Battery monomer, battery and electric device

Abstract

The utility model discloses a battery monomer, a battery and a power utilization device. The battery cell includes: a case; the at least one electrode assembly is arranged in the shell; wherein the outer surface of the housing facing away from the interior thereof is at least partially a uniform or non-uniform rough surface. According to the battery monomer disclosed by the embodiment of the invention, the outer surface of the shell is arranged to be the uniform or non-uniform rough surface, namely, the roughness of the outer surface of the shell is increased, so that the adhesion of the blue film to the outer surface of the shell is enhanced when the shell is wrapped by the blue film in the later period.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to a battery monomer, a battery and an electric device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development. Moreover, with the development of the new energy vehicle industry, the use scenarios of power batteries are becoming more and more diversified, and the size of the battery cell is also constantly adjusted, tending to be light and thin. In addition, after the power battery, especially the square aluminum shell battery cell, is assembled and discharged, a layer of outer film, such as the commonly known blue film, is usually wrapped on the surface of the battery cell. On the one hand, it can prevent the battery from being scratched, scratched, and impurities introduced, and play a protective role for the battery shell. On the other hand, it can prevent the shell from being short-circuited with the external circuit, and play an insulating protection role. CONTENT OF THE UTILITY MODEL

[0003] In view of the above problems, the present application provides a battery monomer, a battery and an electric device, wherein the cell shell is configured to enhance the wrapping of the insulating film such as the blue film on the shell after the cell is discharged, and if necessary, to facilitate the bonding of the aluminum shell and the module side plate, thereby facilitating the later module vibration, impact and other tests.

[0004] In the first aspect, the present application provides a battery monomer, comprising: a shell; at least one electrode assembly arranged inside the shell; wherein the outer surface of the shell facing away from the inside is at least partially rough. By setting the outer surface of the battery shell to be all or part of the rough surface, in other words, even if the roughness of the rough surface part is increased relative to the rest of the outer surface part, the bonding effect of the shell and the insulating film such as the blue film to be wrapped later is enhanced, and if necessary, the bonding effect of the shell side wall and the module side plate can also be enhanced.

[0005] In some embodiments, the roughness of the rough surface is in the range of 1 μm to 100 μm. In order to meet the different bonding and adhesion strengths between the shell and the blue film and / or the module side plate, the appropriate roughness of the rough surface can be selected as needed.

[0006] In some embodiments, the shell is a box-shaped structure, which is open on one side along a first direction and at least includes: a first wall opposite to the opening; a second wall, a third wall, a fourth wall and a fifth wall, which are sequentially connected end to end and connect the opening to the first wall, wherein the third wall and the fifth wall are oppositely arranged along a second direction perpendicular to the first direction, and the second wall and the fourth wall are oppositely arranged along a third direction perpendicular to the first direction and the second direction; the outer surface of the shell at least includes the outer surface of the first wall to the fifth wall. Such a shell is conducive to wrapping the insulating film such as the blue film later, and is also convenient to be assembled into a battery module.

[0007] In some embodiments, at least part of the outer surface of one or more of the first to fifth walls of the shell is roughened. By increasing the roughness of the local position of the shell surface, the bonding effect of the back of the shell, such as an aluminum shell, and the blue film, and / or the aluminum shell and the module side plate, can be precisely enhanced, and the processing area of the outer surface of the shell can be reduced.

[0008] In some embodiments, the outer surface of the second wall and the fourth wall of the shell is roughened. This arrangement can prevent the bottom of the blue film on the side wall from being lifted, and can enhance the bonding force of the middle part of the side wall where the blue film is not pasted and the module side wall, facilitating the later vibration, impact and other tests of the module.

[0009] In some embodiments, at least the side edge part of the outer surface of the second wall and the fourth wall of the shell adjacent to the third wall and the fifth wall, respectively, is roughened. In this way, the bonding effect of the blue film when wrapped around the edge part of the side wall of the shell, such as an aluminum shell, can be further precisely enhanced.

[0010] In some embodiments, the middle part of the outer surface of the second wall and the fourth wall, except for the side edge part adjacent to the third wall and the fifth wall, is roughened. In this way, the bonding and adhesion force of the middle part of the outer surface of the side wall that will not be wrapped with the blue film to the module side plate through structural adhesive in the later stage can be precisely enhanced, facilitating the later vibration, impact and other tests of the module.

[0011] In some embodiments, in the case of non-uniform roughening, the outer surface of one or more of the first to fifth walls of the shell is roughened, and the roughness changes in a gradient along a corresponding one or two of the first, second and third directions. By increasing the roughness of the surface of the shell, such as an aluminum shell, in a gradient, the bonding effect of the aluminum shell and the blue film, and / or the aluminum shell and the module side plate can also be precisely enhanced.

[0012] In some embodiments, the outer surface of one wall of the first to fifth walls of the shell to one or more walls adjacent to the one wall is roughened, and the roughness changes continuously in a gradient from the one wall to the corresponding adjacent wall. This continuous gradient increase in the surface roughness between different walls can precisely enhance the bonding effect of the aluminum shell and the blue film in the later stage.

[0013] In some embodiments, the outer surface of one or more of the first to fifth walls of the shell is roughened, and the roughness increases in a gradient from the middle of the two opposite sides or the middle of the four opposite sides. With this arrangement, when the blue film is wrapped in the later stage, the pasting effect of the blue film at the edge of the corresponding wall is enhanced.

[0014] In some embodiments, the corresponding four edge portions of the outer surfaces of the second wall and the fourth wall are rough surfaces whose roughness is symmetrically gradiently increased from the four edges toward the middle. This can prevent the problem of the back of the blue film being raised at the side of the shell, such as an aluminum shell, especially at the bottom.

[0015] In some embodiments, the second wall and the fourth wall have a size along the second direction that is smaller than the size of the third wall and the fifth wall along the third direction. The square shell battery structure of this structure is relatively flat, suitable for later wrapping of the blue film, and is also easy to assemble and transport.

[0016] In a second aspect, the present application provides a battery comprising the battery cell in the above embodiments.

[0017] In a third aspect, the present application provides an electric device comprising the battery in the above embodiments, wherein the battery is used to provide electric energy.

[0018] The above description is only a summary of the technical solutions of the present application. In order to enable the technical means of the present application to be more clearly understood, and to be implemented according to the content of the description, and in order to enable the above and other purposes, characteristics and advantages of the present application to be more apparent and easy to understand, the following specific embodiments of the present application are described in detail. BRIEF DESCRIPTION OF DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments, and are not to be considered as limitations on the present application. Moreover, in the drawings, like reference numerals refer to similar components throughout the various drawings. In the drawings:

[0020] Figure 1 Structure diagram of a vehicle of some embodiments of the present application;

[0021] Figure 2 Exploded structure diagram of a battery of some embodiments of the present application;

[0022] Figure 3 Exploded structure diagram of a battery cell of some embodiments of the present application;

[0023] Figure 4 Perspective view of a shell of a battery cell of some embodiments of the present application, from one side of which an opening can be seen;

[0024] Figure 5 Diagram of a bottom wall of a shell of a battery cell of some embodiments of the present application, opposite the opening;

[0025] Figure 6 Diagram of one of the two side walls of a shell of a battery cell of some embodiments of the present application;

[0026] Figure 7 A schematic view of a shell with a rough surface on its entire outer surface of a battery cell according to some embodiments of the present application;

[0027] Figures 8 to 11 A schematic view of a shell with a rough surface on part of the outer surface of the side wall and the bottom wall of a battery cell according to some embodiments of the present application;

[0028] Figure 12 A schematic view of a shell with a rough surface on the outer surface of the side wall of a battery cell according to some embodiments of the present application, the roughness of the four corner edges of the side wall increases symmetrically from the four corner edges towards the middle.

[0029] The reference signs in the detailed description of the embodiments are listed as follows:

[0030] Vehicle 1000;

[0031] Battery 100, controller 200, motor 300;

[0032] Box 10, first part 11, second part 12;

[0033] Battery cell 20, end cover 21, electrode terminal 21a, shell 22, electrode assembly 23, tab 23a, liquid bag 24;

[0034] Two smaller side walls 221, 222, bottom wall 223, two larger walls 224, 225, opening 226 of shell 22;

[0035] Two side edge parts 2211, 2212, upper edge part 2213, lower edge part 2214, middle part 2215 of the outer surface of side wall 221;

[0036] Two side edge parts 2231, 2232 and middle part 2233 of bottom wall 223. DETAILED DESCRIPTION

[0037] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments of the present application, and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0039] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly specified and limited.

[0040] Reference herein to "embodiments" means that the particular features, structures, or characteristics described in connection with the embodiments can 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 all refer to the same embodiment, nor is it necessarily a separate or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0041] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0042] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0043] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0044] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0045] At present, from the development of market situation, the application of power battery is more and more extensive. Power battery is not only applied to energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric vehicles, electric transportation tools, military equipment and aerospace and other fields. With the continuous expansion of the application field of power battery, the demand of its market is also increasing.

[0046] For power battery, especially square aluminum shell power battery, with the trend of light and thin design, the thickness of the cell is thinned, and the side area of the cell is also reduced accordingly. This may cause the following problems when the cell needs to be wrapped with an insulating film such as a blue film: the bonding area of the blue film is not enough, the bonding performance is reduced, and the blue film falls off. In addition, at least two power batteries are assembled to form a battery module in the following manner when needed: the power batteries are packaged with the same frame, and they are electrically connected with each other in series, parallel or series-parallel manner and contacted with the outside. At this time, the side plate of the module frame and the side of the cell need to be bonded together by applying structural adhesive. Since the friction coefficient of the aluminum shell is greater than that of the blue film, in order to meet the requirements of vibration and impact test of the battery module, the cell usually adopts U-shaped blue film wrapping, that is, the middle part of the cell side is windowed, that is, the blue film is not wrapped to expose the aluminum shell, but this leads to further reduction of the bonding area of the blue film on the side of the cell, and the blue film wrapped at the bottom of the side is more likely to fall off.

[0047] Based on the above considerations, a battery monomer is proposed, the outer surface of the shell, such as a square aluminum shell, is designed to be at least partially a uniform or non-uniform rough surface, thereby enhancing the bonding force between the cell aluminum shell and the blue film, and / or the aluminum shell and the module side plate.

[0048] The battery monomer disclosed in the embodiments of the present application can be used in, but not limited to, an electric device such as a vehicle, a ship or an aircraft. The power supply system of the electric device can be composed of the battery monomer and the battery disclosed in the present application, so as to alleviate and automatically adjust the deterioration of the cell swelling force, supplement the consumption of electrolyte, and improve the stability of battery performance and the service life of the battery.

[0049] The embodiments of the present application provide an electric device using a battery as a power supply. The electric device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft and the like. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy and an electric aircraft toy, and the like. The spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft, and the like.

[0050] The following embodiments are described with a vehicle 1000 as an example of an electric device of an embodiment of the present application for convenience of description.

[0051] Please refer to Figure 1 , Figure 1 A structural schematic diagram of a vehicle 1000 is provided for some embodiments of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile, or a new energy automobile, which can be a pure electric automobile, a hybrid automobile, or a range extended automobile, etc. The vehicle 1000 is internally provided with a battery 100, which can be arranged at the bottom, head, or tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000, for example, the battery 100 can be used as an operating power supply of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300, the controller 200 being used to control the battery 100 to supply power to the motor 300, for example, for the working power demand of the vehicle 1000 during starting, navigation, and driving.

[0052] In some embodiments of the present application, the battery 100 can not only be used as an operating power supply of the vehicle 1000, but also be used as a driving power supply of the vehicle 1000, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1000.

[0053] Please refer to Figure 2 , Figure 2 An exploded view of the battery 100 is provided for some embodiments of the present application. The battery 100 includes a box body 10 and a battery monomer 20, and the battery monomer 20 is contained in the box body 10. Among them, the box body 10 is used to provide a containing space for the battery monomer 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 can include a first part 11 and a second part 12, the first part 11 and the second part 12 are mutually covered, and the first part 11 and the second part 12 jointly define a containing space for containing the battery monomer 20. The second part 12 can be a hollow structure with one end open, and the first part 11 can be a plate-shaped structure, the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define the containing space; the first part 11 and the second part 12 can also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can be various shapes, such as a cuboid, etc.

[0054] In battery 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, battery 100 can also be composed of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 10. Battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0055] Each battery cell 20 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 to these. The battery cell 20 can be flat, cuboid, or other shapes.

[0056] Please refer to Figure 3 , Figure 3 This is an exploded structural diagram of a battery cell 20 provided in some embodiments of this application. The battery cell 20 refers to the smallest unit that makes up a battery. Figure 3 The battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0057] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. Optionally, end cap 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21 is not easily deformed under pressure and impact, giving battery cell 20 higher structural strength and improved safety performance. Functional components such as electrode terminals 21a can be provided on end cap 21. Electrode terminals 21a can be used for electrical connection with electrode assembly 23 to output or input electrical energy to battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0058] The shell 22 is a component for cooperating with the end cover 21 to form an internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, electrolyte and other components. The shell 22 and the end cover 21 can be independent components, and an opening can be provided on the shell 22, and the end cover 21 is made to cover the opening to form the internal environment of the battery cell 20. Without limitation, the end cover 21 and the shell 22 can also be integrated, specifically, the end cover 21 and the shell 22 can form a common connecting surface before other components enter the shell, and when it is necessary to seal the inside of the shell 22, the end cover 21 is made to cover the shell 22. The shell 22 can be various shapes and sizes, such as a cuboid, etc. Specifically, the shape of the shell 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special limitations thereto.

[0059] The electrode assembly 23 is a component where electrochemical reactions occur in the battery cell 100. One or more electrode assemblies 23 can be contained in the shell 22. The electrode assembly 23 is mainly formed by winding or stacking the positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The positive and negative electrode sheets have a portion with active material constituting the main body of the electrode assembly, and a portion without active material of the positive and negative electrode sheets respectively constituting the tab 23a. The positive and negative tabs can be located together at one end of the main body or at two ends of the main body respectively. In the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tab 23a connects the electrode terminal to form a current loop.

[0060] For the sake of convenience of description and for the sake of clarity, a coordinate system xyz is indicated in the relevant figures. Therein, x denotes the direction along the width, i.e. the lateral direction, y denotes the direction along the length, i.e. the longitudinal direction, and z denotes the direction along the height, i.e. the vertical direction (above the height is referred to as upper / upper portion) and below the height is referred to as lower / lower portion). In the following, the z direction along the height is also referred to as first direction, the x direction along the width is also referred to as second direction, and the y direction along the length is referred to as third direction.

[0061] Therefore, with reference to the above Figure 3 and Figures 4-6 According to some embodiments of the present application, a battery cell 20 is proposed, which comprises at least a shell 22 and at least one electrode assembly 23 arranged inside the shell 22.

[0062] The outer surface of the shell 22, which faces away from the inside of the shell, is at least partially also configured as a uniform or non-uniform rough surface.

[0063] For this purpose, reference can be made, without limitation, Figures 7-12 to the above-mentionedFigure 7 It is shown that the entire outer surface of the case 22 is configured as a rough surface, which here is preferably a uniform rough surface. Non-limitingly, Figure 8 and Figure 9 respectively indicate that part of the outer surface of one of the case side walls 221 located in the xz plane is configured as a rough surface, wherein Figure 8 is that the two opposite side portions 2211, 2212 of the case side wall 221 in the x direction are rough surfaces (indicated in blue), Figure 9 is that the middle portion 2215 other than the aforementioned two side portions is a rough surface (indicated in blue). Figures 10-11 respectively are that the two opposite side portions 2231, 2232 of the bottom wall 223 in the x direction and the middle portion 2233 between the two side portions in the xy plane are configured as rough surfaces (indicated in blue, respectively).

[0064] As mentioned above, a battery cell refers to the smallest unit that constitutes a battery. Its case is a component for fitting an end cover to form the internal environment of the battery cell. The electrode assembly is used to be disposed inside the case and is a component in which electrochemical reactions occur in the battery cell.

[0065] The case interior refers to the internal environment of the battery cell formed for accommodating, for example, the electrode assembly. The case outer surface refers to the outer surface of the case in the opposite direction of the case interior, i.e., the surface of the case that faces away from the case interior.

[0066] A rough surface refers to the surface of an object having a certain roughness. Such a surface has more microscopic unevenness than a smooth surface.

[0067] A uniform or non-uniform rough surface refers to the distribution characteristics of the surface roughness in space. A uniform rough surface refers to a situation in which the roughness parameter (such as the Ra value) remains consistent throughout the surface, i.e., the microscopic geometry of the surface is similar at each location. Conversely, a non-uniform rough surface refers to a situation in which the roughness parameter has different values in different regions of the surface, i.e., the microscopic geometry of the surface varies at different locations. Such a variation can be regular, such as directional variation or regional variation, or random.

[0068] Thus, the outer surface of the case 22 being at least partially configured as a uniform or non-uniform rough surface can be understood as follows: all of its outer surface can be a uniform or non-uniform rough surface; or only part of its outer surface is a rough surface, and the rough outer surface part can be configured to be uniform, i.e., the roughness is consistent, or non-uniform, i.e., the roughness is inconsistent. As mentioned above, regardless of how, the non-uniform rough surface can be a rough surface with random roughness variation or can have directional or regional variation as described below.

[0069] By setting the outer surface of the battery case 22 to be roughened all over or partially, in other words, by increasing the roughness of the roughened outer surface or outer surface portion relative to the original outer surface or the remaining outer surface portion, the adhesion effect of the case, such as an aluminum case, to the insulating film, such as a blue film, to be coated thereon, and the adhesion effect of the side wall of the case, such as an aluminum case, to the side plate of the module, if necessary, can be enhanced.

[0070] According to some embodiments of the present application, the roughness Ra of the roughened surface is in the range of 1 μm to 100 μm. Preferably, Ra is between 1 and 10 μm.

[0071] Roughness is an important parameter for measuring the smoothness of a surface, and the magnitude of the roughness affects various physical properties and functions of an object, and is usually represented by Ra (arithmetic mean height).

[0072] Thus, the surface roughness Ra is an important parameter for measuring the microscopic unevenness of a surface, and is defined as the average deviation of the surface roughness profile from the base (nominal) surface within a sampling length. The measurement method of Ra and related instruments, for example, are mainly as follows:

[0073] Direct contact measurement (stylus method): A stylus-type surface roughness measuring instrument is used, and the up-and-down displacement of the stylus is recorded by moving the stylus along the surface to be measured, and the Ra value is calculated after converting the electrical signal. This method has high precision and is suitable for measuring various roughness, but the measurement speed is relatively slow.

[0074] Non-contact measurement: A non-contact measurement device such as a laser or ultrasonic wave is used, and the surface profile is obtained by irradiating the surface of the measurement member and analyzing the reflected waveform, and the Ra value is calculated. This method can provide accurate roughness values.

[0075] Comparative method: Standard samples (roughness standards) with different roughness levels are used, and the measured surface is compared visually and tactilely or with the aid of a magnifying glass, a comparison microscope, etc., to determine which numerical value the measured surface roughness corresponds to. This method is simple but can be affected by subjective factors, and is suitable for situations where the roughness requirement is not high.

[0076] When selecting a suitable measurement method, factors such as the roughness range of the surface to be measured, the accuracy requirement of the measurement, and the measurement environment need to be considered.

[0077] In addition, a surface having the above-mentioned roughness Ra value can be manufactured, for example, by sanding, sandblasting, knurling, laser etching, chemical etching, heat treatment, or mechanical processing, etc. It can be in the form of a concave-convex pattern or a pattern.

[0078] The roughness Ra of the roughened surface can be selected as appropriate to meet different adhesion strengths between the case and the blue film and / or the side plate of the module.

[0079] According to some embodiments of this application, the housing 22 has a box-shaped structure, such as... Figures 3-4 As shown in Figure 7, it is, for example, a cuboid shape. The shell 22 is open on one side (here, the top) along the z-direction, i.e., the first direction. Figure 4 As can be seen in the upper part, the opening 226 is [the opening]. As mentioned earlier, the opening 226 can be used [for...]. Figure 3 The end cap (also known as the top cap) 21 shown is closed.

[0080] Reference Figure 4 The housing 22 here includes, for example, a first wall opposite to the upper opening 226, corresponding to Figure 5 The bottom wall 223 located in the xy plane is shown; as well as the second wall, third wall, fourth wall, and fifth wall, wherein the second wall and the fourth wall correspond to respectively Figure 4 The two sidewalls 221 and 222 shown are located in the xz plane, and the third and fifth walls correspond to respectively. Figure 4 The diagram shows two walls 224 and 225 located in the yz plane. These walls 221, 222, 224, and 225 are connected end-to-end to each other and connect the opening 226 to the bottom wall 223. In other words, these walls extend between the opening 226 and the bottom wall 223. The third and fifth walls, namely the two walls 224 and 225, are arranged opposite each other along a second direction, i.e., the x direction, which is perpendicular to the first direction, i.e., the z direction. The second and fourth walls, namely the two side walls 221 and 222, are arranged opposite each other along a third direction, i.e., the y direction, which is perpendicular to the first and second directions.

[0081] Advantageously, the dimensions of the two sidewalls 221 and 222 along the x-direction can be smaller than the dimensions of the two walls 224 and 225 along the y-direction. The two sidewalls 221 and 222 can then be referred to as smaller faces, while the two larger walls 224 and 225 adjacent to them in the yz plane can be referred to as larger faces.

[0082] The terms "small surface" and "large surface" are relative, but their functions differ. The smaller surface, referring to sidewalls 221 and 222, may be involved in the connection and fixation of the battery cells. For example, advantageously, the sidewalls 221 and 222 of a square battery casing typically refer to surfaces perpendicular to the large surface; they may be involved in the assembly and fixation of the battery cells, such as walls that are bonded to the side panels of the battery module, located in the xz plane. The larger surface, referring to walls 224 and 225, typically contacts the main body of the battery cell. For example, in a square battery casing, the surface in direct contact with the active material of the battery cell can be considered a large surface.

[0083] The outer surface of the housing 22 therefore includes at least the outer surfaces of the first to fifth walls 221-225.

[0084] For the battery case 22 of the box-shaped structure with the opening 226, the manufacturing and integration are simplified, suitable for automatic production, and for example, it is advantageous for later wrapping of the insulating film such as the blue film, and it is convenient to assemble into a battery module.

[0085] According to some embodiments of the present application, at least part of the outer surface of one or more of the first to fifth walls 221-225 of the case 22 is a rough surface. The rough surface can be a uniform rough surface or a non-uniform rough surface.

[0086] For example, with reference to Figures 8-11 As shown in Figure 8 , the two side portions 2211, 2212 of the outer surface of one of the side walls 221 of the case are configured as rough surfaces (indicated in blue). As shown in Figure 9 , the middle portion 2215 of the outer surface of the side wall 221, other than the two side portions 2211, 2212, is configured as a rough surface (indicated in blue). Advantageously, although not shown in the figure, the entire outer surface of the side wall 221 can be configured as a rough surface.

[0087] Alternatively or additionally, as shown in Figures 10-11 , as previously described, the two side portions 2231, 2232 of the bottom wall 223 and the middle portion 2233 between the two side portions are respectively configured as rough surfaces (indicated in blue, respectively). Alternatively, although not shown in the figure, the entire outer surface of the bottom wall 223 can be configured as a rough surface.

[0088] Of course, this is not limiting. Although not shown in the figure, the outer surface of one or both of the third wall 224 and the fifth wall 225 can also be entirely or partially rough.

[0089] Advantageously, as shown in Figures 4-6 , the abutment portions of the above-mentioned walls of the case 22 and the adjacent walls can be provided in the form of chamfers.

[0090] In other words, that is, any wall 221-225 of the case 22, for example, an aluminum case, any position of any wall, for example, a side portion (a chamfered portion if provided) defined in the x or y direction and a middle portion other than the side portion, or alternatively, an upper portion, a middle portion and a lower portion of the relevant wall distinguished in the z direction, can be configured on the outer surface as a uniform rough surface with a consistent roughness Ra or a non-uniform rough surface with inconsistent roughness Ra.

[0091] The above-mentioned rough surface arrangement can precisely enhance the bonding effect of the aluminum case, here the surface of the aluminum case at the local position, with the blue film behind and / or the aluminum case with the side plate of the module, and can also reduce the processing area of the outer surface of the case.

[0092] Although not shown, according to some embodiments of the application, the outer surfaces of the second and fourth walls, i.e. the two side walls 221, 222, of the housing 22 can all be roughened.

[0093] This arrangement can on the one hand enhance the adhesion of the wrapping blue film to the edge portions of the side walls of the housing 22, preventing the side wall blue film from lifting up at the bottom. On the other hand, it can also enhance the adhesion of the middle portions of the side walls, which are not wrapped by the blue film, to the battery module side plates through structural adhesive, facilitating the later vibration, impact and other tests of the module. Of course, it can also reduce the roughened area.

[0094] According to some embodiments of the application, at least the outer surface side edges of the second and fourth walls, i.e. the two side walls 221, 222, of the housing, which are adjacent to the third and fifth walls, i.e. the walls 224, 225, are roughened.

[0095] For this purpose, reference can still be made to Figure 8 Exemplarily, Figure 8 The outer surface side edges 2211, 2212 of the side wall 221 of the housing are roughened. In a similar manner, although not shown, the corresponding side edges of the outer surface of the other side wall 222 can also be roughened. In the case of the chamfer as described above, the side edges are chamfered, for being wrapped by the blue film thereon.

[0096] Therefore, the outer surface side edges of the side walls 221, 222 here are the left and right edges, e.g. chamfered edges, which are adjacent to the large-surface walls 224, 225.

[0097] In an additional manner, if necessary, the outer surface lower edges, e.g. chamfered edges, of the two side walls 221, 222, which are adjacent to the bottom wall 223, can also be roughened.

[0098] The remaining outer surface portions of the side walls, other than the two side edges and possibly the lower edges, can not need to be roughened.

[0099] By this, the adhesion effect of the wrapping blue film on the edge portions of the aluminum housing side walls can be further precisely enhanced.

[0100] According to some embodiments of the application, the middle portions of the outer surfaces of the second and fourth walls, i.e. the two side walls 221, 222, other than the outer surface side edges adjacent to the third and fifth walls, i.e. the walls 224, 225, are roughened.

[0101] By this, the adhesion of the middle portions of the outer surfaces of the side walls, which are not wrapped by the blue film, to the module side plates through structural adhesive can be precisely enhanced, facilitating the possible vibration, impact and other tests of the module.

[0102] According to some embodiments of the present application, in the case of a non-uniform rough surface, the outer surface of one or more of the first to fifth walls 221-225 of the shell 22 is a rough surface whose roughness varies along a respective one or two of the x, y and z directions.

[0103] By way of non-limiting example, the roughness of the roughened outer surface of one or both of the large walls 224, 225 of the shell 22, such as an aluminum shell, can be arranged to increase along the y direction from one side to the other, for example, as shown in FIG. 5 from left to right. Alternatively, the roughness of the roughened outer surface of the wall 224 can be arranged to increase along the z direction from bottom to top, while increasing along the y direction from left to right. Here, it is not necessary to enumerate all the possibilities. Figure 4

[0104] It is noted that the roughness of a rough surface varies along a particular direction or directions, such as two directions, includes the case where the roughness gradually increases or gradually decreases from one end to the other. This is relative, of course.

[0105] By arranging the roughness of the surface of the shell, such as an aluminum shell, to vary, for example, to increase, in a gradient manner, the adhesion of the aluminum shell to the blue film, and / or possibly to the side plate of the module, can be enhanced precisely, and the processing area of the outer surface of the aluminum shell can be reduced.

[0106] According to some embodiments of the present application, the outer surface of one wall of the first to fifth walls 221-225 of the shell 22 to one or more walls adjacent to the one wall is a rough surface whose roughness varies continuously in a gradient manner from the one wall to the respective adjacent wall.

[0107] By adjacent, it is meant a wall that is adjacent to the relevant wall. For example, for the side walls 221, 222, each is adjacent to two larger walls 224, 225, for example, through a chamfered portion, and is also adjacent to the bottom wall 223. For the large walls 224, 225, each is adjacent to two side walls 221, 222 and the bottom wall 223, for example, through a chamfered portion. For the bottom wall 223, it is adjacent to two side walls 221, 222 and to the two large walls 224, 225, respectively.

[0108] The foregoing arrangement means that the roughness of the roughened outer surface can be arranged to vary continuously in a gradient manner, for example, to increase, between different walls of the shell 22, such as an aluminum shell, although this is not shown in the figures.

[0109] ​For example, the roughness of the outer surface of the bottom wall 223, which is configured to have a rough outer surface, to one or both of the two rough large faces, i.e. walls 224, 225, which are contiguous thereto, is set to correspondingly continuously gradiently increase. Alternatively, the roughness of the outer surface of the side wall 222, which has a rough outer surface, to the two rough large faces, i.e. walls 224, 225, which are contiguous thereto, respectively, and to the rough bottom wall 223, respectively, correspondingly continuously gradiently increase. Here, only a non-exhaustive enumeration is made.

[0110] Such continuously gradiently increasing roughness between different walls can precisely enhance the bonding effect of the aluminum shell to the blue film later.

[0111] According to some embodiments of the present application, each outer surface of one or more of the first to fifth walls 221-225 of the shell is a rough surface whose roughness gradiently increases, preferably symmetrically gradiently increases, from opposite two sides to the middle or from every two opposite four sides to the middle.

[0112] For example Figure 12 The four rough edges of the outer surface of the side wall 221, of which two side edges 2211 and 2212, an upper edge 2213 and a lower edge 2214, are configured to have a roughness that gradiently increases, advantageously symmetrically gradiently increases, from the four edges along the x and z directions to the middle, i.e. from the top and bottom to the middle and from the left and right to the middle (indicated in blue). Alternatively, although not shown, the four rough edges of the outer surface of a wall such as wall 224, which is a large face, can also be configured to have a roughness that gradiently increases, advantageously symmetrically gradiently increases, from the four edges along the y and z directions to the middle, i.e. from the top and bottom to the middle and from the left and right to the middle. Alternatively, although not shown, the roughness of the four rough edges of the bottom wall 223 can also be designed to symmetrically gradiently increase from the four edges along the x and y directions to the middle. Here, only a non-exhaustive enumeration is made.

[0113] Such an arrangement can enhance the pasting effect of the blue film at the edges of the corresponding wall when wrapping the blue film later.

[0114] According to some embodiments of the present application, the corresponding four edges, i.e. the edges along the x and z directions, of the outer surfaces of the second and fourth walls, i.e. the two side walls 221, 222, are rough surfaces whose roughness symmetrically gradiently increases from the four edges to the middle (indicated in blue). As described above, this is, for example, shown in Figure 12 .

[0115] This can precisely enhance the bonding strength of the blue film when wrapping along the edges on the thinner aluminum shell side wall when wrapping the blue film later, preventing the problem of the blue film later being raised at the aluminum shell side, especially at the bottom.

[0116] According to some embodiments of the present application, as mentioned above, the dimensions of the second and fourth walls, i.e. the two side walls 221, 222, along the x direction are smaller than the dimensions of the third and fifth walls, i.e. the walls 224, 225, along the y direction.

[0117] The dimensions of the two side walls 221 and 222 can be smaller than the dimensions of the two walls 224 and 225. The two side walls 221 and 222 are small faces to be bonded to the side plates of the module, and the two larger walls 224 and 225 adjacent thereto are large faces. The roles of the large and small faces have been mentioned above and will not be repeated here.

[0118] The square can structure of the battery is relatively flat, suitable for later wrapping of the blue film, and easy to assemble and transport.

[0119] According to some embodiments of the present application, the present application also provides a battery cell comprising any of the above-mentioned solutions.

[0120] According to some embodiments of the present application, the present application also provides an electrical device comprising any of the above-mentioned batteries, and the battery is used to provide electrical energy for the electrical device.

[0121] The electrical device can be any of the above-mentioned devices or systems to which the battery is applied.

[0122] According to some embodiments of the present application, referring to Figures 3 to 12 , the present application provides a square aluminum shell battery, and the aluminum shell 22 contains at least one electrode assembly 23.

[0123] According to some embodiments of the present application, referring to Figure 7 , the entire outer surface of the shell 22 is provided with a rough surface, i.e. the relative roughness Ra of the entire outer surface is increased to more than 1 μm, even up to 100 μm, compared with the existing aluminum shell with a relative roughness Ra of less than 1 μm. Thus, the adhesion of the aluminum shell to the blue film and possibly to the side plate of the module can be enhanced.

[0124] In addition, according to some embodiments of the present application, referring to Figures 8-11 , the roughness of the outer surface of the battery aluminum shell 22 is designed to be locally increased. For example, in order to solve the problem of the bottom of the side blue film being raised, the roughness of the side of the aluminum shell can be locally increased, but the large face of the aluminum shell remains unchanged. The local position can be any plane of the aluminum shell: the front face, the side face, the bottom face. The local position can be any position of the plane of the aluminum shell: the middle part, the chamfer (which can also be divided into the upper part, the middle part and the lower part of the plane, as long as it can be relatively distinguished). The local position can be any combination of positions of any plane of the aluminum shell (as long as the entire outer surface of the aluminum shell is not uniform in roughness). This enhances the adhesion of the aluminum shell to the blue film and the aluminum shell to the side plate of the module by increasing the roughness of the local position of the surface of the aluminum shell, i.e. it can ensure the improvement of the adhesion, and it can also reduce the processing area of the outer surface of the aluminum shell.

[0125] In addition, according to other embodiments of the present application, as seen in Figure 12 A battery aluminum shell 22 with gradient distribution of roughness on the outer surface of the aluminum shell is also proposed. For example, to solve the problem of the bottom of the side blue film being raised, as seen in Figure 12 The gradient of the roughness on the surface can increase from the top and bottom to the middle, and the gradient of the roughness on the surface can increase from the left and right sides to the middle, but the large surface of the aluminum shell remains unchanged. The gradient design can be applied to any plane (large surface, side surface, bottom surface) and any direction (length direction, width direction, height direction) of the aluminum shell, such as the gradient of the roughness on the outer surface of the aluminum shell changing from left to right in the length direction of the large surface. The gradient design includes symmetric gradient design in a certain direction on the same plane of the aluminum shell, such as Figure 12 The gradient design includes gradient design between different planes of the aluminum shell, such as from the large surface to the side surface, and the gradient roughness design is implemented in the clockwise direction.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application. In particular, each technical feature mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, The battery cell includes: case; At least one electrode assembly is disposed inside the housing; The outer surface of the shell facing away from its interior is at least partially a uniform or non-uniform rough surface.

2. The battery cell as described in claim 1, characterized in that, The roughness Ra of the rough surface is in the range of 1 μm to 100 μm.

3. The battery cell as described in claim 2, characterized in that, The housing has a box-shaped structure, is open on one side along the first direction, and includes at least: The first wall is opposite the opening; The second, third, fourth, and fifth walls are connected end to end to each other and their openings are connected to the first wall. The third and fifth walls are arranged opposite each other along a second direction perpendicular to the first direction, and the second and fourth walls are arranged opposite each other along a third direction perpendicular to the first and second directions. The outer surface of the shell includes at least the outer surfaces of the first to fifth walls.

4. The battery cell as described in claim 3, characterized in that, At least a portion of the outer surface of one or more of the first to fifth walls of the housing is rough.

5. The battery cell as described in claim 4, characterized in that, All outer surfaces of the second and fourth walls of the shell are rough surfaces.

6. The battery cell as described in claim 4, characterized in that, The outer surface sides of the second and fourth walls of the shell, which are respectively adjacent to the third and fifth walls, are rough surfaces.

7. The battery cell as described in claim 4, characterized in that, The middle part of the outer surface of the second and fourth walls, excluding the side portions adjacent to the outer surfaces of the third and fifth walls, is a rough surface.

8. The battery cell as described in claim 4, characterized in that, In the case of a non-uniform rough surface, the outer surfaces of one or more of the first to fifth walls of the housing are rough surfaces with a gradient change in roughness along one or both of the corresponding directions of the first, second, and third directions.

9. The battery cell as described in claim 4, characterized in that, The outer surface of one of the first to fifth walls of the shell, and the adjacent one or more walls, is a rough surface with a continuous gradient of roughness from that wall to the corresponding adjacent wall.

10. The battery cell as described in claim 4, characterized in that, The outer surfaces of one or more of the first to fifth walls of the shell are rough surfaces with a gradient of roughness from opposite sides toward the middle or from four opposite sides toward the middle.

11. The battery cell as described in claim 10, characterized in that, The outer surfaces of the second and fourth walls have corresponding rough edges where the roughness increases symmetrically from the edges toward the center.

12. The battery cell according to any one of claims 3 to 11, characterized in that, The dimensions of the second and fourth walls along the second direction are smaller than the dimensions of the third and fifth walls along the third direction.

13. A battery, characterized in that, The battery includes a battery cell as described in any one of claims 1 to 12.

14. An electrical appliance, characterized in that, The electrical device includes the battery as described in claim 13, the battery being used to provide electrical energy.

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