Electrode plate structure based on composite current collector, wound core, and battery

Abstract

Disclosed in the present application are an electrode plate structure based on a composite current collector, a wound core, and a battery. The electrode plate structure based on a composite current collector comprises: the composite current collector; and tabs. The wound core comprises a separator and the electrode plate structure based on a composite current collector. A positive electrode plate, the separator and a negative electrode plate are sequentially stacked and wound to form a wound core body. After winding, a first negative tab and a second negative tab are connected to form a negative tab. The battery comprises the wound core.

Description

Electrode structures, winding cores, and batteries based on composite current collectors

[0001] This application claims priority to Chinese Patent Application No. 202422812836.3, filed on November 18, 2024, entitled "An Electrode Structure Based on Composite Current Collector, a Core and a Battery", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to an electrode structure, a winding core, and a battery based on a composite current collector. Background Technology

[0003] Composite current collectors have a "sandwich" structure with metal layers on both sides and a polymer layer in the middle. Due to their advantages such as good safety, lightweight, high toughness, high energy density, and low cost, composite current collectors are gradually entering the industrialization era. However, because the polymer layer in the middle of the composite current collector is non-conductive, welding makes it difficult to achieve conductivity between the upper and lower metal layers, thus preventing effective electron output. Therefore, electrode tab welding is a major technical challenge. Invention Overview

[0004] The tab welding method typically involves using an adapter welding technique within a laminated cell structure. This involves welding metal connecting tabs to the metal layers on both sides of the current collector, and then welding all the connecting tabs together to form an electronic path. However, this adapter welding technique introduces two layers of metal connecting tabs, increasing the weight and cost of the composite current collector structure, and requiring a larger space. This welding method is complex, has low welding efficiency, and is difficult to guarantee in terms of welding quality. Furthermore, it deviates from the goals of lightweight, low-cost, and high-energy-density composite current collectors.

[0005] This application provides an electrode structure based on a composite current collector, wherein the two ends of the electrode tab are respectively connected to one of the first optical foil regions and one of the second optical foil regions to realize the conduction of the composite current collector. This structure is easy to process and facilitates the achievement of lightweight, low cost and high energy density goals.

[0006] This application provides a core, which is formed by sequentially stacking and winding a positive electrode sheet, a separator, and a negative electrode sheet to form the core body. After winding, only the first negative electrode tab and the second negative electrode tab need to be connected to form the negative electrode tab. The overall structure and processing technology are simple, which helps to reduce costs and improve production efficiency.

[0007] This application provides a battery that uses the aforementioned core, with a simple overall structure and processing technology, which helps to reduce costs and improve production efficiency.

[0008] In a first aspect, embodiments of this application provide an electrode structure based on a composite current collector, comprising:

[0009] A composite current collector, wherein a first surface of the composite current collector is alternately provided with a first foil area and a first coating area along its length direction, and a second surface of the composite current collector is alternately provided with a second foil area and a second coating area along its length direction.

[0010] The electrode has one end connected to one of the first foil areas and the other end connected to one of the second foil areas to conduct the composite current collector.

[0011] In one embodiment, the composite current collector includes a first metal layer, an intermediate polymer layer and a second metal layer stacked sequentially, wherein the first metal layer is disposed on a first surface of the intermediate polymer layer and the second metal layer is disposed on a second surface of the intermediate polymer layer.

[0012] The first surface and the second surface of the intermediate polymer layer are two surfaces with opposite positions of the intermediate polymer layer.

[0013] In one embodiment, the first surface and the second surface of the composite current collector are two surfaces with opposite installation positions.

[0014] In one embodiment, a single electrode tab is provided, which is a positive electrode tab and forms a positive electrode plate after being connected to the composite current collector;

[0015] Alternatively, there are two tabs, namely a first negative tab and a second negative tab, which are connected to the composite current collector to form a negative electrode sheet.

[0016] In one embodiment, the first surface of the composite current collector is alternately provided with at least two first coating areas and at least three first foil areas along its length direction, and the second surface of the composite current collector is alternately provided with at least two second coating areas and at least three second foil areas along its length direction.

[0017] One end of the positive electrode tab is welded to the first foil area located in the middle or near the middle position, and the other end of the positive electrode tab is welded to the second foil area located in the middle or near the middle position to conduct the composite current collector.

[0018] In one embodiment, the first surface of the composite current collector is alternately provided with at least one first coating area and at least two first foil areas along its length direction, and the second surface of the composite current collector is alternately provided with at least one second coating area and at least two second foil areas along its length direction.

[0019] One end of the first negative electrode tab is welded to the first foil area located at the head end, and the other end of the first negative electrode tab is welded to the second foil area located at the head end, so as to conduct the composite current collector.

[0020] One end of the second negative electrode tab is welded to the first foil area located at the end position, and the other end of the second negative electrode tab is welded to the second foil area located at the end position to conduct the composite current collector.

[0021] In one embodiment, the overall shape of the electrode is "U" or "V".

[0022] Secondly, embodiments of this application provide a core, including a diaphragm and an electrode structure based on a composite current collector as described above, wherein a positive electrode, a diaphragm, and a negative electrode are sequentially stacked and wound to form a core body.

[0023] After winding, the first negative electrode tab connects with the second negative electrode tab to form a negative electrode tab.

[0024] In one embodiment, the positive electrode tab and the negative electrode tab are respectively disposed on both sides of the core body.

[0025] Thirdly, embodiments of this application provide a battery comprising the aforementioned winding core.

[0026] The effect of this application:

[0027] 1. The electrode structure based on composite current collector in this application has a simple structure. The two ends of the electrode tab are respectively connected to one of the first optical foil regions and one of the second optical foil regions to realize the conduction of composite current collector. It has low processing difficulty and is conducive to achieving the goals of lightweight, low cost and high energy density.

[0028] 2. The core in this application is formed by sequentially stacking and winding a positive electrode sheet, a separator, and a negative electrode sheet to form the core body. After winding, it is only necessary to connect the first negative electrode tab and the second negative electrode tab to form the negative electrode tab. The overall structure and processing technology are simple, which helps to reduce costs and improve production efficiency.

[0029] 3. The battery in this application uses the above-mentioned core, which has a simple overall structure and processing technology, which helps to reduce costs and improve production efficiency. Attached Figure Description

[0030] Figure 1 is a top-view structural schematic diagram of the composite current collector in some implementations of this application;

[0031] Figure 2 is a schematic diagram of the positive electrode sheet from a top view in some implementations of this application;

[0032] Figure 3 is a structural schematic diagram of the positive electrode sheet from a bottom-view perspective in some implementations of this application;

[0033] Figure 4 is a schematic diagram of the positive electrode sheet from a side view in some implementations of this application;

[0034] Figure 5 is a top-view structural diagram of the negative electrode sheet in some implementations of this application;

[0035] Figure 6 is a structural schematic diagram of the negative electrode sheet from a bottom-view perspective in some implementations of this application;

[0036] Figure 7 is a schematic diagram of the negative electrode sheet from a side view in some implementations of this application;

[0037] Figure 8 is a structural schematic diagram of the core from a top-down view in some implementations of this application;

[0038] Figure 9 is a structural schematic diagram of the core from a bottom-up perspective in some implementations of this application;

[0039] Figure 10 is a structural schematic diagram of the core from a side view in some implementations of this application;

[0040] Figure 11 is a schematic diagram of the battery structure in some implementations of this application.

[0041] The meanings of the reference numerals in the attached figures are as follows:

[0042] 10. Composite current collector; 101. First metal layer; 102. Intermediate polymer layer; 103. Second metal layer; 20. First foil area; 30. First coating area; 40. Second foil area; 50. Second coating area; 60. Positive electrode tab; 70. Negative electrode tab; 701. First negative electrode tab; 702. Second negative electrode tab; 80. Positive electrode sheet; 90. Negative electrode sheet; 100. Separator. Embodiments of the present invention

[0043] In the description of this application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.

[0044] Example 1

[0045] Referring to Figures 1-7, this application discloses an electrode structure based on a composite current collector, comprising: a composite current collector 10, wherein a first surface of the composite current collector 10 is alternately provided with a first foil region 20 and a first coating region 30 along its length direction, and a second surface of the composite current collector 10 is alternately provided with a second foil region 40 and a second coating region 50 along its length direction; and an electrode tab, one end of which is connected to one of the first foil regions 20, and the other end of which is connected to one of the second foil regions 40, so as to conduct the composite current collector 10.

[0046] It should be noted that the area on the first surface of the composite current collector 10 coated with slurry forms the first coating area 30, the area on the first surface of the composite current collector 10 not coated with slurry forms the first foil area 20, the area on the second surface of the composite current collector 10 coated with slurry forms the second coating area 50, and the area on the second surface of the composite current collector 10 not coated with slurry forms the second foil area 40. The slurry coated on the first and second surfaces of the composite current collector 10 can be any existing material, for example: the positive electrode slurry includes a positive electrode material, a first conductive agent, a first binder, and the solvent NMP; the mass ratio of the positive electrode material, the first conductive agent, and the first binder is 95~99:1~3.5:0.5~1.5; the negative electrode slurry includes a negative electrode material, a second conductive agent, a second binder, and a solvent; the mass ratio of the negative electrode material, the second conductive agent, and the second binder is 95~99:0.3~2:1~3.5.

[0047] The electrode structure based on the composite current collector in this application has a simple structure. The two ends of the electrode tab are respectively connected to one of the first optical foil regions 20 and one of the second optical foil regions 40, so as to realize the conduction of the composite current collector 10. The processing difficulty is low, which is conducive to achieving the goals of lightweight, low cost and high energy density.

[0048] In this embodiment, the composite current collector 10 includes a first metal layer 101, an intermediate polymer layer 102, and a second metal layer 103 stacked sequentially. The first metal layer 101 is disposed on the first surface of the intermediate polymer layer 102, and the second metal layer 103 is disposed on the second surface of the intermediate polymer layer 102. The first surface and the second surface of the intermediate polymer layer 102 are two surfaces of the intermediate polymer layer 102 with opposite positions.

[0049] Specifically, the composite current collector 10 can be an existing composite current collector 10, the first metal layer 101 is aluminum foil (positive current collector) / copper foil (negative current collector), the middle polymer layer 102 is polyimide (PI) material, and the second metal layer 103 is aluminum foil (positive current collector) / copper foil (negative current collector).

[0050] Specifically, the intermediate polymer layer 102 is sheet-like, and the first surface and the second surface of the intermediate polymer layer 102 are both surfaces with a large surface area, such as the front side and the back side of the intermediate polymer layer 102.

[0051] In the embodiments of this application, the first surface and the second surface of the composite current collector 10 are two surfaces with opposite installation positions of the composite current collector 10.

[0052] Specifically, the composite current collector 10 is sheet-shaped, and the first surface and the second surface of the composite current collector 10 are both surfaces with a larger surface area, such as the front and back surfaces of the composite current collector 10.

[0053] In this embodiment, one electrode is provided, which is a positive electrode 60, and it forms a positive electrode plate 80 after being connected to the composite current collector 10; or, two electrodes are provided, namely a first negative electrode 701 and a second negative electrode 702, which form a negative electrode plate 90 after being connected to the composite current collector 10.

[0054] In other words, by setting the number and position of the tabs and corresponding to the first coating area 30, the first foil area 20, the second coating area 50 and the second foil area 40, the electrode structure based on the composite current collector can obtain a positive electrode 80 or a negative electrode 90.

[0055] Specifically, the positive electrode tab 60 is preferably made of aluminum, and the dimensions of the positive electrode tab 60 are preferably: length * width: 80mm * 5mm; the first negative electrode tab 701 and the second negative electrode tab 702 are preferably made of copper plated with nickel, and the dimensions of the first negative electrode tab 701 and the second negative electrode tab 702 are the same, preferably: length * width: 78mm * 5mm.

[0056] In this embodiment, the first surface of the composite current collector 10 is alternately provided with at least two first coating areas 30 and at least three first foil areas 20 along its length direction, and the second surface of the composite current collector 10 is alternately provided with at least two second coating areas 50 and at least three second foil areas 40 along its length direction; one end of the positive electrode tab 60 is welded to the first foil area 20 located in the middle or near the middle position, and the other end of the positive electrode tab 60 is welded to the second foil area 40 located in the middle or near the middle position, so as to conduct the composite current collector 10.

[0057] Preferably, referring to Figures 2-4, the first surface of the composite current collector 10 is alternately provided with two first coating areas 30 and three first foil areas 20 along its length direction, and the second surface of the composite current collector 10 is alternately provided with two second coating areas 50 and three second foil areas 40 along its length direction. One end of the positive electrode tab 60 is welded to the first foil area 20 located in the middle position, and the other end of the positive electrode tab 60 is welded to the second foil area 40 located in the middle position to conduct the composite current collector 10.

[0058] In this embodiment, the first surface of the composite current collector 10 is alternately provided with at least one first coating area 30 and at least two first foil areas 20 along its length direction, and the second surface of the composite current collector 10 is alternately provided with at least one second coating area 50 and at least two second foil areas 40 along its length direction; one end of the first negative electrode tab 701 is welded to the first foil area 20 located at the beginning position, and the other end of the first negative electrode tab 701 is welded to the second foil area 40 located at the beginning position to conduct the composite current collector 10; one end of the second negative electrode tab 702 is welded to the first foil area 20 located at the end position, and the other end of the second negative electrode tab 702 is welded to the second foil area 40 located at the end position to conduct the composite current collector 10.

[0059] Preferably, referring to Figures 5-7, the first surface of the composite current collector 10 is alternately provided with a first coating area 30 and two first foil areas 20 along its length direction, and the second surface of the composite current collector 10 is alternately provided with a second coating area 50 and two second foil areas 40 along its length direction; one end of the first negative electrode tab 701 is welded to the first foil area 20 located at the beginning position, and the other end of the first negative electrode tab 701 is welded to the second foil area 40 located at the beginning position to conduct the composite current collector 10; one end of the second negative electrode tab 702 is welded to the first foil area 20 located at the end position, and the other end of the second negative electrode tab 702 is welded to the second foil area 40 located at the end position to conduct the composite current collector 10.

[0060] That is, the setting position, setting size and setting quantity of the first coating area 30, the first foil area 20, the second coating area 50 and the second foil area 40 are determined according to the actual application scenario and are not limited.

[0061] In the embodiments of this application, the overall shape of the electrode is "U" or "V".

[0062] That is, the positive electrode tab 60 extends from the first surface of the composite current collector 10 to the second surface of the composite current collector 10, so that one end of the positive electrode tab 60 is welded to the first foil area 20 located in the middle or near the middle position, and the other end of the positive electrode tab 60 is welded to the second foil area 40 located in the middle or near the middle position, so as to conduct the composite current collector 10 to form the positive electrode sheet 80.

[0063] That is, the first negative electrode tab 701 extends from the first surface of the composite current collector 10 to the composite current collector.

[0064] The second surface of the composite current collector 10 is provided so that one end of the first negative electrode tab 701 is welded to the first foil area 20 located at the beginning position and the other end of the first negative electrode tab 701 is welded to the second foil area 40 located at the beginning position to conduct the composite current collector 10; the second negative electrode tab 702 extends from the first surface of the composite current collector 10 to the second surface of the composite current collector 10 so that one end of the second negative electrode tab 702 is welded to the first foil area 20 located at the end position and the other end of the second negative electrode tab 702 is welded to the second foil area 40 located at the end position to conduct the composite current collector 10, thereby forming a negative electrode sheet 90.

[0065] Example 2

[0066] Referring to Figures 1-10, this application discloses a core, including a diaphragm 100 and an electrode structure based on a composite current collector as described above. The positive electrode 80, the diaphragm 100, and the negative electrode 90 are sequentially stacked and wound to form the core body. After winding, the first negative electrode tab 701 and the second negative electrode tab 702 are connected to form the negative electrode tab 70.

[0067] Preferably, the first negative electrode tab 701 and the second negative electrode tab 702 are welded together to form the negative electrode tab 70; of course, the first negative electrode tab 701 and the second negative electrode tab 702 can also be connected in other conductive ways to form the negative electrode tab 70, depending on the actual application scenario, and there is no limitation.

[0068] The core in this application is formed by sequentially stacking and winding the positive electrode sheet 80, the separator 100 and the negative electrode sheet 90. After winding, only the first negative electrode tab 701 and the second negative electrode tab 702 need to be connected to form the negative electrode tab 70. The overall structure and processing technology are simple, which helps to reduce costs and improve production efficiency.

[0069] In this embodiment, the positive electrode tab 60 and the negative electrode tab 70 are respectively disposed on both sides of the core body.

[0070] Thus, this application is particularly applicable to cores where the positive tab 60 and the negative tab 70 are located on different sides, for example, this application is particularly applicable to cores of cylindrical batteries.

[0071] The specific processing steps for the core are as follows:

[0072] When starting the winding process, first insert both separators 100 into the winding needle simultaneously and wind the separators 100 several times; the specific number of turns is not limited. Then, insert the insertion end of the negative electrode 90 between the two separators 100 and begin winding; the specific number of turns is not limited. Finally, insert the insertion end of the positive electrode 80 under one of the separators 100 and begin winding until the winding is complete. When cutting, first cut the positive electrode 80, then cut the negative electrode 90, and finally cut the separator 100. Apply termination tape for fixation. At the end of the winding core, the ending positions of the positive electrode 80 and the negative electrode 90 are not limited.

[0073] The core structure is shown in Figures 8-10. After winding, the position of the tabs in the core is shown in Figures 8-10.

[0074] The positive electrode 80 and negative electrode 90 can achieve the conduction of the metal layers on both sides of the polymer layer of the composite current collector 10. Unlike the stacked structure, each electrode structure based on the composite current collector 10 does not need to be welded with two layers of tabs. This application greatly reduces the welding difficulty. As for the problem of high internal resistance in the welding of the wound cell, the internal resistance can be reduced by increasing the number of tabs, changing the material, shape, size of the tabs, or adjusting the position of the tabs.

[0075] Example 3

[0076] Referring to Figures 1-11, this application discloses a battery including the aforementioned winding core.

[0077] The battery in this application uses the aforementioned winding core, which has a simple overall structure and processing technology, thus reducing costs and improving production efficiency.

[0078] The specific manufacturing process of the battery is as follows:

[0079] Since each core has one positive tab 60 and two negative tabs 70, the first negative tab 701 and the second negative tab 702 are welded together to form the negative tab 70. The positive tab 60 is welded to the positive busbar, and the negative tab 70 is welded to the negative busbar. Finally, the busbar is welded to the cap and the steel shell, thus completing the welding of the battery cell.

Claims

1. An electrode structure based on a composite current collector, comprising: A composite current collector, wherein a first surface of the composite current collector is alternately provided with a first foil area and a first coating area along its length direction, and a second surface of the composite current collector is alternately provided with a second foil area and a second coating area along its length direction; The electrode has one end connected to one of the first foil regions and the other end connected to one of the second foil regions to conduct the composite current collector.

2. The electrode structure based on a composite current collector according to claim 1, wherein, The composite current collector includes a first metal layer, an intermediate polymer layer and a second metal layer stacked sequentially. The first metal layer is disposed on the first surface of the intermediate polymer layer and the second metal layer is disposed on the second surface of the intermediate polymer layer. The first surface and the second surface of the intermediate polymer layer are two surfaces with opposite positions to the intermediate polymer layer.

3. The electrode structure based on a composite current collector according to claim 1, wherein, The first surface and the second surface of the composite current collector are two surfaces whose installation positions are opposite to those of the composite current collector.

4. The electrode structure based on a composite current collector according to claim 1, wherein, One electrode tab is provided, and the electrode tab is a positive electrode tab, which forms a positive electrode plate after being connected to the composite current collector; Alternatively, the electrode tabs are provided in two forms, namely a first negative electrode tab and a second negative electrode tab, which are respectively connected to the composite current collector to form a negative electrode sheet.

5. The electrode structure based on a composite current collector according to claim 4, wherein, The first surface of the composite current collector is alternately provided with two first coating areas and three first foil areas along its length direction, and the second surface of the composite current collector is alternately provided with two second coating areas and three second foil areas along its length direction. One end of the positive electrode tab is welded to the first foil area located in the middle or near the middle position, and the other end of the positive electrode tab is welded to the second foil area located in the middle or near the middle position, so as to conduct the composite current collector.

6. The electrode structure based on a composite current collector according to claim 4, wherein, The first surface of the composite current collector is alternately provided with a first coating area and two first foil areas along its length direction, and the second surface of the composite current collector is alternately provided with a second coating area and two second foil areas along its length direction. One end of the first negative electrode tab is welded to the first foil area located at the first end position, and the other end of the first negative electrode tab is welded to the second foil area located at the first end position, so as to conduct the composite current collector; One end of the second negative electrode tab is welded to the first foil area located at the end position, and the other end of the second negative electrode tab is welded to the second foil area located at the end position to conduct the composite current collector.

7. The electrode structure based on a composite current collector according to claim 1, wherein, The overall shape of the electrode is "U" or "V".

8. A core, comprising a separator and an electrode structure based on a composite current collector as described in any one of claims 1-7, wherein the positive electrode, the separator, and the negative electrode are sequentially stacked and wound to form a core body; After winding, the first negative electrode tab and the second negative electrode tab are connected to form a negative electrode tab.

9. The winding core according to claim 8, wherein, The positive electrode tab and the negative electrode tab are respectively disposed on both sides of the core body.

10. A battery comprising a winding core as described in any one of claims 8-9.

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