Battery cell, battery apparatus, and electrical apparatus

Abstract

Embodiments of the present application provide a battery cell, a battery apparatus, and an electrical apparatus. The battery cell comprises a casing, a pressure relief mechanism, an electrode assembly, and a first insulating member. The casing comprises a first wall. The pressure relief mechanism is disposed on the first wall. The electrode assembly is disposed within the housing. The first insulating member is disposed between the electrode assembly and the first wall. The melting point of the first insulating member is greater than 250°C, and on the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first insulating member at least partially overlaps the orthographic projection of the pressure relief mechanism. According to the technical solution provided in the present application, the reliability of the battery apparatus can be improved.

Description

Battery cells, battery packs and electrical devices Cross-references to related applications

[0001] This application claims priority to Chinese patent application CN202422507403.7, filed on October 16, 2024, entitled “Battery cell, battery device and power consumption device”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery device technology, and more specifically, to a battery cell, a battery device, and an electrical device. Background Technology

[0003] 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.

[0004] In the manufacturing process of battery devices, the reliability of the battery is a crucial issue. Therefore, improving battery reliability is a pressing technical problem that needs to be solved in battery device technology. Summary of the Invention

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

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

[0007] In a first aspect, embodiments of this application provide a battery cell, which includes a casing, a pressure relief mechanism, an electrode assembly, and a first insulating member. The casing includes a first wall; the pressure relief mechanism is disposed on the first wall; the electrode assembly is disposed within the casing; and the first insulating member is disposed between the electrode assembly and the first wall. The first insulating member has a melting point greater than 250°C, and on the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first insulating member at least partially overlaps with the orthographic projection of the pressure relief mechanism.

[0008] According to the battery cell of the present application embodiment, when the battery cell constitutes a battery device, since the melting point of the first insulating member is greater than 250°C, the first insulating member is not easily melted when the battery cell experiences thermal runaway. The first insulating member can separate the electrode assembly and the first wall that provides the pressure relief mechanism. At the same time, the first insulating member and the pressure relief mechanism have an overlapping area. The first insulating member can block at least part of the pressure relief port of the pressure relief mechanism to block the particles inside the battery cell, reduce the risk that the particles inside the battery cell will be directly ejected from the pressure relief port and damage other components inside the battery device, thereby improving the reliability of the battery device constituted by the battery cell.

[0009] According to some embodiments of this application, a gap exists between the first insulating member and the pressure relief mechanism along the thickness direction of the first wall.

[0010] In the above scheme, the first insulating component and the pressure relief mechanism are spaced apart to facilitate the pressure relief mechanism to release pressure and reduce the influence of the first insulating component on the pressure relief mechanism. For example, when a battery cell experiences thermal runaway, the pressure relief mechanism forms a pressure relief port, and the airflow inside the casing can flow to the pressure relief port through the gap between the first insulating component and the pressure relief mechanism.

[0011] According to some embodiments of this application, the battery cell further includes a first adhesive layer, and the first insulating member is bonded to the first wall through the first adhesive layer. The first insulating member includes an adhesive area with the first adhesive layer and a non-adhesive area without the first adhesive layer. On the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the non-adhesive area and the orthographic projection of the pressure relief mechanism at least partially overlap, and there is a gap between the non-adhesive area and the pressure relief mechanism.

[0012] In the above scheme, the first insulating component is bonded to the first wall by the first adhesive layer, which is simple in process, convenient in operation, and facilitates the assembly of the first insulating component and the first wall. The orthographic projection of the non-adhesive area and the orthographic projection of the pressure relief mechanism overlap at least partially. That is, at least part of the overlapping area between the first insulating component and the pressure relief mechanism is not provided with the first adhesive layer, so that there is a gap between the non-adhesive area and the pressure relief mechanism, which facilitates the airflow from the gap to the pressure relief port of the pressure relief mechanism.

[0013] According to some embodiments of this application, the thickness of the first adhesive layer is greater than or equal to 3 μm and less than or equal to 100 μm.

[0014] In the above scheme, the thickness of the first adhesive layer satisfies the above relationship. While meeting the connection requirements between the first insulating component and the first wall, a gap of a certain size is formed between the first insulating component and the pressure relief mechanism. At the same time, the structure formed by the first insulating component and the first adhesive layer occupies a small assembly space in the thickness direction of the first wall.

[0015] According to some embodiments of this application, the first adhesive layer includes a first sub-adhesive layer and a second sub-adhesive layer, the adhesive region includes a first adhesive region provided with the first sub-adhesive layer and a second adhesive region provided with the second sub-adhesive layer, the first adhesive region and the second adhesive region are spaced apart along a first direction, and the non-adhesive region is located between the first adhesive region and the second adhesive region, the first direction being perpendicular to the thickness direction of the first wall.

[0016] In the above scheme, the first adhesive region and the second adhesive region are spaced apart in the first direction. The first adhesive region is connected to the first wall through the first sub-adhesive layer, and the second adhesive region is connected to the first wall through the second sub-adhesive layer. The two areas of the first insulating member in the first direction are connected to the first wall, which facilitates the improvement of the connection stability between the first insulating member and the first wall. The non-adhesive region is located between the first adhesive region and the second adhesive region. A gap is reserved in the first direction for airflow to pass through, so that when the battery cell thermally runs away, the airflow in the casing flows from the gap between the non-adhesive region and the first wall to the pressure relief port of the pressure relief mechanism.

[0017] According to some embodiments of this application, the first direction is parallel to the length direction of the first wall.

[0018] In the above scheme, the first direction is parallel to the length direction of the first wall, and the first viscous region and the second viscous region are spaced apart in the length direction of the first wall. On the one hand, the first viscous region and the second viscous region can be set with a large size in the length direction of the first wall, which is convenient to increase the connection area between the first insulating component and the first wall and to improve the connection stability between the first insulating component and the first wall. On the other hand, the non-viscous region can also have a large size in the length direction of the first wall, which is convenient to increase the overlap area between the non-viscous region and the pressure relief mechanism, and to facilitate the airflow to the pressure relief port of the pressure relief mechanism.

[0019] According to some embodiments of this application, along the first direction, the minimum distance between the first sub-adhesive layer and the pressure relief mechanism is greater than or equal to 2 mm, and the minimum distance between the second sub-adhesive layer and the pressure relief mechanism is greater than or equal to 2 mm.

[0020] In the above scheme, the minimum distance between the first sub-adhesive layer and the pressure relief mechanism along the first direction and the minimum distance between the second sub-adhesive layer and the pressure relief mechanism along the first direction satisfy the above relationship. On the one hand, the adhesive application is less difficult and easier to assemble; on the other hand, the non-adhesive area has a larger size in the first direction, which makes it easier to increase the space between the first insulating component and the first wall, and facilitates the rapid flow of air to the pressure relief port of the pressure relief mechanism when the battery cell experiences thermal runaway.

[0021] According to some embodiments of this application, the first insulating element is a sheet structure, and the thickness of the first insulating element is greater than or equal to 7 μm and less than or equal to 400 μm.

[0022] In the above scheme, the thickness of the first insulating member satisfies the above relationship. While satisfying the condition that the first insulating member separates the electrode assembly from the first wall, the first insulating member occupies a small assembly space in the thickness direction of the first wall and can reduce material waste.

[0023] According to some embodiments of this application, in the width direction of the first wall, the dimension of the first wall is W1, and the dimension of the first insulating member is W2, satisfying that 0.5≤W2 / W1≤1.

[0024] In the above scheme, the width of the first wall and the dimension of the first insulating member in the width direction of the first wall satisfy the above relationship. Under the condition that the first insulating member and the first wall do not interfere with each other, the dimension of the first insulating member in the width direction of the first wall can be designed to be larger, so that the first insulating member and the electrode assembly have a large overlap area in the width direction of the first wall, which is beneficial to reduce the risk of short circuit between the electrode assembly and the first wall when the battery cell thermally runs away.

[0025] According to some embodiments of this application, the material of the first insulating element is polyimide, soluble polytetrafluoroethylene, polyaryletherketone, polyphenylene sulfide, tetrafluoroethylene-ethylene copolymer, perfluoroethylene propylene, or high-temperature resistant nylon.

[0026] In the above scheme, polyimide, soluble polytetrafluoroethylene, polyaryletherketone, polyphenylene sulfide, tetrafluoroethylene-ethylene copolymer, perfluoroethylene propylene, or high-temperature resistant nylon have good high-temperature resistance, so as to form a barrier between the electrode assembly and the first wall after the battery cell thermal runaway, thereby reducing the risk of the electrode assembly contacting the first wall when the battery cell thermal runaway occurs.

[0027] According to some embodiments of this application, the battery cell further includes a separator disposed between the electrode assembly and the first wall; a first insulating member is disposed between the separator and the first wall, and the melting point of the first insulating member is higher than that of the separator.

[0028] In the above scheme, the separator can separate the electrode assembly from the first wall, reducing the risk of short circuit between the positive and negative electrodes caused by the contact between the electrode assembly and the first wall. The melting point of the first insulating component is higher than that of the separator. In the event of thermal runaway of the battery cell, even if the separator melts, the first insulating component can still separate the electrode assembly from the first wall.

[0029] According to some embodiments of this application, the battery cell further includes a second insulating member and a third insulating member. The second insulating member encloses at least a portion of the electrode assembly. The third insulating member connects the separator and the second insulating member. At least a portion of the third insulating member is located between the electrode assembly and the first wall. The melting point of the third insulating member is higher than that of the separator.

[0030] In the above scheme, the second insulating member wraps at least a portion of the electrode assembly to reduce the risk of short circuit between the electrode assembly and the housing; compared with the insulating member, the third insulating member has a higher melting point, so that even if the insulating member melts, the third insulating member can still separate the electrode assembly from the first wall.

[0031] According to some embodiments of this application, the third insulating member includes a first part and a second part that are interconnected. The first part is located between the insulating member and the first wall and is connected to the insulating member. The second part is stacked with the second insulating member and is connected to the second insulating member.

[0032] In the above scheme, the first part is connected to the isolator, the second part passes over the isolator and connects to the second insulating part, and the third insulating part can provide a constraint force for the isolator, which facilitates the assembly of the isolator and the electrode assembly.

[0033] According to some embodiments of this application, on the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first portion does not overlap with the orthographic projection of the first insulating member.

[0034] In the above scheme, the orthographic projection of the first part does not overlap with the orthographic projection of the first insulating component, which facilitates the improvement of the space utilization rate inside the casing in the thickness direction of the first wall, so that the battery cell can have a higher energy density.

[0035] According to some embodiments of this application, the first portion is spaced apart from the first insulating element.

[0036] In the above scheme, the first part and the first insulating component are spaced apart to facilitate assembly and reduce the risk of interference between the first part and the first insulating component.

[0037] According to some embodiments of this application, the distance between the first part and the first insulating member is greater than or equal to 0.1 mm and less than or equal to 5 mm.

[0038] In the above scheme, the distance between the first part and the first insulating member satisfies the above relationship. Under the condition of low assembly difficulty, the first part and the first insulating member can have a large overlap area with the electrode assembly in the thickness direction of the first wall. This facilitates the separation of the electrode assembly and the first wall by the first part and the first insulating member in the event of thermal runaway of the battery cell, thereby reducing the risk of short circuit between the electrode assembly and the first wall.

[0039] According to some embodiments of this application, the battery cell further includes a second adhesive layer, the first part is bonded to the separator through the second adhesive layer, and the second part is bonded to the second insulating member through the second adhesive layer.

[0040] In the above solution, the first part is bonded to the separator through the second adhesive layer, which is convenient to operate and facilitates the assembly of the first part and the separator; the second part is bonded to the second insulating part through the second adhesive layer, which makes the connection between the second part and the second insulating part firm and facilitates the assembly of the second part and the second insulating part.

[0041] According to some embodiments of this application, the thickness of the third insulating element is greater than or equal to 7 μm and less than or equal to 150 μm.

[0042] In the above scheme, the thickness of the third insulating component satisfies the above relationship. While satisfying the requirement that the third insulating component separates the electrode assembly from the housing, the third insulating component occupies less assembly space and can reduce material waste.

[0043] According to some embodiments of this application, the thickness of the second adhesive layer is greater than or equal to 3 μm and less than or equal to 50 μm.

[0044] In the above scheme, the thickness of the second adhesive layer satisfies the above relationship, which can meet the connection requirements between the third insulating component and the isolation component and the second insulating component, and the structure after the third insulating component is connected to the isolation component and the second insulating component occupies a small assembly space.

[0045] According to some embodiments of this application, in the width direction of the first wall, the dimension of the first wall is W1, and the dimension of the third insulating member is W3, satisfying that 0.5≤W3 / W1≤0.9.

[0046] In the above scheme, the width of the first wall and the dimension of the third insulating member in the width direction of the first wall satisfy the above relationship. Under the condition that the third insulating member does not interfere with the first wall, the dimension of the third insulating member in the width direction of the first wall can be designed to be larger, so that the third insulating member and the electrode assembly have a large overlap area in the width direction of the first wall, which is beneficial to reduce the risk of short circuit between the electrode assembly and the first wall when the battery cell thermally runs away.

[0047] According to some embodiments of this application, the battery cell further includes electrode terminals, the housing includes a shell and an end cap, the shell has an opening, the end cap covers the opening, and the electrode terminals are disposed on the end cap; the shell includes a bottom wall and a side wall, the side wall surrounds the bottom wall, one end of the side wall is connected to the bottom wall, the other end of the side wall is connected to the end cap, and the bottom wall is a first wall.

[0048] In the above scheme, the pressure relief mechanism and the electrode terminals are arranged opposite to each other in the thickness direction of the first wall, which can reduce the impact of the pressure relief mechanism on other components inside the battery device when it releases the emissions from the battery cells, thus making the battery device more reliable.

[0049] Secondly, embodiments of this application also provide a battery device, which includes a battery cell provided according to any of the above embodiments.

[0050] Thirdly, embodiments of this application also provide an electrical device, which includes a battery device according to any of the above embodiments, the battery device being used to provide electrical energy.

[0051] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0052] 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.

[0053] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0054] Figure 2 is an exploded view of the structure of a battery device 100 provided in some embodiments of this application;

[0055] Figure 3 is an exploded view of the structure of a battery cell provided in some embodiments of this application;

[0056] Figure 4 is a schematic diagram of the first wall of a battery cell provided in some embodiments of this application;

[0057] Figure 5 is a cross-sectional view of a partial structure of a battery cell provided in some embodiments of this application;

[0058] Figure 6 is a schematic diagram of the structure of a battery cell provided in some other embodiments of this application;

[0059] Figure 7 is a cross-sectional view of a partial structure of a battery cell provided in some other embodiments of this application;

[0060] Figure 8 is a schematic diagram of the structure of the second insulating member and the first insulating member of a battery cell provided in some other embodiments of this application;

[0061] Figure 9 is a magnified view of part A in Figure 7.

[0062] The accompanying drawings are not drawn to scale.

[0063] Marking Explanation: 100-Battery Unit; 10-Casing; 11-First Sub-Casing; 12-Second Sub-Casing; 20-Battery Cell; 21-Outer Shell; 211-First Wall; 212-Shell; 212a-Bottom Wall; 212b-Side Wall; 213-End Cap; 22-Pressure Relief Mechanism; 23-Electrode Assembly; 24-First Insulator; 241-Adhesive Area; 242-Non-Adhesive Area; 25-First Adhesive Layer; 251-First Sub-Adhesive Layer; 252-Second Sub-Adhesive Layer; 26-Separator; 27-Second Insulator; 28-Third Insulator; 281-First Part; 282-Second Part; 29-Second Adhesive Layer; 30-Electrode Terminal; 200-Controller; 300-Motor; 1000-Vehicle; X-First Direction; Y-Width Direction of First Wall; Z-Thickness Direction of First Wall. Detailed Implementation

[0064] 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.

[0065] 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 foregoing drawings of this application are intended to cover non-exclusive inclusion.

[0066] The terms "first," "second," etc., in the specification, claims, or the accompanying drawings are used to distinguish different objects, not to describe a specific order or primary / secondary relationship.

[0067] 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 throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. 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.

[0068] 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.

[0069] 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 three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0070] 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).

[0071] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0072] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0073] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0074] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0075] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0076] As an example, the enclosure may include a first sub-enclosure and a second sub-enclosure. The first and second sub-enclosures are interlocked to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or shutting down; it can be sealed or not sealed. The first sub-enclosure may be a top cover or a bottom plate.

[0077] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0078] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0079] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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 made of stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium with a silver-plated surface. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector 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.).

[0086] 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.

[0087] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] In some embodiments, the isolation component is an isolation membrane. This application does not impose any particular limitation on the type of isolation membrane; any known porous isolation membrane with good chemical and mechanical stability can be selected.

[0092] 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 component 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.

[0093] In some embodiments, the isolation component 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.

[0094] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0095] In some implementations, the electrode assembly is a stacked structure.

[0096] 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), or a composite metal (such as a copper-aluminum composite housing).

[0097] 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.

[0098] 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.

[0099] In some embodiments, a pressure relief mechanism is provided on the casing. The pressure relief mechanism is used to release the internal pressure of the battery cells.

[0100] As an example, a 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.

[0101] The development of battery device technology must take into account multiple design factors, such as performance parameters like energy density, discharge capacity, and charge / discharge rate. In addition, the reliability of the battery device also needs to be considered.

[0102] In some embodiments, the battery device includes multiple battery cells, each including a housing and an electrode assembly disposed within the housing. Typically, a pressure relief mechanism is provided on the housing of the battery cell. When the battery cell experiences thermal runaway, the pressure relief mechanism actuates to discharge effluent from inside the battery cell to relieve internal pressure. The effluent exhibits high temperature and pressure, and particles in the effluent (such as metal particles, active material particles, etc.) can damage other components within the battery device, resulting in lower reliability.

[0103] In view of this, this application provides a battery cell including a casing, a pressure relief mechanism, an electrode assembly, and a first insulating member. The casing includes a first wall; the pressure relief mechanism is disposed on the first wall; the electrode assembly is disposed within the casing; and the first insulating member is disposed between the electrode assembly and the first wall. The first insulating member has a melting point greater than 250°C, and on the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first insulating member at least partially overlaps with the orthographic projection of the pressure relief mechanism. This battery cell, constituting a battery device, has high reliability.

[0104] When the battery cell is used to form a battery device, since the melting point of the first insulating component is greater than 250°C, the first insulating component is not easily melted when the battery cell experiences thermal runaway. The first insulating component can separate the electrode assembly and the first wall that provides the pressure relief mechanism. At the same time, the first insulating component and the pressure relief mechanism have an overlapping area. The first insulating component can block at least part of the pressure relief port of the pressure relief mechanism to block the particles inside the battery cell. This reduces the risk that particles inside the battery cell will be directly ejected from the pressure relief port and damage other components inside the battery device, thereby improving the reliability of the battery device formed by the battery cell.

[0105] The battery device disclosed in this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using the battery device disclosed in this application.

[0106] The technical solutions described in the embodiments of this application are applicable to various power devices that use battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0107] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0108] Please refer to Figure 1, which is a schematic diagram of the vehicle structure provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000. For example, the battery device 100 can serve as the operating power source for the vehicle 1000's electrical system, such as meeting the power requirements for starting, navigation, and operation of the vehicle 1000.

[0109] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0110] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0111] Please refer to Figure 2, which is an exploded view of the structure of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for accommodating the battery cell 20, and the housing 10 can adopt various structures. In some embodiments, the housing 10 may include a first sub-housing 11 and a second sub-housing 12, which overlap each other, and together define a space for accommodating the battery cell 20. The second sub-box 12 can be a hollow structure with one end open, and the first sub-box 11 can be a plate-like structure. The first sub-box 11 covers the opening side of the second sub-box 12 so that the first sub-box 11 and the second sub-box 12 together define the accommodating space. Alternatively, the first sub-box 11 and the second sub-box 12 can both be hollow structures with one side open, and the opening side of the first sub-box 11 covers the opening side of the second sub-box 12.

[0112] In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel connections. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is also housed within the housing 10. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0113] Please refer to Figure 3, which is an exploded view of the battery cell structure provided in some embodiments of this application; Figure 4 is a schematic diagram of the first wall of the battery cell provided in some embodiments of this application, and is a schematic diagram of the battery cell viewed along the thickness direction of the first wall, with the internal structure of the battery cell represented by dashed lines; Figure 5 is a cross-sectional view of a portion of the structure of the battery cell provided in some embodiments of this application, showing an assembly schematic diagram of the first insulating member and the pressure relief mechanism. This application provides a battery cell 20, which includes a housing 21, a pressure relief mechanism 22, an electrode assembly 23, and a first insulating member 24. The housing 21 includes a first wall 211; the pressure relief mechanism 22 is disposed on the first wall 211; the electrode assembly 23 is disposed within the housing 21; and the first insulating member 24 is disposed between the electrode assembly 23 and the first wall 211. The first insulating member 24 has a melting point greater than 250°C, and on the same projection plane perpendicular to the thickness direction Z of the first wall, the orthographic projection of the first insulating member 24 at least partially overlaps with the orthographic projection of the pressure relief mechanism 22.

[0114] The housing 21 includes a housing 212 and an end cap 213. The housing 212 has an opening, and the end cap 213 closes the opening to isolate the internal environment of the battery cell 20 from the external environment. The housing 212 and the end cap 213 form a receiving cavity in which the electrode assembly 23 is received.

[0115] The housing 212 is a component used to cooperate with the end cap 213 to form the internal environment of the battery cell 20, wherein the formed internal environment can accommodate the electrode assembly 23, electrolyte, and other components. The housing 212 and the end cap 213 can be independent components. The housing 212 can have various shapes and sizes. Specifically, the shape of the housing 212 can be determined according to the specific shape and size of the electrode assembly 23. The housing 212 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0116] End cap 213 refers to a component that covers the opening of housing 212 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 213 can be adapted to the shape of housing 212 to fit it. Optionally, end cap 213 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 213 is not easily deformed under pressure and impact, allowing battery cell 20 to have higher structural strength and improved reliability. Functional components such as electrode terminals can be provided on end cap 213. Electrode terminals can be used for electrical connection with electrode assembly 23 to output or input electrical energy to battery cell 20. The material of end cap 213 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this application embodiment does not impose special limitations on this. In some embodiments, an insulating structure can also be provided on the inner side of end cap 213. The insulating structure can be used to isolate the electrical connection components inside housing 212 from end cap 213 to reduce the risk of short circuit. For example, the insulating structure can be made of plastic, rubber, etc.

[0117] In some embodiments, the first wall 211 may be a wall portion of the housing 212. For example, the housing 212 includes a bottom wall and a side wall, the side wall surrounding the bottom wall, one end of the side wall being connected to the bottom wall, and the other end of the side wall forming an opening, the bottom wall being the first wall 211.

[0118] The pressure relief mechanism 22 refers to the element or component that is activated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold. The pressure relief mechanism 22 can take the form of an explosion-proof valve, a gas valve, a pressure relief valve, or a safety valve, and can specifically adopt a pressure-sensitive or temperature-sensitive element or structure. That is, when the internal pressure or temperature of the battery cell 20 reaches the predetermined threshold, the pressure relief mechanism 22 performs an action or a weak structure provided in the pressure relief mechanism 22 is destroyed, thereby forming an opening or channel for the release of internal pressure or temperature.

[0119] The term "actuation" as used in this application refers to the pressure relief mechanism 22 being activated or undergoing a certain state, thereby releasing the internal pressure and temperature of the battery cell 20. The actions of the pressure relief mechanism 22 may include, but are not limited to, at least a portion of the pressure relief mechanism 22 rupturing, breaking, tearing, or opening. When the pressure relief mechanism 22 is actuated, the high-temperature, high-pressure substances inside the battery cell 20 are discharged outwards from the actuated portion. This method allows for pressure and temperature relief of the battery cell under controllable pressure or temperature, thereby preventing potentially more serious accidents.

[0120] Electrode assembly 23 is the component in the battery cell 20 where the electrochemical reaction occurs. The housing 212 may contain one or more electrode assemblies 23. The electrode assembly 23 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 23, while the portions of the positive and negative electrode sheets without active material each constitute a tab.

[0121] In some embodiments, no other components may be provided between the electrode assembly 23 and the first insulating member 24, or other components may be provided between the electrode assembly 23 and the first insulating member 24, such as other insulating structures that wrap the electrode assembly 23, isolation structures that support the electrode assembly 23, etc.

[0122] In some embodiments, no other components may be provided between the first insulating member 24 and the first wall 211, or other components may be provided between the first insulating member 24 and the first wall 211, such as an isolation structure supporting the electrode assembly 23, a structure connecting the first insulating member 24 and the first wall 211, etc.

[0123] The first insulating element 24 has a melting point greater than 250°C. When the battery cell 20 experiences thermal runaway, the first insulating element 24 is less likely to melt compared to other insulating structures, so that the first insulating element 24 can separate the electrode assembly 23 and the first wall 211.

[0124] The insulation performance of the first insulating component 24 can meet the requirement of 500V > 200MΩ.

[0125] On the same projection plane perpendicular to the thickness direction Z of the first wall, the orthographic projection of the first insulating member 24 can partially overlap with the orthographic projection of the pressure relief mechanism 22, or the orthographic projection of the first insulating member 24 can completely overlap with the orthographic projection of the pressure relief mechanism 22. This can be understood as, when viewed along the thickness direction Z of the first wall, the first insulating member 24 can overlap with at least a portion of the pressure relief mechanism 22.

[0126] According to the battery cell 20 of the present application embodiment, when the battery cell 20 constitutes the battery device 100, since the melting point of the first insulating member 24 is greater than 250°C, the first insulating member 24 is not easily melted when the battery cell 20 is thermally runaway. The first insulating member 24 can separate the electrode assembly 23 and the first wall 211 where the pressure relief mechanism 22 is provided. At the same time, the first insulating member 24 and the pressure relief mechanism 22 have an overlapping area. The first insulating member 24 can block at least part of the pressure relief port of the pressure relief mechanism 22 to block the particles inside the battery cell 20, reduce the risk that the particles inside the battery cell 20 will be directly ejected from the pressure relief port and damage other components inside the battery device 100, thereby improving the reliability of the battery device 100 constituted by the battery cell 20.

[0127] Referring to Figure 5, according to some embodiments of this application, there is a gap between the first insulating member 24 and the pressure relief mechanism 22 along the thickness direction Z of the first wall.

[0128] In some embodiments, other components may be provided between the first insulating member 24 and the first wall 211 to increase the distance between the first insulating member 24 and the first wall 211, so that a gap is formed between the inner surfaces of the first insulating member 24 and the first wall 211, thereby creating a gap between the first insulating member 24 and the pressure relief mechanism 22.

[0129] In some embodiments, the inner surface of the first wall 211 may be provided with a protrusion, and the first insulating member 24 overlaps with the protrusion so that there is a gap between the first insulating member 24 and the pressure relief mechanism 22.

[0130] In the above scheme, the first insulating member 24 and the pressure relief mechanism 22 are spaced apart to facilitate the pressure relief mechanism 22 to relieve pressure and reduce the influence of the first insulating member 24 on the pressure relief mechanism 22. For example, when the battery cell 20 thermally runs away, the pressure relief mechanism 22 forms a pressure relief port, and the airflow in the casing 21 can flow to the pressure relief port through the gap between the first insulating member 24 and the pressure relief mechanism 22.

[0131] According to some embodiments of this application, when the battery cell 20 experiences thermal runaway, a gap can also be formed between the first insulating member 24 and the pressure relief mechanism 22 along the thickness direction Z of the first wall. For example, a protrusion can be provided on the inner surface of the first wall 211, or other high-temperature resistant components can be provided between the first insulating member 24 and the inner surface of the first wall 211, so that when the pressure relief port of the pressure relief mechanism 22 releases the emissions from inside the battery cell 20, the first insulating member 24 will not block the pressure relief port, facilitating airflow from the gap between the first insulating member 24 and the pressure relief mechanism 22 to the pressure relief port. It should be noted that although the first insulating member 24 overlaps with the pressure relief mechanism 22 and can block particles in the emissions, the airflow discharged from the pressure relief port from the casing 21 may contain a small number of particles.

[0132] According to some embodiments of this application, the battery cell 20 further includes a first adhesive layer 25, and the first insulating member 24 is bonded to the first wall 211 through the first adhesive layer 25. The first insulating member 24 includes an adhesive region 241 with the first adhesive layer 25 and a non-adhesive region 242 without the first adhesive layer 25. On the same projection plane perpendicular to the thickness direction Z of the first wall, the orthographic projection of the non-adhesive region 242 at least partially overlaps with the orthographic projection of the pressure relief mechanism 22, and there is a gap between the non-adhesive region 242 and the pressure relief mechanism 22.

[0133] In some embodiments, the first adhesive layer 25 may be a pressure-sensitive adhesive layer.

[0134] The first adhesive layer 25 is disposed between the first insulating member 24 and the first wall 211, and the first adhesive layer 25 is used to connect the first insulating member 24 and the first wall 211.

[0135] The adhesive area 241 refers to the area of ​​the first insulating member 24 where the first adhesive layer 25 is provided. The surface of the adhesive area 241 facing the first wall 211 is bonded to the first wall 211 through the first adhesive layer 25.

[0136] The non-adhesive area 242 refers to the area of ​​the first insulating member 24 that is not provided with the first adhesive layer 25. The non-adhesive area 242 and the pressure relief mechanism 22 are spaced apart in the thickness direction Z of the first wall so that there is a gap between the non-adhesive area 242 and the pressure relief mechanism 22.

[0137] In the above scheme, the first insulating component 24 is bonded to the first wall 211 by the first adhesive layer 25. The process is simple and convenient, and it is easy to assemble the first insulating component 24 and the first wall 211. The orthographic projection of the non-adhesive area 242 overlaps with the orthographic projection of the pressure relief mechanism 22 at least partially. That is, at least part of the overlapping area of ​​the first insulating component 24 and the pressure relief mechanism 22 is not provided with the first adhesive layer 25, so that there is a gap between the non-adhesive area 242 and the pressure relief mechanism 22, which facilitates the airflow to flow from the gap to the pressure relief port of the pressure relief mechanism 22.

[0138] According to some embodiments of this application, the thickness of the first adhesive layer 25 is greater than or equal to 3 μm and less than or equal to 100 μm.

[0139] The thickness direction of the first adhesive layer 25 is parallel to the thickness direction Z of the first wall.

[0140] In some embodiments, the thickness of the first adhesive layer 25 can be, but is not limited to, any one value or a range between any two values ​​from 3μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, and 100μm.

[0141] Since the first insulating element 24 is bonded to the first wall 211 by the first adhesive layer 25, the thickness of the first adhesive layer 25 affects the size of the gap between the first insulating element 24 and the first wall 211. The greater the thickness of the first adhesive layer 25, the larger the gap between the first insulating element 24 and the first wall 211, and correspondingly, the bonding effect between the first insulating element 24 and the first wall 211 is improved to a certain extent. The more material in the first adhesive layer 25, the higher the cost.

[0142] In the above scheme, the thickness of the first adhesive layer 25 satisfies the above relationship. While meeting the connection requirements between the first insulating member 24 and the first wall 211, a gap of a certain size is formed between the first insulating member 24 and the pressure relief mechanism 22. At the same time, the structure formed by the first insulating member 24 and the first adhesive layer 25 occupies a small assembly space in the thickness direction Z of the first wall.

[0143] Referring to Figures 4 and 5, according to some embodiments of this application, the first adhesive layer 25 includes a first sub-adhesive layer 251 and a second sub-adhesive layer 252. The adhesive region 241 includes a first adhesive region 241 provided with the first sub-adhesive layer 251 and a second adhesive region 241 provided with the second sub-adhesive layer 252. The first adhesive region 241 and the second adhesive region 241 are spaced apart along a first direction X. The non-adhesive region 242 is located between the first adhesive region 241 and the second adhesive region 241. The first direction X is perpendicular to the thickness direction Z of the first wall.

[0144] In some embodiments, the first viscous region 241, the non-viscous region 242, and the second viscous region 241 are sequentially distributed in the first direction X, and the first viscous region 241 and the second viscous region 241 may be located at both ends of the first insulating member 24 in the first direction X.

[0145] The first direction X can be parallel to the length direction of the first wall 211, or the first direction X can also be parallel to the width direction Y of the first wall.

[0146] In the above scheme, the first adhesive region 241 and the second adhesive region 241 are spaced apart in the first direction X. The first adhesive region 241 is connected to the first wall 211 through the first sub-adhesive layer 251, and the second adhesive region 241 is connected to the first wall 211 through the second sub-adhesive layer 252. The two regions of the first insulating member 24 in the first direction X are connected to the first wall 211, which facilitates the connection stability between the first insulating member 24 and the first wall 211. The non-adhesive region 242 is located between the first adhesive region 241 and the second adhesive region 241. A gap is reserved in the first direction X for airflow to pass through, so that when the battery cell 20 thermally runs away, the airflow in the outer casing 21 flows from the gap between the non-adhesive region 242 and the first wall 211 to the pressure relief port of the pressure relief mechanism 22.

[0147] Please refer to Figure 4. According to some embodiments of this application, the first direction X is parallel to the length direction of the first wall 211.

[0148] In some embodiments, the first wall 211 may be cuboid, and the first wall 211 has a length direction and a width direction, and the first direction X is parallel to the length direction of the first wall 211.

[0149] In the above scheme, the first direction X is parallel to the length direction of the first wall 211, and the first viscous region 241 and the second viscous region 241 are spaced apart in the length direction of the first wall 211. On the one hand, the first viscous region 241 and the second viscous region 241 can be set with a large size in the length direction of the first wall 211, which is convenient to increase the connection area between the first insulating member 24 and the first wall 211, and to improve the connection stability between the first insulating member 24 and the first wall 211. On the other hand, the non-viscous region 242 can also have a large size in the length direction of the first wall 211, so as to increase the overlap area between the non-viscous region 241 and the pressure relief mechanism 22, and to facilitate the airflow to the pressure relief port of the pressure relief mechanism 22.

[0150] According to some embodiments of this application, along the first direction X, the minimum distance between the first sub-adhesive layer 251 and the pressure relief mechanism 22 is greater than or equal to 2 mm, and the minimum distance between the second sub-adhesive layer 252 and the pressure relief mechanism 22 is greater than or equal to 2 mm.

[0151] The minimum distance between the first sub-adhesive layer 251 and the pressure relief mechanism 22 along the first direction X can be the minimum distance between the edge of the first sub-adhesive layer 251 near the pressure relief mechanism 22 and the pressure relief mechanism 22 along the first direction X.

[0152] The minimum distance between the second sub-adhesive layer 252 and the pressure relief mechanism 22 along the first direction X can be the minimum distance between the edge of the second sub-adhesive layer 252 near the pressure relief mechanism 22 and the pressure relief mechanism 22 along the first direction X.

[0153] In the above scheme, the minimum distance between the first sub-adhesive layer 251 and the pressure relief mechanism 22 along the first direction X and the minimum distance between the second sub-adhesive layer and the pressure relief mechanism 22 along the first direction X satisfy the above relationship. On the one hand, the adhesive application is less difficult and easier to assemble; on the other hand, the non-adhesive area 242 has a larger size in the first direction X, which makes it easier to increase the space between the first insulating member 24 and the first wall 211, so that when the battery cell 20 thermally runs away, the airflow can quickly flow to the pressure relief port of the pressure relief mechanism 22.

[0154] It should be noted that, in order to ensure that the first sub-adhesive layer 251 and the second sub-adhesive layer 252 have a large size in the first direction X, the minimum distance between the first sub-adhesive layer 251 and the pressure relief mechanism 22, and the minimum distance between the second sub-adhesive layer 252 and the pressure relief mechanism 22, should not be too large. That is, the size of the non-adhesive region 242 in the first direction X should not be too large. For example, the size of the non-adhesive region 242 in the first direction X minus the size of the pressure relief mechanism 22 in the first direction X can not exceed 10 mm.

[0155] Please refer to Figures 3 and 5. According to some embodiments of this application, the first insulating member 24 is a sheet structure, and the thickness of the first insulating member 24 is greater than or equal to 7 μm and less than or equal to 400 μm.

[0156] The first insulating element 24 can be regarded as an insulating sheet, and the thickness direction of the first insulating element 24 can be parallel to the thickness direction Z of the first wall.

[0157] The thickness of the first insulating element 24 affects the separation effect between the electrode assembly 23 and the first wall 211.

[0158] The thickness of the first insulating element 24 can be any single value or a range between any two values ​​from 7μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, and 400μm.

[0159] In the above scheme, the thickness of the first insulating member 24 satisfies the above relationship. When the first insulating member 24 separates the electrode assembly 23 and the first wall 211, the first insulating member 24 occupies a small assembly space in the thickness direction Z of the first wall and can reduce material waste.

[0160] Please refer to Figure 4. According to some embodiments of this application, in the width direction Y of the first wall, the dimension of the first wall 211 is W1, and the dimension of the first insulating member 24 is W2, satisfying that 0.5≤W2 / W1≤1.

[0161] W1 can be the width of the first wall.

[0162] W2 / W1 can be expressed as the ratio between the dimension of the first insulating member 24 in the width direction Y of the first wall and the width of the first wall 211.

[0163] In some embodiments, W2 / W1 can be, but is not limited to, any one value among 0.5, 0.6, 0.7, 0.8, 0.9, and 1, or a range between any two point values.

[0164] In the above scheme, the width of the first wall 211 and the size of the first insulating member 24 in the width direction Y of the first wall satisfy the above relationship. Under the condition that the first insulating member 24 and the first wall 211 do not interfere, the size of the first insulating member 24 in the width direction Y of the first wall can be designed to be larger, so that the first insulating member 24 and the electrode assembly 23 have a larger overlap area in the width direction Y of the first wall, which is beneficial to reduce the risk of short circuit between the electrode assembly 23 and the first wall 211 when the battery cell 20 is thermally runaway.

[0165] According to some embodiments of this application, the material of the first insulating element 24 is polyimide, soluble polytetrafluoroethylene, polyaryletherketone, polyphenylene sulfide, tetrafluoroethylene-ethylene copolymer, perfluoroethylene propylene, or high-temperature resistant nylon.

[0166] Polyimide is an aromatic heterocyclic polymer compound whose molecular structure contains imide chain segments.

[0167] Polyaryletherketones are polymers whose main chain consists of phenylene rings linked by ether and ketone bonds. They can be classified into polyetheretherketone, polyetherketoneketone, polyetherketone, and polyetherketoneetherketoneketone according to the number and order of ether and ketone groups.

[0168] Soluble polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer, and perfluoroethylene propylene are fluorinated plastics, and materials with a melting point greater than 250℃ are selected.

[0169] In the above scheme, polyimide, soluble polytetrafluoroethylene, polyaryletherketone, polyphenylene sulfide, tetrafluoroethylene-ethylene copolymer, perfluoroethylene propylene, or high-temperature resistant nylon have good high-temperature resistance, so as to form a barrier between the electrode assembly 23 and the first wall 211 after the battery cell 20 thermally runs away, thereby reducing the risk of the electrode assembly 23 contacting the first wall 211 when the battery cell 20 thermally runs away.

[0170] Please refer to Figures 6 and 7. Figure 6 is a structural schematic diagram of a battery cell provided in some embodiments of this application, and Figure 7 is a cross-sectional view of a partial structure of a battery cell provided in some embodiments of this application. According to some embodiments of this application, the battery cell 20 further includes a separator 26, which is disposed between the electrode assembly 23 and the first wall 211; a first insulating member 24 is disposed between the separator 26 and the first wall 211, and the melting point of the first insulating member 24 is higher than that of the separator 26.

[0171] The isolator 26 is a component used to isolate the electrode assembly 23 from the first wall 211, and the isolator 26 can be an insulating component.

[0172] The melting point of the first insulating member 24 is higher than that of the separator 26. When the battery cell 20 experiences thermal runaway, the separator 26 melts before the first insulating member 24. The first insulating member 24 can separate the electrode assembly 23 from the first wall 211, thereby reducing the risk of short circuit between the electrode assembly 23 and the first wall 211.

[0173] In the above scheme, the separator 26 can separate the electrode assembly 23 from the first wall 211, reducing the risk of short circuit between the positive and negative electrodes caused by the contact between the electrode assembly 23 and the first wall 211. The melting point of the first insulating member 24 is higher than that of the separator 26. In the event of thermal runaway of the battery cell 20, even if the separator 26 melts, the first insulating member 24 can still separate the electrode assembly 23 from the first wall 211.

[0174] Please refer to Figures 6 and 7, and further to Figures 8 and 9. Figure 8 is a structural schematic diagram of the second insulating member and the first insulating member of a battery cell provided in some embodiments of this application, and Figure 9 is a partial enlarged view of point A in Figure 7. According to some embodiments of this application, the battery cell 20 further includes a second insulating member 27 and a third insulating member 28. The second insulating member 27 encloses at least a portion of the electrode assembly 23; the third insulating member 28 connects the separator 26 and the second insulating member 27, and at least a portion of the third insulating member 28 is located between the electrode assembly 23 and the first wall 211. The melting point of the third insulating member 28 is higher than the melting point of the separator 26.

[0175] The second insulating member 27 can be used to wrap the components of the electrode assembly 23 to facilitate separation of the electrode assembly 23 from the housing 21. In some embodiments, the second insulating member 27 can be a Mylar film.

[0176] In some embodiments, the electrode assembly 23 has a first end face facing the first wall 211, a second end face facing away from the first wall 211, and an outer peripheral surface connecting the first end face and the second end face. The second insulating member 27 can wrap around the first end face and the outer peripheral surface of the electrode assembly 23. The outer peripheral surface of the electrode assembly 23 is disposed around the first end face.

[0177] In some embodiments, the material of the third insulating member 28 may be the same as the material of the first insulating member 24.

[0178] In some embodiments, the melting point of the third insulating member 28 may be greater than 250°C. When the battery cell 20 experiences thermal runaway, the third insulating member 28 is not easily melted. Even if the separator 26 melts, the third insulating member 28 can still separate the electrode assembly 23 from the first wall 211.

[0179] In some embodiments, a portion of the third insulating member 28 may be located between the electrode assembly 23 and the isolator 26, and the third insulating member 28 connects the isolator 26 and the portion of the second insulating member 27 facing the isolator 26; or, a portion of the third insulating member 28 may be located between the isolator 26 and the first wall 211, and another portion of the third insulating member 28 may be located between the outer peripheral surface of the electrode assembly 23 and the housing 212, and the other portion of the third insulating member 28 may be connected to the portion of the second insulating member 27 that encloses the outer peripheral surface of the electrode assembly 23.

[0180] In the above scheme, the second insulating member 27 encloses at least a portion of the electrode assembly 23 to reduce the risk of short circuit between the electrode assembly 23 and the housing 21. Compared to the separator 26, the third insulating member 28 has a higher melting point. Even if the separator 26 melts, the third insulating member 28 can still separate the electrode assembly 23 from the first wall 211, thereby improving the reliability of the battery cell 20.

[0181] According to some embodiments of this application, the third insulating member 28 includes a first portion 281 and a second portion 282 that are interconnected. The first portion 281 is located between the insulating member 26 and the first wall 211 and is connected to the insulating member 26. The second portion 282 is stacked with the second insulating member 27 and is connected to the second insulating member 27.

[0182] In some embodiments, the first part 281 and the second part 282 may be integrally formed.

[0183] The first part 281 is located between the isolator 26 and the first wall 211 and is connected to the isolator 26. The second part 282 passes over the isolator 26 and is connected to the second insulating member 27 that covers the outer peripheral surface of the electrode assembly 23, so that the third insulating member 28 connects the isolator 26 and the electrode assembly 23 into one unit.

[0184] In the above scheme, the first part 281 is connected to the isolator 26, the second part 282 passes over the isolator 26 and is connected to the second insulating member 27, and the third insulating member 28 can provide a constraint force for the isolator 26, which facilitates the assembly of the isolator 26 and the electrode assembly 23.

[0185] Please refer to Figures 7 to 9. According to some embodiments of this application, on the same projection plane perpendicular to the thickness direction Z of the first wall, the orthographic projection of the first portion 281 does not overlap with the orthographic projection of the first insulating member 24.

[0186] When viewed along the thickness direction Z of the first wall, the first part 281 does not overlap with the first insulating element 24.

[0187] In the above scheme, the orthographic projection of the first part 281 does not overlap with the orthographic projection of the first insulating member 24, which facilitates the improvement of the space utilization rate inside the outer casing 21 in the thickness direction Z of the first wall, so that the battery cell 20 can have a higher energy density.

[0188] Please refer to Figure 9. According to some embodiments of this application, the first part 281 is spaced apart from the first insulating member 24.

[0189] In some embodiments, the number of third insulating members 28 may be two, with the two third insulating members 28 spaced apart in the first direction X, and the first insulating member 24 located between the two third insulating members 28. For example, the second portions 282 of the two third insulating members 28 are located at both ends of the electrode assembly 23 in the first direction X, and the first insulating member 24 is located between the first portions 281 of the two third insulating members 28.

[0190] In some embodiments, the first portion 281 is spaced apart from the first insulating member 24 along the first direction X.

[0191] In the above scheme, the first part 281 and the first insulating member 24 are spaced apart, which facilitates assembly and reduces the risk of interference between the first part 281 and the first insulating member 24.

[0192] According to some embodiments of this application, the distance between the first portion 281 and the first insulating member 24 is greater than or equal to 0.1 mm and less than or equal to 5 mm.

[0193] The distance between the first part 281 and the first insulating element 24 can be, but is not limited to, any one value or a range between any two values ​​of 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.

[0194] In the above scheme, the distance between the first part 281 and the first insulating member 24 satisfies the above relationship. Under the condition of low assembly difficulty, the first part 281 and the first insulating member 24 can have a large overlap area with the electrode assembly 23 in the thickness direction Z of the first wall. This facilitates the separation of the electrode assembly 23 and the first wall 211 by the first part 281 and the first insulating member 24 in the event of thermal runaway of the battery cell 20, thereby reducing the risk of short circuit between the electrode assembly 23 and the first wall 211.

[0195] Referring to Figure 9, according to some embodiments of this application, the battery cell 20 further includes a second adhesive layer 29. The first portion 281 is bonded to the separator 26 through the second adhesive layer 29, and the second portion 282 is bonded to the second insulating member 27 through the second adhesive layer 29.

[0196] The material of the second adhesive layer 29 can be the same as that of the first adhesive layer 25.

[0197] The second adhesive layer 29 is used to bond the first part 281 to the spacer 26 and the second part 282 to the second insulating member 27.

[0198] In the above scheme, the first part 281 is bonded to the separator 26 through the second adhesive layer 29, which is convenient to operate and facilitates the assembly of the first part 281 and the separator 26; the second part 282 is bonded to the second insulating part 27 through the second adhesive layer 29, and the second part 282 and the second insulating part 27 are firmly connected, which facilitates the assembly of the second part 282 and the second insulating part 27.

[0199] According to some embodiments of this application, the thickness of the third insulating element 28 is greater than or equal to 7 μm and less than or equal to 150 μm.

[0200] The thickness of the third insulating element 28 can be any single value or a range between any two values ​​from 7μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, to 150μm.

[0201] In the above scheme, the thickness of the third insulating member 28 satisfies the above relationship. While satisfying the requirement that the third insulating member 28 separates the electrode assembly 23 from the housing 21, the third insulating member 28 occupies a small assembly space and can reduce material waste.

[0202] According to some embodiments of this application, the thickness of the second adhesive layer 29 is greater than or equal to 3 μm and less than or equal to 50 μm.

[0203] The thickness of the second adhesive layer 29 can be any one value or a range between any two values ​​from 3μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, and 50μm.

[0204] In the above scheme, the thickness of the second adhesive layer 29 satisfies the above relationship, which can meet the connection requirements of the third insulating member 28, the isolating member 26, and the second insulating member 27. Furthermore, the structure after the third insulating member 28 is connected to the isolating member 26 and the second insulating member 27 occupies a small assembly space.

[0205] Please refer to Figures 4 and 8. According to some embodiments of this application, in the width direction Y of the first wall, the dimension of the first wall 211 is W1, and the dimension of the third insulating member 28 is W3, satisfying that 0.5≤W3 / W1≤0.9.

[0206] W3 / W1 can be expressed as the ratio between the dimension of the third insulating member 28 in the width direction Y of the first wall and the width of the first wall 211.

[0207] In some embodiments, W3 / W1 can be, but is not limited to, any one value or a range between any two point values ​​among 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, and 0.9.

[0208] In the above scheme, the width of the first wall 211 and the dimension of the third insulating member 28 in the width direction Y of the first wall satisfy the above relationship. Under the condition that the third insulating member 28 and the first wall 211 do not interfere, the dimension of the third insulating member 28 in the width direction Y of the first wall can be designed to be larger, so that the third insulating member 28 and the electrode assembly 23 have a larger overlap area in the width direction Y of the first wall, which is beneficial to reduce the risk of short circuit between the electrode assembly 23 and the first wall 211 when the battery cell 20 is thermally runaway.

[0209] Referring to Figures 3, 4, and 6, according to some embodiments of this application, the battery cell 20 further includes electrode terminals 30, the housing 21 includes a housing 212 and an end cap 213, the housing 212 has an opening, the end cap 213 covers the opening, and the electrode terminals 30 are disposed on the end cap 213; the housing 212 includes a bottom wall 212a and a side wall 212b, the side wall 212b surrounds the bottom wall 212a, one end of the side wall 212b is connected to the bottom wall 212a, and the other end of the side wall 212b is connected to the end cap 213, and the bottom wall 212a is a first wall 211.

[0210] The electrode terminal 30 is used for internal electrical connection with the electrode assembly 23 and external electrical connection with the external conductive parts of the battery cell 20. The electrode terminal 30 is used for outputting or inputting electrical energy into the battery cell 20.

[0211] The bottom wall 212a is the first wall 211. The bottom wall 212a and the end cap 213 are arranged opposite each other in the thickness direction Z of the first wall, so that the pressure relief mechanism 22 and the electrode terminal 30 are arranged opposite each other in the thickness direction Z of the first wall.

[0212] In the above scheme, the pressure relief mechanism 22 and the electrode terminal 30 are arranged opposite to each other in the thickness direction Z of the first wall. In the battery device 100 composed of the battery cell 20, when the battery cell 20 thermally runs away, the discharge of the battery cell 20 released by the pressure relief mechanism 22 is less likely to act on the components connected to the electrode terminal 30, thereby improving the reliability of the battery device 100.

[0213] According to some embodiments of this application, this application also provides a battery device 100, which includes a battery cell 20 provided according to any of the above embodiments.

[0214] According to some embodiments of this application, this application also provides an electrical device, which includes a battery device 100 provided according to any of the above embodiments, the battery device 100 being used to provide electrical energy.

[0215] The power supply device can be any of the above-mentioned systems or devices using battery device 100.

[0216] According to some embodiments of this application, please refer to Figures 3 to 9. This application provides a battery cell 20, which includes a housing 21, a pressure relief mechanism 22, an electrode assembly 23, a first insulating member 24, an electrode terminal 30, an insulating member 26, a second insulating member 27, and a third insulating member 28.

[0217] The outer casing 21 includes a housing 212 and an end cap 213. The housing 212 has an opening, and the end cap 213 covers the opening. The housing 212 includes a bottom wall 212a and a side wall 212b. The side wall 212b surrounds the bottom wall 212a. One end of the side wall 212b is connected to the bottom wall 212a, and the other end of the side wall 212b is connected to the end cap 213. The bottom wall 212a is a first wall 211.

[0218] Electrode terminals 30 are disposed on end caps 213, and pressure relief mechanisms 22 are disposed on first walls 211.

[0219] The electrode assembly 23 is disposed inside the housing 21, and the tabs of the electrode assembly 23 are electrically connected to the electrode terminals 30.

[0220] The second insulating member 27 encloses at least a portion of the electrode assembly 23. The second insulating member 27 includes a portion of the electrode assembly 23 facing the sidewall 212b and a portion of the electrode assembly 23 facing the first wall 211. The provision of the second insulating member 27 can improve the insulation effect between the electrode assembly 23 and the housing 21.

[0221] The isolator 26 is disposed between the electrode assembly 23 and the first wall 211, and a portion of the second insulating member 27 is located between the electrode assembly 23 and the isolator 26. The isolator 26 separates the electrode assembly 23 from the first wall 211.

[0222] The third insulating member 28 includes a first portion 281 and a second portion 282 that are interconnected. The first portion 281 is located between the separator 26 and the first wall 211 and is connected to the separator 26 through a second adhesive layer 29. The second portion 282 extends beyond the separator 26 and is connected to the second insulating member 27 through the second adhesive layer 29. The second portion 282 is located between the side wall 212b and the second insulating member 27. The melting point of the third insulating member 28 is higher than that of the separator 26, and the melting point of the third insulating member 28 is greater than 250°C. The third insulating member 28 can provide a restraining force for the separator 26, facilitating the assembly of the separator 26 and the electrode assembly 23. At the same time, the third insulating member 28 has a high melting point, which can separate the electrode assembly 23 from the first wall 211 in the event of thermal runaway of the battery cell 20.

[0223] The first insulating member 24 is disposed between the first walls 211 of the separator 26. On the same projection plane perpendicular to the thickness direction Z of the first wall, the orthographic projection of the first portion 281 does not overlap with the orthographic projection of the first insulating member 24. The melting point of the first insulating member 24 is higher than that of the separator 26, and the melting point of the first insulating member 24 is greater than 250°C. On the same projection plane perpendicular to the first thickness direction, the orthographic projection of the first insulating member 24 at least partially overlaps with the orthographic projection of the pressure relief mechanism 22. A gap exists between the first insulating member 24 and the pressure relief mechanism 22 along the thickness direction Z of the first wall.

[0224] When the battery cell 20 constitutes the battery device 100, since the melting point of the first insulating member 24 is greater than 250°C, the first insulating member 24 is not easily melted when the battery cell 20 experiences thermal runaway. The first insulating member 24 can separate the electrode assembly 23 and the first wall 211 where the pressure relief mechanism 22 is located. At the same time, the first insulating member 24 and the pressure relief mechanism 22 have an overlapping area. The first insulating member 24 can block at least part of the pressure relief port of the pressure relief mechanism 22 to block the particles inside the battery cell 20, reduce the risk that the particles inside the battery cell 20 will be directly ejected from the pressure relief port and damage other components inside the battery device 100, thereby improving the reliability of the battery device 100 constituted by the battery cell 20. Along the thickness direction Z of the first wall, the first insulating member 24 and the pressure relief mechanism 22 are spaced apart to facilitate pressure relief by the pressure relief mechanism 22 and reduce the influence of the first insulating member 24 on the pressure relief mechanism 22. For example, when the battery cell 20 thermally runs away, the pressure relief mechanism 22 forms a pressure relief port, and the airflow inside the casing 21 can flow to the pressure relief port through the gap between the first insulating member 24 and the pressure relief mechanism 22, thereby improving the reliability of the battery device 100.

[0225] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A single battery cell, comprising: The outer shell, including the first wall; A pressure relief mechanism is installed on the first wall; Electrode assembly, disposed within the housing; A first insulating element is disposed between the electrode assembly and the first wall; The first insulating component has a melting point greater than 250°C, and on the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first insulating component and the orthographic projection of the pressure relief mechanism at least partially overlap.

2. The battery cell of claim 1, wherein, Along the thickness direction of the first wall, there is a gap between the first insulating element and the pressure relief mechanism.

3. The battery cell of claim 2, wherein, The battery cell further includes a first adhesive layer, and the first insulating member is bonded to the first wall through the first adhesive layer. The first insulating member includes an adhesive area with the first adhesive layer and a non-adhesive area without the first adhesive layer. On the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the non-adhesive area at least partially overlaps with the orthographic projection of the pressure relief mechanism, and there is a gap between the non-adhesive area and the pressure relief mechanism.

4. The battery cell of claim 3, wherein, The thickness of the first adhesive layer is greater than or equal to 3 μm and less than or equal to 100 μm.

5. The battery cell of claim 3, wherein, The first adhesive layer includes a first sub-adhesive layer and a second sub-adhesive layer. The viscous region includes a first viscous region provided with the first sub-adhesive layer and a second viscous region provided with the second sub-adhesive layer. The first viscous region and the second viscous region are spaced apart along a first direction. The non-viscous region is located between the first viscous region and the second viscous region. The first direction is perpendicular to the thickness direction of the first wall.

6. The battery cell of claim 5, wherein, The first direction is parallel to the length direction of the first wall.

7. The battery cell of claim 5, wherein, Along the first direction, the minimum distance between the first sub-adhesive layer and the pressure relief mechanism is greater than or equal to 2 mm, and the minimum distance between the second sub-adhesive layer and the pressure relief mechanism is greater than or equal to 2 mm.

8. The battery cell of claim 1, wherein, The first insulating element is a sheet structure, and the thickness of the first insulating element is greater than or equal to 7 μm and less than or equal to 400 μm.

9. The battery cell of claim 1, wherein, In the width direction of the first wall, the dimension of the first wall is W1, and the dimension of the first insulating element is W2, satisfying that 0.5≤W2 / W1≤1.

10. The battery cell of claim 1, wherein, The material of the first insulating component is polyimide, soluble polytetrafluoroethylene, polyarylether ketone, polyphenylene sulfide, tetrafluoroethylene-ethylene copolymer, perfluoroethylene propylene, or high-temperature resistant nylon.

11. The battery cell of claim 1, wherein, The battery cell also includes: An isolator is disposed between the electrode assembly and the first wall; The first insulating element is disposed between the insulating element and the first wall, and the melting point of the first insulating element is higher than the melting point of the insulating element.

12. The battery cell of claim 11, wherein, The battery cell also includes: A second insulating element encloses at least a portion of the electrode assembly; A third insulating element connects the isolator and the second insulating element, at least a portion of the third insulating element is located between the electrode assembly and the first wall, and the melting point of the third insulating element is higher than that of the isolator.

13. The battery cell of claim 12, wherein, The third insulating member includes a first part and a second part that are interconnected. The first part is located between the insulating member and the first wall and is connected to the insulating member. The second part is stacked on top of the second insulating member and is connected to the second insulating member.

14. The battery cell of claim 13, wherein, On the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first portion does not overlap with the orthographic projection of the first insulating element.

15. The battery cell of claim 14, wherein, The first part is spaced apart from the first insulating element.

16. The battery cell of claim 15, wherein, The distance between the first part and the first insulating element is greater than or equal to 0.1 mm and less than or equal to 5 mm.

17. The battery cell of claim 13, wherein, The battery cell further includes a second adhesive layer, wherein the first portion is bonded to the separator through the second adhesive layer, and the second portion is bonded to the second insulating component through the second adhesive layer.

18. The battery cell of claim 17, wherein, The thickness of the third insulating element is greater than or equal to 7 μm and less than or equal to 150 μm.

19. The battery cell of claim 17, wherein, The thickness of the second adhesive layer is greater than or equal to 3 μm and less than or equal to 50 μm.

20. The battery cell of claim 12, wherein, In the width direction of the first wall, the dimension of the first wall is W1, and the dimension of the third insulating member is W3, satisfying 0.5≤W3 / W1≤0.

9.

21. The battery cell of claim 1, wherein, The battery cell further includes electrode terminals, the housing includes a shell and an end cap, the shell has an opening, the end cap covers the opening, and the electrode terminals are disposed on the end cap; The housing includes a bottom wall and a side wall. The side wall surrounds the bottom wall. One end of the side wall is connected to the bottom wall, and the other end of the side wall is connected to the end cap. The bottom wall is the first wall.

22. A battery device comprising a battery cell as claimed in any one of claims 1-21.

23. An electrical device comprising the battery device as claimed in claim 22, the battery device being used to provide electrical energy.

Images