Pole piece structure, battery cell structure and battery

Abstract

The utility model relates to the technical field of lithium ion battery, especially relates to a pole piece structure, roll core structure and battery. The pole piece structure in the utility model includes pole piece and tab. The pole piece includes current collector and the active material layer of being arranged in the current collector at least one side. The tab includes connecting portion and leading-out portion, and the connecting portion is laminated and is connected in one side of the current collector, and the leading-out portion is located outside the current collector. The width of connecting portion is greater than the width of leading-out portion, and the thickness of connecting portion is 2~5mu, and it is less than the thickness of leading-out portion, and the cross section area of connecting portion is 90%~100% of the cross section area of leading-out portion. The cross section area of connecting portion and leading-out portion is close, avoids the melting phenomenon of the overcurrent of tab due to the too thin connecting portion of tab. The thin connecting portion of laminating with the current collector improves the space utilization of the battery structure when preparing the battery structure, thereby increasing the energy density of the battery structure. The utility model further provides a battery structure and battery.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery technology, and in particular to an electrode structure, a cell structure, and a battery. Background Technology

[0002] Currently, the tabs used in lithium batteries on the market are mostly between 0.05-0.2mm thick and 3-6mm wide. Consumer batteries, however, prioritize rate performance, resulting in thinner positive and negative electrode layers, with each active material layer typically between 0.03-0.05mm thick. When tabs are soldered onto the electrode sheets, their thickness exceeds the thickness of the active material layers, making the tab the thickest part of the electrode. Applying adhesive tape further increases the thickness. For the cell structure, the thickness dimension is fixed; the thickness of the tabs occupies space within the cell structure, reducing overall space utilization and consequently lowering the cell's energy density.

[0003] Developing a structure that can improve both the space utilization of the battery cell and the energy density of the battery has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] The purpose of this invention is to provide an electrode structure and a cell structure for a battery, thereby improving the space utilization and energy density of the cell structure. To address the problems and shortcomings of existing technologies, this invention provides an electrode structure, a cell structure, and a battery. The electrode structure of this invention includes an electrode and tabs.

[0005] The electrode includes a current collector and an active material layer disposed on at least one side of the current collector;

[0006] The electrode tab includes a connecting part and a lead-out part; the connecting part is stacked and connected to one side of the current collector, and the lead-out part is located outside the current collector;

[0007] The width of the connecting part is greater than the width of the lead-out part, the thickness of the connecting part is less than the thickness of the lead-out part, the thickness of the connecting part is less than the thickness of the active material layer, and the cross-sectional area of ​​the connecting part is 90% to 100% of the cross-sectional area of ​​the lead-out part.

[0008] Optionally, a first groove penetrating the current collector is provided on the active material layer on the first side of the current collector; the connecting portion is disposed in the first groove;

[0009] The projection of the first groove is located within the projection of the active material layer on the second side of the current collector.

[0010] Optionally, a second groove is further provided on the active material layer on the first side of the current collector; the second groove is provided around the top edge of the first groove; the depth of the second groove is less than the depth of the first groove;

[0011] The electrode structure further includes electrode tab adhesive paper; the electrode tab adhesive paper is disposed in the second groove and covers the electrode tab;

[0012] The edge of the tab adhesive paper extends 0.5-2mm beyond the edge of the first groove.

[0013] Optionally, the electrode structure further includes protective adhesive paper; the protective adhesive paper is disposed on the active material layer on the first or second side of the current collector to cover the area of ​​the tab on the other polarity electrode.

[0014] Optionally, a third groove is further provided on the active material layer on the first or second side of the current collector; the protective adhesive paper is located in the third groove.

[0015] Optionally, the thickness of the tab adhesive paper is 8μm~16μm; and / or,

[0016] The thickness of the protective adhesive paper is 8μm~16μm.

[0017] Optionally, at least one of the tab adhesive paper and the protective adhesive paper includes a skeleton layer and an adhesive layer; the adhesive layer faces the active material layer;

[0018] The skeleton layer is a polyester film, and the adhesive layer is a latex adhesive layer, an acrylic adhesive layer, or a rubber adhesive layer.

[0019] Optionally, the depth of the second groove is greater than the thickness of the tab adhesive paper;

[0020] The thickness of the electrode tab is greater than the depth of the first groove;

[0021] The sum of the thickness A of the electrode tab and the thickness of the electrode tab adhesive paper is H1, and the thickness of the active material layer on the first side of the current collector is H2, -2μm≤H1-H2≤6μm;

[0022] The depth of the third groove is greater than the thickness of the protective adhesive paper.

[0023] This utility model also provides a battery cell structure, which includes a positive electrode structure and a negative electrode structure;

[0024] At least one of the positive electrode structure and the negative electrode structure adopts the electrode structure described in any of the above descriptions.

[0025] Optionally, the cell structure includes a positive electrode structure and a negative electrode structure;

[0026] The positive electrode structure adopts the above-mentioned electrode structure, and the tab adhesive paper and protective adhesive paper on the positive electrode structure are respectively positive tab adhesive paper and positive protective adhesive paper.

[0027] The negative electrode structure adopts the above-mentioned electrode structure, and the tab adhesive paper and protective adhesive paper on the negative electrode structure are respectively negative electrode tab adhesive paper and negative electrode protective adhesive paper.

[0028] The positive electrode adhesive paper is opposite to the negative electrode protective adhesive paper; the projection of the negative electrode protective adhesive paper in the thickness direction of the electrode sheet is located within the positive electrode adhesive paper; the ratio of the surface area of ​​the negative electrode protective adhesive paper to the surface area of ​​the positive electrode adhesive paper is 50% to 85%.

[0029] The negative electrode adhesive paper and the positive electrode protective paper are arranged opposite to each other; the projection of the positive electrode protective paper in the thickness direction of the electrode sheet is located inside the negative electrode adhesive paper; the ratio of the surface area of ​​the positive electrode protective paper to the surface area of ​​the negative electrode adhesive paper is 50% to 85%.

[0030] This utility model also provides a battery, which includes the cell structure described in any of the above claims.

[0031] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0032] (1) The connection between the tab and the current collector is relatively thin. When using the electrode structure with this type of tab to prepare the cell structure, the space utilization of the cell structure can be improved and the energy density of the cell structure can be increased.

[0033] (2) The cross-sectional areas of the connecting part and the lead-out part are close, so that the conductivity of the connecting part and the lead-out part is basically the same, avoiding the phenomenon of melting due to overcurrent caused by the connecting part of the electrode being too thin.

[0034] The above and other objects, advantages and features of this utility model will become more apparent to those skilled in the art from the following detailed description of specific embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0035] The following sections will describe some specific embodiments of the present invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0036] Figure 1 This is a schematic diagram of the electrode structure according to an embodiment of the present invention;

[0037] Figure 2This is a schematic diagram of the electrode structure according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the electrode structure according to an embodiment of the present invention;

[0039] Figure 4 This is a front view of an embodiment of the electrode structure of this utility model;

[0040] Figure 5 This is a schematic diagram of the battery cell structure according to an embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of a typical structure of an embodiment of the present invention.

[0042] In the figure: 1-Electrode structure; 10-Electrode, 101-Positive electrode, 102-Negative electrode, 11-Current collector, 12-Active material layer on the first side, 13-Active material layer on the second side, 14-First groove, 15-Second groove, 16-Third groove, 17-Electrode tab adhesive paper, 18-Protective adhesive paper; 20-Electrode tab, 21-Connecting part, 22-Lead-out part. Detailed Implementation

[0043] The following reference Figures 1 to 6 This invention describes an electrode structure, a cell structure, and a battery according to an embodiment of the present invention. In this description, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included.

[0044] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0045] Figure 1This is a schematic diagram of an electrode structure according to an embodiment of the present invention. Figure 1 As shown, combined with Figures 2 to 6 This invention provides an electrode structure 1, which includes an electrode 10 and a tab 20. The electrode 10 includes a current collector 11 and an active material layer disposed on at least one side of the current collector 11. The tab 20 includes a connecting portion 21 and a lead-out portion 22. The connecting portion 21 is stacked and connected to one side of the current collector 11, and the lead-out portion 22 is located outside the current collector 11. The width of the connecting portion 21 is greater than the width of the lead-out portion 22, the thickness of the connecting portion 21 is less than the thickness of the active material layer and less than the thickness of the lead-out portion 22, and the cross-sectional area of ​​the connecting portion 21 is 90% to 100% of the cross-sectional area of ​​the lead-out portion 22.

[0046] Specifically, the tabs 20 on the electrode 10 are configured as two parts with different widths and thicknesses. The connecting part 21, which is thinner and wider, is electrically connected to the current collector 11 on one side; the lead-out part 22, which is thicker and narrower, is located outside the current collector 11. The thickness of the connecting part 21 can be any value between 2 and 5 μm.

[0047] In this embodiment, the cross-sectional areas of the connecting portion 21 and the lead-out portion 22 are close, making their conductivity essentially the same. This avoids the electrode 20 from melting due to overcurrent caused by the connecting portion 21 being too thin. The thinner connecting portion 21, which is stacked with the current collector 11, improves the space utilization of the battery cell structure during fabrication, thereby increasing the energy density of the battery cell structure.

[0048] In some embodiments of this utility model, a first groove 14 penetrating the current collector 11 is provided on the active material layer 12 on the first side of the current collector 11, and a connecting portion 21 is disposed in the first groove 14. The projection of the first groove 14 is located within the projection of the active material layer 13 on the second side of the current collector 11.

[0049] In this embodiment, both sides of the current collector 11 are coated with an active material layer. A first groove 14 is formed on the active material layer of the first side, penetrating the first active material layer. That is, the current collector 11 is exposed within the first groove 14. A connecting portion 21 is disposed within the first groove 14, and the connecting portion 21 of the electrode tab 20 contacts the current collector 11. The projection of the first groove 14 lies within the projection of the active material layer 13 on the second side of the current collector 11.

[0050] In this embodiment, an active material layer is disposed on the second side of the current collector 11 opposite to the first groove 14, so that the cell structure is prepared using the electrode structure 1 in this embodiment, thereby further improving the energy density of the cell structure.

[0051] In some embodiments of this invention, a second groove 15 is further provided on the active material layer 12 on the first side of the current collector 11; the second groove 15 is disposed around the top edge of the first groove 14. The depth of the second groove 15 is less than the depth of the first groove 14. The electrode structure 1 also includes an electrode tab adhesive paper 17, which is disposed in the second groove 15 and covers the electrode tab 20. The edge of the electrode tab adhesive paper 17 extends beyond the edge of the first groove 14 by 0.5 mm to 2 mm.

[0052] In this embodiment, the first groove 14 and the second groove 15 are disposed on the same side of the current collector 11, and the sum of the depths of the first groove 14 and the second groove 15 is equal to the thickness of the active material layer. When the connecting portion 21 of the tab 20 is placed into the first groove 14, the tab adhesive tape 17 is embedded in the second groove 15 and covers the tab 20. The width of the tab adhesive tape 17 is greater than the width of the first groove 14. It should be noted that the width of the first groove 14 is the dimension along the width direction of the tab. The tab adhesive tape 17 is located in the second groove 15, avoiding the increase in the thickness of the electrode structure 1 caused by attaching the tab adhesive tape 17, thereby improving the energy density of the cell structure prepared using the electrode structure 1 in this embodiment. The length of the tab adhesive tape 17 is greater than the width of the first groove 14, which enables the tab adhesive tape 17 to completely cover the connecting portion 21, resulting in better insulation effect of the tab adhesive tape 17, and making it less likely for the tab 20 to short-circuit with the electrode 10 of opposite polarity.

[0053] In some embodiments of this utility model, the electrode structure 1 further includes a protective adhesive paper 18, which is disposed on the active material layer 13 on the first or second side of the current collector 11 to cover the tab 20 area on the other polar electrode 10.

[0054] In this embodiment, on the opposing surfaces of the two electrode structures 1 with opposite polarities, one is provided with a tab 20 and tab adhesive tape 17, and the other is provided with protective adhesive tape 18. This ensures that neither of the two opposing sides of the two electrodes 10 with opposite polarities has an active material layer exposed at the tab 20. This reduces the impact of excessively high or low N / P values ​​on the charging and discharging of the cell structure.

[0055] like Figure 3 As shown, in some embodiments of this utility model, a third groove 16 is further provided on the active material layer 13 on the first or second side of the current collector 11. The protective adhesive paper 18 is located in the third groove 16.

[0056] In this embodiment, the protective adhesive paper 18 is located in the third groove 16, which not only helps to fix the protective adhesive paper 18, but also reduces the thickness of the electrode structure 1 and improves the space utilization and energy density of the cell structure.

[0057] In some embodiments of this utility model, the thickness of the tab adhesive paper 17 is 8μm~16μm.

[0058] In some embodiments of this utility model, the thickness of the protective adhesive paper 18 is 8μm~16μm.

[0059] In some embodiments of this utility model, the thickness of the tab adhesive paper 17 is 8μm~16μm, and the thickness of the protective adhesive paper 18 is 8μm~16μm.

[0060] In the above embodiments, the thickness of the protective adhesive tape 18 and / or the tab adhesive tape 17 is 8μm to 16μm, specifically any value between 8μm and 16μm, such as 8μm, 9.5μm, 11μm, 13μm, 14.5μm, 16μm, etc. Setting the thickness of the protective adhesive tape 18 and / or the tab adhesive tape 17 within the above range is beneficial to improving the overall consistency of the cell structure and increasing the space utilization of the cell structure.

[0061] In some embodiments of this invention, the tab adhesive tape 17 includes a skeleton layer and an adhesive layer, with the adhesive layer facing the active material layer. In this embodiment, the tab adhesive tape 17 is composed of an adhesive layer and a skeleton layer. The skeleton layer provides support for the tab adhesive tape 17 and increases its strength, thereby preventing deformation and tearing. The adhesive layer facing the active material layer increases the adhesion between the tab adhesive tape 17 and the active material layer, reducing the risk of the tab adhesive tape 17 detaching.

[0062] In some other embodiments of this invention, the protective adhesive tape 18 includes a skeleton layer and an adhesive layer, with the adhesive layer facing the active material layer. In this embodiment, the protective adhesive tape 18 is composed of an adhesive layer and a skeleton layer. The skeleton layer provides support for the protective adhesive tape 18 and increases its strength, thereby preventing deformation and tearing. The adhesive layer facing the active material layer increases the adhesion between the protective adhesive tape 18 and the active material layer, reducing the risk of the protective adhesive tape 18 detaching.

[0063] In some other embodiments of this utility model, both the tab adhesive paper 17 and the protective adhesive paper 18 include a skeleton layer and an adhesive layer, with the adhesive layer facing the active material layer.

[0064] In a further embodiment of this invention, the skeleton layer is a polyester film, and the adhesive layer is a latex adhesive layer, an acrylic adhesive layer, or a rubber adhesive layer. In this embodiment, the adhesive layer can be selected from one of the latex adhesive layer, an acrylic adhesive layer, or a rubber adhesive layer, increasing the variety of options available.

[0065] In some embodiments of this utility model, the depth of the second groove 15 is greater than the thickness of the tab adhesive paper 17. The thickness of the tab 20 is greater than the depth of the first groove 14. The sum of the thickness A of the tab 20 and the thickness of the tab adhesive paper 17 is H1, and the thickness of the active material layer 12 on the first side of the current collector 11 is H2, where -2μm≤H1-H2≤6μm. H1-H2 can be any value between 2μm and 6μm, specifically, such as 2μm, 3μm, 5μm, etc. The depth of the third groove 16 is greater than the thickness of the protective adhesive paper 18.

[0066] The values ​​of H1 and H2 are roughly equivalent, improving the consistency of the cell structure. The thickness of the protective adhesive paper 18 is less than the depth of the third groove 16, used to balance the protruding portion of the adhesive paper 17 when the sum of the thickness of the tab 20 and the thickness of the tab adhesive paper 17 exceeds the depth of the first groove 14. This improves the space utilization of the cell structure and increases the energy density of the cell structure.

[0067] like Figure 6 As shown, this utility model also provides a battery cell structure, which includes a positive electrode structure and a negative electrode structure. The positive electrode structure is electrode structure 1 in any of the above embodiments. Using electrode structure 1 in any of the above embodiments as the positive electrode structure of the battery cell structure is beneficial to improving the space utilization rate and energy density of the battery cell structure.

[0068] like Figure 5 As shown, this utility model also provides a battery cell structure, which includes a positive electrode structure and a negative electrode structure. The negative electrode structure is electrode structure 1 in any of the above embodiments.

[0069] Using the electrode structure 1 in any of the above embodiments as the negative electrode structure of the cell structure is beneficial to improving the space utilization rate and energy density of the cell structure.

[0070] This utility model also provides a battery cell structure, which includes a positive electrode structure and a negative electrode structure. Both the positive electrode structure and the negative electrode structure are electrode structure 1 in any of the above embodiments.

[0071] Both the positive electrode structure and the negative electrode structure use the cell structure of electrode structure 1 in any of the above embodiments, which is beneficial to improve the space utilization rate of the cell structure and the energy density of the cell structure.

[0072] In some embodiments of the battery cell structure of this utility model, the battery cell structure includes a positive electrode structure and a negative electrode structure. The positive electrode structure adopts electrode structure 1 as described in any of the above embodiments, with the tab adhesive 17 and protective adhesive 18 on the positive electrode structure being the positive tab adhesive 17 and positive protective adhesive 18, respectively. The negative electrode structure adopts electrode structure 1 as described in any of the above embodiments, with the tab adhesive 17 and protective adhesive 18 on the negative electrode structure being the negative tab adhesive 17 and negative protective adhesive 18, respectively. The positive tab adhesive 17 is opposite to the negative protective adhesive 18; the projection of the negative protective adhesive 18 in the thickness direction of the electrode 10 is located within the positive tab adhesive 17. The ratio of the surface area of ​​the negative protective adhesive 18 to the surface area of ​​the positive tab adhesive 17 is 50% to 85%. The negative tab adhesive 17 and positive protective adhesive 18 are arranged opposite each other. The projection of the positive electrode protective film 18 onto the thickness direction of the electrode sheet 10 lies within the negative electrode tab film 17. The ratio of the surface area of ​​the positive electrode protective film 18 to the surface area of ​​the negative electrode tab film 17 is 50% to 85%.

[0073] In this embodiment, the portion of the positive electrode active material layer covered by the two oppositely polarized electrodes 10 is greater than the portion of the negative electrode active material layer covered, thus avoiding lithium plating during charging and discharging.

[0074] This invention also provides a battery comprising the cell structure described in any of the above embodiments. Batteries using the above cell structure exhibit improved space utilization and increased energy density.

[0075] Therefore, those skilled in the art should recognize that although many exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. An electrode structure, characterized in that, Including electrodes and tabs; The electrode includes a current collector and an active material layer disposed on at least one side of the current collector; The electrode tab includes a connecting part and a lead-out part; the connecting part is stacked and connected to one side of the current collector, and the lead-out part is located outside the current collector; The width of the connecting part is greater than the width of the lead-out part, the thickness of the connecting part is less than the thickness of the lead-out part, the thickness of the connecting part is less than the thickness of the active material layer, and the cross-sectional area of ​​the connecting part is 90% to 100% of the cross-sectional area of ​​the lead-out part.

2. The electrode structure according to claim 1, characterized in that, On the active material layer on the first side of the current collector, a first groove extending through the current collector is provided; the connecting portion is disposed within the first groove; The projection of the first groove is located within the projection of the active material layer on the second side of the current collector.

3. The electrode structure according to claim 2, characterized in that, A second groove is further provided on the active material layer on the first side of the current collector; the second groove is arranged around the top edge of the first groove; the depth of the second groove is less than the depth of the first groove; The electrode structure also includes electrode tab adhesive paper; the electrode tab adhesive paper is disposed in the second groove and covers the electrode tab; The edge of the tab adhesive paper extends 0.5-2mm beyond the edge of the first groove.

4. The electrode structure according to claim 3, characterized in that, The electrode structure also includes protective adhesive paper; the protective adhesive paper is disposed on the active material layer on the first or second side of the current collector to cover the area of ​​the tab on the other polarity electrode.

5. The electrode structure according to claim 4, characterized in that, A third groove is also provided on the active material layer on the first or second side of the current collector; the protective adhesive paper is located in the third groove.

6. The electrode structure according to claim 4 or 5, characterized in that, The thickness of the tab adhesive paper is 8μm~16μm; and / or, The thickness of the protective adhesive paper is 8μm~16μm.

7. The electrode structure according to claim 4 or 5, characterized in that, At least one of the tab adhesive paper and the protective adhesive paper includes a skeleton layer and an adhesive layer; the adhesive layer faces the active material layer; The skeleton layer is a polyester film, and the adhesive layer is a latex adhesive layer, an acrylic adhesive layer, or a rubber adhesive layer.

8. The electrode structure according to claim 5, characterized in that, The depth of the second groove is greater than the thickness of the tab adhesive paper; The thickness of the electrode tab is greater than the depth of the first groove; The sum of the thickness A of the electrode tab and the thickness of the electrode tab adhesive paper is H1, and the thickness of the active material layer on the first side of the current collector is H2, -2μm≤H1-H2≤6μm; The depth of the third groove is greater than the thickness of the protective adhesive paper.

9. A battery cell structure, characterized in that, Including positive electrode structure and negative electrode structure; At least one of the positive electrode structure and the negative electrode structure adopts the electrode structure according to any one of claims 1-8.

10. A battery cell structure, characterized in that, Including positive electrode structure and negative electrode structure; The positive electrode structure adopts the electrode structure described in claim 6 or 7, and the tab adhesive paper and protective adhesive paper on the positive electrode structure are respectively positive tab adhesive paper and positive protective adhesive paper. The negative electrode structure adopts the electrode structure described in claim 6 or 7, and the tab adhesive paper and protective adhesive paper on the negative electrode structure are respectively negative electrode tab adhesive paper and negative electrode protective adhesive paper. The positive electrode adhesive paper is opposite to the negative electrode protective adhesive paper; the projection of the negative electrode protective adhesive paper in the thickness direction of the electrode sheet is located within the positive electrode adhesive paper; the ratio of the surface area of ​​the negative electrode protective adhesive paper to the surface area of ​​the positive electrode adhesive paper is 50% to 85%. The negative electrode adhesive paper and the positive electrode protective paper are arranged opposite to each other; the projection of the positive electrode protective paper in the thickness direction of the electrode sheet is located inside the negative electrode adhesive paper; the ratio of the surface area of ​​the positive electrode protective paper to the surface area of ​​the negative electrode adhesive paper is 50% to 85%.

11. A battery, characterized in that, Includes the cell structure described in claim 9 or 10.

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