a negative electrode coating region, wherein the negative electrode coating region is coated on a portion of the surface of the negative electrode current collector. The negative electrode coating region is a negative electrode active material layer formed by coating the negative electrode active material. The portion of the negative electrode current collector not covered by the negative electrode coating region constitutes a negative electrode tab (second electrode tab 122).

[0035] Taking lithium-ion batteries as an example, the positive electrode current collector can be made of aluminum, and the positive electrode coating region can include a positive electrode active material, such as lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode current collector can be made of copper. The negative electrode coating region can include a negative electrode active material, such as carbon or silicon. The separator can be made of polypropylene (PP) or polyethylene (PE).

[0036] In an example of the secondary battery 100 of the present invention, the manufacturing method of the secondary battery 100 of the present invention includes the following steps:

[0037] Winding: The first electrode sheet, separator, and second electrode sheet are stacked and wound to form a wound structure. The uncoated portions of the positive electrode collector of the first electrode sheet and the negative electrode collector of the second electrode sheet constitute the first electrode tab 121 and the second electrode tab 122. The first electrode tab 121 and the second electrode tab 122 are bent along the radial direction of the electrode assembly 120.

[0038] The current collecting plates are welded to the electrode assembly: specifically, the first current collecting plates 301 and the second current collecting plates 302 are welded to the surface areas of the bent first electrode tab 121 and the second electrode tab 122 , respectively.

[0039] Inserting into the shell: The electrode assembly 120 welded to the first collecting plate 301 and the second collecting plate 302 is installed into the shell 200 through the opening 205. The method of installing the electrode assembly 120 in this step is not limited, for example, it can be installed manually or by a robot.

[0040] Install pole 160.

[0041] Injecting electrolyte: There is no limitation on the method of injecting the electrolyte. The electrolyte can be injected through the opening 205 or through an injection hole provided on the end wall 111. Preferably, in this embodiment, the electrolyte is injected through the opening 205, which reduces the process of providing an injection hole on the end wall 111 and allows the electrolyte to be directly injected through the existing opening 205, thereby simplifying the process and reducing costs.

[0042] Sealing: The cover plate 220 is sealed against the opening 205. Various sealing methods are available, and are not limited thereto. In some embodiments, the outer periphery of the housing 200 is first rolled to form a groove 113 recessed toward the center of the housing 200 to restrict movement of the electrode assembly 120 in the height direction H. A mechanical sealing process is then used to seal the cover plate 220 to form a curled edge 32, thereby sealing the cover plate 220 against the opening 205 of the housing 200. This step is a mature, low-cost, and highly efficient process.

[0043] Figure 4 FIG2 shows a partial enlarged schematic diagram of the pole side of a secondary battery according to an embodiment of the present application. Figure 3 and Figure 4 As shown, the secondary battery 100 may further include an insulating tape 150, which is positioned between the housing 200 and the first current collecting disc 301. The insulating tape 150 may be used to insulate the first current collecting disc 301 from the housing 200. The electrode assembly 120 has a side surface 120s, and the first current collecting disc 301 has a surface 301t facing away from the electrode assembly 120. The insulating tape 150 covers a portion of the side surface 120s of the electrode assembly 120 and a portion of the surface 301t of the first current collecting disc 301. In some embodiments, the insulating tape 150 may be an adhesive tape, and the surface of the insulating tape 150 facing the first current collecting disc 301 and the electrode assembly 120 is an adhesive surface.

[0044] However, in some prior art techniques, rectangular insulating tape is directly bonded to the sides of the electrode assembly and the first current collector. This creates wrinkles in the insulating tape covering the first current collector, allowing corrosive substances from the casing to diffuse through the gaps in the wrinkles and enter the electrode assembly, leading to short circuits within the battery cells and reducing the safety of the secondary battery. Furthermore, the wrinkles increase the height of the electrode assembly, interfering with assembly and adversely affecting the energy density of the secondary battery. In other prior art techniques, the insulating tape does not cover a sufficient area of ​​the first current collector, resulting in the exposed first current collector extending to the edge of the first current collector, making it easy for electrolyte to leak out.

[0045] Figure 5 A schematic plan view of a first current collecting disk and an insulating tape according to an embodiment of the present application is shown. Figure 5 The diagram is a plan view perpendicular to the height direction H. Figure 4 and Figure 5As shown, the insulating tape 150 may have a plurality of sections 152 along the edge 301 e of the surface 301 t of the first current collecting disk 301 .

[0046] The following references Figure 6 The formation process of the section 152 of the insulating tape 150 will be described. Figure 6 FIG. 1 is a schematic diagram showing an insulating tape 150 not bonded to the first current collecting plate 301 according to an embodiment of the present application. Figure 6 As shown, before the insulating tape 150 is bonded to the first current collecting tray 301, a plurality of disconnected portions 602 may be formed in the insulating tape 150. These disconnected portions 602 divide the insulating tape 150 into a plurality of separable segments 152, with one disconnected portion 602 positioned between each adjacent segment 152. Disconnected portions 602 do not penetrate the insulating tape 150, and are therefore non-through disconnected portions. Disconnected portions 602 may be formed, for example, by cutting or shearing the insulating tape 150. Portions of the insulating tape 150 not penetrated by disconnected portions 602 form connecting portions 154. Multiple segments 152 are connected to connecting portions 154. The number of disconnected portions 602 may be n, and the number of segments 152 may be n+1. In some embodiments, the insulating tape 150 may be cut or sheared n times to form n+1 segments 152.

[0047] In some embodiments, the spacing between adjacent disconnected portions 602 can be uniform. For example, the insulating tape 150 can be cut at equal intervals to form multiple segments 152 of the same length L2. In some embodiments, the length of the insulating tape 150 is L1, which can be in the range of 138 mm to 144 mm. For example, L1 can be 142 mm. In some embodiments, the number of disconnected portions 602 (n) ranges from 6 to 8, and the number of segments 152 can correspondingly range from 7 to 9. In this embodiment, the number of disconnected portions 602 is 7 (n=7), forming 8 segments 152.

[0048] In some embodiments, the depth D1 of each of the multiple breaks 602 extending into the insulating tape 150 may be the same. In some embodiments, the width W1 of the insulating tape 150 may range from 15 mm to 25 mm. In some embodiments, the depth D1 of each of the multiple breaks 602 extending into the insulating tape 150 may range from 3 mm to 14 mm. For example, in an embodiment where the width W1 of the insulating tape 150 is 20 mm, the depth D1 of each of the breaks 602 may range from 3 mm to 14 mm. In other embodiments, the width W1 of the insulating tape 150 may range from approximately 9 mm, and the depth D1 of each of the multiple breaks 602 extending into the insulating tape 150 may range from 3 mm to 6 mm.

[0049] In some embodiments, the thickness of insulating tape 150 can range from 10 μm to 100 μm. In some embodiments, the material of insulating tape 150 can be selected from one or more of the group consisting of polyimide, polyethylene, polypropylene, polytetrafluoroethylene, polyethylene terephthalate, and polybutylene terephthalate. The material of insulating tape 150 is not particularly limited, as long as it is an insulating material that does not dissolve, swell, or cause side reactions due to the electrolyte.

[0050] After the insulating tape 150 is formed into a plurality of segments 152, the Figures 4 and 5 As shown, the insulating tape 150 is bonded to the electrode assembly 120 and the first current collecting disc 301. After bonding, the insulating tape 150 covers a portion of the side surface 120s of the electrode assembly 120 and a portion of the surface 301t of the first current collecting disc 301. Since the plurality of segments 152 are formed by the disconnection portion 602 and are separable from each other, the plurality of segments 152 can be bonded to the surface 301t of the first current collecting disc 301 in a stacked manner. Figure 5 Two adjacent segments 152 may have an overlapping area on the surface 301t of the first current collecting plate 301. Taking adjacent segments 152a and 152b among the multiple segments 152 as an example, segment 152a and segment 152b have an overlapping area Ao1.

[0051] In the above technical solution, the insulating tape 150 is configured to have multiple sections 152, and the multiple sections 152 can be stacked on the surface 301t of the first current collecting disk 301, so that the insulating tape 150 and the first current collecting disk 301 can fit tightly together without any raised wrinkle gaps. When corrosion occurs inside the shell 200, the corrosive substances (mainly metal corrosive substances) cannot enter the interior of the electrode assembly 120 through the wrinkle gaps, which can prevent the metal corrosive substances from causing a short circuit between the positive and negative electrodes, thereby improving the problem of possible internal short circuit of the electrode assembly 120 and improving the safety of the secondary battery; and reducing the assembly height of the electrode assembly 120 and increasing the energy density of the secondary battery.

[0052] See also Figure 5 , at least a portion of each segment 152 covers a portion of the surface 301t of the first collecting plate 301. Figure 5 In the illustrated embodiment, the entirety of each segment 152 covers a portion of the surface 301 t of the first current collecting plate 301 . The connecting portion 154 of the insulating tape 150 is disposed on the side surface 120 s of the electrode assembly 120 .

[0053] In some embodiments, the area of ​​the surface 301t of the first current collecting tray 301 covered by the multiple segments 152 can account for 30% to 99% of the orthographic projection area of ​​the surface 301t of the first current collecting tray 301 along the direction of the first current collecting tray 301 toward the electrode assembly 120. In some embodiments, the area of ​​the surface 301t of the first current collecting tray 301 covered by the multiple segments 152 can account for 90% to 98% of the orthographic projection area of ​​the surface 301t of the first current collecting tray 301. Cutting the insulating tape 150 into multiple segments 152 allows the multiple segments 152 to be laminated and adhered to the surface 301t of the first current collecting tray 301. This allows the insulating tape 150 to cover a sufficiently large orthographic projection area of ​​the surface 301t of the first current collecting tray 301 to provide good insulation. In embodiments where the secondary battery 100 is a cylindrical battery, a rectangular insulating tape 150 is more likely to form wrinkles on the first current collecting tray 301. The technical solution of this application allows the insulating tape 150 to cover a sufficiently large orthographic projection area of ​​the surface 301t of the first current collecting plate 301, providing excellent insulation for the cylindrical battery. This also prevents wrinkles and corrosive substances from entering the electrode assembly 120 through the gaps between wrinkles, thereby alleviating the potential for internal short circuits in the electrode assembly 120 and improving the safety of the cylindrical battery. Furthermore, the assembly height of the electrode assembly 120 is reduced, increasing the energy density of the cylindrical battery.

[0054] In some embodiments, a segment 152 and another segment 152 separated by one segment 152 have an overlapping area on the surface of the first current collecting plate 301. Taking segment 152a among the multiple segments 152 as an example, segment 152a and another segment 152c are separated by a segment 152b, and segments 152a and 152c may have an overlapping area Ao2. In this embodiment, for rectangular segments 152a, overlapping segments 152a and 152c can avoid the formation of wrinkles between the larger segment 152a and the separated segment 152c. This prevents corrosive substances from entering the electrode assembly through the wrinkle gaps and causing internal short circuits, prevents wrinkles from affecting the assembly height of the electrode assembly 120, and improves the energy density of the cylindrical battery.

[0055] In some embodiments, the minimum thickness of the multiple segments 152 covering the surface 301t of the first current collecting tray 301 is less than or equal to three times the thickness of the insulating tape 150. That is, the minimum thickness of the multiple segments 152 on the surface 301t of the first current collecting tray 301 is less than the thickness of three layers of insulating tape 150. Compared to some existing solutions, if uncut insulating tape is adhered to the first current collecting tray, four or more layers of insulating tape may be stacked together, resulting in a thicker insulating tape on the first current collecting tray. According to the technical solution of the present application, since multiple segments 152 are provided on the first current collecting tray 301, the thickness of the insulating tape 150 (specifically, the multiple segments 152) on the first current collecting tray 301 can be controlled to not exceed three times the thickness of the insulating tape 150. This prevents the insulating tape 150 on the first current collecting tray 301 from warping excessively, which could easily intrude electrolyte and prevent corrosion caused by the electrolyte.

[0056] In the embodiment where the secondary battery is a cylindrical battery, the diameter of the electrode assembly 120 is D mm, and the unfolded length L1 of the insulating tape 150 (see FIG. Figure 6 ) can range from D mm × 3.14 to D mm × 3.14 + 10 mm. The length L1 of the insulating tape 150 exceeds the circumference of the side surface 120s of the electrode assembly 120 by no more than 10 mm. This range of length L1 can avoid affecting the cylindricity of the electrode assembly 120.

[0057] The surface 301t of the first current collecting disc 301 may have a boss 303 protruding from the surface 301t, and the boss 303 may be connected to the pole 160 of the secondary battery 100. In some embodiments, the area of ​​the boss 303 may account for 4%-6% of the area of ​​the surface 301t of the first current collecting disc 301. The plurality of sections 152 may expose the boss 303. In some embodiments, the area of ​​the boss 303 may account for 4%-7% of the orthographic projection area of ​​the surface 301t of the first current collecting disc 301. For example, in some embodiments, the area of ​​the surface 301t of the first current collecting disc 301 may be, for example, approximately 1256 mm 2 The area of ​​the boss 303 may be, for example, approximately 63.585 mm 2 The area covered by the plurality of segments 152 on the surface 301t of the first collecting plate 301 may be less than or equal to 1192.415 mm 2 .

[0058] The segment 152 may include two side edges 1521 and 1522 connected to the connecting portion 154 and facing each other, and a top edge 1523 connecting the two side edges, with the top edge 1523 being perpendicular to the two side edges 1521 and 1522. In other words, the segment 152 may have a rectangular shape. The rectangular segment 152 can be formed by simply cutting the insulating tape 150. This is a simple process and does not require removing any portion of the insulating tape 150. Therefore, the segment 152 can cover a sufficiently large area of ​​the surface 301t of the first current collecting tray 301.

[0059] The side edges 1521 and 1522 each have a first end e1 connected to the corresponding top edge 1523, and a second end e2 opposite the first end e1. The second end e2 is connected to the connecting portion 154. For two adjacent segments 152, taking adjacent segments 152a and 152b among the plurality of segments 152 as an example, the side edge 1521 of segment 152a and the corresponding side edge 1522 of adjacent segment 152b share a common second end e2. In this way, adjacent segments 152a and 152b are adjacent to each other (rather than spaced apart), so that the plurality of segments 152 can cover a sufficiently large area of ​​the surface 301t of the first current collecting plate 301.

[0060] refer to Figure 5 and Figure 6 As shown, the second end e2 shared by the side edges 1521, 1522 of the adjacent segments 152a, 152b is the edge of the disconnection portion 602 between the adjacent segments 152a, 152b (the cut root when the insulating tape 150 is cut). In some embodiments, in the direction from the center O of the first current collecting disc 301 to the edge 301e of the first current collecting disc 301, the edge of the disconnection portion 602 (i.e., the second end e2) does not exceed the edge 301e of the first current collecting disc 301. The edge of the disconnection portion 602 (i.e., the second end e2) can be located on the surface 301e of the first current collecting disc 301 or overlapped and aligned with the edge 301e. Figure 5 As an example, the edge of the disconnect portion 602 (i.e., the second end e2) overlaps and aligns with the edge 301e of the first current collecting disc 301. In some embodiments, after the insulating tape 150 is bonded to the first current collecting disc 301, the depth D1 of the disconnect portion 602 along the radial direction of the secondary battery 100 can be 3 mm to 14 mm. The depth dimension of the disconnect portion 602 can ensure that the edge of the disconnect portion 602 does not exceed the edge 301e of the first current collecting disc 301. The edge of the disconnect portion 602 does not exceed the edge 301e of the first current collecting disc 301, which can ensure that the side 120s of the electrode assembly 120 is covered by the insulating tape 150 without the disconnect portion 602, thereby ensuring a good insulation effect of the electrode assembly 120.

[0061] The embodiment of the present application also provides a battery pack 1002 (see Figure 1 ), including the secondary battery 100 of any one of the above items, and the battery pack 1002 can have the beneficial effects described above with respect to the secondary battery 100.

[0062] The embodiment of the present application also provides an electronic device 1000 (see Figure 1 ), including the above-mentioned battery pack 1002, and the electronic device 1000 can have the beneficial effects described above with respect to the secondary battery 100 and / or the battery pack 1002.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A secondary battery, characterized in that: include: The housing comprises a peripheral side wall and an end wall connected to one end of the peripheral side wall, wherein the other end of the peripheral side wall is provided with an opening; An electrode assembly, comprising a first electrode piece, a second electrode piece, and a diaphragm disposed between the first electrode piece and the second electrode piece, the electrode assembly having a first electrode tab and a second electrode tab; a pole passing through the end wall and insulated from the end wall; a first current collecting plate, electrically connected to the first electrode tab and the electrode column; a cover plate, covering the opening and encapsulating the electrode assembly together with the shell; as well as an insulating tape located between the housing and the first current collecting plate, covering a portion of a side surface of the electrode assembly and a portion of a surface of the first current collecting plate facing away from the electrode assembly; The insulating tape has a plurality of sections along the edge of the surface of the first current collecting disk, and two adjacent sections have an overlapping area on the surface of the first current collecting disk.

2. The secondary battery according to claim 1, wherein At least a portion of each of the segments covers a portion of the surface of the first collecting plate.

3. The secondary battery according to claim 1, wherein An area of ​​the surface of the first current collecting disk covered by the multiple segments accounts for 30% to 99% of an orthographic projection area of ​​the surface of the first current collecting disk along a direction of the first current collecting disk toward the electrode assembly.

4. The secondary battery according to claim 1, wherein An area of ​​the surface of the first current collecting disk covered by the plurality of segments accounts for 90% to 98% of an orthographic projection area of ​​the surface of the first current collecting disk along a direction of the first current collecting disk toward the electrode assembly.

5. The secondary battery according to claim 1, wherein A minimum thickness of the plurality of sections covering the surface of the first current collecting disk is less than or equal to three times the thickness of the insulating tape.

6. The secondary battery according to claim 1, wherein The segment and another segment spaced apart by one segment have an overlapping area on the surface of the first current collecting disk.

7. The secondary battery according to claim 1, wherein The diameter of the electrode assembly is D mm, and the expanded length of the insulating tape ranges from D mm × 3.14 to D mm × 3.14 + 10 mm; The width of the insulating tape is 15 mm to 25 mm. The secondary battery is a cylindrical battery.

8. The secondary battery according to claim 1, wherein A non-through disconnection portion is provided between each two adjacent sections of the plurality of sections. Along the radial direction of the secondary battery, the depth of the disconnection portion is 3 mm to 14 mm. In a direction from the center to the edge of the first current collecting disk, the edge of the disconnection portion does not exceed the edge of the first current collecting disk.

9. A battery pack, characterized in that: The secondary battery comprises the secondary battery according to any one of claims 1 to 8.

10. An electronic device, characterized in that: Comprising the battery pack as claimed in claim 9.

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