Bipolar battery and electric equipment

Abstract

The utility model provides a bipolar battery and electric equipment. Relates to the technical field of batteries. The bipolar battery comprises a battery cell body. The battery cell body comprises a plurality of stacked pole pieces, and a diaphragm is arranged between every two adjacent pole pieces. The liquid absorption rate of the diaphragm is greater than 100%, and the liquid retention rate of the diaphragm is greater than 60%. And the diaphragm is used for storing the electrolyte, so that in the assembly process of the bipolar battery, the pole piece and the diaphragm in which the electrolyte is stored only need to be assembled without additionally arranging a liquid injection hole, the problem of difficulty in liquid injection of the bipolar battery is solved, and the use performance of electric equipment is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a bipolar battery and a power consumption device. BACKGROUND

[0002] A bipolar battery is a battery in which positive and negative active materials are coated on both sides of the same current collector. When two battery cells are connected in series, one side of the current collector serves as the negative electrode of one battery cell, and the other side serves as the positive electrode in the adjacent battery cell.

[0003] In related technologies, a special liquid injection hole structure is designed on the battery. When injecting electrolyte into the battery, the operator first injects electrolyte into the battery through the liquid injection hole, and then seals the liquid injection hole to avoid leakage of the electrolyte.

[0004] However, the existing battery cell has the problem of difficult liquid injection process. UTILITY MODEL CONTENT

[0005] The present application provides a bipolar battery and a power consumption device, which solves the problem of difficult liquid injection of the bipolar battery and improves the use performance of the power consumption device.

[0006] In a first aspect, the embodiments of the present application provide a bipolar battery, comprising:

[0007] The cell body includes a plurality of pole pieces stacked and arranged, and a diaphragm is arranged between adjacent pole pieces.

[0008] The liquid absorption rate of the diaphragm is greater than 100%, and the liquid retention rate of the diaphragm is greater than 60%.

[0009] In some embodiments of the present application, the diaphragm has a liquid storage part and / or a liquid-wettable part.

[0010] In some embodiments of the present application, the diaphragm includes a diaphragm body, and the diaphragm body has a porous structure, and the porous structure forms the liquid storage part.

[0011] In some embodiments of the present application, the diaphragm further includes a doping substance, and the diaphragm body and the doping substance form a composite.

[0012] In some embodiments of the present application, the doping substance includes inorganic particles, metal organic frameworks or cellulose.

[0013] In some embodiments of the present application, the doping substance has a hydrophilic functional group, and the hydrophilic functional group forms the liquid-wettable part.

[0014] And / or, the diaphragm body has a hydrophilic functional group, and the hydrophilic functional group forms the liquid-wettable part.

[0015] In some embodiments of the present application, the hydrophilic functional group includes a hydroxyl group or a carboxyl group.

[0016] In some embodiments of this application, the diaphragm includes a diaphragm body and a coating layer, with the coating layer disposed on both sides of the diaphragm body in the thickness direction.

[0017] The diaphragm body forms the liquid storage section.

[0018] The coating layer forms a liquid reservoir and / or a liquid-receptive region.

[0019] In some embodiments of this application, the material of the liquid reservoir includes polypropylene, polyethylene, or polyimide.

[0020] In some embodiments of this application, the inorganic particles include boehmite or silicon dioxide.

[0021] And / or, the metal-organic framework includes the zeolite imidazole framework.

[0022] In some embodiments of this application, the plurality of electrodes includes a first electrode, at least one bipolar electrode, and a second electrode.

[0023] In some embodiments of this application, the bipolar electrode includes a current collector, a first active layer, and a second active layer; the first active layer and the second active layer are respectively disposed on opposite sides of the current collector in the thickness direction; the first active layer and the second active layer have different polarities.

[0024] A diaphragm is provided on the side of the first active layer facing away from the current collector, and / or a diaphragm is provided on the side of the second active layer facing away from the current collector.

[0025] In some embodiments of this application, the first electrode and the first active layer are disposed opposite to each other; the second electrode and the second active layer are disposed opposite to each other.

[0026] Furthermore, a diaphragm is provided between the first electrode and the first active layer; a diaphragm is provided between the second electrode and the second active layer.

[0027] In some embodiments of this application, the bipolar battery further includes a seal connected to an adjacent electrode and located on the outer periphery of the electrode and the separator.

[0028] In some embodiments of this application, the seal is disposed at the edge of one of two adjacent electrodes and is sealed to the other of the two adjacent electrodes.

[0029] In some embodiments of this application, the sealing element includes a first sealing element and a second sealing element. The first sealing element is disposed at a portion of the edge of one of the two adjacent electrode pieces, and the second sealing element is disposed at a portion of the edge of the other of the two adjacent electrode pieces. The first sealing element and the second sealing element are joined together to surround the outer periphery of the two adjacent electrode pieces.

[0030] In some embodiments of this application, along the thickness direction of the diaphragm, the sum of the thicknesses of the active material of the first electrode, the diaphragm, and the first active layer is equal to the extension length of the seal.

[0031] And / or, the sum of the thicknesses of the active material of the second electrode, the diaphragm, and the second active layer is equal to the extension length of the seal.

[0032] And / or, the sum of the thicknesses of the first active layer of one of the two adjacent bipolar electrodes, the second active layer of the other of the two adjacent bipolar electrodes, and the diaphragm is equal to the extension length of the seal.

[0033] In some embodiments of this application, the sealant includes tab-like adhesive and / or metal adhesive.

[0034] Secondly, embodiments of this application provide an electrical device including a bipolar battery.

[0035] The bipolar battery and electrical device provided in this application include a cell body. The cell body includes at least two stacked electrodes, with a separator between adjacent electrodes. The separator has a liquid absorption rate greater than 100% and a liquid retention rate greater than 60%. The separator stores the electrolyte. Thus, during the bipolar battery assembly process, only the electrodes and the electrolyte-storing separator need to be assembled, eliminating the need for additional injection holes. The bipolar battery provided in this application eliminates the steps of injecting and sealing the injection holes in traditional bipolar battery manufacturing methods, solving the problem of difficult electrolyte injection in bipolar batteries. Furthermore, the electrolyte stored in the separator meets the cycle and power performance requirements of the bipolar battery. Simultaneously, because the electrolyte is stored in the separator, there is not much free electrolyte, avoiding electrolyte waste and improving the performance of the electrical device. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0037] Figure 1 A schematic diagram of the structure of the bipolar battery provided in the embodiments of this application. Figure 1 ;

[0038] Figure 2 A schematic diagram of the structure of the bipolar battery provided in the embodiments of this application. Figure 2 ;

[0039] Figure 3 A schematic diagram illustrating the fabrication process of the bipolar battery provided in this application embodiment;

[0040] Figure 4 A schematic diagram of the electrode structure of the bipolar battery provided in the embodiments of this application. Figure 1 ;

[0041] Figure 5 A schematic diagram of the electrode structure of the bipolar battery provided in the embodiments of this application. Figure 2 .

[0042] Explanation of reference numerals in the attached figures:

[0043] 100: Bipolar electrode;

[0044] 110: Current collector; 120: First active layer; 130: Second active layer;

[0045] 200: Diaphragm;

[0046] 300: Electrolyte;

[0047] 400: Seal; 410: First seal; 420: Second seal;

[0048] 500: terminal;

[0049] 600: First electrode; 610: First current collector; 620: Third active layer;

[0050] 700: Second electrode; 710: Second current collector; 720: Fourth active layer.

[0051] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0052] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0053] Bipolar batteries are batteries in which the positive and negative active materials are coated on both sides of the same current collector. When two battery cells are connected in series, one side of the current collector serves as the negative electrode of one battery cell, while the other side serves as the positive electrode in the adjacent battery cell. This structure reduces inefficient battery mounting space and lowers the electrical connection impedance between battery cells, giving bipolar batteries advantages such as high voltage, high energy density, and high overcurrent capability.

[0054] In related technologies, depending on the type of electrolyte, the electrolytes in bipolar batteries include solid electrolytes and liquid electrolytes. When a bipolar battery uses an all-solid-state electrolyte, the problem of difficult liquid filling and sealing in bipolar batteries can be fundamentally avoided. However, all-solid-state electrolytes themselves have many technical problems that are difficult to overcome in a short period of time, such as conductivity that is difficult to match that of liquid electrolytes, and poor wettability with the electrode leading to high interfacial impedance.

[0055] For bipolar batteries using liquid electrolytes, current methods often involve designing a dedicated injection hole structure on each battery cell. Electrolyte is injected through these holes and then sealed. While this method achieves electrolyte injection, the design and fabrication of the injection holes are challenging due to the large area and extremely small gaps between the electrodes in bipolar batteries. Furthermore, the high requirements for electrolyte sealing within the battery cells necessitate additional sealing of the injection holes, a process that is both difficult and complex. For instance, electrolyte contamination near the injection holes can weaken the seal. Therefore, existing bipolar batteries suffer from the complexity and difficulty of electrolyte injection.

[0056] In view of this, embodiments of this application provide a bipolar battery and an electrical device. The bipolar battery includes a cell body. The cell body includes at least two stacked electrodes, with a separator disposed between adjacent electrodes. The separator has a liquid absorption rate greater than 100% and a liquid retention rate greater than 60%. The separator is used to store electrolyte. Thus, during the assembly process of the bipolar battery, the electrodes and the separator storing electrolyte are assembled, eliminating the need for additional injection holes. The bipolar battery provided by this application eliminates the steps of injecting and sealing the injection holes in traditional bipolar battery manufacturing methods, solving the problem of difficult electrolyte injection in bipolar batteries. In addition, the electrolyte stored in the separator meets the cycle and power performance requirements of the bipolar battery. At the same time, since the electrolyte is stored in the separator, there is not much free electrolyte, avoiding electrolyte waste and improving the performance of the electrical device.

[0057] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0058] Firstly, referring to Figures 1 to 5 As shown, this application embodiment provides a bipolar battery, including:

[0059] The battery cell body includes multiple stacked electrodes, with a separator 200 disposed between adjacent electrodes.

[0060] Among them, the liquid absorption rate of diaphragm 200 is greater than 100%, and the liquid retention rate of diaphragm 200 is greater than 60%.

[0061] For example, the cell body is the core component of the bipolar battery, responsible for the energy storage and conversion of the bipolar battery. The bipolar battery includes multiple electrodes, which are stacked sequentially, with a separator 200 disposed between adjacent electrodes. The separator 200 and the electrodes form a complete electrochemical unit.

[0062] Electrodes are the electrodes of a bipolar battery, including positive electrodes, negative electrodes, and bipolar electrodes. Electrodes are responsible for the battery's electrochemical reactions, storing and releasing electrical energy. Bipolar battery electrodes are designed with a large surface area to improve the battery's energy density and power output.

[0063] The separator 200 is a key component disposed between adjacent electrodes. The main function of the separator 200 is to prevent direct contact between the positive and negative electrodes to avoid short circuits, while allowing ions to pass through to maintain the electrochemical reaction of the bipolar battery.

[0064] The bipolar battery provided in this application embodiment sets the liquid absorption rate of the separator 200 to be greater than 100% and the liquid retention rate of the separator 200 to be greater than 60%. The separator 200 is used to store the electrolyte 300, eliminating the steps of filling and sealing the liquid filling hole in the traditional bipolar battery manufacturing method.

[0065] The bipolar battery provided in this application embodiment satisfies the cycle and power performance of a bipolar battery without having too much free electrolyte 300, thus avoiding waste of electrolyte 300.

[0066] The current collector 110 of the bipolar battery is a copper-aluminum composite foil. In traditional electrolyte injection methods, the electrolyte 300 exists in a free state before formation. When a large restraining force is applied to the bipolar battery, the electrolyte 300 accumulates at the edge of the electrode. This not only causes uneven distribution of the electrolyte 300 inside the bipolar battery, leading to problems such as lithium dendrites, but also exacerbates the corrosion of the sealed area by the high pressure and high electrolyte 300 density at the electrode edge, causing battery failure. In the bipolar battery provided in this application embodiment, the electrolyte 300 is either absorbed into the interior by the separator 200 or adheres to the surface of the separator 200. It has lower flowability and a more uniform thickness distribution. A larger restraining force can be applied with a restraining clamp immediately after sealing, which facilitates the effective utilization of battery capacity and the uniform formation of the solid electrolyte interphase (SEI) film during the formation process, while also extending the effective sealing time of the bipolar battery.

[0067] For example, the diaphragm 200 is weighed using an electronic balance and recorded as the first weight. (Refer to...) Figure 3As shown, the diaphragm 200 is immersed in the electrolyte 300. After a certain period of time, the diaphragm 200 is removed, and the diaphragm 200 with the adsorbed electrolyte 300 is weighed. This mass of the diaphragm 200 with the adsorbed electrolyte 300 is recorded as the second weight. After the diaphragm 200 with the adsorbed electrolyte 300 is left to stand in the external environment for a period of time, it is weighed again and recorded as the third weight. In this way, based on the weight of the diaphragm 200 at different stages, the liquid absorption rate and liquid retention rate of the diaphragm 200 are calculated.

[0068] Wherein, the liquid absorption rate % = (second weight - first weight) / first weight × 100%.

[0069] Liquid retention rate % = (Third weight - First weight) / (Second weight - First weight) × 100%.

[0070] In some embodiments, the liquid absorption rate of the diaphragm 200 can reach more than 200%, and the liquid retention capacity is greater than 60%.

[0071] For example, the cell body leads out the electrode plates through terminal 500.

[0072] As one possible implementation, the diaphragm 200 has a liquid storage section and / or a liquid-receptive section.

[0073] For example, the function of the electrolyte reservoir is to store electrolyte 300. The reservoir provides a dedicated area to contain the electrolyte 300, thus eliminating the steps of filling and sealing the filling holes in the traditional bipolar battery manufacturing process by pre-storing the electrolyte 300 in the separator 200. This design allows the separator 200, already containing the electrolyte 300, to be placed directly between adjacent electrodes during bipolar battery assembly, greatly simplifying the production process and improving production efficiency. Simultaneously, by effectively storing the electrolyte 300, the reservoir reduces the presence of free electrolyte 300, lowering the risk of electrolyte leakage and waste.

[0074] For example, the function of the hydrophilic portion is to adsorb the electrolyte 300. Through its material properties, the hydrophilic portion can rapidly absorb and retain the electrolyte 300. The design of the hydrophilic portion improves the uniformity of electrolyte 300 distribution on the separator 200, promoting a uniform electrochemical reaction. This adsorption capacity helps to form a uniform solid electrolyte interphase (SEI) film during battery formation, improving the stability and lifespan of the bipolar battery.

[0075] In some embodiments, the diaphragm 200 has a liquid reservoir.

[0076] In other embodiments, the diaphragm 200 has a hydrophilic portion.

[0077] In some other embodiments, the diaphragm 200 has a liquid reservoir and a liquid-receptive portion.

[0078] In one feasible implementation, the diaphragm 200 includes a diaphragm body having a porous structure that forms a liquid storage section.

[0079] For example, the membrane body is the main structural part of the membrane 200, responsible for providing mechanical support. The porous structure of the membrane body provides more pathways for the storage and conduction of the electrolyte 300 by increasing the surface area and porosity. This porous structure forms a reservoir that can accommodate and retain a large amount of electrolyte 300, ensuring a sufficient supply of electrolyte 300 during the operation of the bipolar battery.

[0080] In some embodiments, the membrane body is prepared by electrospinning. The membrane body is fibrous and has a porous structure. Electrospinning is a technique for preparing fibrous structures by stretching a polymer solution or melt into fine fibers using electrostatic force. This method can produce membrane bodies with highly controllable fiber diameters and porous structures, optimizing their liquid absorption and retention properties. The fibrous membrane body prepared by electrospinning has high porosity and excellent mechanical properties.

[0081] As one possible implementation, the diaphragm 200 also includes a dopant, and the diaphragm body and the dopant form a composite.

[0082] In some embodiments, the membrane body is heated above its melting point, causing it to melt. This process places the membrane body in a liquid state, allowing for thorough mixing with the dopant. The dopant is then added to the molten membrane body. The dopant is uniformly dispersed within the liquid membrane body. The mixed material is then cooled and solidified. During solidification, the dopant is fixed within the structure of the membrane body, forming a stable composite.

[0083] In other embodiments, the membrane body is dissolved in a solvent. This forms a mixture between the membrane body and the solvent. A dopant is then added to the mixture. The dopant is uniformly dispersed in the mixture. The mixture containing the dopant is then evaporated. During evaporation, the solvent evaporates, and the dopant is fixed within the structure of the membrane body, forming a stable composite.

[0084] The addition of dopants can alter the microstructure of the membrane, creating a porous structure, such as a multi-porous structure. The presence of a porous structure increases the electrolyte storage capacity of the membrane 200, ensuring a sufficient supply of electrolyte 300 during battery operation, thereby maintaining ionic conductivity.

[0085] The dopants may possess hydrophilic properties, meaning they can attract and retain moisture or electrolyte 300. By enhancing the hydrophilicity of the separator 200, the electrolyte 300 can be more rapidly adsorbed and uniformly distributed within the separator 200, promoting a uniform electrochemical reaction. The separator 200 prepared through this process possesses both hydrophilic and electrolyte storage functions. This composite structure of the separator 200 effectively manages the electrolyte 300, reduces leakage risk, and improves the overall performance and safety of the bipolar battery.

[0086] As one feasible implementation, the dopant material includes inorganic particles, metal-organic frameworks, or cellulose.

[0087] For example, inorganic particles can improve the porous structure of the membrane body, increasing the storage capacity and ionic conductivity of the electrolyte 300.

[0088] Metal-organic frameworks (MOFs) are porous materials formed by the coordination bonds between metal ions or clusters and organic ligands, possessing high specific surface area and tunable pore structure. The porous structure of MOFs helps improve the electrolyte adsorption capacity and ion conduction pathways of the membrane 200, promoting uniform electrochemical reactions.

[0089] Cellulose is a natural polysaccharide polymer with biocompatibility and environmental friendliness. Using cellulose in the coating layer can improve the hydrophilicity of the membrane 200 and the adsorption capacity of the electrolyte 300. Simultaneously, the structure of cellulose can enhance the mechanical flexibility and stability of the coating layer.

[0090] As one feasible implementation, the dopant includes inorganic particles, metal-organic framework, and cellulose, with the mass ratio of inorganic particles, metal-organic framework, and cellulose being (0-100):(0-100):(0-100).

[0091] For example, the proportions of the three dopants—inorganic particles, metal-organic framework, and cellulose—can be flexibly adjusted according to specific application needs and performance requirements. When it is necessary to improve the mechanical strength and thermal stability of the membrane 200, the proportions of inorganic particles and cellulose can be increased. Inorganic particles provide structural support and thermal resistance. Cellulose provides mechanical strength and chemical stability.

[0092] To improve the ionic conductivity of the membrane 200, the proportion of the metal-organic framework can be increased. The porous structure and high specific surface area of ​​the metal-organic framework help improve the adsorption and ion conduction of the electrolyte 300.

[0093] As one feasible implementation method, the dopant material has hydrophilic functional groups, which form a lyophilic part.

[0094] In some embodiments, the membrane body has hydrophilic functional groups, which form a hydrophilic portion.

[0095] For example, hydrophilic functional groups refer to chemical groups that can form hydrogen bonds or other polar interactions with water or electrolyte molecules.

[0096] Hydrophilic functional groups significantly enhance the hydrophilicity of the membrane 200, making it easier to adsorb and retain moisture or electrolyte 300. In the membrane 200, the hydrophilic functional groups on the dopant form lyophilic regions. These regions can rapidly adsorb electrolyte 300, ensuring its uniform distribution within the membrane 200. The presence of these lyophilic regions helps improve the utilization efficiency of the electrolyte 300, promotes uniform electrochemical reactions, and reduces localized concentration differences.

[0097] By introducing hydrophilic functional groups, the ability of the membrane 200 to adsorb electrolyte 300 is enhanced, ensuring that the bipolar battery has ionic conductivity during startup and operation.

[0098] In some embodiments, when the dopant includes cellulose, the cellulose contains a large number of hydroxyl groups, which endow the cellulose with good hydrophilicity. This hydrophilicity helps to improve the electrolyte 300 adsorption capacity and wettability of the membrane 200, ensuring that the electrolyte 300 can be rapidly and uniformly distributed in the membrane 200.

[0099] As one possible implementation, the hydrophilic functional group includes a hydroxyl or a carboxyl group.

[0100] For example, the hydroxyl group is a polar functional group capable of forming hydrogen bonds with water molecules or polar molecules in the electrolyte 300. Introducing hydroxyl groups into the membrane 200 can significantly improve the hydrophilicity of the material, enabling it to rapidly adsorb and retain the electrolyte 300. The presence of hydroxyl groups helps improve the wettability and distribution of the electrolyte 300, promoting uniform electrochemical reactions.

[0101] In the membrane 200, carboxyl groups can enhance the material's hydrophilicity and the electrolyte 300's adsorption capacity. The introduction of carboxyl groups may also provide additional chemical stability, helping the membrane 200 resist corrosion and degradation by the electrolyte 300.

[0102] By introducing hydroxyl and / or carboxyl groups into the dopant, the hydrophilic properties of the separator 200 are significantly improved, ensuring that the electrolyte 300 can be rapidly and uniformly distributed within the separator 200. This design reduces electrolyte waste and leakage risk, improving battery safety and performance stability.

[0103] As one feasible implementation, the diaphragm 200 includes a diaphragm body and a coating layer, the coating layer being disposed on both sides of the diaphragm body in the thickness direction.

[0104] The diaphragm body forms the liquid storage section.

[0105] The coating layer forms a liquid reservoir and / or a liquid-receptive region.

[0106] For example, the membrane body is the core structural part of the membrane 200. The membrane body forms liquid storage sections, which effectively store electrolyte 300 by increasing porosity and surface area, ensuring that the bipolar battery has a sufficient supply of electrolyte 300 during operation.

[0107] The coating layer is disposed on both sides of the membrane body in the thickness direction. The coating layer can further enhance the liquid storage capacity of the membrane 200 and store more electrolyte 300 by increasing surface porosity and adsorption capacity.

[0108] The coating layer may include hydrophilic materials or functional groups such as hydroxyl and carboxyl groups to improve the hydrophilicity of the membrane 200. This ensures that the electrolyte 300 can be rapidly adsorbed and uniformly distributed. The coating layer can also provide additional mechanical strength and thermal stability, protecting the membrane body from physical and chemical damage.

[0109] As one possible implementation, the material of the diaphragm body includes polypropylene, polyethylene, or polyimide.

[0110] For example, polypropylene possesses mechanical strength and chemical stability. Polypropylene can provide ionic conductivity in bipolar batteries. Its heat resistance and chemical resistance make it ideal for bipolar battery separators 200.

[0111] Polyethylene has flexibility and chemical stability, and polyethylene diaphragms 200 are low-cost and easy to process.

[0112] Polyimide is a polymer. It can withstand high stress and high pressure conditions. Polyimide exhibits good resistance to acids, alkalis, and organic solvents. It also possesses electrical insulating properties, effectively preventing internal short circuits in batteries.

[0113] As one feasible implementation, the membrane body is made of polypropylene, polyethylene, and polyimide, with the mass ratio of polypropylene, polyethylene, and polyimide being 0-100:0-100:0-100.

[0114] For example, the proportions of polypropylene, polyethylene, and polyimide can be flexibly adjusted according to specific application needs and performance requirements. When it is necessary to improve the mechanical strength and abrasion resistance of the diaphragm 200, the proportion of polypropylene can be increased. When it is necessary to improve the flexibility of the diaphragm 200, the proportion of polyethylene can be increased. When it is necessary to improve the heat resistance and chemical stability of the diaphragm 200, the proportion of polyimide can be increased.

[0115] As one feasible implementation, the inorganic particles include boehmite or silica.

[0116] In some embodiments, the metal-organic framework includes a zeolite imidazole framework.

[0117] For example, boehmite is a hydrous alumina mineral with thermal stability and mechanical strength. The microstructure of boehmite helps to enhance the electrolyte 300 adsorption capacity of the coating.

[0118] Silica is a commonly used inorganic material. Its porous structure helps improve the storage capacity and ionic conductivity of electrolyte 300.

[0119] The porous structure of the zeolite imidazole framework helps to improve the electrolyte 300 adsorption capacity and ion conduction pathway of the coating, promoting a uniform electrochemical reaction.

[0120] As one feasible implementation, the inorganic particles include boehmite and silicon dioxide, with a mass ratio of boehmite to silicon dioxide of 0-100:0-100.

[0121] For example, the properties of the coating can be optimized according to specific application needs and performance requirements. When improved thermal stability of the coating is required, the proportion of boehmite can be increased. Boehmite has good heat resistance and remains stable under high temperature conditions. Boehmite also provides mechanical strength, so its content can be increased when enhanced structural integrity of the coating is needed.

[0122] Silica possesses chemical stability and a porous structure, which contributes to improving the storage capacity and ionic conductivity of electrolyte 300. Therefore, the proportion of silica can be increased when these properties require enhancement.

[0123] As one possible implementation, the plurality of electrodes includes a first electrode 600, at least one bipolar electrode 100, and a second electrode 700.

[0124] For example, the first electrode 600 serves as one end of the battery and can be either a positive electrode or a negative electrode.

[0125] The bipolar electrode 100 is a key component of the bipolar battery. Each bipolar electrode 100 has two sides, one as the positive electrode and the other as the negative electrode. The bipolar electrode 100 connects adjacent cell units in the battery, allowing current to flow directly inside the battery, thereby reducing the complexity of external connections and resistance losses.

[0126] The second electrode 700 serves as the other terminal of the battery, opposite to the first electrode 600, thus completing the battery's circuitry.

[0127] There can be multiple bipolar electrodes 100, which are stacked sequentially. One bipolar electrode 100 at one end is positioned opposite to the first electrode 600, and one bipolar electrode 100 at the other end is positioned opposite to the second electrode 700.

[0128] As one feasible implementation, the bipolar electrode 100 includes a current collector 110, a first active layer 120 and a second active layer 130; the first active layer 120 and the second active layer 130 are respectively disposed on both sides of the current collector 110 in the thickness direction; the first active layer 120 and the second active layer 130 have different polarities.

[0129] A diaphragm 200 is provided on the side of the first active layer 120 facing away from the current collector 110, and / or a diaphragm 200 is provided on the side of the second active layer 130 facing away from the current collector 110.

[0130] For example, the current collector 110 is a core component of the bipolar electrode 100. The current collector 110 can be a copper-aluminum composite foil used to collect and conduct current.

[0131] The first active layer 120 is disposed on one side of the current collector 110 and has a specific polarity. For example, the first active layer 120 can be a positive electrode active layer. The first active layer 120 can also be a negative electrode active layer.

[0132] The second active layer 130 is disposed on the other side of the current collector 110 and has the opposite polarity to the first active layer 120. For example, the first active layer 120 can be a positive electrode active layer, and the second active layer 130 can be a negative electrode active layer. This double-sided active layer design can improve the energy density and power output of the battery.

[0133] A separator 200 is provided on the side of the first active layer 120 away from the current collector 110. This configuration can prevent the first active layer 120 from directly contacting other battery components, avoiding short circuits and other electrochemical instabilities.

[0134] A separator 200 is provided on the side of the second active layer 130 opposite to the current collector 110. Similarly, this configuration protects the second active layer 130 and ensures the safety and stability of the battery.

[0135] When multiple electrodes include a first electrode 600, a bipolar electrode 100, and a second electrode 700, the first electrode 600 and the first active layer 120 are arranged opposite to each other; the second electrode 700 and the second active layer 130 are arranged opposite to each other.

[0136] A diaphragm 200 is provided between the first electrode 600 and the first active layer 120; a diaphragm 200 is provided between the second electrode 700 and the second active layer 130.

[0137] For example, the first electrode 600 is used to connect to an external circuit. The first electrode 600 and the first active layer 120 are disposed opposite each other, meaning they are arranged face to face. This arrangement allows ions to move between the first electrode 600 and the first active layer 120 during charging and discharging. A separator 200 is disposed between the first electrode 600 and the first active layer 120. The separator prevents direct contact and avoids short circuits, while allowing ions to pass through to maintain the electrochemical reaction of the battery.

[0138] The second electrode 700 and the second active layer 130 are arranged opposite each other, meaning they are face-to-face. This arrangement allows ions to move between the second electrode 700 and the second active layer 130 during charging and discharging. A separator 200 is disposed between the second electrode 700 and the second active layer 130. The separator's function is to prevent direct contact and avoid short circuits, while allowing ions to pass through to maintain the battery's electrochemical reactions.

[0139] In some embodiments, the first electrode 600 can be a positive electrode, and the second electrode 700 can be a negative electrode.

[0140] In some other embodiments, the first electrode 600 can be a negative electrode, and the second electrode 700 can be a positive electrode.

[0141] As one possible implementation, the bipolar battery also includes a seal 400 connected to an adjacent electrode and located on the outer periphery of the electrode and the separator 200.

[0142] For example, the seal 400 provides a physical barrier to prevent electrolyte 300 from leaking from the bipolar battery into the external environment. By isolating the internal components of the bipolar battery, such as the electrodes and separator 200, from the external environment, the seal 400 prevents the intrusion of moisture, oxygen, and other potential contaminants. The seal 400 helps maintain the structural integrity of the bipolar battery, preventing component displacement or damage during operation due to mechanical stress or thermal expansion.

[0143] As one possible implementation, the seal 400 is disposed at the edge of one of the two adjacent electrodes and is sealed to the other of the two adjacent electrodes.

[0144] For example, the seal 400 is disposed at the edge of one of the two adjacent electrodes, meaning it is arranged along the outer peripheral edge of one of the two adjacent electrodes. The seal 400 is sealed to the other of the two adjacent electrodes, forming a complete closed system. This connection method ensures a tight seal between the adjacent electrodes, preventing electrolyte 300 leakage and the intrusion of external contaminants.

[0145] By placing a seal 400 at the edge of one of two adjacent electrodes, leakage of electrolyte 300 from the inside of the battery to the outside can be effectively prevented. The seal 400 provides additional mechanical support, helping to maintain the structural integrity of the bipolar battery, especially under conditions of thermal expansion or mechanical stress. The presence of the seal 400 helps protect the internal components of the bipolar battery from external environmental influences such as moisture, oxygen, and other chemicals.

[0146] In one feasible implementation, the seal 400 includes a first seal 410 and a second seal 420. The first seal 410 is disposed at a portion of the edge of one of the two adjacent electrodes, and the second seal 420 is disposed at a portion of the edge of the other of the two adjacent electrodes. The first seal 410 and the second seal 420 are joined together to surround the outer periphery of the two adjacent electrodes.

[0147] For example, a first seal 410 is disposed at a portion of the edge of one of two adjacent electrodes, and a second seal 420 is disposed at a portion of the edge of the other of the two adjacent electrodes. The first seal 410 and the second seal 420 are joined together to surround the outer periphery of the adjacent electrodes. This joint design ensures the complete sealing of the entire battery assembly, preventing electrolyte 300 leakage and the intrusion of external contaminants.

[0148] By using two independent first seals 410 and second seals 420, different bipolar battery designs and size requirements can be accommodated more flexibly. The spliced ​​design provides an additional sealing layer, further improving the leak-proof performance of the bipolar battery. The presence of seal 400 helps protect the battery's internal components from external environmental influences such as moisture, oxygen, and other chemicals.

[0149] In some embodiments, refer to Figure 4 and Figure 5 As shown, one of two adjacent electrode plates is square in shape, and the other of the two adjacent electrode plates is also square in shape. Along a first direction, a first sealing element 410 is provided at both ends of one of the two adjacent electrode plates. Along a second direction, a second sealing element 420 is provided at both ends of one of the two adjacent electrode plates. The first direction and the second direction are perpendicular. Adjacent electrode plates are connected by the first sealing element 410 and the second sealing element 420. (The first direction is referenced...) Figure 4 The direction indicated by X in the middle. The second direction is referenced. Figure 5 The direction shown in Y.

[0150] As one feasible implementation, along the thickness direction of the diaphragm 200, the sum of the thicknesses of the active material of the first electrode 600, the diaphragm 200, and the first active layer is equal to the extension length of the seal 400.

[0151] Exemplarily, the first electrode 600 includes a first current collector 610 and a third active layer 620, the active material of the first electrode 600 forming the third active layer 620. By setting the sum of the thicknesses of the third active layer 620, the separator 200, and the first active layer 120 to be equal to the extension length of the seal 400, it can be ensured that the seal 400 completely covers the sides of the cell body during assembly, preventing any potential leakage paths. This matching design helps maintain the structural integrity of the bipolar battery during operation, preventing seal failure due to thermal expansion or mechanical stress.

[0152] In some embodiments, the sum of the thicknesses of the active material of the second electrode 700, the diaphragm 200, and the second active layer 130 is equal to the extension length of the seal 400.

[0153] The second electrode 700 includes a second current collector 710 and a fourth active layer 720, with the active material of the second electrode 700 forming the fourth active layer 720. By setting the sum of the thicknesses of the fourth active layer 720, the separator 200, and the second active layer 130 to be equal to the extension length of the seal 400, it can be ensured that the seal 400 completely covers the sides of the cell body during assembly, preventing any potential leakage paths. This matching design helps maintain the structural integrity of the bipolar battery during operation, preventing seal failure due to thermal expansion or mechanical stress.

[0154] In other embodiments, the sum of the thicknesses of the first active layer of one of two adjacent bipolar electrodes 100, the second active layer of the other, and the separator 200 is equal to the extension length of the seal 400. By setting the sum of the thicknesses of the first active layer 120, the separator 200, and the second active layer 130 in adjacent bipolar electrodes 100 to be equal to the extension length of the seal 400, it can be ensured that the seal 400 completely covers the sides of the cell body during assembly, preventing any potential leakage paths. This matching design helps maintain the structural integrity of the bipolar battery during operation, preventing seal failure due to thermal expansion or mechanical stress.

[0155] In some embodiments, the extension length of the seal 400 ranges from 50 to 150 μm. The thickness of the diaphragm 200 ranges from 6 to 50 μm.

[0156] As one possible implementation, the seal 400 includes a tab-like adhesive and / or a metal adhesive.

[0157] For example, a type of adhesive called a polar adhesive is elastic and chemically resistant. Polar adhesives effectively fill gaps, providing a reliable seal. The elasticity of polar adhesives helps absorb deformation caused by thermal expansion or mechanical stress, maintaining seal integrity.

[0158] Metallic adhesive is an adhesive containing metal particles. Using metallic adhesive in seal 400 can improve the mechanical strength and conductivity of the sealed area. The use of metallic adhesive helps ensure the structural stability of the bipolar battery and prevents seal failure due to external stress.

[0159] In some embodiments, the seal 400 may be a type of tab adhesive.

[0160] In other embodiments, the seal 400 may be a metal adhesive.

[0161] In some other embodiments, the seal 400 may be a type of tab adhesive or a metal adhesive.

[0162] For example, in the process of fabricating a bipolar battery, referring to Figure 3 As shown, firstly, the diaphragm 200 is immersed in the electrolyte 300; then, the diaphragm 200 immersed in the electrolyte 300 is placed on the corresponding electrode; subsequently, another electrode is placed on the diaphragm 200; finally, the electrode is sealed by the sealing element 400.

[0163] Secondly, embodiments of this application provide an electrical device including a bipolar battery.

[0164] For example, the electrical equipment can be a vehicle, a mobile phone, a drone, a portable ultrasound device, etc. This application does not limit the type of electrical equipment.

[0165] It is understood that since the electrical equipment of this application adopts the technical solution of the above-described bipolar battery embodiment, it has at least the beneficial effects brought about by the technical solution of the above-described embodiment, which will not be elaborated here.

[0166] The technical solution of the bipolar battery of this application will be further described below with reference to specific embodiments.

[0167] Example 1: A boehmite-coated membrane body was coated onto the surface of a polypropylene membrane substrate. The boehmite-coated membrane substrate was then immersed in electrolyte 300. Electrolyte 300 comprised LiPF6, ethylene carbonate EC, and ethylene methyl carbonate EMC. In electrolyte 300, the concentration of LiPF6 was 1 mol / L, and the volume ratio of ethylene carbonate to ethylene methyl carbonate was 3:7. The membrane 200 was 10 cm long and 10 cm wide.

[0168] Example 2: A polyacrylonitrile membrane body prepared by electrospinning was immersed in electrolyte 300. Electrolyte 300 included LiPF6, ethylene carbonate EC, and ethylene methyl carbonate EMC. In electrolyte 300, the concentration of LiPF6 was 1 mol / L, and the volume ratio of ethylene carbonate to ethylene methyl carbonate was 3:7. The membrane 200 was 10 cm long and 10 cm wide.

[0169] Example 3: A polypropylene membrane body was melted, and hydrophilic silica particles were added to the membrane body. After the membrane body with added hydrophilic silica particles solidified, the composite membrane body was immersed in electrolyte 300. Electrolyte 300 includes LiPF6, ethylene carbonate EC, and ethylene methyl carbonate EMC. In electrolyte 300, the concentration of LiPF6 is 1 mol / L, and the volume ratio of ethylene carbonate to ethylene methyl carbonate is 3:7. The membrane 200 has a length of 10 cm and a width of 10 cm.

[0170] Comparative Example 1: A polypropylene membrane body was immersed in electrolyte 300. Electrolyte 300 included LiPF6, ethylene carbonate EC, and ethylene methyl carbonate EMC. In electrolyte 300, the concentration of LiPF6 was 1 mol / L, and the volume ratio of ethylene carbonate to ethylene methyl carbonate was 3:7. The membrane 200 was 10 cm long and 10 cm wide.

[0171] Test example: Weigh the mass of the diaphragm 200 before it is soaked in the electrolyte 300 using a balance, and record it as the first mass.

[0172] After the diaphragm 200 is immersed in electrolyte 300 for 30 seconds, the diaphragm 200 is taken out and its mass is weighed using a balance and recorded as the second mass.

[0173] 120 seconds after removing diaphragm 200, weigh diaphragm 200 using a balance and record the mass as the third mass.

[0174] Liquid absorption rate % = (second weight - first weight) / first weight × 100%.

[0175] Liquid retention rate % = (Third weight - First weight) / (Second weight - First weight) × 100%.

[0176] Table 1. Relevant mass, liquid absorption rate, and liquid retention rate in the examples and comparative examples.

[0177]

[0178] As can be seen from the examples and comparative examples, the liquid absorption rate in the examples is greater than 100%, and the liquid retention rate is greater than 60%. The liquid absorption rate and liquid retention rate of the examples are higher than those of the comparative examples.

[0179] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0180] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A bipolar battery, characterized in that, include: The battery cell body includes a plurality of stacked electrodes, with a separator (200) disposed between adjacent electrodes; The diaphragm (200) has a liquid absorption rate of more than 100% and a liquid retention rate of more than 60%.

2. The bipolar battery according to claim 1, characterized in that, The diaphragm (200) has a liquid storage section and / or a liquid-loving section.

3. The bipolar battery according to claim 2, characterized in that, The diaphragm (200) includes a diaphragm body having a porous structure that forms the liquid storage section.

4. The bipolar battery according to claim 3, characterized in that, The diaphragm (200) also includes a dopant, and the diaphragm body and the dopant form a composite.

5. The bipolar battery according to claim 4, characterized in that, The dopant material includes inorganic particles, metal-organic frameworks, or cellulose.

6. The bipolar battery according to claim 4, characterized in that, The dopant has hydrophilic functional groups, and the hydrophilic functional groups form the lyophilic portion; And / or, the membrane body has hydrophilic functional groups, which form the hydrophilic portion.

7. The bipolar battery according to claim 6, characterized in that, The hydrophilic functional group includes hydroxyl or carboxyl groups.

8. The bipolar battery according to claim 2, characterized in that, The diaphragm (200) includes a diaphragm body and a coating layer, wherein the coating layer is disposed on both sides of the diaphragm body in the thickness direction; The diaphragm body forms the liquid storage section; The coating layer forms the liquid reservoir and / or the hydrophilic portion.

9. The bipolar battery according to any one of claims 3-8, characterized in that, The material of the liquid storage section includes polypropylene, polyethylene, or polyimide.

10. The bipolar battery according to claim 5, characterized in that, The inorganic particles include boehmite or silica; And / or, the metal-organic framework includes a zeolite imidazole framework.

11. The bipolar battery according to any one of claims 1-8, characterized in that, The plurality of electrodes includes a first electrode (600), at least one bipolar electrode (100), and a second electrode (700).

12. The bipolar battery according to claim 11, characterized in that, The bipolar electrode (100) includes a current collector (110), a first active layer (120), and a second active layer (130); the first active layer (120) and the second active layer (130) are respectively disposed on both sides of the current collector (110) in the thickness direction; the first active layer (120) and the second active layer (130) have different polarities; The first active layer (120) is provided with the diaphragm (200) on the side opposite to the current collector (110), and / or the second active layer (130) is provided with the diaphragm (200) on the side opposite to the current collector (110).

13. The bipolar battery according to claim 12, characterized in that, The first electrode (600) and the first active layer (120) are disposed opposite to each other; the second electrode (700) and the second active layer (130) are disposed opposite to each other; Furthermore, a diaphragm (200) is disposed between the first electrode (600) and the first active layer (120); a diaphragm (200) is disposed between the second electrode (700) and the second active layer (130).

14. The bipolar battery according to claim 13, characterized in that, The bipolar battery also includes a seal (400) connected to the adjacent electrode and located on the outer periphery of the electrode and the separator (200).

15. The bipolar battery according to claim 14, characterized in that, The sealing element (400) is disposed at the edge of one of the two adjacent electrodes and is sealed to the other of the two adjacent electrodes.

16. The bipolar battery according to claim 14, characterized in that, The sealing element (400) includes a first sealing element (410) and a second sealing element (420). The first sealing element (410) is disposed at a portion of the edge of one of the two adjacent electrode pieces, and the second sealing element (420) is disposed at a portion of the edge of the other of the two adjacent electrode pieces. The first sealing element (410) and the second sealing element (420) are joined together to surround the outer periphery of the two adjacent electrode pieces.

17. The bipolar battery according to claim 14, characterized in that, Along the thickness direction of the diaphragm (200), the sum of the thicknesses of the active material of the first electrode (600), the diaphragm (200), and the first active layer (120) is equal to the extension length of the seal (400). And / or, the sum of the thicknesses of the active material of the second electrode (700), the diaphragm (200), and the second active layer (130) is equal to the extension length of the seal (400); And / or, the sum of the thicknesses of the first active layer (120) of one of the two adjacent bipolar electrodes (100), the second active layer (130) of the other of the two adjacent bipolar electrodes (100), and the diaphragm (200) is equal to the extension length of the seal (400).

18. The bipolar battery according to claim 14, characterized in that, The seal (400) includes tab-like adhesive and / or metal adhesive.

19. An electrical appliance, characterized in that, The bipolar battery includes any one of claims 1-18.

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