Battery cell, battery pack, and electric device

Abstract

A battery cell, a battery pack, and an electric device. The battery cell comprises: a casing (1) internally provided with an accommodating cavity having an opening; a cell body arranged in the accommodating cavity; and a top cover assembly (11) connected to the opening side of the casing (1) and covering the opening; wherein the top cover assembly (11) comprises a top cover (111) and poles (112), the top cover (111) has a first direction (X), the top cover (111) is provided with pole holes (1111) extending in the first direction (X), and the poles (112) are embedded in the pole holes (1111); the top cover (111) is provided with protruding structures (1112) on the sides of the peripheries of the pole holes (1111) away from the casing, and the protruding structures (1112) are used for limiting the positions of the poles (112); the cross-sectional area of each pole hole (1111) perpendicular to the first direction (X) is s1, the cross-sectional area of the top cover (111) perpendicular to the first direction (X) is s2, and the ratio of s1 to s2 satisfies: 0.015<s1 / s2<0.15. In this way, by providing the protruding structures (1112) and limiting the numerical range of s1 / s2, the overall strength of the top cover assembly (11) can be improved, thereby improving the safety performance of the battery cell.

Description

Single cell, battery pack and electrical equipment

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on February 28, 2024, with application number 202420378895.1 and application name “A single cell battery, a battery pack and an electrical device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of battery technology, and specifically relates to a single cell, a battery pack, and an electrical device. Background Art

[0003] Cells are the storage units of power batteries and determine the range of new energy vehicles. As the demand for range continues to increase, the current output capacity of cells is becoming increasingly important. The top cover assembly is a key component of a cell, typically consisting of a top cover with a terminal hole, into which a terminal is installed. The terminal determines the current output capacity of the cell.

[0004] Single battery cells typically increase their terminal dimensions to increase their current-carrying area, thereby improving their current output capacity. However, as the terminal size increases, the terminal hole also needs to be enlarged. This can reduce the overall strength of the top cover assembly, causing deformation and compromising the safety of the single battery cell.

[0005] Application Contents

[0006] The present application aims to provide a single cell battery, a battery pack and an electrical device to solve the problem that the top cover assembly of the existing single cell battery has low overall strength and the top cover is easy to deform, resulting in reduced safety performance of the single cell battery.

[0007] In order to solve the above technical problems, this application is implemented as follows:

[0008] In a first aspect, the present application discloses a single cell battery, comprising:

[0009] A housing having an opening disposed therein;

[0010] A battery cell body, the battery cell body being disposed in the accommodating cavity;

[0011] and a top cover assembly, the top cover assembly being connected to the opening side of the shell and covering the opening; the top cover assembly comprising a top cover and a pole, the top cover having a first direction, a pole hole extending along the first direction being provided on the top cover, the pole being embedded in the pole hole; the top cover having a protrusion structure on a side of the outer periphery of the pole hole away from the shell, the protrusion structure being used to limit the pole;

[0012] The cross-sectional area of ​​the pole hole perpendicular to the first direction is s1, the cross-sectional area of ​​the top cover perpendicular to the first direction is s2, and the ratio of s1 to s2 satisfies: 0.015 <s1 / s2<0.15。

[0013] Optionally, the range of s1 is 50mm 2 ≤s1≤5000mm 2 .

[0014] Optionally, the range of s2 is 1000mm 2 ≤s2≤65000mm 2 .

[0015] Optionally, the protruding structure includes a peripheral side wall and a top wall;

[0016] One end of the peripheral side wall is connected to the top cover, the other end of the peripheral side wall extends in a direction away from the top cover, the top wall is connected to the other end of the peripheral side wall, and the top wall, the peripheral side wall and the top cover enclose a receiving space for limiting the pole.

[0017] Optionally, the pole is provided with a boss along the circumferential direction, and the boss is embedded between the top wall and the top cover to limit the pole from escaping from the accommodating space.

[0018] Optionally, the boss is a full circle of protrusions arranged along the circumference of the pole; or, the boss is a plurality of local protrusions arranged at intervals along the circumference of the pole.

[0019] Optionally, the top cover further has a second direction and a third direction, the second direction and the third direction are perpendicular to the first direction; the width of the top cover along the second direction is f, the length of the top cover along the third direction is e, and the ratio of f to e satisfies: 0.15 <f / e<1。

[0020] Optionally, the range of f satisfies, 10mm <f<100mm。

[0021] Optionally, the range of f satisfies, 10mm <f<85mm。

[0022] Optionally, the range of e satisfies 100mm <e<650mm。

[0023] Optionally, the range of e satisfies 120mm <e<400mm。

[0024] Optionally, the thickness of the top cover along the first direction is g, which satisfies: 1 mm <g<3.5mm。

[0025] Optionally, the minimum distance between the edge of the pole hole and the edge of the top cover is a, satisfying: a>3.5mm.

[0026] Optionally, along the first direction, the pole has a welding end surface facing away from the top cover, and the welding end surface is used for welding to an external current collecting device;

[0027] The orthographic projection of the welding end surface along the first direction is the first projection surface, and the maximum outer dimension of the first projection surface is c, which satisfies: 5mm <c<40mm。

[0028] Optionally, the top cover assembly further comprises a plastic part, which is connected to a side of the protruding structure away from the shell, and at least a portion of the plastic part extends between the protruding structure and the pole to connect the protruding structure and the pole.

[0029] Optionally, the top cover assembly further includes a sealing ring, which is sleeved outside the pole and abuts against the top cover.

[0030] Optionally, the sealing ring includes at least one of a plastic sealing ring or a foam sealing ring.

[0031] Optionally, the thickness of the pole hole along the first direction is d, and d satisfies: 3.7 mm <d<8mm。

[0032] In a second aspect, the present application further discloses a battery pack, which includes: a single cell battery as described in any one of the above items.

[0033] In a third aspect, the present application further discloses an electrical device, which includes the battery pack.

[0034] In the embodiment of the present application, since the single cell includes: a housing, an accommodating cavity with an opening is arranged inside the housing; a battery cell body, the battery cell body is arranged in the accommodating cavity; and a top cover assembly, the top cover assembly is connected to the opening side of the housing and seals the opening; the top cover assembly includes a top cover and a pole post, the top cover has a first direction, a pole post hole extending along the first direction is arranged on the top cover, and the pole post is embedded in the pole post hole; a convex structure is arranged on the outer periphery of the pole post hole on the side of the top cover away from the housing, and the convex structure is used for limiting the pole post; wherein, the cross-sectional area of the pole post hole perpendicular to the first direction is s 1, the cross-sectional area of the top cover perpendicular to the first direction is s2, and the ratio of s1 to s2 satisfies: 0.015 < s1 / s2 < 0.15. In this way, on the one hand, since a convex structure is arranged on the outer periphery of the pole post hole, not only can the pole post be limited, but also the mechanical strength at the pole post hole can be increased, effectively avoiding deformation of the top cover. On the other hand, since the ratio of the cross-sectional area s1 of the pole post hole perpendicular to the first direction to the cross-sectional area s2 of the top cover perpendicular to the first direction satisfies 0.015 < s1 / s2 < 0.15, within this numerical range, when the external dimension of the pole post is adaptively increased, the influence of the corresponding pole post hole on the strength of the top cover is relatively small, so that the current output capacity of the single cell can be improved, and at the same time the overall strength of the top cover assembly can be improved, thereby improving the safety performance of the single cell.

[0035] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present application.

[0036] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically exemplified below. Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts. [[ID=!15]]

[0038] Figure 1 is a schematic structural diagram of a single cell provided by an embodiment of the present application;

[0039] Figure 2 is one of the schematic structural diagrams of the top cover assembly in the single cell provided by the embodiment of the present application; [[ID=!@20]] It should be noted that there seems to be an incorrect tag format in item ID 15 and ID 20 in the original content. I have translated them as they are while pointing out this potential issue. If this is a specific format requirement that needs to be corrected, please provide more context or clarify the correct format.

[0040] FIG3 is a second structural diagram of a top cover assembly in a single cell provided in an embodiment of the present application;

[0041] FIG4 is a third structural schematic diagram of a top cover assembly in a single cell provided in an embodiment of the present application;

[0042] FIG5 is a fourth structural diagram of a top cover assembly in a single cell provided in an embodiment of the present application;

[0043] FIG6 is a fifth structural diagram of a top cover assembly in a single cell provided in an embodiment of the present application;

[0044] FIG7 is a schematic structural diagram of a top cover before assembly provided by an embodiment of the present application;

[0045] FIG8 is a partial enlarged view of position A in FIG7;

[0046] FIG9 is a schematic structural diagram of an assembled top cover according to an embodiment of the present application;

[0047] FIG10 is a partial enlarged view of position B in FIG9;

[0048] FIG11 is a schematic structural diagram of a pole provided in an embodiment of the present application.

[0049] Figure numerals: 1. Shell, 11. Top cover assembly, 111. Top cover, 1111. Pole hole, 1112. Protruding structure, 11121. Side wall, 11122. Top wall, 1113. Accommodating space, 112. Pole, 1121. Boss, 1122. Welding end face, 113. Plastic part, 114. Sealing ring, X. First direction, Y. Second direction, Z. Third direction. Specific embodiments

[0050] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0051] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly refer to one or more of the features. Throughout the description of this application, unless otherwise specified, "plurality" means two or more. Furthermore, "and / or" in the specification and claims refers to at least one of the connected entities, and the character " / " generally indicates an "or" relationship between the connected entities.

[0052] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0053] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0054] An embodiment of the present application provides a single cell battery, which will be described in detail below with reference to the accompanying drawings.

[0055] Referring to Figure 1, a structural schematic diagram of a single cell provided in an embodiment of the present application is shown; referring to Figures 2 to 6, a structural schematic diagram of a top cover assembly in a single cell provided in an embodiment of the present application is shown; referring to Figure 7, a structural schematic diagram of a top cover before assembly provided in an embodiment of the present application is shown; referring to Figure 8, a partial enlarged view of position A in Figure 7 is shown; referring to Figure 9, a structural schematic diagram of a top cover after assembly provided in an embodiment of the present application is shown; referring to Figure 10, a partial enlarged view of position B in Figure 9 is shown; referring to Figure 11, a structural schematic diagram of a pole provided in an embodiment of the present application is shown.

[0056] As shown in Figure 1, the present application provides a single cell, comprising: a housing 1, within which there is provided a receiving cavity with an opening; a cell body disposed within the receiving cavity; and a top cover assembly 11 connected to the opening side of the housing 1 to seal the opening. As shown in Figures 2 to 6, the top cover assembly 11 includes a top cover 111 and a pole post 112. The top cover 111 has a first direction X, and a pole post hole 1111 extending along the first direction X is provided on the top cover 111. The pole post 112 is embedded in the pole post hole 1111. The top cover 111 is provided with a raised structure 1112 on the side away from the housing 1 on the outer periphery of the pole post hole 1111, and the raised structure 1112 is used to limit the pole post 112. Among them, the cross-sectional area s1 of the pole post hole 1111 perpendicular to the first direction X and the cross-sectional area s2 of the top cover 111 perpendicular to the first direction X satisfy: 0.015 < s1 / s2 < 0.15.

[0057] In an embodiment of the present application, on the one hand, since the raised structure 1112 is provided on the outer periphery of the pole post hole 1111, it can not only limit the pole post 112, but also increase the mechanical strength at the pole post hole 1111, effectively avoiding deformation of the top cover 111. On the other hand, since the ratio of the cross-sectional area s1 of the pole post hole 1111 perpendicular to the first direction X to the cross-sectional area s2 of the top cover 111 perpendicular to the first direction X satisfies 0.015 < s1 / s2 < 0.15, within this numerical range, when the outer dimension of the pole post 112 is increased adaptively, the influence of the corresponding pole post hole 1111 on the strength of the top cover 111 is relatively small, thereby improving the current output capacity of the single cell, and at the same time improving the overall strength of the top cover assembly 11, and further improving the safety performance of the single cell.

[0058] It should be noted that, as shown in Figure 1, the first direction X in the embodiment of the present application refers to the thickness direction of the top cover 111, that is, the height direction of the single cell, the second direction Y refers to the width direction of the top cover 111, that is, the width direction of the single cell, and the third direction Z refers to the length direction of the top cover 111, that is, the length direction of the single cell. In addition, in the embodiment of the present application, the cross-sectional area s1 of the top cover 111 perpendicular to the first direction X does not deduct the area of other openings such as the pole post hole. Taking a rectangular top cover as an example, the cross-sectional area of the top cover 111 perpendicular to the first direction X is equal to the product of the length and width of the top cover 111. In the embodiment of the present application, the cross-sectional area s1 of the pole post hole 1111 perpendicular to the first direction X is the area enclosed by the projection of the hole wall of the pole post hole 1111.

[0059] In actual applications, the pole hole 1111 can be rectangular, circular, elliptical or other regular shapes. The embodiment of the present application does not limit the shape of the pole hole 1111, and those skilled in the art can adjust it according to actual needs. It can be understood that the cross-sectional shape of the pole 112 perpendicular to the first direction X is compatible with the shape of the pole hole 1111, so that the pole 112 can be assembled into the pole hole 1111. In addition, the embodiment of the present application does not limit the specific values ​​of the cross-sectional area s1 of the pole hole 1111 perpendicular to the first direction X and the cross-sectional area s2 of the top cover 111 perpendicular to the first direction X. Those skilled in the art can adjust it based on the ratio range of the two according to actual needs. In specific applications, taking into account the performance and manufacturing cost of the top cover assembly 11, the cross-sectional area s1 of the pole hole 1111 perpendicular to the first direction X is generally 50mm. 2 ≤s1≤5000mm 2 Correspondingly, the cross-sectional area s2 of the top cover 111 perpendicular to the first direction X is generally 1000 mm 2 ≤s2≤65000mm 2 .

[0060] In some optional embodiments of the present application, the top cover assembly 11 further includes a plastic part 113, which is connected to a side of the protruding structure 1112 away from the shell 1, and at least a portion of the plastic part 113 extends between the protruding structure 1112 and the pole 112 to connect the protruding structure 1112 and the pole 112.

[0061] In the embodiment of the present application, since the plastic part 113 is provided, and at least a portion of the plastic part 113 extends between the protruding structure 1112 and the pole 112, on the one hand, a reliable connection between the pole 112 and the protruding structure 1112 can be achieved; on the other hand, the pole 112 and the protruding structure 1112 can be insulated, avoiding the problem of causing a battery short circuit.

[0062] It should be noted that the plastic part 113 is formed by injection molding. In practical applications, the terminal 112 is typically first assembled to the top cover 111; the assembled terminal 112 and top cover 111 are then placed into an injection mold; and finally, plastic material is injected into the injection mold to form the plastic part 113 located between the protrusion 1112 and the terminal 112. During the welding process between the terminal 112 and an external busbar, such as a busbar, the high welding temperature may cause the plastic part 113 to melt, which can degrade the connection and insulation properties of the plastic part 113, thereby reducing the safety of the battery cell.

[0063] In some optional embodiments of the present application, the top cover assembly 11 further includes a sealing ring 114. The sealing ring 114 is sleeved outside the pole column 112 and abuts against the top cover 111 to achieve a sealed connection between the pole column 112 and the top cover 111, so as to prevent external impurities such as water and dust from entering the housing 1 through the gap between the pole column 112 and the top cover 111, thereby improving the safety of the battery cell body in the housing 1.

[0064] It should be noted that the sealing ring 114 may include at least one of a plastic sealing ring or a foam sealing ring. The embodiments of the present application do not specifically limit the material of the sealing ring 114.

[0065] The following are examples and comparative examples where the ratio range of the cross-sectional area s1 of the pole hole 1111 perpendicular to the first direction X to the cross-sectional area s2 of the top cover 111 perpendicular to the first direction X is 0.015 < s1 / s2 < 0.15, as well as the characterization of the test results.

[0066] Among them, the test method for the compressive strength of the top cover 111 is: fix the top cover assembly 11 on a tensile testing machine, apply a thrust to the pole column 112 using a push head until the top cover 111 is deformed, and record the magnitude of the thrust when the top cover 111 is deformed.

[0067] The calculation method of the melting rate of the plastic is to batch select some single cells, such as 300 single cells, with the same other conditions, change the ratio of s1 / s2 by adjusting s1 and s2, observe the number of plastic parts 113 that melt during the welding process, divide by the total number, and obtain the melting rate.

[0068] Table 1

[0069] Referring to Table 1, the ratios of the cross-sectional area s1 of the pole hole 1111 perpendicular to the first direction X to the cross-sectional area s2 of the top cover 111 perpendicular to the first direction X being 0.025, 0.05, 0.075, 0.100, 0.144, 0.017, 0.033, 0.050, 0.067, 0.100, and 0.133 are taken as examples, and the ratios of the cross-sectional area s1 of the pole hole 1111 perpendicular to the first direction X to the cross-sectional area s2 of the top cover 111 perpendicular to the first direction X being 0.013, 0.015, 0.200, 0.008, 0.15, and 0.167 are taken as comparative examples.

[0070] As can be seen from Table 1, when s1 / s2 ≤ 0.015, due to the excessively small cross-sectional area of the pole hole 1111, it is easy to cause the plastic part 113 to melt during the welding of the pole column 112 and the external busbar device. At this time, the melting rate of the plastic part 113 is greater than or equal to 85%, and the melting rate of the plastic part is too high.

[0071] As can be seen from Table 1, when 0.15 ≤ s1 / s2, due to the excessively large cross-sectional area of the pole hole 1111, when the top cover 111 and the housing 1 are welded, it is easy to cause the plastic part 113 to melt, resulting in a melting rate of the plastic part 113 greater than or equal to 96%. The melting rate of the plastic part 113 is too high, and due to the excessive proportion of the cross-sectional area of the pole hole 1111, the strength of the top cover 111 is affected, and the compressive strength of the top cover 111 is less than or equal to 900N, and the compressive strength of the top cover 111 is insufficient.

[0072] When the ratio range of s1 / s2 is 0.015 < s1 / s2 < 0.15, the top cover 111 can have sufficient structural strength, and the melting rate of the plastic part 113 is relatively low, which is beneficial to improving the structural strength and use safety of the single battery.

[0073] In some optional embodiments of the present application, the convex structure 1112 includes a circumferential side wall 11121 and a top wall 11122; one end of the circumferential side wall 11121 is connected to the top cover 111, the other end of the circumferential side wall 11121 extends in a direction away from the top cover 111, and the top wall 11122 is connected to the other end of the circumferential side wall 11121. The top wall 11122, the circumferential side wall 11121 and the top cover 111 enclose a receiving space 1113 for limiting the pole 112.

[0074] In practical applications, in order to facilitate the processing and assembly of the top cover assembly 11, the staff usually first processes the convex structure 1112 shown in FIGS. 7 to 8 around the pole hole 1111, that is, the state where both the circumferential side wall 11121 and the top wall 11122 are perpendicular to the top cover 111; then the pole 112 and the top cover 111 are assembled; finally, the convex structure 1112 is riveted to form the convex structure 1112 shown in FIGS. 9 to 10, that is, the top wall 11122 is bent relative to the circumferential side wall 11121, so that the pole 112 is restricted in the receiving space 1113 formed by the top wall 11122, the circumferential side wall 11121 and the top cover 111 for limiting the pole 112. This convex structure 1112 has a simple structure, is easy to process and assemble, is beneficial to reducing the processing cost of the top cover assembly 11, and improving the assembly efficiency of the top cover assembly 11.

[0075] As shown in FIG. 11, the pole 112 is provided with a boss 1121 along the circumferential direction, and the boss 1121 is embedded between the top wall 11122 and the top cover 111 to prevent the pole 112 from detaching from the receiving space 1113.

[0076] In the embodiment of the present application, due to the provision of the boss 1121, and the boss 1121 is embedded between the top wall 11122 and the top cover 111, in this way, the pole 112 can be restricted from detaching from the receiving space 1113, and the connection reliability between the pole 112 and the top cover 111 is improved.

[0077] It should be noted that the boss 1121 in the embodiments of the present application can be a complete circle of protrusions arranged circumferentially along the pole 112, or can be multiple local protrusions arranged at intervals circumferentially along the pole 112. The embodiments of the present application do not limit the specific structure of the boss 1121, and those skilled in the art can adjust it according to actual needs.

[0078] As shown in FIG. 4, the top cover 111 also has a second direction Y and a third direction Z, and the second direction Y, the third direction Z and the first direction X are perpendicular to each other in pairs; the width of the top cover 111 along the second direction Y is f, and the length of the top cover 111 along the third direction Z is e. The ratio of f to e satisfies: 0.15 < f / e < 1. Since the greater the length e of the top cover 111 along the third direction Z, that is, the longer the top cover 111, the greater the battery capacity of the single cell, but the more likely the top cover 111 is to be deformed, resulting in a reduction in the structural strength of the top cover 111. And when the length e of the top cover 111 along the third direction Z is smaller, that is, the shorter the top cover 111, although the structural strength of the top cover 111 is increased, the battery capacity of the single cell is limited, and the design and processing difficulty of the top cover 111 is increased. Therefore, through testing, when the ratio of the width f of the top cover 111 along the second direction Y to the length e of the top cover 111 along the third direction Z satisfies 0.15 < f / e < 1, the top cover 111 has sufficient structural strength, and at the same time, the battery capacity of the single cell is also increased.

[0079] It should be noted that the embodiments of the present application do not limit the specific values of the width f of the top cover 111 along the second direction Y and the length e of the top cover 111 along the third direction Z, and those skilled in the art can adjust them based on the ratio range of the two according to actual needs. In specific applications, considering the service performance and manufacturing cost of the top cover assembly 11 comprehensively, the width f of the top cover 111 along the second direction Y is generally 10 mm < f < 100 mm, preferably 10 mm < f < 85 mm; correspondingly, the length e of the top cover 111 along the third direction Z is generally 100 mm < e < 650 mm, preferably 120 mm < e < 400 mm.

[0080] The following are embodiments in which the ratio range of the width f of the top cover 111 along the second direction Y to the length e of the top cover 111 along the third direction Z is 0.15 < f / e < 1, and the test effect characterization.

[0081] Table 2

[0082] Referring to Table 2, when the ratio range of the width f of the top cover 111 along the second direction Y to the length e of the top cover 111 along the third direction Z is 0.15 < f / e < 1, it can make the top cover 111 have sufficient structural strength, and at the same time, the battery capacity of the single cell is also increased, which is beneficial to improving the structural strength and battery capacity of the single cell.

[0083] When f / e = 1, although the top cover 111 has sufficient strength, at this time, the top cover 111 is a square structure, which is not conducive to the utilization of the internal space of the single cell, and the volume energy density of the single cell is reduced.

[0084] Therefore, when the ratio range of f / e is 0.15 < f / e < 1, it can not only ensure the strength of the top cover 111, but also the single cell has a high volume energy density.

[0085] As shown in FIG. 6, the thickness of the top cover 111 in the first direction X is g, satisfying: 1 mm < g < 3.5 mm. Since the greater the thickness g of the top cover 111 in the first direction X, that is, the thicker the top cover 111, the stronger the structural strength of the top cover 111 can be. However, at the same time, the manufacturing cost of the top cover assembly 11 is increased. Therefore, through testing, when the thickness g of the top cover 111 in the first direction X satisfies 1 mm < g < 3.5 mm, the top cover 111 has sufficient structural strength, and raw materials can be saved, which is beneficial to reducing the manufacturing cost of the top cover 111.

[0086] The following are embodiments in which the numerical range of the thickness g of the top cover 111 in the first direction X is 1 mm < g < 3.5 mm, and the test effect characterization.

[0087] Table 3

[0088] Therefore, when the numerical range of g is 1 mm < g < 3.5 mm, the top cover 111 can have sufficient structural strength, the compressive strength of the top cover 111 is greater than 500 N, and raw materials are saved, which is beneficial to reducing the manufacturing cost of the top cover 111.

[0089] When g ≥ 3.5 mm, the thickness of the top cover 111 is too large, the weight of the single cell increases, and the manufacturing cost of the single cell increases.

[0090] As shown in FIG. 5, the minimum distance between the edge of the pole hole 1111 and the edge of the top cover 111 is a, satisfying: a > 3.5 mm. In this way, the melting rate of the plastic part 113 located between the pole 112 and the convex structure 1112 during the welding process of the pole 112 can be effectively reduced, thereby improving the connection performance and insulation performance of the plastic part 113, which is beneficial to improving the use safety of the single cell.

[0091] The following are embodiments in which the minimum distance a between the edge of the pole hole 1111 and the edge of the top cover 111 has a numerical range of a > 3.5 mm, and the test effect characterization.

[0092] Table 4

[0093] Referring to Table 4, the numerical values of the minimum distance a between the edge of the terminal post hole 1111 and the edge of the top cover 111 being 3.5 mm, 5 mm, 10 mm, and 15 mm are taken as examples, and the numerical value of the minimum distance a between the edge of the terminal post hole 1111 and the edge of the top cover 111 being 3 mm is taken as a comparative example.

[0094] It can be obtained from Table 4 that when a is 3 mm, the compressive strength of the top cover 111 is 700 N, and the melting rate of the plastic part 113 is 95%, that is, the structural strength of the top cover 111 is relatively low and the melting rate during the welding process of the terminal post 112 is relatively high. When a is 3.5 mm, the compressive strength of the top cover 111 is 974 N, and the melting rate of the plastic part 113 is 82%, that is, the structural strength of the top cover 111 is relatively low and the melting rate during the welding process of the terminal post 112 is relatively high. When a is 5 mm, the compressive strength of the top cover 111 is 1370 N, and the melting rate of the plastic part 113 is 20%, that is, the structural strength of the top cover 111 is greatly improved, and the melting rate during the welding process of the terminal post 112 is greatly reduced. When a is 10 mm, the compressive strength of the top cover 111 is 1630 N, and the melting rate of the plastic part 113 is 0%, that is, the structural strength of the top cover 111 continues to increase, and no melting phenomenon occurs during the welding process of the terminal post 112. When a is 15 mm, the compressive strength of the top cover 111 is 2100 N, and the melting rate of the plastic part 113 is 45%, that is, the structural strength of the top cover 111 is somewhat improved, but the melting rate during the welding process of the terminal post 112 is somewhat increased.

[0095] In some embodiments, a ≤ 40 mm. Limited by the size of the top cover 111, if a is too large, the terminal post hole 1111 will be too small, which will cause the terminal post 112 to be too small and unable to meet the overcurrent requirement.

[0096] As shown in FIG. 11, along the first direction X, the terminal post 112 has a welding end face 1122 facing away from the top cover 111, and the welding end face 1122 is used for welding with an external busbar device; the positive projection of the welding end face 1122 along the first direction X is a first projection plane, and the maximum outer dimension of the first projection plane is c, satisfying: 5 mm < c < 40 mm. Generally, when the maximum outer dimension c of the first projection plane is larger, the area of the welding end face 1122 is larger, which can improve the reliability of current transmission. However, at the same time, it will cause the size of the terminal post hole 1111 to increase, resulting in a reduction in the overall strength of the top cover 111. When the maximum outer dimension c of the first projection plane is smaller, the area of the welding end face 1122 is smaller, and it is easy to cause the terminal post 112 to be unable to be welded with the external busbar device during the welding process, affecting the transmission of current; or causing the plastic part 113 to melt, affecting the use safety of the single cell. Therefore, through testing, when the maximum outer dimension c of the first projection plane satisfies 5 mm < c < 40 mm, the top cover 111 has sufficient strength. At the same time, it can improve the welding strength between the terminal post 112 and the external busbar device, which is beneficial to improving the reliability of current transmission.

[0097] It should be noted that the maximum outer dimension in the embodiments of this application refers to the maximum value of the outer dimensions on the first projection plane. Specifically, taking the first projection plane as a rectangle as an example, the maximum outer dimension is the diagonal length of the rectangle; taking the first projection plane as a circle as an example, the maximum outer dimension is the diameter of the circle; taking the first projection plane as an ellipse as an example, the maximum outer dimension is the major axis length of the ellipse, and so on. Examples are not given one by one here.

[0098] The following are embodiments where the numerical range of the maximum outer dimension c of the first projection plane is 5 mm < c < 40 mm, as well as the characterization of test effects.

[0099] Table 5

[0100] Referring to Table 5, when the numerical range of c is 5 mm < c < 40 mm, the top cover 111 has sufficient compressive strength, and at the same time, the welding strength between the pole column 112 and the external busbar device can be improved.

[0101] As shown in FIG. 11, the thickness of the pole column 112 in the first direction X is d, satisfying: 3.7 mm < d < 8 mm. Since when the thickness d of the pole column 112 in the first direction X is larger, that is, the vertical space occupied by the pole column 112 increases, resulting in a decrease in the space utilization rate of the single battery; while when the thickness d of the pole column 112 in the first direction X is smaller, it will lead to an increase in the processing and assembly difficulty of the top cover 111, which will both increase the manufacturing cost of the single battery. Therefore, through testing, when the thickness d of the pole column 112 in the first direction X satisfies 3.7 mm < d < 8 mm, on the basis of improving the space utilization rate of the single battery, the processing and assembly of the top cover 111 are relatively easy, which is beneficial to reducing the manufacturing cost of the single battery.

[0102] When the numerical range of d is 3.7 mm < d < 8 mm, the space utilization rate of the single battery is relatively high, and the processing and assembly difficulty of the top cover 111 is relatively low, which is beneficial to reducing the manufacturing cost of the single battery.

[0103] Optionally, the numerical range of d is 5 mm < g < 7 mm to further narrow the value range of d, further improve the relatively high space utilization rate of the single battery, and at the same time reduce the manufacturing cost of the single battery.

[0104] In summary, the single battery provided by the embodiments of this application has at least the following advantages:

[0105] In the embodiment of the present application, since the single cell includes: a housing having a receiving cavity with an opening therein; a cell body disposed in the receiving cavity; and a top cover assembly connected to the opening side of the housing to seal the opening; the top cover assembly includes a top cover and a pole post, the top cover has a first direction, a pole post hole extending along the first direction is provided on the top cover, and the pole post is embedded in the pole post hole; a convex structure is provided on the outer periphery of the pole post hole on the side away from the housing of the top cover, and the convex structure is used to limit the pole post; wherein, the cross-sectional area perpendicular to the first direction of the pole post hole is s1, and the cross-sectional area perpendicular to the first direction of the top cover is s2, and the ratio of s1 to s2 satisfies: 0.015 < s1 / s2 < 0.15. In this way, on the one hand, since a convex structure is provided on the outer periphery of the pole post hole, not only can the pole post be limited, but also the mechanical strength at the pole post hole can be increased, effectively avoiding deformation of the top cover. On the other hand, since the ratio of the cross-sectional area s1 perpendicular to the first direction of the pole post hole to the cross-sectional area s2 perpendicular to the first direction of the top cover satisfies 0.015 < s1 / s2 < 0.15, within this numerical range, when the outer dimension of the pole post is increased adaptively, the influence of the corresponding pole post hole on the strength of the top cover is relatively small, so that the current output capacity of the single cell can be improved, and at the same time the overall strength of the top cover assembly can be improved, thereby improving the safety performance of the single cell.

[0106] The embodiment of the present application also provides a battery pack, which includes: the single cell according to any one of the above embodiments.

[0107] The embodiment of the present application also provides an electrical device, which includes: the battery pack according to the above embodiment.

[0108] It should be noted that in the embodiment of the present application, the structure of the single cell is the same as that of the single cell described in any of the above embodiments, and its beneficial effects are also similar, so details are not described herein.

[0109] The device embodiments described above are merely illustrative, where the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0110] In the description of this specification, reference to the terms "some optional embodiments," "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples.

[0111] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0112] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A single cell battery, wherein: The single battery comprises: A housing (1), wherein a receiving cavity with an opening is provided in the housing (1); A battery cell body, the battery cell body being disposed in the accommodating cavity; and a top cover assembly (11), the top cover assembly (11) being connected to the opening side of the shell (1) and covering the opening; the top cover assembly (111) comprising a top cover (111) and a pole (112); the top cover (111) having a first direction (X); a pole hole (1111) extending along the first direction (X) being provided on the top cover (111); and the pole (112) being embedded in the pole hole (1111); a protruding structure (1112) being provided on a side of the outer periphery of the pole hole (1111) away from the shell (1); the protruding structure (1112) being used to limit the pole (112); The cross-sectional area of ​​the pole hole (1111) perpendicular to the first direction (X) is s1, the cross-sectional area of ​​the top cover (111) perpendicular to the first direction (X) is s2, and the ratio of s1 to s2 satisfies: 0.015 <s1 / s2<0.15。 2. The single cell according to claim 1, wherein: The range of s1 is 50mm 2 ≤s1≤5000mm 2 .

3. The single cell according to claim 1, wherein: described s2 The range is 1000mm 2 ≤s2≤65000mm 2 .

4. The single cell according to claim 1, wherein: The protruding structure (1112) includes a peripheral side wall (11121) and a top wall (11122); One end of the peripheral side wall (11121) is connected to the top cover (111), the other end of the peripheral side wall (11121) extends in a direction away from the top cover (111), the top wall (11122) is connected to the other end of the peripheral side wall (11121), and the top wall (11122), the peripheral side wall (11121) and the top cover (111) enclose a receiving space (1113) for limiting the position of the pole (112).

5. The single cell according to claim 4, wherein: The pole (112) is provided with a boss (1121) along the circumferential direction, and the boss (1121) is embedded between the top wall (11122) and the top cover (111) to limit the pole (112) from escaping from the accommodating space (1113).

6. The single cell according to claim 5, wherein: The boss (1121) is a full circle of protrusions arranged along the circumference of the pole (112); or, the boss (1121) is a plurality of local protrusions arranged at intervals along the circumference of the pole (112).

7. The single cell according to claim 1, wherein: The top cover (111) further has a second direction (Y) and a third direction (Z), wherein the second direction (Y) and the third direction (Z) are perpendicular to the first direction (X). The width of the top cover (111) along the second direction (Y) is f, the length of the top cover (111) along the third direction (Z) is e, and the ratio of f to e satisfies: 0.15 <f / e<1。 8. The single cell according to claim 7, wherein: The range of f meets, 10mm <f<100mm。 9. The single cell according to claim 7, wherein: The range of f meets, 10mm <f<85mm。 10. The single cell according to claim 7, wherein: The range of e meets, 100mm <e<650mm。 11. The single cell according to claim 7, wherein: The range of e meets, 120mm <e<400mm。 12. The single cell according to claim 1, wherein: The thickness of the top cover (111) along the first direction (X) is g, which satisfies: 1 mm <g<3.5mm。 13. The single cell according to claim 1, wherein: The minimum distance between the edge of the pole hole (1111) and the edge of the top cover (111) is a, satisfying: a>3.5mm.

14. The single cell according to claim 1, wherein: Along the first direction (X), the pole (112) has a welding end surface (1122) facing away from the top cover (111), and the welding end surface (1122) is used for welding to an external current collecting device; The orthographic projection of the welding end surface (1122) along the first direction (X) is a first projection surface, and the maximum outer dimension of the first projection surface is c, which satisfies: 5mm <c<40mm。 15. The single cell according to claim 1, wherein: The top cover assembly (11) further comprises a plastic part (113), wherein the plastic part (113) is connected to a side of the protruding structure (1112) away from the housing (1), and at least a portion of the plastic part (113) extends between the protruding structure (1112) and the pole (112) to connect the protruding structure (1112) and the pole (112).

16. The single cell according to claim 1, wherein: The top cover assembly (11) further includes a sealing ring (114), which is sleeved outside the pole (112) and abuts against the top cover (111).

17. The single cell according to claim 16, wherein: The sealing ring (114) includes at least one of a plastic sealing ring and a foam sealing ring.

18. The single cell according to claim 1, wherein: The thickness of the pole hole (1111) along the first direction (X) is d, and the thickness d satisfies: 3.7 mm <d<8mm。 19. A battery pack, wherein: The battery pack comprises: the single battery according to any one of claims 1 to 18.

20. An electrical device, wherein: The electrical equipment includes the battery pack according to claim 19.

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