Electrode piece, electrode assembly and core package

Abstract

The utility model provides a pole piece, an electrode assembly and a core package, the pole piece comprises a current collector, and active material layers are arranged on two sides of the current collector; and the protective layer is arranged on one side, far away from the current collector, of the at least one active material layer, and one side, far away from the active material layer, of the protective layer is used for being connected with the base film. According to the technical scheme, the technical problem that the production yield of diaphragms is low can be solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of pole piece, specifically relates to a pole piece, electrode assembly and core package. BACKGROUND

[0002] The existing lithium battery core package is usually composed of a positive pole piece, a negative pole piece and a diaphragm, the diaphragm usually comprises a base film, a glue layer and a coating layer, the production process is complex, and due to the fact that the base film is relatively thin, the consistency problem is prone to occur in the process of coating ceramic and coating glue, so that the production yield of the diaphragm is relatively low. SUMMARY

[0003] The embodiment of the utility model provides a kind of pole piece, electrode assembly and core package, can improve the production yield of diaphragm is relatively low technical problem.

[0004] In the first aspect, the embodiment of the utility model provides a kind of pole piece, pole piece includes: current collector, the two sides of current collector are provided with active material layer;Protective layer, is located at least one active material layer side away from current collector, the side of protective layer away from active material layer is used to be connected with base film.

[0005] In an embodiment, the protective layer includes a ceramic layer.

[0006] In an embodiment, the thickness of the protective layer is between 0.5 μm and 3 μm.

[0007] In an embodiment, the pole piece includes a positive electrode unit or a negative electrode unit.

[0008] In an embodiment, the current collector of the positive electrode unit includes aluminum.

[0009] In an embodiment, the current collector of the negative electrode unit includes copper.

[0010] In an embodiment, the protective layer is provided on the active material layer on both sides of the current collector.

[0011] In the second aspect, the embodiment of the utility model provides an electrode assembly, and the electrode assembly includes: the above-mentioned pole piece;Base film, for being connected with pole piece.

[0012] In an embodiment, the electrode assembly further includes a connecting layer, the connecting layer is arranged on at least one side of the base film, and the base film is connected with the pole piece through the connecting layer.

[0013] In the third aspect, the embodiment of the utility model provides a core package, and the core package includes the above-mentioned electrode assembly.

[0014] The technical scheme of the utility model discloses, the active substance layer is arranged in two layers of current collector, and the protective layer is arranged on at least one active substance layer, and the protective layer is connected with the base film, so that the protective layer does not need to be coated on the surface of the base film, thereby the process procedure of the diaphragm can be reduced, and therefore the consistency of the diaphragm can be improved, and the production yield of the diaphragm is higher. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme in the embodiments of the utility model, the drawings needed to be used in the embodiment description will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained by the drawings according to the drawings without the creative labor for the person skilled in the art.

[0016] Figure 1 It is the structural schematic diagram of pole piece provided by the embodiment of the utility model;

[0017] Figure 2 It is the structural schematic diagram of base film provided by the embodiment of the utility model.

[0018] Among them, the above-mentioned drawing includes the following figure marks:

[0019] Current collector 10, active substance layer 20, protective layer 30, base film 40, connecting layer 50. DETAILED DESCRIPTION

[0020] The technical scheme in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model, and obviously, the described embodiments are only some embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without the creative labor belong to the protection scope of the utility model.

[0021] As Figure 1 And Figure 2 The embodiment of the utility model provides a kind of pole piece, and pole piece includes: current collector 10, the two sides of current collector 10 are provided with active substance layer 20;Protective layer 30, it is arranged in at least one active substance layer 20 side away from current collector 10, the side of protective layer 30 away from active substance layer 20 is used to be connected with base film 40.

[0022] The technical scheme of the utility model discloses, the active substance layer 20 is arranged in two layers of the current collector 10, and the protective layer 30 is arranged on at least one active substance layer 20, utilizes the protective layer 30 and the base film 40 to carry out the connection, so need not be coated on the surface of the base film 40 protective layer 30, to be able to reduce the process procedure of diaphragm, therefore is favorable to improve the consistency of diaphragm, make the production yield of diaphragm be higher.

[0023] In the application, the base film 40 specifically refers to the base material, which is usually made of polyethylene (PE) or polypropylene (PP). The diaphragm in the battery is mainly composed of the base material and the protective layer 30. In the application, the process of coating the protective layer 30 on the surface of the base material is cancelled and transferred to coating the protective layer 30 on the surface of the pole piece, thereby greatly reducing the production cost of the base film 40 and improving the product competitiveness.

[0024] In the application, the protective layer 30 is located outside the active substance layer 20, and one of its main functions is to isolate the active substance layer 20 from the external environment, preventing physical damage, chemical corrosion or pollution of the active substance layer 20. This helps to maintain the integrity and performance of the pole piece and ensures the normal operation of the battery. At the same time, the protective layer 30 can protect the active substance layer 20 from harmful factors such as mechanical stress, moisture and oxygen. For example, during the charging and discharging process of the battery, the active substance layer 20 may change in volume, and the protective layer 30 can provide a certain buffering effect to reduce the damage to the structure of the pole piece.

[0025] In addition, the presence of the protective layer 30 helps to enhance the overall stability of the pole piece. It can reduce the shedding and delamination of the active substance layer 20 during the charging and discharging process, thereby prolonging the service life of the battery. The protective layer 30 usually has good insulation performance, which can effectively prevent short circuit inside the battery. This is crucial for improving the safety of the battery, as short circuit can cause the battery to overheat, even causing fire or explosion. Good contact between the protective layer 30 and the base film 40 helps to improve the interface contact inside the battery, thereby reducing the internal resistance of the battery and improving the charging and discharging efficiency and performance of the battery. By reasonably designing the thickness and material of the protective layer 30, the overall structure of the battery can be optimized to be more compact and efficient. This helps to improve the energy density and power density of the battery, meeting the demand for high-performance batteries for modern electronic devices.

[0026] In an embodiment, the protective layer 30 comprises a ceramic layer. The presence of the ceramic layer can effectively increase the thermal shrinkage resistance of the polymer layer, preventing the polymer layer from thermal shrinkage during high-temperature baking. In some multilayer structure protective layers 30, the ceramic layer can act as a diffusion barrier to prevent elemental interdiffusion between the coating and the substrate, thereby protecting the substrate from damage. At the same time, the ceramic material has a high melting point and high thermal reflectivity, so the ceramic layer can significantly improve the heat resistance and thermal insulation of the current collector 10, allowing it to remain stable in high-temperature environments. Furthermore, the ceramic layer can act as an anti-corrosion and anti-oxidation layer, preventing the substrate from corroding and oxidizing, thereby extending the service life of the current collector 10.

[0027] Further, the ceramic material has good thermal stability at room temperature and in the service temperature range, and is not prone to phase change. Therefore, the ceramic layer can significantly improve the thermal stability of the current collector 10, allowing it to maintain stable performance in various temperature environments. The ceramic layer has high hardness and strength, which can increase the mechanical strength of the current collector 10, making it more resistant to external impact and extrusion.

[0028] In an embodiment, the thickness of the protective layer 30 is between 0.5 μm and 3 μm. A thinner protective layer 30 can reduce the overall weight and volume of the current collector 10, thereby providing more space for active materials inside the battery, which helps to improve the energy density of the battery. Within this thickness range, the contact resistance between the protective layer 30 and the current collector 10 is relatively small, which can ensure smooth transmission of current, thereby improving the electrical conductivity of the battery. A thinner protective layer 30 can respond more quickly to temperature changes and block short-circuit current in time, preventing the battery from overheating and causing thermal runaway. The protective layer 30 can isolate the current collector 10 from direct contact with corrosive substances in the external environment, thereby extending the service life of the current collector 10 and improving the overall safety of the battery. Despite its thinness, the protective layer 30 can still provide some mechanical support and protection to the current collector 10, preventing it from deforming or breaking when subjected to external forces. A thinner protective layer 30 can closely adhere to the surface of the current collector 10, forming a stable structure that helps to maintain the stability of the battery during charging and discharging. A thinner protective layer 30 means less protective material is used, thereby reducing production costs. Because the protective layer 30 is thin, the coating or deposition process can be faster and more efficient, which helps to improve the production efficiency of the battery.

[0029] In the present application, the thickness of the protective layer 30 can be set to 0.5 μm, 1 μm, or 13 μm, etc.

[0030] In an embodiment, the electrode sheet includes a positive electrode unit or a negative electrode unit. The positive electrode unit is typically made of lithium cobaltate, lithium nickelate, lithium manganate, or lithium ferrate, etc. These materials have high specific energy and specific power, enabling lithium-ion batteries to store more energy. The positive electrode material has excellent electrochemical reversibility, enabling repeated de- / intercalation of lithium without causing structural damage to the electrode, ensuring the stability and cycle life of the battery. Certain positive electrode materials, such as lithium cobaltate, have a high operating voltage, enabling lithium-ion batteries to provide higher output voltage, meeting the needs of high-power devices. The negative electrode unit is typically made of graphite, silicon-based materials, or lithium titanate, etc. These materials have good electrical conductivity and chemical stability, ensuring smooth electron transmission in the battery and long-term stability of the battery. Graphite and other negative electrode materials have high lithium intercalation capacity, enabling the storage of a large amount of lithium ions, thereby increasing the capacity and energy density of the battery. Graphite and other negative electrode materials are relatively inexpensive and easy to process, helping to reduce the production cost and improve the production efficiency of lithium-ion batteries.

[0031] The synergistic effect of positive and negative electrode units enables lithium-ion batteries to have high efficiency, meeting the needs of various electronic devices for high energy density and high power output. The stability and electrochemical reversibility of positive and negative electrode units ensure the long life and cycle stability of lithium-ion batteries, enabling the battery to be used for a long time without performance degradation. Through reasonable selection of positive and negative electrode materials and structural design, lithium-ion batteries can have high safety, avoiding safety hazards such as short circuit and overheating.

[0032] In an embodiment, the current collector 10 of the positive electrode unit includes aluminum. Aluminum is an excellent conductor, and its electrical conductivity fully meets the working requirements of the battery. High electrical conductivity ensures that the battery can effectively transmit current during operation, thereby improving the overall performance of the battery, such as charge / discharge efficiency and power output. During battery operation, the positive electrode current collector 10 needs to be immersed in the electrolyte for a long time. Aluminum material can resist the corrosion of electrolyte, maintaining long-term stability and reliability. This is crucial for extending the service life of the battery, as corrosion can cause the performance of the current collector 10 to decline, thereby affecting the overall performance of the battery.

[0033] Compared to other metal materials, aluminum is relatively low in price and easy to process and form. This makes aluminum an economically viable choice for the positive current collector 10 of lithium iron phosphate batteries and the like. Low cost helps to reduce the overall manufacturing cost of the battery, improving market competitiveness. Aluminum has a small density, so using aluminum as the positive current collector 10 helps to reduce the weight of the battery. Lightweight is one of the important goals pursued in the field of electric vehicles and energy storage systems, because reducing weight can improve the energy efficiency and endurance of the equipment. The chemical properties of lithium iron phosphate batteries require that the positive current collector 10 material must be compatible with them. Aluminum material performs well in this regard, as it can work cooperatively with other components of lithium iron phosphate batteries to ensure efficient and stable operation of the battery.

[0034] Furthermore, the flexibility and plasticity of aluminum make it easier to operate and assemble during the battery manufacturing process. This helps to simplify the production process and improve production efficiency. In summary, when aluminum is used as the positive current collector 10 of the positive electrode unit, it has the advantages of high electrical conductivity, corrosion resistance, cost-effectiveness, lightweight, good chemical compatibility, and easy processing and assembly.

[0035] In an embodiment, the negative current collector 10 of the negative electrode unit includes copper. Copper ranks second in electrical conductivity among metals, with extremely high electrical conductivity. This property ensures that the negative current collector 10 can effectively collect and transmit current, reducing the internal resistance of the battery and thus improving the charging and discharging efficiency and power output of the battery. Copper has good chemical stability and is not easily corroded by active substances in the battery. This means that during normal operation of the battery, the negative current collector 10 can maintain its mechanical strength and electrochemical properties, extending the service life of the battery. Compared to other metal materials, copper is relatively low in price, which makes it possible to significantly reduce the production cost of the battery by using copper as the negative current collector 10. This is of great significance for large-scale commercial applications. Copper is easy to process and form, and can meet the requirements of various shapes and sizes. This property allows the negative current collector 10 to be flexibly adapted to different battery designs and production processes, improving the manufacturing efficiency and flexibility of the battery.

[0036] At the same time, the negative electrode of the battery is usually made of carbon materials such as graphite. Copper has good compatibility with these negative electrode materials, ensuring tight contact and good electrical conductivity between the negative current collector 10 and the negative electrode material, thereby improving the overall performance of the battery. In lithium-ion batteries, the potential of the negative electrode is usually low, close to 0V. Copper is very stable at low potential and is not prone to chemical reactions or alloying reactions, so it is suitable as a negative current collector 10.

[0037] In an embodiment, the protective layer 30 is provided on both sides of the active material layer 20 of the current collector 10. The close combination between the protective layer 30 and the current collector 10 and the active material layer helps to form a more efficient electron transmission channel, thereby improving the conductivity of the battery. The design of the protective layer 30 can optimize the internal structure of the battery, reduce unnecessary space waste, and thus improve the energy density of the battery to a certain extent. The protective layer 30 has good mechanical stability and chemical stability, which can protect the current collector 10 and the active material layer from external factors and prolong the cycle life of the battery. The protective layer 30 acts as a barrier to prevent direct contact between the current collector 10 and the active material layer, reducing the risk of short circuit. The ceramic material has a high melting point and high thermal stability, which can protect the battery from damage in high-temperature environments and improve the heat resistance of the battery.

[0038] At the same time, the protective layer 30 can block the leakage of harmful substances (such as electrolyte) inside the battery to the outside, protecting the environment and human health. The protective layer 30 has excellent rigidity and hardness, which can maintain the stability of the battery structure and prevent the battery from deforming or breaking during charging and discharging. The presence of the protective layer 30 can reduce the thermal expansion coefficient of the battery during charging and discharging, maintaining the stability of the battery size. The protective layer 30 can be prepared by a simple coating or deposition process without complex processing, which helps to reduce production costs. The preparation process of the protective layer 30 can be combined with the existing battery production process to achieve efficient and continuous production, improving production efficiency.

[0039] In a second aspect, the embodiments of the utility model provide an electrode assembly, the electrode assembly includes: the pole piece; the base film 40 for being connected with the pole piece.

[0040] In an embodiment, the electrode assembly further includes a connecting layer 50, the connecting layer 50 is arranged on at least one side of the base film 40, and the base film 40 is connected with the pole piece through the connecting layer 50. In this way, the connection strength between the base film 40 and the pole piece can be improved.

[0041] In a third aspect, the embodiments of the utility model provide a core package, the core package includes the electrode assembly.

[0042] The technical scheme of the utility model is applied to the two layers of the current collector 10 are provided with the active material layer 20, and the protective layer 30 is arranged on at least one active material layer 20, and the protective layer 30 is connected with the base film 40, so that the surface of the base film 40 does not need to be coated with the protective layer 30, thereby the process procedure of the diaphragm can be reduced, and therefore the consistency of the diaphragm can be improved, and the production yield of the diaphragm is higher.

[0043] The application further provides a battery module, which comprises the core package. The specific structure of the core package is referred to the above embodiments. Since all the technical solutions of the above embodiments are adopted in the battery module, all the beneficial effects brought by the technical solutions of the above embodiments are at least achieved, which will not be repeated here.

[0044] The application further provides a battery pack, which comprises the battery module. The specific structure of the battery module is referred to the above embodiments. Since all the technical solutions of the above embodiments are adopted in the battery pack, all the beneficial effects brought by the technical solutions of the above embodiments are at least achieved, which will not be repeated here.

[0045] In addition, the application further provides a power consuming device, which comprises the battery pack. The specific structure of the battery pack is referred to the above embodiments. Since all the technical solutions of the above embodiments are adopted in the power consuming device, all the beneficial effects brought by the technical solutions of the above embodiments are at least achieved, which will not be repeated here.

[0046] It can be understood that the power consuming device includes but is not limited to electric toys, electric tools, electric vehicles, automobiles, ships, spacecraft, etc. Among them, the electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric plane toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc. The automobile can be a fuel automobile, a gas automobile, and a new energy automobile.

[0047] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0048] The foregoing description, for purposes of clarity, describes the present application in terms of its components, processes and operations. Such descriptions and representations are the means used by those skilled in the art of describing the structural and functional necessities of and changes to the present application, but are not meant to limit the present application to a particular embodiment. Also, the various embodiments of the present application presented are not necessarily the only ones in which the present application can be practiced. The embodiments presented are intended to convey the scope of the present application, its energy saving and cost saving advantages, and its intended advantages to those skilled in the art. Numerous adaptations and modifications can be practiced without departing from the scope of the present application. Accordingly, the scope of the present application is to be indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalents are intended to be embraced therein.

[0049] In the description of the present application, it is to be understood that the specific location or position relationships indicated by directional terms, such as "front", "back", "up", "down", "left", "right", "horizontal", "vertical", "top", "bottom", and the like, are based on the orientation or position relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application. The orientation terms "inner" and "outer" refer to the inner and outer of the profile of the components themselves.

[0050] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper", and the like can be used herein to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the devices described in the drawings. For example, if the devices in the drawings are inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0051] In addition, it should be noted that the use of the terms "first", "second", and the like to describe various components does not limit the corresponding components in any way, and the above terms do not have special meanings unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

[0052] The above descriptions are only the preferred embodiments of the present application, and are not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pole piece, characterized in that, The pole piece comprises: a current collector, two sides of the current collector being provided with active material layers; a protective layer, provided on at least one side of the active material layer away from the current collector, the side of the protective layer away from the active material layer being used for connecting with a base film.

2. The pole piece of claim 1, wherein The protective layer comprises a ceramic layer.

3. The pole piece of claim 1, wherein The thickness of the protective layer is between 0.5 μm and 3 μm.

4. The pole piece of claim 1, wherein The pole piece comprises a positive electrode unit or a negative electrode unit.

5. The pole piece of claim 4, wherein The current collector of the positive electrode unit comprises aluminum.

6. The pole piece of claim 4, wherein The current collector of the negative electrode unit comprises copper.

7. The pole piece of claim 1, wherein The active material layers on both sides of the current collector are provided with the protective layer.

8. An electrode assembly characterized by, The electrode assembly comprises: the pole piece as claimed in any one of claims 1-7; a base film, used for connecting with the pole piece.

9. The electrode assembly of claim 8, wherein, The electrode assembly further comprises a connecting layer, provided on at least one side of the base film, the base film being connected with the pole piece through the connecting layer.

10. A core pack characterized by, The core package comprises the electrode assembly as claimed in any one of claims 8 and 9.

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