Battery cell structure, battery and electric equipment
By setting up compensation parts on the outer surface of the bare core body, the problem of uneven thickness when the bare core is transformed into hot pressing is solved, and the service life of the bare core is extended.
Patent Information
- Application Number
- CN202422399456.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2034-09-30
AI Technical Summary
When the bare battery is heated into hot pressing, the thickness of the electrode ears is uneven, resulting in uneven stress, which makes it easy to decompose lithium and the electrode sheet and the diaphragm poorly bond, shorten the service life.
Compensation parts are provided on the outer surface of the main body of the bare core. The compensation parts melt and flow to uneven thickness during hot pressing, and solidify after cooling, improving the problem of uneven thickness and extending service life.
Through the flow and solidification of the compensation parts, the thickness uniformity of the bare cell is improved and the service life of the bare cell is extended.
Smart Images
Figure CN223296874U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a battery core structure, a battery and electrical equipment. Background Art
[0002] Generally, a bare cell is formed by winding a stacked positive electrode sheet, a separator, and a negative electrode sheet, and both the positive and negative electrode sheets are welded with tabs. The presence of the tabs makes the thickness of the bare cell uneven during hot pressing, that is, the thickness of the part of the bare cell corresponding to the tab is greater than the thickness of the rest of the bare cell. As a result, the bare cell is subjected to uneven force during formation. The part of the bare cell corresponding to the tab will be subjected to excessive force and there is a risk of lithium plating, while the rest of the bare cell is subjected to less force, which can easily lead to poor adhesion between the electrode and the separator, resulting in cycle deformation and ultimately cycle failure, greatly shortening the service life of the bare cell. Utility Model Content
[0003] The purpose of the present invention is to provide a battery cell structure, a battery and an electrical device, aiming to solve the technical problem of short service life of bare battery cells in the related art.
[0004] In the first aspect, the present application provides a battery cell structure, which includes a bare battery cell and a compensation part. The bare battery cell includes a main body and a pole ear connected to the main body, at least part of the pole ear is located inside the main body, and the main body has two opposite outer surfaces in its own thickness direction, each outer surface has a pole ear area corresponding to the pole ear, and the compensation part is arranged on at least one outer surface and covers the pole ear area. The compensation part is configured to melt after being heated and solidify after being cooled.
[0005] The beneficial effect of the battery cell structure provided by the present invention is as follows: in the related art, when the bare battery cell is formed and hot-pressed, the part of the bare battery cell corresponding to the pole ear is raised to form a bulge. At this time, the thickness of the bare battery cell is uneven, which greatly shortens its service life. In this battery cell structure, when the bare battery cell is formed and hot-pressed, the hot pressing equipment will transfer heat to the compensating part, causing the compensating part to melt into a liquid with fluidity. The liquid in the pole ear area flows to the rest of the bare battery cell, that is, outside the pole ear area, under the pressure of the hot pressing equipment. After cooling, the compensating part solidifies and solidifies. In this way, the problem of uneven thickness of the bare battery cell can be improved, thereby extending the service life of the bare battery cell.
[0006] Optionally, the main body includes a straight section and an arc section, the straight section is connected to arc sections on both sides, the tabs are located in the straight section, and in the width direction of the straight section, the two ends of the compensation piece extend to the two side edges of the straight section respectively.
[0007] Optionally, in the length direction of the straight section, both ends of the compensation piece extend to both side edges of the straight section respectively.
[0008] Optionally, the compensating member includes a base layer and an adhesive layer, wherein the adhesive layer is arranged on a side of the base layer close to the outer surface, and the melting point of the adhesive layer is lower than the melting point of the base layer.
[0009] Optionally, the melting point of the adhesive layer is 50°C to 120°C.
[0010] Optionally, the thickness of the adhesive layer is 10 micrometers to 100 micrometers.
[0011] Optionally, the thickness of the base layer is 2 micrometers to 30 micrometers.
[0012] Optionally, the material of the adhesive layer is one of water-based adhesive, oil-based adhesive, hot-melt adhesive, natural rubber and synthetic rubber.
[0013] Optionally, the material of the base layer is one of CPP, OPP, BOPP, PE, PET, PVC and MOPP.
[0014] In a second aspect, the present application provides a battery comprising the above-mentioned battery cell structure.
[0015] In a third aspect, the present application provides an electrical device comprising the above-mentioned battery. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0017] Figure 1 Schematic diagram of the structure of a bare battery cell before and after forming and hot pressing in the related art;
[0018] Figure 2 A schematic diagram of the structure of the battery cell provided in an embodiment of the present utility model before and after forming and hot pressing;
[0019] Figure 3 for Figure 2 A magnified view of middle A;
[0020] Figure 4 Another structural schematic diagram of a battery cell structure provided by an embodiment of the present utility model;
[0021] Figure 5 This is a test diagram of the cycle performance of the battery cell structure provided by an embodiment of the present utility model at 25°C (normal temperature);
[0022] Figure 6 This is a test diagram of the cycle performance of the battery cell structure provided in an embodiment of the present utility model at 45°C.
[0023] Among them, the reference numerals in the figures are:
[0024] 100. Cell structure; 10. Bare cell; 20. Compensation component;
[0025] 11. Main body; 12. Tab; 111. Straight section;
[0026] 112. arc segment; 1111. outer surface; 1112. tab area;
[0027] 21. Base layer; 22. Adhesive layer; 200. Raised part. DETAILED DESCRIPTION
[0028] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.
[0029] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, when the phrases "in one embodiment" or "in some embodiments" appear in various places throughout this specification, not all references are to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0030] In the description of the present invention, 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 accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.
[0032] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, indirect connection through an intermediate medium, internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.
[0033] Please refer to Figures 1 to 6 Now, the battery cell structure 100, battery and electrical equipment in the embodiment of the present invention are described.
[0034] Please refer to Figures 2 to 4 The battery cell structure 100 provided in the present application includes a bare battery cell 10 and a compensation member 20. The bare battery cell 10 includes a main body 11 and a tab 12 connected to the main body 11. At least part of the tab 12 is located in the main body 11. The main body 11 has two opposite outer surfaces 1111 in its own thickness direction. Each outer surface 1111 has a tab area 1112 corresponding to the tab 12. The compensation member 20 is arranged on at least one outer surface 1111 and covers the tab area 1112. The compensation member 20 is configured to melt after being heated and solidify after being cooled.
[0035] In related technologies, please combine Figure 1 When the bare cell 10 is hot-pressed, the portion of the bare cell 10 corresponding to the tab 12 is raised to form a raised portion 200. At this time, the thickness of the bare cell 10 is uneven, which greatly shortens its service life. In this cell structure 100, please combine Figure 2 During the hot pressing of the bare cell 10, the heat is transferred to the compensating member 20, causing it to melt into a fluid liquid. Under the pressure of the hot pressing device, the liquid in the tab region 1112 flows to the rest of the bare cell 10, i.e., outside the tab region 1112. After cooling, the compensating member 20 solidifies. This improves the uneven thickness of the bare cell 10, thereby extending the service life of the bare cell 10.
[0036] Preferably, compensation members 20 are provided on both outer surfaces 1111 to improve the problem of uneven thickness of the bare battery cell 10 to a greater extent.
[0037] It should be noted that the compensating member 20 is more suitable for thinner bare cells 10, such as those used in Bluetooth headset charging cases and watches. Because the width of the tab 12 in these bare cells 10 accounts for 20% to 40% or even more of the width of the bare cell 10, the compensating member 20 can better address the uneven thickness of the bare cell 10. Of course, the compensating member 20 can also be used with other types of bare cells 10, without limitation.
[0038] In another embodiment of this application, please refer to Figures 2 to 4 The main body 11 includes a straight section 111 and an arc section 112. The arc sections 112 are connected to opposite sides of the straight section 111. The tabs 12 are located in the straight section 111. In the width direction of the straight section 111, the two ends of the compensating member 20 extend to the edges of the straight section 111. Specifically, the straight section 111 has an outer surface 1111, and there are two arc sections 112. The two arc sections 112 are located on opposite sides of the straight section 111. It can be understood that the bare cell 10 is formed by winding the positive electrode sheet, the separator, and the negative electrode sheet in sequence along its head. Each layer of electrode sheet has a corresponding straight section 111 and at least one arc section 112. From the winding center of the bare cell 10 to the outside, the straight sections 111 and arc sections 112 of the multiple layers of electrode sheets are stacked in sequence to form the straight section 111 of the bare cell 10 and two arc sections 112 of the bare cell 10. By configuring the compensating member 20 to cover both side edges of the straight section 111 in the thickness direction, the improvement degree of the bare cell 10 by the compensating member 20 can be increased, thereby further extending the service life of the bare cell 10 .
[0039] In another embodiment of this application, please refer to Figure 4 In the length direction of the straight section 111, the two ends of the compensating member 20 extend to the two side edges of the straight section 111. This arrangement can improve the improvement degree of the bare cell 10 by the compensating member 20, thereby further extending the service life of the bare cell 10.
[0040] It should be noted that in Figure 4 In the figure, in order to better illustrate the figure number, the compensation part 20 is shown as smaller than the outer surface 1111.
[0041] In another embodiment of the present application, the compensation member 20 covers the entire outer surface 1111 , which can improve the problem of uneven thickness of the bare battery cell 10 to the greatest extent.
[0042] In another embodiment of this application, please refer to Figure 1The compensating member 20 includes a base layer 21 and an adhesive layer 22. The adhesive layer 22 is disposed on the side of the base layer 21 close to the outer surface 1111. The adhesive layer 22 has a lower melting point than the base layer 21 and is bonded to the outer surface 1111. This arrangement ensures that the adhesive layer 22 melts while the base layer 21 does not. This prevents the adhesive layer 22 from sticking to the hot pressing equipment after the base layer 21 melts, thereby reducing the improvement effect of the compensating member 20 on the bare battery cell 10.
[0043] In another embodiment of this application, please refer to Figure 1 , the melting point of the adhesive layer 22 is 50°C to 120°C. As an example, the melting point of the adhesive layer 22 can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C or a range between any two of the aforementioned values. Controlling the melting point of the adhesive layer 22 within the above range, on the one hand, prevents the melting point of the adhesive layer 22 from being too low, causing the adhesive layer 22 to melt during transportation or storage of the compensation part 20. On the other hand, preventing the melting point of the adhesive layer 22 from being too high can reduce the energy consumption of the hot pressing equipment. In addition, the higher the melting point of the adhesive layer 22, the higher the temperature of the hot pressing equipment. In this way, the bare battery cell 10 will be affected by the high temperature, resulting in a decrease in the performance of the bare battery cell 10.
[0044] In another embodiment of this application, please refer to Figure 1 The thickness of the adhesive layer 22 is between 10 and 100 microns. For example, the thickness of the adhesive layer 22 can be 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 microns, or a range between any two of the aforementioned values. By controlling the thickness of the adhesive layer 22 within the aforementioned range, the overall thickness of the compensating member 20 can be reduced while still ensuring that the uneven thickness of the bare battery cells 10 is improved, thereby minimizing the impact on the battery's energy density.
[0045] In another embodiment of this application, please refer to Figure 1 The thickness of the base layer 21 is between 2 and 30 microns. For example, the thickness of the base layer 21 can be 2, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, or 30 microns, or a range between any two of the aforementioned values. By controlling the thickness of the base layer 21 within the aforementioned range, the overall thickness of the compensating element 20 can be reduced, thereby minimizing the impact on the battery's energy density.
[0046] In another embodiment of the present application, the material of the adhesive layer 22 is one of water-based adhesive, oil-based adhesive, hot melt adhesive, natural rubber and synthetic rubber.
[0047] In another embodiment of the present application, the material of the base layer 21 is one of CPP, OPP, BOPP, PE, PET, PVC and MOPP.
[0048] In another embodiment of this application, please refer to Figure 1 , on the same outer surface 1111, the thickness of the adhesive layer 22 located at the raised portion 200 is H1, and the thickness of the adhesive layer 22 located at the remaining positions is H2, satisfying the relationship: 0.03H2≤H1≤0.4H2. It can be understood that the adhesive layer 22 at the remaining positions refers to the adhesive layer 22 located at positions other than the raised portion 200 on the same outer surface 1111. The present battery cell structure 100 has two states, one of which is the first state before the bare cell 10 is formed and hot-pressed. At this time, the compensation member 20 is flatly arranged on the outer surface 1111 of the straight section 111. The other is the second state after the bare cell 10 is formed and hot-pressed. At this time, the compensation member 20 has been deformed, specifically, at least part of the adhesive layer 22 located at the tab area 1112 moves outside the tab area 1112 to increase the thickness of the thinner portion of the bare cell 10. In the second state, the relationship: 0.03H2≤H1≤0.4H2 is satisfied. In this way, the flatness of the bare cell 10 can be improved, and the overall thickness of the bare cell 10 can be made uniform.
[0049] Please refer to Figure 5 and Figure 6 , wherein the normal temperature cycle test and the 45°C cycle test are both tested with the following battery cell structure 100, the battery cell structure 100 is: both outer surfaces 1111 are provided with compensation members 20, and the compensation members 20 completely cover the corresponding outer surfaces 1111. Figure 5 and Figure 6 It can be seen that compared with the bare battery cell 10 in the related art, the capacity retention rate of the bare battery cell 10 is significantly improved in a long cycle period (for example, 500 cycles), effectively extending the service life of the bare battery cell 10.
[0050] The present application also provides a battery, which includes the above-mentioned battery cell structure 100. Since the battery uses the above-mentioned battery cell structure 100, the service life of the battery is effectively extended.
[0051] The battery can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel metal hydride battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.
[0052] The present application also provides an electrical device comprising the aforementioned battery. The electrical device may include, but is not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, battery-powered vehicles, electric cars, ships, spacecraft, and the like. The electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the spacecraft may include airplanes, rockets, space shuttles, and spacecraft, among others.
[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A battery cell structure, characterized in that: include: A bare battery cell (10) comprises a main body (11) and a tab (12) connected to the main body (11), wherein at least a portion of the tab (12) is located within the main body (11), and the main body (11) has two opposite outer surfaces (1111) in its thickness direction, and each outer surface (1111) has a tab region (1112) corresponding to the tab (12); A compensating member (20) is provided on at least one of the outer surfaces (1111) and covers the tab region (1112); the compensating member (20) is configured to melt when heated and solidify when cooled.
2. The battery cell structure according to claim 1, wherein: The main body (11) comprises a straight section (111) and an arc section (112), the arc sections (112) are connected to opposite sides of the straight section (111), and the tab (12) is located in the straight section (111); wherein, In the width direction of the straight section (111), both ends of the compensating member (20) extend to the two side edges of the straight section (111); and / or, In the length direction of the straight section (111), both ends of the compensation piece (20) extend to the two side edges of the straight section (111) respectively.
3. The battery cell structure according to claim 1, wherein: The compensating member (20) comprises a base layer (21) and an adhesive layer (22), wherein the adhesive layer (22) is arranged on a side of the base layer (21) close to the outer surface (1111), and the melting point of the adhesive layer (22) is lower than the melting point of the base layer (21).
4. The battery cell structure according to claim 3, wherein: The melting point of the adhesive layer (22) is 50°C to 120°C.
5. The battery cell structure according to claim 3, wherein: The thickness of the adhesive layer (22) is 10 micrometers to 100 micrometers.
6. The battery cell structure according to claim 3, wherein: The thickness of the base layer (21) is 2 microns to 30 microns.
7. The battery cell structure according to claim 3, characterized in that: The material of the adhesive layer (22) is one of water-based adhesive, oil-based adhesive, hot-melt adhesive, natural rubber and synthetic rubber.
8. The battery cell structure according to claim 3, wherein: The material of the base layer (21) is one of CPP, OPP, BOPP, PE, PET, PVC and MOPP.
9. A battery, characterized in that: The battery cell structure (100) comprises the battery cell structure (100) according to any one of claims 1 to 8.
10. An electrical device, characterized in that: A battery comprising the battery of claim 9.