Battery cells, battery packs, and electrical devices

Abstract

This application provides a battery cell, a battery device, and an electrical device. The battery cell includes a casing, an electrode assembly, a first insulating member, and a phase change element. The casing has a receiving cavity, the electrode assembly is housed within the receiving cavity, the first insulating member covers the outer surface of the electrode assembly, and the first insulating member has a hollow cavity. The phase change element is disposed within the hollow cavity and configured to generate a phase change. The battery cell provided in this application improves the thermal insulation effect between battery cells, reduces the risk of thermal runaway propagation from battery cells leading to wider thermal runaway, and helps reduce the assembly difficulty of the battery device and increase the energy density of the battery device.

Description

Technical Field

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

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] In the development of battery cell technology, in addition to improving the performance of battery cells, their reliability is also a crucial consideration. Therefore, improving the reliability of battery cells is a continuous challenge in battery cell technology. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical device, which helps to improve the reliability of the battery cell.

[0005] This application is achieved through the following technical solution:

[0006] In a first aspect, the battery cell provided in the embodiments of this application includes a casing, an electrode assembly, a first insulating member, and a phase change member. The casing has a receiving cavity, the electrode assembly is received in the receiving cavity, the first insulating member covers the outer surface of the electrode assembly, the first insulating member has a hollow cavity, the phase change member is disposed in the hollow cavity, and the phase change member is configured to generate a phase change.

[0007] The battery cell provided in this application embodiment incorporates a phase change element within the hollow cavity of the first insulating member. This allows the phase change process of the phase change element to absorb heat when the battery cell temperature rises, reducing the risk of heat transfer from the battery cell to adjacent battery cells and thus preventing thermal runaway. This improves the thermal insulation between battery cells, reduces the risk of thermal runaway propagating from individual cells and causing wider thermal runaway, thereby enhancing the reliability of the battery cell. When the battery cell is used in a battery device, the thermal insulation components between battery cells can be omitted or simplified, reducing the assembly difficulty of the battery device and improving its energy density.

[0008] According to some embodiments of this application, the phase transition temperature T of the phase change element satisfies: 80℃≤T≤120℃.

[0009] In the above scheme, setting 80℃≤T≤120℃ helps to reduce the risk that the phase change component will undergo phase change before the thermal runaway of the battery cell and will not be able to undergo phase change and absorb heat when the battery cell is in thermal runaway. It also facilitates the phase change component to generate phase change and absorb heat in a timely manner during the thermal runaway of the battery cell, so as to reduce the risk of further spread of the thermal runaway of the battery cell.

[0010] According to some embodiments of this application, the first insulating member includes a first clamping layer and a second clamping layer, the peripheries of the first clamping layer and the second clamping layer are attached to each other and surround to form a hollow cavity, and the phase change member is clamped between the first clamping layer and the second clamping layer.

[0011] The above scheme simplifies the manufacturing process of battery cells, reduces the loss of phase change components in the hollow cavity, and further improves the reliability of battery cells.

[0012] According to some embodiments of this application, the electrode assembly includes an electrode body and a tab. The tab extends from a first end of the electrode body along a first direction. A phase change element is disposed on a side of the electrode body along a second direction, which intersects the first direction. The battery cell also includes a second insulating element disposed on the side of the casing facing the tab. The first insulating element and the second insulating element are thermally fused together. Along the first direction, the end of the phase change element near the first end and the end of the first insulating element near the first end have a first distance d, where d ≥ 5 mm.

[0013] In the above scheme, by setting d≥5mm, it is easier to carry out the heat fusion connection between the first insulating component and the second insulating component, which helps to reduce the process difficulty of the battery cell.

[0014] According to some embodiments of this application, the dimension of the first insulating member along the first direction is h, and 10% ≤ d / h ≤ 20%.

[0015] In the above scheme, by setting 10%≤d / h≤20%, the connection convenience of the first insulating component and the second insulating component is improved, and the space occupied by the phase change component along the first direction is also improved, so as to increase the heat absorption of the phase change component during the phase change process under the condition of thermal runaway of the battery cell.

[0016] According to some embodiments of this application, the material of the phase change element includes paraffin wax or polyethylene wax.

[0017] In the above scheme, the phase transition points of paraffin wax and polyethylene wax can be artificially adjusted, and both have high enthalpy values, which can absorb more heat during the phase transition process. In addition, paraffin wax and polyethylene are inexpensive and have relatively stable performance during operation.

[0018] According to some embodiments of this application, the electrode assembly includes an electrode body and a tab, with the tab extending from an end of the electrode body along a first direction. The electrode body includes two first surfaces opposite each other along a second direction and two second surfaces opposite each other along a third direction. The first direction, the second direction, and the third direction are perpendicular to each other. The two first surfaces connect to the two second surfaces. The area of ​​the first surface is larger than the area of ​​the second surface. At least one side of the first surface is provided with a phase change element.

[0019] In the above scheme, during the thermal runaway of the battery cell, the heat of the electrode body is transferred away more through the first surface. By setting a phase change element on the side of at least one of the first surfaces, the heat of the electrode assembly can be absorbed by the phase change element in time in the event of thermal runaway of the battery cell.

[0020] According to some embodiments of this application, the dimensions of all electrode bodies of a battery cell along the second direction are t1, the dimensions of the receiving cavity along the second direction are t2, and the sum of the maximum dimensions of the first insulating member and the phase change member on the two first surface sides along the second direction is e1, where e1≤0.93t2-t1.

[0021] In the above scheme, by setting e1≤0.93t2-t1, it is beneficial to control the group margin of the battery cell to be less than or equal to 93%. This helps to reduce the risk of battery cells being difficult to assemble due to excessive group margin or poor wettability of electrolyte to electrode components.

[0022] According to some embodiments of this application, at least one side of the second surface is provided with a phase change element.

[0023] In the above scheme, in the event of thermal runaway of a battery cell, the phase change component on the second surface side can also absorb part of the heat of the battery assembly, which is beneficial to further improve the heat insulation effect between battery cells and reduce the risk of thermal runaway of a battery cell spreading to adjacent battery cells.

[0024] According to some embodiments of this application, the sum of the dimensions of the electrode body along the third direction is t3, the dimension of the receiving cavity along the third direction is t4, and the sum of the maximum dimensions of the first insulating member and the phase change member on the two second surface sides along the third direction is e2, where e2≤t4-t3-1mm.

[0025] In the above scheme, by setting e2≤t4-t3-1mm, it is easy to ensure that the sum of the gaps between the first insulating parts on both sides of the third direction and the shell is at least 1mm during the process of inserting the electrode assembly into the shell. This facilitates the assembly of the electrode assembly into the shell and reduces the risk of the electrode assembly being scratched by the shell during the process of inserting it into the shell.

[0026] According to some embodiments of this application, the electrode body further includes a third surface, the tab is led out from the first end of the electrode body, and the third surface is located on the side of the electrode body opposite to the first end; a phase change element is disposed on the side of the third surface.

[0027] In the above scheme, the heat of the battery cell can also be absorbed by the phase change element on the third surface side, so as to absorb the heat of the electrode assembly through the phase change element on the third surface side, further reducing the heat transferred from the battery cell to other battery cells, and further reducing the risk of thermal runaway propagation of the battery cell.

[0028] According to some embodiments of this application, the first insulating member on the third surface side has a through hole, which is disposed through the first insulating member along a first direction.

[0029] In the above scheme, the electrolyte can be immersed into the electrode assembly through the through hole, which is beneficial to improving the wetting efficiency and wettability of the electrolyte to the electrode assembly, and thus improving the cycle performance of the battery cell.

[0030] Secondly, the battery device provided in the embodiments of this application includes the battery cell provided in any of the above embodiments.

[0031] The battery device provided in this application has the same technical effect as the battery cell provided in any of the above embodiments, and will not be described again here.

[0032] According to some embodiments of this application, the electrode assembly includes an electrode body and tabs, the tabs extending from an end of the electrode body along a first direction, and phase change elements disposed on both sides of the electrode body along a second direction, the first direction intersecting the second direction. The battery device includes a plurality of battery cells, at least a portion of which are arranged along the second direction.

[0033] In the above scheme, two layers of phase change elements isolate the electrode assemblies of any two adjacent battery cells. This helps to further improve the heat insulation effect between battery cells, reduce the risk of thermal runaway spreading between battery cells, and further improve the reliability of the battery device. Furthermore, by thinning or omitting the heat insulation between two adjacent battery cells along the second direction, the overall structure of the battery device is simplified, the space occupied by the heat insulation along the second direction is reduced, and thus the energy density of the battery device is improved.

[0034] According to some embodiments of this application, two adjacent battery cells along the second direction are bonded together.

[0035] In the above scheme, the two adjacent battery cells along the second direction are insulated only by a phase change element, without the need to set up insulation components or other structures between the battery cells. This is beneficial to simplify the structure of the battery device, simplify the assembly process of the battery device, and improve the energy density of the battery device.

[0036] Thirdly, the electrical device provided in the embodiments of this application includes the battery device provided in any of the above embodiments, and the battery device is used to provide electrical energy.

[0037] The electrical device provided in this application embodiment has the same technical effect as the battery device provided in this application embodiment, and will not be described again here.

[0038] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0039] 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.

[0040] Figure 1 This is a schematic diagram of the vehicle structure provided in an embodiment of this application;

[0041] Figure 2 This is a schematic diagram of the structure of the battery device provided in the embodiments of this application;

[0042] Figure 3 This is a schematic diagram of the structure of a battery cell assembly in a battery device provided in an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of the exploded structure of a single battery cell provided in an embodiment of this application;

[0044] Figure 5 This is a schematic diagram of the structure of the first insulating component and the phase change component in a battery cell provided in an embodiment of this application;

[0045] Figure 6 This is a schematic diagram of the structure of the first insulating element in a battery cell provided in an embodiment of this application;

[0046] Figure 7 This is a front view of a portion of the structure of a battery cell provided in an embodiment of this application;

[0047] Figure 8This is a bottom view of the first insulating element in a battery cell provided in an embodiment of this application.

[0048] The accompanying drawings are not necessarily drawn to scale.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-Vehicle; 1a-Motor; 1b-Controller;

[0051] 10 - Battery assembly; 11 - Housing; 111 - First sub-housing; 112 - Second sub-housing;

[0052] 20-Battery cell module;

[0053] 30 - Battery cell; 31 - Housing; 31a - Receiving cavity; 311 - Housing; 312 - End cap; 32 - Electrode assembly; 321 - Electrode body; 321a - First surface; 321b - Second surface; 321c - Third surface; 321d - First end; 322 - Tab; 33 - Electrode terminal;

[0054] 40 - First insulating element; 41 - First clamping layer; 42 - Second clamping layer; 40a - Hollow cavity; 40b - Through hole;

[0055] 50 - Phase change component;

[0056] 60 - Second insulating element;

[0057] X - First direction; Y - Second direction; Z - Third direction. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0060] 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.

[0061] 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.

[0062] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0063] 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).

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0069] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0070] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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, carbon electrodes, 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.).

[0077] 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 battery cells may also be used.

[0078] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0079] 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, copper, aluminum, carbon electrode, carbon, nickel, or titanium, etc.

[0080] 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.

[0081] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. 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 in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0082] In some embodiments, the diaphragm is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0083] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0084] In some embodiments, the membrane 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.

[0085] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0086] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0087] In some embodiments, the housing includes an end cap and a shell, the shell 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 shell may have one or more openings. The end cap may also be provided one or more times.

[0088] 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 through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0089] In some implementations, an explosion-proof valve is provided on the housing. The explosion-proof valve is used to release the internal pressure of the battery cells.

[0090] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. There are no particular limitations in the embodiments of this application.

[0091] During operation, battery cells inevitably generate heat. As this heat accumulates, the temperature of the battery cell rises, potentially leading to thermal runaway. In some technologies, when a battery cell experiences thermal runaway, the heat can be transferred to adjacent cells, causing them to also experience thermal runaway, thus triggering a wider-ranging thermal runaway. This severely impacts the reliability of the battery cells.

[0092] In view of this, the present application provides a battery cell including a casing, an electrode assembly, a first insulating member and a phase change member. The casing has a receiving cavity, the electrode assembly is received in the receiving cavity, the first insulating member covers the outer surface of the electrode assembly, the first insulating member has a hollow cavity, the phase change member is disposed in the hollow cavity, and the phase change member is configured to generate a phase change.

[0093] The battery cell provided in this application embodiment incorporates a phase change element within the hollow cavity of the first insulating member. This allows the phase change process of the phase change element to absorb heat when the battery cell temperature rises, reducing the risk of heat transfer from the battery cell to adjacent battery cells and thus preventing thermal runaway. This improves the thermal insulation between battery cells, reduces the risk of thermal runaway propagating from individual cells and causing wider thermal runaway, thereby enhancing the reliability of the battery cell. When the battery cell is used in a battery device, the thermal insulation components between battery cells can be omitted or simplified, reducing the assembly difficulty of the battery device and improving its energy density.

[0094] The technical solutions described in the embodiments of this application are applicable to battery cells, battery devices including battery cells, and electrical devices using battery devices.

[0095] 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.

[0096] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric bicycles, electric motorcycles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0097] For ease of explanation, the following embodiments will be described using a vehicle 1 as an example of an electrical device according to an embodiment of this application.

[0098] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1 provided in an embodiment of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 10 is installed inside vehicle 1, and the battery device 10 can be located at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1; for example, the battery device 10 can serve as the operating power source for vehicle 1's electrical system, such as meeting the power requirements for starting, navigation, and operation of vehicle 1.

[0099] The vehicle 1 may also include a controller 1b and a motor 1a. The controller 1b is used to control the battery device 10 to supply power to the motor 1a, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0100] In some embodiments of this application, the battery device 10 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0101] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of the battery device 10 provided in the embodiments of this application. Figure 3 This is a schematic diagram of the structure of the battery cell assembly 20 in the battery device 10 provided in this application embodiment. The battery device 10 includes a housing 11 and battery cells 30, with the battery cells 30 housed within the housing 11. The housing 11 provides a space for accommodating the battery cells 30, and the housing 11 can adopt various structures. In some embodiments, the housing 11 may include a first sub-housing 111 and a second sub-housing 112, which overlap each other, and together define a space for accommodating the battery cells 30. The second sub-box 112 can be a hollow structure with one end open, and the first sub-box 111 can be a plate-like structure. The first sub-box 111 covers the opening side of the second sub-box 112 so that the first sub-box 111 and the second sub-box 112 together define the accommodating space. Alternatively, the first sub-box 111 and the second sub-box 112 can both be hollow structures with one side open, and the opening side of the first sub-box 111 covers the opening side of the second sub-box 112.

[0102] In the battery device 10, there can be multiple battery cells 30, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 30 are connected in both series and parallel configurations. Multiple battery cells 30 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 30 is housed within the housing 11. Alternatively, the battery device 10 can also consist of multiple battery cells 30 first connected in series, parallel, or in a mixed manner to form a battery cell assembly 20, and then the multiple battery cell assemblies 20 are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 11. The battery device 10 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 30.

[0103] Among them, the battery cell 30 can be a secondary battery or a primary battery; the battery cell 30 can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited to these.

[0104] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the exploded structure of a battery cell 30 provided in an embodiment of this application. Figure 4As shown, the battery cell 30 includes a housing 31, an electrode assembly 32, and electrode terminals 33. The housing 31 includes a casing 311 and an end cap 312. The casing 311 has an opening, and the end cap 312 closes the opening to isolate the internal environment of the battery cell 30 from the external environment.

[0105] The housing 311 is a component used to cooperate with the end cap 312 to form the internal environment of the battery cell 30, wherein the formed internal environment can accommodate the electrode assembly 32, electrolyte, and other components. The housing 311 and the end cap 312 can be independent components. The housing 311 can have various shapes and sizes. Specifically, the shape of the housing 311 can be determined according to the specific shape and size of the electrode assembly 32. The housing 311 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0106] End cap 312 refers to a component that covers the opening of housing 311 to isolate the internal environment of battery cell 30 from the external environment. The shape of end cap 312 can be adapted to the shape of housing 311 to fit it. Optionally, end cap 312 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 312 is not easily deformed under pressure and impact, giving battery cell 30 higher structural strength and improved reliability. Functional components such as electrode terminals 33 can be provided on end cap 312. Electrode terminals 33 can be used for electrical connection with electrode assembly 32 to output or input electrical energy to battery cell 30. The material of end cap 312 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose special limitations on this. In some embodiments, an insulating structure may be provided on the inner side of the end cap 312. The insulating structure can be used to isolate the electrical connection components within the housing 311 from the end cap 312 to reduce the risk of short circuits. For example, the insulating structure may be made of plastic, rubber, etc.

[0107] Electrode assembly 32 is the component in the battery cell 30 where electrochemical reactions occur. The housing 311 may contain one or more electrode assemblies 32. The electrode assembly 32 is mainly formed by winding or stacking positive and negative electrode plates, and typically a separator is provided between the positive and negative electrode plates to separate them and prevent internal short circuits. The portions of the positive and negative electrode plates containing active material constitute the electrode body 321 of the electrode assembly 32, while the portions of the positive and negative electrode plates without active material each constitute a tab 322. The positive and negative tabs may be located together at one end of the electrode body 321 or separately at both ends of the electrode body 321. During the charging and discharging process of the battery cell 30, the positive and negative active materials react with the electrolyte, and the tabs 322 connect to the electrode terminals 33 to form a current loop.

[0108] Firstly, such as Figure 4 and Figure 5 As shown, this application embodiment provides a battery cell 30 including a housing 31, an electrode assembly 32, a first insulating member 40, and a phase change member 50. The housing 31 has a receiving cavity 31a, the electrode assembly 32 is received in the receiving cavity 31a, the first insulating member 40 covers the outer surface of the electrode assembly 32, the first insulating member 40 has a hollow cavity 40a, the phase change member 50 is disposed in the hollow cavity 40a, and the phase change member 50 is configured to generate a phase change.

[0109] The battery cell 30 includes an electrode assembly 32. Optionally, the battery cell 30 may include one or more electrode assemblies 32. A first insulating member 40 covers the outer surface of the electrode assembly 32. Optionally, the first insulating member 40 may cover the outer surface of one or more electrode assemblies 32. For example, the first insulating member 40 covers the outer surface of all electrode assemblies 32 in the battery cell 30 to achieve insulation between the electrode assembly 32 and the outer casing 31. The first insulating member 40 may be a Mylar film, etc.

[0110] The first insulating member 40 covers the outer surface of the electrode assembly 32. Optionally, the first insulating member 40 may cover all or part of the outer surface of the electrode assembly 32 as needed. For example, the electrode assembly 32 may include an electrode body 321 and a tab 322. The tab 322 extends from the end of the electrode body 321, and the first insulating member 40 may cover the other surfaces of the electrode body 321 except for the end where the tab 322 extends.

[0111] The phase change element 50 is disposed in the hollow cavity 40a. During the process of the temperature rise of the battery cell 30, the phase change element 50 absorbs heat and generates a phase change. Optionally, the phase change process of the phase change element 50 can be from solid to liquid, or the phase change process of the phase change element 50 can be from liquid to gas.

[0112] Optionally, the material of the phase change element 50 can be, but is not limited to, inorganic crystalline hydrated salts, paraffin waxes, polyethylene waxes, formic acid, butyl stearate, polyethylene glycol, or hexadecanoic acid. The phase change temperature of the phase change element 50 can be reasonably set according to the operating temperature and thermal runaway temperature of the battery cell 30. In the event of thermal runaway of the battery cell 30, when the electrode assembly 32 generates a large amount of heat, the phase change element 50 can promptly generate a phase change and absorb the heat of the electrode assembly 32 or adjacent battery cells 30, thereby reducing the risk of further spread of thermal runaway of the battery cell 30.

[0113] Optionally, the phase change element 50 can be disposed on any one or more sides of the electrode assembly 32. For example, a phase change element 50 is disposed on any side of the electrode assembly 32 covered by the first insulating member 40, so as to absorb more heat from the battery cell 30 from more directions through the phase change element 50.

[0114] The structural form of the hollow cavity 40a can be selected according to actual needs. For example, the hollow cavity 40a can be a cavity reserved during the production process of the first insulating component 40, or the hollow cavity 40a can be formed by the surrounding parts of the two sheet-like structures of the first insulating component 40 being attached to each other and the middle parts being separated from each other.

[0115] Optionally, the first insulating member 40 may have a hollow cavity 40a, which is located on multiple different sides of the electrode assembly 32. Alternatively, the first insulating member 40 may have multiple hollow cavities 40a, which are located on the same side of the electrode assembly 32.

[0116] Understandably, after the battery cells 30 are assembled into the battery device 10, multiple battery cells 30 are arranged in one direction. In the event of thermal runaway in any battery cell 30, the electrode assembly 32 of that battery cell 30 generates a large amount of heat. The phase change element 50 inside the electrode assembly 30 can absorb the heat of the electrode assembly 32 through a phase change, thereby reducing the heat transferred from the electrode assembly 32 to other adjacent battery cells 30. Conversely, in the event of thermal runaway in other adjacent battery cells 30, some of the heat transferred to that battery cell 30 can be absorbed through the phase change process within that battery cell 30, reducing the heat transferred to the electrode assembly 32 of that battery cell 30. This helps to reduce the risk of thermal runaway from adjacent battery cells 30 being transferred to the electrode assembly 32 of that battery cell 30.

[0117] In summary, by incorporating a phase change element 50 within the battery cell 30, the heat transferred from other battery cells 30 experiencing thermal runaway to the electrode assembly 32 of this battery cell 30 can be reduced, as can the heat transferred from this battery cell 30 to the electrode assembly 32 of adjacent battery cells 30 in the event of thermal runaway. This reduces the risk of thermal runaway from one battery cell 30 spreading to adjacent battery cells 30. Furthermore, under normal operating conditions, the phase change element 50 provides good thermal insulation between adjacent battery cells 30, thereby improving the stability of the cycle performance of the battery cell 30.

[0118] Furthermore, due to the use of the phase change element 50, during the assembly of the battery cells 30, it is not necessary to place heat insulation components between adjacent battery cells 30 to reduce the risk of thermal runaway propagation of the battery cells 30, or a thinner heat insulation component can be used to achieve the purpose of heat insulation. This simplifies the assembly process of the battery device 10, reduces the space occupied by the heat insulation component, and helps to improve the energy density of the battery device 10.

[0119] The battery cell 30 provided in this embodiment incorporates a phase change element 50 within the hollow cavity 40a of the first insulating member 40. This allows the phase change process of the phase change element 50 to absorb heat when the temperature of the battery cell 30 rises, reducing the risk of heat transfer from the battery cell 30 to adjacent battery cells 30 and thus preventing thermal runaway in those adjacent cells. This improves the thermal insulation between the battery cells 30, reduces the risk of thermal runaway propagating from one battery cell to another and causing wider thermal runaway, thereby enhancing the reliability of the battery cell 30. When the battery cell 30 is used in the battery device 10, the structure of the thermal insulation elements between the battery cells 30 can be omitted or simplified, reducing the assembly difficulty of the battery device 10 and improving its energy density.

[0120] In some embodiments, the phase change temperature T of the phase change element 50 satisfies: 80℃≤T≤120℃.

[0121] Optionally, the phase change temperature of the phase change element 50 can be 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃ or 120℃, etc.

[0122] It is understandable that when the temperature of a single battery cell 30 reaches 80℃, it can be determined that the single battery cell 30 has experienced thermal runaway. By setting the phase change temperature T of the phase change element 50 to satisfy 80℃≤T, it is beneficial to reduce the risk that the phase change element 50 will generate a phase change when the single battery cell 30 is working normally, but will not be able to generate a phase change and absorb heat in the event of thermal runaway of the single battery cell 30. By setting T≤120℃, it is beneficial for the phase change element 50 to generate a phase change and absorb heat in a timely manner in the event of thermal runaway of the single battery cell 30.

[0123] Therefore, after systematic analysis and long-term practice, the inventors discovered that by setting 80℃≤T≤120℃, it is beneficial to reduce the risk that the phase change element 50 will generate a phase change before the battery cell 30 thermally runs away, but will not be able to generate a phase change and absorb heat when the battery cell 30 thermally runs away. It also makes it easier for the phase change element 50 to generate a phase change and absorb heat in time during the process of thermal runaway of the battery cell 30, so as to reduce the risk of further spread of thermal runaway of the battery cell 30.

[0124] In some embodiments, such as Figure 5As shown, the first insulating member 40 includes a first clamping layer 41 and a second clamping layer 42. The peripheries of the first clamping layer 41 and the second clamping layer 42 are attached to each other and form a hollow cavity 40a. The phase change member 50 is clamped between the first clamping layer 41 and the second clamping layer 42.

[0125] In this way, the middle part of the first clamping layer 41 and the second clamping layer 42 can be separated from each other to form a hollow cavity 40a, while the peripheral parts are attached to each other to provide a certain sealing effect for the hollow cavity 40a and reduce the risk of loss of the phase change component 50.

[0126] Furthermore, by providing the first insulating member 40, which includes a first clamping layer 41 and a second clamping layer 42, it is also convenient for the first insulating member 40 to form a hollow cavity 40a, and for the phase change member 50 to fill the first hollow cavity 40a.

[0127] Therefore, this design simplifies the manufacturing process of the battery cell 30 and reduces the loss of the phase change element 50 in the hollow cavity 40a, which further improves the reliability of the battery cell 30.

[0128] In some embodiments, such as Figure 4 and Figure 6 As shown, the electrode assembly 32 includes an electrode body 321 and a tab 322. The tab 322 extends from the first end 321d of the electrode body 321 along a first direction X. The phase change element 50 is disposed on the side of the electrode body 321 along a second direction Y, which intersects the first direction X. The battery cell 30 also includes a second insulating element 60, which is disposed on the side of the housing 31 facing the tab 322. The first insulating element 40 and the second insulating element 60 are thermally fused together. Along the first direction X, the end of the phase change element 50 near the first end 321d and the end of the first insulating element 40 near the first end 321d have a first distance d, where d ≥ 5 mm.

[0129] The housing 31 may include a housing 311 and an end cap 312, with the end cap 312 covering the housing 311 to form a receiving cavity 31a. A second insulating member 60 may be provided on the side of the end cap 312 facing the tab 322 to achieve insulation between the electrode assembly 32 and the housing 31. The second insulating member 60 may be a structure such as lower plastic.

[0130] The first insulating member 40 and the second insulating member 60 are thermally fused together to improve the stability of the electrode assembly 32 structure and reduce the risk of the electrode assembly 32 shaking within the battery cell 30. The thermal fusion connection of the first insulating member 40 and the second insulating member 60 also provides good insulation for the electrode assembly 32 and the outer casing 31, reducing the risk of electrical connection between the electrode assembly 32 and the outer casing 31.

[0131] Optionally, d can be 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, etc.

[0132] It is understandable that the greater the distance d is to a certain extent, the easier it is to heat fuse the first insulating component 40 and the second insulating component 60, so as to reduce the manufacturing difficulty of the battery cell 30.

[0133] Therefore, after systematic analysis and long-term practice, the inventors found that by setting d≥5mm, it is easier to carry out the heat fusion connection between the first insulating component 40 and the second insulating component 60, which helps to reduce the process difficulty of the battery cell 30.

[0134] In some embodiments, such as Figure 6 As shown, the dimension of the first insulating member 40 along the first direction X is h, and 10% ≤ d / h ≤ 20%.

[0135] Optionally, d / h can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, etc.

[0136] It is understandable that a larger d / h value to a certain extent is more conducive to improving the convenience of thermal fusion connection between the first insulating component 40 and the second insulating component 60, while a smaller d / h value to a certain extent is more conducive to increasing the size of the phase change component 50 along the first direction X, so that the phase change component 50 can absorb more heat in the event of thermal runaway of the battery cell 30.

[0137] Therefore, after systematic analysis and long-term practice, the inventors discovered that by setting 10%≤d / h≤20%, the connection convenience of the first insulating component 40 and the second insulating component 60 is improved, while also increasing the space occupied by the phase change component 50 along the first direction X, so as to increase the heat absorption of the phase change component 50 during the phase change process in the event of thermal runaway of the battery cell 30.

[0138] In some embodiments, the material of the phase change element 50 includes paraffin wax or polyethylene wax.

[0139] The phase transition points of paraffin wax and polyethylene wax can be artificially adjusted, and both have high enthalpy values, allowing them to absorb more heat during the phase transition process. In addition, paraffin wax and polyethylene wax are inexpensive and have relatively stable performance during operation.

[0140] In some embodiments, such as Figure 4As shown, the electrode assembly 32 includes an electrode body 321 and a tab 322, with the tab 322 extending from the end of the electrode body 321 along a first direction X. The electrode body 321 includes two first surfaces 321a opposite each other along a second direction Y and two second surfaces 321b opposite each other along a third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. The two first surfaces 321a connect the two second surfaces 321b. The area of ​​the first surface 321a is larger than the area of ​​the second surface 321b. At least one first surface 321a has a phase change element 50 disposed on its side.

[0141] The first surface 321a is a surface with a large area of ​​the electrode body 321. During the thermal runaway of the battery cell 30, more of the heat of the electrode body 321 is transferred out through the first surface 321a. By providing a phase change element 50 on the side of at least one first surface 321a, the heat of the electrode assembly 32 can be absorbed by the phase change element 50 in time in the event of thermal runaway of the battery cell 30.

[0142] Optionally, the phase change element 50 may be provided on the side of only one of the first surfaces 321a, or the phase change element 50 may be provided on the side of both first surfaces 321a. The phase change element 50 may be provided only on the side of the first surface 321a, or the phase change element 50 may also be provided on the side of the second surface 321b or other surfaces of the electrode body 321.

[0143] In some embodiments, such as Figure 7 As shown, the dimensions of all electrode bodies 321 of a single battery cell 30 along the second direction Y are t1, the dimensions of the receiving cavity 31a along the second direction Y are t2, and the sum of the maximum dimensions of the first insulating member 40 and the phase change member 50 on the sides of the two first surfaces 321a along the second direction Y is e1, where e1≤0.93t2-t1.

[0144] It is understandable that phase change elements 50 can be provided on the sides of one or two first surfaces 321a, and first insulating elements 40 are provided on the sides of both first surfaces 321a. Therefore, when phase change elements 50 are provided on the sides of only one first surface 321a, e1 can be the sum of the thickness of the first insulating elements 40 on both sides of the electrode body 321 along the second direction Y and the thickest thickness of the phase change element 50 on one side. When phase change elements 50 are provided on the sides of both first surfaces 321a, e1 can be the sum of the thickness of the first insulating elements 40 on both sides of the electrode body 321 along the thickness direction and the thickest thickness of the phase change elements 50 on both sides.

[0145] t1 is the dimension of the electrode body 321 along the second direction Y. Optionally, the battery cell 30 may include one or more electrode bodies 321. When the battery cell 30 includes only one electrode assembly 32, t1 is the dimension of one electrode body 321 along the second direction Y. When the battery cell 30 includes multiple electrode assemblies 32 and the multiple electrode assemblies 32 are arranged along the second direction Y, t1 is the sum of the dimensions of the multiple electrode assemblies 32 arranged along the second direction Y.

[0146] Understandably, (e1+t1) / t2 represents the group margin of the battery cell 30. In practice, an excessively high group margin of the battery cell 30 may cause difficulties in assembling the battery cell 30 and poor wettability of the electrode assembly 32. Therefore, the group margin in the design of the battery cell 30 should not be too high. To this end, the inventors found in practice that the maximum group margin of the battery cell 30 is 93%. Therefore, 0.93t2-t1 represents the sum of the maximum dimensions of the first insulating member 40 and the phase change member 50 along the second direction Y when the group margin of the battery cell 30 is 0.93.

[0147] It is understandable that when the thickness of the phase change element 50 on both sides of the electrode assembly 32 along the second direction Y is the same, the thickness of the phase change element 50 on either side of the electrode assembly 32 along the second direction Y can be less than or equal to (e1+t1) / 2*t2.

[0148] Therefore, by setting e1≤0.93t2-t1, it is beneficial to control the group margin of the battery cell 30 to be less than or equal to 93%. This helps to reduce the risk of assembly difficulties due to excessive group margin of the battery cell 30 or poor wetting of the electrolyte to the electrode assembly 32.

[0149] In some embodiments, at least one side of the second surface 321b is provided with a phase change element 50.

[0150] Optionally, a phase change element 50 may be provided on the side of one of the second surfaces 321b, or a phase change element 50 may be provided on the sides of both second surfaces 321b. In other words, a phase change element 50 may be provided on one side of the electrode assembly 32 along the third direction Z, or a phase change element 50 may be provided on both sides of the battery cell 30 along the third direction Z.

[0151] Thus, in the event of thermal runaway in a single battery cell 30, the phase change element 50 on the side of the second surface 321b can also absorb some of the heat from the battery assembly, which helps to further improve the thermal insulation effect between the single battery cells 30 and reduce the risk of thermal runaway of a single battery cell 30 spreading to adjacent single battery cells 30.

[0152] In some embodiments, such as Figure 7As shown, the sum of the dimensions of the electrode body 321 along the third direction Z is t3, the dimension of the receiving cavity 31a along the third direction Z is t4, and the sum of the maximum dimensions of the first insulating member 40 and the phase change member 50 on the sides of the two second surfaces 321b along the third direction Z is e2, where e2≤t4-t3-1mm.

[0153] Since the phase change element 50 can be provided on the side of only one of the second surfaces 321b, or on the sides of both second surfaces 321b, and the sides of both second surfaces 321b are provided with the first insulating element 40, when the phase change element 50 is provided on the side of only one second surface 321b, e2 is the sum of the thicknesses of the two first insulating elements 40 on both sides of the two second surfaces 321b and the maximum thickness of the phase change element 50 on the side of one second surface 321b. When the phase change element 50 is provided on the sides of both second surfaces 321b, e2 is the sum of the thicknesses of the two first insulating elements 40 on the sides of the two second surfaces 321b and the maximum dimensions of the two phase change elements 50.

[0154] It is understandable that t4-t3-e2 represents the sum of the gaps between the first insulating member 40 and the housing 311 on both sides along the third direction Z during the insertion of the electrode assembly 32 into the housing. In practice, the inventors discovered that during the insertion of the electrode assembly 32 into the housing, the minimum gap that needs to be reserved between either side of the electrode assembly 32 along the third direction Z and the housing 311 is 0.5mm, in order to reduce the difficulty of inserting the electrode assembly 32 into the housing and to reduce the risk of the electrode assembly 32 being scratched during the insertion process.

[0155] Therefore, by setting e2≤t4-t3-1mm, it is easy to ensure that the sum of the gaps between the first insulating member 40 on both sides of the third direction Z and the housing 311 is at least 1mm during the process of inserting the electrode assembly 32 into the housing. This facilitates the assembly of the electrode assembly 32 into the housing 31 and reduces the risk of the electrode assembly 32 being scratched by the housing 311 during the process of inserting it into the housing.

[0156] It is understandable that, when the thickness of the phase change element 50 on both sides of the electrode assembly 32 along the third direction Z is the same, the subsequent thickness of the phase change element 50 on either side needs to be less than or equal to (t4-t3-1mm) / 2.

[0157] In some embodiments, such as Figure 4 As shown, the electrode body 321 also includes a third surface 321c, and the tab 322 is led out from the first end 321d of the electrode body 321. The third surface 321c is located on the side of the electrode body 321 opposite to the first end 321d. A phase change element 50 is provided on the side of the third surface 321c.

[0158] If a phase change element 50 is provided on the side of the third surface 321c, the heat of the battery cell 30 can also be absorbed by the phase change element 50 on the side of the third surface 321c. The phase change element 50 on the side of the third surface 321c absorbs the heat of the electrode assembly 32, further reducing the heat transferred from the battery cell 30 to other battery cells 30, and further reducing the risk of thermal runaway propagation of the battery cell 30.

[0159] It is understandable that phase change elements 50 can be provided on the sides of the two first surfaces 321a, the two second surfaces 321b, and the third surface 321c of the electrode assembly 32, so that more phase change elements 50 can absorb the heat of the battery cell 30, further improve the heat insulation effect between the battery cells 30, and reduce the risk of thermal runaway propagation of the battery cell 30.

[0160] In some embodiments, such as Figure 8 As shown, the first insulating member 40 on the side of the third surface 321c has a through hole 40b, which is disposed through the first insulating member 40 along the first direction X.

[0161] Optionally, the insulating component of the third surface 321c can have one, two, or more through holes 40b. By providing the first insulating component 40 with through holes 40b, during the production of the battery cell 30, after the electrolyte is injected into the casing 31, the electrolyte can penetrate into the electrode assembly 32 through the through holes 40b. This is beneficial to improving the wetting efficiency and wettability of the electrolyte on the electrode assembly 32, thereby improving the cycle performance of the battery cell 30.

[0162] It is understandable that, since the first insulating member 40 has a through hole 40b, and the phase change member 50 is disposed in the hollow cavity 40a of the first insulating member 40, the phase change member 50 and the through hole 40b are misaligned.

[0163] Secondly, the battery device 10 provided in the embodiments of this application includes the battery cell 30 provided in any of the above embodiments.

[0164] The battery device 10 provided in this application embodiment has the same technical effect as the battery cell 30 provided in any of the above embodiments, and will not be described again here.

[0165] In some embodiments, the electrode assembly 32 includes an electrode body 321 and tabs 322. The tabs 322 extend from the end of the electrode body 321 along a first direction X. Phase change elements 50 are disposed on both sides of the electrode body 321 along a second direction Y, where the first direction X intersects the second direction Y. The battery device 10 includes a plurality of battery cells 30, at least a portion of which are arranged along the second direction Y.

[0166] The first direction X intersects the second direction Y. For example, the first direction X can be perpendicular to the second direction Y.

[0167] Since the phase change element 50 is disposed on both sides of the electrode body 321 along the second direction Y, and multiple battery cells 30 are arranged along the second direction Y, there are two layers of phase change element 50 between the electrode assemblies 32 of any two adjacent battery cells 30. This is beneficial to further improve the heat insulation effect between battery cells 30, reduce the risk of thermal runaway of battery cells 30 spreading to each other, and further improve the reliability of the battery device 10.

[0168] Furthermore, since two phase change elements 50 are provided between the two electrode assemblies 32 of adjacent battery cells 30 along the second direction Y, the electrode assemblies 32 of the two adjacent battery cells 30 have a certain heat insulation effect through the two phase change elements 50. In this way, the heat insulation between the two adjacent battery cells 30 along the second direction Y can be thinned or omitted. Thus, by simplifying the overall structure of the battery device 10 and reducing the space occupied by the heat insulation between adjacent cells along the second direction Y, it is beneficial to improve the energy density of the battery device 10.

[0169] Optionally, the surface of the electrode assembly 32 along the second direction Y can be set to be the surface with the largest area of ​​the electrode assembly 32. This makes it easier to set more phase change elements 50 on the side of the electrode assembly 32 along the second direction Y, so as to maximize the heat absorption effect of the phase change elements 50 on themselves or adjacent battery cells 30.

[0170] In some implementations, two adjacent battery cells 30 along the second direction Y are bonded together.

[0171] Thus, the two adjacent battery cells 30 along the second direction Y are only insulated by the phase change element 50, without the need to set up heat insulation components or other structures between the battery cells 30. This is beneficial to simplify the structure of the battery device 10, simplify the assembly process of the battery device 10, and improve the energy density of the battery device 10.

[0172] Thirdly, the electrical device provided in the embodiments of this application includes the battery device 10 provided in the above embodiments, and the battery device 10 is used to provide electrical energy.

[0173] The electrical device provided in this application embodiment has the same technical effect as the battery device 10 provided in this application embodiment, and will not be described again here.

[0174] In some embodiments, such as Figures 4 to 8As shown, the battery cell 30 provided in this embodiment includes a shell 31, an electrode assembly 32, a first insulating member 40, a phase change member 50, and a second insulating member 60. The electrode assembly 32 is housed within a receiving cavity 31a. The first insulating member 40 covers the outer surface of the electrode assembly 32 and has a hollow cavity 40a. The phase change member 50 is disposed within the hollow cavity 40a and is configured to generate a phase change. The material of the phase change member 50 includes paraffin wax or polyethylene wax. The phase change temperature T of the phase change member 50 satisfies: 80℃ ≤ T ≤ 120℃. The first insulating member 40 includes a first clamping layer 41 and a second clamping layer 42. The peripheral sides of the first clamping layer 41 and the second clamping layer 42 are bonded together and surround to form the hollow cavity 40a. The phase change member 50 is sandwiched between the first clamping layer 41 and the second clamping layer 42. The electrode assembly 32 includes an electrode body 321 and a tab 322. The tab 322 extends from a first end 321d of the electrode body 321 along a first direction X. The electrode body 321 has two first surfaces 321a opposite each other along a second direction Y, two second surfaces 321b opposite each other along a third direction Z, and a third surface 321c. The two second surfaces 321b connect to the two third surfaces 321c. The third surface 321c is located on the side of the electrode body 321 opposite to the first end 321d along the first direction X. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. A phase change element 50 is located on the side of the two first surfaces 321a, the two second surfaces 321b, and the third surface 321c of the electrode body 321. A second insulating element 60 is located on the side of the housing 31 facing the tab 322. The first insulating element 40 and the second insulating element 60 are thermally fused together. The end of the phase change element 50 near the first end 321d along the first direction X has a first distance d with the end of the first insulating element 40 near the first end 321d, where d ≥ 5 mm. The dimension of the first insulating element 40 along the first direction X is h, where 10% ≤ d / h ≤ 20%. The dimension of the electrode body 321 along the second direction Y is t1, the dimension of the receiving cavity 31a along the second direction Y is t2, and the sum of the maximum dimensions of the first insulating element 40 and the phase change element 50 on the two sides of the first surface 321a along the second direction Y is e1, where e1 ≤ 0.93t2 - t1. The dimension of the electrode body 321 along the third direction Z is t3, the dimension of the receiving cavity 31a along the third direction Z is t4, and the sum of the maximum dimensions of the first insulating element 40 and the phase change element 50 on the two sides of the second surface 321b along the third direction Z is e2, where e2 ≤ t4 - t3 - 1 mm. The first insulating member 40 on the side of the third surface 321c has a through hole 40b, which is disposed through the first insulating member 40 along the first direction X.

[0175] The battery cell 30 provided in this embodiment incorporates a phase change element 50 within the hollow cavity 40a of the first insulating member 40. This allows the phase change process of the phase change element 50 to absorb heat when the temperature of the battery cell 30 rises, reducing the risk of heat transfer from the battery cell 30 to adjacent battery cells 30 and thus preventing thermal runaway in those adjacent cells. This improves the thermal insulation between the battery cells 30, reduces the risk of thermal runaway propagating from one battery cell to another and causing wider thermal runaway, thereby enhancing the reliability of the battery cell 30. When the battery cell 30 is used in the battery device 10, the structure of the thermal insulation elements between the battery cells 30 can be omitted or simplified, reducing the assembly difficulty of the battery device 10 and improving its energy density.

[0176] 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 battery cell, characterized by, include: The outer shell has a receiving cavity; The electrode assembly is housed within the receiving cavity; A first insulating element covers the outer surface of the electrode assembly, and the first insulating element has a hollow cavity; A phase change element is disposed within the hollow cavity, and the phase change element is configured to generate a phase change.

2. The battery cell of claim 1, wherein, The phase transition temperature T of the phase change element satisfies: 80℃≤T≤120℃.

3. The battery cell of claim 1, wherein, The first insulating element includes a first clamping layer and a second clamping layer, the peripheries of the first clamping layer and the second clamping layer are attached to each other and surround to form the hollow cavity, and the phase change element is clamped between the first clamping layer and the second clamping layer.

4. The battery cell of claim 1, wherein, The electrode assembly includes an electrode body and a tab. The tab extends from a first end of the electrode body along a first direction. The phase change element is disposed on the side of the electrode body along a second direction, which intersects with the first direction. The battery cell further includes a second insulating component, which is disposed on the side of the outer casing facing the tab, and the first insulating component and the second insulating component are thermally fused together. Along the first direction, the end of the phase change element near the first end and the end of the first insulating element near the first end have a first distance d, where d ≥ 5 mm.

5. The battery cell of claim 4, wherein, The dimension of the first insulating element along the first direction is h, and 10% ≤ d / h ≤ 20%.

6. The battery cell of claim 1, wherein, The material of the phase change element includes paraffin wax or polyethylene wax.

7. The battery cell of any one of claims 1 to 6, wherein, The electrode assembly includes an electrode body and a tab, the tab being extended from the end of the electrode body along a first direction; The electrode body includes two first surfaces opposite each other along a second direction and two second surfaces opposite each other along a third direction. The first direction, the second direction, and the third direction are perpendicular to each other. The two first surfaces connect to the two second surfaces. The area of ​​the first surface is larger than the area of ​​the second surface. The phase change element is disposed on the side of at least one of the first surfaces.

8. The battery cell of claim 7, wherein, The electrode body has a dimension of t1 along the second direction, the receiving cavity has a dimension of t2 along the second direction, and the sum of the maximum dimensions of the first insulating member and the phase change member on the two first surface sides along the second direction is e1, where e1 ≤ 0.93t2-t1.

9. The battery cell of claim 7, wherein, At least one side of the second surface is provided with a phase change element.

10. The battery cell of claim 9, wherein, The electrode body has a dimension of t3 along the third direction, the receiving cavity has a dimension of t4 along the third direction, and the sum of the maximum dimensions of the first insulating member and the phase change member on the two second surface sides along the third direction is e2, where e2≤t4-t3-1mm.

11. The battery cell according to claim 7, characterized in that, The electrode body further includes a third surface, and the tab extends from the first end of the electrode body. The third surface is located on the side of the electrode body opposite to the first end. The phase change element is disposed on the side of the third surface.

12. The battery cell of claim 11, wherein, The first insulating member on the third surface side has a through hole, which is disposed through the first insulating member along the first direction.

13. A battery device characterized by comprising: Includes the battery cell as described in any one of claims 1 to 12.

14. The battery device of claim 13, wherein, The electrode assembly includes an electrode body and tabs. The tabs are led out from the end of the electrode body along a first direction. The phase change element is disposed on both sides of the electrode body along a second direction, where the first direction intersects the second direction. The battery device includes a plurality of battery cells, at least a portion of which are arranged along the second direction.

15. The battery device of claim 14, wherein, Two adjacent battery cells along the second direction are bonded together.

16. An electrical device, comprising: Includes the battery device as described in claim 14 or 15, the battery device being used to provide electrical energy.

Images