Battery cover and secondary battery

Abstract

This application discloses a battery cover and a secondary battery. The battery cover includes: a cover body with an electrode hole defined by a side wall of the cover body; an electrode that passes through the electrode hole and is insulated from the cover body, with a first flange at one end of the electrode along the axial direction of the electrode hole; and a sealing ring located between the first flange and the bottom wall of the cover body facing the first flange, extending into the electrode hole and located between the electrode and the side wall of the cover body. The bottom wall and the side wall of the cover body are connected by a transition area, which is a non-right-angled surface structure. This technical solution can at least reduce the risk of sealing ring tearing and sealing failure.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cover and a secondary battery. Background Technology

[0002] In the field of new energy power batteries, with the increasing maturity of secondary battery technology (such as lithium batteries), secondary batteries are widely used as power batteries in electric vehicles and energy storage, and the requirements for the performance and safety of secondary batteries are becoming increasingly stringent. Among them, the battery cover, as a component of the secondary battery, firstly seals the internal and external environments by welding it to the casing; secondly, it connects the internal and external circuits, transmitting the internal current of the battery to the outside through the top cover terminals, thus acting as a current conductor.

[0003] The battery cover of a secondary battery is generally constructed by riveting together the terminals, sealing ring, upper plastic, lower plastic, and the cover body (e.g., a sheet of aluminum). The sealing ring in existing battery covers is prone to tearing under stress, affecting its sealing performance. Utility Model Content

[0004] To address the above issues, this application proposes a battery cover and a secondary battery, which can at least reduce the risk of sealing ring tearing and sealing failure.

[0005] According to one aspect of this application, a battery cover is provided, comprising: a cover body having a terminal hole defined by a side wall of the cover body; a terminal passing through the terminal hole and insulated from the cover body, the terminal having a first flange at one end along the axial direction of the terminal hole; and a sealing ring located between the first flange and a bottom wall of the cover body facing the first flange, extending into the terminal hole and located between the terminal and the side wall of the cover body, the bottom wall and the side wall of the cover body being connected by a transition area, the transition area being a non-right-angle surface structure.

[0006] In some embodiments, the battery cover further includes an upper plastic material disposed on the side of the cover body opposite to the first flange, and which overlaps and abuts against the sealing ring in an axial projection with at least a portion thereof.

[0007] In some embodiments, the transition zone is a rounded corner connecting the bottom wall and the side wall of the cover plate body, the radius of the rounded corner is R1, R1 > 0.2 mm, the distance between the end of the side wall away from the first flange and the bottom wall is b2, wherein the radius R1 ≤ b2; the overlap width of the area where the cover plate body and the sealing ring overlap in the axial direction in the radial direction of the pole hole is W1, and the radial width of the rounded corner is S1, wherein the difference between W1 and S1 is b3, b3 ≥ 0.8 mm.

[0008] In some embodiments, the transition zone is a chamfered angle connecting the bottom wall and the side wall of the cover plate body. The axial dimension of the chamfered angle is T1, where T1 ≥ 0.1 mm. The chamfered angle has a first end away from the first flange. The distance between the first end and the end of the side wall away from the first flange along the axial direction is c2, where c2 > 0.

[0009] In some embodiments, the chamfered corner also has a second end near the first flange, and is connected to the bottom wall of the cover plate body at the first end and the second end respectively through side wall fillets and bottom wall fillets, the radii of the side wall fillets and the radii of the bottom wall fillets are R2 and R3 respectively, wherein 0.1mm≤R2≤T1×1 / 2 and 0.1mm≤R3≤T1×1 / 2.

[0010] In some embodiments, the area where the cover plate body and the sealing ring overlap in the axial direction has an overlap width of W1 in the radial direction of the pole hole, a chamfer width of S2 in the radial direction, and the difference between W1 and S2 is c3, where c3 ≥ 0.8 mm.

[0011] In some embodiments, the transition zone is a right-angle notch, the axial height of the right-angle notch is d1, the compression height of the sealing ring formed by the cover plate body abutting against the sealing ring is T2, 0.1mm≤d1≤T2, and the radial width of the right-angle notch in the pole hole is d3, d3≥0.1mm.

[0012] In some embodiments, the right-angle notch includes a first notch sidewall and a second notch sidewall connected at right angles. The first notch sidewall extends radially along the pole post hole, and the second notch sidewall extends axially. The first notch sidewall is connected to the sidewall of the cover plate body through a sidewall fillet, and the second notch sidewall is connected to the bottom wall of the cover plate body through a bottom wall fillet. The radii of the sidewall fillet and the bottom wall fillet are R4 and R5, respectively, where 0.1mm≤R4≤d1 or 0.1mm≤R4≤d3, 0.1mm≤R5≤d1 or 0.1mm≤R5≤d3.

[0013] In some embodiments, the area where the cover plate body and the sealing ring overlap in the axial direction is W1 in the radial direction of the pole hole, and the difference between W1 and d3 is d2, where d2 ≥ 0.8 mm.

[0014] In some embodiments, the cover plate body is a sheet of plain aluminum.

[0015] According to another aspect of this application, a secondary battery is provided, comprising: an electrode assembly and an electrolyte; a housing having an opening; and the aforementioned battery cover, which covers the opening to enclose the electrode assembly and electrolyte within the housing.

[0016] The beneficial technical effects of this utility model include:

[0017] By using a transition zone with a non-right-angled surface structure to connect the bottom wall and side wall of the cover plate body, and replacing the right-angled surface structure at the corner of the bottom wall and side wall of the cover plate body with this transition zone, the stress concentration at the corner of the bottom wall and side wall can be reduced, the risk of the sealing ring being torn due to stress can be reduced, and the sealing ring can be prevented from failing. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional schematic diagram of an existing battery cover.

[0020] Figure 2A This is a cross-sectional schematic diagram of the battery cover plate according to an embodiment of this application.

[0021] Figure 2B yes Figure 2A A partially enlarged schematic diagram of the junction between the central sealing ring and the cover plate body.

[0022] Figure 3A This is a cross-sectional schematic diagram of a battery cover according to another embodiment of this application.

[0023] Figure 3B According to one embodiment Figure 3A A partially enlarged schematic diagram of the junction between the central sealing ring and the cover plate body.

[0024] Figure 3C According to another embodiment Figure 3A A partially enlarged schematic diagram of the junction between the central sealing ring and the cover plate body.

[0025] Figure 4A This is a cross-sectional schematic diagram of a battery cover according to another embodiment of this application.

[0026] Figure 4B According to one embodiment Figure 4A A partially enlarged schematic diagram of the junction between the central sealing ring and the cover plate body. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0028] The following disclosure provides numerous different embodiments or instances for implementing various features of the provided subject matter. Specific examples of elements and arrangements will be described below to simplify the present invention. These are merely examples and are not intended to limit the present invention. For example, in the following description, forming a first component above or on a second component may include embodiments where the first and second components are in direct contact, or embodiments where an additional component is formed between the first and second components such that the first and second components are not in direct contact. Furthermore, reference numerals and / or letters may be repeated in various instances of the present invention. Such repetition is merely for brevity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0029] Furthermore, where there is no conflict, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] See Figure 1 As shown, in the existing battery top cover, the terminal 18 is fixedly connected to the aluminum sheet 10, and the aluminum sheet 10 abuts against the sealing ring 30. During the development of large energy storage cells, the temperature of the positive and negative terminals can reach over 400°C during short-circuit testing, while the melting point of the fluororubber sealing ring 30 is typically around 300°C. Therefore, when the terminal temperature exceeds 400°C for a short period, the sealing ring 30 will soften due to the high temperature. Combined with the compression of the sealing ring 30 by the aluminum sheet 10, stress concentration at the corner 12 can easily cause the sealing ring 30 to tear obliquely 34 under stress and heat. If the upper plastic 50 melts at this time, the compressed sealing ring 30 will rebound towards the upper plastic 50, greatly increasing the probability of battery leakage.

[0031] In view of the above-mentioned technical problems, embodiments of this application provide a battery cover. Figure 2A This is a cross-sectional schematic diagram of the battery cover according to an embodiment of this application. See also... Figure 2A As shown, the battery cover 100 may include a cover body 110 and a terminal post 180. The cover body 110 has a terminal post hole 110v, which is defined by a side wall 112 of the cover body 110. The terminal post hole 110v may be a circular through hole passing through the cover body 110, and the terminal post hole 110v may have an axis Ax. The side wall 112 may extend along the axis Ax. The terminal post 180 passes through the terminal post hole 110v and is insulated from the cover body 110.

[0032] Specifically, the terminal 180 may include a first flange 182. The cover body 110 includes a bottom wall 110b facing the first flange 182 and a top wall 110t facing away from the first flange 182. In a secondary battery, the top wall 110t of the cover body 110 may be the side facing the outside of the secondary battery casing, and the bottom wall 110b may be the side facing the inside of the casing. The sealing ring 130 is located between the first flange 182 and the bottom wall 110b of the cover body 110, and extends into the terminal hole 110v, and is located between the terminal 180 and the side wall 112 of the cover body 110.

[0033] In some embodiments, the pole post 180 may further include a columnar portion 181 and a second flange 183. The columnar portion 181 extends through the pole post hole 110v along the axis Ax. A first flange 182 and a second flange 183 are connected to opposite ends of the columnar portion 181 along the axis Ax. The first flange 182 and the second flange 183 may each extend radially beyond the pole post hole 110v. In this embodiment, the pole post 180 can be riveted to the cover plate body 110 via the first flange 182 and the second flange 183. In other embodiments, the pole post 180 may be other structures that are fixedly connected to the cover plate body 110 via the first flange 182.

[0034] The battery cover 100 may further include an upper plastic 150 and a lower plastic 140 to insulate the terminal post 180 from the cover body 110. The upper plastic 150 may be sandwiched between the top wall 110b of the cover body 110 and the second flange 183 to isolate the second flange 183 from the cover body 110. The upper plastic 150 may be arranged annularly around the terminal post 180. The lower plastic 140 may be sandwiched between the bottom wall 110b of the cover body 110 and the first flange 182 to isolate the first flange 182 from the cover body 110. The lower plastic 140 may be arranged annularly around the terminal post 180. In some embodiments, the materials of the upper plastic 150 and the lower plastic 140 may be one of engineering plastics such as PFA (fusible polytetrafluoroethylene), PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), PP (polypropylene), LCP (liquid crystal polymer), and ECM (epoxy molding compound). In some embodiments, the upper plastic 150 and the lower plastic 140 may be made of the same material.

[0035] Figure 2B yes Figure 2A A partially enlarged schematic diagram of the junction between the sealing ring and the cover plate body. (Combined with...) Figure 2A and Figure 2BAs shown, the bottom wall 110b and side wall 112 of the cover plate body 110 are connected by a transition area with a non-right-angled surface structure. Here, a non-right-angled surface structure means that the transition area is not a right-angled surface structure formed by the direct contact of the bottom wall 110b and side wall 112. This non-right-angled surface structure of the transition area replaces the original right-angled surface structure formed at the corner of the bottom wall 110b and side wall 112. In this embodiment, the transition area is a rounded corner 114 (also called a chamfered R-angle) that connects the bottom wall 110b and side wall 112.

[0036] By setting a rounded corner 114 to transition between the bottom wall 110b and the side wall 112 of the cover plate body 110, the rounded corner 114 replaces the original right-angled surface structure formed by the bottom wall 110b and the side wall 112, which can reduce the stress concentration at the corner of the bottom wall 110b and the side wall 112, reduce the risk of the sealing ring 130 being torn due to stress, and prevent the sealing ring 130 from failing to seal.

[0037] In some embodiments, the radius R1 of the fillet 114 is greater than 0.2 mm. If R1 is less than 0.2 mm, the stress at the corner between the bottom wall 110b and the side wall 112 may still be relatively concentrated. By setting the fillet 114 to a larger fillet with a radius R1 greater than 0.2 mm, the stress concentration at the corner between the bottom wall 110b and the side wall 112 can be effectively reduced, thus reducing the risk of the sealing ring 130 being torn due to stress.

[0038] In this embodiment, the sealing ring 130 may include a first sealing section 131 and a second sealing section 132 connected to the first sealing section 131. The first sealing section 131 passes through the pole hole 110v and spaced between the columnar portion 181 of the pole 180 and the side wall 112 of the cover body 110. The second sealing section 132 is disposed between the first flange 182 and the bottom wall 110b of the cover body 110. Since the pole 180 and the cover body 110 are connected by riveting, for example, the second sealing section 132 can be clamped between the first flange 182 and the bottom wall 110b.

[0039] In this embodiment, the end 112a of the side wall 112 near the second flange 183 can be connected to the top wall 110t via a chamfered angle 116 (also known as a chamfered angle). In this embodiment, the distance between the end 112a of the top wall 112 and the bottom wall 110b is b2, and the radius R1 ≤ b2. In other embodiments, the end 112a of the side wall 112 can be directly connected to the top wall 110t without a chamfered angle. In such embodiments, the radius R1 of the fillet 114 is still not greater than the distance between the end 112a of the top wall 112 and the bottom wall 110b, which is the wall thickness b1 of the cover body 110 between the first flange 182 and the second flange 183. The wall thickness b1 can refer to the maximum wall thickness of the cover body 110 between the first flange 182 and the second flange 183.

[0040] The upper plastic 150 can project onto at least a portion of the first sealing segment 131 in the axial direction Ax, and abut against and press against the first sealing segment 131, thereby compressing the first sealing segment 131. In some cases, such as when the upper plastic 150 melts due to heat, the compressed sealing ring 130 will rebound towards the upper plastic 150. Since a rounded corner 114 is provided between the bottom wall 110b and the side wall 112 of the cover body 110, the risk of the sealing ring 130 being torn due to stress is reduced. Therefore, when the sealing ring 130 rebounds towards the upper plastic 150, the sealing ring 130 will not fail to seal.

[0041] In some embodiments, the cover plate body 110 is a smooth aluminum sheet. Smooth aluminum sheets have good electrical conductivity and can be effectively used for current transmission and distribution.

[0042] The cover plate body 110 and the second sealing section 132 have an area that overlaps projectedly in the axial direction Ax, and the cover plate body 110 presses against the second sealing section 132, wherein there must be no gap between the cover plate body 110 and the second sealing section 132 to satisfy the volume space after the sealing ring is compressed. The projected overlapping area of ​​the cover plate body 110 and the second sealing section 132 has an overlap width W1 in the radial direction. The radius of the fillet 114 is S1 in the radial direction. In some embodiments, the difference between the overlap width W1 and the width S1 is b3, where b3 ≥ 0.8 mm. That is, at least 0.8 mm of the straight portion of the cover plate body 110 is guaranteed to overlap with the projection of the second sealing section 132 outside the fillet 114. The value range of b3 ≥ 0.8 mm can ensure sufficient compression of the sealing ring 130.

[0043] Figure 3A This is a cross-sectional schematic diagram of a battery cover according to another embodiment of this application. Figure 3B According to one embodiment Figure 3A A partially enlarged schematic diagram of the junction between the central sealing ring and the cover plate body. Figure 3A and Figure 3B The embodiments shown are in several aspects and are consistent with the above references. Figures 2A to 2B The described embodiments are the same or similar, and the following mainly describes them. Figure 3A and Figure 3B The differences between the illustrated embodiments are as follows.

[0044] Combination Figure 3A and Figure 3BAs shown, the transition area between the bottom wall 110b and the side wall 112 of the cover body 110 is a chamfered angle 214, and the bottom wall 110b and the side wall 112 are connected by the chamfered angle 214. The chamfered angle 214 can also be called a chamfered C-angle. By connecting the bottom wall 110b and the side wall 112 of the cover body 110 with the chamfered angle 214, the chamfered angle 214 replaces the original right-angled surface structure formed by the bottom wall 110b and the side wall 112, which can reduce the stress concentration at the corner of the bottom wall 110b and the side wall 112, reduce the risk of the sealing ring 130 being torn due to stress, and prevent the sealing ring 130 from failing to seal. When the upper plastic 150 is heated and melts, and the sealing ring 130 rebounds towards the upper plastic 150, the sealing ring 130 will not fail to seal.

[0045] In some embodiments, the chamfer angle 214 has a dimension T1 in the direction of axis Ax, where T1 ≥ 0.1 mm. The chamfer angle 214 has a first end 214a near the second flange 183 and a second end 214b near the first flange 182. The dimension T1 of the chamfer angle 214 can be the distance between the first end 214a and the second end 214b in the direction of axis Ax. In some embodiments, the angle A1 of the chamfer angle 214 relative to the extension line of the bottom wall 110b is in the range of 30° to 60°, for example, the angle A1 can be 30°, 45° or 60°.

[0046] In this embodiment, the end 112a of the sidewall 112 near the second flange can be connected to the top wall 110t via a chamfer 116. In this embodiment, the distance between the first end 214a of the chamfer 214 and the end 112a of the sidewall 112 is c2, where c2 > 0. In other embodiments, the end 112a of the sidewall 112 can be directly connected to the top wall 110t without a chamfer. In such an embodiment, the distance between the first end 214a of the chamfer 214 and the end 112a of the sidewall 112 is equal to c1, where c1 > 0.

[0047] The cover body 110 and the second sealing section 132 have an overlapping area projected in the axial direction Ax, and this overlapping area has a radial overlap width W1. The width of the chamfer 214 in the radial direction is S2, and the difference between the overlap width W1 and the width S2 is c3. In some embodiments, c3 ≥ 0.8 mm, which ensures that the cover body 110 has sufficient compression on the sealing ring 130. There is no gap between the cover body 110 and the second sealing section 132 to accommodate the volume space after the sealing ring is compressed.

[0048] Figure 3C According to another embodiment Figure 3A A partially enlarged schematic diagram of the junction between the sealing ring and the cover plate body. (See attached diagram) Figure 3CAs shown, in some embodiments, the first end 214a of the beveled angle 214 is connected to the side wall 112 of the cover plate body 110 via a side wall fillet 2142, and the second end 214b is connected to the bottom wall 112b of the cover plate body 110 via a bottom wall fillet 2144. The radius of the side wall fillet 2142 is R2, and in some embodiments, R2 ≥ 0.1 mm. The radius of the bottom wall fillet 2144 is R3, and in some embodiments, R3 ≥ 0.1 mm, to meet the process capability for deburring.

[0049] In some embodiments, the size of the chamfer 214 in the direction of axis Ax is T1, the radius R2 of the side wall fillet 2142 satisfies 0.1mm≤R2≤T1×1 / 2, and the radius R3 of the bottom wall fillet 2144 satisfies 0.1mm≤R3≤T1×1 / 2.

[0050] In this embodiment, since the chamfered angle 214 has a sidewall fillet 2142 and a bottom wall fillet 2144 at its first end 214a and second end 214b respectively, the radial width of the chamfered angle 214 includes the radial widths of the sidewall fillet 2142 and the bottom wall fillet 2144. The overlap width of the projected area of ​​the cover plate body 110 and the second sealing section 132 is W1, the width of the chamfered angle 214 is S2, and the difference between the overlap width W1 and the width S2 is c3, where c3 does not include the width of the bottom wall fillet 2144. In some embodiments, c3 ≥ 0.8 mm to ensure that at least 0.8 mm of the straight portion of the cover plate body 110 overlaps with the projected area of ​​the second sealing section 132, ensuring that the cover plate body 110 has sufficient compression on the sealing ring 130.

[0051] Figure 4A This is a cross-sectional schematic diagram of a battery cover according to another embodiment of this application. Figure 4B According to one embodiment Figure 4A A partially enlarged schematic diagram of the junction between the central sealing ring and the cover plate body. Figure 4A and Figure 4B The embodiments shown are in several aspects and are consistent with the above references. Figures 2A to 2B The described embodiments are the same or similar, and the following mainly describes them. Figure 4A and Figure 4B The differences between the illustrated embodiments are as follows.

[0052] Combination Figure 4A and Figure 4BAs shown, in this embodiment, the transition area between the bottom wall 110b and the side wall 112 of the cover body 110 is a right-angle notch 314. The right-angle notch 314 refers to a right-angled recess at the corner of the bottom wall 110b and the side wall 112, which removes or replaces the original right-angled surface structure formed by the bottom wall 110b and the side wall 112. In this embodiment, the right-angle notch 314 between the bottom wall 110b and the side wall 112 may include a first notch side wall 314a and a second notch side wall 314b connected at a right angle, wherein the first notch side wall 314a extends radially, and the second notch side wall 314b extends along the axis Ax. By connecting the bottom wall 110b and the side wall 112 of the cover body 110 through the right-angle notch 314, stress concentration at the corner of the bottom wall 110b and the side wall 112 can be reduced, lowering the risk of the sealing ring 130 being torn due to stress and preventing sealing failure of the sealing ring 130. When the upper plastic 150 is heated and melts, and the sealing ring 130 rebounds towards the upper plastic 150, the sealing ring 130 will not fail to seal.

[0053] There is no gap between the cover plate body 110 and the second sealing section 132 to accommodate the volume space after the sealing ring is compressed. The second sealing section 132 can be compressed by the cover plate body 110, and the compressed height of the second sealing section 132 is T2. The right-angle notch 314 has a height d1 in the axial direction Ax and a radial width d3, and the compressed height of the second sealing section 132 is T2. In some embodiments, 0.1mm ≤ d1 ≤ T2. In some embodiments, d3 ≥ 0.1mm. In some embodiments, the height d1 and width d3 of the right-angle notch 314 can be the same, or the height d1 and width d3 can be different.

[0054] In some embodiments, the first notch sidewall 314a is connected to the sidewall 112 of the cover plate body 110 via a sidewall fillet 3142, and the second notch sidewall 314b is connected to the bottom wall 110b of the cover plate body 110 via a bottom wall fillet 3144. In some embodiments, the radius of the sidewall fillet 3142 is R4, 0.1mm≤R4≤d1 or 0.1mm≤R4≤d3, and this range of radius R4 can satisfy the process capability for deburring. The radius of the bottom wall fillet 3144 is R5, 0.1mm≤R5≤d1 or 0.1mm≤R5≤d3, and this range of radius R5 can satisfy the process capability for deburring.

[0055] The area where the cover body 110 and the second sealing section 132 project and overlap in the direction of axis Ax has an overlap width W1. The difference between the overlap width W1 and the width d3 is d2, where the difference d2 does not include the width of the bottom wall fillet 3144. In some embodiments, the difference d2 ≥ 0.8 mm to ensure that at least 0.8 mm of the straight portion of the cover body 110 projects and overlaps with the second sealing section 132, ensuring that the cover body 110 has sufficient compression on the sealing ring 130.

[0056] In the process of forming the battery cover 100, the battery cover 100 can be formed through the following steps: the cover body 110 (such as a plain aluminum sheet) can be processed by stamping or machining, for example, by chamfering to form the aforementioned rounded corner 114, beveled corner 214, or right-angle notch 314; then, through an assembly process, various components such as the cover body 110, terminal post 180, upper plastic 150, lower plastic 140, and sealing ring 130 are assembled together. In the formed battery cover 100, because the cover body 110 has a large rounded corner 114, the stress of compressing the sealing ring 130 will not concentrate at the rounded corner 114, and at the same time, it can also ensure that the compression amount of the sealing ring 130 meets the requirements.

[0057] Embodiments of this application also provide a secondary battery, which may include: an electrode assembly and an electrolyte, a housing with an opening, and the aforementioned battery cover. The battery cover may be disposed at the opening to enclose the electrode assembly and electrolyte within the housing. A transition zone with a non-right-angled surface structure connects the bottom wall and side wall of the cover body, reducing stress concentration at the corners of the bottom and side walls, lowering the risk of the sealing ring tearing due to stress, and preventing sealing ring failure. When the upper plastic melts due to heat and the sealing ring rebounds towards the upper plastic, the sealing ring will not fail, thereby preventing electrolyte leakage due to sealing ring failure.

[0058] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cover, characterized in that, include: The cover plate body has an electrode post hole, which is defined by the side wall of the cover plate body; A pole post, passing through the pole post hole and insulated from the cover plate body, has a first flange at one end along the axial direction of the pole post hole; and A sealing ring is located between the first flange and the bottom wall of the cover plate body facing the first flange, and extends into the pole hole and is located between the pole and the side wall of the cover plate body. The bottom wall and the side wall of the cover plate body are connected by a transition area, which is a non-right-angle surface structure.

2. The battery cover according to claim 1, characterized in that, Also includes: The upper plastic is disposed on the side of the cover plate body opposite to the first flange, and overlaps with and abuts the sealing ring in the axial direction at least a portion thereof.

3. The battery cover according to claim 1, characterized in that, The transition zone is the rounded corner connecting the bottom wall and the side wall of the cover plate body, and the radius of the rounded corner is R1, where R1 > 0.2 mm. The distance between the end of the sidewall away from the first flange and the bottom wall is b2, where the radius R1 ≤ b2; The overlap width of the area where the cover plate body and the sealing ring project in the axial direction overlap in the radial direction of the pole hole is W1, and the width of the fillet in the radial direction is S1, wherein the difference between W1 and S1 is b3, and b3≥0.8mm.

4. The battery cover according to claim 1, characterized in that, The transition zone is the beveled angle connecting the bottom wall and the side wall of the cover plate body. The oblique angle in the axial direction is T1, where T1 ≥ 0.1 mm. The chamfer has a first end away from the first flange, and the distance between the first end along the axial direction and the end of the sidewall away from the first flange is c2, where c2 > 0.

5. The battery cover according to claim 4, characterized in that, The chamfered angle also has a second end near the first flange, which is connected to the bottom wall of the cover plate body at the first end and the second end respectively by side wall fillets and bottom wall fillets. The radii of the side wall fillet and the radii of the bottom wall fillet are R2 and R3, respectively, wherein 0.1mm≤R2≤T1×1 / 2 and 0.1mm≤R3≤T1×1 / 2.

6. The battery cover according to claim 4, characterized in that, The area where the cover plate body and the sealing ring overlap in the axial direction has an overlap width of W1 in the radial direction of the pole hole, and the width of the chamfer in the radial direction is S2. The difference between W1 and S2 is c3, and c3 ≥ 0.8 mm.

7. The battery cover according to claim 1, characterized in that, The transition zone is a right-angled notch. The height of the right-angle notch in the axial direction is d1, and the compressed height of the sealing ring formed by the cover plate body abutting against the sealing ring is T2, where 0.1mm ≤ d1 ≤ T2. The width of the right-angle notch in the radial direction of the pole hole is d3, where d3 ≥ 0.1 mm.

8. The battery cover according to claim 7, characterized in that, The right-angle notch includes a first notch sidewall and a second notch sidewall connected at a right angle. The first notch sidewall extends radially along the pole post hole, and the second notch sidewall extends axially. The first notch sidewall is connected to the sidewall of the cover plate body via a rounded corner, and the second notch sidewall is connected to the bottom wall of the cover plate body via a rounded corner. The radii of the side wall fillets and the bottom wall fillets are R4 and R5, respectively, with 0.1mm≤R4≤d1 or 0.1mm≤R4≤d3, 0.1mm≤R5≤d1 or 0.1mm≤R5≤d3.

9. The battery cover according to claim 8, characterized in that, The overlap width of the area where the cover plate body and the sealing ring project in the axial direction overlap in the radial direction of the pole hole is W1, and the difference between W1 and d3 is d2, where d2 ≥ 0.8 mm.

10. A secondary battery, characterized in that, include: Electrode assembly and electrolyte; A housing having an opening; as well as The battery cover according to any one of claims 1-9, wherein the battery cover is disposed over the opening to enclose the electrode assembly and the electrolyte within the housing.

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