Positive electrode sheet, battery cell, battery, and electric device
By setting an adhesive layer with connecting holes in the bending area of the electrode, the problem of active material shedding from the electrode is solved, thereby improving the battery's capacity and performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HEFEI GUOXUAN HIGH TECH POWER ENERGY
- Filing Date
- 2025-06-25
- Publication Date
- 2026-06-30
AI Technical Summary
In the bending area of the electrode in a lithium-ion battery, the active material is prone to detachment due to stress concentration, leading to battery capacity decay and performance reduction.
An adhesive layer is provided in the curved area of the electrode, and multiple through holes extending through its thickness are opened in the adhesive layer to expose the active material and increase the effective area for lithium ion insertion and extraction.
It significantly improves battery capacity and charge/discharge performance, enhances the structural strength and stability of the electrodes, and reduces the risk of active material shedding.
Smart Images
Figure CN224437579U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage technology, and in particular to a positive electrode sheet, a battery cell, a battery, and an electrical device. Background Technology
[0002] With the rapid development of new energy vehicles, lithium-ion batteries, as their core power source, are facing increasingly higher demands for performance such as high energy density and fast charging. To improve battery range, battery manufacturers generally adopt design schemes that increase the compaction density and areal density of electrode sheets to achieve higher energy density.
[0003] During the cell winding process, the active material on the electrode is prone to detachment (i.e., "R-corner shedding") due to stress concentration in the bending area (usually called the R-angle, which is the radius of curvature of the electrode at the corner). In related technologies, an adhesive layer is usually set in the bending area of the electrode to reduce the risk of material shedding.
[0004] However, the above methods will cause the battery capacity to decay, thereby reducing the battery performance. Utility Model Content
[0005] In view of the above problems, embodiments of this application provide a positive electrode sheet, a battery cell, a battery, and an electrical device that can reduce the impact of the adhesive layer on the battery cell capacity.
[0006] To achieve the above objectives, the embodiments of this application provide the following technical solutions:
[0007] In a first aspect, embodiments of this application provide a positive electrode sheet, comprising:
[0008] An electrode body, wherein the electrode body includes a region to be bent;
[0009] An adhesive layer is bonded to the region to be bent and covers at least a portion of the region to be bent, the adhesive layer having a plurality of through holes extending through its thickness.
[0010] In one possible implementation, the adhesive layer covers the entire area to be bent.
[0011] In one possible implementation, along the thickness direction of the positive electrode sheet, the electrode body has a first surface and a second surface disposed opposite to each other;
[0012] An adhesive layer is provided on both the first surface and the second surface at positions opposite to the area to be bent.
[0013] In one possible implementation, the total area of the plurality of connecting holes accounts for 30% to 80% of the total area of the adhesive layer.
[0014] In one possible implementation, the plurality of connecting holes are arranged in multiple rows and columns on the adhesive layer.
[0015] In one possible implementation, the shape of the connecting hole is at least one of a circle, an ellipse, and a polygon.
[0016] In one possible implementation, the thickness of the adhesive layer is 5 μm to 50 μm.
[0017] In a second aspect, embodiments of this application provide a battery cell, including a negative electrode sheet, a separator, and a positive electrode sheet as described in the first aspect, wherein the negative electrode sheet, the separator, and the positive electrode sheet are sequentially stacked and wound to form a wound structure;
[0018] The bending area of the positive electrode sheet constitutes the corner area of the wound structure.
[0019] Thirdly, embodiments of this application provide a battery including the cell described in the second aspect.
[0020] Fourthly, embodiments of this application provide an electrical device, including an electrical device and the battery described in the third aspect, wherein the battery is electrically connected to the electrical device and is used to provide electrical energy to the electrical device.
[0021] In the positive electrode sheet, battery cell, battery, and electrical device provided in this application embodiment, an adhesive layer is provided in at least a portion of the bending area of the positive electrode sheet, and the adhesive layer has multiple through-holes penetrating its thickness. In this way, the through-holes expose a portion of the bending area of the electrode sheet body, allowing some of the active material in the bending area to be exposed. Compared with the dense structure of the adhesive layer in related technologies, the through-holes significantly increase the effective area for lithium-ion insertion and extraction, enabling the battery cell to more fully utilize the positive electrode active material during charging and discharging, effectively improving battery capacity and thus enhancing battery performance.
[0022] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the positive electrode sheet, cell, battery, and electrical equipment provided by the embodiments of this application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific implementation methods. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 This is a schematic diagram of the structure of the positive electrode sheet provided in the embodiments of this application;
[0025] Figure 2 A side view of the positive electrode sheet provided in an embodiment of this application;
[0026] Figure 3 This is a schematic diagram of the battery cell structure provided in an embodiment of this application.
[0027] Explanation of reference numerals in the attached figures:
[0028] 100: Positive electrode sheet;
[0029] 110: Electrode body; 111: Area to be bent;
[0030] 120: Adhesive layer; 121: Connecting hole;
[0031] 200: Negative electrode plate;
[0032] 300: Separating membrane. Detailed Implementation
[0033] As described in the background section, to address the issue of active material detachment in the curved areas of the positive electrode, related technologies typically involve adhering a bonding layer of a certain thickness to the curved areas to prevent the active material from detaching. However, the bonding layer occupies part of the active area of the positive electrode, directly reducing the effective area for lithium-ion insertion and extraction. This, in turn, reduces battery capacity decay and lowers battery performance.
[0034] To address the aforementioned technical problems, embodiments of this application provide a positive electrode sheet, a battery cell, a battery, and an electrical device. By providing an adhesive layer in at least a portion of the bending area of the positive electrode sheet, and the adhesive layer having multiple through-holes penetrating its thickness, the through-holes expose a portion of the bending area of the electrode sheet body, thereby exposing some of the active material in the bending area. Compared to the dense structure of adhesive layers in related technologies, the through-holes significantly increase the effective area for lithium-ion insertion and extraction, allowing the battery cell to more fully utilize the positive electrode active material during charging and discharging, effectively improving battery capacity and thus enhancing battery performance.
[0035] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0036] This application provides a positive electrode 100, which is used in a battery cell. The positive electrode 100 includes an electrode body 110, and the electrode body 110 includes a bending region 111. It should be noted that the bending region 111 refers to a portion of the electrode body 110 involved in bending operations such as winding and stacking during the battery cell manufacturing process.
[0037] In this embodiment, the electrode body 110 includes a positive current collector and a positive active layer. The positive active layer is disposed on at least one side of the positive current collector in the thickness direction of the positive current collector. That is, the positive active layer is disposed on the upper surface and / or lower surface of the positive current collector.
[0038] The positive electrode active layer can be made of conventional materials, such as lithium-containing active materials, including at least one of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, ternary materials, lithium iron phosphate, lithium manganese iron phosphate, lithium vanadium phosphate, lithium vanadium oxide phosphate, and lithium-rich manganese-based materials. Ternary materials may include lithium nickel cobalt manganese oxide and / or lithium nickel cobalt aluminum oxide, etc.
[0039] The positive electrode 100 also includes an adhesive layer 120, which is bonded to the bending region 111 and covers at least a portion of the bending region 111. The adhesive layer 120, by covering at least a portion of the bending region 111, can firmly fix the active material to the electrode body 110 using its adhesive force, effectively preventing the active material from falling off and eliminating the risk of material loss at the source, thus ensuring the integrity and stability of the cell structure. The adhesive layer 120 is made of materials including, but not limited to, rubber or polyvinylidene fluoride.
[0040] Please continue to refer to this. Figure 1 The adhesive layer 120 has a plurality of connecting holes 121, which penetrate the adhesive layer 120 along its thickness direction. The shape of the connecting holes 121 is at least one of circular, elliptical, and polygonal. The polygonal shape can be quadrilateral, pentagonal, or other shapes.
[0041] In this way, the connecting hole 121 exposes a portion of the bending region 111 of the electrode body 110, allowing some of the active material in the bending region to be exposed. The connecting hole 121 can significantly increase the effective area for lithium-ion insertion and extraction, enabling the cell to make fuller use of the positive electrode active material during charging and discharging, effectively improving the battery capacity and thus enhancing battery performance.
[0042] In addition, the connecting hole 121 provides abundant channels for electrolyte penetration, enabling the electrolyte to penetrate the electrode body 110 in the bending area more quickly and evenly. This helps to improve the transmission efficiency of lithium ions between the electrolyte and the positive electrode 100, reduce the internal resistance of the battery, and improve the charging and discharging performance of the battery.
[0043] It should be noted that the adhesive layer 120 covers at least a portion of the bending area 111. This can be understood as the adhesive layer 120 covering part of the bending area 111, or it can be understood as the adhesive layer 120 covering the entire bending area. The fully covered adhesive layer 120 can evenly disperse these stresses, tightly fix the active material to the electrode body 110, effectively prevent the active material from falling off due to stress concentration, and greatly enhance the structural strength and stability of the bending area of the positive electrode 100.
[0044] Please refer to the attached document. Figure 2 In some embodiments, along the thickness direction of the positive electrode 100, the electrode body 110 has a first surface and a second surface disposed opposite to each other. An adhesive layer 120 is disposed on both the first and second surfaces at positions opposite to the bending region 111. Thus, the adhesive layer 120 covers both the positive and negative surfaces of the positive electrode 100, greatly reducing the risk of the active material detaching due to stress concentration.
[0045] It is important to understand that the orthographic projection of the adhesive layer 120 on the first surface onto the second surface can partially or completely overlap with the adhesive layer 120 on the second surface. This overlapping structure can create a mutual pulling mechanical effect within the positive electrode sheet 100, reducing the ability of the positive electrode sheet 100 to resist deformation during the winding process. Furthermore, the overlapping adhesive layers 120 can disperse these stresses, preventing stress concentration in a particular area, thereby enhancing the overall structural strength of the positive electrode sheet and reducing the risk of breakage or deformation.
[0046] In some embodiments, the total area of the plurality of connecting holes 121 accounts for 30% to 80% of the total area of the adhesive layer 120. Exemplarily, the total area of the plurality of connecting holes 121 accounts for 30%, 40%, 50%, 60%, 70%, 80% of the total area of the adhesive layer 120, as well as any interval value enclosed by two adjacent values.
[0047] This embodiment limits the total area of the multiple connecting holes 121 and the total area of the adhesive layer 120, preventing the total area of the multiple connecting holes 121 from being too small. This allows the multiple connecting holes 121 to expose a suitable active material layer of the electrode body, enabling the battery cell to make fuller use of the positive electrode active material during charging and discharging, effectively increasing the battery capacity and thus improving battery performance. It also prevents the total area of the multiple connecting holes 121 from being too large, thereby avoiding an excessive reduction in the mechanical fixing ability of the adhesive layer 120 and effectively reducing the risk of the active material layer falling off.
[0048] It should be noted that the multiple connecting holes 121 can be arranged regularly or irregularly on the adhesive layer 120. For example, the multiple connecting holes 121 are arranged in multiple rows and columns on the adhesive layer 120. (See attached diagram) Figure 1 Taking the indicated orientation as an example, multiple connecting holes 121 are arranged in a six-row, two-column pattern.
[0049] This embodiment, through a regular multi-row, multi-column arrangement, provides more and more uniform channels for the transport of lithium ions between the electrolyte and the positive electrode active material. This allows lithium ions to move more quickly and smoothly within the positive electrode 100, thereby improving the battery's charge / discharge rate and rate performance. Furthermore, the multi-row, multi-column arrangement makes the stress distribution among the multiple connecting holes 121 more uniform, reducing local stress concentration, lowering the risk of breakage or deformation of the positive electrode 100, enhancing the overall structural stability of the positive electrode 100, and extending the battery's lifespan.
[0050] In some embodiments, the thickness of the adhesive layer 120 is 5 μm to 50 μm. A suitable adhesive layer thickness ensures sufficient contact area and adhesion between the adhesive layer 120 and the active material, firmly fixing the active material to the electrode body 110. Furthermore, it avoids excessively thick adhesive layers 120, preventing an excessive increase in the overall thickness and mass of the positive electrode 100, thereby improving the energy density of the battery.
[0051] Please refer to the attached document. Figure 3 This application also provides a battery cell, including a negative electrode 200, a separator 300 and a positive electrode 100 as described in any of the above embodiments. The negative electrode 200, the separator 300 and the positive electrode 100 are stacked and wound in sequence to form a wound structure.
[0052] In this design, the bending region 111 of the positive electrode 100 forms a corner region of a wound structure. Given the presence of the adhesive layer 120 in the bending region 111, the adhesive layer 120 can mechanically fix the active material layer in the bending region, preventing the active material layer in the bending region 111 from falling off during the bending process, thus greatly reducing the risk of material loss.
[0053] In addition, the connection holes 121 of the adhesive layer 120 can also avoid excessive reduction of the active area of the positive electrode and improve the battery capacity.
[0054] It should be noted that, in this embodiment, the separator is located between any adjacent positive electrode 100 and negative electrode 200 to prevent short circuits between the positive electrode 100 and the negative electrode 200.
[0055] The separator 300 may include at least one of polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET). For example, it may be a single-layer PP film, a single-layer PE film, a single-layer PET film, a double-layer PP / PE film, or a three-layer PP / PE / PP composite film, etc.
[0056] This application also provides a battery, wherein the battery includes a battery casing (not shown in the figure) and a battery cell as described in any of the above embodiments, the battery cell being disposed within the battery casing. Since the battery includes the battery cell described in any of the above embodiments, the battery possesses all the structure and beneficial effects of the battery cell, and will not be described in detail here.
[0057] The battery casing can be cylindrical or square in shape. The material of the battery casing includes, but is not limited to, aluminum.
[0058] This application also provides an electrical device, including an electrical appliance and a battery as described in any of the above embodiments. The battery is electrically connected to the electrical appliance to provide electrical energy to it. Since the vehicle includes the battery described in any of the above embodiments, it possesses the structure and beneficial effects of a battery, and will not be described further in detail here.
[0059] The electrical equipment in this application embodiment can be a vehicle, for example, a new energy vehicle, which can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. Accordingly, the electrical device can be the vehicle's drive mechanism or the vehicle's control system.
[0060] In addition, electrical equipment can also serve as other energy storage devices, such as mobile phones, portable devices, laptops, electric toys, power tools, ships, and spacecraft. Among these, spacecraft can include airplanes, rockets, space shuttles, or spacecraft.
[0061] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.
[0062] In the description of the embodiments of this application, the terms "first," "second," "third," "fourth," etc. (if present) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.
[0063] In the description of the embodiments of this application, the term "and / or" merely indicates a relationship describing the associated objects, meaning that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the term "at least one" indicates any combination of at least two of a plurality of options, for example, including at least one of A, B, and C, which can represent any one or more elements selected from a set including communication between A, B, and C.
[0064] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.
[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A positive electrode plate, characterized in that, include: An electrode body, wherein the electrode body includes a region to be bent; An adhesive layer is bonded to the region to be bent and covers at least a portion of the region to be bent, the adhesive layer having a plurality of through holes extending through its thickness.
2. The positive electrode sheet according to claim 1, characterized in that, The adhesive layer covers the entire area to be bent.
3. The positive electrode sheet according to claim 1, characterized in that, Along the thickness direction of the positive electrode sheet, the electrode body has a first surface and a second surface disposed opposite to each other; An adhesive layer is provided on both the first surface and the second surface at positions opposite to the area to be bent.
4. The positive electrode sheet according to any one of claims 1-3, characterized in that, The total area of the plurality of interconnecting holes accounts for 30% to 80% of the total area of the adhesive layer.
5. The positive electrode sheet according to any one of claims 1-3, characterized in that, The multiple connecting holes are arranged in multiple rows and columns on the adhesive layer.
6. The positive electrode sheet according to claim 5, characterized in that, The shape of the connecting hole is at least one of the following: circular, elliptical, and polygonal.
7. The positive electrode sheet according to any one of claims 1-3, characterized in that, The thickness of the adhesive layer is 5μm to 50μm.
8. A battery cell, characterized in that, The invention includes a negative electrode sheet, a separator, and a positive electrode sheet as described in any one of claims 1-7, wherein the negative electrode sheet, the separator, and the positive electrode sheet are sequentially stacked and wound to form a wound structure; The bending area of the positive electrode sheet constitutes the corner area of the wound structure.
9. A battery, characterized in that, Includes the battery cell as described in claim 8.
10. An electrical appliance, characterized in that, It includes an electrical device and the battery as described in claim 9, wherein the battery is electrically connected to the electrical device and is used to provide electrical energy to the electrical device.