Composite pole piece, battery and electric equipment

Abstract

The utility model provides a composite pole piece, a battery and electric equipment, the composite pole piece comprises a first current collector, a first electrode material layer, a second electrode material layer and a second current collector, and the first current collector, the first electrode material layer, the second current collector and the second electrode material layer are sequentially stacked in a first direction, the second current collector is provided with at least one first through hole, the multiple first through holes penetrate through the second current collector in the first direction, and the orthographic projection of the first electrode material layer and / or the second electrode material layer on the second current collector covers the at least one first through hole. The battery performance is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a composite pole piece, a battery and an electrical device. Background Art

[0002] In order to effectively deal with the energy crisis and environmental pollution, people have focused on the effective use of sustainable energy. Lithium-ion batteries can store sustainable energy efficiently and cleanly, and have high charging and discharging performance. They are widely used in products such as electric vehicles.

[0003] In order to ensure the safety of lithium batteries during use and prevent lithium deposition in the negative electrode of lithium batteries during use, the method of reducing the surface density and compaction density of electrode materials is usually adopted to ensure the diffusion efficiency of lithium ions. However, the above method will greatly reduce the energy density of the battery, thereby reducing the capacity of the battery. Utility Model Content

[0004] The purpose of the present application is to provide a composite electrode, a battery and an electrical device to solve the problem of low lithium ion diffusion efficiency.

[0005] To achieve the purpose of this application, this application provides the following technical solutions:

[0006] The present application provides a composite electrode sheet, comprising: a first current collector; a first electrode material layer and a second electrode material layer, which are arranged on the same side of the first current collector; a second current collector, which is arranged between the first electrode material layer and the second electrode material layer, wherein the first current collector, the first electrode material layer, the second current collector and the second electrode material layer are stacked in sequence in a first direction, the second current collector has at least one first through hole, the at least one first through hole penetrates the second current collector along the first direction, and the orthographic projection of the first electrode material layer and / or the second electrode material layer on the second current collector covers at least one of the first through holes.

[0007] In a possible implementation manner, the number of the first through holes is at least two, the at least two first through holes are arranged in an array on the second current collector, and the minimum distance between two adjacent first through holes is 150 μm-900 μm.

[0008] In a possible implementation manner, it is characterized in that the shape of the first through hole is circular, and the diameter of the first through hole is 50 μm-400 μm.

[0009] In one possible embodiment, the second direction and the third direction are both perpendicular to the first direction, the second direction is perpendicular to the third direction, the at least one first through hole is spaced apart from the edge of the second current collector on at least one side in the second direction, and the minimum distance between the at least one first through hole and the edge of the second current collector in the second direction is greater than the minimum distance between the at least one first through hole and the edge of the second current collector in the third direction.

[0010] In a possible implementation, the second current collector has a second pole lug, the second pole lug is located on one side of the at least one first through hole in the second direction, and the second pole lug and the at least one first through hole are spaced apart in the second direction.

[0011] In a possible implementation manner, the first current collector has a first pole tab, and the first pole tab and the second pole tab are spaced apart in the first direction.

[0012] In a possible implementation manner, the first pole lug and the second pole lug are located on the same side of the composite pole piece in the second direction, and the first pole lug and the second pole lug are spaced apart in the third direction.

[0013] In a possible implementation manner, the composite electrode sheet further includes a third current collector, a third electrode material layer and a fourth electrode material layer, the third current collector and the second current collector are respectively located on opposite sides of the first current collector, the third current collector, the third electrode material layer and the fourth electrode material layer are located on the same side of the first current collector, and the first current collector, the third electrode material layer, the third current collector and the fourth electrode material layer are stacked in sequence;

[0014] The third current collector has at least one second through hole, and the at least one second through hole penetrates the third current collector along the first direction. The orthographic projection of the third electrode material layer and / or the fourth electrode material layer on the third current collector covers the at least one second through hole.

[0015] In a possible implementation manner, the third current collector has a third pole tab, and the third pole tab is spaced apart from the first pole tab and the second pole tab in the first direction.

[0016] In a possible implementation manner, the first pole lug, the second pole lug and the third pole lug are located on the same side of the composite pole piece in the second direction, and the first pole lug, the second pole lug and the third pole lug are spaced apart in the third direction.

[0017] In a possible implementation manner, orthographic projections of the second pole tab and the third pole tab on a plane perpendicular to the first direction overlap.

[0018] In a possible implementation manner, a particle size D50 of the material in the first electrode material layer is greater than a particle size D50 of the material in the second electrode material layer.

[0019] In a second aspect, the present application further provides a battery, comprising the composite pole piece described in any one embodiment of the first aspect.

[0020] In a possible implementation manner, the composite electrode sheet is a positive electrode sheet, and / or the composite electrode sheet is a negative electrode sheet.

[0021] In the third aspect, the present application also provides an electrical device, comprising a battery management system and a battery as described in any one embodiment of the second aspect, wherein the battery management system is electrically connected to the battery, and the battery management system is used to control the connectivity and disconnection of the circuit in which the battery is located.

[0022] In the composite electrode provided by the present application, when the electrolyte infiltrates the electrode material from the side of the electrode material away from the first current collector toward the first current collector, the second current collector is located on the infiltration path of the electrolyte. Since the second current collector has multiple first through holes, the electrolyte can pass through the second current collector through the first through holes, thereby ensuring the normal diffusion of lithium ions from the diaphragm to the first current collector; at the same time, the second current collector is located between the side of the electrode material away from the first current collector and the first current collector. The diffusion path of lithium ions from the diaphragm to the second current collector is shorter than the diffusion path of lithium ions from the diaphragm to the first current collector. When the loop where the second pole ear of the second current collector is located is used, the diffusion path of lithium ions can be shortened, the diffusion efficiency of lithium ions can be improved, and the battery performance can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is a cross-sectional view of a composite pole piece with two current collectors provided in an embodiment of the present application;

[0025] Figure 2 is a top view of a second current collector provided in an embodiment of the present application;

[0026] Figure 3 yes Figure 1A schematic diagram of the structure of a composite pole piece provided in the embodiment shown;

[0027] Figure 4 yes Figure 1 A top view of a composite pole piece provided in the illustrated embodiment;

[0028] Figure 5 is a cross-sectional view of a composite pole piece with three current collectors provided in an embodiment of the present application;

[0029] Figure 6 yes Figure 5 A schematic diagram of the structure of a composite pole piece provided in the embodiment shown;

[0030] Figure 7 is a cross-sectional view of a composite pole piece, a common pole piece and a diaphragm provided in an embodiment of the present application;

[0031] Figure 8 4 is a top view of a battery provided in an embodiment of the present application.

[0032] Description of reference numerals:

[0033] 10-composite pole piece, 20-ordinary pole piece, 30-diaphragm, 40-shell;

[0034] 11-a first current collector, 111-a first electrode tab;

[0035] 12-second current collector, 121-second electrode tab, 122-first through hole;

[0036] 13-third current collector, 131-second through hole, 132-third pole ear;

[0037] 14-electrode material, 141-first electrode material layer, 142-second electrode material layer, 143-third electrode material layer, 144-fourth electrode material layer;

[0038] 21-ordinary current collector, 22-ordinary electrode material, 23-ordinary electrode tab. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there can be a central component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there can be a central component at the same time.

[0041] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this application and in the specification are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this application includes any and all combinations of one or more of the related listed items.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0044] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0045] The present application embodiment provides a composite electrode 10, see Figure 1 and Figure 2 The composite pole piece 10 includes a first current collector 11, an electrode material 14 and a second current collector 12. The first current collector 11 includes two opposite surfaces. The electrode material 14 is attached to at least one surface of the first current collector 11, so that the electrode material 14 is arranged on at least one side of the first current collector 11.

[0046] The second current collector 12 is located between the first current collector 11 and the first current collector 11 in the first direction (eg Figure 1On one side of the composite electrode 10 (in the Z direction), the second current collector 12 is parallel to the first current collector 11, so that the second current collector 12 and the first current collector 11 are arranged at intervals, and any point on the second current collector 12 is at the same distance from the first current collector 11 in the first direction, so as to ensure that the diffusion efficiency of lithium ions at various positions on the second current collector 12 or the first current collector 11 along the first direction or the reverse direction of the first direction is the same, which is beneficial to improve the utilization rate of the composite electrode 10. The orthographic projections of the second current collector 12 and the first current collector 11 on the plane perpendicular to the first direction can completely overlap, and the correspondence between the first current collector 11 and the second current collector 12 is good, so that ion exchange can be achieved at various positions on the first current collector 11 and the second current collector 12, which is beneficial to improve the utilization rate of the first current collector 11 and the second current collector 12.

[0047] The electrode material 14 includes a first electrode material layer 141 and a second electrode material layer 142. The second current collector 12, the first electrode material layer 141 and the second electrode material layer 142 are located on the same side of the first current collector 11 in the first direction. In the first direction, the first current collector 11, the first electrode material layer 141, the second current collector 12 and the second electrode material layer 142 are stacked in sequence. When the electrolyte infiltrates the composite electrode sheet 10, the electrolyte infiltration path starts from the side of the second electrode material layer 142 away from the second current collector 12, and passes through the second electrode material layer 142, the second current collector 12, the first electrode material layer 141 and the first current collector 11 in sequence.

[0048] The second current collector 12 has at least one first through hole 122, and at least one first through hole 122 penetrates the second current collector 12 from the first direction, so that when the electrolyte infiltrates the composite pole piece 10, it can pass through the second current collector 12 through at least one first through hole 122, shortening the path of the electrolyte through the second current collector 12, which is conducive to improving the infiltration speed of the electrolyte to the composite pole piece 10, thereby improving the diffusion efficiency of lithium ions and improving the performance of the battery. If the second current collector 12 is not provided with a through hole structure, the electrolyte needs to bypass the second current collector 12 to reach the first current collector 11, or most of the electrolyte is blocked by the second current collector 12 and cannot smoothly reach the first current collector 11, which greatly affects the diffusion efficiency of the electrolyte and thus affects the battery performance.

[0049] The first current collector 11 has a first electrode material layer 141 and a second electrode material layer 142 on one side in the first direction, which ensures the thickness of the electrode material 14, and further ensures the energy density of the battery made of the composite electrode sheet 10. The thickness of the single-layer first electrode material layer 141 or the single-layer second electrode material layer 142 is smaller than the total thickness of the first electrode material layer 141 and the second electrode material layer 142, and the diffusion path of the electrolyte is reduced, so that the time required for the electrolyte to infiltrate the single-layer first electrode material layer 141 or the single-layer second electrode material layer 142 is less than the time required for the electrolyte to infiltrate both the first electrode material layer 141 and the second electrode material layer 142. The second current collector 12 is arranged between the first electrode material layer 141 and the second electrode material layer 142, so that the diffusion path of the electrolyte from the side of the second electrode material layer 142 away from the second current collector 12 to the second current collector 12 is shorter, and the time required for diffusion is reduced; similarly, the electrolyte only needs to pass through the first electrode material layer 141 from the second current collector 12 to the first current collector 11 through the first electrode material layer 141. The diffusion path of the electrolyte is shorter and the time required for diffusion is reduced, which is beneficial to improving the diffusion efficiency of lithium ions and thus improving battery performance.

[0050] The first current collector 11 and the second current collector 12 are respectively located in two independent circuits. When the power demand is high, the circuit where the first current collector 11 is located and the circuit where the second current collector 12 is located can be used for energy supply at the same time. Since the diffusion efficiency of lithium ions is enhanced, it is beneficial to improve the power supply performance; when the power demand is low, only one of the circuit where the first current collector 11 is located and the circuit where the second current collector 12 is located can be used for energy supply. The circuit where the first current collector 11 is located requires the electrolyte to simultaneously infiltrate the first electrode material layer 141 and the second electrode material layer 142. Therefore, the power supply efficiency of the circuit where the first current collector 11 is located is relatively low, but the energy density is relatively high. The circuit where the second current collector 12 is located only requires the electrolyte to simultaneously infiltrate the second electrode material layer 142. Therefore, the power supply efficiency of the circuit where the second current collector 12 is located is relatively high, but the energy density is relatively low, so that the composite electrode 10 can meet the needs of different application scenarios.

[0051] The orthographic projection of the first electrode material layer 141 and / or the second electrode material layer 142 on the second current collector 12 covers at least one first through hole 122, so that the first through hole 122 can serve as a channel to connect the first electrode material layer 141 and the second electrode material layer 142, thereby ensuring that the first through hole 122 has the effect of shortening the diffusion path of the electrolyte from the second electrode material layer 142 to the first electrode material layer 141.

[0052] In one embodiment, the orthographic projections of the first electrode material layer 141 and the second electrode material layer 142 on the second current collector 12 cover all the first through holes 122, thereby ensuring the utilization rate of the first through holes 122, and facilitating increasing the channel area formed by the first through holes 122 between the first electrode material layer 141 and the second electrode material layer 142, thereby ensuring the diffusion efficiency of the electrolyte.

[0053] The present application provides a composite pole piece 10, which includes a first current collector 11, a second current collector 12, a first electrode material layer 141 and a second electrode material layer 142. The second current collector 12, the first electrode material layer 141 and the second electrode material layer 142 are located on the same side of the first current collector 11 in the first direction, thereby ensuring the thickness of the electrode material 14 on one side of the first current collector 11 in the first direction, which is beneficial to ensuring the energy density of the composite pole piece 10.

[0054] In the first direction, the first current collector 11, the first electrode material layer 141, the second current collector 12 and the second electrode material layer 142 are stacked in sequence, and the second current collector 12 has at least one first through hole 122. The second current collector 12 is located between the first electrode material layer 141 and the second electrode material layer 142, so that the first through hole 122 forms a channel for the electrolyte to reach the first electrode material layer 141 from the second electrode material layer 142, shortening the diffusion path of the electrolyte from the second electrode material layer 142 to the first electrode material layer 141, which is beneficial to improving the diffusion efficiency of the electrolyte on the path from the second electrode material layer 142 to the first current collector 11.

[0055] At the same time, the thickness of the second electrode material layer 142 is smaller than the overall thickness of the first electrode material layer 141 and the second electrode material layer 142, so that the diffusion path of the electrolyte through the second electrode material layer 142 to the second current collector 12 is smaller, and has better diffusion efficiency. The circuit where the second current collector 12 is located can be used for energy supply, which is beneficial to improving power supply efficiency. Similarly, the thickness of the first electrode material layer 141 is smaller than the overall thickness of the first electrode material layer 141 and the second electrode material layer 142, so that the diffusion path of the electrolyte through the first electrode material layer 141 to the first current collector 11 is smaller, and has better diffusion efficiency. The circuit where the first current collector 11 is located can be used for energy supply, which is beneficial to improving power supply efficiency.

[0056] For a possible implementation, see Figure 2 , the number of the first through holes 122 is at least two. It can be understood that when the second current collector 12 has more first through holes 122, the channel area formed by the first through holes 122 in the first electrode material layer 141 and the second electrode material layer 142 is larger, the electrolyte is easier to pass through the second current collector 12 from the first through holes 122, and the diffusion efficiency of the electrolyte is higher.

[0057] At least two first through holes 122 are arranged in an array on the second current collector 12, so that the distribution of the at least two first through holes 122 on the second current collector 12 is more regular, which is conducive to simplifying the setting process of the first electrode material layer 141 and the second electrode material layer 142 on the two opposite surfaces of the second current collector 12, so that the first electrode material layer 141 and the second electrode material layer 142 can cover more first through holes 122, thereby enhancing the effect of the first through holes 122 on the diffusion speed of the electrolyte.

[0058] The minimum distance between two adjacent first through holes 122 is 150μm-900μm, and the minimum distance between the center points of two adjacent first through holes 122 is Q. The first through holes 122 satisfy the relationship: 150μm≤Q≤900μm. The above minimum distance is calculated as the distance between the center points of the two first through holes 122. By making the first through holes 122 satisfy the relationship, the spacing distance between two adjacent first through holes 122 is reasonably configured, and the distribution range of at least two first through holes 122 on the second current collector 12 is more reasonable, which is conducive to simplifying the arrangement of the first electrode material layer 141 and the second electrode material layer 142 on the two opposite surfaces of the second current collector 12, and ensuring the utilization rate of at least two first through holes 122. When the value exceeds the above relationship, the spacing between two adjacent first through holes 122 is larger, and the distribution of at least two first through holes 122 on the second current collector 12 is relatively loose. If the number of the first through holes 122 is not increased, the effect of the first through holes 122 on improving the diffusion efficiency of the electrolyte may be affected. At the same time, the first electrode material layer 141 or the second electrode material layer 142 is likely to cover only part of the first through holes 122, resulting in a decrease in the utilization rate of the first through holes 122, thereby reducing the diffusion efficiency of the electrolyte. When the value is lower than the above relationship, the spacing between two adjacent first through holes 122 is smaller, and the distribution of at least two first through holes 122 on the second current collector 12 is relatively dense, resulting in a smaller distribution range of the at least two first through holes 122, a smaller range area in which the second current collector 12 can improve the diffusion efficiency of the electrolyte, and a poorer effect of at least two first through holes 122 on improving the diffusion efficiency of the electrolyte.

[0059] For a possible implementation, see Figure 2 The shape of the first through hole 122 can be set according to actual needs to meet the needs of different application scenarios. The shape of the first through hole 122 includes but is not limited to a circle, a rectangle, and a pentagon.

[0060] In one embodiment, the shape of the first through hole 122 is circular, which is conducive to simplifying the setting of the first through hole 122. The diameter of the first through hole 122 is 50μm-400μm. With the diameter of the first through hole 122 as R, the first through hole 122 satisfies the relationship: 50μm≤R≤400μm. By making the first through hole 122 satisfy the relationship, the size of the first through hole 122 is reasonably set, ensuring that the first through hole 122 has a sufficient area to improve the diffusion efficiency of the electrolyte and ensure the structural strength of the second current collector 12. If it exceeds the above relationship, the size of the first through hole 122 is too large, the structural strength of the second current collector 12 is reduced, and the second current collector 12 is easily damaged, affecting the manufacturing yield and service life of the composite electrode sheet 10; if it is lower than the above relationship, the size of the first through hole 122 is too small, the area of ​​the first through hole 122 is small, and it is difficult for the electrolyte to diffuse between the first electrode material layer 141 or the second electrode material layer 142 through the first through hole 122, resulting in low diffusion efficiency of the electrolyte.

[0061] For a possible implementation, see Figure 1 and Figure 2 , the second direction (such as Figure 1 and Figure 2 X direction) and the third direction (such as Figure 2 The Y direction in the middle) is perpendicular to the first direction (such as Figure 1 The second direction is perpendicular to the third direction, and at least one first through hole 122 is spaced from the edge of the second current collector 12 on at least one side in the second direction, that is, at least one first through hole 122 can be spaced from the edge of the second current collector 12 on a single side in the second direction, or at least one first through hole 122 can be spaced from the edge of the second current collector 12 on both sides opposite to each other in the second direction, so that at least one first through hole 122 has a spacing distance from the edge of the second current collector 12 on at least one side in the second direction, thereby reserving space for the arrangement of the upper ear of the second current collector 12.

[0062] The at least one first through hole 122 may be spaced apart from the edge of the second current collector 12 in the third direction, or the at least one first through hole 122 may be located at the edge of the second current collector 12 in the third direction.

[0063] The minimum distance between at least one first through hole 122 and the edge of the second current collector 12 in the second direction is greater than the minimum distance between at least one first through hole 122 and the edge of the second current collector 12 in the third direction. The minimum distance between at least one first through hole 122 and the edge of the second current collector 12 in the second direction is L1, and the minimum distance between at least one first through hole 122 and the edge of the second current collector 12 in the third direction is L2. At least one first through hole 122 and the second current collector 12 satisfy the relationship: L2≤L1.

[0064] By making at least one first through hole 122 and the second current collector 12 satisfy the above relationship, space is reserved for the arrangement of the pole ear on the second current collector 12, thereby preventing the first through hole 122 from affecting the arrangement of the pole ear on the second current collector 12, reducing the length of the second current collector 12 in the third direction, reducing the area of ​​the positive projection of the second current collector 12 on the plane perpendicular to the first direction, and reducing the volume of the second current collector 12, which is beneficial to reducing the volume of the composite pole piece 10 and realizing the miniaturization of the composite pole piece 10.

[0065] In one embodiment, see Figure 2 , at least one first through hole 122 has a spacing distance from the edge of the second current collector 12 on both sides in the second direction, at least one first through hole 122 has a spacing distance from the edge of the second current collector 12 on both sides in the third direction, and the minimum distance between at least one first through hole 122 and the edge of the second current collector 12 in the second direction is greater than the minimum distance between at least one first through hole 122 and the edge of the second current collector 12 in the third direction, which reserves space for the arrangement of the pole ear on the second current collector 12, and appropriately reduces the volume of the second current collector 12, which is conducive to miniaturization of the composite pole piece 10. At the same time, at least one first through hole 122 and the surrounding edges of the second current collector 12 are reserved with a certain spacing distance, which is conducive to simplifying the arrangement of the first electrode material layer 141 and the second electrode material layer 142 on the second current collector 12, and at least one first through hole 122 is concentrated in the middle area of ​​the second current collector 12, so that the second current collector 12 has a certain structural strength at the surrounding edges, which is also conducive to ensuring the overall structural strength of the second current collector 12 and improving the service life of the second current collector 12.

[0066] For a possible implementation, see Figure 2 and Figure 3 The second current collector 12 has a second pole ear 121, and the second pole ear 121 is located at at least one first through hole 122 in the second direction (such as Figure 2 and Figure 3 On one side of the second electrode tab 121 (in the X direction), the second electrode tab 121 may protrude in the second direction compared to the second current collector 12 body having at least one first through hole 122, that is, the second current collector 12 leads out the second electrode tab 121, so that the second current collector 12 forms a separate loop.

[0067] The second pole lug 121 and at least one first through hole 122 are spaced apart in the second direction to avoid the first through hole 122 affecting the structural strength of the second pole lug 121 itself, and also to avoid the first through hole 122 affecting the structural strength of the connection between the second pole lug 121 and the body of the second current collector 12, which is beneficial to improving the service life of the second current collector 12.

[0068] The second electrode tab 121 is arranged in the second direction and the third direction (eg Figure 2 and Figure 3 The length in the Y direction) can be set according to actual needs. In one embodiment, the length of the second pole ear 121 in the second direction is 1 / 6 to 1 / 3 of the total length of the second current collector 12 in the second direction, and the length of the second pole ear 121 in the third direction is 1 / 4 to 3 / 4 of the total length of the second current collector 12 in the third direction.

[0069] For a possible implementation, see Figure 3 and Figure 4 The first current collector 11 has a first electrode tab 111. Since the first electrode material layer 141 is located between the first current collector 11 and the second current collector 12, the first electrode material layer 141 has a certain thickness, so that the first current collector 11 and the second current collector 12 are in the first direction (such as Figure 3 The first pole tab 111 and the second pole tab 121 are spaced apart in the first direction.

[0070] The first pole ear 111 is led out from the first current collector 11, and the second pole ear 121 is led out from the second current collector 12. The first current collector 11 and the second current collector 12 are respectively located in two independent loops. By arranging the first pole ear 111 and the second pole ear 121 at intervals in the first direction, the contact between the first pole ear 111 and the second pole ear 121 is avoided, which is conducive to the first current collector 11 and the second current collector 12 forming two independent loops respectively. The composite pole piece 10 can select the loop where the first current collector 11 and / or the second current collector is located according to different application scenarios.

[0071] The first pole tab 111 and the second pole tab 120 may be located at the second direction (eg Figure 3 and Figure 4 The first pole ear 111 and the second pole ear 121 may also be located on the same side of the composite pole piece 10 in the second direction, and the present application does not limit this.

[0072] In one embodiment, see Figure 4 The first pole ear 111 and the second pole ear 121 are located on the same side of the composite pole piece 10 in the second direction, and the first pole ear 111 and the second pole ear 121 are located in the third direction (such as Figure 3 and Figure 4The first pole tab 111 and the second pole tab 121 are spaced apart in the first direction and the third direction, further avoiding contact between the first pole tab 111 and the second pole tab 121, which is conducive to the first current collector 11 and the second current collector 12 forming two independent loops. At the same time, the first pole tab 111 and the second pole tab 121 are more easily distinguished, which is conducive to simplifying the selection process of the first pole tab 111 and the second pole tab 121.

[0073] For a possible implementation, see Figure 5 The composite pole piece 10 also includes a third current collector 13, a third electrode material layer 143 and a fourth electrode material layer 144. The third current collector 13, the third electrode material layer 143 and the fourth electrode material layer 144 are located on the same side of the first current collector 11, and the third current collector 13 and the second current collector 12 are respectively located on opposite sides of the first current collector 11.

[0074] The two opposite surfaces of the first current collector 11 are connected to the first electrode material layer 141 and the third electrode material layer 143 respectively, and the third current collector 13 is located between the third electrode material layer 143 and the fourth electrode material layer 144, so that in the first direction (such as Figure 5 In the middle Z direction), the fourth electrode material layer 144, the third current collector 13, the third electrode material layer 143, the first current collector 11, the first electrode material layer 141, the second current collector 12 and the second electrode material layer 142 are stacked in sequence.

[0075] When the electrolyte infiltrates the composite electrode sheet 10, the electrolyte includes two infiltration paths. One infiltration path starts from the side of the second electrode material layer 142 away from the second current collector 12, passes through the second electrode material layer 142, the second current collector 12 and the first electrode material layer 141 in sequence, and finally reaches the first current collector 11; the other infiltration path starts from the side of the fourth electrode material layer 144 away from the third current collector 13, passes through the fourth electrode material layer 144, the third current collector 13 and the third electrode material layer 143 in sequence, and finally reaches the first current collector 11.

[0076] The electrolyte can infiltrate the composite electrode 10 along a first direction, and the electrolyte can also infiltrate the composite electrode 10 in the opposite direction of the first direction, so that the infiltration path of the electrolyte to the composite electrode 10 in a single direction is shortened, which is beneficial to improving the infiltration speed of the electrolyte to the composite electrode 10, thereby improving the diffusion efficiency of lithium ions.

[0077] The third current collector 13 has at least one second through hole 131, and at least one second through hole 131 penetrates the third current collector 13 along the first direction, so that when the electrolyte infiltrates the composite electrode 10, it can pass through the third current collector 13 through at least one second through hole 131, shortening the path of the electrolyte through the third current collector 13, which is conducive to improving the infiltration speed of the electrolyte to the composite electrode 10, thereby improving the diffusion efficiency of lithium ions and improving the performance of the battery. If the third current collector 13 is not provided with a through hole structure, the electrolyte needs to bypass the third current collector 13 to reach the first current collector 11, or most of the electrolyte is blocked by the third current collector 13 and cannot smoothly reach the first current collector 11, which greatly affects the diffusion efficiency of the electrolyte and thus affects the battery performance.

[0078] The first current collector 11 has a third electrode material layer 143 and a fourth electrode material layer 144 on one side in the first direction, which further increases the overall thickness of the electrode material 14 and ensures the energy density of the battery made of the composite electrode sheet 10. The thickness of the single-layer third electrode material layer 143 or the single-layer fourth electrode material layer 144 is smaller than the total thickness of the third electrode material layer 143 and the fourth electrode material layer 144, and the diffusion path of the electrolyte is reduced, so that the time required for the electrolyte to infiltrate the single-layer third electrode material layer 143 or the single-layer fourth electrode material layer 144 is less than the time required for the electrolyte to infiltrate both the third electrode material layer 143 and the fourth electrode material layer 144. The third current collector 13 is arranged between the third electrode material layer 143 and the fourth electrode material layer 144, so that the diffusion path of the electrolyte from the side of the fourth electrode material layer 144 away from the third current collector 13 to the third current collector 13 is shorter, and the time required for diffusion is reduced; similarly, the electrolyte only needs to pass through the third electrode material layer 143 from the third current collector 13 to the first current collector 11 through the third electrode material layer 143. The diffusion path of the electrolyte is shorter and the time required for diffusion is reduced, which is beneficial to improving the diffusion efficiency of lithium ions and thus improving battery performance.

[0079] The first current collector 11, the second current collector 12 and the third current collector 13 are respectively located in three independent circuits. When the power demand is high, the circuit where the first current collector 11 is located, the circuit where the second current collector 12 is located and the circuit where the third current collector 13 is located can be used for energy supply at the same time, or any two circuits of the circuit where the first current collector 11 is located, the circuit where the second current collector 12 is located and the circuit where the third current collector 13 is located can be used for energy supply; when the power demand is low, only one of the circuits where the first current collector 11 is located, the circuit where the second current collector 12 is located and the circuit where the third current collector 13 is located can be used for energy supply, so that the composite pole piece 10 can meet the needs of different application scenarios.

[0080] The orthographic projection of the third electrode material layer 143 and / or the fourth electrode material layer 144 on the third current collector 13 covers at least one second through hole 131, so that the second through hole 131 can serve as a channel to connect the third electrode material layer 143 and the fourth electrode material layer 144, thereby ensuring that the second through hole 131 has the effect of shortening the diffusion path of the electrolyte from the fourth electrode material layer 144 to the third electrode material layer 143.

[0081] It is understandable that the composite pole piece 10 may also include four or more current collectors to achieve a greater number of loops, and except for the first current collector 11, other current collectors are provided with corresponding through holes to ensure the electrolyte's wetting effect on the composite pole piece 10. However, when the thickness of the composite pole piece 10 is too large, although the energy density increases, the time required for the electrolyte to completely infiltrate the composite pole piece 10 also increases, and it is not possible to achieve a better power supply effect by increasing the number of current collectors.

[0082] In one embodiment, the thickness of the first current collector 11 is 3 μm-16 μm, the thickness of the second current collector 12 is 3 μm-15 μm, and the thickness of the third current collector 13 is equal to the thickness of the second current collector 12 .

[0083] For a possible implementation, see Figure 5 and Figure 6 , the third current collector 13 has a third electrode tab 132. Since the third electrode material layer 143 is located between the first current collector 11 and the third current collector 13, the third electrode material layer 143 has a certain thickness, so that the first current collector 11 and the third current collector 13 are in the first direction (such as Figure 5 and Figure 6 The first pole tab 111 and the third pole tab 132 are spaced apart in the first direction. The first pole tab 111 and the second pole tab 121 are spaced apart in the first direction, and the second current collector 12 and the third current collector 13 are respectively located on opposite sides of the first current collector 11 in the first direction, so that the third pole tab 132, the first pole tab 111 and the second pole tab 121 are spaced apart in sequence in the first direction.

[0084] The first pole ear 111 is led out from the first current collector 11, the second pole ear 121 is led out from the second current collector 12, and the third pole ear 132 is led out from the third current collector 13. The first current collector 11, the second current collector 12 and the third current collector 13 are respectively located in three independent loops. By arranging the third pole ear 132, the first pole ear 111 and the second pole ear 121 in sequence in the first direction, contact between the third pole ear 132, the first pole ear 111 and the second pole ear 121 is avoided, which is conducive to the first current collector 11, the second current collector 12 and the third current collector 13 forming three independent loops respectively. The composite pole piece 10 can select different loop combinations according to different application scenarios.

[0085] The first pole tab 111, the second pole tab 121 and the third pole tab 132 may be located at the second direction (eg Figure 5 and Figure 6 The first pole ear 111, the second pole ear 121 and the third pole ear 132 may also be distributed on the opposite sides of the composite pole piece 10 in the second direction, and the present application does not limit this.

[0086] In one embodiment, see Figure 6 , the first pole ear 111, the second pole ear 121 and the third pole ear 132 are located on the same side of the composite pole piece 10 in the second direction, and the first pole ear 111 and the second pole ear 121 and the third pole ear 132 are all in the third direction (such as Figure 6 The second pole lug 121 and the third pole lug 132 are arranged at intervals in the Y direction, so that in the third direction, the second pole lug 121 and the third pole lug 132 are located on the same side, and the first pole lug 111 is located on a separate side, further avoiding the first pole lug 111, the second pole lug 121 and the third pole lug 132 from contacting each other, which is conducive to the first current collector 11, the second current collector 12 and the third current collector 13 to form three independent loops respectively. At the same time, the second pole lug 121 and the third pole lug 132 located on the same side are both led out from the current collector with a through hole, and the first pole lug 111 located on the other side is led out from the current collector without a through hole, so that the pole lugs led out from the current collector with a through hole and the pole lugs led out from the current collector without a through hole are easier to distinguish.

[0087] In one embodiment, see Figure 6 The orthographic projections of the second pole ear 121 and the third pole ear 132 on the plane perpendicular to the first direction overlap, so that the second pole ear 121 and the third pole ear 132 in the composite pole piece 10 have a better corresponding relationship, simplifying the distinction between the second pole ear 121 and the third pole ear 132; at the same time, it avoids the second pole ear 121 or the third pole ear 132 from being too protruding, which is conducive to the miniaturization of the composite pole piece 10.

[0088] For a possible implementation, see Figure 1 and Figure 5 The particle size D50 of the material in the first electrode material layer 141 is greater than the particle size D50 of the material in the second electrode material layer 142 . The particle size here refers to the particle size of the material in the first electrode material layer 141 or the second electrode material layer 142 .

[0089] When the electrolyte infiltrates from the side of the electrode material 14 away from the first current collector 11 toward the first current collector 11, the electrolyte first infiltrates the second electrode material layer 142, then passes through the second current collector 12, and then infiltrates the first electrode material layer 141. The particle size D50 of the first electrode material layer 141 is greater than the particle size D50 of the second electrode material layer 142, so that the surface density of the first electrode material layer 141 and the second electrode material layer 142, and the compaction density of the first electrode material layer 141 and the second electrode material layer 142 are both in a suitable state, the energy density of the first electrode material layer 141 is greater than the energy density of the second electrode material layer 142, and the rate performance of the second electrode material layer 142 is greater than the rate performance of the first electrode material layer 141, that is, the first electrode material layer 141 is an energy-type electrode material 14 layer, and the second electrode material layer 142 is a power-type electrode material 14 layer.

[0090] The first electrode material layer 141 can be formed by large-particle electrode material 14, or the first electrode material layer 141 can be formed by mixing large-particle electrode material 14 and small-particle electrode material 14. The small-particle electrode material 14 can fill the gaps in the large particles, which is beneficial to increase the compaction density of the first electrode material layer 141, thereby improving the energy density of the first electrode material layer 141; the second electrode material layer 142 can be formed by small-particle electrode material 14, so that the compaction density of the second electrode material layer 142 is smaller than the compaction density of the first electrode material 14, and the electrolyte infiltration efficiency in the second electrode material layer 142 is higher, thereby improving the rate performance of the second electrode material layer 142.

[0091] When the power demand is low, only the circuit where the first current collector 11 is used for energy supply, and the lithium ions can smoothly pass through the second electrode material layer 142 and the first electrode material layer 141, and both the first electrode material layer 141 and the second electrode material layer 142 can perform their functions; when the power demand is high, only the circuit where the second current collector 12 is used for energy supply, or the circuit where the first current collector 11 and the circuit where the second current collector 12 are used for energy supply at the same time, which can effectively shorten the diffusion path of lithium ions and effectively use the energy-type first electrode material layer 141 and the power-type second electrode material layer 142.

[0092] Lithium deposition usually occurs on the surface of the electrode, so that the power-type second electrode material layer 142 is located on the surface of the composite electrode 10, so that the surface of the composite electrode 10 has an electrode material 14 layer with a lower compaction density, which is beneficial to improve the wetting efficiency of the electrolyte, shorten the diffusion path of lithium ions, and thus reduce the risk of lithium deposition.

[0093] At the same time, the energy-type first electrode material layer 141 is sandwiched between the first current collector 11 and the second current collector 12 , so that the diffusion path of lithium ions at the first electrode material layer 141 is shortened, which is beneficial to improving the rate performance of the first electrode material layer 141 .

[0094] This application also provides a battery, see Figure 5 , Figure 7 and Figure 8 The battery includes the composite pole piece 10 described in any of the above embodiments. Depending on the different materials of the first current collector 11, the second current collector 12, the first electrode material layer 141 and the second electrode material layer 142, the composite pole piece 10 can be a negative pole piece or a positive pole piece.

[0095] In one embodiment, see Figure 5 and Figure 7 The battery also includes a housing 40, a diaphragm 30 and a common pole piece 20, wherein the common pole piece 20, the diaphragm 30 and the composite pole piece 10 are arranged in a first direction (such as Figure 7 The housing 40 encloses the common electrode sheet 20, the diaphragm 30 and the composite electrode sheet 10. When the composite electrode sheet 10 is a negative electrode sheet, the common electrode sheet 20 is a positive electrode sheet in which the current collector is not provided with a through hole; when the composite electrode sheet 10 is a positive electrode sheet, the common electrode sheet 20 is a negative electrode sheet in which the current collector is not provided with a through hole.

[0096] In one embodiment, see Figure 5 and Figure 7 The composite electrode sheet 10 is a negative electrode sheet, and the composite electrode sheet 10 includes a first current collector 11, a second current collector 12, and a third current collector 13. The common electrode sheet 20 is a positive electrode sheet, and the common electrode sheet 20 includes a common current collector 21 and a common electrode material 22, and the common electrode material 22 is located on two surfaces of the common current collector 21 that are opposite to each other in the first direction. The common electrode sheet 20 forms a first loop, a second loop, and a third loop with the first current collector 11, the second current collector 12, and the third current collector 13, respectively. The battery can select at least one of the first loop, the second loop, and the third loop to realize power supply to meet different application requirements.

[0097] In one embodiment, see Figure 8 The composite electrode 10 includes a first electrode tab 111, a second electrode tab 121 and a third electrode tab 132 (not shown). Figure 8 The first pole ear 111, the second pole ear 121 and the third pole ear 132 are all negative pole ears, the common pole sheet 20 is a positive pole sheet, the common pole sheet 20 leads to the common pole ear 23, and the common pole ear 23 is a positive pole ear. The positive pole ear and the negative pole ear are respectively located in the second direction (such as Figure 8The first pole ear 111, the second pole ear 121 and the third pole ear 132 are located on the same side of the battery in the second direction, and the common pole ear 23 is located on the other side of the battery in the second direction, which is beneficial to avoid short circuit caused by contact between the positive pole ear and the negative pole ear and simplifies the distinction between the positive pole ear and the negative pole ear.

[0098] The present application also provides an electrical device, which includes a battery management system (BMS) and a battery described in any one of the above embodiments, the battery management system and the battery are electrically connected, and the battery management system is used to control the connectivity and disconnection of the circuit where the battery is located, that is, the battery management system can be used to control at least one of the first circuit, the second circuit and the third circuit to realize power supply to meet different application requirements.

[0099] It can be understood that the electrical equipment in this embodiment has the battery in the above embodiment. Therefore, the electrical equipment in this embodiment has all the technical effects of the battery in the above embodiment. Since the technical effects of the battery have been fully explained in the above embodiment, they will not be repeated here.

[0100] In the description of this specification, the description with reference to the terms "embodiment", "specific embodiment", "example" or "specific example" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0101] What is disclosed above is only a preferred embodiment of the present application, and it certainly cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiment and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A composite pole piece, characterized in that: include: First Collector Fluid; A first electrode material layer and a second electrode material layer are disposed on the same side of the first current collector; A second current collector is arranged between the first electrode material layer and the second electrode material layer, the first current collector, the first electrode material layer, the second current collector and the second electrode material layer are stacked in sequence in a first direction, the second current collector has at least one first through hole, the at least one first through hole penetrates the second current collector along the first direction, and the orthographic projection of the first electrode material layer and / or the second electrode material layer on the second current collector covers at least one first through hole.

2. The composite pole piece according to claim 1, characterized in that: The number of the first through holes is at least two, and the at least two first through holes are arranged in an array on the second current collector, and the minimum distance between two adjacent first through holes is 150 μm-900 μm.

3. The composite pole piece according to claim 1 or 2, characterized in that: The first through hole is circular in shape, and has a diameter of 50 μm-400 μm.

4. The composite pole piece according to claim 1, characterized in that: The second direction and the third direction are both perpendicular to the first direction, the second direction is perpendicular to the third direction, the at least one first through hole is spaced apart from the edge of the second current collector on at least one side in the second direction, and the minimum distance between the at least one first through hole and the edge of the second current collector in the second direction is greater than the minimum distance between the at least one first through hole and the edge of the second current collector in the third direction.

5. The composite pole piece according to claim 4, characterized in that: The second current collector has a second pole tab, the second pole tab is located on one side of the at least one first through hole in the second direction, and the second pole tab and the at least one first through hole are spaced apart in the second direction.

6. The composite pole piece according to claim 5, characterized in that: The first current collector has a first electrode tab, and the first electrode tab and the second electrode tab are spaced apart in the first direction.

7. The composite pole piece according to claim 6, characterized in that: The first pole tab and the second pole tab are located on the same side of the composite pole piece in the second direction, and the first pole tab and the second pole tab are spaced apart in the third direction.

8. The composite pole piece according to claim 6, characterized in that: The composite electrode sheet further includes a third current collector, a third electrode material layer and a fourth electrode material layer, wherein the third current collector and the second current collector are respectively located on two opposite sides of the first current collector, and the third current collector, the third electrode material layer and the fourth electrode material layer are located on the same side of the first current collector, and the first current collector, the third electrode material layer, the third current collector and the fourth electrode material layer are stacked in sequence; The third current collector has at least one second through hole, and the at least one second through hole penetrates the third current collector along the first direction. The orthographic projection of the third electrode material layer and / or the fourth electrode material layer on the third current collector covers the at least one second through hole.

9. The composite pole piece according to claim 8, characterized in that: The third current collector has a third electrode tab, and the third electrode tab is spaced apart from the first electrode tab and the second electrode tab in the first direction.

10. The composite pole piece according to claim 9, characterized in that: The first pole tab, the second pole tab and the third pole tab are located on the same side of the composite pole piece in the second direction, and the first pole tab, the second pole tab and the third pole tab are all spaced apart in the third direction.

11. The composite pole piece according to claim 10, characterized in that: The orthographic projections of the second pole tab and the third pole tab on a plane perpendicular to the first direction overlap.

12. The composite pole piece according to claim 1, characterized in that: The particle size D50 of the material in the first electrode material layer is greater than the particle size D50 of the material in the second electrode material layer.

13. A battery, characterized in that: A composite pole piece comprising any one of claims 1 to 12.

14. The battery according to claim 13, characterized in that The composite electrode sheet is a positive electrode sheet, and / or the composite electrode sheet is a negative electrode sheet.

15. An electrical equipment, characterized in that: It comprises a battery management system and the battery according to claim 13 or 14, wherein the battery management system is electrically connected to the battery, and the battery management system is used to control the connection and disconnection of the circuit in which the battery is located.

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