Pole core and battery
By setting a gradient of openings on the electrode, the problems of slow electrolyte wetting speed and poor effect are solved, and the electrolyte is rapidly penetrated and evenly distributed, thereby improving battery performance and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 阿特斯储能科技有限公司
- Filing Date
- 2025-08-01
- Publication Date
- 2026-07-14
Smart Images
Figure CN224501947U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to an electrode core and a battery. Background Technology
[0002] Electrolyte, as a key component of a battery, plays a crucial role in conducting ions between the positive and negative electrodes. It is generally composed of organic solvents, electrolyte salts, and additives. To ensure good electrochemical performance of the battery, the electrolyte must have good wettability to the electrode core.
[0003] In existing batteries, the most common types of electrode cores are stacked cells and wound cells. For wound cells, during electrolyte impregnation, the electrolyte diffuses from the top and bottom of the cell towards the center. For stacked cells, the electrolyte diffuses from the top, bottom, and sides towards the center. This traditional impregnation method allows the electrolyte to penetrate only through the tortuous gaps between particles, resulting in slow impregnation and poor impregnation effect, especially in the central region of the electrode core where electrolyte saturation is low. Furthermore, as the capacity of individual battery cells increases, the electrolyte impregnation effect and impregnation speed become key factors affecting battery performance, influencing lithium battery performance (such as lithium plating, cycle performance, and safety performance) and production efficiency.
[0004] CN 118472569 A discloses an electrolyte wetting method and a battery manufacturing process. The electrolyte wetting method includes the following steps: pre-wetting: vaporizing the electrolyte to obtain vaporized electrolyte, and pre-wetting the battery cell with the vaporized electrolyte; re-wetting: introducing liquid electrolyte to re-wet the pre-wetted battery cell to obtain an injected battery cell. This method can efficiently and quickly circulate the electrolyte throughout the battery casing, accelerating the wetting of electrode pores and separator pores, and effectively solving the problem of poor electrolyte wetting. After completing the pre-wetting of the battery, injecting liquid electrolyte for re-wetting can greatly reduce the electrolyte wetting time.
[0005] CN 114171801 A discloses a method for electrolyte impregnation of a soft-pack battery cell. The method includes: (1) encapsulating the cell and reserving an injection port, such that the angle between the side of the cell containing the injection port and the horizontal plane is θ1, where 0° < θ1 < 90°; evacuating and injecting electrolyte, so that the electrolyte impregnates the cell from bottom to top; and (2) rotating the cell after electrolyte injection. This method greatly shortens the time required for electrolyte impregnation, achieves rapid impregnation of lithium-ion battery cells, eliminates the influence of high temperature on electrolyte composition, and improves the impregnation effect. Furthermore, this method eliminates the need for repeated vacuuming and rolling, reducing production energy consumption while improving production efficiency.
[0006] However, the above technologies are all improvements to the wetting method but do not optimize the structure of the electrode core, resulting in cumbersome operation.
[0007] Therefore, there is an urgent need to design an electrode core to improve the electrolyte wetting effect and wetting speed, and ensure that the battery has good electrochemical performance. Utility Model Content
[0008] In view of the above-mentioned technical problems existing in the prior art, the purpose of this utility model is to provide an electrode core and a battery.
[0009] To achieve the above objectives, the present invention adopts the following technical solution:
[0010] In a first aspect, the present invention provides an electrode core, the electrode core including an electrode sheet and a separator, the electrode sheet including a positive electrode sheet and a negative electrode sheet, the separator being located between the positive electrode sheet and the negative electrode sheet, the electrode sheet having openings, and the opening density gradient of the electrode sheet increasing from the inner side to the outer side of the electrode core, and the opening diameter gradient of the electrode sheet decreasing.
[0011] This invention involves creating openings in the electrode sheet and controlling the direction from the inside to the outside of the electrode core. The opening density gradient of the electrode sheet increases while the opening diameter gradient decreases. This not only increases the wetting path of the electrolyte from the outside to the inside, forming a capillary network and driving the electrolyte to penetrate quickly, but also ensures the strength of the electrode sheet, thereby ensuring that the electrode core has good strength.
[0012] Preferably, the direction from the inner side to the outer side of the electrode core is denoted as the first direction. The shapes of the openings are successively inverted conical, cylindrical, and conical, wherein the inverted conical opening has a larger diameter along the first direction, the cylindrical opening has a constant diameter along the first direction, and the conical opening has a smaller diameter along the first direction. Near the inner side of the electrode core, the opening shape of the electrode sheet is inverted conical, which facilitates the directional discharge of gas; between the inner and outer sides of the electrode core, the opening shape of the electrode sheet is cylindrical; and on the outer side of the electrode core, the opening shape of the electrode sheet is conical, which facilitates the directional and accelerated penetration of electrolyte, thereby improving the wetting effect.
[0013] The present invention improves the wetting performance of the electrode core, greatly shortens the wetting time, and significantly improves the uniformity of electrolyte saturation distribution in the electrode core.
[0014] In this invention, for inverted cone and cone shapes, the aperture diameter refers to the diameter of its largest cross-section.
[0015] Preferably, the gradient increment is divided into at least 3 gradients. For example, the number of gradients can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, etc.; the gradient decrement is divided into at least 3 gradients. For example, the number of gradients can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, etc.
[0016] More preferably, the gradient increase is divided into 5 to 10 gradients, and the gradient decrease is divided into 5 to 10 gradients.
[0017] Preferably, the difference in pore density between adjacent electrodes is 3 to 8 pores / cm². 2 For example, it could be 3 per cm 2 4 per cm 2 5 pieces / cm 2 6 pieces / cm 2 7 per cm 2 Or 8 per cm 2 wait.
[0018] Preferably, the difference in aperture between adjacent electrodes is 3 to 8 μm, for example, it can be 3 μm, 4 μm, 5 μm, 6 μm, 7 μm or 8 μm.
[0019] Preferably, the aperture density of the electrode is 5 to 40 apertures / cm². 2 Within a range, for example, it could be 5 per cm. 2 7 per cm 2 10 pieces / cm 2 12 pieces / cm 2 14 pieces / cm 2 16 pieces / cm 2 18 pieces / cm 2 20 pieces / cm 2 23 pieces / cm 2 25 pieces / cm 2 28 pieces / cm 2 30 pieces / cm 2 33 pieces / cm 2 35 pieces / cm 2 37 pieces / cm 2 38 pieces / cm 2 Or 40 pieces / cm 2 Etc. The aperture density here refers to the aperture density on a single electrode.
[0020] Preferably, the aperture of the electrode is in the range of 15 to 50 μm, for example, it can be 15 μm, 17 μm, 18 μm, 20 μm, 22 μm, 23 μm, 25 μm, 28 μm, 30 μm, 33 μm, 35 μm, 36 μm, 38 μm, 40 μm, 43 μm, 46 μm, 48 μm or 50 μm.
[0021] This utility model does not specifically limit the type of electrode core. For example, the electrode core is a laminated cell or a wound cell.
[0022] Preferably, the electrode core includes an electrode sheet and a separator, the electrode sheet includes a positive electrode sheet and a negative electrode sheet, and the separator is located between the positive electrode sheet and the negative electrode sheet.
[0023] In this invention, the method for opening holes in the electrode sheet can be a method disclosed in the prior art, such as laser micro-hole technology.
[0024] Secondly, this utility model provides a battery, which includes a battery casing, an electrode core, and an electrolyte, wherein the electrode core is the electrode core described in the first aspect.
[0025] Compared with existing technologies, this utility model has the following beneficial effects:
[0026] This invention involves creating openings in the electrode sheet and controlling the direction from the inside to the outside of the electrode core. The opening density gradient of the electrode sheet increases while the opening diameter gradient decreases. This not only increases the wetting path of the electrolyte from the outside to the inside, forming a capillary network and driving the electrolyte to penetrate quickly, but also ensures the strength of the electrode sheet, thereby ensuring that the electrode core has good strength.
[0027] The present invention improves the wetting performance of the electrode core, greatly shortens the wetting time, and significantly improves the uniformity of electrolyte saturation distribution in the electrode core. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of a portion of the electrode sheet in one embodiment of the present invention.
[0029] Figure 2 This is a schematic diagram of a portion of the electrode sheet in one embodiment of the present invention.
[0030] Figure 3 This is a schematic diagram of the structure of a wound battery cell.
[0031] Figure 4 This is a schematic diagram of the structure of a laminated battery cell.
[0032] In the diagram, 1 is the electrode, 11 is the foil, 12 is the active material coating, A is the cylindrical hole, and B is the inverted conical hole. Detailed Implementation
[0033] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this utility model are shown in the drawings, not all of them.
[0034] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can 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 utility model based on the specific circumstances.
[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0036] In the description of the embodiments disclosed herein, the terms "upper," "lower," "left," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings, and are used only for ease of description and simplification of operation. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are merely used for distinction in description and have no special meaning.
[0037] In the following embodiments, see Figure 1 and Figure 2 The electrode 1 includes a foil 11 and an active material coating 12 disposed on both sides of the foil. When the electrode is a positive electrode, the foil 11 is an aluminum foil and the active material coating 12 is a positive active material layer; when the electrode is a negative electrode, the foil 11 is a copper foil and the active material coating 12 is a negative active material layer.
[0038] In this invention, the active material layer is a coating that has been disclosed in the prior art, and its preparation method is a known method. For example, an electrode slurry can be obtained by uniformly mixing the active material, binder and optional conductive agent in a solvent, coating the electrode slurry on both sides of the foil, and drying it to form an active material coating on the surface of the foil.
[0039] Example 1
[0040] This embodiment provides an electrode core, which includes electrode sheets and a separator. The electrode sheets include positive and negative electrode sheets, and the separator is located between the positive and negative electrode sheets. The electrode sheets have openings, and the openings of each turn of the electrode sheet are evenly distributed on that layer of electrode sheets. The electrode core is a wound battery cell. See [link to relevant documentation]. Figure 3 The electrode core contains a total of 45 coils of electrodes. Figure 3 (Not all are shown in the table). The innermost electrode is the 1st ring, and the outermost electrode is the 45th ring. The aperture density, aperture diameter, and aperture shape of each ring of electrode are shown in Table 1. The direction from the inner side of the electrode core to the outer side of the electrode core is denoted as the first direction. The aperture shape is sequentially an inverted cone shape (see Table 1). Figure 2 B) Cylindrical (see B) Figure 2 In the first direction, A) and the conical shape, wherein the inverted conical shape has a larger aperture along the first direction, the cylindrical shape has a constant aperture along the first direction, and the conical shape has a smaller aperture along the first direction.
[0041] Table 1
[0042]
[0043] Example 2
[0044] This embodiment provides an electrode core, which includes an electrode sheet and a separator. The electrode sheet includes a positive electrode sheet and a negative electrode sheet. The separator is located between the positive electrode sheet and the negative electrode sheet. The electrode sheet has openings, and the openings of each electrode sheet are evenly distributed on the electrode sheet.
[0045] The electrode core is a laminated cell, see [link / reference] Figure 4 The electrode core contains a total of 39 layers of electrodes. Figure 4 (Not all are shown in the table). The innermost electrode is the first layer, and the second layer is on both sides of the first layer electrode, and so on. The outermost electrode is the 39th layer. The aperture density, aperture diameter and aperture shape of each layer of electrode are shown in Table 1. The direction from the inner side of the electrode core to the outer side of the electrode core is called the first direction. The aperture shapes are inverted cone, cylindrical and conical in sequence. The inverted cone has an aperture that increases along the first direction, the cylindrical has an aperture that remains unchanged along the first direction, and the conical has an aperture that decreases along the first direction.
[0046] Table 2
[0047]
[0048] Example 3
[0049] The difference from Example 1 is that the openings in each layer are all cylindrical.
[0050] Example 4
[0051] The difference from Example 1 lies in the aperture density, aperture diameter, and aperture shape of each electrode layer, as shown in Table 3.
[0052] Table 3
[0053]
[0054] Comparative Example 1
[0055] The difference from Example 1 is that the aperture density of each electrode is 5 apertures / cm². 2 The aperture diameter of each electrode is 50μm.
[0056] Assemble the battery:
[0057] The electrode cores of Examples 1-4 and Comparative Example 1 were placed into a battery casing, and electrolyte was injected. The casing was then sealed to obtain a battery.
[0058] Wetting performance test: The electrode core is placed in the electrolyte for wetting performance test. The vertical distance from the surface of the electrode sheet in the electrode core to the center of the electrode core is denoted as 'a'. 'a' is divided into three equal parts. The area corresponding to the third part closest to the center is the central area. The area corresponding to the third part closest to the electrode sheet surface is the edge area. The area between the central area and the edge area is the transition area. The wetting performance of the central area, the transition area and the edge area is observed and recorded as excellent, good or poor.
[0059] The results are shown in Table 4.
[0060] Table 4
[0061]
[0062] As shown in Table 4, the electrode core of this invention has good wetting performance, and compared with Comparative Example 1, it is beneficial to reduce the interfacial impedance of the electrode / electrolyte and improve cycle life and rate performance.
[0063] Meanwhile, a comparison between Example 1 and Example 3 shows that, from the inner side of the electrode core to the outer side of the electrode core, the shapes of the openings are successively inverted cone, cylindrical and conical, which is beneficial to improving the wetting performance.
[0064] A comparison between Example 1 and Example 4 shows that controlling the difference in pore density and pore diameter between adjacent electrode layers within a suitable range is more conducive to improving wetting performance within the preferred range.
[0065] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. An electrode core, characterized in that, The electrode core includes an electrode sheet and a separator. The electrode sheet includes a positive electrode sheet and a negative electrode sheet. The separator is located between the positive electrode sheet and the negative electrode sheet. The electrode sheet has openings. From the inside of the electrode core to the outside of the electrode core, the opening density gradient of the electrode sheet increases and the opening diameter gradient of the electrode sheet decreases.
2. The electrode core according to claim 1, characterized in that, The direction from the inside of the electrode core to the outside of the electrode core is denoted as the first direction. The shapes of the openings are, in sequence, inverted cone, cylindrical and conical. The inverted cone has a larger aperture along the first direction, the cylindrical has a constant aperture along the first direction, and the conical has a smaller aperture along the first direction.
3. The electrode core according to claim 1 or 2, characterized in that, The gradient increment is divided into at least 3 gradients, and the gradient decrement is divided into at least 3 gradients.
4. The electrode core according to claim 3, characterized in that, The gradient increment is divided into 5 to 10 gradients, and the gradient decrement is divided into 5 to 10 gradients.
5. The electrode core according to claim 1 or 2, characterized in that, The difference in pore density between adjacent electrodes is 3–8 pores / cm². 2 .
6. The electrode core according to claim 1 or 2, characterized in that, The difference in aperture between adjacent electrodes is 3–8 μm.
7. The electrode core according to claim 1 or 2, characterized in that, The aperture density of the electrode is 5 to 40 apertures / cm². 2 Within the range.
8. The electrode core according to claim 1 or 2, characterized in that, The aperture of the electrode is in the range of 15 to 50 μm.
9. The electrode core according to claim 1 or 2, characterized in that, The electrode core is a laminated cell or a wound cell.
10. A battery, characterized in that, The battery includes a battery casing, an electrode core, and an electrolyte, wherein the electrode core is the electrode core as described in any one of claims 1-9.