Single battery and battery pack

Abstract

The utility model provides a single battery and a battery pack, and relates to the technical field of batteries. The single battery comprises a shell, a top cover assembly and a battery cell, the shell is provided with a cavity, the battery cell is located in the cavity, the top cover assembly comprises a top cover piece, a lower insulating part and a pole, the top cover piece is provided with a first pole hole, the lower insulating part is provided with a second pole hole, and the lower insulating part comprises a first surface facing the battery cell; the lower insulating part is connected to one side, facing the battery cell, of the top cover plate; the pole comprises a bottom plate and a pole body connected to the bottom plate, the bottom plate is located in the cavity and used for being electrically connected with the battery cell, at least part of the structure of the pole body is arranged in the first pole hole and the second pole hole in a penetrating mode, and the bottom plate makes contact with the first surface; the first surface is provided with reinforcing ribs, the reinforcing ribs are arranged on the peripheral side of the bottom plate, the orthographic projection area of the bottom plate on the first surface is S1, the orthographic projection area of the reinforcing ribs on the first surface is S2, and 0.02 < = S2 / S1 < = 0.35. And the lower insulating part is not easy to deform.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a single cell and a battery pack. Background Art

[0002] The top cover assembly of the battery generally includes a top cover sheet, a lower insulating member and a pole, and the pole is connected to the lower insulating member and the top cover sheet. When the pole is subjected to a pulling force or a torsional force, the fitting portion between the lower insulating member and the pole is easily deformed. Utility Model Content

[0003] The embodiments of the present application provide a single cell and a battery pack, in which a lower insulating member is not easily deformed.

[0004] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0005] On the one hand, a single cell is provided, comprising a shell, a top cover assembly and a battery cell, wherein the shell is provided with a cavity, the battery cell is located in the cavity, the top cover assembly is covered in the cavity and fixedly connected to the shell;

[0006] The top cover assembly comprises a top cover sheet, a lower insulating member and a pole, wherein the top cover sheet is fixedly connected to the shell, the top cover sheet is provided with a first pole hole, the lower insulating member is provided with a second pole hole, the lower insulating member has a first surface facing the battery cell, and the lower insulating member is connected to a side of the top cover sheet facing the battery cell; the pole comprises a bottom plate and a column connected to the bottom plate, the bottom plate is located in the cavity for electrically connecting with the battery cell, at least part of the structure of the column is penetrated in the first pole hole and the second pole hole, and the bottom plate is located on a side of the lower insulating member facing the battery cell and contacts the first surface;

[0007] The first surface is provided with reinforcing ribs, and the reinforcing ribs are located on the peripheral side of the bottom plate, the orthographic projection area of ​​the bottom plate on the first surface is S1, and the orthographic projection area of ​​the reinforcing ribs on the first surface is S2, wherein 0.02≤S2 / S1≤0.35.

[0008] In some embodiments, 0.02≤S2 / S1≤0.15.

[0009] In some embodiments, the reinforcing rib includes a first side surface and a second side surface disposed opposite to each other, the first side surface faces the second pole hole, the second side surface is away from the second pole hole, and the minimum distance between the first side surface and the second side surface is c, wherein 0.3 mm≤c≤5 mm.

[0010] In some embodiments, the reinforcing rib includes a first side surface and a second side surface disposed opposite to each other, the first side surface faces the second pole hole, the bottom plate has an outer peripheral surface facing the reinforcing rib, and the minimum distance from the first side surface to the outer peripheral surface is L, where 0mm≤L≤0.5mm.

[0011] In some embodiments, the first surface is provided with a plurality of the reinforcing ribs, and the plurality of the reinforcing ribs are arranged at intervals along the outer circumference of the bottom plate.

[0012] In some embodiments, the lower insulating member has an intersecting first direction and a second direction, the bottom plate has two first sides extending along the first direction and two second sides extending along the second direction, the two first sides are arranged opposite to each other in the second direction, the two second sides are arranged opposite to each other in the first direction, one first side is connected to the two second sides, one second side is connected to the two first sides, and the reinforcing ribs are arranged on the outer sides of the two first sides and the two second sides.

[0013] In some embodiments, the reinforcing rib corresponding to the first side is a first reinforcing rib, and the reinforcing rib corresponding to the second side is a second reinforcing rib, the length of the first reinforcing rib along the first direction is b, and the spacing between two of the first reinforcing ribs is B, the length of the second reinforcing rib along the second direction is a, and the spacing between two of the second reinforcing ribs is A, wherein 0.2≤a / B≤1, and / or, 0.2≤b / A≤1.

[0014] In some embodiments, the reinforcing ribs arranged at corresponding positions of the two second sides have a first end and a second end opposite to each other along the second direction, and / or the reinforcing ribs arranged at corresponding positions of the two first sides have a first end and a second end opposite to each other along the first direction, and the first end and the second end are provided with a chamfered structure.

[0015] In some embodiments, the surface of the bottom plate facing the battery cell protrudes beyond the surface of the reinforcing rib facing the battery cell, and the shortest distance from the surface of the bottom plate facing the battery cell to the surface of the reinforcing rib facing the battery cell is H, wherein 0.1 mm<H<5 mm.

[0016] In some embodiments, the electrode column includes a positive electrode column and a negative electrode column, and the reinforcing rib is arranged at a position of the first surface corresponding to the positive electrode column, and the reinforcing rib is arranged on the surrounding side of the positive electrode column, and the reinforcing rib is also arranged at a position of the first surface corresponding to the negative electrode column, and the reinforcing rib is arranged on the surrounding side of the negative electrode column.

[0017] On the other hand, a battery pack is provided, comprising the above-mentioned single cell battery.

[0018] In the single cell and battery pack provided in the embodiments of the present application, the first surface of the lower insulating member is provided with reinforcing ribs, and the reinforcing ribs are located on the peripheral side of the bottom plate of the pole. By providing reinforcing ribs on the first surface of the lower insulating member, the structural strength of the lower insulating member is increased, and when the lower insulating member is subjected to the force transmitted from the pole, such as the torsional force when assembling the pole, the lower insulating member is not easily deformed or damaged. At the same time, the orthographic projection area of ​​the bottom plate on the first surface is S1, and the orthographic projection area of ​​the reinforcing ribs on the first surface is S2. When 0.02≤S2 / S1≤0.5 is satisfied, the force of deformation of the lower insulating member when subjected to torsion is greatly improved, so that the anti-deformation performance of the lower insulating member is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A cross-sectional schematic diagram of a single cell provided in an embodiment of the present application;

[0021] Figure 2 A schematic diagram of a partial structure of a single cell provided in an embodiment of the present application;

[0022] Figure 3 A schematic diagram of partial structural decomposition of a single cell provided in an embodiment of the present application;

[0023] Figure 4 A schematic cross-sectional view of a portion of the structure of a single cell provided in an embodiment of the present application;

[0024] Figure 5 A schematic cross-sectional view of a portion of the structure of a single cell provided in an embodiment of the present application;

[0025] Figure 6 A schematic diagram of a partial structure of a single cell provided in an embodiment of the present application;

[0026] Figure 7 A schematic diagram of a partial structure of a single cell provided in an embodiment of the present application;

[0027] Figure 8 A schematic diagram of a reinforcing rib in a single cell provided in an embodiment of the present application;

[0028] Fig. 9 A schematic diagram of a bottom plate in a single cell provided in an embodiment of the present application;

[0029] Fig.10 A schematic diagram of a bottom plate and reinforcing ribs in a single cell provided in an embodiment of the present application.

[0030] Reference numerals:

[0031] 100-top cover assembly;

[0032] 110- pole; 110a- positive pole; 110b- negative pole; 111- bottom plate; 112- column;

[0033] 120-top cover plate; 121-first pole hole; 122-pressure relief port;

[0034] 130 - lower insulating member; 131 - second pole hole; 132 - reinforcing rib; 132a - first reinforcing rib; 132b - second reinforcing rib; 133 - first surface; 1 - first side surface; 2 - second side surface; 3 - outer peripheral surface;

[0035] 140-explosion-proof valve;

[0036] 150-Injection port;

[0037] 160-upper insulating member;

[0038] 200-housing;

[0039] 300-battery cells. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] In the embodiments of the present application, words such as "first", "second", "third", and "fourth" are used to distinguish between identical or similar items with basically the same functions and effects. This is only for the purpose of clearly describing the technical solutions of the embodiments of the present application and shall not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0042] In the embodiments of the present application, “plurality” means two or more, and “at least one” means one or more, unless otherwise clearly and specifically defined.

[0043] In the embodiments of the present application, the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0044] The embodiment of the present application provides a battery pack, which can be a power battery pack, used in electric vehicles to provide power for the drive motor of the electric vehicle, etc. Of course, the battery pack can also be other types of battery packs, such as battery packs used in electric bicycles and electric motorcycles, etc. The embodiment of the present application does not limit the type and application scenario of the battery pack.

[0045] The battery pack includes a box body and a single cell arranged in the box body. The box body is used to protect the single cell inside and prevent the single cell from being hit. The box body may be provided with an installation cavity, and the single cell is installed in the installation cavity. The battery pack may include a plurality of single cells, and the plurality of single cells are arranged in an array. When a plurality of single cells are arranged in the box body, the plurality of single cells may be connected in series or in parallel.

[0046] The battery pack may also include a thermal management component, which is connected to the single cell to adjust the temperature of the single cell. Exemplarily, a plurality of single cells are arranged in an array, and the plurality of single cells arranged in the array form a plurality of single cell groups, each single cell group includes a plurality of single cells, and the plurality of single cells in the same battery group are arranged in sequence along a straight line, and the plurality of single cell groups are arranged at intervals along a direction perpendicular to the straight line. The thermal management component is located between two adjacent single cell groups, and one side of the thermal management component is connected to a single cell in one single cell group, and the other opposite side of the thermal management component is connected to a single cell in another single cell group.

[0047] The connection between the thermal management component and the single cell means that the heat generated by the single cell can be transferred to the thermal management component by heat transfer. The thermal management component can be in direct contact or physical connection with the single cell, or the thermal management component can be connected to the single cell through other heat-conducting media to achieve heat transfer.

[0048] In actual application, the box body may be provided with a charging interface for charging and a discharging interface for discharging, and the installation cavity in the box body may also be provided with modules such as a battery management system.

[0049] like Figure 1As shown, the single cell includes a shell 200, a top cover assembly 100 and a battery cell 300. A cavity 400 is provided in the shell 200, one end of the cavity 400 is provided with an opening, the top cover assembly 100 is sealed on the opening to seal the cavity 400, the battery cell 300 is located in the cavity 400, the top cover assembly 100 is covered on the cavity 400, and is fixedly connected to the shell 200. The cavity 400 may also contain an electrolyte, and the battery cell 300 is immersed in the electrolyte.

[0050] As the outer protective layer of the single cell, the shell 200 has a certain structural strength and allows a certain amount of deformation to accommodate the expansion of the electrolyte in the shell 200 and the battery cell 300. For example, the shell 200 can be made of aluminum, and the shell 200 made of aluminum can accommodate the battery cell 300 and the electrolyte and can undergo a certain elastic deformation. Of course, the embodiment of the present application does not limit the shape and material of the shell 200.

[0051] The shape of the shell 200 can be adapted to the shape of the battery cell 300 to reduce the volume of the single battery. For example, the battery cell 300 is a rectangular parallelepiped structure as a whole, and the shell 200 is also a rectangular parallelepiped structure as a whole, and the length, width and thickness of the battery cell 300 correspond to the length, width and thickness of the shell 200 one by one.

[0052] refer to Figures 1 to 3 The top cover assembly 100 includes a top cover sheet 120 and a lower insulating member 130. The top cover sheet 120 is fixedly connected to the housing 200, and the lower insulating member 130 is connected to the side of the top cover sheet 120 facing the battery cell 300. The top cover sheet 120 can be made of a conductive material (such as aluminum), and the lower insulating member 130 can be made of an insulating material (such as plastic). The lower insulating member 130 is located on the side of the top cover sheet 120 facing the battery cell 300 to achieve insulation between the top cover sheet 120 and the battery cell 300.

[0053] In actual application, the outer periphery of the top cover sheet 120 is sealed and connected to the opening of the shell 200 to prevent the electrolyte in the cavity 400 from overflowing. For example, the shell 200 and the top cover sheet 120 are both made of aluminum, and the outer periphery of the top cover sheet 120 is welded and connected to the opening of the shell 200.

[0054] In addition, continue to refer to Figure 2 and Figure 3 The top cover sheet 120 may also be provided with a liquid injection port 150 and a pressure relief port 122. The liquid injection port 150 is used to add electrolyte into the cavity 400. The pressure relief port 122 is connected to an explosion-proof valve 140 for discharging high-temperature and high-pressure gas to the outside when the pressure in the cavity 400 exceeds a preset threshold.

[0055] refer to Figure 3The top cover assembly 100 also includes a pole 110, which includes a bottom plate 111 and a column 112 connected to the bottom plate 111, the bottom plate 111 is located in the cavity 400 and is electrically connected to the battery cell 300 (for example, the bottom plate 111 is welded to the pole ear of the battery cell 300), the column 112 is penetrated by the top cover sheet 120 and the lower insulating member 130, and a part of the structure of the column 112 is exposed from the side of the top cover sheet 120 away from the battery cell 300, so that the battery cell 300 is electrically connected to the external structure through the exposed column 112.

[0056] Specifically, continue to refer to Figure 3 , the top cover sheet 120 is provided with a first pole hole 121, the lower insulating member 130 is provided with a second pole hole 131, the first pole hole 121 and the second pole hole 131 are arranged opposite to each other, and a part of the structure of the column 112 is passed through the first pole hole 121 and the second pole hole 131, and is fixedly connected to the first pole hole 121 and / or the second pole hole 131. For example, a sealant is filled between the column 112 and the first pole hole 121 and the second pole hole 131, and the sealant, on the one hand, fixes the column 112 to the top cover sheet 120 and the lower insulating member 130, and on the other hand, seals the first pole hole 121 and the second pole hole 131.

[0057] Of course, if Figure 5 As shown, the column 112 can also be fixedly connected to the top cover sheet 120 by means of riveting. At this time, an upper insulating member 160 is provided between the column 112 and the riveting member.

[0058] In practical applications, the top cover assembly 100 may include one pole 110 or two poles 110. For example, when the top cover assembly 100 includes one pole 110, one of the pole tabs of the battery cell 300 is electrically connected to the pole 110, and the other pole tab of the battery cell 300 is electrically connected to the top cover sheet 120. Figure 2 As shown, when the top cover assembly 100 includes two poles 110, the two poles 110 include a positive pole 110a and a negative pole 110b, the positive pole 110a is electrically connected to the positive pole ear of the battery cell 300, and the negative pole 110b is electrically connected to the negative pole ear of the battery cell 300. The structures and sizes of the positive pole 110a and the negative pole 110b may be the same or different, and this is not limited in the embodiment of the present application.

[0059] like Figure 4As shown, the lower insulating member 130 includes a first surface 133 facing the battery cell 300, and the bottom plate 111 of the pole 110 contacts the first surface 133. When the pole 110 is subjected to a pulling force or a torsional force, since the bottom plate 111 of the pole 110 contacts the first surface 133, the force applied to the pole 110 is transmitted to the lower insulating member 130 through the bottom plate 111, which may easily cause deformation in the area where the lower insulating member 130 and the pole 110 are matched. When the deformation of the lower insulating member 130 is large, the lower insulating member 130 is prone to plastic deformation or even damage.

[0060] In view of this, if Figure 5 As shown, in the single battery provided by the embodiment of the present application, the first surface 133 of the lower insulating member 130 is provided with a reinforcing rib 132, and the reinforcing rib 132 is located on the peripheral side of the bottom plate 111. By providing the reinforcing rib 132 on the first surface 133, the structural strength of the lower insulating member 130 is increased, and when the lower insulating member 130 is subjected to the force transmitted from the pole 110, the lower insulating member 130 is not easily torsionally deformed or damaged.

[0061] The reinforcing rib 132 may be protrudingly disposed on the first surface 133 in a direction toward the battery cell 300. Exemplarily, the reinforcing rib 132 and the lower insulating member 130 may be an integrally formed structure. For example, when the reinforcing rib 132 and the lower insulating member 130 are both made of plastic, the reinforcing rib 132 and the lower insulating member 130 are integrally formed by an injection molding process.

[0062] The size of the reinforcing rib 132 is directly related to the structural strength of the lower insulating member 130. The larger the size of the reinforcing rib 132, the better the structural reinforcement effect on the lower insulating member 130, and the less likely the lower insulating member 130 is to be deformed or damaged. However, as the size of the reinforcing rib 132 increases, the weight of the lower insulating member 130 also increases, resulting in a decrease in the energy density of the single battery. Therefore, it is necessary to reasonably set the reinforcing rib 132 to increase the structural strength of the lower insulating member 130 while improving the energy density of the single battery.

[0063] In view of this, in the embodiment of the present application, the size of the reinforcing rib 132 is set according to the size of the bottom plate 111. Specifically, the orthographic projection area of ​​the bottom plate 111 on the first surface 133 is S1, and the orthographic projection area of ​​the reinforcing rib 132 on the first surface 133 is S2, wherein 0.02≤S2 / S1≤0.35. Optionally, 0.02≤S2 / S1≤0.15. Optionally, S2 / S1 can also be any value among 0.3, 0.2, 0.1, 0.08, 0.06, 0.05, 0.04, 0.03, 0.02, or a range of any two values.

[0064] Exemplarily, the area of ​​S1 is 1400 square millimeters to 26000 square millimeters, for example, any value among 1400 square millimeters, 3500 square millimeters, 5000 square millimeters, 7000 square millimeters, 10000 square millimeters, 15000 square millimeters, 20000 square millimeters, 22000 square millimeters, 25000 square millimeters, or any range consisting of any two of them.

[0065] Exemplarily, the area of ​​S2 is 250 square millimeters to 4100 square millimeters, for example, any value among 250 square millimeters, 300 square millimeters, 600 square millimeters, 1000 square millimeters, 1200 square millimeters, 1600 square millimeters, 2000 square millimeters, 2500 square millimeters, 3000 square millimeters, 3500 square millimeters, 4000 square millimeters, or a range of any two of them.

[0066] For example, when the orthographic projection of the bottom plate 111 on the first surface 133 is a rectangle, the length and width of the rectangle can be measured, and the projection area S1 of the bottom plate 111 is the product of the length and width of the rectangle. When the orthographic projection of the bottom plate 111 on the first surface 133 is an ellipse, the major axis and minor axis of the ellipse can be measured, and the projection area S1 of the bottom plate 111 can be obtained according to the lengths of the major axis and the minor axis. When the projection of the bottom plate 111 on the first surface 133 is an irregular shape, the bottom plate 111 can be photographed using a visual inspection system (CCD), and then the area S1 can be calculated using visual inspection software.

[0067] Similarly, when the orthographic projection of the reinforcing rib 132 on the first surface 133 is a rectangle, the length and width of the rectangle can be measured, and the projection area S2 of the reinforcing rib 132 is the product of the length and width of the rectangle. When the projection of the reinforcing rib 132 on the first surface 133 is an irregular shape, the reinforcing rib 132 can be photographed using a visual inspection system (CCD), and then the area S2 can be calculated using visual inspection software.

[0068] In some specific embodiments, when 0.02≤S2 / S1≤0.5 is satisfied, the weight of the lower insulating member 130 is made as small as possible while the structural strength of the lower insulating member 130 is increased, thereby improving the energy density of the single battery.

[0069] In some embodiments, the surface of the bottom plate 111 facing the battery cell 300 protrudes beyond the surface of the reinforcing rib 132 facing the battery cell 300, and the shortest distance from the surface of the bottom plate 111 facing the battery cell 300 to the surface of the reinforcing rib 132 facing the battery cell 300 is H, wherein 0.1 mm < H < 5 mm. Optionally, the value of H may also be any one of 0.2 mm, 0.8 mm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, 4.5 mm, or a range of any two of them.

[0070] It should be noted that when H satisfies the above range, welding of the tabs of the battery cell 300 and the bottom plate 111 is facilitated, the welding yield is improved and the difficulty of welding is reduced.

[0071] like Figure 8 As shown, in some embodiments, the reinforcing rib 132 includes a first side surface 1 and a second side surface 2 disposed opposite to each other, the first side surface 1 faces the second pole hole 131, and the second side surface 2 is away from the second pole hole 131, and the minimum distance between the first side surface 1 and the second side surface 2 is c, wherein 0.3 mm ≤ c ≤ 5 mm. For example, c is any value of 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, or a range of any two of them.

[0072] When c is less than 0.3 mm, it is difficult to process the reinforcing rib 132. For example, when the reinforcing rib 132 is formed by injection molding, due to the fluidity of liquid plastic, a smaller c of the reinforcing rib 132 may easily lead to insufficient injection molding.

[0073] When c is greater than 5 mm, the weight of the lower insulator 130 is large, which reduces the energy density of the single battery. In addition, when the reinforcing rib 132 is injection molded, c greater than 5 mm may easily cause the reinforcing rib 132 to shrink and deform.

[0074] like Fig.10 As shown, in some embodiments, the bottom plate 111 has an outer peripheral surface 3 facing the reinforcing rib 132, and the minimum distance from the first side surface 1 to the outer peripheral surface 3 is L, where 0 mm ≤ L ≤ 0.5 mm. For example, L is any value of 0 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, or a range of any two values. For example, the minimum distance between the portion of the outer peripheral surface 3 of the bottom plate 111 that is parallel to and opposite to the reinforcing rib 132 and the reinforcing rib 132 is L.

[0075] The distance between the first side surface 1 and the outer peripheral surface 3 of the bottom plate 111 is less than or equal to 0.5 mm, so that the distance between the bottom plate 111 and the reinforcing rib 132 is closer, so that the reinforcing rib 132 plays a limiting role to prevent the bottom plate 111 from rotating around the axis of the column 112.

[0076] When the distance between the first side surface 1 and the outer peripheral surface 3 of the bottom plate 111 is greater than 0 mm, a certain gap is provided between the bottom plate 111 and the reinforcing rib 132 to prevent interference during assembly due to processing errors of the reinforcing rib 132 and the bottom plate 111 .

[0077] like Figures 6 to 8As shown, in some embodiments, the first surface 133 is provided with a plurality of reinforcing ribs 132, and the plurality of reinforcing ribs 132 are arranged at intervals along the outer circumference of the bottom plate 111, so that the lower insulating member 130 can be reinforced along multiple areas of the outer circumference of the bottom plate 111. The structures and sizes of the plurality of reinforcing ribs 132 can be the same or different, and can be flexibly arranged according to actual needs.

[0078] When a plurality of reinforcing ribs 132 are disposed on the first surface 133 , an orthographic projection area S2 of the reinforcing ribs 132 on the first surface 133 is equal to a sum of orthographic projection areas of the reinforcing ribs 132 on the first surface 133 .

[0079] See also Figure 7 and Fig. 9 , the lower insulating member 130 has an intersecting first direction X and a second direction Y. In some embodiments, the bottom plate 111 has two first sides 111a extending along the first direction X and two second sides 111b extending along the second direction Y, the two first sides 111a are arranged oppositely in the second direction Y, the two second sides 111b are arranged oppositely in the first direction X, one first side 111a is connected to the two second sides 111b, and one second side 111b is connected to the two first sides 111a. For example, the orthographic projection of the bottom plate 111 on the first surface 133 is a rectangle, a missing-corner rectangle, a rounded rectangle, etc.

[0080] like Figure 7 As shown, reinforcing ribs 132 are provided at the corresponding positions of the two first sides 111a and the two second sides 111b, that is, reinforcing ribs 132 are provided at the outer sides of the two first sides 111a and the two second sides 111b, and the four reinforcing ribs 132 cooperate to limit the rotation of the bottom plate 111. And the plurality of reinforcing ribs 132 are arranged at intervals along the outer circumference of the bottom plate 111, so that the lower insulating member 130 can be reinforced in multiple areas along the outer circumference of the bottom plate 111.

[0081] Continue to refer Figure 8 In some embodiments, the reinforcing rib 132 disposed at the corresponding positions of the two second sides 111b has a first end 01 and a second end 02 that are opposite to each other along the second direction Y, and / or the reinforcing rib 132 disposed at the corresponding positions of the two first sides 111a has a first end 01 and a second end 02 that are opposite to each other along the first direction X, and the first end 01 and the second end 02 are provided with a rounded structure, and the radius of the rounded structure is R, wherein 0.2 mm ≤ R ≤ 2 mm. For example, R is any value of 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, or a range of any two of them.

[0082] When R is less than 0.2 mm, the two ends of the reinforcing rib 132 are too sharp. When the reinforcing rib 132 contacts the bottom plate 111 , the two ends of the reinforcing rib 132 are easy to scratch the bottom plate 111 to generate metal chips.

[0083] Compared with when R at both ends of the reinforcing rib 132 is smaller, when R is greater than 2 mm, the curvature at both ends of the reinforcing rib 132 is smaller, and the weight of the lower insulating member 130 is larger, which is not conducive to improving the weight energy density of the single battery.

[0084] Continue to refer Figure 8 In some embodiments, the reinforcing rib 132 corresponding to the first side 111a is a first reinforcing rib 132a, and the reinforcing rib 132 corresponding to the second side 111b is a second reinforcing rib 132b, the length of the first reinforcing rib 132a along the first direction X is b, the distance between the two first reinforcing ribs 132a is B, the length of the second reinforcing rib 132b along the second direction Y is a, and the distance between the two second reinforcing ribs 132b is A, wherein 0.2≤a / B≤1, and / or, 0.2≤b / A≤1. For example, a / B is any value of 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, or a range of any two values. For another example, b / A is any value of 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, or a range of any two values.

[0085] Exemplarily, a is 5 mm to 13 mm, for example, any value among 5 mm, 6 mm, 8 mm, 10 mm, 13 mm, or a range consisting of any two of them.

[0086] Exemplarily, b is 5 mm to 13 mm, for example, any value among 5 mm, 6 mm, 8 mm, 10 mm, 13 mm, or a range consisting of any two of them.

[0087] Exemplarily, A is 24 mm to 79 mm, for example, any value among 24 mm, 25 mm, 42 mm, 50 mm, 79 mm, or a range consisting of any two of them.

[0088] Exemplarily, B is 24 mm to 79 mm, for example, any value among 24 mm, 25 mm, 42 mm, 50 mm, 79 mm, or a range consisting of any two of them.

[0089] It should be noted that when the value of a / B or b / A is less than 0.2, the size of the reinforcing rib 132 is small, the structural reinforcement effect on the lower insulating member 130 is weak, and the lower insulating member 130 is easily deformed and damaged.

[0090] It should be noted that when the value of a / B or b / A is greater than 1, the size of the reinforcing rib 132 is larger and the weight of the lower insulating member 130 is larger, which is not conducive to improving the weight energy density of the single battery.

[0091] When the top cover assembly 100 includes one pole 110, a reinforcing rib 132 is provided corresponding to the pole 110; when the top cover assembly 100 includes two poles 110, a reinforcing rib 132 may be provided corresponding to one of the poles 110, or a reinforcing rib 132 may be provided corresponding to each pole 110. For example, the pole 110 includes a positive pole 110a and a negative pole 110b, and the first surface 133 may be provided with a reinforcing rib 132 only corresponding to the positive pole 110a, or the first surface 133 may be provided with a reinforcing rib 132 only corresponding to the negative pole 110b, or the first surface 133 may be provided with a reinforcing rib 132 corresponding to the positive pole 110a, and a reinforcing rib 132 may also be provided corresponding to the negative pole 110b.

[0092] In order to further illustrate that the technical solution provided by the present application achieves better beneficial effects, please refer to Table 1 below, which provides examples 1-22 and comparative examples 1-2 for illustration. Only when the torque value of the pole 110 meets the requirements and the weight energy density of the single cell meets the requirements is it judged to be qualified.

[0093] 1. The test method for the torque value of the pole 110 is as follows: when the torque value satisfies ≥10N.m, it is determined to meet the requirements; otherwise, it is determined to fail to meet the requirements:

[0094] 1) Weld a square metal block on the top of the pole 110;

[0095] 2) Fix the top cover sheet 120 around;

[0096] 3) Use a torque wrench to hold the metal block on the top of the pole 110 ; twist it in one direction until the pole 110 fails to rotate, and read the maximum value on the torque wrench, which is the torque value of the pole 110 .

[0097] 2. The calculation method of the weight energy density of a single battery is as follows: when the weight energy density meets ≥140wh / kg, it is considered qualified, otherwise it is considered unqualified:

[0098] Battery weight energy density = battery capacity × discharge platform / weight. These three indicators will be marked on the outer shell of the single battery when it leaves the factory and can be read directly.

[0099]

[0100]

[0101] Table 1

[0102] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A single cell battery, characterized in that: The invention comprises a shell (200), a top cover assembly (100) and a battery cell (300), wherein the shell (200) is provided with a cavity (400), the battery cell (300) is located in the cavity (400), and the top cover assembly (100) is covered in the cavity (400) and fixedly connected to the shell (200); The top cover assembly (100) comprises a top cover sheet (120), a lower insulating member (130) and a pole (110); the top cover sheet (120) is fixedly connected to the housing (200); the top cover sheet (120) is provided with a first pole hole (121); the lower insulating member (130) is provided with a second pole hole (131); the lower insulating member (130) has a first surface (133) facing the battery cell (300); and the lower insulating member (130) is connected to a side of the top cover sheet (120) facing the battery cell (300); The pole (110) comprises a bottom plate (111) and a column (112) connected to the bottom plate (111); the bottom plate (111) is located in the cavity (400) and is used to be electrically connected to the battery cell (300); the column (112) is inserted into the first pole hole (121) and the second pole hole (131); the bottom plate (111) is located on a side of the lower insulating member (130) facing the battery cell (300) and is in contact with the first surface (133); The first surface (133) is provided with a reinforcing rib (132), and the reinforcing rib (132) is located on the peripheral side of the bottom plate (111), the orthographic projection area of ​​the bottom plate (111) on the first surface (133) is S1, and the orthographic projection area of ​​the reinforcing rib (132) on the first surface (133) is S2, wherein 0.02≤S2 / S1≤0.

35.

2. The single cell according to claim 1, characterized in that: 0.02≤S2 / S1≤0.

15.

3. The single cell according to claim 1, characterized in that: The reinforcing rib (132) comprises a first side surface (1) and a second side surface (2) arranged opposite to each other, the first side surface (1) faces the second pole hole (131), the second side surface (2) is away from the second pole hole (131), and the minimum distance between the first side surface (1) and the second side surface (2) is c, wherein 0.3 mm ≤ c ≤ 5 mm.

4. The single cell according to claim 2, characterized in that: The reinforcing rib (132) comprises a first side surface (1) and a second side surface (2) arranged opposite to each other, the first side surface (1) faces the second pole hole (131), the bottom plate (111) has an outer peripheral surface (3) facing the reinforcing rib (132), and the minimum distance from the first side surface (1) to the outer peripheral surface (3) is L, wherein 0 mm ≤ L ≤ 0.5 mm.

5. The single cell according to any one of claims 1 to 4, characterized in that: The first surface (133) is provided with a plurality of reinforcing ribs (132), and the plurality of reinforcing ribs (132) are arranged at intervals along the outer peripheral side of the bottom plate (111).

6. The single cell according to claim 5, characterized in that: The lower insulating member (130) has a first direction (X) and a second direction (Y) intersecting each other; the bottom plate (111) has two first sides (111a) extending along the first direction (X) and two second sides (111b) extending along the second direction (Y); the two first sides (111a) are arranged opposite to each other in the second direction (Y); the two second sides (111b) are arranged opposite to each other in the first direction (X); one first side (111a) is connected to two second sides (111b); one second side (111b) is connected to two first sides (111a); and the reinforcing ribs (132) are arranged on the outer sides of the two first sides (111a) and the two second sides (111b).

7. The single cell according to claim 6, characterized in that: The reinforcing rib (132) corresponding to the first side (111a) is a first reinforcing rib (132a), and the reinforcing rib (132) corresponding to the second side (111b) is a second reinforcing rib (132b). The length of the first reinforcing rib (132a) along the first direction (X) is b, and the distance between the two first reinforcing ribs (132a) is B. The length of the second reinforcing rib (132b) along the second direction (Y) is a, and the distance between the two second reinforcing ribs (132b) is A. Among them, 0.2≤a / B≤1, and / or, 0.2≤b / A≤1.

8. The single cell according to claim 7, characterized in that: The reinforcing rib (132) arranged at the corresponding positions of the two second sides (111b) has a first end (01) and a second end (02) opposite to each other along the second direction (Y), and / or the reinforcing rib (132) arranged at the corresponding positions of the two first sides (111a) has a first end (01) and a second end (02) opposite to each other along the first direction (X), and the first end (01) and the second end (02) are provided with a chamfered structure.

9. The single cell according to claim 1, characterized in that: The surface of the bottom plate (111) facing the battery cell (300) protrudes beyond the surface of the reinforcing rib (132) facing the battery cell (300), and the shortest distance from the surface of the bottom plate (111) facing the battery cell (300) to the surface of the reinforcing rib (132) facing the battery cell (300) is H, wherein 0.1 mm < H < 5 mm.

10. The single cell according to claim 1, characterized in that: The pole (110) comprises a positive pole (110a) and a negative pole (110b); the first surface (133) is provided with a reinforcing rib (132) at a position corresponding to the positive pole (110a); the reinforcing rib (132) is provided on the circumference of the positive pole (110a); and the first surface (133) is also provided with a reinforcing rib (132) at a position corresponding to the negative pole (110b); the reinforcing rib (132) is provided on the circumference of the negative pole (110b).

11. A battery pack, characterized in that: The invention comprises the single cell according to any one of claims 1 to 10.

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