End cover assembly, battery monomer, battery and electric device

Abstract

The invention discloses an end cover assembly (10), a battery cell, a battery and an electric device. The end cover assembly (10) comprises an end cover (100), the end cover (100) comprises a positive terminal installation area and a negative terminal installation area, the end cover (100) at least comprises a first area surrounding the positive terminal installation area and a second area surrounding the negative terminal installation area, the first area is provided with a first surface (111) facing the battery cell assembly (30), and the second area is provided with a second surface (112) facing the battery cell assembly (30). The first surface (111) and the second surface (112) have a height difference along the thickness direction of the end cover (100). The end cover assembly (10) provided by the invention is applied to a battery monomer, and when the end cover assembly (10) is located below the battery cell assembly (30), the guide surface can enable the electrolyte to flow from high to low in the first surface (111) and the second surface (112), so that the electrolyte is concentrated, and the electrolyte can climb to the battery cell body along the tab.

Description

End cap assembly, battery cell, battery and electrical device Technical Field

[0001] The present application relates to the field of batteries, and in particular to an end cover assembly, a battery cell, a battery, and an electrical device. Background Art

[0002] As people become more aware of environmental protection, electric vehicles are rapidly gaining popularity in the automotive industry due to their energy-saving and environmentally friendly advantages. Electric vehicles use batteries as their power supply. The battery consists of a housing and end caps. The end caps fit over the housing, housing the battery cell assembly. The end caps are equipped with positive and negative terminals. The positive terminal connects to the positive tab, and the negative terminal connects to the negative tab.

[0003] When the battery is inverted, the end cap is located below the battery cell assembly, which causes some free electrolyte to be dispersed on the surface of the end cap and difficult to effectively climb to the battery cell along the tab, resulting in performance degradation of the battery during use due to poor electrolyte infiltration.

[0004] Summary of the Invention

[0005] In view of the above problems, the present application provides an end cover assembly, a battery cell, a battery and an electrical device, which can to a certain extent solve the problem of poor electrolyte infiltration and resulting battery performance degradation when the end cover is located below the battery cell assembly.

[0006] In a first aspect, the present application provides an end cap assembly, comprising: an end cap, the end cap comprising a positive terminal mounting area and a negative terminal mounting area, the end cap comprising at least a first area enclosed outside the positive terminal mounting area and a second area enclosed outside the negative terminal mounting area, the first area having a first surface facing the battery cell assembly, the second area having a second surface facing the battery cell assembly, and the first surface and the second surface having a height difference along the thickness direction of the end cap.

[0007] In the technical solution of the embodiment of the present application, the end cap assembly can be applied to the battery cell. When the end cap assembly is below the battery cell assembly, due to the height difference between the first surface and the second surface in the thickness direction of the end cap, the electrolyte will flow downward under the action of gravity, thereby making the electrolyte flow faster to the side with lower height among the first surface and the second surface, so that the electrolyte in the area with low surface height is more concentrated, so that the contact area between the electrode terminal connection in the area with low surface height and the electrolyte is larger, so that the electrolyte can climb along the electrode terminal connection ear surrounded by the low height area, thereby improving the efficiency of the electrolyte climbing along the negative electrode ear to the battery cell, and reducing the performance degradation of the battery due to poor electrolyte infiltration.

[0008] In some embodiments, the first surface is closer to the battery cell assembly than the second surface.

[0009] Since the first zone is arranged around the positive terminal mounting area and the second zone is arranged around the negative terminal mounting area, and the electrolyte climbs faster along the negative electrode ear than the positive electrode ear, the first surface of the first zone is set to be higher than the second surface of the second zone, so that the electrolyte is concentrated in the second zone, thereby facilitating the electrode liquid to climb along the negative electrode ear.

[0010] In some embodiments, the end cover further includes a transition zone, which is located between the positive terminal mounting area and the negative terminal mounting area, and the transition zone has a transition surface facing the battery cell assembly, and along the thickness direction of the end cover, the height of the transition surface is between the height of the first surface and the height of the second surface.

[0011] In this configuration, the transition zone can be used to accommodate or install other structures, and the configuration of the transition zone will not affect the flow direction of the electrolyte.

[0012] In some embodiments, the end cap includes an end plate and an insulating structure, and the first surface and the second surface are both located on a side of the insulating structure facing away from the end plate;

[0013] The thickness of at least a portion of the end plate covered by the first zone is greater than the thickness of at least a portion of the end plate covered by the second zone to form the height difference, and / or the thickness of at least a portion of the insulating structure covered by the first zone is greater than the thickness of at least a portion of the insulating structure covered by the second zone to form the height difference.

[0014] In this setting, the height difference between the first surface and the second surface can be achieved by changing the thickness of different areas of the end plate, or by changing the thickness of different areas of the insulating structure, or by changing the thickness of different areas of the insulating structure and the end plate.

[0015] In some embodiments, at least one of the first region and the second region is provided with a protrusion, and / or at least one of the first region and the second region is provided with a recess.

[0016] The arrangement of the protrusion and the recess can result in a difference in the distances that the first area and the second area extend into the shell, thereby resulting in a height difference between the first surface and the second surface.

[0017] In some embodiments, at least one of the first surface and the second surface includes a guide surface, and the guide surface includes at least one of an inclined plane, an inclined arc surface, and a stepped surface.

[0018] There are many ways to set the guide surface, which can be selected according to actual needs.

[0019] In some embodiments, at least one of the first surface and the second surface includes a guide surface, the guide surface includes at least one inclined segment and at least one transition segment, the inclination angle of the transition segment is smaller than the inclination angle of the inclined segment, and the inclined segments and the transition segments are alternately arranged.

[0020] The guide surface may be not only a continuously inclined surface but also a discontinuously inclined surface.

[0021] In some embodiments, the transition zone is provided with a pressure relief zone and / or a liquid injection hole.

[0022] In this arrangement, the provision of the pressure relief zone can improve the safety protection performance of the battery cell with the end cover assembly, and the provision of the injection hole facilitates the injection of electrolyte into the shell.

[0023] In some embodiments, at least one of the first surface and the second surface includes a guide surface, a height difference between the guide surface and the transition surface along the thickness direction of the end cover is present, and a gap is present between the guide surface and the transition area.

[0024] In this configuration, the gap can prevent the electrolyte from rapidly accumulating in the transition zone.

[0025] In some embodiments, the first surface includes a guide surface, and the length of the guide surface along the length direction of the end cap is less than or equal to 0.9 times the length of the first surface; and / or the second surface includes a guide surface, and the length of the guide surface along the length direction of the end cap is less than or equal to 0.9 times the length of the second surface.

[0026] In a second aspect, the present application further provides a battery cell, comprising: a shell, a cell assembly and the end cover assembly described in the above embodiment, wherein the cell assembly is arranged in the shell; and the end cover assembly covers the opening of the shell.

[0027] In the scenario where the battery cell is in the working position and the end cover assembly is below the battery cell assembly, the setting of the guide surface can make the electrolyte flow to the second zone faster, and the second zone is arranged around the negative terminal, and the negative terminal is connected to the negative electrode ear, which means that the electrolyte flows to the negative electrode ear faster, making it easier for the electrolyte to climb along the negative electrode ear, thereby improving the efficiency of the electrolyte climbing along the negative electrode ear to the battery cell and reducing the performance degradation of the battery due to poor electrolyte infiltration.

[0028] In some embodiments, the end cap assembly is located below the battery cell assembly.

[0029] In this arrangement, the end cap assembly is located below the battery cell assembly, and the guide surface on the end cap assembly facilitates the flow of electrolyte toward the negative electrode ear.

[0030] In a third aspect, the present application provides a battery comprising the battery cell in the above embodiment.

[0031] Since the battery includes the above-mentioned battery cell, it at least includes all the beneficial effects of the above-mentioned battery cell, which will not be described in detail here.

[0032] In a fourth aspect, the present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0033] Since the electrical device includes the above-mentioned battery, it has at least all the beneficial effects of the above-mentioned battery, which will not be described in detail here.

[0034] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0036] FIG1 is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0037] FIG2 is a schematic structural diagram of an end cap assembly according to some embodiments of the present application;

[0038] FIG3 is a first schematic cross-sectional view of an end cap assembly along the length direction according to some embodiments of the present application;

[0039] FIG4 is a second schematic cross-sectional view of the end cap assembly along the length direction according to some embodiments of the present application;

[0040] FIG5 is a third schematic diagram of a cross-sectional structure of an end cap assembly along the length direction according to some embodiments of the present application;

[0041] FIG6 is a fourth schematic diagram of a cross-sectional structure of an end cap assembly along the length direction according to some embodiments of the present application;

[0042] FIG7 is a fifth schematic diagram of a cross-sectional structure of an end cap assembly along the length direction according to some embodiments of the present application;

[0043] FIG8 is a sixth schematic diagram of a cross-sectional structure of an end cap assembly along the length direction according to some embodiments of the present application;

[0044] FIG9 is a seventh schematic diagram of a cross-sectional structure of an end cap assembly along the length direction according to some embodiments of the present application;

[0045] FIG10 is a partial enlarged view of point E in FIG9 .

[0046] The figure numbers in the specific implementation manner are as follows: 10. End cover assembly; 21. Positive terminal; 22. Negative terminal; 23. Liquid injection hole; 24. Explosion-proof valve; 30. Battery cell assembly; 31. Battery cell body; 32. Positive ear; 33. Negative ear; 40. Adapter; 50. Insulation shell; 60. Shell; 100. End cover; 101. Inner side; 102. Outer side; 111. First surface; 112. Second surface; 113. Transition surface; 120. End plate; 121. First body; 122. First thickened portion; 130. Insulation structure; 131. Second body; 132. Second thickened portion; 133. Limiting portion; 134. Recessed portion; 141. Inclined section; 142. Transition section. DETAILED DESCRIPTION

[0047] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0049] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0050] In the description of the embodiments of the present application, the term "plurality" refers to more than two (including two).

[0051] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0052] As environmental pollution becomes increasingly serious, people's environmental awareness is gradually increasing. At the same time, the rapid rise of the new energy industry has provided a broad space for the application and development of lithium-ion batteries. Lithium-ion batteries have the characteristics of high energy density, long cycle life, and good charge and discharge rate performance. They have been widely used. More and more electrical devices, such as mobile phones, laptops, power tools, and electric vehicles, choose lithium-ion batteries as their power source. People generally refer to lithium-ion batteries used in these electrical devices as power batteries. Power batteries generally include battery cells, which include a housing and a cell assembly. The housing includes a shell and an end cap assembly. The end cap assembly covers the top opening of the shell to form a storage space with the shell. The cell assembly is installed in the storage space. The cell assembly includes a cell body, which is provided with a positive tab and a negative tab. The end cap assembly is installed with a positive terminal and a negative terminal. The positive tab is connected to the positive terminal, and the negative tab is connected to the negative terminal. The inventors noticed that in some practical application scenarios, the battery cells need to be installed upside down, which causes the end cap assembly to be located below the battery cell assembly. Most of the electrolyte in the shell is located in the battery cell assembly. A small amount of electrolyte is squeezed out of the battery cell assembly due to hanging on the inner wall of the shell, or the battery cell assembly expands during use. The electrolyte located on the outside of the battery cell assembly is called free electrolyte. The free electrolyte flows to the end cap assembly. Since the amount of this part of the electrolyte is small, the flow of the small amount of electrolyte on the end cap assembly is more dispersed, making it difficult for the electrolyte free on the end cap assembly to climb up to the battery cell body in time. In other words, the electrolyte has poor infiltration, which can easily lead to performance degradation of the battery during use.

[0053] Based on the above considerations, in order to solve the problem of poor electrolyte infiltration when the end cover assembly is located below the battery cell assembly, the inventor has designed an end cover assembly after in-depth research, the end cover assembly includes an end cover, the end cover includes a positive terminal mounting area and a negative terminal mounting area, the end cover includes at least a first area surrounded by the outside of the positive terminal mounting area and a second area surrounded by the outside of the negative terminal mounting area, the first area has a first surface facing the battery cell assembly, and the second area has a second surface facing the battery cell assembly. By forming a height difference along the thickness direction of the end cover between the first surface and the second surface, when the end cover is below the battery cell structure, the electrolyte will flow downward due to the influence of gravity, and will flow to the first area or the second area with a lower surface, thereby converging the electrolyte so that the electrolyte can climb along the tab connected to the electrode terminal in the first area or the second area with a lower surface to the electrode sheet, thereby infiltrating the battery cell body.

[0054] The end cap assembly disclosed in the embodiments of the present application can be used for all batteries including battery cells and electrical devices including the batteries.

[0055] A battery cell is the smallest unit of a battery. As shown in FIG1 , a battery cell includes a housing 60 , an end cap assembly 10 , a cell assembly 30 , and other functional components.

[0056] The housing 60 is a component used to cooperate with the end cap assembly 10 to form an internal environment of the battery cell. The formed internal environment is used to accommodate the battery cell assembly 30, electrolyte, the end cap assembly 10 and other components.

[0057] The end cover assembly 10 covers the opening of the shell 60 . The end cover assembly 10 is specifically the following end cover assembly 10 .

[0058] In a battery cell, the end cap assembly 10 generally includes an end cap 100 and electrode terminals. The electrode terminals are mounted on the end cap 100 and are used to electrically connect to the cell assembly 30 to output or input electrical energy into or out of the battery cell. The electrode terminals include a positive terminal 21 and a negative terminal 22. The positive terminal mounting area of ​​the end cap 100 is mounted with the positive terminal 21, while the negative terminal 22 is mounted with the negative terminal mounting area of ​​the end cap 100.

[0059] The cell assembly 30 is the component in the battery cell where electrochemical reactions occur. The housing 60 may contain one or more cell assemblies 30. The cell assembly 30 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The portion of the positive and negative electrode sheets with active materials constitutes the cell body 31 of the cell assembly 30, the portion of the positive electrode sheet without active materials constitutes the positive electrode ear 32, and the portion of the negative electrode sheet without active materials constitutes the negative electrode ear 33. During the charge and discharge process of the battery, the positive and negative electrode active materials react with the electrolyte, and the ear is electrically connected to the electrode terminal to form a current loop. The ear includes a positive ear 32 and a negative ear 33. The positive ear 32 is used to electrically connect to the positive terminal 21, and the negative ear 33 is used to electrically connect to the negative terminal 22.

[0060] As shown in Figures 2 to 4, an embodiment of the present application provides an end cap assembly 10 for a battery cell, wherein the end cap assembly 10 includes an end cap 100, and the end cap 100 includes a positive terminal mounting area and a negative terminal mounting area. The end cap 100 includes at least a first area enclosed outside the positive terminal mounting area and a second area enclosed outside the negative terminal mounting area. The first area has a first surface 111 facing the battery cell assembly 30, and the second area has a second surface 112 facing the battery cell assembly 30. The first surface 111 and the second surface 112 have a height difference along the thickness direction of the end cap 100, that is, when the end cap assembly 10 is covered on the opening of the shell 60, the distance that the first area extends into the shell 60 is different from the distance that the second area extends into the shell 60, and the distance between the first surface 111 and the battery cell assembly 30 is different from the distance between the second surface 112 and the battery cell assembly 30.

[0061] The end cap 100 is a component that covers the opening of the housing 60 to isolate the internal environment of the battery cell from the external environment.

[0062] The positive terminal installation area is used to install the positive terminal 21 , and the positive terminal installation area may be a through hole that penetrates the end cover 100 along the thickness direction of the end cover 100 .

[0063] The negative terminal installation area is used to install the negative terminal 22 , and the negative terminal installation area may be a through hole that penetrates the end cover 100 along the thickness direction of the end cover 100 .

[0064] The end cover 100 has two opposite sides along the thickness direction. After the end cover 100 is covered on the shell 60, one side faces the inner side of the shell 60. This side of the end cover 100 faces the battery cell assembly 30 located on the inner side of the shell 60. This side of the end cover 100 is called the inner side 101, and the side opposite to the inner side 101 is located on the outer side of the shell 60. This side is called the outer side 102.

[0065] In the inner side 101, a portion of the area is located outside the positive terminal mounting area. This portion of the area is referred to as the first area. The first area is located outside the positive terminal mounting area. The first area can fully surround the positive terminal mounting area, that is, the first area forms a closed annular area, or the first area can partially surround the positive terminal mounting area, that is, the first area forms a semi-closed (or open) annular area. In Figure 3, the area outside the positive terminal 21 within the range marked B is the first area. The first area has a first surface 111 facing the battery cell assembly 30. A portion of the area is located outside the negative terminal mounting area. This portion of the area is referred to as the second area. The second area is located outside the negative terminal mounting area. The second area can fully surround the negative terminal mounting area, that is, the second area forms a closed annular area, or the second area can partially surround the negative terminal mounting area, that is, the second area forms a semi-closed (or open) annular area. In Figure 3, the area outside the negative terminal 22 within the range marked C is the second area. The second area has a second surface 112 facing the battery cell assembly 30.

[0066] The height of the first surface 111 in the thickness direction of the end cap 100, that is, the distance that the first surface 111 extends into the housing 60 when the end cap assembly 10 is closed on the housing 60, or in other words, the vertical distance between the first surface 111 and the reference plane, with the horizontal plane at the opening of the housing 60 as the reference plane, after the end cap assembly 10 is closed on the housing 60. The distance that different areas of the first surface 111 extend into the housing 60 can be the same or different.

[0067] The height of the second surface 112 in the thickness direction of the end cap 100, that is, the distance the second surface 112 extends into the housing 60 when the end cap assembly 10 is closed on the housing 60, or in other words, the vertical distance between the second surface 112 and the reference plane, with the horizontal plane of the opening of the housing 60 as the reference plane after the end cap assembly 10 is closed on the housing 60. Different areas of the second surface 112 can extend the same or different distances into the housing 60. In other words, compared to the first surface 111, the second surface 112 is closer to or farther away from the battery cell assembly 30.

[0068] There is a height difference between the first surface 111 and the second surface 112, that is, the height of the first surface 111 is greater than the height of the second surface 112, or the height of the second surface 112 is greater than the height of the first surface 111. When the height of the first surface 111 is greater than the height of the second surface 112, the distance that at least a portion of the first surface 111 extends into the housing 60 is greater than the distance that at least a portion of the second surface 112 extends into the housing 60. In other words, when the battery cell is inverted, with the end cap 100 located below the housing 60 and the battery cell assembly 30 located above the end cap 100, the inner side 101 serves as the top surface of the end cap 100. The distance between at least a portion of the first surface 111 and the battery cell assembly 30 is closer, and the distance between at least a portion of the second surface 112 and the battery cell assembly 30 is farther. A height difference is formed between at least a portion of the first surface 111 and at least a portion of the second surface 112, and the height of at least a portion of the second surface 112 is lower. In this way, the electrolyte flows to a lower height under the action of gravity, so that the amount of electrolyte in the second area where the second surface 112 is located is larger. Since the second area is arranged around the negative terminal 22, and the negative terminal 22 is connected to the negative electrode ear 33, the electrolyte gathered in the second area flows to the negative electrode ear 33 faster, making it easier for the electrolyte to climb along the negative electrode ear 33, thereby improving the efficiency of the electrolyte climbing along the negative electrode ear 33 to the battery cell, and reducing the performance degradation of the battery due to poor electrolyte infiltration.

[0069] Similarly, when the height of the second surface 112 is greater than the height of the first surface 111, the electrolyte accumulated in the first area where the first surface 111 is located flows to the positive electrode ear 32 faster, making it easier for the electrolyte to climb along the positive electrode ear 32, thereby improving the efficiency of the electrolyte climbing along the positive electrode ear 32 to the battery cell and reducing the performance degradation of the battery due to poor electrolyte infiltration.

[0070] In some embodiments, the height of the first surface 111 is greater than the height of the second surface 112. In this arrangement, when the battery cell is inverted, with the end cap 100 below the housing 60 and the cell assembly 30 above the end cap 100, the distance the first surface 111 extends into the housing 60 is greater than the distance the second surface 112 extends into the housing 60, facilitating the electrolyte to rise along the negative electrode tab 33.

[0071] The positive electrode ear 32 and the negative electrode ear 33 are made of different materials. For example, the positive electrode ear 32 can be made of aluminum, and the negative electrode ear 33 can be made of copper. Compared with the positive electrode ear 32, the negative electrode ear 33 is more conducive to the climbing of the electrolyte. Therefore, the height of the second surface 112 is set to be lower than the height of the first surface 111, so that the electrolyte is concentrated in the second area, so that the electrolyte can climb along the negative electrode ear 33 to the battery body 31.

[0072] In some embodiments, at least one of the first region and the second region is provided with a protrusion, and / or at least one of the first region and the second region is provided with a recess 134 .

[0073] The setting of the protrusion can increase the distance that the first surface 111 of the first zone or the second surface 112 of the second zone extends into the shell 60, and the setting of the recessed portion 134 can reduce the distance that the first surface 111 of the first zone or the second surface 112 of the second zone extends into the shell 60.

[0074] As shown in FIG3 , in one embodiment, the first region is provided with a protrusion. The provision of the protrusion increases the distance that the first surface 111 extends into the housing 60, thereby causing the second surface 112 to extend less than the distance that the first surface 111 extends into the housing 60. This facilitates the electrolyte to gather in the second region and rise along the negative electrode tab 33. Conversely, if the protrusion is provided only in the second region, the provision of the protrusion increases the distance that the second surface 112 extends into the housing 60, facilitating the electrolyte to gather in the first region and rise along the positive electrode tab 32.

[0075] As shown in Figure 4, in one embodiment, a recess 134 is provided in the second region. The provision of recess 134 reduces the distance that the second surface 112 extends into the housing 60, thereby reducing the distance that the second surface 112 extends into the housing 60 compared to the distance that the first surface 111 extends into the housing 60. This facilitates the electrolyte to gather in the second region and rise along the negative electrode tab. Conversely, if recess 134 is provided only in the first region, the provision of recess 134 reduces the distance that the first surface 111 extends into the housing 60, facilitating the electrolyte to gather in the first region and rise along the positive electrode tab 32.

[0076] As shown in Figure 5, in one embodiment, a protrusion or recess 134 is provided in each of the first and second regions. In one feasible configuration, the first region is provided with a protrusion and the second region is provided with a recess 134. In another configuration, both the first and second regions are provided with a protrusion, and the protrusion provided in the first region protrudes farther along the thickness of the end cap 100 than the protrusion provided in the second region. This configuration also facilitates the electrolyte to gather in the second region and rise along the negative electrode tab 33. In yet another configuration, both the first and second regions are provided with a recess 134, and the recess 134 provided in the first region protrudes farther along the thickness of the end cap 100 than the recess 134 provided in the second region. This also facilitates the electrolyte to gather in the second region and rise along the negative electrode tab 33.

[0077] The protrusion can be formed by increasing the thickness of a portion of the end cap 100, or by punching a convex portion from the outer side 102 toward the inner side 101 in a portion of the end cap 100. The recess 134 can be formed by reducing the thickness of a portion of the end cap 100, or by punching a convex portion from the inner side 101 toward the outer side 102 in a portion of the end cap 100, so that a groove is formed on the inner side 101 corresponding to the convex portion, and the groove forms the recess 134.

[0078] In some embodiments, a protrusion or recess 134 is formed by changing the thickness of the end cap 100. In this arrangement, the outer side 102 of the end cap 100 can be a plane. Hereinafter, the end cap assembly 10 will be further described with the outer side 102 being a plane and the protrusion or recess 134 formed by changing the thickness of the end cap 100. In this case, the difference in the distance the guide surface extends into the housing 60 can be reflected by the difference in the thickness of the end cap 100, that is, the thicker the end cap 100, the greater the distance it extends into the housing 60. In this case, the thickness of at least part of the first zone is greater than the thickness of at least part of the second zone. In Figures 3 to 6, the thickness of the first zone is H1, and the thickness of the second zone is H3. H1>H3.

[0079] As shown in Figures 3 to 8, in some embodiments, the end cap 100 includes an end plate 120 and an insulating structure 130. The insulating structure 130 is located on the side of the end plate 120 facing the battery cell assembly 30. The side of the insulating structure 130 adjacent to the battery cell assembly 30 includes a first surface 111 and a second surface 112. When the insulating structure 130 is made of plastic, it can be referred to as lower plastic.

[0080] The thickness of at least a portion of the end plate 120 covered by the first zone is greater than the thickness of at least a portion of the end plate 120 covered by the second zone, and / or the thickness of at least a portion of the insulating structure 130 covered by the first zone is greater than the thickness of at least a portion of the insulating structure 130 covered by the second zone.

[0081] In this setting, the height difference between the first surface 111 and the second surface 112 can be achieved by changing the thickness of different areas of the end plate 120, or by changing the thickness of different areas of the insulating structure 130 to form the height difference between the first surface 111 and the second surface 112, or by changing the thickness of different areas of the insulating structure 130 and the end plate 120 to achieve the height difference between the first surface 111 and the second surface 112.

[0082] For example, in Figure 6, the thickness of a portion of the end plate 120 is increased by changing the thickness of the portion, thereby increasing the height of the first surface 111 relative to the height of the second surface 112. Alternatively, the first surface 111 is closer to the cell assembly 30 than the second surface 112. The end plate 120 includes a first body 121 and a first thickened portion 122. The first body 121 is a plate-like structure. The first thickened portion 122 is connected to the first body 121 and is used to increase the thickness of a portion of the end plate 120, thereby increasing the thickness of the end cap 100. The first body 121 and the first thickened portion 122 can be made of the same material or different materials. The first thickened portion 122 can be made of a metal material or an alloy. The first body 121 and the first thickened portion 122 can be integrally formed or fixedly connected. For example, the first body 121 and the first thickened portion 122 can be manufactured by welding, casting, stamping, or by a process such as casting.

[0083] In some embodiments, as shown in FIG3 , the thickness of a portion of the insulating structure 130 is increased by changing the thickness of the portion, so that the height of the first surface 111 is greater than the height of the second surface 112, or in other words, the first surface 111 is closer to the battery cell assembly 30 than the second surface 112. The insulating structure 130 includes a second body 131 and a second thickened portion 132. The second body 131 is a plate-like structure. The second thickened portion 132 is connected to the second body 131 and is used to increase the thickness of a portion of the insulating structure 130, thereby increasing the thickness of the end cap 100. The second body 131 and the second thickened portion 132 can be made of the same material or different materials. The second thickened portion 132 can be a special insulating material (polysulfone, polyarylate, polytetrafluoroethylene, polyimide, etc.), a general insulating material (polystyrene, polypropylene, polyethylene, etc.), a thermosetting plastic (polyurethane, furan, allyl ester, phenolic, unsaturated polyester, silicone, amino plastic, etc.), or an engineering plastic (polycarbonate, thermoplastic polyester, nylon, modified polyphenylene ether, thermoplastic polyester, etc.). The second body 131 and the second thickened portion 132 can be integrally formed or fixedly connected. For example, the second body 131 and the second thickened portion 132 can be manufactured by processes such as plastic molding, injection molding, rotational molding, extrusion molding, thermoforming, compression molding, and hollow molding.

[0084] In some embodiments, a stopper 133 may be provided at the first side edge region of the insulating structure 130. The stopper 133 is configured to contact the inner wall of the housing 60, thereby increasing the contact area between the insulating structure 130 and the housing 60 and reducing relative shaking between the end cap assembly 10 and the housing 60. When the stopper 133 is provided, both the first surface 111 and the second surface 112 are located inside the stopper 133.

[0085] In Figures 3 to 10, the height of the first surface 111 is greater than the height of the second surface 112, or in other words, the first surface 111 is closer to the battery cell assembly 30 than the second surface 112; that is, when this end cap assembly 10 is applied to a battery cell and the battery cell is inverted, the electrolyte flows from the first area to the second area.

[0086] In Figures 3 to 6, both the first surface 111 and the second surface 112 can be horizontally arranged planes. In Figure 3, the first surface 111 is made into a horizontally arranged plane by uniformly increasing the thickness of a portion of the insulating structure 130 in the first zone. In Figure 4, the second surface 112 is made into a horizontally arranged plane by uniformly reducing the thickness of a portion of the insulating structure 130 in the second zone. In Figure 5, on the one hand, the thickness of a portion of the insulating structure 130 in the first zone is increased, and on the other hand, the thickness of a portion of the insulating structure 130 in the second zone is reduced, so that both the first surface 111 and the second surface 112 are planes parallel to the horizontal plane. In Figure 6, the first surface 111 is made into a horizontally arranged plane by increasing the thickness of a portion of the end plate 120 in the first zone.

[0087] In some embodiments, at least one of the first surface 111 and the second surface 112 includes a guide surface, and the guide surface includes at least one of an inclined plane, an inclined arc surface, and a stepped surface.

[0088] In FIG7 , first surface 111 includes a guide surface, which is an inclined plane. The guide surface causes the distance that first surface 111 extends into housing 60 to gradually decrease within a certain range, from a direction away from second surface 112 toward a direction closer to second surface 112. In the cross-section shown in FIG7 , first surface 111 is provided with a guide surface on the side of positive terminal 21 away from negative terminal 22, while the first surface 111 is not provided with a guide surface on the side of positive terminal 21 closer to negative terminal 22.

[0089] In FIG8 , the first surface 111 includes a guide surface, which is a stepped surface. The guide surface allows the distance that the first surface 111 extends into the housing 60 to decrease gradually in a stepped manner from a direction away from the second surface 112 toward a direction close to the second surface 112 within a certain range.

[0090] In Figures 9 and 10 , the guide surface includes at least one inclined section 141 and at least one transition section 142. The inclination angle of transition section 142 is smaller than that of inclined section 141, and inclined sections 141 and transition sections 142 are arranged alternately. In Figure 10 , inclined section 141 is inclined relative to the horizontal plane, and transition section 142 is inclined relative to the horizontal plane, such that the inclination angle of transition section 142 is smaller than that of inclined section 141.

[0091] As can be seen from the above, there are multiple ways to set the guide surface, which can be selected according to actual needs.

[0092] As shown in Figures 3 to 8, in some embodiments, the end cap 100 further includes a transition region having a transition surface 113 facing the battery cell assembly 30. The transition region is located between the positive terminal mounting area and the negative terminal mounting area. Along the thickness direction of the end cap 100, the height of the transition surface 113 is located between the height of the first surface 111 and the height of the second surface 112. In other words, the distance that the transition surface 113 extends into the housing 60 is less than or equal to the distance that the first surface 111 extends into the housing 60, and the distance that the transition surface 113 extends into the housing 60 is greater than or equal to the distance that the second surface 112 extends into the housing 60. In Figure 3, the area of ​​the end cap 100 within the range marked D, which is located around the injection hole 23 and the explosion-proof valve 24, is the transition region. The transition region has the transition surface 113 facing the battery cell assembly 30. When the outer side 102 of the end cap 100 is planar, the distance that the transition surface 113 extends into the housing 60 can be reflected by the thickness of the transition zone on the end cap 100. If the thickness of the transition zone is H2, then H2 satisfies: H3 ≤ H2 < H1, or H3 < H2 ≤ H1. The transition zone can be used to accommodate or install other structures. Because the distance that the transition surface 113 extends into the housing 60 is less than or equal to the distance that the first surface 111 extends into the housing 60, when the end cap assembly 10 is below the battery cell assembly 30, the height of the transition surface 113 is the same as or lower than the height of the first surface 111. Because the distance that the transition surface 113 extends into the housing 60 is greater than or equal to the distance that the second surface 112 extends into the housing 60, when the end cap assembly 10 is below the battery cell assembly 30, the height of the transition surface 113 is the same as or higher than the height of the second surface 112. From the above, it can be seen that after the transition surface 113 is provided, the provision of the transition surface 113 will not affect the flow direction of the electrolyte. When the end cover assembly 10 is below the battery cell assembly 30, the electrolyte in the first zone will flow to the second zone through the transition zone.

[0093] In some embodiments, the transition region is provided with a pressure relief region and / or a liquid injection hole 23. In this arrangement, the pressure relief region and / or the liquid injection hole 23 can be provided between the positive terminal mounting area and the negative terminal mounting area. The provision of the pressure relief region can improve the safety and protection performance of the battery cell to which the end cap assembly 10 is applied, and the provision of the liquid injection hole 23 facilitates the injection of electrolyte into the housing 60.

[0094] The pressure relief area is used to release internal pressure when the internal pressure or temperature of the battery cell reaches a threshold. It can be provided with explosion-proof notches, or it can be provided with a through-hole, in which an explosion-proof valve 24 is installed. In some cases, part of the structure of the explosion-proof valve 24 protrudes from the transition surface 113. That is, after the end cap assembly 10 is installed on the housing 60, the explosion-proof valve 24 partially extends into the interior of the housing 60. In this case, the electrolyte flows to the second surface 112 through the area around the explosion-proof valve 24 on the transition surface 113.

[0095] The injection hole 23 is used to inject electrolyte into the housing 60. The injection hole 23 is a through hole that penetrates the end cap 100 along the thickness direction of the end cap 100. Alternatively, a boss can be provided in the transition zone, and the injection hole 23 passes through the end cap 100 and the boss. The provision of the boss can increase the length of the injection hole 23, thereby facilitating cooperation with the injection structure and facilitating the sealing of the injection hole 23. After the injection is completed, a sealing structure can be provided on the side of the injection hole 23 facing away from the housing 60. The sealing structure is used to seal the injection hole 23. When the boss is provided in the transition zone, after the end cap assembly 10 is installed on the housing 60, the boss extends into the interior of the housing 60. In this case, the electrolyte flows to the second surface 112 via the transition surface 113 located around the boss.

[0096] In some embodiments, there is a gap between the guide surface and the transition surface 113. In this arrangement, since there is a gap between the guide surface and the transition surface 113, the electrolyte can be prevented from accumulating rapidly in the transition zone. Due to the arrangement of the guide surface, a height difference occurs between the first surface 111 and the second surface 112. In the process of the electrolyte flowing from the first surface 111 to the second surface 112, it flows from a high place to a low place. When the electrolyte flows to the height change area, its flow speed will become faster, and the impact force on the surface of the inner side 101 of the end cover 100 will also increase. The guide surface is arranged at a certain gap from the transition surface 113, so that the flow speed of the electrolyte at the gap is in a state of slowing down or being relatively gentle, so that the electrolyte flowing into the transition zone reduces the impact on the pressure relief zone set in the transition zone.

[0097] In some embodiments, the first surface 111 includes a guide surface, and the length of the guide surface along the length direction of the end cover 100 is less than or equal to 0.9 times the sum of the lengths of the first surface 111, and / or the second surface 112 includes a guide surface, and the length of the guide surface along the length direction of the end cover 100 is less than or equal to 0.9 times the sum of the lengths of the second surface 112.

[0098] It should be noted that, on the end cap 100, the first surface 111 and the second surface 112 are continuously or spaced apart along the length direction of the end cap 100. In other words, when the positive terminal 21 and the negative terminal 22 are mounted on the end cap 100, the positive terminal 21 and the negative terminal 22 are spaced apart along the length direction of the end cap 100.

[0099] Because the first region surrounds the positive terminal mounting area, if the dimensions of the positive terminal mounting area are the same as those of the first region along the width of the end cap 100, the positive terminal mounting area extends through the first region along the width of the end cap 100. Consequently, the positive terminal mounting area divides the first surface 111 into two sections along the length of the end cap 100. The length of the first surface 111 along the length of the end cap 100 is the sum of the length of the section located on one side of the positive terminal 21 and the length of the section located on the other side of the positive terminal 21. If the dimensions of the positive terminal mounting area along the width of the end cap 100 are smaller than the dimensions of the first surface 111, the positive terminal mounting area does not extend through the first region. Consequently, a portion of the first surface 111 is divided into two sections along the length by the positive terminal mounting area. The total length of the two separated sections is the sum of the length of the section located on one side of the positive terminal 21 and the length of the section located on the other side of the positive terminal 21. The total length of the two separated sections is the length of the first surface 111 at that location. The other portion of the first surface 111 is a complete section.

[0100] In the cross-section shown in FIG7 , the positive terminal mounting area divides the first surface area into two sections in the length direction of the end cap 100 , and the length of the first surface 111 along the length direction of the end cap 100 is the sum of the length L1 of a section located on one side of the positive terminal 21 and the length L2 located at the other end of the positive terminal 21 .

[0101] Because the second region surrounds the negative terminal mounting region, if the negative terminal mounting region and the second region are the same size along the width of the end cap 100, the negative terminal mounting region divides the second region into two sections along the length of the end cap 100. The length of the second surface 112 along the length of the end cap 100 is the sum of the length of the section located on one side of the negative terminal 22 and the length located on the other side of the negative terminal 22. If the negative terminal mounting region is smaller than the second region along the width of the end cap 100, a portion of the second surface 112 is divided into two sections along the length of the end cap 100 by the negative terminal mounting region. The length of this portion of the second surface 112 along the length of the end cap 100 is the sum of the length of the section located on one side of the negative terminal 22 and the length located on the other side of the negative terminal 22. The other portion of the second surface 112 is a complete section.

[0102] In the cross-section shown in FIG5 , the negative terminal mounting area divides the second surface 112 into two sections in the length direction of the end cap 100 , and the length of the second surface 112 along the length direction of the end cap 100 is the sum of the length L3 of the section located on one side of the negative terminal 22 and the length L4 located at the other end of the negative terminal 22 .

[0103] When a guide surface is provided on the first surface 111, the length of the guide surface along the length direction of the end cap 100 is less than or equal to 0.9 times the sum of the lengths of the first surface 111. In other words, the length of the guide surface provided on the first surface 111 is less than or equal to 0.9(L1+L2). When a guide surface is provided on the second surface 112, the length of the guide surface along the length direction of the end cap 100 is less than or equal to 0.9 times the sum of the lengths of the second surface 112. In other words, the length of the guide surface provided on the second surface 112 is less than or equal to 0.9(L3+L4). This configuration facilitates control of the gap between the guide surface and the transition surface 113.

[0104] As shown in Figure 1, an embodiment of the present application provides a battery cell, including: a shell 60, a battery cell assembly 30 and an end cover assembly 10 provided in any of the above embodiments, the battery cell assembly 30 is arranged in the shell 60, and the end cover assembly 10 covers the opening of the shell 60.

[0105] Battery cells can be used in electrical devices that use batteries as power sources or in various energy storage systems that use batteries as energy storage elements.

[0106] The opening of the housing 60 may be provided at the top, bottom or side. The provision of the opening facilitates the installation of structures such as the battery cell assembly 30 into the interior of the housing 60 .

[0107] The end cover assembly 10 covers the opening of the housing 60 to prevent the battery cell assembly 30 and other structures installed in the housing 60 from being separated from the housing 60 .

[0108] The battery cell assembly 30 includes a single battery cell, a positive tab 32, and a negative tab 33. The end cap assembly 10 also includes a positive terminal 21 and a negative terminal 22 connected to the end cap 100. The positive tab 32 and the positive terminal 21 are electrically connected via an adapter 40, and the negative tab 33 and the negative terminal 22 are electrically connected via another adapter 40. A liquid injection hole 23 and an explosion-proof valve 24 are also provided on the end cap 100 between the positive terminal 21 and the negative terminal 22.

[0109] The battery cell may further include an insulating shell 50 , which is located between the battery cell body 31 and the housing 60 and serves to insulate the battery cell body 31 from the housing 60 .

[0110] In some embodiments, the end cap assembly 10 is located below the battery cell assembly 30. In such a battery cell, the end cap assembly 10 provided by any of the above embodiments is more suitable.

[0111] The present application provides a battery, which includes the battery cell in the above embodiment.

[0112] The battery includes a box body and a battery cell, wherein the battery cell is accommodated in the box body. The box body is used to provide a space for accommodating the battery cell, and the box body can adopt a variety of structures.

[0113] In a battery, there can be multiple battery cells, which can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell structure is housed in a box. Of course, a battery can also be formed by first connecting multiple battery cells in series, in parallel, or in a hybrid connection to form a battery module, and then connecting multiple battery modules in series, in parallel, or in a hybrid connection to form a whole, which is then housed in a box. The battery may also include other structures, for example, the battery may also include a busbar component for achieving electrical connection between multiple battery cells.

[0114] Each battery cell can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell can be cylindrical, flat, rectangular, or in other shapes.

[0115] Since the battery includes the battery cell provided by the above embodiment, and the end cap assembly 10 provided by the above embodiment is applied in the battery cell, the battery at least includes all the advantages of the above end cap assembly 10 .

[0116] The present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0117] Since the electrical device includes the above-mentioned battery, it has at least all the beneficial effects of the above-mentioned battery, which will not be described in detail here.

[0118] Electrical devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery-powered vehicles, electric cars, ships, spacecraft, etc. Electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0119] For the convenience of explanation, the following embodiments are described by taking a vehicle as an example of an electrical device in one embodiment of the present application. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery is provided inside the vehicle, and the battery can be provided at the bottom, head or tail of the vehicle. The battery can be used to power the vehicle, for example, the battery can be used as an operating power source for the vehicle. The vehicle may also include a controller and a motor, and the controller is used to control the battery to power the motor, for example, for starting, navigating and operating power requirements of the vehicle during driving.

[0120] In some embodiments of the present application, the battery can serve not only as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An end cap assembly, characterized in that: include: An end cover, the end cover includes a positive terminal mounting area and a negative terminal mounting area, the end cover includes at least a first area surrounded by the outside of the positive terminal mounting area and a second area surrounded by the outside of the negative terminal mounting area, the first area has a first surface facing the battery cell assembly, the second area has a second surface facing the battery cell assembly, and the first surface and the second surface have a height difference along the thickness direction of the end cover.

2. The end cap assembly according to claim 1, wherein: The first surface is closer to the battery cell assembly than the second surface.

3. The end cap assembly according to claim 1 or 2, characterized in that: The end cover also includes a transition zone, which is located between the positive terminal mounting area and the negative terminal mounting area. The transition zone has a transition surface facing the battery cell assembly, and along the thickness direction of the end cover, the height of the transition surface is between the height of the first surface and the height of the second surface.

4. The end cap assembly according to any one of claims 1 to 3, characterized in that: The end cover comprises an end plate and an insulating structure, wherein the first surface and the second surface are both located on a side of the insulating structure facing away from the end plate; The thickness of at least a portion of the end plate covered by the first zone is greater than the thickness of at least a portion of the end plate covered by the second zone to form the height difference; and / or the thickness of at least a portion of the insulating structure covered by the first zone is greater than the thickness of at least a portion of the insulating structure covered by the second zone to form the height difference.

5. The end cap assembly according to any one of claims 1 to 4, characterized in that: At least one of the first region and the second region is provided with a protrusion, and / or at least one of the first region and the second region is provided with a recess.

6. The end cap assembly according to any one of claims 1 to 4, characterized in that: At least one of the first surface and the second surface includes a guide surface, and the guide surface includes at least one of an inclined plane, an inclined arc surface, and a step surface.

7. The end cap assembly according to any one of claims 1 to 4, characterized in that: At least one of the first surface and the second surface includes a guide surface, the guide surface includes at least one inclined section and at least one transition section, the inclination angle of the transition section is smaller than the inclination angle of the inclined section, and the inclined sections and the transition sections are alternately arranged.

8. The end cap assembly according to claim 3, wherein: The transition zone is provided with a pressure relief zone and / or a liquid injection hole.

9. The end cap assembly according to claim 8, wherein: At least one of the first surface and the second surface includes a guide surface, a height difference between the guide surface and the transition surface along a thickness direction of the end cover is provided, and a gap is provided between the guide surface and the transition area.

10. The end cap assembly according to claim 9, wherein: The first surface includes a guide surface, and the length of the guide surface along the length direction of the end cover is less than or equal to 0.9 times the length of the first surface; and / or the second surface includes a guide surface, and the length of the guide surface along the length direction of the end cover is less than or equal to 0.9 times the length of the second surface.

11. A battery cell, characterized in that: include: A shell, a battery cell assembly and an end cover assembly as described in any one of claims 1 to 10, wherein the battery cell assembly is arranged in the shell; and the end cover assembly covers the opening of the shell.

12. The battery cell according to claim 11, characterized in that: The end cover assembly is located below the battery core assembly.

13. A battery, characterized in that: include: A battery cell as claimed in claim 11 or 12.

14. An electrical device, characterized in that: Comprising a battery as claimed in claim 13, the battery is used to provide electrical energy.

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