Electrode assembly, apparatus for manufacturing electrode assembly, and battery

Abstract

The utility model discloses an electrode assembly, a manufacturing device of the electrode assembly and a battery. An electrode assembly belongs to the technical field of batteries and comprises a positive plate, a negative plate and a diaphragm, the positive plate comprises a positive current collector and a positive material layer which are stacked, the surface, away from the positive current collector, of the positive material layer is a first matching surface, and a plurality of first protrusions and a plurality of first grooves are formed in the first matching surface; the negative plate comprises a negative current collector and a negative material layer which are stacked, the surface, deviating from the negative current collector, of the negative material layer is a second matching surface, and a plurality of second bulges and a plurality of second grooves are formed on the second matching surface, so that the corresponding effective reaction area of the first matching surface and the second matching surface can be increased, and the electrochemical reaction rate is increased; and the charging and discharging rate of the battery is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and more specifically, to an electrode assembly, a manufacturing apparatus, and a battery. Background Technology

[0002] Secondary batteries are widely used in mobile electronic devices, electric vehicles, solar energy storage and other fields. Secondary batteries mainly rely on the migration of ions between the positive and negative electrodes to achieve charging and discharging functions.

[0003] Currently, users have increasingly higher requirements for battery fast charging speeds, and how to improve battery charging speed is a pressing challenge that needs to be addressed. Utility Model Content

[0004] The present invention aims to at least partially solve one of the aforementioned technical problems in the prior art. Therefore, the first objective of the present invention is to provide an electrode assembly that facilitates improving the charge and discharge rate of a battery.

[0005] The second objective of this invention is to provide an apparatus for manufacturing an electrode assembly.

[0006] The third objective of this invention is to provide a battery.

[0007] The electrode assembly of this utility model embodiment includes: a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet includes: a positive current collector and a positive electrode material layer stacked together. The surface of the positive electrode material layer facing away from the positive current collector is a first mating surface. The first mating surface has a plurality of first protrusions and a plurality of first grooves. Any two adjacent first protrusions are connected by a first groove. The negative electrode sheet includes: a negative current collector and a negative electrode material layer stacked together. The surface of the negative electrode material layer facing away from the negative current collector is a second mating surface. The second mating surface has a plurality of second protrusions and a plurality of second grooves. Any two adjacent second protrusions are connected by a second groove. The separator is sandwiched between the first mating surface and the second mating surface. The plurality of first protrusions and the plurality of second grooves correspond one-to-one, with the first protrusions embedded in the corresponding second grooves, and the plurality of second protrusions and the plurality of first grooves correspond one-to-one, with the second protrusions embedded in the corresponding first grooves.

[0008] According to the electrode assembly of this utility model embodiment, the first mating surface of the positive electrode sheet is formed with a plurality of first protrusions and a plurality of first grooves, and the second mating surface of the negative electrode sheet is formed with a plurality of second protrusions and a plurality of second grooves. This is beneficial to increase the area of ​​the first mating surface and the area of ​​the second mating surface, thereby increasing the effective reaction area corresponding to the first mating surface and the second mating surface, so as to improve the electrochemical reaction rate and thus improve the charge and discharge rate of the battery.

[0009] According to some embodiments of this utility model, the intersection line of each first protrusion and the first groove connected thereto is located on a first average plane, and the distance between the first average plane and the positive current collector in the thickness direction of the positive electrode sheet is H. 11 The maximum distance between the first protrusion and the positive electrode current collector is H. 12 The minimum distance between the first groove and the positive electrode current collector is H. 13 The following relationship is satisfied: 128%H 11 ≤H 12 ≤142%H 11 58% H 11 ≤H 13 ≤72%H 11 The intersection line of each of the second protrusions and the second groove connected thereto lies on the second average plane. In the thickness direction of the negative electrode sheet, the distance between the second average plane and the negative electrode current collector is H. 21 The maximum distance between the second protrusion and the negative electrode current collector is H. 22 The minimum distance between the second groove and the negative electrode current collector is H. 23 The following relationship is satisfied: 128%H 21 ≤H 22 ≤142%H 21 58% H 21 ≤H 23 ≤72%H 21 .

[0010] According to some embodiments of the present invention, the H 11 Satisfies the relationship: 0.10mm≤H 11 ≤0.36mm.

[0011] According to some embodiments of this utility model, in the width direction of the positive electrode sheet, the first protrusion and the first groove are arranged alternately, and the width of the first protrusion is W. 11 The width of the first groove is W 12 The relationship is satisfied: 0.5mm≤W 11 ≤2.0mm, 0.5mm≤W 12 ≤2.0mm; in the width direction of the negative electrode sheet, the second protrusion and the second groove are arranged alternately, and the width of the second protrusion is W. 21 The width of the second groove is W 22 The relationship is satisfied: 0.5mm≤W 21 ≤2.0mm, 0.5mm≤W 22 ≤2.0mm.

[0012] According to some embodiments of the present invention, the first mating surface and the second mating surface are interlocking arc-shaped wavy surfaces.

[0013] According to some embodiments of the present invention, in the thickness direction of the positive electrode sheet, the positive electrode current collector is provided on both sides of the positive electrode material layer; in the thickness direction of the negative electrode sheet, the negative electrode current collector is provided on both sides of the negative electrode material layer.

[0014] According to some embodiments of the present invention, the first protrusion, the first groove, the second protrusion, and the second groove are all the same in shape and size.

[0015] According to some embodiments of the present invention, the diaphragm is provided with adhesive on both the side facing the first mating surface and the other side facing the second mating surface.

[0016] According to another embodiment of the present invention, an electrode assembly manufacturing apparatus is used to manufacture an electrode assembly as described above. The electrode assembly manufacturing apparatus includes: a conveying mechanism, an oven, and a mold. The conveying mechanism is used to drive the positive current collector or the negative current collector to move along a first direction. The oven is used to dry the positive electrode material layer or the negative electrode material layer. In the first direction, the mold is disposed at the upstream end of the oven. The mold has a shaping surface facing the positive electrode current collector or the negative electrode current collector. The shaping surface has a plurality of mold protrusions and a plurality of mold grooves extending along the first direction.

[0017] According to the electrode assembly manufacturing apparatus of the present invention, the first mating surface of the positive electrode sheet is formed with a plurality of first protrusions and a plurality of first grooves, and the second mating surface of the negative electrode sheet is formed with a plurality of second protrusions and a plurality of second grooves. This is beneficial to increasing the area of ​​the first mating surface and the area of ​​the second mating surface, thereby increasing the effective reaction area corresponding to the first mating surface and the second mating surface, so as to improve the reaction rate and thus improve the charging and discharging rate of the battery.

[0018] The battery according to another embodiment of the present invention includes the electrode assembly described above.

[0019] According to the battery of the present invention, the first mating surface of the positive electrode sheet is formed with a plurality of first protrusions and a plurality of first grooves, and the second mating surface of the negative electrode sheet is formed with a plurality of second protrusions and a plurality of second grooves. This is beneficial to increasing the area of ​​the first mating surface and the area of ​​the second mating surface, thereby increasing the effective reaction area corresponding to the first mating surface and the second mating surface, so as to improve the reaction rate and thus improve the charging and discharging rate of the battery.

[0020] Additional aspects and advantages of this invention 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 the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of an electrode assembly according to an embodiment of the present utility model;

[0022] Figure 2 This is a schematic diagram of the positive electrode sheet according to an embodiment of the present utility model;

[0023] Figure 3 This is a schematic diagram of the negative electrode sheet according to an embodiment of the present utility model;

[0024] Figure 4 This is a schematic diagram of an electrode assembly according to some other embodiments of the present invention;

[0025] Figure 5 This is a schematic diagram of an electrode assembly according to some other embodiments of the present invention;

[0026] Figure 6 This is a schematic diagram of an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of a mold according to an embodiment of the present utility model.

[0028] Figure label:

[0029] Positive electrode 1; Positive current collector 11; Positive electrode material layer 12; First protrusion 121; First groove 122; First mating surface 123;

[0030] Negative electrode sheet 2; negative electrode current collector 21; negative electrode material layer 22; second protrusion 221; second groove 222; second mating surface 223;

[0031] 3. Diaphragm; 10. Electrode assembly;

[0032] Manufacturing device 20; conveying mechanism 201; oven 202; mold 203; shaping surface 2031; mold protrusion 2032; mold groove 2033; suspension bracket 204. Detailed Implementation

[0033] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0034] In the description of this utility model, it should be understood that the terms "length", "width", "thickness", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this utility model and simplifying the description, and 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 this utility model.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., 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, an electrical connection, or a connection that allows communication between them; 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 according to the specific circumstances.

[0037] The following is combined with Figures 1-7 The present invention describes in detail the electrode assembly 10, the manufacturing apparatus 20 for the electrode assembly 10, and the battery according to embodiments of the present invention.

[0038] Reference Figures 1-5As shown, the electrode assembly 10 of this utility model embodiment includes: a positive electrode 1, a negative electrode 2, and a separator 3. The positive electrode 1 includes a positive current collector 11 and a positive electrode material layer 12 stacked together. The surface of the positive electrode material layer 12 facing away from the positive current collector 11 is a first mating surface 123. The first mating surface 123 has a plurality of first protrusions 121 and a plurality of first grooves 122. Any two adjacent first protrusions 121 are connected by a first groove 122. The negative electrode 2 includes a negative current collector 21 and a negative electrode material layer 22 stacked together. The negative electrode material layer 22 faces away from the negative current collector. The surface of 21 is a second mating surface 223. The second mating surface 223 has a plurality of second protrusions 221 and a plurality of second grooves 222. Any two adjacent second protrusions 221 are connected by a second groove 222. The diaphragm 3 is sandwiched between the first mating surface 123 and the second mating surface 223. The plurality of first protrusions 121 and the plurality of second grooves 222 correspond one-to-one. The first protrusions 121 are embedded in the corresponding second grooves 222. The plurality of second protrusions 221 and the plurality of first grooves 122 correspond one-to-one. The second protrusions 221 are embedded in the corresponding first grooves 122.

[0039] It is understood that the electrode assembly 10 can be used in a battery, which can be a lithium-ion battery. Both the positive electrode material layer 12 and the negative electrode material layer 22 can contain active materials, conductive agents, and binders. The active material of the positive electrode material layer 12 can be selected from ternary materials, lithium iron phosphate, etc., and the active material of the negative electrode material layer 22 can be selected from graphite, lithium titanate, etc. The separator 3 is sandwiched between the first mating surface 123 and the second mating surface 223. The separator 3 is suitable for blocking electrons and allowing lithium ions to pass through. When the lithium battery is charging, electrons can flow from the positive electrode current collector 11 to the negative electrode current collector 21 through the external circuit, and lithium ions are extracted from the positive electrode material layer 12. The lithium ions can migrate to the negative electrode material layer 22 through the separator 3 and embed themselves in the negative electrode material layer 22. When the lithium battery is discharging, lithium ions are extracted from the negative electrode material layer 22 and release electrons. The electrons can flow from the negative electrode current collector 21 to the electrical device through the external circuit to supply power to the electrical device.

[0040] The first mating surface 123 has multiple first protrusions 121 and multiple first grooves 122, which helps to increase the area of ​​the first mating surface 123. The second mating surface 223 has multiple second protrusions 221 and multiple second grooves 222, which helps to increase the area of ​​the second mating surface 223. This can increase the effective reaction area corresponding to the first mating surface 123 and the second mating surface 223, thereby improving the electrochemical reaction rate and thus helping to improve the charge and discharge rate of the battery.

[0041] Multiple first protrusions 121 and multiple second grooves 222 correspond one-to-one. The first protrusions 121 are embedded in the corresponding second grooves 222, and the multiple second protrusions 221 and multiple first grooves 122 correspond one-to-one. The second protrusions 221 are embedded in the corresponding first grooves 122. This facilitates the migration of lithium ions along a direction that is convenient for transport. In other words, by setting up the first mating surface 123 and the second mating surface 223 with alternating concave and convex surfaces, the migration direction of lithium ions is no longer limited to the direction perpendicular to the positive electrode current collector 11 and the negative electrode current collector 21. Lithium ions can migrate in multiple directions. Lithium ions can migrate along the normal direction of the undulating separator 3, which can effectively shorten the migration path of lithium ions and improve the migration efficiency of lithium ions. This is conducive to improving the charging and discharging rate of the battery, reducing the internal resistance of the battery, reducing the heat generation of the battery, and extending the service life of the battery.

[0042] According to the electrode assembly 10 of this utility model embodiment, the first mating surface 123 of the positive electrode 1 is formed with a plurality of first protrusions 121 and a plurality of first grooves 122, and the second mating surface 223 of the negative electrode 2 is formed with a plurality of second protrusions 221 and a plurality of second grooves 222. This is beneficial to increase the area of ​​the first mating surface 123 and the area of ​​the second mating surface 223, thereby increasing the effective reaction area corresponding to the first mating surface 123 and the second mating surface 223, so as to improve the electrochemical reaction rate and thus improve the charge and discharge rate of the battery.

[0043] In some embodiments of this utility model, reference is made to Figure 2 and Figure 3 As shown, the intersection line of each first protrusion 121 and the first groove 122 connected to it is located on the first average plane. In the thickness direction of the positive electrode sheet 1, the distance between the first average plane and the positive electrode current collector 11 is H. 11 The maximum distance between the first protrusion 121 and the positive current collector 11 is H. 12 The minimum distance between the first groove 122 and the positive current collector 11 is H. 13 The following relationship is satisfied: 128%H 11 ≤H 12 ≤142%H 11 58% H 11 ≤H 13 ≤72%H 11 The intersection line of each second protrusion 221 and the second groove 222 connected thereto is located on the second average plane. In the thickness direction of the negative electrode sheet 2, the distance between the second average plane and the negative electrode current collector 21 is H. 21 The maximum distance between the second protrusion 221 and the negative electrode current collector 21 is H. 22 The minimum distance between the second groove 222 and the negative electrode current collector 21 is H. 23 The following relationship is satisfied: 128%H 21 ≤H22 ≤142%H 21 58% H 21 ≤H 23 ≤72%H 21 For example, in some embodiments, H 13 58% H 11 H 12 142% H 11 H 22 142% H 21 H 23 58% H 21 In other embodiments, H 13 72% H 11 H 12 128% H 11 H 22 128% H 21 H 23 72% H 21 In some other embodiments, H 13 65% H 11 H 12 135% H 11 H 22 135% H 21 H 23 It is 65% H2.

[0044] Understandably, H 11 It can be the average thickness of the positive electrode material layer 12, when H 13 <58% H 11 When the minimum distance between the first groove 122 and the positive electrode current collector 11 is small, the thickness of the positive electrode material layer 12 at the first groove 122 is small, resulting in a poorer lithium intercalation capability of the positive electrode material layer 12 at the first groove 122. 13 >72% H 11 At that time, the depth of the first groove 122 was relatively small, which limited the migration efficiency of lithium ions. 13 At 58% H 11 ~72% H 11 Within the specified range, the lithium intercalation capability of the positive electrode material layer 12 can be guaranteed, and the charging rate of the battery can be effectively improved.

[0045] Similarly, H 21 It can be the average thickness of the negative electrode material layer 22, when H 23 <58% H 21 When the minimum distance between the second groove 222 and the negative electrode current collector 21 is small, the thickness of the negative electrode material layer 22 at the second groove 222 is small, resulting in a decrease in the lithium intercalation capability of the negative electrode material layer 22 at the second groove 222. 23 >72% H21 At that time, the depth of the second groove 222 is relatively small, which limits the migration efficiency of lithium ions. 23 At 58% H 21 ~72% H 21 Within the specified range, the lithium intercalation capability of the negative electrode material layer 22 can be guaranteed, and the charging rate of the battery can be effectively improved.

[0046] In some embodiments of this utility model, H 11 Satisfies the relationship: 0.10mm≤H 11 ≤0.36mm, for example, H 11 The thickness can be 0.10mm, 0.22mm, or 0.36mm, which can ensure that the electrode assembly 10 has a high energy density. At the same time, when using a thicker positive electrode material layer 12, the first mating surface 123 and the second mating surface 223 with their concave and convex shapes can be used to make lithium ions migrate in a direction that facilitates transport, shortening the migration path of lithium ions from the positive electrode material layer 12 to the negative electrode material layer 22 and improving the charging rate of the battery.

[0047] It is understandable that if H 11 <0.10mm, the distance between the first average surface and the positive current collector 11 is small, the thickness of the positive electrode material layer 12 is small, and the amount of active material in the positive electrode material layer 12 is small, thereby reducing the energy density of the electrode assembly 10. If H 11 The thickness is >0.36mm, the distance between the first average surface and the positive electrode current collector 11 is relatively large, the thickness of the positive electrode material layer 12 is relatively large, and the migration path of lithium ions from the positive electrode material layer 12 to the negative electrode material layer 22 is relatively long, resulting in a lower battery charging rate. In this embodiment, H 11 Within the range of 0.10 mm to 0.36 mm, the energy density of the electrode assembly 10 can be guaranteed while shortening the migration path of lithium ions from the positive electrode material layer 12 to the negative electrode material layer 22, which is beneficial to improving the charging rate of the battery.

[0048] In some embodiments of this utility model, H 21 and H 11 The following relation can be satisfied: H 21 ≥H 11 H 21 The ratio of negative electrode capacity to positive electrode capacity can be adjusted appropriately based on the NP ratio (Negative / Positive Ratio) between negative electrode 2 and positive electrode 1.

[0049] In some embodiments of this utility model, reference is made to Figure 2 As shown, in the width direction of the positive electrode 1, the first protrusion 121 and the first groove 122 are arranged alternately, and the width of the first protrusion 121 is W. 11The width of the first groove 122 is W. 12 The relationship is satisfied: 0.5mm≤W 11 ≤2.0mm, 0.5mm≤W 12 ≤2.0mm, for example, W 11 It can be 0.5mm, 1mm, 1.5mm, 2mm, W 12 The widths can be 0.5mm, 1mm, 1.5mm, or 2mm. The widths of the first protrusion 121 and the first groove 122 are moderate to facilitate the processing and manufacturing of the positive electrode 1 and to increase the effective reaction area corresponding to the first mating surface 123 and the second mating surface 223.

[0050] Understandably, if W 11 <0.5mm, W 12 <0.5mm, the width of the first protrusion 121 and the first groove 122 is small, and the number of the first protrusion 121 and the first groove 122 is large, which increases the difficulty of manufacturing the positive electrode 1. If W 11 >0.5mm, W 12 >0.5mm, the number of first protrusions 121 and first grooves 122 is relatively small, and the effect of increasing the effective reaction area corresponding to the first mating surface 123 and the second mating surface 223 is not obvious. W 11 Within the range of 0.5mm to 2.0mm, W 12 Within the range of 0.5mm to 2.0mm, the width of the first protrusion 121 and the first groove 122 are moderate, and the number of the first protrusion 121 and the first groove 122 is moderate, which can reduce the manufacturing difficulty of the positive electrode 1 while increasing the effective reaction area corresponding to the first mating surface 123 and the second mating surface 223.

[0051] Reference Figure 3 As shown, in the width direction of the negative electrode 2, the second protrusion 221 and the second groove 222 are arranged alternately, and the width of the second protrusion 221 is W. 21 The width of the second groove 222 is W 22 The relationship is satisfied: 0.5mm≤W 21 ≤2.0mm, 0.5mm≤W 22 ≤2.0mm, for example, W 21 It can be 0.5mm, 1mm, 1.5mm, 2mm, W 22 The widths can be 0.5mm, 1mm, 1.5mm, or 2mm. The widths of the second protrusion 221 and the second groove 222 are moderate to facilitate the processing and manufacturing of the negative electrode sheet 2 and to increase the effective reaction area corresponding to the first mating surface 123 and the second mating surface 223.

[0052] Understandably, if W 21 <0.5mm, W22 <0.5mm, the width of the second protrusion 221 and the second groove 222 are small, and the number of second protrusions 221 and second grooves 222 is large, which increases the difficulty of manufacturing the negative electrode 2. If W 21 >0.5mm, W 22 >0.5mm, the number of second protrusions 221 and second grooves 222 is relatively small, and the effect of increasing the connection area between the first mating surface 123 and the second mating surface 223 is not obvious. W 21 Within the range of 0.5mm to 2.0mm, W 22 Within the range of 0.5mm to 2.0mm, the width of the second protrusion 221 and the second groove 222 are moderate, and the number of the second protrusion 221 and the second groove 222 is moderate. This can reduce the manufacturing difficulty of the negative electrode sheet 2 while increasing the connection area between the first mating surface 123 and the second mating surface 223.

[0053] In some embodiments of this utility model, reference is made to Figures 1-3 As shown, the first mating surface 123 and the second mating surface 223 are interlocking arc-shaped wavy surfaces. That is to say, the first mating surface 123 and the second mating surface 223 can interlock with each other through the diaphragm 3 to avoid interruption of the lithium ion transport path. At the same time, the surfaces of the first protrusion 121 and the second protrusion 221 are non-sharp arc-shaped surfaces, which can effectively reduce the risk of the first protrusion 121 and the second protrusion 221 puncturing the diaphragm 3.

[0054] In other embodiments of this utility model, reference is made to Figure 4 As shown, the first mating surface 123 and the second mating surface 223 are mutually meshing rectangular wave surfaces. This structure is simple and facilitates the processing and fabrication of the positive electrode 1 and the negative electrode 2. Both the first mating surface 123 and the second mating surface 223 are rounded at the corners to form smooth arc surfaces at the corners, which can effectively reduce the risk of puncturing the diaphragm 3.

[0055] In other embodiments of this utility model, reference is made to Figure 5 As shown, the first mating surface 123 and the second mating surface 223 are interlocking triangular wave surfaces. This structure is simple and facilitates the processing and manufacturing of the positive electrode 1 and the negative electrode 2. Both the first mating surface 123 and the second mating surface 223 are rounded at the corners to form smooth arc surfaces at the corners, which can effectively reduce the risk of puncturing the diaphragm 3.

[0056] In some embodiments of this utility model, positive electrode material layers 12 are provided on both sides of the positive electrode current collector 11 in the thickness direction of the positive electrode sheet 1, and negative electrode material layers 22 are provided on both sides of the negative electrode current collector 21 in the thickness direction of the negative electrode sheet 2, which can effectively improve the overall capacity of the electrode assembly 10. The positive electrode material layers 12 on both sides of the positive electrode current collector 11 are symmetrically arranged in a plane with respect to the center of the positive electrode current collector 11, and the negative electrode material layers 22 on both sides of the negative electrode current collector 21 are symmetrically arranged in a plane with respect to the center of the negative electrode current collector 21.

[0057] In some embodiments of this utility model, reference is made to Figure 1 As shown, the first protrusion 121, the first groove 122, the second protrusion 221, and the second groove 222 are all identical in shape and size. This ensures that the first protrusion 121 and the second groove 222 are tightly attached to the separator 3 on both sides without gaps, and the second protrusion 221 and the first groove 122 are also tightly attached to the separator 3 on both sides without gaps. This prevents interruption of the lithium-ion transport path, thereby improving the battery's charge and discharge rate. Furthermore, since the first protrusion 121, the first groove 122, the second protrusion 221, and the second groove 222 are all identical in shape and size, the same processing equipment can be used to process the positive electrode material layer 12 and the negative electrode material layer 22, reducing the number of processing devices and saving on equipment investment costs.

[0058] In some embodiments of this utility model, adhesive is provided on both the side of the diaphragm 3 facing the first mating surface 123 and the other side facing the second mating surface. When the electrode assembly 10 is assembled, the positive electrode 1 and the negative electrode 2 can be quickly bonded together by the adhesive on both sides of the diaphragm 3. The assembly process is simple and convenient, which helps to improve the assembly efficiency of the electrode assembly 10.

[0059] In related technologies, to address the distribution and diffusion characteristics of lithium ion and electron concentrations in electrochemical systems, common electrode design methods include multilayer slurry coating, electrode laser etching, and adding magnetic materials to induce particle alignment. The purpose of these methods is to adjust the electrode porosity to enable rapid transport of lithium ions to the depths of the electrode (closer to the current collector).

[0060] However, multi-layer coating requires the preparation of slurries with varying proportions of different substances, making the process complex. Furthermore, during coating, issues such as material shedding, electrode wrinkling, and the floating of fine particles from conductive agents and binders can cause cross-contamination of the slurry layers, altering the proportions of the substances in each layer. Electrode laser etching requires the introduction of new laser emission equipment, increasing the process and cost, and the ablation of the electrode material results in material loss and waste. Adding magnetic materials to induce particle alignment requires the introduction of magnetic materials, reducing the proportion of active material and lowering the energy density.

[0061] According to the electrode assembly 10 of this embodiment, compared with traditional thick electrodes, lithium ions can migrate along any direction that facilitates transport, shortening the migration path of lithium ions, improving the migration efficiency of lithium ions, which is beneficial for reducing internal resistance, reducing heat generation, and improving fast charging speed. Compared with multi-layer slurry coating, this embodiment does not require the preparation of slurries with multiple material ratios, but only requires the preparation of a slurry with a single ratio for single-layer coating. No measures are needed to address the mutual invasion of materials between layers in multi-layer coating, nor are any measures needed to address wrinkles caused by uneven expansion ratios of materials in multi-layer coating. Compared with electrode laser etching, this embodiment does not require the introduction of new equipment; only simple tooling needs to be added to a suitable position on the coating machine, and there is no material loss due to laser etching. Compared with electrodes with magnetically induced active material particle alignment, this embodiment does not require the introduction of magnetic materials, has a high proportion of active materials, and high energy density.

[0062] Reference Figure 6 and Figure 7 As shown, according to another embodiment of the present invention, an electrode assembly 10 manufacturing apparatus 20 is used to manufacture the electrode assembly 10 as described above. The electrode assembly 10 manufacturing apparatus 20 includes a conveying mechanism 201, an oven 202, and a mold 203. The conveying mechanism 201 is used to drive the positive electrode current collector 11 or the negative electrode current collector 21 to move along a first direction. The oven 202 is used to dry the positive electrode material layer 12 or the negative electrode material layer 22. In the first direction, the mold 203 is disposed in the upper part of the oven 202. At the upstream end, the mold 203 has a shaping surface 2031 facing the positive current collector 11 or the negative current collector 21. The shaping surface 2031 has a plurality of mold protrusions 2032 and a plurality of mold grooves 2033 extending along a first direction. The plurality of mold protrusions 2032 and the plurality of mold grooves 2033 of the shaping surface 2031 can be used to form a plurality of first grooves 122 and a plurality of first protrusions 121 of the first mating surface 123, or to form a plurality of second grooves 222 and a plurality of second protrusions 221 of the second mating surface 223.

[0063] Understandably, during the manufacturing of the positive electrode sheet 1, a slurry for forming the positive electrode material layer 12 can be first coated onto the positive electrode current collector 11. The conveying mechanism 201 drives the positive electrode current collector 11 and the slurry to move together along the first direction. The positive electrode current collector 11 and the slurry can first move to the upstream end of the oven 202. At this time, the slurry is wet. When the slurry touches the molding surface 2031 located at the upstream end of the oven 202, it forms a shape opposite to the molding surface 2031, which has multiple mold protrusions 2032 and multiple mold grooves 2033. The slurry forms a first groove 122 of the positive electrode material layer 12 at the corresponding mold protrusion 2032, and a first protrusion 121 of the positive electrode material layer 12 at the corresponding mold groove 2033. Under the baking at the upstream end of the oven 202, the slurry is not completely dried and maintains the shape of the first forming surface. Subsequently, the positive electrode current collector 11 and the slurry continue to move along the first direction to the downstream end of the oven 202 so that the slurry is completely dried into dry material, i.e., the positive electrode material layer 12, thereby completing the production of the positive electrode sheet 1. The production process of the negative electrode sheet 2 is similar to that of the positive electrode sheet 1, and will not be described in detail here.

[0064] The length of mold 203 is within the range of the slurry that is not completely dried. The width of mold 203 must include the width of the entire coated slurry. The height of mold 203 is not limited. The upper surface of mold 203 is fixedly connected to the top of oven 202 (the connection method is not limited; for example, refer to...). Figure 6 As shown, a hanging bracket 204 can be fixedly connected to the top of the oven 202. The lower surface of the mold 203 is in contact with the slurry. The mold protrusion 2032 and the mold groove 2033 of the mold 203 are parallel to the plane in the first direction (coating belt direction) and extend in the coating belt direction, maintaining the shape of the structure until the end position of the mold 203.

[0065] According to the manufacturing apparatus 20 of the electrode assembly 10 of the present invention, the positive electrode 1 of the electrode assembly 10 has a plurality of first protrusions 121 and a plurality of first grooves 122 formed on the first mating surface 123, and the negative electrode 2 has a plurality of second protrusions 221 and a plurality of second grooves 222 formed on the second mating surface 223. This is beneficial to increase the area of ​​the first mating surface 123 and the area of ​​the second mating surface 223, thereby increasing the effective reaction area corresponding to the first mating surface 123 and the second mating surface 223, so as to improve the electrochemical reaction rate and thus improve the charge and discharge rate of the battery.

[0066] In some embodiments of this utility model, the mold 203 is movably and / or detachably connected to the oven 202. The position of the mold 203 can be adjusted by moving and / or disassembling the mold 203 so that the shaping surface 2031 of the mold 203 corresponds to the first mating surface 123 of the positive electrode 1 or the second mating surface 223 of the negative electrode 2. This facilitates the use of the same mold 203 to process the first mating surface 123 of the positive electrode 1 and the second mating surface 223 of the negative electrode 2, thereby reducing the types and number of molds 203 and lowering the design and investment costs of the mold 203.

[0067] The battery according to another embodiment of the present invention includes the electrode assembly 10 described above.

[0068] According to the battery of the present invention, the first mating surface 123 of the positive electrode 1 is formed with a plurality of first protrusions 121 and a plurality of first grooves 122, and the second mating surface 223 of the negative electrode 2 is formed with a plurality of second protrusions 221 and a plurality of second grooves 222. This is beneficial to increasing the area of ​​the first mating surface 123 and the area of ​​the second mating surface 223, thereby increasing the effective reaction area corresponding to the first mating surface 123 and the second mating surface 223, so as to improve the electrochemical reaction rate and thus improve the charge and discharge rate of the battery.

[0069] In some embodiments of this utility model, the method for manufacturing the battery includes the following steps:

[0070] Step S1: Homogenize.

[0071] Among them, the positive electrode material layer 12 can be made of ternary materials, lithium iron phosphate and other active materials, and the negative electrode material layer 22 can be made of graphite, lithium titanate and other active materials. The homogenization process must ensure that the solid content, particle fineness and viscosity of the slurry meet the coating requirements.

[0072] Step S2: Coating.

[0073] The coating process can utilize the manufacturing apparatus 20 of the electrode assembly 10 according to this embodiment of the invention. This apparatus has a mold 203 located upstream of the oven 202. The electrode slurry forming process is as follows: looking along the coating belt direction, the flowing slurry encounters the lower surface of the mold 203 and forms a shape opposite to that of the lower surface of the mold 203. The slurry then continues to flow forward in the first direction, gradually being dried. When the slurry is about to be dried into a dry material, it exits the mold 203. The slurry retains its shape and continues to be dried in the oven 202, forming a shape opposite to the structure of the lower surface of the mold 203. The concave and convex shapes of the lower surfaces of the molds 203 used for the positive and negative electrodes of the same electrode assembly 10 need to be set oppositely.

[0074] Step S3: Die-cutting.

[0075] Depending on the shape of the battery cell, either metal die-cutting or laser die-cutting can be selected.

[0076] It should be noted that rolling is not required before die cutting to ensure the shape of the first mating surface 123 and the second mating surface 223.

[0077] Step S4: Assembly.

[0078] The separator 3 can be a separator with double-sided adhesive, and the assembly method can be a stacking method: specifically, the first groove 122 of the positive electrode material layer 12 corresponds to the second protrusion 221 of the negative electrode material layer 22, and the first protrusion 121 of the positive electrode material layer 12 corresponds to the second groove 222 of the negative electrode material layer 22. The shape, width and height of the first groove 122 and the second protrusion 221 must be consistent, and the shape, width and height of the first protrusion 121 and the second groove 222 must be consistent to ensure that the corresponding grooves and protrusions of the positive electrode material layer 12 and the negative electrode material layer 22 can be interlocked.

[0079] Regarding the overhang: The direction in which at least one side of the electrode (positive electrode 1 and negative electrode 2) has a tab is called the length direction, and the direction in which neither side of the electrode has a tab is called the width direction. In the length direction of the electrode, the length of the negative electrode 2 is greater than the length of the positive electrode. The distance between the width of one or two grooves or protrusions on each side of the length direction of the electrode (the width of the grooves and protrusions of the same electrode should be equal) is called the overhang. The dimensions of the separator 3 over the negative electrode 2 in the length direction of the electrode, the dimensions of the negative electrode 2 over the positive electrode 1 in the width direction of the electrode, and the dimensions of the separator 3 over the negative electrode 2 in the width direction of the electrode can be set according to the overhang requirements.

[0080] The positive electrode 1, negative electrode 2, and separator 3 are stacked to form an electrode assembly 10. The electrode assembly 10 needs to be hot-pressed to stabilize the relative positions of the positive electrode 1, negative electrode 2, and separator 3 within the electrode assembly 10.

[0081] Step S5: Shell insertion, liquid injection, formation, and aging.

[0082] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0083] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An electrode assembly, characterized in that, include: A positive electrode sheet (1) includes: a positive current collector (11) and a positive material layer (12) stacked together. The surface of the positive material layer (12) facing away from the positive current collector (11) is a first mating surface (123). The first mating surface (123) is formed with a plurality of first protrusions (121) and a plurality of first grooves (122). Any two adjacent first protrusions (121) are connected by a first groove (122). The negative electrode sheet (2) includes: a negative electrode current collector (21) and a negative electrode material layer (22) stacked together. The surface of the negative electrode material layer (22) facing away from the negative electrode current collector (21) is a second mating surface (223). The second mating surface (223) is formed with a plurality of second protrusions (221) and a plurality of second grooves (222). Any two adjacent second protrusions (221) are connected by a second groove (222). A diaphragm (3) is sandwiched between the first mating surface (123) and the second mating surface (223); Among them, multiple first protrusions (121) and multiple second grooves (222) correspond one-to-one, the first protrusions (121) are embedded in the corresponding second grooves (222), and multiple second protrusions (221) and multiple first grooves (122) correspond one-to-one, the second protrusions (221) are embedded in the corresponding first grooves (122).

2. The electrode assembly according to claim 1, characterized in that, The intersection line of each of the first protrusions (121) and the first groove (122) connected thereto lies on a first average plane. In the thickness direction of the positive electrode sheet (1), the distance between the first average plane and the positive electrode current collector (11) is H. 11 The maximum distance between the first protrusion (121) and the positive current collector (11) is H. 12 The minimum distance between the first groove (122) and the positive current collector (11) is H. 13 The following relationship is satisfied: 128%H 11 ≤H 12 ≤142%H 11 58% H 11 ≤H 13 ≤72%H 11 ; The intersection line of each of the second protrusions (221) and the second groove (222) connected thereto lies on the second average plane. In the thickness direction of the negative electrode sheet (2), the distance between the second average plane and the negative electrode current collector (21) is H. 21 The maximum distance between the second protrusion (221) and the negative electrode current collector (21) is H. 22 The minimum distance between the second groove (222) and the negative electrode current collector (21) is H. 23 The following relationship is satisfied: 128%H 21 ≤H 22 ≤142%H 21 58% H 21 ≤H 23 ≤72%H 21 .

3. The electrode assembly according to claim 2, characterized in that, The H 11 Satisfies the relationship: 0.10mm≤H 11 ≤0.36mm.

4. The electrode assembly according to claim 3, characterized in that, In the width direction of the positive electrode (1), the first protrusion (121) and the first groove (122) are arranged alternately, and the width of the first protrusion (121) is W. 11 The width of the first groove (122) is W 12 The relationship is satisfied: 0.5mm≤W 11 ≤2.0mm, 0.5mm≤W 12 ≤2.0mm; In the width direction of the negative electrode (2), the second protrusion (221) and the second groove (222) are arranged alternately, and the width of the second protrusion (221) is W. 21 The width of the second groove (222) is W 22 The relationship is satisfied: 0.5mm≤W 21 ≤2.0mm, 0.5mm≤W 22 ≤2.0mm.

5. The electrode assembly according to claim 1, characterized in that, The first mating surface (123) and the second mating surface (223) are interlocking arc-shaped wavy surfaces.

6. The electrode assembly according to claim 1, characterized in that, In the thickness direction of the positive electrode sheet (1), the positive electrode current collector (11) has a positive electrode material layer (12) on both sides; In the thickness direction of the negative electrode sheet (2), the negative electrode current collector (21) has a negative electrode material layer (22) on both sides.

7. The electrode assembly according to any one of claims 1-6, characterized in that, The first protrusion (121), the first groove (122), the second protrusion (221), and the second groove (222) are all the same in shape and size.

8. The electrode assembly according to claim 1, characterized in that, The diaphragm (3) is provided with adhesive on the side facing the first mating surface (123) and on the other side facing the second mating surface.

9. An apparatus for manufacturing an electrode assembly, characterized in that, The electrode assembly manufacturing apparatus is used to manufacture the electrode assembly as described in any one of claims 1-8, and the electrode assembly manufacturing apparatus comprises: A conveying mechanism (201) is used to drive the positive current collector (11) or the negative current collector (21) to move along a first direction; An oven (202) is used to dry the positive electrode material layer (12) or the negative electrode material layer (22); The mold (203) is located at the upstream end of the oven (202) in the first direction. The mold (203) has a shaping surface (2031) facing the positive current collector (11) or the negative current collector (21). The shaping surface (2031) has a plurality of mold protrusions (2032) and a plurality of mold grooves (2033) extending in the first direction.

10. A battery, characterized in that, Includes the electrode assembly according to any one of claims 1-8.

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