Battery monomer and manufacturing method thereof, battery and electric equipment

Abstract

A battery cell (20) and a manufacturing method thereof, a battery (100) and an electric device, the battery cell (20) comprising a housing (211), an end cap (212a), an electrolyte, an electrode assembly (22) and a blocking member (212b), the housing (211) having a first opening (106); an end cover (212a) covers the first opening (106), and the end cover (212a) and the shell (211) are connected in a sealed mode to form a connecting part (211c); the electrolyte is arranged in the shell (211); the electrode assembly (22) is arranged in the shell (211); and the blocking piece (212b) is connected with the end cover (212a) and the shell (211), and is positioned on one side, facing the interior of the battery monomer (20), of the connecting part (211c).

Description

Battery cells and their manufacturing methods, batteries and electrical devices Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell and its manufacturing method, a battery, and an electrical device. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] Batteries are widely used in portable electronic devices, electric vehicles, power tools, drones, energy storage devices, and other fields. Improving the reliability of individual battery cells and the battery pack itself is a pressing issue in battery technology.

[0004] Summary of the Invention

[0005] This application provides a battery cell and its manufacturing method, a battery, and an electrical device, which can improve the reliability of the battery cell and the battery.

[0006] This application is achieved through the following technical solution:

[0007] In a first aspect, embodiments of this application provide a battery cell, including a housing, an end cap, an electrolyte, an electrode assembly, and a blocking member. The housing has a first opening; the end cap covers the first opening, and the end cap and the housing are sealed together to form a connection portion; the electrolyte is disposed inside the housing; the electrode assembly is disposed inside the housing; and the blocking member connects the end cap and the housing and is located on the side of the connection portion facing the interior of the battery cell.

[0008] According to the embodiments of this application, in a battery cell, a blocking member connects the end cap and the housing and is located on the side of the connection portion facing the inside of the battery cell. Therefore, it can reduce the probability of electrolyte contacting the connection portion to a certain extent, or prevent at least part of the connection portion from contacting the electrolyte, effectively alleviating the corrosion problem of electrolyte on the connection portion, thereby improving the reliability of the connection portion, reducing the risk of electrolyte leakage, and further improving the reliability of the battery cell and the battery.

[0009] According to some embodiments of this application, the end cap has a first connecting surface, the housing has a second connecting surface, and the first connecting surface and the second connecting surface are disposed opposite to each other and connected to form the connecting portion.

[0010] In the above solution, at least a portion of the blocking member is disposed between the first connecting surface and the second connecting surface, thereby reducing the probability of electrolyte entering between the first connecting surface and the second connecting surface, so that at least a portion of the connection does not come into contact with the electrolyte, effectively alleviating the corrosion problem of the connection by the electrolyte, thereby improving the reliability of the connection, reducing the risk of electrolyte leakage, and further improving the reliability of the battery cell and the battery.

[0011] According to some embodiments of this application, the portion of the blocking member disposed between the first connecting surface and the second connecting surface is an annular structure extending circumferentially along the end cap.

[0012] In the above solution, since the connecting part is a ring structure, the part of the blocking member set between the first connecting surface and the second connecting surface is a ring structure extending circumferentially along the end cap. This can block the electrode liquid from moving toward the connecting part in all directions, further reducing the probability of the electrolyte contacting the connecting part, thereby ensuring the reliability of the connecting part and reducing the risk of electrolyte leakage.

[0013] According to some embodiments of this application, the end cap has a first side facing the interior of the battery cell and a second side facing away from the interior of the battery cell, and a first outer peripheral surface connecting the first side and the second side, wherein the first connecting surface is the first outer peripheral surface; the housing has an inner peripheral surface facing the interior of the battery cell, and a portion of the inner peripheral surface forms the second connecting surface.

[0014] In the above scheme, at least a portion of the end cap extends into the housing, thereby allowing the first outer peripheral surface to be connected and fixed to the inner peripheral surface of the housing, thus forming a connecting portion. In this case, the first connecting surface is the first outer peripheral surface of the end cap, and the second connecting surface is a portion of the inner peripheral surface of the housing.

[0015] According to some embodiments of this application, the housing has a second outer peripheral surface facing away from the interior of the battery cell and an inner peripheral surface facing the interior of the battery cell, and an end face connecting the inner peripheral surface and the second outer peripheral surface, wherein the second connecting surface is the end face, and the end cap has a first side surface facing the interior of the battery cell, wherein a portion of the first side surface forms the first connecting surface.

[0016] In the above scheme, at least the portion of the end cap that connects to the housing does not extend into the housing, but is directly connected and fixed to the end face of the housing, thereby forming a connection portion. In this case, the end face of the housing near the opening is the second connection surface, and a portion of the side of the end cap near the inside of the housing in the thickness direction (i.e., the first side of the end cap facing the inside of the battery cell) is the first connection surface.

[0017] According to some embodiments of this application, the first side has a protrusion, and the first connecting surface is disposed around the protrusion.

[0018] In the above scheme, during the process of installing the end cap into the housing, the protrusion can first extend into the interior of the housing, thereby achieving the initial positioning of the end cap and the housing, ensuring the accurate installation position of the end cap and the housing, and the end cap can be more stably fixed to the housing.

[0019] It is understandable that a portion of the first side may protrude toward the interior of the battery cell to form the aforementioned protrusion.

[0020] According to some embodiments of this application, a portion of the blocking member is disposed between the protrusion and the inner peripheral surface of the housing.

[0021] In the above solution, a portion of the blocking member extends between the first connecting surface and the second connecting surface. At the same time, a portion of the blocking member is also disposed between the protrusion and the inner circumferential surface of the housing. Therefore, not only can the portion of the blocking member located between the first and second connecting surfaces prevent the electrolyte from contacting the connecting part, but the portion of the blocking member between the protrusion and the inner circumferential surface of the housing can also prevent the electrolyte from contacting the connecting part. This further reduces the probability of the electrolyte contacting the connecting part, thereby ensuring the reliability of the connecting part and reducing the risk of electrolyte leakage.

[0022] According to some embodiments of this application, the housing has an end face, the end cap has a third side face facing the interior of the battery cell and offset from the end face along the thickness direction of the end cap, and the first connecting surface is disposed around the third side face; the blocking member includes a first part and a second part connected to each other, the first part is disposed between the first connecting surface and the second connecting surface, and the second part covers at least a portion of the first side face.

[0023] In the above solution, the blocking member not only extends between the first connecting surface and the second connecting surface, but also covers part of the third side surface. As a result, the blocking member is more firmly attached, and at the same time, it further enhances the blocking member's ability to block the electrolyte and reduces the probability of the electrolyte coming into contact with the connecting part.

[0024] It should be noted that, in the scheme where the first outer peripheral surface of the end cap is constructed as a first connecting surface and connects with a portion of the inner peripheral surface of the housing to form a connecting portion, the third side surface is the first side surface on the end cap facing the inside of the battery cell; in the scheme where the end face of the housing is constructed as a second connecting surface, and a portion of the first side surface is the first connecting surface and mates with the second connecting surface to form a connecting portion, the other portion of the first side surface is the third side surface. In some embodiments of this application, the outer peripheral portion of the first side surface is the first connecting surface, and the middle region of the first side surface is the third side surface; that is, the first connecting surface surrounds the outer periphery of the third side surface.

[0025] According to some embodiments of this application, the blocking member covers the entire third side.

[0026] In the above design, when the battery cell is inverted, the third side will not come into contact with the electrolyte, further reducing the risk of end cap corrosion. Simultaneously, the entire circumferential direction of the blocking component can be connected to the inner circumferential surface of the casing, thus sealing the gap between the inner circumferential surface of the casing and the end cap towards the inside of the battery cell. This reduces the likelihood of electrolyte entering the gap, thereby improving the sealing performance of the battery cell.

[0027] According to some embodiments of this application, the second part includes a body portion and a thickened portion, the thickened portion surrounding the outer periphery of the body portion and connected to the inner peripheral surface; along the thickness direction of the end cap, the maximum thickness of the thickened portion is greater than the maximum thickness of the body portion.

[0028] In the above design, after the end cap is connected to the housing, the second part ensures that the third side has better blocking and corrosion resistance, thereby reducing the probability of the end cap being corroded by the electrolyte. Simultaneously, the thicker portion near the inner circumferential surface further isolates the electrolyte from the third side, further reducing the probability of the end cap being corroded by the electrolyte.

[0029] The initial blocking material on the third side can melt after the battery cell is heated. The thickened part is formed after the initial blocking material on the third side melts and moves to the inner circumferential surface. It is understandable that before the battery cell is heated, the thickness of the initial blocking material near the inner circumferential surface is greater than the thickness of the thickened part.

[0030] When the end cap faces downwards, the electrolyte inside the casing can be blocked not only by the second part covering the third side, but also by the fixed connection area between the end cap and the casing, thus achieving secondary sealing, reducing the risk of electrolyte leakage and improving the sealing performance of the battery cell.

[0031] According to some embodiments of this application, the thickened portion has a first side connected to the body portion and a second side connected to the first portion, and the thickness of the thickened portion gradually increases from the first side to the second side.

[0032] In the above scheme, the gradually thickened part can make the blocking performance of the second part gradually stronger in the part close to the first part, ensuring that the edge area of ​​the third side has sufficient blocking performance, and further reducing the risk of the end cap being corroded by electrolyte.

[0033] According to some embodiments of this application, the maximum thickness of the thickened portion is t, and satisfies: 0mm < t ≤ 3mm.

[0034] In the above scheme, on the one hand, it can ensure that the area of ​​the second part close to the first part has sufficient blocking performance, and on the other hand, it can ensure that the thickness of the area of ​​the second part close to the first part is not too large, so as not to have a negative impact on the energy density of the battery cell.

[0035] According to some embodiments of this application, at least a portion of the edge region of the third side is constructed as a guide ramp.

[0036] In the above scheme, when the end cap is located below the battery cell and the battery cell is heated, the blocking material initially located on the third side melts. The molten blocking material on the third side can flow downward through the guide slope under the action of gravity and move to the space between the first connecting surface and the second connecting surface.

[0037] It should be noted that in the scheme where the first outer peripheral surface of the end cap is constructed as a first connecting surface and is connected to a portion of the inner peripheral surface of the housing to form a connecting portion, the molten blocking material on the third side can flow to the first connecting surface and the second connecting surface through the guide slope; in the scheme where the end face of the housing is constructed as a second connecting surface and a portion of the first side is a first connecting surface that mates with the second connecting surface, at least a portion of the first side protrudes toward the interior of the battery cell to form a protrusion, and the guide slope can be the peripheral surface of the protrusion. The molten blocking material on the third side can first enter the gap between the protrusion or the guide slope and the inner peripheral surface of the housing, and then immerse itself between the first connecting surface and the second connecting surface through the guide slope.

[0038] According to some embodiments of this application, the angle between the guide ramp and the first connecting surface is an obtuse angle.

[0039] In the above scheme, on the one hand, it ensures that the molten blocking material can flow relatively smoothly, so that the blocking component can flow more stably between the first connecting surface and the second connecting surface, and can better seal the gap between the first connecting surface and the second connecting surface. On the other hand, it ensures that the molten blocking material has a sufficient flow speed, thereby improving the efficiency of the blocking component flowing between the first connecting surface and the second connecting surface.

[0040] According to some embodiments of this application, the guide ramp is disposed around the end cap and forms an annular region.

[0041] In the above solution, when the battery cell is heated, the blocking material initially located on the third side can move more evenly between the first and second connecting surfaces, thereby forming the blocking element of this application and improving the sealing performance between the end cap and the housing. The guide ramp can surround the coating area and further reduce the material of the end cap, thereby reducing the manufacturing cost of the end cap.

[0042] According to some embodiments of this application, the edge region of the third side is provided with a first groove, one end of the first groove extends to the first connecting surface, and at least a portion of the bottom wall of the first groove is constructed as the guide slope.

[0043] In the above scheme, the first groove can guide the molten blocking material on the third side to the space between the first connecting surface and the second connecting surface. The first groove can store a certain amount of molten blocking material. Therefore, the area of ​​the blocked material coated on the inner circumferential surface of the shell that is directly opposite the first groove is larger than the height of other areas of the inner circumferential surface coated with blocking material, thereby improving the sealing effect between the end cap and the shell to at least a certain extent.

[0044] The area on the inner circumferential surface of the shell that is not directly opposite the first groove has a gap between it and the end cap that communicates with the first groove. The molten material flowing out from the first groove coats the area on the inner circumferential surface of the shell that is not directly opposite the first groove through this gap.

[0045] Because the edge area of ​​the third side is not entirely sloping, the flow of molten material is more concentrated, and the molten material can more easily reach the space between the first and second connecting surfaces through the first groove. This reduces the likelihood that the molten material would have difficulty flowing between the first and second connecting surfaces due to the overall large size of the edge area of ​​the third side.

[0046] According to some embodiments of this application, there are multiple first grooves, and the multiple first grooves are arranged at intervals along the circumference of the end cap.

[0047] In the above scheme, after the material is blocked from melting, the molten material on the coating area can flow evenly between the first connecting surface and the second connecting surface, improving the sealing uniformity between the end cap and the inner circumferential surface of the shell. Of course, by setting multiple first grooves on the edge area of ​​the third side, the material used for the end cap can be further reduced, thus reducing the manufacturing cost of the end cap.

[0048] According to some embodiments of this application, the third side surface is further provided with a second groove, which is located at the end of the first groove away from the first connecting surface and communicates with the first groove.

[0049] In the above scheme, the initial blocking material can be stored in the second groove, and the thickness of the blocking material in the second groove is greater than the thickness of the blocking material in other areas of the third side. Therefore, after the battery cell is heated, the amount of material after the blocking material in the second groove melts can support its flow between the first connecting surface and the second connecting surface, ensuring good sealing performance between the end cap and the housing.

[0050] Of course, by setting a second groove, the material used in the end cap can be further reduced, thus reducing the manufacturing cost of the end cap.

[0051] According to some embodiments of this application, the second groove is an annular groove extending circumferentially along the third side surface.

[0052] In the above scheme, the portion of the initial blocking material in the second groove can have a sufficient amount of material after melting, and can then flow circumferentially between the first connecting surface and the second connecting surface, thereby further improving the sealing performance between the end cap and the shell.

[0053] According to some embodiments of this application, the melting point of the blocking element is greater than or equal to 85°C and less than or equal to 120°C.

[0054] In the above solution, on the one hand, the blocking component can melt when the battery cell is heated, so that the molten blocking material can flow from the third side to between the first connecting surface and the second connecting surface to perform secondary sealing on the battery cell's casing and end cap. On the other hand, the blocking component will not cause the battery cell to melt during normal use due to its low melting point, thus improving the stability of the blocking component.

[0055] According to some embodiments of this application, the blocking element includes one or more of paraffin wax, rosin, PE wax, polyolefin, stearic acid, and white oil.

[0056] In the above scheme, the blocking component can be melted after the battery cell is heated, and the molten blocking material can flow between the first connecting surface and the second connecting surface to perform secondary sealing of the end cap and the housing.

[0057] The blocking component can be made of a single material, which can be any of the materials mentioned above; of course, the blocking component can also be composed of two or more of the materials mentioned above.

[0058] Secondly, embodiments of this application provide a battery including the aforementioned battery cell. Because the battery according to embodiments of this application is equipped with the aforementioned battery cell, the end cap of the battery has stronger corrosion resistance, effectively reducing the risk of the end cap being corroded by the electrolyte, and also reducing the risk of electrolyte leakage from the battery.

[0059] According to some embodiments of this application, the end cap is located below the housing along the direction of gravity. Therefore, when the battery cell is inverted and subjected to high-temperature baking, the molten blocking material can flow under gravity to the side of the connector facing the inside of the battery cell, thereby reducing the probability of the electrolyte contacting the connector.

[0060] Thirdly, embodiments of this application provide an electrical device including the aforementioned battery cell or battery. Because the electrical device according to embodiments of this application is equipped with the aforementioned battery cell or battery, the power supply stability of the electrical device is improved.

[0061] Fourthly, embodiments of this application provide a method for manufacturing a single battery cell, comprising:

[0062] An end cap assembly is provided, the end cap assembly including an end cap and a blocking member, the blocking member being disposed on one side of the end cap in the thickness direction;

[0063] A housing is provided, the housing having a first opening;

[0064] Provide an electrode assembly, and install the electrode assembly into the housing;

[0065] The end cap assembly is placed over the first opening, with the blocking member facing the interior of the housing;

[0066] The end cap and the housing are connected to form an assembly;

[0067] The assembly is heated to melt the blocking element and connect the end cap and the housing;

[0068] Cool the assembly to solidify the blocking component;

[0069] Electrolyte is injected into the housing.

[0070] According to the battery cell manufacturing method of the present application embodiment, the electrode assembly can be installed inside the housing, and the assembly can be heated so that the molten blocking component flows between the end cap and the housing, thereby blocking the electrolyte to a certain extent, reducing the probability of contact between the electrolyte and the connection part, and thus reducing the occurrence of battery cell leakage.

[0071] According to some embodiments of this application, when the assembly is heated, the end cap assembly is oriented downwards.

[0072] In the above scheme, the molten blocking material can flow towards the space between the end cap and the shell under the action of gravity, so that the initial blocking material can diffuse between the end cap and the shell after cooling, at least to a certain extent blocking the electrolyte from moving towards the connection. Attached Figure Description

[0073] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0074] Figure 1 is a schematic diagram of the vehicle provided in an embodiment of this application;

[0075] Figure 2 is an exploded view of the battery provided in an embodiment of this application;

[0076] Figure 3 is an exploded view of a single battery cell provided in an embodiment of this application;

[0077] Figure 4 is a front view of the end cap assembly (not assembled into the housing) provided in an embodiment of this application;

[0078] Figure 5 is a side view of the end cap assembly (not assembled into the housing) provided in an embodiment of this application;

[0079] Figure 6 is a front view of the end cap assembly provided in an embodiment of this application;

[0080] Figure 7 is a side view of the end cap assembly provided in an embodiment of this application;

[0081] Figure 8 is a side view of an end cap assembly provided in another embodiment of this application;

[0082] Figure 9 is a side view of an end cap assembly provided in another embodiment of this application;

[0083] Figure 10 is a side view of the end cap provided in an embodiment of this application;

[0084] Figure 11 is a partial enlarged view provided by circle A in Figure 10;

[0085] Figure 12 is a cross-sectional view of a battery cell provided in an embodiment of this application;

[0086] Figure 13 is a partially enlarged schematic diagram of circle B in Figure 12;

[0087] Figure 14 is a schematic diagram of the end cap and housing fitting together according to an embodiment of this application;

[0088] Figure 15 is a magnified view of a portion of circle F in Figure 14;

[0089] Figure 16 is a schematic diagram of the end cap and housing fitting together according to another embodiment of this application;

[0090] Figure 17 is a magnified view of a portion of circle G in Figure 16;

[0091] Figure 18 is a schematic diagram of the end cap and housing fitting together according to another embodiment of this application;

[0092] Figure 19 is a magnified view of circle H in Figure 18;

[0093] Figure 20 is a schematic diagram of the end cap and housing fitting together according to another embodiment of this application;

[0094] Figure 21 is a magnified view of circled C in Figure 20;

[0095] Figure 22 is a schematic diagram of the end cap and housing fitting together according to another embodiment of this application;

[0096] Figure 23 is a magnified view of circled D in Figure 22;

[0097] Figure 24 is a schematic diagram of the end cap and housing fitting together according to another embodiment of this application;

[0098] Figure 25 is a magnified view of circle E in Figure 24;

[0099] Figure 26 is a schematic diagram of the end cap and housing fitting together according to another embodiment of this application;

[0100] Figure 27 is a magnified view of a portion of circle J in Figure 26;

[0101] Figure 28 is a flowchart of a method for manufacturing a battery cell according to an embodiment of this application.

[0102] Icons: Vehicle 1000, Battery 100, Controller 200, Motor 300, Housing 10, Battery Cell 20, First Sub-Housing 11, Second Sub-Housing 12, Housing 21, Electrode Assembly 22, Electrode Terminal 25, Housing 211, Connector 211c, End Cap Assembly 212, End Cap 212a, Protrusion 212a1, Block 212b, First Part 212c1, Second Part 212c2, Third Part 212c3 First side 101, coating area 101a, blank area 101b, third side 101c, second side 102, first outer peripheral surface 103, body part 212b1, thickened part 212b2, first side a, second side b, guide slope 108, first groove 104a, second groove 104b, first opening 106, inner peripheral surface 107, end face 105, second outer peripheral surface 109, first connecting surface M1, second connecting surface M2. Detailed Implementation

[0103] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0104] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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 some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0105] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0106] In this application, the reference to "embodiment" means that a specific 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 in 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 in this application can be combined with other embodiments.

[0107] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0108] 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, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0109] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0110] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0111] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0112] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0113] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0114] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0115] The battery cell may be, but is not limited to, lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc.

[0116] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0117] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0118] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0119] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0120] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used.

[0121] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0122] As an example, the negative electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, or made of carbon, nickel, or titanium, etc.

[0123] In some embodiments, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0124] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in batteries. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0125] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0126] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0127] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0128] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0129] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0130] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0131] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0132] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0133] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0134] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0135] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0136] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0137] In some implementations, the electrode assembly is a stacked structure.

[0138] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0139] In some embodiments, the housing includes an end cap and a casing, the casing having an opening, and the end cap closing the opening to form a sealed space for accommodating substances such as electrode assemblies and electrolytes. The casing may have one or more openings. The end cap may also be provided one or more times.

[0140] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab of the electrode assembly. The electrode terminal can be directly connected to the tab or indirectly connected to the tab via an adapter. The electrode terminal can be located on the end cap or on the housing.

[0141] In some implementations, an explosion-proof valve is provided on the housing. The explosion-proof valve is used to release the internal pressure of the battery cells.

[0142] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. There are no particular limitations in the embodiments of this application.

[0143] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0144] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0145] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0146] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0147] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0148] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide applicability, and low self-discharge coefficient, making them an important component of the current development of new energy.

[0149] The development of battery technology must take into account multiple design factors, such as energy density, discharge capacity, charge-discharge rate and other performance parameters. In addition, battery assembly efficiency also needs to be considered.

[0150] Please refer to Figure 3, which is an exploded view of a battery cell provided in some embodiments of this application. As shown in Figure 3, the battery cell 20 includes a housing 21, an electrode assembly 22, and electrode terminals 25. The housing 21 includes a shell 211 and an end cap assembly 212. The shell 211 has an opening, and the end cap assembly 212 closes the opening to isolate the internal environment of the battery cell 20 from the external environment.

[0151] The housing 211 is a component used to cooperate with the end cap assembly 212 to form the internal environment of the battery cell 20, wherein the formed internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap assembly 212 can be independent components. The housing 211 can have various shapes and sizes. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The housing 211 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0152] End cap assembly 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap assembly 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap assembly 212 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap assembly 212 is less prone to deformation under pressure and impact, enabling battery cell 20 to have higher structural strength and improved reliability. Functional components such as electrode terminals can be provided on end cap assembly 212. Electrode terminals can be used for electrical connection with electrode assembly 22 to output or input electrical energy to battery cell 20. The material of end cap assembly 212 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose special limitations on this. In some embodiments, an insulating structure may also be provided inside the end cap assembly 212. The insulating structure can be used to isolate the electrical connection components within the housing 211 from the end cap assembly 212 to reduce the risk of short circuits. For example, the insulating structure may be made of plastic, rubber, etc.

[0153] Electrode assembly 22 is the component in the battery cell 20 where electrochemical reactions occur. The casing 211 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets to separate them and prevent internal short circuits. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly, while the portions without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or at opposite ends. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0154] End caps are typically fixed to the housing to seal the openings on the housing, thereby isolating the internal and external spaces of the housing and creating a relatively sealed space inside the housing.

[0155] During use, some batteries require assembly and use with the individual cells inverted, according to customer's optimized grouping requirements, with the end caps located at the bottom. In this case, the side of the end cap facing inwards from the battery cell can directly contact the electrolyte, which may corrode the end cap and even cause leakage from the casing due to electrolyte corrosion.

[0156] In addition, since the end cap is fixedly connected to the housing, there is a fixed connection area between the end cap and the housing. When the end cap is located below the battery cell and the fixed connection area fails, the probability of electrolyte leakage increases.

[0157] While leakage from a single battery cell may affect its performance, it won't significantly impact the cell's safety. However, considering the overall system structure of the battery module or pack, electrolyte leakage can lead to electrolyte sparking and thermal runaway if a high-voltage circuit exists in that area.

[0158] To address this issue, this application proposes a battery cell that can alleviate the problem of end cap corrosion and improve battery sealing.

[0159] According to embodiments of this application, the battery cell 20 may include a housing 211, an end cap 212a, an electrode liquid, an electrode assembly 22, and a blocking member 212b.

[0160] As shown in Figures 3 and 6-27, the housing 211 has a first opening 106, through which the electrode assembly 22 can be installed into the receiving space of the housing 211. Of course, after the end cap 212a is connected to the housing 211, the electrode fluid can also be injected into the housing.

[0161] The end cap 212a can be made of a high-strength material, for example, the end cap 212a can be a metal part, and similarly, the housing 211 can also be a metal part.

[0162] The end cap 212a can cover the first opening 106, thereby closing the first opening 106. The end cap 212a and the housing 211 together enclose a space isolated from the outside world, where the electrode assembly 22 and the electrolyte can be placed.

[0163] The end cap 212a can be sealed to the housing 211 to form a connecting portion 211c. The end cap 212a can be fixedly connected to the housing 211, so the connecting portion 211c can be a fixed connection area formed after the end cap 212a and the housing 211 are fixed.

[0164] For example, the end cap 212a can be welded to the housing 211, so that the connecting part 211c is the weld between the end cap 212a and the housing 211; or the end cap 212a can be bonded to the housing 211, so that the connecting part 211c is the adhesive between the end cap 212a and the housing 211.

[0165] The blocking component 212b can be an insulating component, or it can be non-insulating, as long as it can at least to some extent prevent the electrolyte from entering the connection part 211c.

[0166] The blocking member 212b connects the end cap 212a and the housing 211, and is located on the side of the connecting part 211c facing the inside of the battery cell 20.

[0167] In other words, there is a gap between the end cap 212a and the housing 211. Even if the gap is small, the blocking member 212b can enter into the gap between the end cap 212a and the housing 211. This can, to a certain extent, prevent the electrolyte from contacting the connection part 211c, thereby reducing the risk of corrosion of the connection part 211c.

[0168] According to the embodiments of this application, in the battery cell 20, the blocking member 212b connects the end cap 212a and the housing 211, and is located on the side of the connecting portion 211c facing the interior of the battery cell 20. Therefore, it can reduce the probability of electrolyte contact with the connecting portion 211c to a certain extent, or prevent at least a portion of the connecting portion 211c from contacting the electrolyte, effectively alleviating the corrosion problem of the connecting portion 211c by the electrolyte, thereby improving the reliability of the connecting portion 211c, reducing the risk of electrolyte leakage, and further improving the reliability of the battery cell 20 and the battery.

[0169] In some embodiments of this application, the end cap 212a has a first connecting surface M1, and the housing 211 has a second connecting surface M2. The first connecting surface M1 and the second connecting surface M2 are disposed opposite to each other and connected to form a connecting portion 211c. For example, at least a portion of the first connecting surface M1 and the second connecting surface M2 can be welded to form the connecting portion 211c.

[0170] The end cap 212a can be generally plate-shaped.

[0171] At least a portion of the blocking member 212b is disposed between the first connecting surface M1 and the second connecting surface M2, and is located on the side of the connecting portion 211c facing the inside of the battery cell 20.

[0172] In other words, there is an unavoidable gap between the first connecting surface M1 and the second connecting surface M2 (even if the gap is small, the gap still exists). Therefore, at least a portion of the blocking member 212b is disposed between the first connecting surface M1 and the second connecting surface M2, which can prevent the electrolyte from contacting the connecting part 211c to a certain extent, thereby reducing the risk of corrosion of the connecting part 211c.

[0173] At least a portion of the blocking member 212b is disposed between the first connecting surface M1 and the second connecting surface M2, which can reduce the probability of the electrolyte coming into contact with the connecting part 211c to a certain extent, or prevent at least a portion of the connecting part 211c from coming into contact with the electrolyte, effectively alleviating the corrosion problem of the connecting part 211c by the electrolyte, thereby improving the reliability of the connecting part 211c, reducing the risk of electrolyte leakage, and further improving the reliability of the battery cell 20 and the battery.

[0174] In some embodiments of this application, the end cap 212a and the housing 211 can be fixed together by welding. There is a welding area between the end cap 212a and the housing 211, and the end cap 212a and the housing 211 can be fixedly connected through the welding area.

[0175] The end cap 212a and the housing 211 can be fixed together by adhesive bonding. There is an adhesive area between the end cap 212a and the housing 211, and the end cap 212a and the housing 211 can be fixedly connected through this adhesive area.

[0176] Of course, the end cap 212a and the housing 211 in this embodiment of the application can be fixedly connected in other ways, and this application does not limit this.

[0177] It should be noted that the aforementioned welding area or bonding area can fix the end cap 212a and the housing 211 together. In other words, the end cap 212a and the housing 211 are mainly fixed together through the welding area or bonding area. The aforementioned welding area or bonding area can all be referred to as the connecting part 211c.

[0178] According to some embodiments of this application, at least a portion of the blocking member 212b is disposed between the first connecting surface M1 and the second connecting surface M2, and the portion of the blocking member 212b disposed between the first connecting surface M1 and the second connecting surface M2 is an annular structure that extends circumferentially along the end cap 212a.

[0179] Since the connecting part 211c is a ring structure, the portion of the blocking member 212b disposed between the first connecting surface M1 and the second connecting surface M2 is a ring structure extending circumferentially along the end cap 212a. This can completely block the electrode liquid from moving toward the connecting part 211c, further reducing the probability of the electrolyte contacting the connecting part 211c, thereby ensuring the reliability of the connecting part 211c and reducing the risk of electrolyte leakage.

[0180] According to some embodiments of this application, as shown in Figures 14-19, the end cap 212a has a first side 101 facing the interior of the battery cell 20 and a second side 102 facing away from the interior of the battery cell 20, and a first outer peripheral surface 103 connecting the first side 101 and the second side 102, wherein the first connecting surface M1 is the first outer peripheral surface 103; the housing 211 has an inner peripheral surface 107 facing the interior of the battery cell 20, and a portion of the inner peripheral surface 107 forms the second connecting surface M2.

[0181] Along the thickness direction of the end cap 212a, the end cap 212a has a first side surface 101 and a second side surface 102. The first side surface 101 faces the interior of the housing 211, and the second side surface 102 faces away from the interior of the housing 211. That is, after the battery cell 20 is assembled, the first side surface 101 is the inner side surface of the end cap 212a, and the second side surface 102 is the outer side surface of the end cap 212a.

[0182] Thus, at least a portion of the end cap 212a extends into the housing 211, allowing the first outer peripheral surface 103 to be connected and fixed to the inner peripheral surface 107 of the housing 211, thereby forming the connecting portion 211c. At this time, the first connecting surface M1 is the first outer peripheral surface 103 of the end cap 212a, and the second connecting surface M2 is a portion of the inner peripheral surface 107 of the housing 211.

[0183] According to some embodiments of this application, as shown in Figures 20-25, the housing 211 has a second outer peripheral surface 109 facing away from the interior of the battery cell 20 and an inner peripheral surface 107 facing the interior of the battery cell 20, and an end surface 105 connecting the inner peripheral surface 107 and the second outer peripheral surface 109, wherein the second connecting surface M2 is the end surface 105, and the end cap 212a has a first side surface 101 facing the interior of the battery cell 20, wherein a portion of the first side surface 101 forms the first connecting surface M1.

[0184] At least the portion of the end cap 212a that connects to the housing 211 does not extend into the housing 211, but is directly connected and fixed to the end face 105 of the housing 211, thus forming a connecting portion 211c. In this case, the end face 105 of the housing 211 near the opening 106 is the second connecting surface M2, and a portion of the first side surface 101 is the first connecting surface M1. Alternatively, the portion of the end cap 211 on the side surface near the interior of the housing 211 in the thickness direction, opposite to the end face 105, is the first connecting surface M1.

[0185] According to some embodiments of this application, as shown in Figures 14-25, the end cap 212a has a first outer peripheral surface 103 and a second side surface 102 facing away from the interior of the battery cell 20. The first outer peripheral surface 103 is connected to the first connecting surface M1 and the second side surface 102.

[0186] In other words, the first connecting surface M1 and the second side surface 102 can be arranged opposite to each other in the thickness direction of the end cap 212a, the first outer peripheral surface 103 connects the second side surface 102 and the first connecting surface M1, and the first connecting surface M1 is connected and fixed to the end surface 105 of the housing 211.

[0187] According to some embodiments of this application, as shown in Figures 26-27, a protrusion 212a1 is formed on the side of the end cap 212a facing the inside of the battery cell 20, and a first connecting surface M1 is disposed around the protrusion 212a1.

[0188] In the above scheme, during the process of installing the end cap 212a onto the housing 211, the protrusion 212a1 can first extend into the interior of the housing 211, thereby achieving the initial positioning of the end cap 212a and the housing 211, ensuring the accurate installation position of the end cap 212a and the housing 211, and the end cap 212a can be more stably fixed onto the housing 211.

[0189] It is understood that a portion of the first side 101 may protrude toward the interior of the battery cell 20 to form the aforementioned protrusion 212a1.

[0190] According to some embodiments of this application, as shown in FIG27, a portion (third portion 212c3) of the blocking member 212b is disposed between the protrusion 212a1 and the inner peripheral surface 107 of the housing 211.

[0191] In the above solution, a portion of the blocking member 212b extends between the first connecting surface M1 and the second connecting surface M2. At the same time, a portion of the blocking member 212b is also disposed between the protrusion 212a1 and the inner peripheral surface 107 of the housing 211. Therefore, not only can the portion of the blocking member 212b located between the first connecting surface M1 and the second connecting surface M2 prevent the electrolyte from contacting the connecting part 211c, but the portion of the blocking member 212b between the protrusion 212a1 and the inner peripheral surface 107 of the housing 211 can also prevent the electrolyte from contacting the connecting part 211c. This further reduces the probability of the electrolyte contacting the connecting part 211c, thereby ensuring the reliability of the connecting part 211c and reducing the risk of electrolyte leakage.

[0192] According to some embodiments of this application, as shown in Figures 14-25, the housing 211 has an end face 105, and the end cap 212a has a third side face 101c facing the interior of the battery cell 20 and offset from the end face 105 along the thickness direction of the end cap 212a. A first connecting surface M1 is disposed around the third side face 101c. The blocking member 212b includes a first part 212c1 and a second part 212c2 connected to each other. The first part 212c1 is disposed between the first connecting surface M1 and the second connecting surface M2, and the second part 212c2 covers at least a portion of the first side face 101.

[0193] In the above solution, the blocking member 212b not only extends between the first connecting surface M1 and the second connecting surface M2, but also covers a part of the third side surface 101c. As a result, the blocking member 212b is more firmly attached, and at the same time, it further enhances the ability of the blocking member 212b to block the electrolyte and reduces the probability of the electrolyte coming into contact with the connecting part 211c.

[0194] In addition, since the blocking member 212b covers at least a portion of the third side 101c, the probability of the electrode liquid coming into contact with the end cap 212a is reduced, thus alleviating the problem of electrolyte corrosion on the end cap 212a.

[0195] The first connecting surface M1 is arranged around the third side surface 101c. At this time, the first connecting surface M1 can be coplanar with the third side surface 101c. Of course, the first connecting surface M1 can also be at a certain angle to the first side surface 101. For example, the first connecting surface M1 is perpendicular to the first side surface 101.

[0196] It should be noted that in the embodiment where the first outer peripheral surface 103 of the end cap 212a is configured as the first connecting surface M1 and is connected to a portion of the inner peripheral surface 107 of the housing 211 to form a connecting portion 211c, the third side surface 101c is the first side surface 101 on the end cap 212a facing the interior of the battery cell 20; in the embodiment where the end surface 105 of the housing 211 is configured as the second connecting surface M2, and a portion of the first side surface 101 is formed by the first connecting surface M1 and the second connecting surface M2 cooperating to form the connecting portion 211c, the other portion of the first side surface 101 is the third side surface 101c. In some embodiments of this application, the outer peripheral portion of the first side surface 101 is the first connecting surface M1, and the middle region of the first side surface 101 is the third side surface 101c, that is, the first connecting surface M1 surrounds the outer periphery of the third side surface 101c.

[0197] According to some embodiments of this application, as shown in Figures 16-19 and 22-25, the blocking member 212b covers the entire third side 101.

[0198] In the above scheme, when the battery cell 20 is inverted, the third side 101c will not come into contact with the electrolyte, further reducing the risk of corrosion of the end cap 212a. Simultaneously, the entire circumferential direction of the blocking member 212b can be connected to the inner circumferential surface 107 of the housing 211, thereby sealing the gap between the inner circumferential surface 107 of the housing 211 and the end cap 212a towards the inside of the battery cell 20, reducing the probability of electrolyte entering this gap, and thus improving the sealing performance of the battery cell 20.

[0199] In some embodiments of this application, the housing 211 further has an inner peripheral surface 107 facing the interior of the housing 211 (i.e., the receiving space), the inner peripheral surface 107 can enclose the receiving space of the housing 211 and the first opening 106.

[0200] The inner circumferential surface 107 can surround the first side surface 101. That is, a part of the end cap 212a can be located inside the housing 211. The end cap 212a may not be covered on the end face 105 of the housing 211 near the end cap 212a. The end face of the housing 211 near the end cap 212a can be exposed. The entire area of ​​the first side surface 101 can be located inside the housing 211.

[0201] In some embodiments of this application, the blocking member 212b covers at least a portion of the third side 101c, that is, a portion of the third side 101c may be covered by the blocking member 212b, or the entire third side 101c may be covered by the blocking member 212b.

[0202] Therefore, the blocking member 212b can insulate at least a portion of the third side 101c. When the end cap 212a is located below the battery cell 20, the contact area between the third side 101c and the electrolyte can be reduced, thereby reducing the risk of corrosion of the end cap 212a.

[0203] In some embodiments of this application, a portion of the blocking member 212b may extend between the first connecting surface M1 and the second connecting surface M2, and a portion of the blocking member 212b may also contact the inner peripheral surface 107 of the housing 211 (the inner peripheral surface 107 is the portion that is not opposite to the first connecting surface M1).

[0204] This can further reduce the probability of contact between the electrolyte and the connection 211c, reduce the risk of electrolyte corrosion of the connection 211c, and thus reduce the risk of leakage of the battery cell 20.

[0205] Furthermore, the fixed connection area between the end cap 212a and the housing 211 (i.e., the connection portion 211c) is a primary seal, while the blocking member 212b connected to the inner circumferential surface 107 provides a secondary seal. This improves the sealing effect of the battery cell 20 and reduces the probability of electrolyte leakage.

[0206] It is understandable that the blocking member 212b can extend into the gap between the first connecting surface M1 and the second connecting surface M2, and can even extend into the gap of the fixed connection area (connecting part 211c) between the end cap 212a and the housing 211.

[0207] In some embodiments of this application, the blocking member 212b further includes a third part 212c3, which can be fixed to the inner peripheral surface 107 of the housing 211. The molten blocking material can flow not only between the first connecting surface M1 and the second connecting surface M2, but also to the inner peripheral surface 107 of the housing 211.

[0208] According to some embodiments of this application, as shown in Figures 6-9, the blocking member 212b covers the entire third side surface 101c. That is, the entire area of ​​the third side surface 101c is covered by the blocking member 212b, and there is no exposed part of the third side surface 101c.

[0209] Therefore, when the battery cell 20 is inverted, the third side 101c will not come into contact with the electrolyte, further reducing the risk of corrosion of the end cap 212a. Simultaneously, the entire circumferential direction of the blocking member 212b can be connected to the inner circumferential surface 107, thus sealing the gap between the inner circumferential surface 107 and the end cap 212a towards the inside of the battery cell 20, reducing the probability of electrolyte entering this gap, thereby improving the sealing performance of the battery cell 20.

[0210] In some embodiments of this application, the melting point of the blocking member 212b is greater than or equal to 85° and less than or equal to 120°. For example, the melting point of the blocking member 212b may be 85°, 90°, 95°, 100°, 105°, 110°, 115° or 120°.

[0211] It should be noted that the melting point of the above-mentioned blocking member 212b is only some specific embodiments of this application. As long as the melting point of the blocking member 212b meets the above range, it is within the protection scope of this application.

[0212] Since the melting point of the blocking member 212b meets the above-mentioned range, after the end cap 212a is connected to the housing 211, on the one hand, the blocking member 212b can melt when the battery cell 20 is heated (baking), so that the molten blocking material can flow to the space between the first connecting surface M1 and the second connecting surface M2, and even flow to the fixed connection area (i.e., the connection part 211c) of the housing 211 and the end cap 212a, to perform secondary sealing on the housing 211 and the end cap 212a of the battery cell 20. On the other hand, the blocking member 212b will not melt during normal use due to its low melting point, thus improving the stability of the blocking member 212b.

[0213] In some embodiments of this application, the melting point of the blocking member 212b is greater than or equal to 90° and less than or equal to 110°. For example, the melting point of the blocking member 212b may be 90°, 96°, 102°, 108° or 110°.

[0214] It should be noted that the melting point of the above-mentioned blocking member 212b is only some specific embodiments of this application. As long as the melting point of the blocking member 212b meets the above range, it is within the protection scope of this application.

[0215] Since the melting point of the blocking member 212b meets the above-mentioned range, after the end cap 212a is connected to the housing 211, on the one hand, the blocking member 212b can melt more easily when the battery cell 20 is heated (baking), so that the molten blocking material can flow more easily between the first connecting surface M1 and the second connecting surface M2, and even flow to the fixed connection area (i.e., the connection part 211c) of the housing 211 and the end cap 212a of the battery cell 20 to perform secondary sealing. On the other hand, the blocking member 212b will not melt during normal use due to the low melting point, which further improves the stability of the blocking member 212b.

[0216] In some embodiments of this application, the blocking element 212b may include one or more of paraffin wax, rosin, PE wax, polyolefin, stearic acid, and white oil. Thus, the blocking element 212b can melt after the battery cell 20 is heated, and the molten blocking material can flow between the first connecting surface M1 and the second connecting surface M2 to provide a secondary seal between the end cap 212a and the housing 211.

[0217] It is understood that the blocking element 212b can be made of a single material, which can be any of the materials mentioned above; of course, the blocking element 212b can also be composed of two or more of the materials mentioned above.

[0218] According to some embodiments of this application, as shown in Figures 8-9, the second part 212c2 includes a body part 212b1 and a thickened part 212b2. The thickened part 212b2 surrounds the outer periphery of the body part 212b1, that is, the thickened part 212b2 can extend along the circumference of the body part 212b1, and the thickened part 212b2 is a ring structure surrounding the body part 212b1.

[0219] After the end cap 212a is connected to the housing 211, the second part 212c2 ensures that the first side 101 has better insulation and corrosion resistance, thereby reducing the probability of the end cap 212a being corroded by the electrolyte. At the same time, the thickened part 212b2 located on the outer periphery of the body part 212b1 has a greater thickness, which can further isolate the electrolyte from the third side 101c, further reducing the probability of the end cap 212a being corroded by the electrolyte.

[0220] The initial blocking material on the third side 101c can melt after the battery cell 20 is heated. The thickened portion 212b2 is formed after the initial blocking material on the third side 101c melts and moves between the first connecting surface M1 and the second connecting surface M2. It can be understood that before the battery cell 20 is heated, the thickness of the portion of the initial blocking material near the first connecting surface M1 and the second connecting surface M2 is greater than the thickness of the thickened portion 212b2.

[0221] When the end cap assembly 212 is facing downwards, the electrolyte inside the housing 212 can be blocked not only by the second part 212c2 covering the third side 101c, but also by the fixed connection area between the end cap 212a and the housing 211, thereby achieving secondary sealing, reducing the risk of electrolyte leakage and improving the sealing performance of the battery cell 20.

[0222] In some embodiments of this application, as shown in FIG9, the thickened portion 212b2 has a first side a and a second side b. The first side a is connected to the main body portion 212b1, and the second side b is connected to the first portion 212c1. The thickness of the thickened portion 212b2 gradually increases from the first side a to the second side b.

[0223] As the name suggests, the first side a and the second side b are spaced apart, thus ensuring that the thickened part 212b2 has a certain width.

[0224] From the first side a to the second side b, the thickness of the thickened portion 212b2 gradually increases. That is, the thickness of the thickened portion 212b2 near the first part 212c1 is greater than the thickness of the thickened portion 212b2 away from the first part 212c1. In other words, the closer the thickened portion 212b2 is to the first part 212c1, the greater its thickness. This improves the insulation and isolation capabilities of the portion of the second part 212c2 near the first part 212c1, thereby better isolating the first side 101 from the electrolyte, reducing the ability of the end cap 212a to be corroded by the electrolyte, and improving the sealing performance of the battery cell 20.

[0225] The gradually thickened portion 212b2 allows the blocking performance of the second portion 212c2 to gradually increase as it approaches the first portion 212c1, ensuring that the edge region of the third side 101c has sufficient blocking performance and further reducing the risk of the end cap 212a being corroded by the electrolyte.

[0226] In some embodiments of this application, as shown in FIG8, the thickness of the thickened portion 212b2 is t, which satisfies: 0mm < t ≤ 3mm. For example, the thickness of the thickened portion 212b2 can be 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, or 3mm.

[0227] The thickness of the thickened portion 212b2 described above is only a few specific examples of this application. As long as the thickness of the thickened portion 212b2 meets the above range, it is within the protection scope of this application.

[0228] Since the thickness of the thickened portion 212b2 meets the above range, it can be known that the initial blocking material on the third side 101c is thicker in the part between the first connecting surface M1 and the second connecting surface M2. This ensures that the thickened portion 212b2 has sufficient thickness when the molten material cools after melting, and also prevents the thickness of the thickened portion 212b2 from being too large and affecting the energy density of the battery cell 20.

[0229] Of course, the thickness of the thickened part 212b2 meets the above conditions. On the one hand, it can ensure that the area of ​​the second part 212c2 close to the first part 212c1 has sufficient blocking performance. On the other hand, it can also ensure that the thickness of the area of ​​the second part 212c2 close to the first part 212c1 is not too large and thus have a negative impact on the energy density of the battery cell 20.

[0230] In some embodiments of this application, the thickened portion 212b2 is provided around the body portion 212b1. That is, the entire circumferential edge of the second portion 212c2 is the thickened portion 212b2, and the annular thickened portion 212b2 can be connected to the first portion 212c1 around its circumference. The circumferential sealing of the connection area between the end cap 212a and the housing 211 is improved, and the risk of the end cap 212a being corroded by the electrolyte is also reduced.

[0231] The thickened portion 212b2 can improve the blocking performance of the entire circumferential area of ​​the second portion 212c2, further isolate the third side 101c from the electrolyte, reduce the probability of the electrolyte coming into contact with the third side 101c, and thus reduce the risk of the end cap 212a being corroded by the electrolyte.

[0232] In some embodiments of this application, as shown in Figures 10-13, the end cap 212a also has a second side surface 102, and the first side surface 101 and the second side surface 102 are disposed opposite to each other along the thickness direction of the end cap 212a.

[0233] The end cap 212a also has a first outer peripheral surface 103, which can connect the first side surface 101 and the second side surface 102 together.

[0234] In some embodiments of this application, at least a portion of the edge region of the third side 101c is constructed as a guide slope 108, that is, the guide slope 108 is not on the same plane as other regions on the third side 101c, nor is the guide slope 108 parallel to other regions on the third side 101c, but rather the guide slope 108 is inclined relative to other regions on the third side 101c.

[0235] Therefore, when the end cap assembly 212 is located below the battery cell 20, and the battery cell 20 is heated, the blocking material initially located on the third side 101c melts. The molten blocking material on the third side 101c can flow downward through the guide slope 108 under the action of gravity and move between the first connecting surface M1 and the second connecting surface M2.

[0236] For example, the guide slope 108 has a first end away from the first outer peripheral surface 103 and a second end close to the first outer peripheral surface 103. If the second side surface 102 is a relatively flat plane, the distance between the guide slope 108 and the second side surface 102 gradually decreases from the first end to the second end.

[0237] In some embodiments of this application, the guide slope 108 can be a plane or an arc surface, as long as the distance between the guide slope 108 and the second side surface 102 gradually decreases from the first end to the second end.

[0238] In some embodiments of this application, the angle between the guide slope 108 and the first outer peripheral surface 103 is an obtuse angle, that is, the guide slope 108 is inclined toward the second side surface 102.

[0239] In the above scheme, on the one hand, it ensures that the molten blocking material can flow relatively smoothly, so that the blocking component 212b can flow more stably between the first connecting surface M1 and the second connecting surface M2, and can better seal the gap between the first connecting surface M1 and the second connecting surface M2. On the other hand, it ensures that the molten blocking material has a sufficient flow speed, thereby improving the efficiency of the blocking component 212b flowing between the first connecting surface M1 and the second connecting surface M2.

[0240] It should be noted that in the embodiment where the first outer peripheral surface 103 of the end cap 212a is configured as the first connecting surface M1 and is connected to a portion of the inner peripheral surface 107 of the housing 211 to form a connecting portion 211c, the molten blocking material on the third side surface 101c can flow to the first connecting surface M1 and the second connecting surface M2 through the guide slope 108; in the embodiment where the end surface 105 of the housing 211 is configured as the second connecting surface M2 and a portion of the first side surface 101 is the first connecting surface M1 that cooperates with the second connecting surface M2, in the embodiment where the end cap 212a is connected to the end surface 105 of the housing 211, at least a portion of the first side surface 101 protrudes toward the interior of the battery cell 20 to form a protrusion 212a1, and the guide slope 108 can be the peripheral surface of the protrusion 212a1.

[0241] In some embodiments of this application, as shown in FIG10, the guide ramp 108 may be arranged around the end cap 212a to form an annular region. Therefore, when the battery cell 20 is heated, the blocking material initially located on the third side 101c can move more evenly between the first connecting surface M1 and the second connecting surface M2, thereby forming the blocking member 212b of this application and improving the sealing performance between the end cap 212a and the housing 20.

[0242] The guide slope 108 can surround the coating area 101b and can further reduce the material of the end cap 212a, thereby reducing the manufacturing cost of the end cap 212a.

[0243] According to some embodiments of this application, as shown in Figures 11 and 13, a first groove 104a is provided on the edge region of the third side surface 101c. One end of the first groove 104a extends to the first connecting surface M1, and at least a portion of the bottom surface of the first groove 104a is constructed as a guide slope 108. That is, the edge region of the third side surface 101c is not entirely made into an inclined slope, but a portion of the edge region of the third side surface 101c is recessed toward the second side surface 102, thereby forming the first groove 104a.

[0244] The first groove 104a can guide the molten blocking material on the third side 101c into the space between the first connecting surface M1 and the second connecting surface M2. The first groove 104a can store a certain amount of molten blocking material. Therefore, the area of ​​the blocked material coated on the inner circumferential surface 107 of the shell 211, which is directly opposite the first groove 104a, is larger than the height of the blocking material coated on other areas of the inner circumferential surface 107, thereby improving the sealing effect between the end cap 212a and the shell 211 to at least a certain extent.

[0245] It is understood that the area on the inner circumferential surface of the housing 211 that is not directly opposite the first groove 104a has a gap between it and the end cap 212a that communicates with the first groove 104a. The molten material flowing out from the first groove 104a coats the area on the inner circumferential surface 107 of the housing 211 that is not directly opposite the first groove 104a through this gap.

[0246] Since the edge region of the third side 101c is not entirely sloping, the flow of molten material is more concentrated, and the molten material can more easily reach the area between the first connecting surface M1 and the second connecting surface M2 through the first groove 104a. This reduces the likelihood that the molten material would not easily flow between the first connecting surface M1 and the second connecting surface M2 due to the overall large size of the edge region of the third side 101c.

[0247] Providing a first groove 104a in the edge region of the first side 101 can also significantly reduce the material used in the end cap 212a and reduce the manufacturing cost of the end cap 212a.

[0248] According to some embodiments of this application, as shown in Figures 10-11, there are multiple first grooves 104a, which are spaced apart circumferentially along the end cap 212a. Therefore, after the material melts, the molten material on the coating area 101c can flow uniformly between the first connecting surface M1 and the second connecting surface M2, improving the sealing uniformity between the end cap 212a and the inner circumferential surface 107 of the housing 211.

[0249] Of course, by providing multiple first grooves 104a on the edge region of the first side 101, the material used in the end cap 212a can be further reduced, thereby reducing the manufacturing cost of the end cap 212a.

[0250] In some embodiments of this application, as shown in Figures 11 and 13, a second groove 104b is provided on the third side 101c, and the end of the first groove 104a away from the first connecting surface M1 communicates with the second groove 104b. The initial blocking material can be stored in the second groove 104b, and the thickness of the blocking material in the second groove 104b is greater than the thickness of the blocking material in other areas of the third side 101c. Therefore, after the battery cell 20 is heated, the amount of material after the blocking material in the second groove 104b melts can support its flow between the first connecting surface M1 and the second connecting surface M2, ensuring good sealing performance between the end cap 212a and the housing 211.

[0251] Of course, by setting the second groove 104b, the material used in the end cap 212a can be further reduced, thereby reducing the manufacturing cost of the end cap 212a.

[0252] In some embodiments of this application, as shown in Figures 11 and 13, the bottom surface of the first groove 104a connects the bottom surface of the second groove 104b and the first connecting surface M1. Thus, the portion of the initial blocking material located within the second groove 104b can easily flow through the bottom surface of the first groove 104a and reach between the first connecting surface M1 and the second connecting surface M2 after the battery cell 20 is heated and melted.

[0253] The molten blocking material can flow from the first side 101 to the inner peripheral surface 107 of the shell 211, and the molten blocking material can even flow between the first connecting surface M1 and the second connecting surface M2.

[0254] According to some embodiments of this application, as shown in Figures 10-11, the second groove 104b is an annular groove extending circumferentially along the third side surface. Thus, the portion of the initial blocking material within the second groove 104b can have sufficient material quantity after melting, allowing it to flow circumferentially between the first connecting surface M1 and the second connecting surface M2, thereby further improving the sealing performance between the end cap 212a and the housing 211.

[0255] In some embodiments of this application, as shown in FIG13, the included angle between the guide slope 108 and the first connecting surface M1 is α, which satisfies: 110°≤α≤170°. For example, α can be 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165° or 170°.

[0256] The values ​​of α mentioned above are just some specific examples of embodiments of this application. As long as the included angle between the guide slope 108 and the first connecting surface M1 meets the above range, it is within the protection scope of this application.

[0257] Since the angle between the guide slope 108 and the first connecting surface M1 meets the above range, on the one hand, the initial blocking material on the third side surface 101c can flow more easily to the space between the first connecting surface M1 and the second connecting surface M2 after melting. On the other hand, the tilt angle of the guide slope 108 is not too large, which would result in poor structural strength of the outer periphery of the end cap 212a.

[0258] Of course, the included angle between the guide slope 108 and the first connecting surface M1 satisfies the above range, which can also reduce the weight of the end cover 212a and the manufacturing cost of the end cover 212a.

[0259] The battery 100 of this application embodiment is briefly described below.

[0260] The battery 100 according to an embodiment of this application includes the aforementioned battery cell 20. Because the battery 100 according to an embodiment of this application is provided with the aforementioned battery cell 20, the end cap 212a of the battery 100 has stronger corrosion resistance, effectively reducing the risk of the end cap 212a being corroded by the electrolyte, and also reducing the risk of electrolyte leakage from the battery 100.

[0261] According to some embodiments of this application, the end cap 212a is located below the housing 211 along the direction of gravity. Therefore, when the battery cell 20 is inverted and subjected to high-temperature baking, the molten blocking material can flow under gravity to the side of the connection portion 211c facing the inside of the battery cell 20, thereby reducing the probability of the electrolyte contacting the connection portion 211c.

[0262] The electrical equipment of the present application embodiment is briefly described below.

[0263] The electrical device according to the embodiments of this application includes the battery cell 20 of the above embodiments or the battery 100 of the above embodiments. Since the electrical device according to the embodiments of this application is provided with the above-mentioned battery cell 20 or battery, the power supply stability of the electrical device is improved.

[0264] As shown in Figure 28, the manufacturing method of the battery cell 20 according to an embodiment of this application will be described in detail below.

[0265] It should be noted that the initial blocking material in the embodiments of this application refers to the unmelted blocking member 212b shown in Figures 4-5.

[0266] S1: An end cap assembly 212 is provided, comprising an end cap 212a and an initial stop 212b. The stop 212b is located on one side of the end cap 212a in the thickness direction. As shown in Figures 4-5, the end cap 212a has a first side 101 and a second side 102, which are disposed opposite to each other along the thickness direction of the end cap 212a. The end cap 212a also has a first outer peripheral surface 103, which can connect the first side 101 and the second side 102 together. The initial stop 212b can be disposed on the first side 101.

[0267] It should be noted that the initial blocking element 212b in the end cap assembly 212 can melt after the battery cell 20 is heated.

[0268] S2: Provide a housing 211 having a first opening.

[0269] S3: Provide electrode assembly 22 and install electrode assembly 22 into housing 211.

[0270] Of course, the electrode assembly 22 can enter the interior of the housing 211 through the first opening. Electrolyte can also be injected into the interior of the housing 211 before or after this step.

[0271] S4: Cover the end cap assembly 212 over the first opening 106, so that the initial blocking member 212b faces the inside of the housing 211;

[0272] S5: Connect end cap 212a and housing 211 to form an assembly.

[0273] Alternatively, the end cap 212a and the housing 211 can be fixed together by welding. The weld (i.e., the connection 211c) between the end cap 212a and the housing 211 can be located on the outer side of the part between the end cap 212a and the housing 211.

[0274] S6: Heat the assembly to melt the initial blocking element 212b and connect the end cap 212a and the housing 211.

[0275] Therefore, the blocking element 212b can at least partially enter between the end cap 212a and the housing 211, blocking the electrolyte to a certain extent and reducing the probability of the electrolyte contacting the connection part 211c. The end cap 212a and the housing 211 can be sealed not only through their fixed connection area, but also through the blocking element 212b.

[0276] S7: Cool the assembly to allow the blocking component 212b to solidify.

[0277] As the temperature decreases, the molten blocking material hardens and solidifies to form a blocking component 212b. The blocking component 212b, which flows between the end cap 212a and the housing 211, seals the gap between the end cap 212a and the inner circumferential surface of the housing 211, preventing the electrolyte from contacting the connection part 211c.

[0278] S8: Inject electrolyte into the housing 211.

[0279] According to the manufacturing method of the battery cell 20 in the embodiments of this application, the electrode assembly 22 can be installed inside the housing 211. By heating the assembly, the molten blocking member 212b flows to the space between the end cap 212a and the housing 211, thereby blocking the electrolyte to a certain extent and reducing the probability of contact between the electrolyte and the connection part 211c, thereby reducing the occurrence of leakage of the battery cell 20.

[0280] In addition, the cured blocking member 212b can completely cover the third side 101c, so that even if the end cap assembly 212 is located below the battery cell 20, the third side 101c will not come into contact with the electrolyte, thereby reducing the risk of the end cap 212a being corroded by the electrolyte.

[0281] After the end cap assembly 212 and the housing 211 are assembled together to form an assembly, the assembly is heated. At this time, the initial blocking material melts, and the molten blocking material can diffuse between the first connecting surface M1 and the second connecting surface M2. Thus, not only can the end cap 212a and the housing 211 be sealed once through the fixed connection area, but the solidified blocking material can also extend to the space between the first connecting surface M1 and the second connecting surface M2. This reduces the probability of electrolyte contact with the connection part 211c, lowers the possibility of corrosion of the connection part 211c, and provides a secondary seal between the end cap 212a and the housing 211. This further improves the sealing performance of the battery cell 20, further reduces the risk of electrolyte leakage in the battery cell 20, and improves the reliability of the battery cell.

[0282] In some embodiments of this application, the end cap assembly 212 faces downwards when the assembly is heated. As a result, the molten blocking material on the third side 101c can flow towards the space between the end cap 212a and the housing 211 under the influence of gravity. Thus, the initial blocking material can diffuse between the end cap 212a and the housing 211 after cooling, thereby blocking the electrolyte to at least a certain extent, reducing the probability of contact between the electrolyte and the connection 211c, and thus reducing the occurrence of leakage from the battery cell 20.

[0283] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The casing has a first opening; An end cap covers the first opening, and the end cap and the housing are sealed together to form a connection. Electrolyte is disposed inside the housing; Electrode assembly, disposed within the housing; A blocking element connects the end cap and the housing, and is located on the side of the connection portion facing the inside of the battery cell.

2. The battery cell according to claim 1, characterized in that, The end cap has a first connecting surface, the housing has a second connecting surface, the first connecting surface and the second connecting surface are disposed opposite to each other and connected to form the connecting portion, and at least a portion of the blocking member is disposed between the first connecting surface and the second connecting surface.

3. The battery cell according to claim 2, characterized in that, The portion of the blocking member disposed between the first connecting surface and the second connecting surface is an annular structure extending circumferentially along the end cap.

4. The battery cell according to claim 2 or 3, characterized in that, The end cap has a first side facing the interior of the battery cell and a second side facing away from the interior of the battery cell, and a first outer peripheral surface connecting the first side and the second side, wherein the first connecting surface is the first outer peripheral surface; the housing has an inner peripheral surface facing the interior of the battery cell, and a portion of the inner peripheral surface forms the second connecting surface.

5. The battery cell according to claim 2 or 3, characterized in that, The housing has a second outer peripheral surface facing away from the interior of the battery cell and an inner peripheral surface facing the interior of the battery cell, and an end face connecting the inner peripheral surface and the second outer peripheral surface, wherein the second connecting surface is the end face, and the end cap has a first side surface facing the interior of the battery cell, wherein a portion of the first side surface forms the first connecting surface.

6. The battery cell according to claim 5, characterized in that, The first side has a protrusion, and the first connecting surface is disposed around the protrusion.

7. The battery cell according to claim 6, characterized in that, A portion of the blocking member is disposed between the protrusion and the inner circumferential surface of the housing.

8. The battery cell according to any one of claims 1-7, characterized in that, The housing has an end face, and the end cap has a third side face facing the interior of the battery cell and offset from the end face along the thickness direction of the end cap. The first connecting surface is arranged around the third side face. The blocking member includes a first part and a second part connected to each other, the first part being disposed between the first connecting surface and the second connecting surface, and the second part covering at least a portion of the third side surface.

9. The battery cell according to claim 8, characterized in that, The blocking element covers the entire third side.

10. The battery cell according to claim 8 or 9, characterized in that, The second part includes a body portion and a thickened portion, the thickened portion surrounding the outer periphery of the body portion; Along the thickness direction of the end cap, the maximum thickness of the thickened portion is greater than the maximum thickness of the main body portion.

11. The battery cell according to claim 10, characterized in that, The thickened portion has a first side connected to the main body and a second side connected to the first portion, and the thickness of the thickened portion gradually increases from the first side to the second side.

12. The battery cell according to claim 10 or 11, characterized in that, The maximum thickness of the thickened portion is t, and it satisfies the following condition: 0mm < t ≤ 3mm.

13. The battery cell according to any one of claims 8-12, characterized in that, At least a portion of the edge region of the third side is constructed as a guide ramp.

14. The battery cell according to claim 13, characterized in that, The angle between the guide ramp and the first connecting surface is an obtuse angle.

15. The battery cell according to claim 13 or 14, characterized in that, The guide ramp is arranged around the end cap and forms an annular area.

16. The battery cell according to any one of claims 13-15, characterized in that, The edge region of the third side is provided with a first groove, one end of the first groove extends to the first connecting surface, and at least a portion of the bottom wall of the first groove is constructed as the guide slope.

17. The battery cell according to claim 16, characterized in that, There are multiple first grooves, and the multiple first grooves are arranged at intervals along the circumference of the end cap.

18. The battery cell according to claim 17, characterized in that, The third side surface is also provided with a second groove, which is located at the end of the first groove away from the first connecting surface and communicates with the first groove.

19. The battery cell according to claim 18, characterized in that, The second groove is an annular groove extending circumferentially along the third side surface.

20. The battery cell according to any one of claims 1-19, characterized in that, The melting point of the insulating layer is greater than or equal to 85°C and less than or equal to 120°C.

21. The battery cell according to any one of claims 1-20, characterized in that, The insulating layer comprises one or more of paraffin wax, rosin, PE wax, polyolefin, stearic acid, and white oil.

22. A battery, characterized in that, Includes the battery cell according to any one of claims 1-21.

23. The battery according to claim 22, characterized in that, The end cap is located below the housing along the direction of gravity.

24. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-21 or a battery according to claim 22 or 23, the battery being used to provide electrical energy.

25. A method for manufacturing a single battery cell, characterized in that, include: An end cap assembly is provided, the end cap including an end cap and a blocking member, the blocking member being disposed on one side of the end cap in the thickness direction; A housing is provided, the housing having a first opening; Provide an electrode assembly, and install the electrode assembly into the housing; The end cap assembly is placed over the first opening, with the blocking member facing the interior of the housing; The end cap and the housing are connected to form an assembly; The assembly is heated to melt the blocking element and connect the end cap and the housing; Cool the assembly to solidify the blocking component; Electrolyte is injected into the housing.

26. The method for manufacturing a single battery cell according to claim 25, characterized in that, When the assembly is heated, the end cap assembly is oriented downwards.

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