Secondary battery, battery pack, and electronic device

Abstract

The embodiment of the utility model discloses a secondary battery, a battery pack and an electronic device, the secondary battery comprises a shell, the shell comprises 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 is provided with an opening, and a rolling groove protruding inwards is formed in the position, close to the opening, of the peripheral side wall; the electrode assembly is accommodated in the shell and is positioned between the end wall and the rolling groove; wherein the height direction of the secondary battery is a first direction, the rolling groove comprises two straight parts and a bent part, the two straight parts extend towards the interior of the shell along a second direction perpendicular to the first direction, the bent part is connected to the two straight parts, the two straight parts are oppositely arranged in the first direction, and the minimum distance H1 between the two straight parts in the first direction meets the condition that 0.2 mm < = H1 < = 1 mm. According to the technical scheme, the sealing performance and the safety performance of the battery can be improved at least.

Description

Technical Field

[0001] This utility model relates to the field of energy storage equipment technology, and more specifically, to a secondary battery, battery pack and electronic device. Background Technology

[0002] In the field of new energy power batteries, the application of rechargeable batteries is becoming increasingly widespread. These batteries (such as lithium-ion batteries) can be used in vehicles, energy storage, mobile phones, tablets, wearable devices, power banks, e-cigarettes, digital products, power tools, power units, and other electronic devices. One type of rechargeable battery is the cylindrical battery, which includes a casing and an electrode assembly. The electrode assembly consists of a positive electrode, a first separator, a negative electrode, and a second separator, which are stacked sequentially and wound to form the electrode assembly, which is then encapsulated within the casing. However, existing rechargeable batteries still require further improvement in areas such as sealing and safety. Utility Model Content

[0003] In view of the problems existing in the related technologies, the purpose of this utility model is to provide a secondary battery, battery pack and electronic device, so as to at least improve the battery sealing and safety performance.

[0004] To achieve the above objectives, embodiments of this application provide a secondary battery, comprising: a housing, the housing including a peripheral sidewall and an end wall connected to one end of the peripheral sidewall, the other end of the peripheral sidewall having an opening, and an inwardly protruding groove provided near the opening of the peripheral sidewall; an electrode assembly, housed in the housing and located between the end wall and the groove; wherein, the height direction of the secondary battery is a first direction, the groove includes two straight portions extending toward the interior of the housing along a second direction perpendicular to the first direction, and a bent portion connecting the two straight portions, the two straight portions being arranged opposite to each other in the first direction, and the minimum distance H1 between the two straight portions in the first direction satisfying 0.2mm≤H1≤1mm.

[0005] In some embodiments, the outer surface of the peripheral sidewall defines a groove by a groove, wherein the depth L1 of the groove satisfies 3mm≤L1≤4mm, and the depth L1 is the distance from the outer surface of the peripheral sidewall to the inner edge of the bend of the groove along the second direction.

[0006] In some embodiments, the minimum thickness A of the portion of the peripheral sidewall that forms the groove is greater than 0.3 mm, and the ratio of minimum thickness A to maximum thickness of the peripheral sidewall is ≥70%.

[0007] In some embodiments, the ratio of minimum spacing H1 to depth L1 satisfies 5% ≤ H1 / L1 ≤ 33%.

[0008] In some embodiments, the ratio of minimum thickness A to minimum spacing H1 satisfies 30% ≤ A / H1 ≤ 2.

[0009] In some embodiments, the first straight portion of the two straight portions is close to the other end of the peripheral sidewall, and the other end of the peripheral sidewall forms a rolled edge portion extending inward toward the interior of the housing in a second direction on the side of the groove facing away from the electrode assembly. The first surface of the first straight portion faces away from the rolled edge portion, the first surface of the rolled edge portion faces away from the groove, and the maximum distance H2 between the first surface of the first straight portion and the first surface of the rolled edge portion in a first direction satisfies 2mm≤H2≤3mm.

[0010] In some embodiments, the secondary battery further includes: a first current collector located on the side of the electrode assembly facing the opening, the first current collector including a first portion electrically connected to the electrode assembly and a second portion connecting the groove, wherein, along a second direction from the peripheral sidewall into the interior of the housing, the end of the second portion away from the first portion does not extend beyond one end of the groove.

[0011] In some embodiments, one end of the second portion is located above the bend of the groove along a first direction.

[0012] Embodiments of this application also provide a battery pack, which includes any of the battery packs described above.

[0013] Embodiments of this application also provide an electronic device comprising any of the aforementioned secondary batteries.

[0014] The beneficial technical effects of this utility model are as follows:

[0015] The embodiments of this application set the minimum distance H1 between the two straight parts of the rolling groove on the secondary battery casing to a range of 0.2mm≤H1≤1mm, which can effectively avoid the problem of easy peeling of the nickel layer inside and outside the casing, reduce the internal risk of the cell, and improve the rust resistance of the casing. It can also make the casing have sufficient strength during sealing, thereby improving the sealing and safety performance of the battery. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

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

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

[0020] Figure 4 yes Figure 3 A magnified view of a portion of region A1 in the diagram.

[0021] Figure 5 yes Figure 3 and Figure 4 A magnified view of a portion of the groove. Detailed Implementation

[0022] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0023] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0024] As used herein, the terms “approximately,” “substantially,” “substantially,” and “about” are used to describe and indicate minor variations. When used in conjunction with an event or situation, the terms may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately.

[0025] 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.

[0026] 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.

[0027] This application provides an electronic device 1000. For ease of explanation, the following embodiments use a vehicle as an example to illustrate the electronic device 1000. See also... Figure 1The vehicle has a battery pack 1002 installed inside, which can be located at the bottom, front, or rear of the vehicle body 1001. The battery pack 1002 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part is the vehicle body, and the battery pack 1002 is located at the bottom of the vehicle body, providing electrical power for the vehicle's movement or the operation of its internal electrical components. However, in some other embodiments, the electronic device 1000 can also be a mobile phone, portable device, laptop, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part can obtain electrical energy from the battery pack 1002 and perform corresponding functions, such as a fan blade rotation unit or a vacuum cleaner's suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electronic device 1000.

[0028] Battery pack 1002 may include multiple secondary batteries (such as cylindrical batteries). In the following description, cylindrical batteries are used as an example of secondary batteries. Figure 2 A perspective view of a secondary battery 100 according to an embodiment of this application is shown. Figure 3 A cross-sectional view of a secondary battery 100 according to an embodiment of this application is shown.

[0029] Combination Figures 2 to 3As shown, the secondary battery 100 includes a housing 200, which includes a peripheral sidewall 109 and an end wall 111 connected to one end of the peripheral sidewall 109. An opening 205 is provided at the other end of the peripheral sidewall 109 opposite to the end wall 111, and a cover plate 220 covers the opening 205 of the housing 200. The cover plate 220 can be used to encapsulate the electrode assembly 120 and the electrolyte together with the housing 200. The housing 200 can be made of any of a variety of available materials, such as copper, iron, aluminum, steel, or aluminum alloy. The housing 200 can be cylindrical and define a receiving cavity in which the electrode assembly 120 is disposed. The outer diameter of the housing 200 can be determined according to the specific diameter of the electrode assembly 120; for example, the outer diameter of the housing 200 can be, for example, 18 mm, 21 mm, or 46 mm. In some embodiments, the secondary battery 100 may be a 4680 cylindrical battery (outer diameter 46mm, height 80mm), or a 4695 cylindrical battery (outer diameter 46mm, height 95mm), or a 46120 cylindrical battery (outer diameter 46mm, height 120mm).

[0030] The electrode assembly 120 can be formed primarily by sequentially stacking and winding a positive electrode sheet, a negative electrode sheet, and a separator located between the positive and negative electrode sheets. The wound electrode assembly 120 can have a winding center hole 120c. In some embodiments, the positive electrode sheet may include a positive current collector and a positive active material layer, the positive active material layer being coated on a portion of the surface of the positive current collector. The uncoated area of ​​the positive current collector not covered by the positive electrode coating area is used to form a positive electrode tab 125. The negative electrode sheet may include a negative current collector and a negative active material layer, the negative active material layer being coated on a portion of the surface of the negative current collector. The uncoated area of ​​the negative current collector not covered by the negative electrode coating area is used to form a negative electrode tab 124.

[0031] An inwardly protruding groove 113 (also referred to as a crimping portion) is formed on the peripheral sidewall of the housing 200 near the opening 205. An electrode assembly 120 is disposed between the end wall 111 and the groove 113, and the groove 113 restricts the movement of the electrode assembly 120 in the height direction D1 and the opposite direction of the secondary battery between the end wall 111 and the groove 113. The direction from the opening 205 to the end wall 111 is the height direction D1 (also referred to as the first direction). The end of the peripheral sidewall 109 of the housing 200 on the opening 205 side can be configured as a rolled edge portion 32, which extends inward along a second direction D2 (i.e., the radial direction of the housing 200) perpendicular to the height direction D1. The rolled edge portion 32 and the groove 113 are spaced apart along the height direction D1, and the groove 113 and the rolled edge portion 32 can jointly clamp the cover plate 220. The cover plate 220 is electrically insulated from the housing 200.

[0032] The negative electrode tab 124 of the electrode assembly 120 faces the opening 205 and can be electrically connected to the housing 200 via a negative electrode current collector 201 located between the cover plate 220 and the electrode assembly 120, thereby making the housing 200 negatively charged. The negative electrode current collector 201 can be welded to the housing 200 by laser welding. Specifically, the welding position of the negative electrode current collector 201 to the housing 200 is located on the side of the groove 113 facing the electrode assembly 120.

[0033] The secondary battery 100 may further include a terminal post 160, which passes through and is insulated from the end wall 111. The terminal post 160 can be electrically connected to the positive electrode tab 125 of the electrode assembly 120 via a positive current collector 202 located between the terminal post 160 and the electrode assembly 120, thereby making the terminal post 160 positively charged. In some embodiments, the terminal post 160 can be welded to the positive current collector 202 by laser penetration welding.

[0034] In one example of the secondary battery 100 of the present invention, the method for manufacturing the secondary battery 100 of the present invention includes the following steps:

[0035] Winding: A winding structure formed by stacking and winding negative electrode sheet, separator and positive electrode sheet, the uncoated part of the negative current collector of negative electrode sheet and the positive current collector of positive electrode sheet is used as positive electrode tab 125 and negative electrode tab 124, and the positive electrode tab 125 and negative electrode tab 124 are bent along the radial direction of electrode assembly 120.

[0036] Welding of current collectors to electrode assemblies: The positive current collector 202 and the negative current collector 201 are welded to the surface areas of the bent positive electrode tab 125 and the negative electrode tab 124, respectively.

[0037] Installation into the housing: The electrode assembly 120, which has been welded to the negative current collector 201 and the positive current collector 202, is installed into the housing 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.

[0038] Install pole 160.

[0039] Electrolyte injection: The method of electrolyte injection is not limited, and injection can be carried out through opening 205. In this embodiment, electrolyte is injected through opening 205, which reduces the step of opening an injection hole in the end wall 111. The existing opening 205 can be used directly for injection, simplifying the process and reducing costs.

[0040] Sealing: The cover plate 220 is sealed and installed on the opening 205. There are various sealing methods, and this is not limited to one. In some embodiments, a rolling groove 113 recessed towards the inside of the housing 200 is first formed on the outer periphery of the housing 200 to restrict the movement of the electrode assembly 120 along the height direction D1. Then, a mechanical sealing process is used to press and seal the housing 200 to form a rolled edge 32, thereby sealing and installing the cover plate 220 on the opening 205 of the housing 200. This step is a mature process, low in cost, and highly efficient.

[0041] Figure 4 yes Figure 3 A magnified view of a portion of region A1 in the diagram. (Reference) Figure 4 As shown, the groove 113 includes two straight portions 113a and 113b extending toward the interior of the housing 200 along a second direction D2 perpendicular to the height direction D1, and a bent portion 113c connecting the two straight portions 113a and 113b. The ends of the two straight portions 113a and 113b facing into the housing are connected by the bent portion 113c.

[0042] Figure 5 yes Figure 3 and Figure 4 A magnified view of a portion of the groove. (Combined with...) Figure 4 and Figure 5 As shown, two straight portions 113a and 113b are arranged opposite each other in the height direction D1, and the minimum distance between the two straight portions 113a and 113b in the height direction D1 is H1. The minimum distance H1 is the minimum distance between the opposing surfaces of the two straight portions 113a and 113b. In some embodiments, the minimum distance H1 satisfies 0.2mm ≤ H1 ≤ 1mm.

[0043] There are two existing methods for sealing the negative electrode side of battery casings (such as steel casings): laser sealing and jacking sealing using a grooving structure. Laser sealing has particularly high process requirements. Jacking sealing is a relatively mature process, but it also has some other safety hazards. For example, the casing at the grooving point is under tension, and there is a risk that the nickel layer inside the casing at the grooving point may peel off, thereby increasing the risk of foreign objects inside the cell. If the minimum distance H1 between the two straight parts 113a and 113b of the grooving 113 is too small, the casing at the grooving point may break, for example, the nickel layer may easily peel off, which may increase the risk inside the cell. At the same time, damage to the outer surface of the casing will also reduce the rust resistance of the outer layer. If the minimum distance H1 is too large, it may reduce the structural strength of the casing at the grooving point. In the embodiments of this application, the minimum distance H1 between the two straight portions 113a and 113b of the groove 113 is set to a range of 0.2mm≤H1≤1mm. This can effectively prevent damage to the inside and outside of the casing at the groove (such as nickel layer peeling), reduce the internal risk of the cell, and improve the rust resistance of the casing. It can also make the casing have sufficient strength at the groove, thereby improving the sealing and safety performance of the battery.

[0044] In some embodiments, the outer surface of the peripheral sidewall 109 defines a groove 115 by a groove 113, the groove 115 having a depth L1, which may also be referred to as the depth of the groove 113. Along a second direction D2 perpendicular to the height direction D1, the depth L1 is the distance from the outer surface 109s of the peripheral sidewall 109 to the inner edge 113e of the bend 113c of the groove 113. The inner edge 113e is the edge of the groove 113 that is furthest from the outer surface 109s of the peripheral sidewall 109 on the surface of the groove 113 that defines the groove 115.

[0045] In some embodiments, the depth L1 of the groove 113 can be greater than or equal to 3 mm and less than or equal to 4.0 mm, i.e., 3 mm ≤ L1 ≤ 4 mm. The depth L1 of the groove 113 also affects the peeling of the nickel layer of the casing and the internal space of the steel casing. If the depth L1 is greater than 4.0 mm, the groove depth will be too large and more likely to cause casing damage. If the depth L1 is less than 3 mm, the welding area between the negative electrode current collector 201 and the groove 113 will be reduced, which will increase the overcurrent and reduce battery performance. By configuring the depth L1 of the groove 113 to be 3 mm ≤ L1 ≤ 4 mm, casing damage (such as nickel layer peeling) at the groove can be further avoided, the strength of the casing at the groove can be improved, the sealing and safety performance of the battery can be improved, the internal space of the casing can be saved, and sufficient welding area can be provided between the negative electrode current collector 201 and the groove 113 to ensure battery performance.

[0046] In some embodiments, the ratio of the minimum spacing H1 between the two straight portions 113a and 113b of the groove 113 to the depth L1 of the groove 113 satisfies 5% ≤ H1 / L1 ≤ 33%. If H1 / L1 exceeds this ratio range, the minimum spacing H1 or the depth L1 of the groove 113 will be relatively too large or too small. By optimizing the ratio of the minimum spacing H1 to the depth L1 of the groove 113 to 5% ≤ H1 / L1 ≤ 33%, a balance can be achieved between avoiding shell damage at the groove, ensuring the structural strength at the groove, and ensuring sufficient welding area between the groove and the negative electrode current collector. This achieves the effects of avoiding shell damage at the groove, improving the structural strength at the groove, and providing sufficient welding area.

[0047] In some embodiments, the minimum thickness A of the portion of the peripheral sidewall 109 forming the groove 113 is greater than 0.3 mm, and the ratio of the minimum thickness A to the maximum thickness of the peripheral sidewall 109 is ≥70%, i.e., A / maximum thickness of the peripheral sidewall ≥70%. In other words, the minimum tensile wall thickness A of the housing at the groove 113 is >0.3 mm and not less than 70% of the maximum thickness of the peripheral sidewall 109. If the wall thickness at the groove 113 is too thin, the strength is insufficient, the housing is prone to breakage, and the housing is prone to shattering during thermal runaway. By configuring the minimum thickness A >0.3 mm and A / maximum thickness of the peripheral sidewall ≥70%, sufficient strength can be provided to the groove structure to prevent housing breakage and shattering during thermal runaway, thus ensuring battery safety.

[0048] In some embodiments, the ratio of the minimum thickness A at the groove 113 to the minimum distance H1 between the two straight portions 113a and 113b of the groove 113 satisfies 30% ≤ A / H1 ≤ 2. If A / H1 is less than 30%, the minimum thickness A may be relatively too small or the minimum distance H1 may be relatively too large, potentially resulting in insufficient strength. If A / H1 is greater than 2, the minimum thickness A may be relatively too large, increasing processing difficulty, or the minimum distance H1 may be relatively too small, making the shell at the groove prone to breakage. By optimizing the ratio of the minimum thickness A to the minimum distance H1 at the groove 113 to 30% ≤ A / H1 ≤ 2, the effect of simultaneously strengthening the shell at the groove and preventing breakage can be enhanced.

[0049] In some embodiments, the first straight portion 113a of the two straight portions 113a and 113b is located near one end of the opening 205 of the peripheral sidewall 109, and the second straight portion 113b is located near the electrode assembly 120. The first surface 1131 of the first straight portion 113a ( Figure 5 The upper surface of the middle part) faces away from the rolled edge 32, and the first surface 321 of the rolled edge 32 ( Figure 5The lower surface of the first straight portion 113a faces away from the groove 113, and the maximum distance between the first surface 1131 of the first straight portion 113a and the first surface 321 of the rolled edge portion 32 in the height direction D1 is H2.

[0050] In some embodiments, the maximum distance H2 is greater than 2 mm and less than 3 mm. If the maximum distance H2 is greater than 3 mm, it will occupy too much internal space of the casing. If the maximum distance H2 is less than 2 mm, it may also lead to casing damage at the groove and rolled edge locations, increasing the internal risk of the battery cell and reducing the rust resistance of the outer casing. In the embodiments of this application, by setting the maximum distance H2 between the rolled edge 32 and the first straight portion 113a of the adjacent groove 113 to be greater than 2 mm and less than 3 mm, it is possible to further avoid casing damage at the groove and rolled edge locations, reduce the internal risk of the battery cell, and improve the rust resistance of the casing; it also enables the casing to have sufficient strength at the groove and rolled edge locations, improving the sealing and safety performance of the battery.

[0051] Specifically, the negative electrode current collector 201 includes a first portion 201A connected to the negative electrode tab of the electrode assembly 120, and a second portion 201B connected to the periphery of the first portion 201A. The second portion 201B is connected to the groove 113. Specifically, the second portion 201B is located between the first portion 201A and the groove 113, and the second portion 201B is connected to the groove 113 through a surface facing the groove 113. The second portion 201B of the negative electrode current collector 201 can extend along a second direction D2 perpendicular to the height direction D1. This can minimize the size of the negative electrode current collector 201 in the height direction D1, thereby reducing the space occupied by the negative electrode current collector 201 within the housing.

[0052] More specifically, the second portion 201B of the negative current collector 201 can be welded to the surface of the second straight portion 113b facing the electrode assembly. Along the second direction D2, from the peripheral sidewall 109 into the housing 200, the second portion 201B has an end 201e away from the first portion 201A. In some embodiments, along the second direction D2, one end 201e of the second portion 201B does not extend beyond one end 113f of the groove 113. This facilitates the welding of the negative current collector 201 to the groove 113.

[0053] Furthermore, one end 201e of the second portion 201B of the negative electrode current collector 201 can be positioned above the bent portion 113c of the groove 113 along the height direction D1. That is, one end 201e of the second portion 201B extends beyond the second straight portion 113b of the groove 113, but does not extend beyond the bent portion 113c of the groove 113. This ensures that the welding area between the second portion 201B of the negative electrode current collector 201 and the second straight portion 113b of the groove 113 can be maximized. The increased welding area also reduces overcurrent, thereby improving battery performance.

[0054] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A secondary battery, characterized in that, include: A housing, the housing including a peripheral sidewall and an end wall connected to one end of the peripheral sidewall, the other end of the peripheral sidewall having an opening, and an inwardly protruding groove provided on the peripheral sidewall adjacent to the opening; An electrode assembly is housed within the housing and located between the end wall and the groove; The height direction of the secondary battery is a first direction, and the groove includes two straight portions extending into the interior of the housing along a second direction perpendicular to the first direction, and a bent portion connecting the two straight portions. The two straight sections are arranged opposite each other in the first direction, and the minimum distance H1 between the two straight sections in the first direction satisfies 0.2mm≤H1≤1mm.

2. The secondary battery according to claim 1, characterized in that, The outer surface of the peripheral sidewall defines a groove by the roller groove, wherein the depth L1 of the groove satisfies 3mm≤L1≤4mm, and the depth L1 is the distance from the outer surface of the peripheral sidewall to the inner edge of the bend of the roller groove along the second direction.

3. The secondary battery according to claim 1, characterized in that, The minimum thickness A of the portion of the peripheral sidewall forming the groove is greater than 0.3 mm, and the ratio of the minimum thickness A to the maximum thickness of the peripheral sidewall is ≥70%.

4. The secondary battery according to claim 2, characterized in that, The ratio of the minimum spacing H1 to the depth L1 satisfies 5% ≤ H1 / L1 ≤ 33%.

5. The secondary battery according to claim 3, characterized in that, The ratio of the minimum thickness A to the minimum spacing H1 satisfies 30% ≤ A / H1 ≤ 2.

6. The secondary battery according to claim 1, characterized in that, The first of the two straight sections is located near the other end of the peripheral sidewall. The other end of the peripheral sidewall forms a rolled edge extending in the second direction toward the interior of the housing on the side of the groove opposite to the electrode assembly. Wherein, the first surface of the first straight portion faces away from the rolled edge portion, the first surface of the rolled edge portion faces away from the rolling groove, and the maximum distance H2 between the first surface of the first straight portion and the first surface of the rolled edge portion in the first direction satisfies 2mm≤H2≤3mm.

7. The secondary battery according to claim 2, characterized in that, Also includes: A first collector plate is located on the side of the electrode assembly facing the opening. The first collector plate includes a first portion electrically connected to the electrode assembly and a second portion connected to the groove. Wherein, along the second direction from the peripheral sidewall into the interior of the housing, the end of the second portion away from the first portion does not extend beyond the end of the groove.

8. The secondary battery according to claim 7, characterized in that, The second part is located above the bend in the groove along the first direction.

9. A battery pack, characterized in that, Includes the secondary battery as described in any one of claims 1-8.

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

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