Battery monomer, battery device and electric equipment

Abstract

The utility model provides a battery monomer, a battery device and electric equipment, the battery monomer comprises a shell, a plurality of electrode assemblies and a heat dissipation assembly, the plurality of electrode assemblies are accommodated in the shell; the heat dissipation assembly is clamped between the two adjacent electrode assemblies; the heat dissipation assembly comprises a heat dissipation fin and a phase change material, the heat dissipation fin is provided with a packaging cavity, and the phase change material is contained in the packaging cavity. Through the mode, the cooling fins have heat conduction performance and can quickly conduct heat generated by the electrode assembly to the phase change material, and the phase change material can transfer and temporarily store the heat, so that excessive temperature rise caused by heat accumulation of the heat in the battery single body is slowed down.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a battery cell, a battery device, and an electrical appliance. Background Technology

[0002] As batteries become more widely used and the functions of the products they are applied to increase, the requirements for battery reliability are also becoming more stringent. One source of battery unreliability is thermal runaway, which refers to a chain of exothermic reactions triggered inside the battery due to various reasons, causing the battery temperature to rise rapidly and potentially leading to fire or explosion. Utility Model Content

[0003] The main technical problem addressed by this application is to provide a battery cell, battery device, and electrical equipment with excellent heat dissipation capabilities.

[0004] To solve the above-mentioned technical problems, in a first aspect, this application adopts a technical solution that provides a single battery cell, comprising:

[0005] case;

[0006] Multiple electrode assemblies are housed within the housing;

[0007] A heat dissipation assembly is sandwiched between two adjacent electrode assemblies;

[0008] The heat dissipation component includes a heat sink and a phase change material. The heat sink has an encapsulation cavity, and the phase change material is housed within the encapsulation cavity.

[0009] In the above technical solution, by setting a heat dissipation component sandwiched between two adjacent electrode components, the distance between the heat dissipation component and the electrode components is short, resulting in a shorter heat conduction path and improved heat dissipation efficiency. The heat dissipation component includes a heat sink and a phase change material. The heat sink has thermal conductivity, which can quickly conduct the heat generated by the electrode components to the phase change material. The phase change material can also transfer and temporarily store heat according to sensible heat (specific heat capacity) or latent heat (phase change heat). Then, the heat is transferred to the outside of the battery cell through the heat sink. In this process, the phase change material can play a role in thermal buffering. Even under high current, when the heat generation rate is greater than the heat dissipation rate, the heat generated by the electrode components can be quickly transferred to the phase change material. The heat accumulation site is also transferred from the electrode components to the heat dissipation component, which alleviates the problem of excessive temperature rise caused by heat accumulation in the electrode components.

[0010] In some embodiments, the outer surface of the current collector of the outermost layer of the electrode assembly includes a smooth region.

[0011] In the above technical solution, by setting the outer surface of the outermost current collector of the electrode assembly to include a smooth area, which is the area without an active material layer, the heat generated by the electrode assembly can be quickly transferred to the heat dissipation assembly through the smooth area, reducing the influence of the low thermal conductivity active material on heat conduction, and enabling the internal heat of the electrode assembly to be quickly balanced. In addition, the smooth area can make the electrode assembly and the heat sink fit more tightly, improving the heat transfer efficiency.

[0012] In some embodiments, the electrode assembly is a wound structure, one ring of which includes a cathode electrode, a first diaphragm, an anode electrode, and a second diaphragm stacked from the inside out; the outer surface of the anode current collector of the outermost ring of the electrode assembly includes the smooth surface area, and the second diaphragm of the outermost ring covers the smooth surface area and is disposed in contact with the heat sink.

[0013] In the above technical solution, by setting the outer surface of the anode current collector of the outermost anode plate of the electrode assembly to include a smooth area, and the second separator of the outermost ring to cover the smooth area and be in contact with the heat sink, the heat transfer distance inside the battery cell can be shortened, adding a new way for heat to be transferred outward. The setting of the heat sink, phase change material and smooth area also increases the overall heat conduction and heat exchange capacity inside the battery cell.

[0014] In some embodiments, the electrode assembly has a flat structure, and the anode electrode has one more turn than the cathode electrode; the outermost anode electrode has its tail end located on the plane of the flat structure near the heat sink; the outer surface of the anode current collector of the outermost anode electrode from the tail end to the corner is the smooth surface area.

[0015] In the above technical solution, by setting the electrode assembly to a flat structure, the anode electrode is wound one more turn than the cathode electrode. The end of the outermost anode electrode is located on the plane of the flat structure near the heat sink. The outer surface of the anode current collector of the outermost anode electrode from the end to the corner is a smooth area. In this way, the smooth area of ​​the anode current collector from the end to the corner can be in contact with the heat sink, increasing the heat conduction area. This allows the heat inside the electrode assembly to be quickly conducted to the heat sink through the anode current collector, thereby slowing down the temperature rise rate inside the battery cell. At the same time, it reduces the impact of adding the heat sink inside the battery cell on the overall thickness of the battery cell.

[0016] In some embodiments, the heat sink includes a package portion and a first connecting portion, the package portion having the package cavity, one end of the first connecting portion being connected to the package portion, and the other end being connected to the tab of the electrode assembly.

[0017] In the above technical solution, the temperature difference at different locations of the battery cell is large, especially the temperature rise is large at the electrode tabs on the inner side of the electrode assembly. By setting a heat sink including a packaging part and a first connecting part, the packaging part has a packaging cavity, one end of the first connecting part is connected to the packaging part, and the other end is connected to the electrode tabs of the electrode assembly. In this way, the heat at the electrode tabs of the electrode assembly with large temperature rise can be quickly conducted to the phase change material, which can improve the temperature uniformity at different locations of the battery cell.

[0018] In some embodiments, the encapsulation portion includes an edge-connected first encapsulation layer and a second encapsulation layer, with the encapsulation cavity formed between the first encapsulation layer and the second encapsulation layer.

[0019] In the above technical solution, by including a first encapsulation layer and a second encapsulation layer connected at the edge of the encapsulation part, and forming an encapsulation cavity between the first encapsulation layer and the second encapsulation layer, such a design allows the corresponding encapsulation layer to be replaced when the encapsulation part is partially damaged or aged, which is beneficial for maintenance and replacement.

[0020] In some embodiments, the first connecting portion includes:

[0021] The first connecting layer has one end connected to the edge of the first encapsulation layer and the other end in contact with the first tab of the electrode assembly;

[0022] The second connecting layer has one end connected to the edge of the second encapsulation layer and the other end in contact with the first tab of the electrode assembly.

[0023] In the above technical solution, by setting the first connecting part to include a first connecting layer and a second connecting layer, and the first connecting layer is connected to the first encapsulation layer and the electrode assembly, and the second connecting layer is connected to the second encapsulation layer and the electrode assembly, the first connecting layer and the first encapsulation layer and the second connecting layer connected thereto can provide multiple heat conduction paths. The first connecting layer and the second connecting layer can also be selected with different thermal conductive materials as needed to provide multiple functions, such as taking into account heat transfer efficiency, hardness, toughness, etc. In addition, if the thermal conduction performance of one decreases, the other can still continue to work.

[0024] In some embodiments, the first connecting layer and the second connecting layer are stacked and contacted with the first tab of the same electrode assembly.

[0025] In the above technical solution, by setting the first connecting layer and the second connecting layer to be stacked and in contact with the first tab of the same electrode assembly, the first connecting layer and the second connecting layer can quickly conduct the heat at the first tab of the electrode assembly with a large temperature rise to the phase change material. The efficient heat conduction helps to maintain the first tab of the electrode assembly within a suitable operating temperature range.

[0026] In some embodiments, the first connecting layer is in contact with a first tab of one of the two adjacent electrode assemblies;

[0027] The second connecting layer is in contact with the first tab of another electrode assembly of the two adjacent electrode assemblies.

[0028] In the above technical solution, by setting the first connecting layer to contact the first tab of one of the two adjacent electrode components, and the second connecting layer to contact the first tab of the other of the two adjacent electrode components, the heat dissipation of the two electrode components can be taken into account, thereby improving the reliability and stability of the entire battery cell.

[0029] In some embodiments, the first encapsulation layer, the second encapsulation layer, and the first connector are integrally formed.

[0030] In the above technical solution, the one-piece molding design can reduce the connection points between the first encapsulation layer, the second encapsulation layer and the first connecting part, and the connection parts are less likely to loosen, which is conducive to improving the overall mechanical strength, and can better control the size of the encapsulation part and reduce the production process.

[0031] In some embodiments, the width of the encapsulation portion is greater than the width of the first connecting portion.

[0032] In the above technical solution, by setting the width of the encapsulation part to be greater than the width of the first connection part, on the one hand, the encapsulation part with a larger width can provide a larger heat dissipation area, and on the other hand, the first connection part with a smaller width reduces the risk of the two tabs of different polarities being short-circuited by the first connection part.

[0033] In some embodiments, the heat sink includes:

[0034] The packaging section has the packaging cavity.

[0035] First connecting part; one end of the first connecting part is connected to the encapsulation part, and the other end is in contact with the first tab of the electrode assembly;

[0036] Second connecting part; one end of the second connecting part is connected to the encapsulation part, and the other end is in contact with the second tab of the electrode assembly;

[0037] At least one of the first connecting part and the second connecting part is an insulating structural component.

[0038] In the above technical solution, there is a large temperature difference at different locations within the battery cell, especially at the tabs near the electrode assembly on the inner side. By incorporating a heat sink including an encapsulation portion, a first connecting portion, and a second connecting portion, heat from the first and second tabs, which experience significant temperature rise, can be rapidly conducted away, improving heat dissipation efficiency and thus enhancing the temperature uniformity across different locations within the battery cell. Furthermore, at least one of the first and second connecting portions is an insulating structure, reducing the risk of short circuits between the first and second tabs caused by the heat sink.

[0039] In some embodiments, the battery cell further includes a cover plate assembly; the heat sink includes an encapsulation portion and a first connecting portion, the encapsulation portion having the encapsulation cavity, one end of the first connecting portion being connected to the encapsulation portion, and the other end being connected to the cover plate assembly.

[0040] In the above technical solution, by setting the battery cell to include a cover plate assembly, the heat sink to include an encapsulation part and a first connection part, the encapsulation part has an encapsulation cavity, one end of the first connection part is connected to the encapsulation part and the other end is connected to the cover plate assembly, the heat of the first connection part can be conducted away through the cover plate assembly, thereby reducing the temperature of the battery cell.

[0041] In some embodiments, the cover plate assembly includes a cover plate, a pole, and an adapter plate; the cover plate, the pole, or the adapter plate is in contact with the other end of the first connecting portion.

[0042] In the above technical solutions, the area of ​​the cover plate, pole post or adapter piece in the embodiments is usually large and directly connected to the battery casing or structural components. By setting the cover plate assembly including the cover plate, pole post and adapter piece, and the cover plate, pole post or adapter piece contacting and connecting with the other end of the first connecting part, the heat dissipation efficiency can be improved.

[0043] In some embodiments, the first end of the electrode assembly is provided with a tab, and the second end is not provided with a tab, and the second end is disposed opposite to the first end; the heat dissipation assembly is disposed near the first end of the electrode assembly and spaced apart from the second end near the electrode assembly.

[0044] In the above technical solution, by placing the heat dissipation component at the first end, the heat conduction path from the electrode to the heat dissipation component can be reduced, the heat dissipation efficiency can be improved, and the heat accumulation at the electrode where heat is absorbed faster can be reduced, which is conducive to a more balanced heat distribution inside the battery cell.

[0045] In some embodiments, the first end is the top end and the second end is the bottom end; the direction from the top end to the bottom end is the height direction, and the ratio of the height of the heat dissipation component to the height of the electrode component is 50%-70%.

[0046] In the above technical solution, by setting the first end as the top and the second end as the bottom, and the direction from the top to the bottom as the height direction, the ratio of the height of the heat dissipation component to the height of the electrode component is 50%-70%, which can ensure that there is sufficient contact area between the heat dissipation component 30 and the electrode component 20, so as to achieve effective heat dissipation efficiency without increasing the weight of the battery cell 1, which is conducive to the lightweighting of the battery cell.

[0047] In some embodiments, the heat sink comprises at least two layers of metal foil; the phase change material comprises an organic phase change material, an inorganic phase change material, or a eutectic material.

[0048] In the above technical solution, the heat sink includes at least two layers of metal foil. The metal foil has good thermal conductivity. Due to its thin and uniform characteristics, the metal foil can quickly conduct heat away from the heat source, effectively improving heat dissipation efficiency and contributing to the lightweighting of the battery. The metal foil is easy to cut and shape to adapt to different space constraints. In addition, different phase change materials have different advantages, which can be selected according to actual needs during design. Among them, organic phase change materials have the advantages of stable physicochemical properties, good formability, low toxicity, low cost, and large latent heat of phase change. Inorganic phase change materials have the advantages of a wide applicable temperature range, can be used in various temperature environments, have a high phase change enthalpy, can efficiently store energy and transfer heat, have good thermal stability, can work stably for a long time under harsh conditions such as high temperature, and have strong thermal conductivity and fast heat transfer speed. Eutectic materials have an excellent balance in terms of thermal performance, chemical stability, and mechanical properties, and are highly adjustable. Parameters such as phase change temperature and latent heat can be customized according to needs. They have low supercooling, are easier to release heat during cooling, have less phase separation, and improve performance stability during cycle use.

[0049] To solve the above-mentioned technical problems, in a second aspect, another technical solution adopted by this application is to provide a battery device, including a battery housing and a battery cell provided in any of the above embodiments, wherein the battery cell is installed in the battery housing.

[0050] In the above embodiments, by setting a heat dissipation component sandwiched between two adjacent electrode components, the distance between the heat dissipation component and the electrode components is short, resulting in a shorter heat conduction path and improved heat dissipation efficiency. The heat dissipation component includes a heat sink and a phase change material. The heat sink has thermal conductivity, which can quickly conduct the heat generated by the electrode components to the phase change material. The phase change material can also transfer and temporarily store heat according to sensible heat (specific heat capacity) or latent heat (phase change heat). Then, the heat is transferred to the outside of the battery cell through the heat sink. In this process, the phase change material can play a role in thermal buffering. Even under high current, when the heat generation rate is greater than the heat dissipation rate, the heat generated by the electrode components can be quickly transferred to the phase change material. The heat accumulation site is also transferred from the electrode components to the heat dissipation component, which alleviates the problem of excessive temperature rise caused by heat accumulation in the electrode components.

[0051] To solve the above-mentioned technical problems, in a third aspect, another technical solution adopted by this application is to provide an electrical device, including an electrical component and a battery device provided in the second aspect, wherein the battery device is electrically connected to the electrical component.

[0052] In the above embodiments, by setting a heat dissipation component sandwiched between two adjacent electrode components, the distance between the heat dissipation component and the electrode components is short, resulting in a shorter heat conduction path and improved heat dissipation efficiency. The heat dissipation component includes a heat sink and a phase change material. The heat sink has thermal conductivity, which can quickly conduct the heat generated by the electrode components to the phase change material. The phase change material can also transfer and temporarily store heat according to sensible heat (specific heat capacity) or latent heat (phase change heat). Then, the heat is transferred to the outside of the battery cell through the heat sink. In this process, the phase change material can play a role in thermal buffering. Even under high current, when the heat generation rate is greater than the heat dissipation rate, the heat generated by the electrode components can be quickly transferred to the phase change material. The heat accumulation site is also transferred from the electrode components to the heat dissipation component, which alleviates the problem of excessive temperature rise caused by heat accumulation in the electrode components. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 Exploded views of a single battery cell provided in some embodiments of this application;

[0055] Figure 2 A side view of an electrode assembly and a heat dissipation assembly provided in some embodiments of this application;

[0056] Figure 3 for Figure 2 Top view;

[0057] Figure 4 for Figure 2 Sectional view along line III-III;

[0058] Figure 5 Electrode assemblies with wound structures provided in some embodiments of this application;

[0059] Figure 6 Electrode assemblies with folded structures provided in other embodiments of this application;

[0060] Figure 7 This is a schematic diagram of the structure of a heat dissipation assembly provided in some embodiments of this application;

[0061] Figure 8 for Figure 7 Side view;

[0062] Figure 9 for Figure 7 A cross-sectional view of line IX-IX;

[0063] Figure 10 for Figure 7 A sectional view along line XX;

[0064] Figure 11 Schematic diagrams of the electrode assembly and heat dissipation assembly provided in other embodiments of this application;

[0065] Figure 12 Schematic diagrams of the electrode assembly and heat dissipation assembly provided in some embodiments of this application;

[0066] Figure 13 This is a schematic diagram of the structure of a heat dissipation assembly provided in some embodiments of this application;

[0067] Figure 14 for Figure 13 A schematic diagram of a heat dissipation component sandwiched between two adjacent electrode components;

[0068] Figure 15 This is a schematic diagram of the structure of the electrode assembly, heat dissipation assembly, and cover plate assembly provided in some embodiments of this application;

[0069] Figure 16 for Figure 15 Side view of the electrode assembly and heat dissipation assembly;

[0070] Figure 17 for Figure 15 Top view;

[0071] Figure 18 for Figure 16A sectional view along XVIII-XVIII;

[0072] Figure 19 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0073] Figure 20 This is a schematic diagram of the structure of the electrical equipment provided in the embodiments of this application.

[0074] Explanation of icon numbers:

[0075] 1-Battery cell, 10-Casing, 20-Electrode assembly, 21-Anode electrode, 210-Smooth surface area, 22-Cathode electrode, 23-First separator, 24-Second separator, 25-Taper, 251-First tab, 252-Second tab, 201-First part, 202-Second part, 40-Cover assembly, 41-Cover, 42-Terminal post, 43-Adapter, 30-Heat dissipation assembly, 31-Heat dissipation fin, 310-Encapsulation part, 311-First encapsulation layer, 312-Second encapsulation layer, 330-First connection part, 331-First connection layer, 332-Second connection layer, 350-Second connection part, 32-Phase change material, 100-Battery assembly, 2-Battery housing, 201-First part, 202-Second part, 1000-Vehicle, 200-Electrical device. Detailed Implementation

[0076] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0077] 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 be limiting of this 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. For example, a process, method, system, product, or apparatus that comprises a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus.

[0078] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0079] In the description of the embodiments of this application, the technical terms "first," "second," "third," etc., are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more (including two), such as two, three, etc., unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0080] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0081] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the relative orientation or positional relationship between the components in a certain posture (as shown in the accompanying drawings) as shown in the drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0082] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0083] As batteries become more widely used and the functions of the products they are applied to increase, the requirements for battery reliability are also becoming more stringent. One source of battery unreliability is thermal runaway, which refers to a chain of exothermic reactions triggered inside the battery due to various reasons, causing the battery temperature to rise rapidly and potentially leading to fire or explosion.

[0084] Furthermore, in the field of new energy, lithium-ion batteries have become one of the key areas of high-tech development due to their advantages such as high voltage, high capacity, low consumption, no memory effect, no pollution, small size, low internal resistance, low self-discharge, and high cycle life.

[0085] For lithium-ion batteries, there is a large temperature difference in different parts of the battery cell, especially the temperature rise is large on the inner side of the electrode assembly (bare cell) near the tab, which can easily cause local lithium plating problems.

[0086] On the one hand, the heat generated at the top inner side of the electrode assembly (bare cell) must be conducted to the sidewall of the outer casing (e.g., aluminum casing), resulting in a long heat conduction path and potential heat accumulation. On the other hand, near the tab, the narrower tab width (compared to the current collector) increases resistance and current density, leading to increased heat generation and a temperature rise. Furthermore, the temperature rise is beneficial for enhancing the activity of the electrochemical reaction, and its effect on the lithium plating reaction is greater than that on the lithium intercalation reaction; therefore, localized lithium plating can be observed in the high-temperature region at the top inner side.

[0087] To address one or more of the aforementioned problems, embodiments of this application provide a battery cell, which includes a housing, multiple electrode assemblies, and a heat dissipation assembly. The multiple electrode assemblies are housed within the housing; the heat dissipation assembly is sandwiched between two adjacent electrode assemblies; the heat dissipation assembly includes a heat sink and a phase change material, the heat sink having an encapsulation cavity, and the phase change material being housed within the encapsulation cavity.

[0088] In this embodiment, a heat dissipation component is sandwiched between two adjacent electrode components, resulting in a shorter heat conduction path and improved heat dissipation efficiency. The heat dissipation component includes a heat sink and a phase change material. The heat sink has thermal conductivity, which can quickly conduct the heat generated by the electrode components to the phase change material. The phase change material can also transfer and temporarily store heat based on sensible heat (specific heat capacity) or latent heat (phase change heat). The heat is then transferred to the outside of the battery cell through the heat sink. In this process, the phase change material can act as a thermal buffer. Even at high current rates, where the heat generation rate is greater than the heat dissipation rate, the heat generated by the electrode components can be quickly transferred to the phase change material. The heat accumulation site is also shifted from the electrode components to the heat dissipation component, alleviating the problem of excessive temperature rise caused by heat accumulation in the electrode components.

[0089] The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0090] Please see Figures 1-4 ,in, Figure 1 Exploded views of battery cell 1 provided in some embodiments of this application; Figure 2 Side view of electrode assembly 20 and heat dissipation assembly 30 provided in some embodiments of this application; Figure 3 for Figure 2 Top view; Figure 4 for Figure 2 Sectional view along line III.

[0091] Battery cell 1 refers to the smallest unit that makes up a battery. Battery cell 1 can include lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, etc. Battery cells can be cylindrical, flat, or other shapes. Battery cells 1 are generally divided into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells. For ease of explanation, the following embodiments use lithium-ion batteries as an example.

[0092] The battery cell 1 provided in this application includes a housing 10, multiple electrode assemblies 20, and a heat dissipation assembly 30. The multiple electrode assemblies 20 are housed within the housing 10, and the heat dissipation assembly 30 is sandwiched between two adjacent electrode assemblies 20. The heat dissipation assembly 30 includes a heat sink 31 and a phase change material 32. The heat sink 31 has an encapsulation cavity, and the phase change material 32 is housed within the encapsulation cavity. The number of electrode assemblies 20 and heat dissipation assembly 30 can be set as needed. This application uses an example of a housing 10 housing two electrode assemblies 20 and one heat dissipation assembly 30 for illustration.

[0093] In some embodiments, the housing 10 refers to the component that encloses the electrode assembly 20 to form the internal environment of the battery cell 1. This internal environment can accommodate components such as the electrode assembly 20, the heat dissipation component 30, and the electrolyte, providing protection for the components housed within it and reducing the risk of external contamination. The housing 10 can have various shapes and sizes, such as cuboid, cylindrical, or hexagonal prism. Specifically, the shape of the housing 10 can be determined based on the specific shape and size of the electrode assembly 20. The housing 10 can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0094] Electrode assembly 20 is the component in cell 1 where the electrochemical reaction takes place. Please refer to [other sources]. Figure 5 and Figure 6The electrode assembly 20 is mainly formed by winding or folding an anode electrode 21 and a cathode electrode 22, and a separator is usually provided between the anode electrode 21 and the cathode electrode 22. In this embodiment, the separator can be a diaphragm. The diaphragm can be made of polypropylene (PP) or polyethylene (PE), etc. The anode electrode 21 can also be called the negative electrode, and the cathode electrode 22 can also be called the positive electrode. During the charging and discharging process of the battery cell 1, active ions (e.g., lithium ions) are inserted and extracted back and forth between the anode electrode 21 and the cathode electrode 22.

[0095] In some embodiments, please continue to see Figures 1-4 The electrode assembly 20 also includes tabs 25, which can be connected to electrodes of the same electrical polarity as those of the electrode assembly 20. For example, tabs 25 may include an anode tab and a cathode tab, with the anode electrode of the electrode assembly 20 connected to the anode tab and the cathode electrode of the electrode assembly 20 connected to the cathode tab.

[0096] The anode electrode 21 includes an anode current collector and an anode active material layer, the anode active material layer being coated on the surface of the anode current collector. The cathode electrode 22 includes a cathode current collector and a cathode active material layer, the cathode active material layer being coated on the surface of the cathode current collector. In some embodiments of this application, in the lithium-ion battery, the cathode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.; the anode current collector material can be copper, and the anode active material can be carbon or silicon, etc.

[0097] Some embodiments of this application provide a method for preparing an electrode assembly 20, which is illustrated using a lithium-ion battery as an example.

[0098] Cathode electrode 22: Prepare cathode active material layer slurry by adding cathode active material (powder containing lithium iron phosphate active material), positive electrode conductive agent (conductive carbon black) and binder (PVDF) to solvent (N-methylpyrrolidone). The cathode active material accounts for 95%-98% by weight, the positive electrode conductive agent and binder account for 0.2%-2% by weight, and the solid content of the solvent is 60%-70%. Coat both sides of the cathode current collector with cathode active material layer slurry, the thickness of the cathode current collector is 10μm-15μm. Cold press and dry the cathode current collector coated with cathode active material layer slurry. Roll press and slit the dried cathode active material layer.

[0099] Anode electrode 21: Prepare an anode active material layer slurry by adding graphite, conductive agent, binder, and dispersant to a solvent (N-methylpyrrolidone). The weight ratios of graphite, conductive agent, binder, and dispersant are 96%, 1%, 2%, and 1%, respectively, and the solid content of the solvent is 70%. Coat both sides of the anode current collector with the anode active material layer slurry. The anode current collector is a copper foil with a thickness of 6 μm. The thickness of the active material layer (before rolling) is approximately 100 μm. The anode current collector coated with the anode active material layer slurry is subjected to cold pressing and drying. The dried anode active material layer is rolled and slit. The rolling pressure is 60T-100T, and the speed is 20m / min-100m / min. The thickness of the anode active material layer after rolling is approximately 60 μm.

[0100] Separator: PE or PP material or composite diaphragm is provided, with a thickness of 4μm-15μm.

[0101] Electrolyte: It is made by dissolving lithium salt in a solvent, with a lithium salt molar concentration of 0.8 mol / L to 1.2 mol / L. The solvent is one or more of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC).

[0102] Assembly: The anode electrode 21, the diaphragm and the cathode electrode 22 are laminated by rolling. The laminated anode electrode 21, the diaphragm and the cathode electrode 22 are then wound or folded to form a core (electrode assembly 20).

[0103] Furthermore, after assembling the electrode assembly 20, the heat dissipation assembly 30, and the housing 10, an electrolyte is injected, and a battery cell 1 is formed through formation.

[0104] Please see also Figures 7-10 , Figure 7 This is a schematic diagram of the structure of the heat dissipation assembly 30 provided in some embodiments of this application; Figure 8 for Figure 7 Side view; Figure 9 for Figure 7 A cross-sectional view of line IX-IX; Figure 10 for Figure 7 A cross-sectional view along line XX.

[0105] The heat dissipation component 30 is used to control the temperature of the battery cell 1 to maintain a stable temperature as much as possible. The heat sink 31 is typically a sheet-like structure made of a material with high thermal conductivity. The sheet-like structure has a large area, thus providing a large contact area with the electrode assembly 20, allowing for faster heat transfer from the electrode assembly 20 to the phase change material 32. Specifically, when the temperature of the electrode assembly 20 rises, heat is conducted from the surface of the electrode assembly 20 to the heat sink 31. The large area of ​​the heat sink 31 enables faster heat transfer to the phase change material 32. The heat sink 31 can be made of metallic materials, such as aluminum, aluminum alloys, copper, copper alloys, or silver; or carbon materials, such as graphite, graphene, carbon nanotubes, or carbon fiber composites. In some embodiments, the shape of the heat sink 31 can be specifically designed based on measured and simulated temperature curves inside the battery cell 1 to minimize the volume and weight of the heat sink 31 while meeting heat dissipation requirements. This application uses copper foil as the heat sink 31 for illustration.

[0106] Phase change material 32 is a special energy storage material that can undergo physical phase changes at specific temperatures, such as changing from solid to liquid, from liquid to gas, or vice versa. During this process, it absorbs or releases a large amount of heat energy. When the temperature of the battery cell 1 rises to the phase change temperature of the phase change material 32, the phase change material 32 changes from solid to liquid. This process is endothermic, absorbing a large amount of heat generated by the battery, thus effectively reducing the temperature of the battery cell 1. Conversely, when the temperature of the battery cell 1 decreases, the liquid phase change material 32 re-solidifies, releasing the previously absorbed heat, thus playing a role in temperature regulation and insulation.

[0107] In this embodiment, the heat sink 31 is sandwiched between two electrode components 20. The heat dissipation component 30 includes the heat sink 31 and the phase change material 32. The phase change material 32 is disposed in the encapsulation cavity of the heat sink 31. The heat sink 31 has thermal conductivity and can quickly conduct the heat generated by the electrode components 20 to the phase change material 32. The phase change material 32 can also transfer and temporarily store heat according to sensible heat (specific heat capacity) or latent heat (phase change heat). Then, the heat is transferred to the outside of the battery cell 1 through the heat sink 31. In this process, the phase change material 32 can play a role in heat buffering. Even under high current, the heat generation rate is greater than the heat dissipation rate. The heat generated in the battery cell 1 can be quickly transferred from the electrode components 20 to the phase change material 32. The heat accumulation position is also transferred from the electrode components 20 to the heat dissipation component 30, which reduces the excessive temperature rise caused by heat accumulation in the electrode components 20.

[0108] Furthermore, for lithium-ion batteries, excessive temperature rise can easily lead to lithium plating, which not only reduces the lifespan of individual battery cells but also seriously affects safety. Moreover, the lithium dendrites generated by lithium plating can pierce the separator, causing a short circuit between the positive and negative electrodes, leading to a series of safety issues such as overheating and fire. The technical solution provided in this application can also alleviate the problem of localized lithium plating caused by excessive temperature rise, thereby improving the cycle life of battery cell 1 and mitigating the problems of electrode breakage caused by increased thickness and expansion force due to lithium plating, and battery cell 1 failure caused by weld cracking in the casing 10.

[0109] Further, in some embodiments, the heat dissipation component 30 is prepared as follows: First, a copper foil with a thickness of 5μm-100μm is provided; then, according to the area and heat distribution data of the electrode component 20, two copper foils are die-cut into the required shape and area, the shape being similar to the electrode sheet and retaining a connection portion on one side; next, the edges of the copper foil are welded, and a micro-hole is left for injecting phase change material 32. The amount of phase change material 32 can be 0.1g / cm2-10g / cm2, for example, it can be 0.1g / cm2, 0.5g / cm2, 1g / cm2, 2g / cm2, 3g / cm2, 4g / cm2, 5g / cm2, 6g / cm2, 7g / cm2, 8g / cm2, 9g / cm2 or 10g / cm2, etc.; further, the micro-hole is welded; finally, the edges of the copper foil are checked for burrs, and the welding is checked for incomplete soldering. In some embodiments, the same copper foil can be folded to form a double-layer copper foil, the unconnected edges can be welded, and a micro-hole can be left for injection.

[0110] In some embodiments, please also refer to Figure 5 and Figure 6 The outermost current collector surface of the electrode assembly 20 includes a smooth region 210. The smooth region 210 is the area without an active material layer; for example, the outer surface of the smooth region 210 may not be coated with an active material layer, while the inner surface may be coated with one. The smooth region 210 can be connected to the tab 25 and has good thermal conductivity. This allows the heat generated by the electrode assembly 20 to be quickly transferred to the heat dissipation assembly 30 through the smooth region 210, reducing the impact of the low thermal conductivity of the active material on heat conduction and enabling rapid heat equalization within the electrode assembly 20. Furthermore, the smooth region 210 allows for a tighter fit between the electrode assembly 20 and the heat sink 31, improving heat transfer efficiency.

[0111] Please continue reading Figure 5The electrode assembly 20 has a wound structure. One ring of the wound structure includes a cathode electrode 22, a first diaphragm 23, an anode electrode 21, and a second diaphragm 24 stacked from the inside out. The outer surface of the anode current collector of the outermost anode electrode 21 of the electrode assembly 20 includes a smooth area 210. The second diaphragm 24 of the outermost ring covers the smooth area 210 and is in contact with the heat sink 31.

[0112] The electrode assembly 20 is formed by stacking a cathode electrode 22, a first diaphragm 23, an anode electrode 21, and a second diaphragm 24, which can be wound clockwise or counterclockwise. The first diaphragm 23 serves to insulate and separate the cathode electrode 22 and the anode electrode 21, reducing the risk of short circuits between them while allowing active ions to pass through. The second diaphragm 24 serves to insulate and separate the anode electrode 21 from other components of the electrode assembly 20, reducing the risk of short circuits between the cathode electrode 22 and other conductive elements.

[0113] The outermost anode current collector of the outermost anode electrode 21 of the electrode assembly 20 includes a smooth area 210. The outermost second separator 24 covers the smooth area 210 and is arranged in contact with the heat sink 31. This can shorten the heat transfer distance inside the battery cell 1 and add a new way for heat to be transferred outward. The arrangement of the heat sink 31, the phase change material 32 and the smooth area 210 also increases the overall heat conduction and heat exchange capacity inside the battery cell 1.

[0114] Optionally, please see Figure 6 The stacked cathode electrode 22, first diaphragm 23, anode electrode 21 and second diaphragm 24 can be folded in a Z-shape or S-shape to form electrode assembly 20.

[0115] Furthermore, in some embodiments, the electrode assembly 20 has a flat structure, with the anode electrode 21 having one more turn than the cathode electrode 22; the outermost anode electrode 21's tail end is located on the plane of the flat structure near the heat sink 31; the outer surface of the anode current collector of the outermost anode electrode 21 from the tail end to the corner is a smooth area 210. In this way, the smooth area 210 of the anode current collector of the anode electrode 21 from the tail end to the corner can be attached to the heat sink 31, increasing the heat conduction area, so that the heat inside the electrode assembly 20 can be quickly conducted to the heat sink 31 through the anode current collector to slow down the temperature rise rate inside the battery cell 1, while reducing the impact of adding the heat sink 31 on the overall thickness of the battery cell 1.

[0116] Furthermore, because the area of ​​the tab 25 is narrower relative to the current collector, the resistance and current density increase, resulting in increased heat generation and a larger temperature rise at the tab 25 on the inner side of the electrode assembly 20 near the electrode assembly 20; therefore, in some embodiments, please refer to... Figure 3, Figure 4 , Figure 8 and Figure 10 The heat sink 31 includes an encapsulation portion 310 and a first connecting portion 330. The encapsulation portion 310 has an encapsulation cavity. One end of the first connecting portion 330 is connected to the encapsulation portion 310, and the other end is connected to the tab of the electrode assembly 20. Since the first connecting portion 330 of the heat sink 31 has good thermal conductivity, it can quickly conduct the heat from the tab 25 of the electrode assembly 20, which has a larger temperature rise, to the phase change material 32, thereby improving the temperature uniformity of different locations in the battery cell 1.

[0117] Optionally, in some embodiments, the encapsulation portion 310 may include a first encapsulation layer 311 and a second encapsulation layer 312 connected at their edges, with an encapsulation cavity formed between the first encapsulation layer 311 and the second encapsulation layer 312. The first encapsulation layer 311 and the second encapsulation layer 312 may be two copper foils or formed by folding the same copper foil. The first encapsulation layer 311 and the second encapsulation layer 312 may be made of the same material or different materials, with different materials having different thermal conductivity. For example, copper has a thermal conductivity of approximately 380 W / (m²). · K)-401W / (m · K)) is about 200 W / (m · K)-240W / (m · Copper has a high K) value, which allows it to quickly conduct heat generated by the electrode assembly 20. Copper also has strong corrosion resistance and high hardness, improving the stability of the heat sink 31. Aluminum, on the other hand, has low density, low cost, and good processing performance. The thermally conductive silicone sheet has good insulation properties and high resilience, effectively mitigating vibration and friction damage between the electrode assemblies 20 and reducing the risk of short circuits. Different combinations can fully utilize the performance advantages of different materials, thereby optimizing the efficiency of the entire heat dissipation process. Furthermore, this embodiment allows for the replacement of the corresponding encapsulation layer when part of the encapsulation section 310 is damaged or aged, facilitating repair and replacement.

[0118] Further, please see Figure 11 , Figure 11 This is a schematic diagram of the structure of the electrode assembly 20 and the heat dissipation assembly 30 provided in other embodiments of this application. The first connection portion 330 may include a first connection layer 331 and a second connection layer 332. One end of the first connection layer 331 is connected to the edge of the first encapsulation layer 311, and the other end is in contact with the first tab 251 of the electrode assembly 20. One end of the second connection layer 332 is connected to the edge of the second encapsulation layer 312, and the other end is in contact with the first tab 251 of the electrode assembly 20.

[0119] The shapes of the first connecting layer 331 and the second connecting layer 332 are not limited; they can be sheet-like or needle-like, with the sheet-like shape also being rectangular, trapezoidal, circular, elliptical, or teardrop-shaped. In some embodiments of this application, both the first connecting layer 331 and the second connecting layer 332 are rectangular sheets, which can increase the contact area with the first tab 251 and further improve heat dissipation efficiency. In addition, the first connecting layer 331 and the first encapsulation layer 311 and the second connecting layer 332 and the second encapsulation layer 312 connected thereto can provide multiple heat conduction paths. The first connecting layer 331 and the second connecting layer 332 can also be made of different thermally conductive materials as needed to provide multiple functions, such as balancing heat transfer efficiency, hardness, and toughness. Furthermore, even if the thermal conductivity of one layer decreases, the other can still continue to function.

[0120] In some embodiments, the first connecting layer 331 and the second connecting layer 332 are stacked and contacted with the first tab 251 of the same electrode assembly 20.

[0121] In this way, both the first connecting layer 331 and the second connecting layer 332 can quickly conduct the heat from the first tab 251 of the electrode assembly 20, which has a larger temperature rise, to the phase change material 32. The efficient heat conduction helps to maintain the first tab 251 of the electrode assembly 20 within a suitable operating temperature range.

[0122] Alternatively, in some other embodiments, please refer to Figure 12 , Figure 12 This is a schematic diagram of the structure of the electrode assembly 20 and the heat dissipation assembly 30 provided in some embodiments of this application. The first connecting layer 331 is in contact with the first tab 251 of one of the two adjacent electrode assemblies 20; the second connecting layer 332 is in contact with the first tab 251 of the other electrode assembly 20 of the two adjacent electrode assemblies 20.

[0123] This embodiment can take into account the heat dissipation of both electrode components 20, thereby improving the reliability and stability of the entire battery cell 1.

[0124] Optionally, in other embodiments, the first encapsulation layer 311, the second encapsulation layer 312, and the first connecting portion 330 are integrally formed. This integral design reduces the number of connection points between the first encapsulation layer 311, the second encapsulation layer 312, and the first connecting portion 330, making it less prone to loosening between the connections. This improves overall mechanical strength and allows for better control of the dimensions of the encapsulation portion 310, reducing production steps.

[0125] In some embodiments, please continue to see Figure 7The width of the package portion 310 is greater than the width of the first connecting portion 330. In this way, on the one hand, the wider package portion 310 can provide a larger heat dissipation area, and on the other hand, the narrower first connecting portion 330 reduces the risk of the two tabs 25 of different polarities being short-circuited by the first connecting portion 330.

[0126] Optionally, in some embodiments, please also refer to Figure 13 and Figure 14 , Figure 13 This is a schematic diagram of the structure of the heat dissipation assembly 30 provided in some embodiments of this application; Figure 14 for Figure 13 The diagram shows a heat dissipation component sandwiched between two adjacent electrode assemblies. The heat sink 31 includes an encapsulation portion 310, a first connecting portion 330, and a second connecting portion 350. The encapsulation portion 310 has an encapsulation cavity. One end of the first connecting portion 330 is connected to the encapsulation portion 310, and the other end is in contact with the first tab 251 of the electrode assembly 20. One end of the second connecting portion 350 is connected to the encapsulation portion 310, and the other end is in contact with the second tab 252 of the electrode assembly 20. At least one of the first connecting portion 330 and the second connecting portion 350 is an insulating structural component.

[0127] The first connecting portion 330 and the second connecting portion 350 may be similar in material and structure to the first connecting layer 331 and the second connecting layer 332 mentioned above. At least one of the first connecting portion 330 and the second connecting portion 350 is an insulating structural component, such as a thermally conductive silicone sheet or a thermally conductive ceramic insulating sheet.

[0128] The temperature difference between different locations in the battery cell 1 is relatively large, especially at the tabs 25 on the inner side of the electrode assembly 20, where the temperature rise is significant. By providing a heat sink 31 including a packaging portion 310, a first connecting portion 330, and a second connecting portion, the heat at the first tab 251 and the second tab 252, where the temperature rise is relatively large, can be quickly conducted away, improving heat dissipation efficiency and thus improving the temperature uniformity of different locations in the battery cell 1. In addition, at least one of the first connecting portion 330 and the second connecting portion is an insulating structure, which can reduce the risk of short circuit between the first tab 251 and the second tab 252 caused by the heat sink 31.

[0129] Optionally, in some embodiments, the battery cell 1 also includes other functional components, for example, please refer to Figures 15-18 The battery cell 1 includes a cover assembly 40. The heat sink 31 includes an encapsulation portion 310 and a first connecting portion 330. The encapsulation portion 310 has an encapsulation cavity. One end of the first connecting portion 330 is connected to the encapsulation portion 310, and the other end is connected to the cover assembly 40. The structure of the cover assembly 40 is as follows: Figure 1 As shown.

[0130] The cover assembly 40 is located on top of the electrode assembly 20 and serves several key functions, including sealing the interior of the battery cell 1, preventing electrolyte leakage, isolating the interior of the battery cell 1 from the external environment, and providing electrical connections. The cover assembly 40 can cooperate with the housing 10 to provide a relatively closed and reliable space for chemical reactions inside the battery.

[0131] In this embodiment, the battery cell 1 includes a cover plate assembly 40, and the heat sink 31 includes an encapsulation part 310 and a first connecting part 330. The encapsulation part 310 has an encapsulation cavity. One end of the first connecting part 330 is connected to the encapsulation part 310, and the other end is connected to the cover plate assembly 40. The heat of the first connecting part 330 can be conducted away through the cover plate assembly 40, thereby reducing the temperature of the battery cell 1.

[0132] Optionally, in some embodiments, the cover plate assembly 40 includes a cover plate 41, a pole post 42, and an adapter piece 43; the cover plate 41, the pole post 42, or the adapter piece 43 is in contact with the other end of the first connecting portion 330.

[0133] The housing 10 can be used in conjunction with the cover plate 41. Specifically, an opening can be provided on the housing 10, and the cover plate 41 can be used to close the opening to form the internal environment of the battery cell 1. In other embodiments, the cover plate 41 and the housing 10 can be integrated. Specifically, the cover plate 41 and the housing 10 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 10, the cover plate 41 is used to close the housing 10.

[0134] The electrode post 42 can be disposed on the cover plate 41, and the adapter plate 43 is located between the cover plate 41 and the electrode assembly 20. In some embodiments, the tabs 25 of multiple electrode assemblies 20 can be connected to the electrode post 42 via the adapter plate 43. There can be two electrode posts 42, namely a cathode post 42 and an anode post 42; correspondingly, there are also two adapter plates 43, namely a cathode adapter plate 43 and an anode adapter plate 43. The cathode tabs of multiple electrode assemblies 20 are connected to the cathode posts 42 via the cathode adapter plate 43, and the anode posts 42 of multiple electrode assemblies 20 are connected to the anode tabs via the anode adapter plate 43.

[0135] In this embodiment, the cover plate 41, the terminal post 42, or the adapter plate 43 typically have a large area and are directly connected to the outer casing or structural components of the battery cell 1. By setting the cover plate assembly 40 to include the cover plate 41, the terminal post 42, or the adapter plate 43, and having the other ends of the cover plate 41, the terminal post 42, or the adapter plate 43 in contact connection, heat dissipation efficiency can be improved.

[0136] In some embodiments, the first end of the electrode assembly 20 is provided with a tab 25, and the second end is not provided with a tab 25, and the second end is disposed opposite to the first end; the heat dissipation assembly 30 is disposed near the first end of the electrode assembly 20 and spaced apart from the second end of the electrode assembly 20.

[0137] The statement that the electrode assembly 20 has a tab 25 at its first end and no tab 25 at its second end means that the tab 25 is only provided at one end or one side of the electrode assembly 20.

[0138] In this embodiment, by placing the heat dissipation component 30 at the first end, the conduction path of heat from the tab 25 to the heat dissipation component 30 can be reduced, the heat dissipation efficiency can be improved, and the heat accumulation at the tab 25 where heat is absorbed faster can be reduced, thereby making the heat distribution inside the battery cell 1 more balanced.

[0139] Furthermore, the first end is the top end of the electrode assembly 20, and the second end is the bottom end of the electrode assembly 20; the direction from the top end to the bottom end is the height direction, and the ratio of the height of the heat dissipation assembly 30 to the height of the electrode assembly 20 is 50%-70%. For example, the ratio of the height of the heat dissipation assembly 30 to the height of the electrode assembly 20 is 50%, 55%, 60%, 65%, or 70%, etc. In this way, sufficient contact area can be ensured between the heat dissipation assembly 30 and the electrode assembly 20 to achieve effective heat dissipation efficiency without increasing the weight of the battery cell 1, which is beneficial to the lightweighting of the battery cell 1.

[0140] In some embodiments, the heat sink 31 includes at least two layers of metal foil; the phase change material 32 includes organic phase change material, inorganic phase change material or eutectic material.

[0141] The heat sink 31 includes at least two layers of metal foil, which can form an encapsulation cavity to accommodate the phase change material 32. The metal foil has good thermal conductivity. Due to its thin and uniform characteristics, the metal foil can quickly conduct heat away from the heat source, effectively improving heat dissipation efficiency and contributing to the lightweighting of the battery. The metal foil is also easy to cut and shape to adapt to different space constraints.

[0142] Organic phase change materials can include paraffin wax, which has advantages such as high latent heat of phase change (generally between 150 J / g and 250 J / g), good chemical stability, non-corrosiveness, and relatively low price; or fatty acids and their esters, such as stearic acid and lauric acid. Their latent heat of phase change is also considerable, and they have good chemical stability and biodegradability.

[0143] Inorganic phase change materials can include hydrated salts, such as sodium sulfate decahydrate (Glauber's salt), which have a high latent heat of phase change, reaching approximately 250-300 J / g. The phase change temperature of hydrated salts can be adjusted by selecting different salts; or metallic and alloy phase change materials, such as some low-melting-point metal alloys, like gallium-based alloys, which have excellent thermal conductivity and can rapidly absorb and release heat. The phase change temperature of metallic and alloy phase change materials can be precisely controlled by adjusting the alloy composition.

[0144] Eutectic materials are homogeneous mixtures of binary, ternary, or multi-component phase change materials. Their melting temperature is lower than the melting point of any single component. They can be inorganic-inorganic eutectic materials, organic-organic eutectic materials, or inorganic-organic eutectic materials, etc.

[0145] In this embodiment, different phase change materials 32 have different advantages and can be selected according to actual needs during design. Among them, organic phase change materials have the advantages of stable physicochemical properties, good formability, low toxicity, low cost, and large latent heat of phase change. Inorganic phase change materials have the advantages of a wide applicable temperature range, can be used in a variety of temperature environments, have a high phase change enthalpy, can efficiently store energy and transfer heat, have good thermal stability, can work stably for a long time under harsh conditions such as high temperature, and have strong thermal conductivity and fast heat transfer speed. Eutectic materials have an excellent balance in terms of thermal performance, chemical stability, and mechanical properties, and are highly adjustable. Parameters such as phase change temperature and latent heat can be customized according to needs. They have low supercooling, are easier to release heat during cooling, have less phase separation, and improve performance stability during cyclic use.

[0146] Please refer to Figure 19 Some embodiments of this application provide a battery device 100, including a battery housing 2 and a battery cell 1 provided in any of the above embodiments, wherein the battery cell 1 is installed inside the battery housing 2.

[0147] The battery housing 2 provides a space for housing the battery cells 1, and the battery housing 2 can adopt various structures. In some embodiments, the battery housing 2 may include a first portion 201 and a second portion 202, which overlap each other, and together define a space for housing the battery cells 1. The second portion 202 may be a hollow structure with one end open, and the first portion 201 may be a plate-like structure, with the first portion 201 covering the open side of the second portion 202 so that the first portion 201 and the second portion 202 together define the space; the first portion 201 and the second portion 202 may also be hollow structures with one side open, with the open side of the first portion 201 covering the open side of the second portion 202. Of course, the battery housing 2 formed by the first portion 201 and the second portion 202 can be of various shapes, such as a cylinder, a cuboid, etc.

[0148] In the battery device 100, there can be multiple battery cells 1, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 1 are connected in both series and parallel configurations. Multiple battery cells 1 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 1 is housed within the battery casing 2. Alternatively, the battery device 100 can also consist of multiple battery cells 1 first connected in series, parallel, or in a mixed manner to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the battery casing 2. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 1.

[0149] In this embodiment, by setting the heat dissipation component 30 between two adjacent electrode components, the distance between the heat dissipation component 30 and the electrode components is short, resulting in a shorter heat conduction path and improved heat dissipation efficiency. The heat dissipation component 30 includes a heat sink 31 and a phase change material 32. The heat sink 31 has thermal conductivity and can quickly conduct the heat generated by the electrode components to the phase change material 32. The phase change material 32 can also transfer and temporarily store heat according to sensible heat (specific heat capacity) or latent heat (phase change heat). Then, the heat is transferred to the outside of the battery cell through the heat sink 31. In this process, the phase change material 32 can play a role in thermal buffering. Even under high current, when the heat generation rate is greater than the heat dissipation rate, the heat generated by the electrode components 20 can be quickly transferred to the phase change material 32. The heat accumulation position is also transferred from the electrode components 20 to the heat dissipation component 30, which alleviates the problem of excessive temperature rise caused by heat accumulation in the electrode components 20.

[0150] Please participate Figure 20 Some embodiments of this application provide an electrical device 1000, which includes an electrical component 200 and a battery device 100, wherein the battery device 100 is electrically connected to the electrical component 200.

[0151] Electrical equipment 1000 can be 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. For ease of explanation, the following embodiments use a vehicle as an example for electrical equipment 1000.

[0152] The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle, and the battery device 100 can be located at the bottom, front, or rear of the vehicle. The battery device 100 can be used to power the vehicle; for example, the battery device 100 can serve as the vehicle's operating power source. The vehicle may also include electrical components (such as controllers) used to control the power supply to the battery device 100, for example, to meet the power needs of the vehicle during starting, navigation, and driving.

[0153] In some embodiments of this application, the battery device 100 can serve not only as the operating power source for the vehicle but also as the driving power source, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle. Furthermore, the electrical equipment 1000 can be a vehicle, and the electrical components 200 can be vehicle lights (e.g., headlights, taillights, etc.), displays, dashboards, control systems (e.g., controllers), etc. The electrical equipment 1000 may also include other parts, such as a vehicle frame, with both the battery device 100 and the electrical components 200 mounted on the vehicle body.

[0154] Electrical device 200 can be any component or device capable of consuming electricity. Electrical device 200 can be a controller or electronic component, etc. The controller can be a Central Processing Unit (CPU), Digital Signal Processor (DSP), Application-Specific Integrated Circuit (ASIC), Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0155] The battery device 100 can be any of the battery devices 100 provided in the foregoing embodiments. The battery device 100 can be a device capable of providing electrical energy to the electrical device 200.

[0156] In this embodiment, a heat dissipation component is sandwiched between two adjacent electrode components, resulting in a shorter heat conduction path and improved heat dissipation efficiency. The heat dissipation component includes a heat sink 31 and a phase change material. The heat sink has thermal conductivity, which can quickly conduct the heat generated by the electrode components to the phase change material. The phase change material can also transfer and temporarily store heat based on sensible heat (specific heat capacity) or latent heat (phase change heat). The heat is then transferred to the outside of the battery cell through the heat sink. In this process, the phase change material can act as a thermal buffer. Even at high current rates, where the heat generation rate is greater than the heat dissipation rate, the heat generated by the electrode components can be quickly transferred to the phase change material. The heat accumulation location is also shifted from the electrode components to the heat dissipation component, alleviating the problem of excessive temperature rise caused by heat accumulation in the electrode components.

[0157] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0158] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0159] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A battery cell, characterized in that, include: case; Multiple electrode assemblies are housed within the housing; A heat dissipation assembly is sandwiched between two adjacent electrode assemblies; The heat dissipation component includes a heat sink and a phase change material. The heat sink has an encapsulation cavity, and the phase change material is housed within the encapsulation cavity.

2. The battery cell according to claim 1, characterized in that, The outermost current collector of the electrode assembly includes a smooth surface area.

3. The battery cell according to claim 2, characterized in that, The electrode assembly is a wound structure. One ring of the wound structure includes a cathode electrode, a first diaphragm, an anode electrode, and a second diaphragm stacked from the inside out. The outer surface of the anode current collector of the outermost ring of the electrode assembly includes the smooth surface area. The second diaphragm of the outermost ring covers the smooth surface area and is in contact with the heat sink.

4. The battery cell according to claim 3, characterized in that, The electrode assembly has a flat structure, and the anode electrode has one more turn than the cathode electrode. The outermost anode electrode has its tail end located on the plane of the flat structure near the heat sink. The outer surface of the anode current collector of the outermost anode electrode, from its tail end to the corner, is the smooth surface area.

5. The battery cell according to any one of claims 1-4, characterized in that, The heat sink includes an encapsulation portion and a first connecting portion. The encapsulation portion has the encapsulation cavity. One end of the first connecting portion is connected to the encapsulation portion, and the other end is connected to the tab of the electrode assembly.

6. The battery cell according to claim 5, characterized in that, The encapsulation portion includes a first encapsulation layer and a second encapsulation layer connected at the edges, and the encapsulation cavity is formed between the first encapsulation layer and the second encapsulation layer.

7. The battery cell according to claim 6, characterized in that, The first connecting part includes: The first connecting layer has one end connected to the edge of the first encapsulation layer and the other end in contact with the first tab of the electrode assembly; The second connecting layer has one end connected to the edge of the second encapsulation layer and the other end in contact with the first tab of the electrode assembly.

8. The battery cell according to claim 7, characterized in that, The first connecting layer and the second connecting layer are stacked and are in contact with the first tab of the same electrode assembly.

9. The battery cell according to claim 7, characterized in that, The first connecting layer is in contact with the first tab of one of the two adjacent electrode assemblies; The second connecting layer is in contact with the first tab of another electrode assembly of the two adjacent electrode assemblies.

10. The battery cell according to claim 6, characterized in that, The first encapsulation layer, the second encapsulation layer, and the first connecting portion are integrally formed.

11. The battery cell according to claim 5, characterized in that, The width of the encapsulation part is greater than the width of the first connecting part.

12. The battery cell according to any one of claims 1-4, characterized in that, The heat sink includes: The packaging section has the packaging cavity. First connecting part; one end of the first connecting part is connected to the encapsulation part, and the other end is in contact with the first tab of the electrode assembly; Second connecting part; one end of the second connecting part is connected to the encapsulation part, and the other end is in contact with the second tab of the electrode assembly; At least one of the first connecting part and the second connecting part is an insulating structural component.

13. The battery cell according to any one of claims 1-4, characterized in that, The battery cell also includes a cover plate assembly; the heat sink includes an encapsulation part and a first connecting part, the encapsulation part has the encapsulation cavity, one end of the first connecting part is connected to the encapsulation part, and the other end is connected to the cover plate assembly.

14. The battery cell according to claim 13, characterized in that, The cover plate assembly includes a cover plate, a pole, and an adapter plate; the cover plate, the pole, or the adapter plate is in contact with the other end of the first connecting portion.

15. The battery cell according to any one of claims 1-4, characterized in that, The electrode assembly has a tab at its first end and no tab at its second end, and the second end is positioned opposite to the first end; the heat dissipation assembly is positioned close to the first end of the electrode assembly and spaced apart from the second end of the electrode assembly.

16. The battery cell according to claim 15, characterized in that, The first end is the top end, and the second end is the bottom end; the direction from the top end to the bottom end is the height direction, and the ratio of the height of the heat dissipation component to the height of the electrode component is 50%-70%.

17. The battery cell according to any one of claims 1-4, characterized in that, The heat sink comprises at least two layers of metal foil; the phase change material comprises organic phase change material, inorganic phase change material or eutectic material.

18. A battery device, characterized in that, It includes a battery housing and a battery cell as described in any one of claims 1 to 17, wherein the battery cell is installed in the battery housing.

19. An electrical appliance, characterized in that, It includes an electrical device and a battery device as described in claim 18, wherein the battery device is electrically connected to the electrical device.

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