Battery cell, battery module and electric equipment

Abstract

The utility model relates to a battery cell, a battery module and electric equipment. The battery cell comprises a shell assembly, the shell assembly is of a composite structure, the shell assembly is cylindrical, the shell assembly comprises an outer shell and an inner shell which are overlaid inside and outside, a containing cavity is formed in the inner shell, the interior of the containing cavity is used for containing a roll core, and the two axial ends of the shell assembly are fixedly connected with a pole column and a bottom cover respectively; wherein the outer shell and the inner shell are made of different materials, and the structural strength of the inner shell is higher than that of the outer shell. The battery cell provided by the utility model has good safety performance, is lighter in weight, and has good conductivity, welding performance and anti-rust performance.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to battery cells, battery modules and electrical equipment. Background Art

[0002] Cylindrical battery cells are a type of battery with high energy density, high safety and broad application prospects. The advantages of cylindrical battery cells are their large single cell capacity and high energy density. Moreover, compared with square shell battery cell modules of the same size, when a single cell has thermal runaway, catches fire or explodes, the heat generated by the cylindrical battery cell module will be much smaller, and it has higher safety.

[0003] The cylindrical battery cells of the related technology are generally made of a single material such as nickel-plated steel shell, aluminum shell or stainless steel shell. The steel shell has high structural strength and good safety performance, but its weight is heavy, which is not conducive to improving the energy density of the battery cell, and the steel shell has poor electrical conductivity, rust resistance and welding performance; the aluminum shell is light and has good welding effect, but the structural strength is poor and the melting point is low, which can easily cause shell damage in the event of thermal runaway; the stainless steel shell has enhanced rust resistance, but its electrical conductivity is reduced, and it is heavy and has poor welding performance. Utility Model Content

[0004] In order to solve or partially solve the problems existing in the related art, the present application provides a battery cell, a battery module and an electrical device. The battery cell has good safety performance, is lighter, and has good electrical conductivity, welding and rust resistance.

[0005] The first aspect of the present application provides a battery cell, comprising:

[0006] A shell assembly, the shell assembly is a composite structure, the shell assembly comprises an outer shell and an inner shell which are stacked inside and outside, a receiving cavity is formed inside the inner shell, the receiving cavity is used to receive the winding core, and the two axial ends of the shell assembly are respectively fixedly connected with a pole and a bottom cover;

[0007] The outer shell and the inner shell are made of different materials, and the structural strength of the inner shell is higher than that of the outer shell.

[0008] In some embodiments, the outer shell is made of aluminum.

[0009] In some embodiments, the inner shell is made of at least one of titanium alloy, ceramic fiber, carbon fiber, and glass fiber.

[0010] In some embodiments, the shell assembly includes a main body and a top cover arranged at one axial end of the main body, the top cover and the main body are an integral structure; a pole hole is provided in the center of the top cover, and the pole is fixed in the pole hole; the top cover and the bottom cover are arranged opposite to each other in the axial direction, and the thickness of the top cover and / or the bottom cover is greater than the thickness of the main body.

[0011] In some embodiments, the thickness of the top cover is 0.3-0.6 mm; and / or,

[0012] The thickness of the bottom cover is 0.3-0.8 mm.

[0013] In some embodiments, the thickness of the inner shell is 0.1-0.4 mm; and / or,

[0014] The thickness of the outer shell is 0.1-0.3 mm.

[0015] In some implementations, the material of the bottom cover is the same as that of the outer shell, and the bottom cover is welded to the outer shell.

[0016] In some embodiments, the inner surface of the bottom cover is connected to the bottom busbar of the winding core;

[0017] The bottom cover is also provided with an explosion-proof valve and / or a liquid injection hole.

[0018] A second aspect of the present application provides a battery module, comprising:

[0019] A battery box, wherein a plurality of battery cells as described in the first aspect above are installed in the battery box.

[0020] A third aspect of the present application provides an electrical device, comprising the battery cell as described in the first aspect above.

[0021] The technical solution provided by this application may have the following beneficial effects:

[0022] The present application provides a battery cell, including a shell assembly, the shell assembly is a composite structure, the shell assembly includes an outer shell and an inner shell superimposed on each other, the inner shell has a receiving cavity formed inside, the receiving cavity is used to receive a winding core, and the two axial ends of the shell assembly are respectively fixedly connected with a pole and a bottom cover; wherein the outer shell and the inner shell are made of different materials, the density of the inner shell is less than the density of the outer shell, and the structural strength of the inner shell is higher than the structural strength of the outer shell. The battery cell provided by the present application has good safety performance, is more lightweight, and has good electrical conductivity, welding and rust resistance.

[0023] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0025] Figure 1 is a schematic diagram of the structure of a battery cell shown in an embodiment of the present application;

[0026] Figure 2 is an exploded diagram of a battery cell shown in an embodiment of the present application;

[0027] Figure 3 is a schematic diagram of the cooperation between the top cover and the main body of the battery cell shown in the embodiment of the present application;

[0028] Figure 4 It is a schematic diagram of the coordination between the bottom cover and the main body of the battery cell shown in the embodiment of the present application.

[0029] Figure numerals: 100, battery cell; 110, main body; 111, outer shell; 112, inner shell; 1111, outer shell side; 1112, outer shell top; 1121, inner shell side; 1122, inner shell top; 120, top cover; 121, pole hole; 130, pole; 140, bottom cover; 141, explosion-proof valve. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0031] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0032] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0033] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the 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 should not be understood as a limitation on the present application.

[0034] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0035] The cylindrical battery cells of the related technology are generally made of a single material such as nickel-plated steel shell, aluminum shell or stainless steel shell. The steel shell has high structural strength and good safety performance, but its weight is heavy, which is not conducive to improving the energy density of the battery cell, and the steel shell has poor electrical conductivity, rust resistance and welding performance; the aluminum shell is light and has good welding effect, but the structural strength is poor and the melting point is low, which can easily cause shell damage in the event of thermal runaway; the stainless steel shell has enhanced rust resistance, but its electrical conductivity is reduced, and it is heavy and has poor welding performance. In response to the above problems, the embodiments of the present application provide a battery cell with good safety performance, lighter weight, and good electrical conductivity, welding and rust resistance.

[0036] The technical solution of the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0037] Figure 1 is a schematic diagram of the structure of a battery cell shown in an embodiment of the present application; Figure 2 It is an exploded diagram of a battery cell shown in an embodiment of the present application.

[0038] See also Figure 1 and Figure 2 The present application provides a battery cell 100, including a shell assembly, which is a composite structure. The shell assembly includes an outer shell 111 and an inner shell 112 that are stacked inside and outside. The inner shell 112 has a receiving cavity formed inside, which is used to receive the winding core. The two axial ends of the shell assembly are respectively fixedly connected with a pole 130 and a bottom cover 140; wherein, the outer shell 111 and the inner shell 112 are made of different materials, the density of the inner shell 112 is less than that of the outer shell 111, and the structural strength of the inner shell 112 is higher than that of the outer shell 111. The battery cell 100 provided by the present application has good safety performance, is more lightweight, and has good electrical conductivity, welding and rust resistance.

[0039] The battery cell 100 of this embodiment is a cylindrical battery cell 100, the shell assembly is cylindrical, the pole 130 is arranged at one axial end of the shell assembly, and the bottom cover 140 is arranged at the other axial end of the shell assembly. The pole 130 can be a rivet pole 130, and the pole 130 can be riveted to the inner shell 112 and the outer shell 111 at the same time. The outer shell 111 and the inner shell 112 are formed into one body by including but not limited to pressing, ultrasound, gluing, etc. The outer shell 111 and the inner shell 112 are both cylindrical, the diameter of the inner shell 112 is smaller than the outer shell 111, and the inner shell 112 is located inside the outer shell 111. The two are arranged along the same axis to form a double-layer shell structure, and the outer shell 111 and the inner shell 112 have a gap or contact each other.

[0040] In this embodiment, the outer shell 111 is made of a material with low density and good conductivity, such as aluminum. In this way, the outer shell 111 is welded to the external aluminum bar during high voltage connection, which is the same metal welding and has good welding performance. The inner shell 112 can be made of a material with high structural strength and low density, for example, the material of the inner shell 112 is at least one of titanium alloy, ceramic fiber, carbon fiber, and glass fiber. In this way, when thermal runaway occurs inside the battery cell 100, the shell assembly is not easily damaged at high temperature, ensuring that pressure can be released from the bottom of the battery cell 100, effectively reducing the secondary harm of the ejecta to the electrical area during thermal runaway, and improving the safety of the battery cell 100 and electrical equipment.

[0041] See also Figure 3 and Figure 4 In some embodiments, the shell assembly includes a main body 110 and a top cover 120 provided at one axial end of the main body 110, the top cover 120 and the main body 110 are an integral structure; a pole hole 121 is provided in the center of the top cover 120, and the pole 130 is fixed in the pole hole 121; the top cover 120 and the bottom cover 140 are arranged opposite to each other in the axial direction, and the thickness of the top cover 120 is greater than the thickness of the main body 110.

[0042] In some embodiments, the outer shell 111 and the inner shell 112 extend from the edge of the battery cell 100 toward the axis L at the end where the pole 130 is located, thereby forming a top cover 120 that is integrated with the main body 110, that is, the top cover 120 is a partial structure of the outer shell 111 and the inner shell 112, and the pole hole 121 is formed in the center of the top cover 120. At least a portion of the pole 130 is placed in the pole hole 121 and is riveted to the outer shell 111 and the inner shell 112 at the same time. In this way, the connection strength between the shell assembly and the pole 130 can be improved.

[0043] See also Figure 3 and Figure 4 In this embodiment, the outer shell 111 includes an outer shell side 1111 and an outer shell top 1112; the inner shell 112 includes an inner shell side 1121 and an inner shell top 1122, the outer shell side 1111 and the inner shell side 1121 constitute the main body 110, and the outer shell top 1112 and the inner shell top 1122 constitute the top cover 120.

[0044] In some embodiments, the thickness of the top cover 120 is 0.3-0.6 mm.

[0045] In some embodiments, the material of the bottom cover 140 is the same as that of the outer shell 111, and the outer periphery of the bottom cover 140 is welded to the outer shell 111. In some embodiments, the material of the bottom cover 140 can be aluminum, which is the same metal as the outer shell 111, and the two have good welding properties.

[0046] In some embodiments, the thickness of the bottom cover 140 is the same as that of the top cover 120 , or the thickness of the bottom cover 140 is greater than that of the top cover 120 . In some embodiments, the thickness of the bottom cover 140 is 0.3-0.8 mm.

[0047] In some embodiments, the thickness of the top cover 120 and / or the bottom cover 140 is greater than the thickness of the housing body 110 .

[0048] In some embodiments, the thickness of the shell body 110 may be 0.2-0.7 mm, the thickness of the inner shell 112 may be equal to or greater than the thickness of the outer shell 111 , the thickness of the inner shell 112 may be 0.1-0.4 mm, and the thickness of the outer shell 111 may be 0.1-0.3 mm.

[0049] In some embodiments, the inner surface of the bottom cover 140 is connected to the bottom manifold of the winding core to realize the passage; the bottom cover 140 is also integrated with an explosion-proof valve 141 and / or a liquid injection hole. The shape of the explosion-proof valve 141 is not limited to a circle or an ellipse.

[0050] In this embodiment, since the inner shell 112 has a high structural strength, when thermal runaway occurs inside the battery cell 100, the shell assembly is not easily damaged at high temperature, ensuring that pressure can be released from the explosion-proof valve 141 at the bottom of the battery cell 100, which can improve the safety performance of the battery cell 100.

[0051] Compared with the steel shell notched explosion-proof valve at the bottom of the battery cell 100 in the related art, the explosion-proof valve 141 is arranged on the aluminum bottom cover 140 in the present application, which makes it easier to achieve stable directional valve opening and is safer than the single steel shell and aluminum shell in the related art.

[0052] In addition, the bottom cover 140 and the outer shell 111 are made of the same metal with good conductivity, and the welding performance and conductivity are better. The inner shell 112 and the outer shell 111 are made of low-density and rust-proof materials. Therefore, compared with the steel shell of the same thickness in the related art, the shell weight is reduced, and the weight of the shell assembly of the present application will be reduced to 45%-50% of the related art. The outer shell 111 is made of aluminum, which has good rust-proof function and better conductivity than the steel shell in the related art.

[0053] In some embodiments, the materials of the outer shell 111 and the inner shell 112 of the battery cell 100 of the present application can be interchangeable. For example, the structural strength of the inner shell 112 is lower than that of the outer shell 111. The material of the inner shell 112 can be aluminum, and the material of the outer shell 111 can be at least one of titanium alloy, ceramic fiber, carbon fiber, and glass fiber. In some embodiments, the present application only provides the inner shell 112 without the outer shell 111, and the material of the inner shell 112 can be titanium alloy.

[0054] The present application provides a battery module, characterized in that it includes a battery box, in which a plurality of battery cells 100 according to any of the above embodiments are installed.

[0055] The battery module provided in the present application has a lighter battery cell 100 therein and has better electrical conductivity, welding and rust resistance. Therefore, the battery module has the characteristics of being lighter and having better performance stability.

[0056] The present application also provides an electric device, including the battery cell 100 of any of the above embodiments, and the electric device may be a movable device such as a vehicle or an aircraft. The structure of the battery cell 100 may refer to the description of the above embodiments, and will not be repeated here.

[0057] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A battery cell, characterized in that: include: A shell assembly, the shell assembly is a composite structure, the shell assembly comprises an outer shell and an inner shell which are stacked inside and outside, a receiving cavity is formed inside the inner shell, the receiving cavity is used to receive the winding core, and the two axial ends of the shell assembly are respectively fixedly connected with a pole and a bottom cover; The outer shell and the inner shell are made of different materials, and the structural strength of the inner shell is higher than that of the outer shell.

2. The battery cell according to claim 1, characterized in that: The outer shell is made of aluminum.

3. The battery cell according to claim 1, characterized in that: The inner shell is made of at least one of titanium alloy, ceramic fiber, carbon fiber and glass fiber.

4. The battery cell according to claim 1, characterized in that: The shell assembly includes a main body and a top cover arranged at one axial end of the main body, the top cover and the main body are an integral structure; a pole hole is provided in the center of the top cover, and the pole is fixed in the pole hole; the top cover and the bottom cover are arranged opposite to each other in the axial direction, and the thickness of the top cover and / or the bottom cover is greater than the thickness of the main body.

5. The battery cell according to claim 4, characterized in that: The thickness of the top cover is 0.3-0.6 mm; and / or, The thickness of the bottom cover is 0.3-0.8 mm.

6. The battery cell according to claim 1, characterized in that: The thickness of the inner shell is 0.1-0.4 mm; and / or, The thickness of the outer shell is 0.1-0.3 mm.

7. The battery cell according to claim 3, characterized in that: The material of the bottom cover is the same as that of the outer shell, and the bottom cover and the outer shell are welded.

8. The battery cell according to claim 1, characterized in that: The inner surface of the bottom cover is connected to the bottom collector of the winding core; The bottom cover is also provided with an explosion-proof valve and / or a liquid injection hole.

9. A battery module, characterized in that: include: A battery box, wherein a plurality of battery cells according to any one of claims 1 to 8 are installed in the battery box.

10. An electrical device, characterized in that: Comprising the battery cell as described in any one of claims 1 to 8.

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