Single battery and electric device

Abstract

The utility model relates to a single battery and an electric device. The single battery comprises a shell; the battery cell is positioned in the shell; the insulating film at least covers the side surface of the battery cell and is positioned between the battery cell and the shell; the insulating film comprises a plurality of first waveform structures which are arranged at intervals in the first direction; the top edge and / or the bottom edge of the first wave-shaped structure comprises a plurality of second wave-shaped structures which are arranged at intervals in the first direction, the first wave-shaped structure and the second wave-shaped structures extend in the second direction, the first direction intersects with the second direction, and the second direction is the height direction of the single battery. According to the technical scheme, the electrolyte can be attracted from the bottom of the battery cell to the top of the battery cell through capillary acting force, the infiltration effect of the electrolyte is greatly improved while the aluminum shell is prevented from being corroded, the electrochemical performance of the battery is improved, and the cycle life of the battery is prolonged.

Description

Technical Field

[0001] This application relates to the field of lithium battery technology, and in particular to a single cell battery and an electrical device thereof. Background Technology

[0002] Power batteries are rechargeable batteries that provide power to high-energy-consuming devices such as electric vehicles and power tools. Their core characteristics are high energy density, high power output, and long cycle life, making them considered the "heart" of new energy vehicles. To achieve high energy density, most power batteries are lithium-ion batteries. Power batteries are composed of individual cells forming battery modules, battery modules forming battery packs, or individual cells directly forming battery packs.

[0003] A single battery cell consists of an aluminum casing, a cell, and a top cover. During the use of lithium batteries, lithium ions (Li+) at the negative electrode can short-circuit with the aluminum casing due to the flow of electrolyte, causing the lithium ions to embed in the aluminum casing and thus corroding it. Currently, batteries typically use an insulating film structure at the bottom of the cell to prevent aluminum casing corrosion, and staggered holes are used to ensure electrolyte flow. However, the staggered hole structure can affect the cell's electrolyte absorption, thereby affecting the battery's electrochemical performance and cycle life. Utility Model Content

[0004] In view of this, this application provides a single-cell battery and an electrical device to solve at least one problem existing in the prior art.

[0005] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0006] case;

[0007] The battery cell is located inside the housing;

[0008] An insulating film covers at least the side of the cell and is located between the cell and the casing; the insulating film includes a plurality of first waveform structures spaced apart along a first direction; the top edge and / or bottom edge of the first waveform structure includes a plurality of second waveform structures spaced apart along the first direction, wherein both the first waveform structure and the second waveform structure extend along a second direction, the first direction intersects the second direction, and the second direction is the height direction of the single cell.

[0009] In one optional implementation, the first waveform structure and / or the second waveform structure are periodically spaced.

[0010] In one optional embodiment, the first waveform structure includes a first protrusion and a first connecting segment interconnected along the first direction, the first protrusion facing a third-direction protrusion, and the first connecting segment extending along the first direction; the top surface of the first protrusion is configured as the top surface of the first waveform structure, and the first connecting segment is configured as the bottom surface of the first waveform structure, wherein the third-direction, the first direction, and the second direction intersect each other.

[0011] In one optional embodiment, the top surface of the first protrusion is configured as a platform surface, the platform surface having a dimension a along the first direction, the first protrusion having a dimension A along the first direction, where a < 0.5A, and the platform surface having the same dimension along the first direction as the first connecting segment.

[0012] In one optional embodiment, the second waveform structure includes a second protrusion and a second connecting segment that are interconnected in the first direction. The second protrusion faces a third-direction protrusion, and the second connecting segment extends at an angle inclined to the first direction. The shape of the second protrusion is one or more of a triangle, an arc, a trapezoid, a rectangle, and a parallelogram.

[0013] In one optional embodiment, the first protrusion is trapezoidal in shape, and the base angle of the trapezoid is less than 30 degrees.

[0014] In one optional embodiment, the dimension of the second protrusion along the first direction is B, where B < 0.2A.

[0015] In one optional embodiment, the second protrusion is triangular in shape, and the base angle of the triangle is 30 degrees to 80 degrees.

[0016] In one alternative embodiment, the insulating film extends beyond the battery cell along the second direction.

[0017] Secondly, embodiments of this application provide an electrical device, including any of the single-cell batteries described above.

[0018] The single-cell battery and power device provided in this application embodiment include a casing, a cell, and an insulating film. The insulating film includes multiple first waveform structures spaced apart along a first direction, and the top and / or bottom edges of the first waveform structures include multiple second waveform structures spaced apart along the first direction. The insulating film is disposed between the cell and the casing and covers the side of the cell. The two waveform structures of the insulating film can attract the electrolyte from the bottom to the top of the cell through capillary force, which avoids corrosion of the aluminum casing and greatly increases the wetting effect of the electrolyte, thereby improving the electrochemical performance and cycle life of the battery.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0021] Figure 1 A schematic diagram of a single battery cell provided in an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the top cover and insulating film in a single battery cell provided in an embodiment of this application;

[0023] Figure 3 for Figure 2 A schematic diagram of the side projection;

[0024] Figure 4 for Figure 3 A schematic diagram of the projection of an insulating film along direction A;

[0025] Figure 5 for Figure 4 A magnified view of a section at point B (rotated);

[0026] Figure 6 for Figure 5 A magnified view of a portion of point C.

[0027] Explanation of reference numerals in the attached figures:

[0028] 10. Insulating film; 11. First waveform structure; 111. First protrusion; 1111. Platform surface; 1112. Base; 112. First connecting section; 12. Second waveform structure; 121. Second protrusion; 122. Second connecting section; 20. Top cover; 30. Battery cell. Detailed Implementation

[0029] To make the technical solution and beneficial effects of this application more apparent and understandable, a detailed description is provided below by listing specific embodiments. The accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0030] In the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. In other words, they should not be construed as limitations on this application.

[0031] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating the relative importance of the indicated features or the number of indicated technical features. Therefore, a feature specified as "first" or "second" may explicitly include at least one of those features. In the description of this application, "multiple" means at least two, such as two, three, etc.; "several" means at least one, such as one, two, three, etc., unless otherwise explicitly specified.

[0032] In this application, unless otherwise expressly defined, the terms "installation," "connection," "linking," "fixing," "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; 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 also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] In this application, unless otherwise expressly defined, the terms "above," "on top of," "over," "above," "below," "below," "below," or "below" for "first feature over second feature" can refer to the first and second features being in direct contact, or to the first and second features being in indirect contact through an intermediate medium. Furthermore, "above," "over," and "below" for "first feature over second feature" can mean the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than the horizontal height of the second feature. Similarly, "below," "below," and "below" for "first feature over second feature" can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0034] To fully understand this application, detailed steps and structures will be presented in the following description to illustrate the technical solution of this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0035] To address the technical problems in related technologies, embodiments of this application provide a single-cell battery. (Reference) Figures 1-6 The single-cell battery includes a casing, a cell 30, and an insulating film 10. The casing has an opening, the cell 30 is disposed inside the casing, and the insulating film 10 covers at least the side of the cell 30 and is disposed between the cell 30 and the casing. The insulating film 10 includes a plurality of first waveform structures 11 spaced apart along a first direction. The top edge and / or bottom edge of the first waveform structure 11 includes a plurality of second waveform structures 12 spaced apart along the first direction. The first waveform structure 11 and the second waveform structure 12 both extend along a second direction, and the first direction intersects the second direction, which is the height direction of the single-cell battery.

[0036] Understandably, a single battery cell can be rectangular, cylindrical, or other shapes. The casing of the single battery cell contains a cell 30 and an electrolyte. The cell 30 typically includes a positive electrode, a negative electrode, and a separator separating the positive and negative electrodes. The electrolyte can penetrate the interior of the cell 30, providing ion migration pathways for electrochemical reactions and serving a conductive function. The cell 30 can be fabricated by winding, stacking, or other methods. One or more cells 30 can be loaded within a single battery cell. This application primarily uses a single cell 30, a rectangular single battery, and a winding fabrication method as an example. Understandably, the rectangular single battery cell has a rectangular cavity, and the height direction of the cavity is the height direction of the single battery cell.

[0037] Understandably, the first direction is the circumferential direction of the battery cell 30. Multiple first waveform structures 11 are spaced apart along the first direction, forming capillary channels that guide the electrolyte to rapidly penetrate along the extension direction (second direction) of the waveform structure. Furthermore, the first waveform structure 11 increases the surface area of ​​the insulating film 10 in the first direction, thereby increasing its contact area with the electrolyte. This shortens the path for lithium ions to migrate from the electrolyte to the electrode, accelerating electrolyte penetration. As the electrolyte is a heat transfer medium, the increased contact area also allows for faster heat transfer, assisting in heat dissipation of the battery cell 30. Simultaneously, the battery cell 30 undergoes volume expansion during charging and discharging. The first waveform structure 11 has a certain elastic deformation capability, providing a buffer space and reducing stress concentration inside the battery cell.

[0038] Understandably, the second waveform structure 12 is disposed on the top and / or bottom edge of the first waveform structure 11. In other words, the second waveform structure 12 is a small waveform structure within the large waveform structure (first waveform structure 11). That is, the cross-sectional shape of the insulating film 10 includes two waveform structures. The second waveform structure 12 forms capillary channels on the top or bottom edge of the first waveform structure 11. During charging, lithium ions are embedded in the negative electrode of the cell 30, and the increased thickness of the cell 30 causes the single cell to expand, compressing the thickness space of the cell 30. The electrolyte flows from the bottom to the top along the height direction of the single cell. Both the first waveform structure 11 and the second waveform structure 12 extend along a second direction, which is the height direction of the single cell. This facilitates the flow of the electrolyte along the height direction of the single cell through capillary action, thus improving the wettability of the cell 30. Specifically, see... Figure 1 The electrolyte flows upward from the bottom of the cell 30 along with the insulating film 10. At the same time, during the flow, the electrolyte wets the cell 30, and the electrolyte wetted in the cell 30 will also flow downward under the action of gravity, realizing the circulation of the electrolyte and improving the wettability of the cell 30.

[0039] In addition, the single-cell battery also includes a top cover 20, which closes onto the opening of the casing to form a sealed structure. One end of the insulating film 10 abuts against the surface of the top cover 20 facing the cell 30, and micro-channels are formed on the surface of the top cover 20 facing the cell 30. The electrolyte flows upward along the insulating film 10, and after reaching the top cover 20, it flows laterally through the micro-channels of the top cover 20 to the cell 30, increasing the wettability of the top of the cell. The micro-channels can be arranged radially, extending from the center of the top cover to the edge of the top cover, so that the electrolyte spreads more evenly on its surface.

[0040] In this embodiment of the battery, the insulating film 10 is configured as a first waveform structure 11 including multiple protrusions or depressions. The top and / or bottom edges of the first waveform structure 11 include multiple second waveform structures 12 with protrusions or depressions. That is, the insulating film 10 includes two waveform structures. It can attract the electrolyte from the bottom to the top of the cell through capillary force, improving the wettability of the cell 30. At the same time, the waveform structure increases the contact area between the insulating film 10 and the electrolyte, which can accelerate the penetration of the electrolyte and the speed of heat transfer. Moreover, the waveform structure has elastic deformation capability, which can provide buffer space when the battery expands.

[0041] In some embodiments of this application, the first waveform structure 11 and / or the second waveform structure 12 are periodically spaced. That is, they are periodically spaced in the first direction. In this way, the electrolyte flows along the insulating film 10 and is more evenly distributed in the circumferential direction of the cell 30. The spaced arrangement of the two waveform structures can form liquid storage cavities at the top and bottom edges of the insulating film 10, increasing the electrolyte retention inside the cell 30, delaying electrolyte consumption, and extending the cell life.

[0042] In some embodiments of this application, the first waveform structure 11 includes a first protrusion 111 and a first connecting segment 112 interconnected along a first direction. The first protrusion 111 protrudes towards a third direction, and the first connecting segment 112 extends along the first direction. The top surface of the first protrusion 111 is configured as the top surface of the first waveform structure 11, and the first connecting segment 112 is configured as the bottom surface of the first waveform structure 11. The third direction, the first direction, and the second direction intersect each other. Thus, the surface area can be increased through the first protrusion 111, thereby increasing the capillary force. The first connecting segment 112 is configured to connect two adjacent first protrusions 111.

[0043] Specifically, the shape of the first protrusion 111 can be one or more of the following: arc, trapezoid, rectangle and parallelogram. In this way, the insulating film 10 has a space in the third direction that does not contact the battery cell 30, reducing the contact area between the insulating film 10 and the battery cell 30. When foreign objects are present between the insulating film 10 and the battery cell 30, the first protrusion 111 can reduce the risk of foreign objects piercing the battery cell 30.

[0044] In some embodiments of this application, the top surface of the first protrusion 111 is configured as a platform surface 1111, the platform surface 1111 having a dimension 'a' along the first direction, and the first protrusion 111 having a dimension 'A' along the first direction, where a < 0.5A. The dimension of the platform surface 1111 along the first direction is the same as that of the first connecting segment 112. On one hand, the top surface of the first protrusion 111 and the base 1112 have different dimensions in the first direction, such as a trapezoidal shape, which helps increase the surface area of ​​the insulating film 10 in the first direction and improve capillary force. Compared to a platform surface 1111 having a dimension 'a' greater than or equal to the first protrusion 111's dimension 'A', a < A can reduce the amount of material used in the insulating film 10, lower costs, and provide a higher capacity to mitigate expansion. a < 0.5A can reduce the angle between the platform surface 1111 of the first protrusion 111 and the base 1112, increasing the stress release range of the individual electromagnetic components. For example, if the included angle of a trapezoid is too large, the size of the insulating film 10 in the third direction will be too large, wasting battery space. Appropriately extending the waist of the trapezoid and reducing the angle of the two base angles can reduce stress concentration and extend its service life. The longer waist can also increase the contact area between the cell 30 and the electrolyte, promoting electrolyte wetting by increasing capillary force. On the other hand, the size of the platform surface 1111 along the first direction is the same as that of the first connecting segment, i.e., the size of the first connecting segment is 'a'. This ensures the stress balance and stability of the insulating film 10. The consistent size of the two in the first direction reduces the probability of abrupt geometric changes at the intersection of the first protrusion 111 and the first connecting segment 112 when subjected to external force, which would lead to stress concentration. This makes the insulating film 10 form a continuous and smooth structure in the first direction, and the stress can be uniformly transmitted along the first direction. At the same time, it improves the bending stiffness of the insulating film 10 in the third direction. Moreover, the consistent size structure gives the insulating film 10 geometric symmetry, and the electrolyte distribution is more uniform. This keeps the wetting speed basically consistent when flowing in the first direction, improving the performance uniformity of the single cell.

[0045] In some embodiments of this application, the second waveform structure 12 includes second protrusions 121 and second connecting segments 122 interconnected in a first direction. The second protrusions 121 face the third direction, and the second connecting segments 122 extend at an angle inclined to the first direction. The shape of the second protrusions 121 can be one or more of triangles, arcs, trapezoids, rectangles, and parallelograms. This increases the surface area of ​​the insulating film 10 through the second protrusions 121, thereby increasing capillary force and improving the electrolyte wetting effect. The second connecting segments 122 are configured to connect two adjacent second protrusions 121.

[0046] Specifically, the second protrusion 121 is configured as the top surface of the second waveform structure 12, and the second connecting segment 122 is configured as the bottom surface of the second waveform structure 12. The second protrusion 121 and the second connecting segment 122 form a sequential structure of "second protrusion 121-second connecting segment 122-second protrusion 121-second connecting segment 122", which allows stress to be uniformly transmitted along the first direction, avoiding stress concentration that could cause the insulating film 10 to crack or deform.

[0047] In some embodiments of this application, the first protrusion 111 is trapezoidal in shape, with the base angle of the trapezoid being less than 30 degrees.

[0048] Understandably, setting the shape of the first protrusion 111 to a trapezoid can improve the strength of the first waveform structure 11 and reduce manufacturing costs. In some embodiments, the shape of the first protrusion is preferably an isosceles trapezoid, with the base angle of the trapezoid set to less than 30 degrees. This extends the sides of the isosceles trapezoid, reduces the base angle to increase the stress release range, reduces the thickness of the insulating film 10, and improves the group margin of the cell 30. The base angle of the trapezoid is... Figure 5 The middle part is marked as A1.

[0049] In some embodiments of this application, the dimension of the second protrusion 121 along the first direction is B, where B < 0.2A. Thus, multiple second protrusions 121 are distributed within the first protrusion 111, and sufficient second protrusions 121 can further improve the wettability of the battery cell 30. The smaller the dimension B of the second protrusions 121 and the greater their number, the larger the surface area of ​​the insulating film 10, the larger the contact area with the battery cell 30, and the higher the electrolyte wetting efficiency. However, this also increases production costs and manufacturing process difficulty. In some embodiments, the dimension B of the second protrusion 121 is preferably 0.1A-0.15A, which effectively ensures electrolyte wetting while considering production costs and manufacturing process.

[0050] In some embodiments of this application, the second protrusion 121 is triangular in shape, with the base angle of the triangle being 30-80 degrees. Specifically, setting the shape of the second protrusion 121 to a triangle can improve the structural strength of the second waveform structure 12 and reduce manufacturing costs. Setting the base angle of the triangle to 30-80 degrees can further improve the strength of the second waveform structure 12. Figure 6 The middle part is marked as A2.

[0051] In some embodiments of this application, the insulating film 10 extends beyond the battery cell 30 along the second direction. Specifically, in the second direction, one end of the insulating film that abuts against the top cover extends beyond the tab side of the battery cell 30, and the other end of the insulating film extends beyond the side of the battery cell 30 facing away from the tab side. During manufacturing, the edges of the electrode plates of the battery cell 30 may develop burrs, wrinkles, or other problems. The insulating film 10 extending beyond the battery cell 30 and covering the exposed areas of the electrode plate edges can prevent the bare electrodes from contacting adjacent electrodes or the casing, thus avoiding a short circuit in the battery. Furthermore, the insulating film 10 covering the electrode plate edges can also prevent electrolyte leakage and corrosion of the battery casing.

[0052] This application also provides an electrical device, which includes a single battery as described in any of the above embodiments.

[0053] The aforementioned electrical devices can include vehicles, portable electronic devices, electric toys, power tools, energy storage devices, amusement equipment, elevators, and lifting equipment. Vehicles can include automobiles, ships, aircraft, and spacecraft; automobiles can be gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles, with new energy vehicles including pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles; aircraft include airplanes, balloons, and airships; spacecraft include rockets, space shuttles, and spacecraft; portable electronic devices can include mobile phones, laptops, tablets, and digital cameras; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers; energy storage devices can be energy storage walls, base station energy storage, and containerized energy storage; amusement equipment can be carousels, drop towers, etc. This application does not impose any special restrictions on the aforementioned electrical devices.

[0054] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations of the technical solutions contained in this application. Various modifications and changes can be made to the above embodiments without departing from the scope of this application. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of this application that may not be explicitly described. Therefore, the above embodiments merely illustrate several implementations of this application and do not limit the scope of protection of this patent application.

Claims

1. A single-cell battery, characterized in that, include: case; The battery cell is located inside the housing; An insulating film covers at least the side of the cell and is located between the cell and the casing; the insulating film includes a plurality of first waveform structures spaced apart along a first direction; the top edge and / or bottom edge of the first waveform structure includes a plurality of second waveform structures spaced apart along the first direction, wherein both the first waveform structure and the second waveform structure extend along a second direction, the first direction intersects the second direction, and the second direction is the height direction of the single cell.

2. The single-cell battery according to claim 1, characterized in that, The first waveform structure and / or the second waveform structure are periodically spaced.

3. The single-cell battery according to claim 1, characterized in that, The first waveform structure includes a first protrusion and a first connecting segment that are interconnected along the first direction. The first protrusion faces a third-direction protrusion, and the first connecting segment extends along the first direction. The top surface of the first protrusion is configured as the top surface of the first waveform structure, and the first connecting segment is configured as the bottom surface of the first waveform structure. The third-direction, the first direction, and the second direction intersect each other.

4. The single-cell battery according to claim 3, characterized in that, The top surface of the first protrusion is configured as a platform surface, the platform surface having a dimension of a along the first direction, the first protrusion having a dimension of A along the first direction, where a < 0.5A, and the platform surface having the same dimension along the first direction as the first connecting segment.

5. The single-cell battery according to claim 1, characterized in that, The second waveform structure includes a second protrusion and a second connecting segment that are interconnected in the first direction. The second protrusion faces the third-direction protrusion, and the second connecting segment extends at an angle inclined to the first direction. The shape of the second protrusion is one or more of the following: triangle, arc, trapezoid, rectangle, and parallelogram.

6. The single-cell battery according to claim 4, characterized in that, The first protrusion is trapezoidal in shape, and the base angle of the trapezoid is less than 30 degrees.

7. The single-cell battery according to claim 5, characterized in that, The second protrusion has a dimension of B along the first direction, where B < 0.2A.

8. The single-cell battery according to claim 5, characterized in that, The second protrusion is triangular in shape, with the base angle of the triangle being 30-80 degrees.

9. The single-cell battery according to any one of claims 1-8, characterized in that, The insulating film extends beyond the battery cell along the second direction.

10. An electrical device, characterized in that, Includes the single-cell battery as described in any one of claims 1-9.

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