Pole piece assembly and battery
By designing a bent structure for the cathode and anode plates of the electrode assembly, the problems of negative electrode expansion in wound cells and low fabrication efficiency of stacked cells were solved, achieving high energy density and high-efficiency battery modules and reducing processing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG LIWINON ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-05-28
- Publication Date
- 2026-07-14
AI Technical Summary
In existing technologies, when the energy density of wound cells is increased by increasing the silicon content, the negative electrode expands to a large volume, resulting in significant corner disadvantages and low space utilization. While stacked cells have high energy density, their manufacturing efficiency is low and the cost is high, making it difficult to apply on a large scale.
Design an electrode assembly in which the cathode sheet has a bending portion that can be bent relative to the anode sheet, allowing the cathode current collector and anode current collector to be stacked. The anode sheet can also be bent relative to the cathode sheet, avoiding corner problems and eliminating the need for electrode cutting steps, combining the advantages of wound and stacked cells.
It improves the space utilization and manufacturing efficiency of the battery cell, takes into account the battery energy density, reduces processing costs, and avoids excessive expansion volume of the negative electrode and the disadvantage of corners.
Smart Images
Figure CN224502255U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to an electrode assembly and a battery. Background Technology
[0002] With the development of the new energy industry, the market demand for battery energy density is increasing. Current technologies improve battery energy density by increasing the silicon content. However, for wound cells, a higher silicon content leads to a larger negative electrode expansion volume, making the corner disadvantages of wound cells more pronounced and reducing space utilization. While stacked cells offer higher energy density and eliminate corner issues, their manufacturing efficiency is lower, requiring die-cutting molds, resulting in higher costs and hindering large-scale application. Utility Model Content
[0003] The main purpose of this invention is to propose an electrode assembly and a battery, which aims to solve the technical problem of low cell manufacturing efficiency.
[0004] To achieve the above objectives, a first aspect of this utility model provides an electrode assembly, comprising:
[0005] The anode plate includes a first anode current collector and a second anode current collector connected to each other;
[0006] The cathode sheet includes a first cathode current collector and a second cathode current collector connected to each other;
[0007] The cathode sheet has a first bending portion and is bendable relative to the anode sheet, such that the first cathode current collector and the second cathode current collector are located on opposite sides of the first anode current collector and are stacked with the first anode current collector; the anode sheet is bendable relative to the cathode sheet, such that the second anode current collector is stacked with the cathode sheet, and the second anode current collector is located on the side of the cathode sheet away from the first anode current collector.
[0008] In some embodiments, the first cathode current collector is coated with a first cathode active layer, the second cathode current collector is coated with a second cathode active layer, and at the first bend, the first cathode active layer and the second cathode active layer are spaced apart.
[0009] In some embodiments, the cathode sheet includes a third cathode current collector connected to the second cathode current collector, the third cathode current collector being coated with a third cathode active layer, and the third cathode current collector being located on the side of the second cathode current collector opposite to the first cathode current collector;
[0010] The cathode sheet has a second bending portion and can be bent relative to the anode sheet, so that the second cathode current collector and the third cathode current collector are located on opposite sides of the second anode current collector and are stacked with the second anode current collector. At the second bending portion, the second cathode active layer and the third cathode active layer are spaced apart.
[0011] In some embodiments, the first bend is adapted to extend along a first direction, which is perpendicular to the length direction of the cathode sheet; and / or
[0012] The second bend is adapted to extend along a first direction, which is perpendicular to the length direction of the cathode sheet.
[0013] In some embodiments, at the first bend, the cathode sheet is provided with a first groove, and the first cathode active layer and the second cathode active layer are located on opposite sides of the first groove, so that the first cathode active layer and the second cathode active layer are spaced apart.
[0014] In some embodiments, at the first bend, the cathode sheet is provided with a first insulating layer, the first insulating layer connecting the first cathode active layer and the second cathode active layer, so that the first cathode active layer and the second cathode active layer are spaced apart.
[0015] In some embodiments, when the cathode sheet is bent relative to the anode sheet and the anode sheet is bent relative to the cathode sheet, the anode sheet has a first side edge with a first tab, the cathode sheet has a second side edge with a second tab, and the first side edge and the second side edge are located on the same side of the electrode assembly.
[0016] In some embodiments, when the cathode sheet is bent relative to the anode sheet and the anode sheet is bent relative to the cathode sheet, the anode sheet has a first side with a first tab, the cathode sheet has a second side with a second tab, and the first side and the second side are located on opposite sides of the electrode assembly.
[0017] In some embodiments, when the cathode sheet is not bent relative to the anode sheet, the spacing between the first cathode active layer and the second cathode active layer is K1, where K1 satisfies: 0.05mm≤K1≤5mm.
[0018] A second aspect of this utility model provides a battery, which includes the electrode assembly described in the above embodiments.
[0019] Compared with the prior art, the beneficial effects of this utility model include:
[0020] In the technical solution of this utility model, the electrode assembly includes an anode sheet and a cathode sheet. The anode sheet includes a first anode current collector and a second anode current collector connected to each other. The cathode sheet includes a first cathode current collector and a second cathode current collector connected to each other. In the prior art, the energy density of the battery is improved by increasing the silicon content. For wound cells, a higher silicon content leads to a larger negative electrode expansion volume, making the corner disadvantage of wound cells more obvious and reducing the space utilization rate of wound cells. Although stacked cells have a higher energy density and no corner problem, the manufacturing efficiency of stacked cells is lower, requiring the consumption of die-cutting molds, that is, the cost of stacked cells is higher, making it difficult to use on a large scale. The cathode sheet of this solution has a first bending portion and can be bent relative to the anode sheet, so that the first cathode current collector and the second cathode current collector are located on opposite sides of the first anode current collector and are stacked with the first anode current collector. The anode sheet can be bent relative to the cathode sheet so that the second anode current collector is stacked with the cathode sheet, and the second anode current collector is located on the side of the cathode sheet away from the first anode current collector. Since both the anode and cathode of the electrode assembly are single-piece electrodes, this solution eliminates the need for electrode cutting as required for laminated cells, thus avoiding the need for cutting dies, improving cell processing efficiency, and saving processing costs. In summary, this electrode assembly solution combines the advantages of both wound and laminated cells, balancing battery energy density and manufacturing efficiency. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0022] Figure 1 This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein the cathode sheet is bent relative to the anode sheet, and a first groove is shown;
[0023] Figure 2 This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein the anode plate and the cathode plate are spaced apart;
[0024] Figure 3 This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein, the first cathode current collector and the first anode current collector are stacked in layers;
[0025] Figure 4 This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein the anode plate is bent once relative to the cathode plate;
[0026] Figure 5This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein the cathode sheet is bent relative to the anode sheet through a first bending portion;
[0027] Figure 6 This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein the anode plate is bent twice relative to the cathode plate;
[0028] Figure 7 This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein the cathode sheet is bent relative to the anode sheet via a second bending portion;
[0029] Figure 8 This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein the anode plate is bent three times relative to the cathode plate;
[0030] Figure 9 This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein the first electrode tab and the second electrode tab are located on the same side of the anode and cathode electrodes;
[0031] Figure 10 This is a schematic diagram of an electrode assembly in one embodiment of the present invention; wherein the first electrode tab and the second electrode tab are located on opposite sides of the anode and cathode electrodes.
[0032] Explanation of icon numbers:
[0033] Electrode assembly 10;
[0034] Anode plate 100; First anode current collector 110; First anode active layer 111; Second anode current collector 120; First side 130; First tab 131;
[0035] Cathode sheet 200; First cathode current collector 210; First cathode active layer 211; Second cathode current collector 220; Second cathode active layer 221; First bending portion 230; Third cathode current collector 240; Second bending portion 250; First groove 260; First insulating layer 270; Second side 280; Second tab 281;
[0036] Diaphragm 300;
[0037] First direction X.
[0038] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0040] The first aspect of this utility model provides an electrode assembly 10 that avoids the corner disadvantages of the cathode sheet 200, ensuring the energy density and manufacturing efficiency of the battery cell. See below for reference. Figures 1 to 10 The electrode assembly 10 of this application embodiment will be introduced. Specifically, the electrode assembly 10 includes an anode plate 100 and a cathode plate 200.
[0041] Reference Figure 1 The anode plate 100 is the negative electrode of the battery. During battery discharge, the negative electrode material can undergo an oxidation reaction to release electrons. The anode plate 100 includes a first anode current collector 110 and a first anode active layer 111 coated on the first anode current collector 110. It can be understood that the first anode active layer 111 can be coated on one or both sides of the first anode current collector 110 along its thickness direction.
[0042] Reference Figure 1 The cathode sheet 200 is the positive electrode of the battery. During battery discharge, the positive electrode material can undergo a reduction reaction to obtain electrons. The cathode sheet 200 includes a first cathode current collector 210 and a second cathode current collector 220. The first cathode current collector 210 and the second cathode current collector 220 are connected to each other. The first cathode current collector 210 is coated with a first cathode active layer 211, and the second cathode current collector 220 is coated with a second cathode active layer 221. It can be understood that the first cathode active layer 211 can be coated on one or both sides of the first cathode current collector 210 along its thickness direction, and the second cathode active layer 221 can be coated on one or both sides of the second cathode current collector 220 along its thickness direction. In this embodiment, the first cathode active layer 211 and the second cathode active layer 221 are located on the same side of the cathode sheet 200 as an example.
[0043] Reference Figure 1 The cathode sheet 200 has a first bending portion 230 and is bendable relative to the anode sheet 100, such that the first cathode current collector 210 and the second cathode current collector 220 are located on opposite sides of the first anode current collector 110, and the first cathode current collector 210 and the second cathode current collector 220 are stacked with the first anode current collector 110. At the first bending portion 230 of the cathode sheet 200, the first cathode active layer 211 can be spaced apart from the second cathode active layer 221; in other words, the first bending portion 230 of the cathode sheet 200 is not coated with active material.
[0044] In the technical solution of this utility model, the electrode assembly 10 includes an anode sheet 100 and a cathode sheet 200. The anode sheet 100 includes a first anode current collector 110 and a first anode active layer 111 coated on the first anode current collector 110. The cathode sheet 200 includes a first cathode current collector 210 and a second cathode current collector 220 connected to each other. The first cathode current collector 210 is coated with the first cathode active layer 211, and the second cathode current collector 220 is coated with a second cathode active layer 221. In the prior art, the energy density of the battery is improved by increasing the silicon content. For wound cells, a higher silicon content leads to a larger negative electrode expansion volume, making the corner disadvantage of wound cells more obvious and reducing the space utilization rate of wound cells. Although stacked cells have a higher energy density and no corner problem, the manufacturing efficiency of stacked cells is lower, requiring the consumption of die-cutting molds, that is, the cost of stacked cells is higher, making it difficult to use on a large scale. The cathode sheet 200 of this design has a first bending portion 230 and can be bent relative to the anode sheet 100, such that the first cathode current collector 210 and the second cathode current collector 220 are located on opposite sides of the first anode current collector 110 and are stacked with the first anode current collector 110. At the first bending portion 230, the first cathode active layer 211 and the second cathode active layer 221 are arranged alternately, that is, no active material is coated at the first bending portion 230. Therefore, the cell of this design does not have the disadvantage of corners and can effectively avoid the situation of large negative electrode expansion volume, thus improving the space utilization of the cell. Furthermore, since both the anode and cathode of the electrode assembly 10 are single electrodes, this design does not require cutting the electrodes as in stacked cells, thus eliminating the need for cutting dies, improving cell processing efficiency and saving processing costs. In summary, the electrode assembly 10 of this design combines the advantages of wound cells and stacked cells, balancing battery energy density and manufacturing efficiency.
[0045] Reference Figure 2 and Figure 4In some embodiments, the anode sheet 100 includes a second anode current collector 120 and a second anode active layer coated on the second anode current collector 120, the second anode current collector 120 being connected to the first anode current collector 110. It is understood that the second anode active layer and the first anode active layer 111 can be coated on the same side of the anode sheet 100. The anode sheet 100 can be bent relative to the cathode sheet 200, such that the second anode current collector 120 is stacked with the cathode sheet 200. The second anode current collector 120 is located on the side of the cathode sheet 200 opposite to the first anode current collector 110. It should be noted that in some embodiments, the second anode active layer can be connected to the first anode active layer 111. In other embodiments, the second anode active layer can be spaced apart from the first anode active layer 111; this embodiment uses the connection of the second anode active layer and the first anode active layer 111 as an example for illustration. In this design, the second anode current collector 120 is stacked with the cathode plate 200, which enables the second anode current collector 120 to be connected with the first anode current collector 110, thereby increasing the energy density of the battery cell.
[0046] Reference Figures 2 to 4 In some embodiments, the cathode sheet 200 includes a third cathode current collector 240 connected to a second cathode current collector 220. The third cathode current collector 240 is coated with a third cathode active layer and is located on the side of the second cathode current collector 220 opposite to the first cathode current collector 210. It is understood that the third cathode active layer can be coated on one or both sides of the third cathode current collector 240. The cathode sheet 200 has a second bend 250 and is bendable relative to the anode sheet 100, such that the second cathode current collector 220 and the third cathode current collector 240 are located on opposite sides of the second anode current collector 120, and the second cathode current collector 220 and the third cathode current collector 240 are stacked with the second anode current collector 120. At the second bend 250 of the cathode sheet 200, the second cathode active layer 221 can be spaced apart from the third cathode active layer. In other words, the second bend 250 of the cathode sheet 200 is not coated with an active material. This solution can improve the energy density of the battery cell, prevent the corner disadvantage of the second bend 250, avoid the situation of large expansion volume of the negative electrode, and eliminate the need to cut the electrode sheets as is common in stacked battery cells, thus eliminating the need for cutting dies, improving battery cell processing efficiency and saving processing costs.
[0047] Reference Figures 2 to 6 The specific configuration of the first bending portion 230 is described below. In some embodiments, for ease of description and understanding of the structure of the first bending portion 230, a first direction X is defined, which is arranged perpendicular to the length direction of the cathode sheet 200. (Refer to...) Figure 2 The orientation, the first direction X can point to the left or right, that is, the first bending part 230 can be arranged to extend in the left or right direction.
[0048] Reference Figures 2 to 6 The specific configuration of the second bending portion 250 is described below. In some embodiments, for ease of description and understanding of the structure of the second bending portion 250, a first direction X is defined, which is perpendicular to the length direction of the cathode sheet 200. It can be understood that the extension direction of the second bending portion 250 can be the same as the extension direction of the first bending portion 230. (Refer to...) Figure 2 The orientation, the first direction X can point to the left or right, that is, the second bend 250 can be arranged to extend in the left or right direction.
[0049] Reference Figure 1 The specific spacing between the first cathode active layer 211 and the second cathode active layer 221 is described below. In some embodiments, at the first bend 230, the cathode sheet 200 is provided with a first groove 260, and the first cathode active layer 211 and the second cathode active layer 221 are located on opposite sides of the first groove 260, so that the first cathode active layer 211 and the second cathode active layer 221 are spaced apart. In other words, no active material layer is coated at the first bend 230, that is, the first cathode active layer 211 and the second cathode active layer 221 are not connected. This solution can avoid the disadvantage of the cell corner and improve the space utilization of the cell.
[0050] Reference Figure 2 and Figure 3 The specific spacing between the first cathode active layer 211 and the second cathode active layer 221 is described below. In some embodiments, at the first bend 230, the cathode sheet 200 is provided with a first insulating layer 270, which connects the first cathode active layer 211 and the second cathode active layer 221, thus spacing the first cathode active layer 211 and the second cathode active layer 221 apart. This solution can also avoid the cell corner problem and improve the space utilization of the cell.
[0051] Reference Figure 2 In some embodiments, when the cathode sheet 200 is not bent relative to the anode sheet 100, the spacing between the first cathode active layer 211 and the second cathode active layer 221 is K1, that is, the width of the first insulating layer 270 or the first groove 260 is K1. K1 satisfies: 0.05mm ≤ K1 ≤ 5mm. For example, K1 can be 0.05mm, 0.1mm, 1.4mm, 2mm, 2.5mm, 3.6mm, 4mm, or 5mm, etc. This solution can combine the advantages of wound cells and stacked cells, and ensure the energy density of the battery.
[0052] Reference Figure 9 and Figure 10The electrode tab configuration of the electrode assembly 10 is described below. In some embodiments, when the cathode sheet 200 is bent relative to the anode sheet 100 and the anode sheet 100 is bent relative to the cathode sheet 200, that is, after the electrode assembly 10 has completed its bending formation, the anode sheet 100 has a first side 130, and the first side 130 is provided with a first electrode tab 131, which is a negative electrode tab. The cathode sheet 200 has a second side 280, and the second side 280 is provided with a second electrode tab 281, which is a positive electrode tab. The first side 130 and the second side 280 are located on the same side of the electrode assembly 10, that is, the positive electrode tab and the negative electrode tab can be located on the same side of the electrode assembly 10. In other embodiments, when the cathode sheet 200 is bent relative to the anode sheet 100 and the anode sheet 100 is bent relative to the cathode sheet 200, that is, after the electrode assembly 10 has completed its bending formation, the electrode tab configuration is described below. The anode plate 100 has a first side 130, and the first side 130 is provided with a first tab 131. The cathode plate 200 has a second side 280, and the second side 280 is provided with a second tab 281. The first side 130 and the second side 280 are located on opposite sides of the electrode assembly 10, that is, the positive tab and the negative tab can be located on different sides of the electrode assembly 10, so that the anode and cathode can be provided with tabs with a bend in between. This solution can increase the number of tabs and significantly improve the dynamic performance of the battery.
[0053] A second aspect of this utility model provides a battery including the electrode assembly 10 described in the above embodiment. This battery solution, while ensuring its energy density, avoids the disadvantages of cell corners, prevents excessive expansion of the negative electrode, and improves the space utilization of the cell. Furthermore, this solution eliminates the need for electrode cutting as in stacked cells, thus avoiding the need for die-cutting, improving cell processing efficiency, and saving processing costs. It is understood that a separator 300 can be provided between the cathode plate 200 and the anode plate 100 of the battery.
[0054] Reference Figure 1 In some embodiments, the separator 300 can be thermally bonded to the negative electrode first, and then bonded to the positive electrode according to... Figures 2 to 10 At least some of the continuous steps in the process involve folding. In other embodiments, a separator 300 may also be coated onto the negative electrode using electrospinning technology. The specific configuration of the separator 300 may vary depending on the specific circumstances.
[0055] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0056] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or," "and / or," or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where A and B are simultaneously satisfied. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0057] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.
Claims
1. An electrode assembly, characterized in that, include: The anode plate includes a first anode current collector and a second anode current collector connected to each other; The cathode sheet includes a first cathode current collector and a second cathode current collector connected to each other; The cathode sheet has a first bending portion and is bendable relative to the anode sheet, such that the first cathode current collector and the second cathode current collector are located on opposite sides of the first anode current collector and are stacked with the first anode current collector; the anode sheet is bendable relative to the cathode sheet, such that the second anode current collector is stacked with the cathode sheet, and the second anode current collector is located on the side of the cathode sheet away from the first anode current collector.
2. The electrode assembly as described in claim 1, characterized in that, The first cathode current collector is coated with a first cathode active layer, and the second cathode current collector is coated with a second cathode active layer. At the first bend, the first cathode active layer and the second cathode active layer are spaced apart.
3. The electrode assembly as described in claim 2, characterized in that, The cathode sheet includes a third cathode current collector connected to the second cathode current collector. The third cathode current collector is coated with a third cathode active layer and is located on the side of the second cathode current collector opposite to the first cathode current collector. The cathode sheet has a second bending portion and can be bent relative to the anode sheet, so that the second cathode current collector and the third cathode current collector are located on opposite sides of the second anode current collector and are stacked with the second anode current collector. At the second bending portion, the second cathode active layer and the third cathode active layer are spaced apart.
4. The electrode assembly as described in claim 3, characterized in that, The first bend is adapted to extend along a first direction, which is perpendicular to the length direction of the cathode sheet; and / or, The second bend is adapted to extend along a first direction, which is perpendicular to the length direction of the cathode sheet.
5. The electrode assembly as described in claim 2, characterized in that, At the first bend, the cathode sheet is provided with a first groove, and the first cathode active layer and the second cathode active layer are located on opposite sides of the first groove, so that the first cathode active layer and the second cathode active layer are spaced apart.
6. The electrode assembly as described in claim 2, characterized in that, At the first bend, the cathode sheet is provided with a first insulating layer, which connects the first cathode active layer and the second cathode active layer, thereby spacing the first cathode active layer and the second cathode active layer apart.
7. The electrode assembly as described in claim 1, characterized in that, When the cathode plate is bent relative to the anode plate and the anode plate is bent relative to the cathode plate, the anode plate has a first side edge with a first tab on the first side edge, and the cathode plate has a second side edge with a second tab on the second side edge. The first side edge and the second side edge are located on the same side of the electrode assembly.
8. The electrode assembly as described in claim 1, characterized in that, When the cathode plate is bent relative to the anode plate and the anode plate is bent relative to the cathode plate, the anode plate has a first side edge with a first tab on the first side edge, and the cathode plate has a second side edge with a second tab on the second side edge. The first side edge and the second side edge are located on opposite sides of the electrode assembly.
9. The electrode assembly as described in claim 2, characterized in that, When the cathode sheet is not bent relative to the anode sheet, the spacing between the first cathode active layer and the second cathode active layer is K1, where K1 satisfies: 0.05mm≤K1≤5mm.
10. A battery, characterized in that, Includes the electrode assembly as described in any one of claims 1-8.