Pole piece structure, battery cell and battery
By coating a liquid-retaining layer onto the active material layer of the electrode and forming a porous structure, the problem of reduced liquid-retaining performance of the cell caused by increased electrode compaction density is solved, thereby improving the charging and discharging efficiency and safety of the battery and reducing the risk of failure in the later stages of cycling.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG LIWINON ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-06-05
AI Technical Summary
Increased electrode compaction density leads to reduced cell liquid retention performance, affecting battery charge/discharge efficiency and safety, and increasing the risk of failure in the later stages of cycling.
A liquid-retaining layer is coated on the active material layer. The liquid-retaining layer has liquid storage pores to form a porous structure, which ensures effective wetting of the electrolyte and increases the liquid retention performance of the electrode.
It improves the liquid retention performance of the electrode, avoids local overheating, enhances the charging and discharging efficiency and safety of the battery, and extends the cycle life of the cell.
Smart Images
Figure CN224328684U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to an electrode structure, a battery cell, and a battery. Background Technology
[0002] In recent years, consumer lithium battery technology has continued to iterate. With the surge in demand for smartphones, laptops, wearable devices, and emerging consumer electronics, lithium batteries are developing towards higher energy density and thinner designs.
[0003] As users demand increasingly higher energy density from lithium batteries, the compaction density of the anode and cathode is continuously increasing. However, this higher compaction density leads to reduced porosity, affecting the effective wetting of the electrolyte and decreasing the cell's electrolyte retention capacity. If the electrolyte cannot fully penetrate the electrode material, it may cause localized overheating, impacting the battery's charge / discharge efficiency and safety, and consequently affecting the cell's cycle performance, increasing the risk of cell failure in the later stages of cycling. Utility Model Content
[0004] The technical problem to be solved by this invention is: how to solve the problem of reduced electrolyte retention performance of the battery cell when the electrode density increases.
[0005] To solve the above-mentioned technical problems, this utility model provides an electrode structure, comprising:
[0006] current collector;
[0007] An active material layer, said active material layer being coated on the surface of the current collector; and,
[0008] A liquid-retaining layer is coated on the side of the active material layer away from the current collector, and the liquid-retaining layer has liquid storage pores to form a porous structure.
[0009] More preferably, the relationship between the thickness L1 of the active material layer and the thickness L2 of the liquid-retaining layer satisfies: L1≥L2.
[0010] More preferably, the thickness L2 of the liquid-retaining layer satisfies: 1μm≤L2≤3μm.
[0011] More preferably, the thickness L2 of the liquid-retaining layer satisfies: L2 = 2 μm.
[0012] More preferably, the liquid-retaining layer is a PVDF coating.
[0013] More preferably, the porosity of the liquid-retaining layer is 20%-50%.
[0014] More preferably, the liquid storage hole is a through hole or a blind hole.
[0015] More preferably, the active material layer is a carbon base layer or a silicon base layer.
[0016] This utility model also discloses a battery cell, including an anode plate, a cathode plate, and a diaphragm disposed between the anode plate and the cathode plate, wherein the anode plate, the cathode plate, and the diaphragm are wound together to form the battery cell;
[0017] The anode sheet is the electrode structure described above.
[0018] This utility model also discloses a battery, including a casing and the aforementioned battery cell, wherein the casing covers the battery cell.
[0019] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0020] This invention coats an active material layer with a liquid-retaining layer, which has several liquid storage pores to form a porous structure. This ensures that the electrode effectively absorbs the electrolyte and is effectively wetted, thereby increasing the electrolyte retention performance of the electrode, avoiding local overheating, improving the charging and discharging efficiency and safety of the battery, and also improving the long-cycle performance of the cell and reducing the risk of cell failure in the later stages of the cycle. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the electrode structure described in this utility model.
[0022] Figure 2 This is a partial schematic diagram of the liquid-retaining layer described in this utility model.
[0023] Figure label:
[0024] 10. Current collector; 20. Active material layer; 30. Liquid retention layer; 31. Liquid storage hole. Detailed Implementation
[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0026] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0027] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings are used only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0028] 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0029] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0030] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0031] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0032] like Figures 1-2 As shown, this utility model proposes an electrode structure, including a current collector 10, an active material layer 20, and a liquid retention layer 30; wherein, the active material layer 20 is coated on the surface of the current collector 10; the liquid retention layer 30 is coated on the side of the active material layer 20 away from the current collector 10, and the liquid retention layer 30 has liquid storage holes 31 to form a porous structure.
[0033] In this embodiment, the liquid-retaining layer 30 has a plurality of liquid storage holes 31 to form a porous structure, which can ensure that the electrode effectively absorbs the electrolyte and is effectively wetted, thereby increasing the liquid-retaining performance of the electrode, avoiding local overheating, improving the charging and discharging efficiency and safety of the battery, and also improving the long-cycle performance of the cell and reducing the risk of cell failure in the later stages of the cycle.
[0034] In some embodiments, the relationship between the thickness L1 of the active material layer 20 and the thickness L2 of the liquid retention layer 30 satisfies: L1≥L2, so as to improve the wetting and liquid retention capabilities.
[0035] In some embodiments, the thickness L2 of the liquid retention layer 30 satisfies: 1μm≤L2≤3μm; as a preferred embodiment, the thickness L2 of the liquid retention layer 30 satisfies: L2=2μm, which effectively avoids difficulties in electrolyte wetting.
[0036] In some embodiments, the liquid-retaining layer 30 is a PVDF (polyvinylidene fluoride) coating. The porous structure of the PVDF coating enables it to effectively retain liquid, ensuring the porosity of the electrode and thus maintaining the low resistivity and overall performance of the battery.
[0037] In addition, the PVDF coating exhibits excellent electrode adhesion and dimensional stability under wet conditions, which further enhances its liquid retention capacity.
[0038] In other embodiments, the liquid-retaining layer 30 may be formed by multiple coatings of PVDF coating to ensure the uniformity of the coating and balance porosity and conductivity.
[0039] In some embodiments, the porosity of the liquid-retaining layer 30 is 20%-50%. When the porosity is below 20%, it restricts electrolyte wetting and lithium-ion diffusion, leading to a decrease in kinetic performance. When the porosity is above 50%, it reduces the mechanical strength of the electrode and decreases the active material loading. The porosity of the liquid-retaining layer 30, at 20%-50%, ensures effective electrolyte wetting, improves the liquid-retaining performance of the electrode, and simultaneously guarantees both kinetic performance and mechanical strength.
[0040] In some embodiments, the liquid storage hole 31 is a through hole or a blind hole. The shape and arrangement of the liquid storage hole 31 can be designed according to requirements.
[0041] In some embodiments, the active material layer 20 is a carbon base layer, preferably a graphite layer. Graphite has excellent electrical and thermal conductivity, which enables it to efficiently conduct current and heat in electronic devices, thereby improving device performance and stability. Furthermore, graphite maintains stable physical and chemical properties at high temperatures, exhibiting excellent high-temperature resistance and corrosion resistance, allowing for stable operation for extended periods in harsh environments. Graphite materials also possess high specific energy, meaning higher battery energy per unit mass, and good chemical stability, maintaining good performance through multiple charge-discharge cycles and extending battery life.
[0042] In summary, the electrode structure proposed in this utility model, by coating the active material layer 20 with a liquid-retaining layer 30, and the liquid-retaining layer 30 having a plurality of liquid storage pores 31 to form a porous structure, can ensure that the electrode effectively absorbs electrolyte and is effectively wetted, thereby increasing the liquid-retaining performance of the electrode, avoiding local overheating, improving the charge and discharge efficiency and safety of the battery, and also improving the long-cycle performance of the cell and reducing the risk of cell failure in the later stages of cycling.
[0043] This utility model also proposes a battery cell, which includes an electrode assembly and an electrolyte. The electrode assembly includes an anode plate, a cathode plate, and a separator disposed between the anode plate and the cathode plate. The anode plate, cathode plate, and separator are wound to form the battery cell. The anode plate is the electrode structure described above. The specific structure of this electrode structure is as described in the above embodiments. Since this battery cell adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.
[0044] It should be noted that the battery cell mainly relies on the movement of metal ions between the anode and cathode plates to operate. The anode plate includes an anode current collector 10 and an anode active material layer 20. The anode current collector 10 has a coated area and an anode tab connected to the coated area. The anode active material layer 20 is coated on the surface of the anode current collector 10, and the liquid retention layer 30 is coated on the side of the anode active material layer 20 away from the anode current collector 10.
[0045] In some embodiments, the cathode active material of the battery cell in this example is lithium cobalt oxide, with a compaction density of 4.2 g / cm³. 3 The anode employs a double-layer coating method, meaning the current collector is coated with an anode active material, which is made of graphite with a compacted density of 1.78 g / cm³. 3 The surface is coated with a PVDF liquid-retaining layer with a thickness of 2 μm. The cathode structure of the comparative example is the same as that of this application, except that the anode electrode of the comparative example adopts a single-layer coating method, that is, the anode active material is coated on the current collector. The anode active material is made of graphite material with a compaction density of 1.78 g / cm³. 3The finished battery cells were sent for cycle testing; the results are shown in Table 1 below:
[0046] Table 1. Comparison of Cyclic Test Data of Finished Cells from Examples and Comparative Examples
[0047]
[0048] As shown in Table 1 above, the anode of this embodiment adopts a double-layer coating method. That is, when a liquid-retaining layer is coated on the surface, the liquid-retaining capacity of the cell is significantly increased, and the cycle performance of the cell is significantly improved.
[0049] This utility model also proposes a battery, including a casing and the aforementioned battery cell, with the casing covering the battery cell. The specific structure of the battery cell is as described in the above embodiments. Since this battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.
[0050] A battery is a device that converts chemical energy into electrical energy. It contains an electrolyte solution and metal electrodes, and is housed in a cup, tank, or other container (such as a shell) or a portion of a composite container to generate an electric current. Batteries typically have an anode and a cathode. With technological advancements, the term "battery" now generally refers to any small device capable of generating electrical energy, such as a solar cell. The main performance parameters of a battery include electromotive force, capacity, specific energy, and resistance. The principle of a battery: In a chemical battery, chemical energy is directly converted into electrical energy through spontaneous oxidation and reduction reactions within the battery. These reactions occur at the two electrodes.
[0051] Taking lithium batteries as an example, the cathode current collector can be made of aluminum, and the cathode active material layer can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The anode current collector can be made of copper, and the anode active material layer can be made of carbon-based materials (such as graphite), silicon-based materials, or alloy materials, etc. The separator can be made of PP (polypropylene) or PE (polyethylene), etc. The electrolyte is a material with good ionic conductivity, such as aqueous solutions of acids, alkalis, and salts, organic or inorganic non-aqueous solutions, molten salts, or solid electrolytes, etc.
[0052] In other embodiments, the battery can be a rechargeable battery, also known as a rechargeable battery or accumulator, which is a battery that can be recharged after being discharged to reactivate the active materials and continue to be used. Utilizing the reversibility of chemical reactions, a new battery can be constructed; that is, after a chemical reaction converts into electrical energy, the electrical energy can be used to repair the chemical system, and then the chemical reaction can be converted back into electrical energy. Therefore, it is called a rechargeable battery.
[0053] This utility model also proposes an electrical device, which includes the battery described above. The specific structure of the battery is as described in the above embodiments. Since this electrical device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.
[0054] The electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This embodiment does not impose special limitations on the above-mentioned electrical equipment.
[0055] The above description is merely a preferred embodiment of this utility model. It should be noted that, for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this utility model, and these improvements and substitutions should also be considered within the protection scope of this utility model. The basic principles, main features, and advantages of this utility model have been shown and described above. For those skilled in the art, it is obvious that this utility model is not limited to the details of the above preferred embodiments. The embodiments should be considered exemplary and non-limiting. The scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included within this utility model.
[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. An electrode structure, characterized in that, include: current collector; An active material layer is coated on the surface of the current collector; as well as, A liquid-retaining layer is coated on the side of the active material layer away from the current collector, and the liquid-retaining layer has liquid storage pores to form a porous structure.
2. The electrode structure according to claim 1, characterized in that, The relationship between the thickness L1 of the active material layer and the thickness L2 of the liquid-retaining layer satisfies: L1≥L2.
3. The electrode structure according to claim 1, characterized in that, The thickness L2 of the liquid retention layer satisfies: 1μm≤L2≤3μm.
4. The electrode structure according to claim 3, characterized in that, The thickness L2 of the liquid-retaining layer satisfies: L2=2μm.
5. The electrode structure according to claim 1, characterized in that, The liquid-retaining layer is a PVDF coating.
6. The electrode structure according to claim 1, characterized in that, The porosity of the liquid-retaining layer is 20%-50%.
7. The electrode structure according to claim 1, characterized in that, The liquid storage hole can be a through hole or a blind hole.
8. The electrode structure according to claim 1, characterized in that, The active material layer is a carbon base layer or a silicon base layer.
9. A battery cell, characterized in that, The battery cell includes an anode plate, a cathode plate, and a diaphragm disposed between the anode plate and the cathode plate, wherein the anode plate, the cathode plate, and the diaphragm are wound together to form the battery cell. Wherein, the anode sheet is the electrode structure described in any one of claims 1 to 8.
10. A battery, characterized in that, It includes a housing and the battery cell as described in claim 9, wherein the housing covers the battery cell.