Secondary battery

Abstract

The present application provides a secondary battery comprising: a case comprising a peripheral side wall and an end wall connected to one end thereof; the top cover assembly covers the opening in the other end of the peripheral side wall, the top cover assembly and the shell jointly define a containing cavity, and the top cover assembly comprises a top cover body and an electrode terminal; the electrode assembly is located in the containing cavity and comprises a first pole piece, a second pole piece and a diaphragm arranged between the first pole piece and the second pole piece, a pole lug is arranged at the end, facing the top cover assembly, of the electrode assembly, and the peripheral face of the electrode assembly comprises two straight sections oppositely arranged in the first direction and a corner section connecting the two straight sections; the first insulating tape is at least adhered to the two straight sections, the tab comprises a first side and a second side which are opposite to each other along a second direction, the insulating tapes adhered to the two straight sections extend out of the first side and the second side along the second direction, and the second insulating tape is positioned on the peripheral surface of the electrode assembly and fixes the ending end of the diaphragm on the peripheral surface. According to the technical scheme, the production cost can be reduced at least.

Description

TECHNICAL FIELD

[0001] The utility model relates to the battery technical field more particularly, relate to a kind of secondary batteries. BACKGROUND

[0002] In the field of new energy power battery, secondary battery refers to rechargeable battery, also called renewable battery or storage battery. Unlike primary battery, secondary battery can be charged and discharged multiple times through reverse charging for repeated use. Square can battery is one of secondary batteries. The existing square can battery is pasted with end adhesive on the surface of its electrode assembly, and is provided with cell insulating film (mylar) and bottom support plate, so that the electrode assembly and the shell are separated, to avoid the safety problem caused by the contact between the two. The existing secondary battery still needs to be further improved in terms of production cost. SUMMARY

[0003] In view of the problems in the related art, the utility model aims to provide a secondary battery, which can at least reduce production cost.

[0004] To achieve the above-mentioned purpose, the utility model provides a secondary battery, which comprises: a shell 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; a top cover assembly covering the opening of the shell and defining a containing cavity together with the shell, the top cover assembly comprising a top cover body and an electrode terminal provided on the top cover body, wherein the direction of the end wall towards the top cover assembly is the height direction of the secondary battery; an electrode assembly located in the containing cavity, comprising a first electrode sheet, a second electrode sheet and a separator provided between the first electrode sheet and the second electrode sheet, the electrode assembly being provided at one end facing the top cover assembly with a tab connected to the corresponding electrode terminal, the outer peripheral surface of the electrode assembly comprising two flat sections oppositely arranged along a first direction, and two corner sections connecting the two flat sections and respectively located at opposite sides of the electrode assembly along a second direction, the first direction, the second direction and the height direction being perpendicular to each other; a first insulating tape adhered to at least two flat sections, wherein the tab comprises a first side and a second side opposite along the second direction, the insulating tape adhered to the two flat sections extending beyond the first side and the second side along the second direction; and a second insulating tape located on the outer peripheral surface of the electrode assembly and fixing the end of the separator at the outer peripheral surface.

[0005] In some embodiments, the adhesive force of the first insulating tape is greater than that of the second insulating tape.

[0006] In some embodiments, the first insulating tape is spaced apart from the second insulating tape along the height direction.

[0007] In some embodiments, the first insulating tape surrounds the electrode assembly at least one round along the circumference of the outer circumferential surface of the electrode assembly, and the length of the end of the roll of the first insulating tape beyond the beginning of the roll is in the range of 1mm to 3mm.

[0008] In some embodiments, the second insulating tape is located on a flat section, and the length of the second insulating tape along the second direction is less than 1 / 2 of the length of the flat section.

[0009] In some embodiments, the upper end of the first insulating tape beyond the upper end of the outer circumferential surface along the height direction.

[0010] In some embodiments, the height of the upper end of the first insulating tape beyond the upper end of the outer circumferential surface along the height direction is in the range of 1mm to 3mm.

[0011] In some embodiments, the first insulating tape comprises a substrate layer and a glue layer, and the glue layer is located between the electrode assembly and the substrate layer, wherein the upper end of the glue layer is not lower than the upper end of the outer circumferential surface along the height direction, and the upper end of the substrate layer is beyond the upper end of the glue layer.

[0012] In some embodiments, the part of the first insulating tape beyond the upper end of the outer circumferential surface extends along the height direction.

[0013] In some embodiments, the thickness of the first insulating tape is in the range of 25μm to 70μm.

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

[0015] The above technical solution of the application uses the second insulating tape to fix the end, and the first insulating tape plays the role of insulating the part of the flat section of the electrode assembly and the shell. Therefore, the existing cell insulating film can be saved, and the production cost of the secondary battery is saved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 is a three-dimensional schematic view of a part of the electrode assembly in the existing square shell battery.

[0018] Figure 2 shows a three-dimensional schematic view of a secondary battery according to an embodiment of the application.

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

[0020] Figure 4A A perspective view of an electrode assembly in a secondary battery according to an embodiment of the present application is shown.

[0021] Figure 4B A front view of an electrode assembly in a secondary battery according to an embodiment of the present application is shown.

[0022] Figure 5 A plan view of a portion of a first insulating tape according to an embodiment of the present application is shown.

[0023] Figure 6A A perspective view of an electrode assembly in a secondary battery according to another embodiment of the present application is shown.

[0024] Figure 6B A front view of an electrode assembly in a secondary battery according to another embodiment of the present application is shown.

[0025] Figure 7 A schematic view of an embodiment of an electronic device as a vehicle according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] For better understanding of the spirit of the embodiments of the present application, the following further describes the same in connection with some preferred embodiments of the present application.

[0027] Embodiments of the present application will be described in detail below. Throughout the present specification, the same or similar components and components having the same or similar functions are denoted by the same reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative in nature, diagrammatic in nature, and serve to provide a basic understanding of the present application. The embodiments of the present application should not be construed as limiting the present application.

[0028] As used herein, the terms "substantially", "generally", "essentially", and "about" are used to describe and account for small variations, e.g. within the range of error of a manufacturing process. When used in connection with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs exactly, as well as instances in which the event or circumstance occurs approximately.

[0029] 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 (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0030] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0031] Figure 1 This is a three-dimensional schematic diagram of a portion of the electrode assembly in an existing prismatic battery. See also: Figure 1 As shown, in existing prismatic batteries, the surface of the electrode assembly 10 is first covered with finishing adhesive 14, and then a cell insulating film (mylar) and a base plate are installed. This separates the electrode assembly 10 from the battery casing, preventing safety issues caused by contact between the two. The assembly sequence of existing prismatic batteries is as follows: the adapter piece is first welded to the tabs of the electrode assembly, then the adapter piece is welded to the electrode terminals. After welding, the cell insulating film is wrapped around the electrode assembly, and then the electrode assembly wrapped with the cell insulating film is installed into the casing. Existing prismatic batteries still require further improvement in terms of production costs.

[0032] Figure 2 A perspective view of a secondary battery 100 according to an embodiment of this application is shown. Figure 3 A cross-sectional schematic diagram of a secondary battery 100 according to an embodiment of this application is shown. Figure 4A A perspective view of the electrode assembly in a secondary battery 100 according to an embodiment of this application is shown. Figure 4B This is a front view schematic diagram of the electrode assembly in a secondary battery 100 according to an embodiment of this application. In the illustrated embodiment, the secondary battery 100 is a prismatic battery.

[0033] Combination Figure 2 to Figure 3As shown, the secondary battery 100 includes a case 200 including a peripheral side wall 109 and an end wall 111 connected to one end of the peripheral side wall 109, and an opening 205 is provided at the other end of the peripheral side wall 109 opposite the end wall 111. A top cover assembly 220 is fitted to the opening 205 of the case 200 for defining a receiving cavity together with the case 200, and the electrode assembly 120 is located in the receiving cavity. The end wall 111 is in the height direction Z of the secondary battery in the direction of the top cover assembly 220. In the present embodiment, two electrode assemblies 120 are stacked in the case in the thickness direction of the electrode assembly 120. In some embodiments, one or more than two electrode assemblies 120 can be provided in the case 200.

[0034] The top cover assembly 220 includes a top cover body 221 and a first electrode terminal 223 and a second electrode terminal 224 provided on the top cover body 221. The first electrode terminal 223 and the second electrode terminal 224 can pass through the top cover body 221 and be insulated from the top cover body 221. One of the first electrode terminal 223 and the second electrode terminal 224 is a positive electrode terminal, and the other is a negative electrode terminal. The electrode assembly 120 is provided with a first tab 121 and a second tab 122 at one end thereof toward the top cover assembly 220. One of the first tab 121 and the second tab 122 is a positive electrode tab, and the other is a negative electrode tab. The first tab 121 and the second tab 122 of the electrode assembly 120 are connected to the corresponding first electrode terminal 223 and second electrode terminal 224, respectively. In some embodiments, the first tab 121 and the first electrode terminal 223, and the second tab 122 and the second electrode terminal 223 can be connected by corresponding adapter pieces 226.

[0035] In some embodiments, the electrode assembly 120 is a stacked body formed by stacking a first electrode sheet, a second electrode sheet, and a separator between the first electrode sheet and the second electrode sheet in sequence, or is a wound body formed by winding the first electrode sheet, the second electrode sheet, and the separator. The electrode assembly 120 can be flat. Correspondingly, the case 200 can have a flat shape and have a cuboid shape. In the present specification, the electrode assembly 120 is described as a wound body, and the first tab 121 and the second tab 122 are located at the same end of the electrode assembly 120.

[0036] In some embodiments, the positive electrode tab (e.g., the first electrode tab) can include a positive current collector and a positive coating region coated on a partial surface of the positive current collector. The positive coating region is a positive active material layer formed by coating of a positive active material. The portion of the positive current collector not covered by the positive coating region constitutes a positive tab (e.g., the first tab 121). The negative electrode tab (e.g., the second electrode tab) can include a negative current collector and a negative coating region coated on a partial surface of the negative current collector. The negative coating region is a negative active material layer formed by coating of a negative active material. The portion of the negative current collector not covered by the negative coating region constitutes a negative tab (e.g., the second tab 122).

[0037] Taking a lithium ion battery as an example, the material of the positive current collector can be aluminum, the positive coating region can include a positive active material, and the positive active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The material of the negative current collector can be copper. The negative coating region can include a negative active material, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0038] Generally, in order to ensure the insulation effect of the first electrode tab and the second electrode tab, the winding start end and the winding end of the separator both exceed the winding start end and the winding end of the first electrode tab and the second electrode tab along the winding direction of the electrode assembly 120. And the winding end of the separator is used as the winding end of the electrode assembly 120.

[0039] In combination Figure 3 to Figure 4B As shown, the electrode assembly 120 has an outer circumferential surface 120s, which includes two flat segments 120a oppositely arranged along a direction X (which can be referred to as a first direction), and two corner segments 120b connecting the two flat segments 120a, and the two corner segments 120b are respectively located at opposite sides of the electrode assembly 120 along a direction Y (which can be referred to as a second direction Y). The flat segment 120a can also be referred to as a large surface of the electrode assembly 120, and in Figure 4A only one flat segment 120a can be seen in the figure.

[0040] The secondary battery 100 further includes a first insulating tape 150 adhered to at least the two flat segments 120a of the outer circumferential surface 120s of the electrode assembly 120. The first insulating tape 150 can be directly adhered to the electrode assembly 120, and the winding end of the electrode assembly 120 is usually located on the flat segment 120a, so the first insulating tape 150 can play a role of fixing the winding end of the electrode assembly 120, and thus the end tape can be replaced by the first insulating tape 150.

[0041] In addition, the first and second tabs 121 and 122 include a first side 128 and a second side 129 opposite in the direction Y, which are the outermost sides of both the first and second tabs 121 and 122 in the direction Y. In the direction Y, one end of the first insulating tape 150 adhered to the flat section 120a is closer to the corresponding one corner section 120b than the first side 128, and the other end of the first insulating tape 150 adhered to the flat section 120a is closer to the corresponding other corner section 120b than the second side 129. In this way, the first insulating tape 150 adhered to the two flat sections 120a extends beyond the first and second sides 128 and 129 in the direction Y. In the present embodiment, one side 158 of the first insulating tape 150 in the direction Y extends beyond the first side 128 of the first tab 121 and is closer to the corresponding corner section 120b, and the other side 159 of the first insulating tape 150 in the direction Y extends beyond the second side 129 of the second tab 122 and is closer to the corresponding other corner section 120b.

[0042] In some embodiments, the secondary battery 100 can further include a second insulating tape 170 located on the outer circumferential surface 120s of the electrode assembly 120, and the second insulating tape 170 can fix the end of the separator of the electrode assembly 120 at the outer circumferential surface 120s. The second insulating tape 170 can fix the end of the separator by adhering to the end.

[0043] The above technical solutions of the present application use the second insulating tape 170 to fix the end, and use the first insulating tape 150 to insulate the part of the flat section 120a of the electrode assembly 120 from the case. Therefore, the existing cell insulating film can be omitted, and the production cost of the secondary battery is saved.

[0044] In some embodiments, the adhesive force of the first insulating tape 150 can be greater than the adhesive force of the second insulating tape 170. The adhesive force of the second insulating tape 170 cannot be too large, and too large adhesive force will restrict the expansion of the electrode assembly, and the adhesive force of the first insulating tape 150 is greater, which is convenient for continuously providing the function of separating the tabs from the case.

[0045] In some embodiments, the first insulating tape 150 is spaced apart from the second insulating tape 170 in the direction opposite to the height direction Z. In other embodiments, the first insulating tape 150 can also cover at least part of the second insulating tape 170,

[0046] In the height direction Z, the upper end 150t of the first insulating tape 150 can exceed the upper end 120t of the outer circumferential surface 120s to separate at least a portion of the first and second tabs 121 and 122 from the shell 200. The first insulating tape 150 can be directly positioned between the electrode assembly 120 and the shell 200. Since the first and second tabs 121 and 122 are closest to the shell 200 at a position adjacent to the upper end 120t of the outer circumferential surface 120s, the upper end 150t of the first insulating tape 150 exceeding the upper end 120t of the outer circumferential surface 120s can function to insulate the tabs from the shell. In the opposite direction of the height direction Z, the lower end 150b of the first insulating tape 150 is positioned on the outer circumferential surface 120s of the electrode assembly 120. Since the lower end of the electrode assembly 120 is not provided with a tab, the first insulating tape 150 only needs to exceed the outer circumferential surface 120s at the end where the tab is provided, and the non-tab area can not be provided. In some embodiments, the first insulating tape 150 can be directly adhered to the electrode assembly 120 after the tabs are welded to the electrode terminals.

[0047] In some embodiments, in the height direction Z, the upper end 150t of the first insulating tape 150 exceeds the upper end 120t of the outer circumferential surface 120s by a height H1 in the range of 1 mm to 3 mm. The upper end 150t of the first insulating tape 150 exceeding a height of 1 mm to 3 mm can also have a better effect of blocking the laser when the shell 200 is welded to the top cover assembly 220, thereby avoiding damage to the electrode assembly 120 by the laser.

[0048] The portion of the first insulating tape 150 that exceeds the upper end 120t of the outer circumferential surface 120s extends in the height direction Z, that is, the portion of the first insulating tape 150 that exceeds the upper end 120t is upright. In some embodiments, the thickness of the first insulating tape 150 can be in the range of 25 μm to 70 μm. Preferably, the thickness of the first insulating tape 150 can be in the range of 50 μm to 70 μm. Within this suitable thickness range, the first insulating tape 150 can have a better upright effect, and a thickness that is too small can easily wrinkle when it is upright, resulting in a poor insulating effect.

[0049] Figure 5 is a plan view of a portion of the first insulating tape 150 according to an embodiment of the present application. Referring to Figure 5 As shown, the first insulating tape 150 can include a substrate layer 152 and a glue layer 154, and the glue layer 154 is positioned between the electrode assembly 120 and the substrate layer 152. The glue layer 154 is used to directly adhere to the outer circumferential surface 120s of the electrode assembly 120.

[0050] In some embodiments, the substrate layer 152 is a PI (polyimide) substrate because PI has better heat resistance. In some embodiments, the substrate layer 152 can also be a PET (polyethylene terephthalate) substrate. Generally, the cell insulation film in existing prismatic batteries is PP, and the thickness of the cell insulation film is 150 μιη. The substrate layer 152 of the first insulation tape 150 uses a PET substrate, and the hardness of PET is higher than that of PP, so under the same conditions, a PET of 60 μιη can achieve the hardness requirement of 150 μιη of PP. Therefore, using the PET substrate of the cell insulation film to replace the PP substrate of the existing cell insulation film can improve the energy density of the secondary battery.

[0051] The area of the substrate layer 152 of the first insulation tape 150 is greater than the area of the adhesive layer 154. Along the height direction Z, the adhesive layer 154 has an upper end 154t, and the substrate layer 152 has an upper end, i.e., the upper end 150t of the first insulation tape 150. In the opposite direction of the height direction Z, the substrate layer 152 and the adhesive layer 154 can have aligned lower ends, i.e., the lower end 150b of the first insulation tape 150. The upper end 150t of the substrate layer 152 exceeds the upper end 154t of the adhesive layer 154. The upper end 154t of the adhesive layer 154 is not lower than the upper end 120t of the outer surface 120s along the height direction Z. The lower end 150b of the adhesive layer 154 is located on the outer surface 120s of the electrode assembly 120. In this way, the area of the adhesive layer 154 can be controlled on the electrode assembly 120.

[0052] The area between the upper end 154t of the adhesive layer 154 and the upper end 150t of the substrate layer 152 is the substrate layer 152 without the adhesive layer. Along the height direction Z, the distance between the upper end 154t of the adhesive layer 154 and the upper end 150t of the substrate layer 152 can be 1 mm-3 mm. In some embodiments, the substrate layer 152 between the upper end 154t of the adhesive layer 154 and the upper end 150t of the substrate layer 152 is the area of the first insulation tape 150 exceeding the upper end 120t of the outer surface 120s.

[0053] Figure 6A A perspective view of an electrode assembly in a secondary battery according to another embodiment of the application is shown. Figure 6B A front view of an electrode assembly in a secondary battery according to another embodiment of the application is shown. Figure 6A And Figure 6B Aspects of the embodiments shown can be similar to those described above with reference to Figure 2 to Figure 5 The following only describes Figure 6A And Figure 6B The differences between the embodiments shown.

[0054] Reference Figure 6A And Figure 6BAs shown, in the present embodiment, the first insulating adhesive tape 150 wraps around the electrode assembly 120 at least one turn. The length of the end of the first insulating adhesive tape 150 beyond the beginning of the first insulating adhesive tape 150 along the circumference of the outer surface 120s of the electrode assembly 120 is 1mm to 3mm. That is, after the first insulating adhesive tape 150 is wound around the electrode assembly 120 for one turn, the first insulating adhesive tape 150 is wound for an additional 1mm to 3mm, so that the first insulating adhesive tape 150 has an overlapping region at the beginning and the end, and the length of the overlapping region is 1mm to 3mm. This can further facilitate the continuous provision of the function of separating the tab and the housing.

[0055] The second insulating adhesive tape 170 is only partially arranged on one large surface of the electrode assembly 120, and the length of the second insulating adhesive tape 170 along the length direction Y of the electrode assembly 120 can be 1 / 4 to 1 / 2 of the length of the corresponding electrode assembly 120. Since the second insulating adhesive tape 170 is used for the purpose of ending, it can have a shorter length.

[0056] In the above description, the electrode assembly 120 is taken as a winding body, and the first tab 121 and the second tab 122 are located at the same end of the electrode assembly 120. It should be understood that in other embodiments, the electrode assembly 120 can also be a laminated body. Moreover, in the embodiment in which the electrode assembly 120 is a laminated body, the electrode assembly 120 also includes two flat sections (i.e., large surfaces) arranged opposite to each other along the direction X, and in the laminated body, the two parts connecting the two flat sections on the opposite sides of the laminated body along the direction Y are two corner sections. The embodiments of the present application can be applied to both winding body and laminated body forms of electrode assemblies.

[0057] In addition, in other embodiments, the first tab 121 and the second tab 122 can be located at opposite ends of the electrode assembly 120 along the direction Z. Moreover, in the embodiment in which the first tab 121 and the second tab 122 are located at opposite ends of the electrode assembly 120, the first insulating adhesive tape 150 can have a similar arrangement at the opposite ends of the electrode assembly 120 as described above.

[0058] Figure 7 The electronic device according to the embodiments of the present application is an example of the embodiment of a vehicle. Referring to Figure 7 As shown, the embodiments of the present application also provide a battery pack 1002 including the secondary battery 100 of any one of the above embodiments, and the battery pack 1002 can have the beneficial effects described above with respect to the secondary battery 100.

[0059] The embodiments of the present application also provide an electronic device 1000, which can include the battery pack 1002 described above. The following embodiments are described by taking the electronic device 1000 as a vehicle for convenience of description. Referring to Figure 7The vehicle is provided with a battery pack 1002 in the interior, which can be arranged at the bottom, head or tail of the vehicle body 1001. The battery pack 1002 can be used for power supply of the vehicle, for example, the battery pack 1002 can be used as the operating power supply of the vehicle. The working part of the electronic device 1000 is electrically connected with the battery pack 1002 to obtain electric energy support. The vehicle can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid automobile or a range extended automobile, but is not limited thereto. The working part is the vehicle body, the battery pack 1002 is arranged at the bottom of the vehicle body, and provides electric energy support for driving of the vehicle or operation of electrical elements in the vehicle. However, in some other embodiments, the electronic device 1000 can also be a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The working part can obtain electric energy of the battery pack 1002, and make corresponding working unit parts, for example, a fan blade rotating unit, a dust collection working unit of a dust collector, etc. The electric toy includes a fixed or mobile electric toy, for example, a game machine, an electric automobile toy, an electric ship toy and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator and an electric planer, etc. The embodiments of the present application do not specially limit the above-mentioned electronic device 1000.

[0060] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A secondary battery characterized by comprising: The secondary battery comprises: a case including 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; a top cover assembly covering the opening of the case and defining a receiving cavity together with the case, the top cover assembly including a top cover body and electrode terminals provided on the top cover body, wherein the end wall is in a height direction of the secondary battery in a direction of the top cover assembly; an electrode assembly located in the receiving cavity and including a first electrode tab, a second electrode tab, and a separator provided between the first electrode tab and the second electrode tab, the electrode assembly being provided at one end facing the top cover assembly with tabs connected to corresponding electrode terminals, an outer peripheral surface of the electrode assembly including two flat sections oppositely arranged along a first direction, and two corner sections connecting the two flat sections and respectively located at opposite sides of the electrode assembly along a second direction, the first direction, the second direction, and the height direction being perpendicular to each other; a first insulating tape adhered to at least the two flat sections, wherein the tabs include a first side and a second side opposite along the second direction, the insulating tape adhered to the two flat sections extending beyond the first side and the second side along the second direction, a second insulating tape located on the outer peripheral surface of the electrode assembly and fixing a tail end of the separator at the outer peripheral surface.

2. The secondary battery according to claim 1, wherein an adhesive strength of the first insulating tape is greater than an adhesive strength of the second insulating tape.

3. The secondary battery according to claim 1, wherein the first insulating tape is spaced apart from the second insulating tape along the height direction.

4. The secondary battery according to claim 1, wherein the first insulating tape surrounds the electrode assembly at least one turn along a circumferential direction of the outer peripheral surface of the electrode assembly, and a length range of a winding end of the first insulating tape beyond a winding start end is 1 mm to 3 mm.

5. The secondary battery according to claim 4, wherein the second insulating tape is located on one of the flat sections, and a length of the second insulating tape along the second direction is less than 1 / 2 of a length of the flat section.

6. The secondary battery according to claim 1, wherein an upper end of the first insulating tape is beyond an upper end of the outer peripheral surface along the height direction.

7. The secondary battery according to claim 6, wherein a height range of the upper end of the first insulating tape beyond the upper end of the outer peripheral surface along the height direction is 1 mm to 3 mm.

8. The secondary battery according to claim 6, wherein the first insulating tape includes a base material layer and a glue layer, the glue layer being located between the electrode assembly and the base material layer, wherein an upper end of the glue layer is not lower than the upper end of the outer peripheral surface along the height direction, and an upper end of the base material layer is beyond the upper end of the glue layer.

9. The secondary battery according to claim 6, wherein A portion of the first insulating tape that exceeds the upper end of the outer peripheral surface extends in the height direction.

10. The secondary battery according to claim 9, wherein The thickness of the first insulating tape is in a range of 25 μm to 70 μm.

Images