Battery monomer, battery device, electric equipment and energy storage device

Abstract

The utility model provides a battery monomer, a battery device, electric equipment and an energy storage device, and belongs to the field of batteries. The battery monomer comprises an electrode component and a shell, the electrode component comprises an electrode assembly accommodated in the shell, the shell comprises a shell body and a compressible layer which are matched in shape, the compressible layer is fixedly connected with the inner circumferential side face of the shell body, and a gap is formed between the inner circumferential side face of the compressible layer and the outer circumferential wall face of the electrode component. The gap is used for absorbing the expanded part of the electrode component, and the compressible layer can insulate and isolate the peripheral wall surface of the electrode component from the shell side wall of the shell body. At the initial stage of the cycle stage of the battery monomer, the gap absorbs partial expansion of the electrode part until the electrode part is expanded to be in contact with the compressible layer, and the compressible layer provides good support for the electrode part by utilizing the elastic deformation characteristic of the compressible layer, so that the deformation of the electrode plate is reduced, the electrode plate wrinkling phenomenon caused by the expansion of the electrode assembly can be improved, and the service life of the battery is prolonged. And the use reliability of the single battery is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery monomer, a battery device, an electric equipment and an energy storage device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] During the use of the battery monomer in charging and discharging, the electrode assembly is prone to swelling and deformation, which causes the electrode tab of the electrode assembly to be prone to wrinkling, thereby causing a series of problems and affecting the use reliability of the battery monomer. CONTENT OF THE UTILITY MODEL

[0004] The present application aims to at least solve one of the technical problems in the background art. To this end, one object of the present application is to provide a battery monomer, a battery device, an electric equipment and an energy storage device to improve the wrinkling phenomenon of the electrode tab caused by the swelling of the electrode assembly, thereby improving the use reliability and safety of the battery monomer.

[0005] Embodiments of the first aspect of the present application provide a battery monomer, comprising an electrode component and a shell, the electrode component comprising one electrode assembly or a plurality of electrode assemblies stacked along the thickness direction thereof; the shell having a receiving cavity for accommodating the electrode component; the shell comprising a shell body and a compressible layer, the compressible layer being fixedly connected to the inner circumferential surface of the shell body, a gap being formed between the inner circumferential surface of the compressible layer and the outer circumferential wall of the electrode component, the gap being used to absorb part of the swelling of the electrode component, and the compressible layer being further configured to insulate the outer circumferential wall of the electrode component from the shell side wall of the shell body.

[0006] In the present application, at the initial stage of the cycle stage of the battery monomer, the gap can absorb part of the swelling of the electrode component, and after the electrode component swells to contact the compressible layer, the electrode component continues to swell, and the compressible layer provides good support to the electrode component, which is beneficial to reducing the deformation of the electrode tab, thereby improving the wrinkling phenomenon of the electrode tab caused by the swelling of the electrode assembly, reducing the risk of lithium precipitation, and improving the use reliability and safety of the battery monomer.

[0007] In some embodiments, the thickness D1 of the electrode component accounts for more than or equal to 85% and less than 100% of the width D2 of the receiving cavity in the thickness direction of the electrode assembly.

[0008] In this embodiment, by designing D1 to occupy less than 100% of D2, D1 is smaller than D2, making it easier for electrode components to be inserted into the casing during battery cell assembly, thus reliably forming a gap. In this embodiment, by designing D1 to occupy not less than 85% of D2, the gap width is controlled to prevent it from being too large, allowing the compressible layer to reliably provide support for the electrode components.

[0009] In some embodiments, along the thickness direction of the electrode assembly, the electrode component has two large surfaces facing away from each other; the compressible layer includes two large surface areas, which are located on opposite sides of the electrode component along the thickness direction of the electrode assembly, and each large surface area is opposite to and parallel to one of the large surfaces; the sum of the thicknesses D3 of the two large surface areas accounts for a percentage of the minimum vertical distance D4 of the shell body in the thickness direction of the electrode assembly that is greater than or equal to 0.5% and less than or equal to 12%.

[0010] This embodiment achieves a good balance between the gap and the compressible layer's support for the electrode assembly, thus ensuring both easy insertion of the electrode components into the housing and stable support of the electrode components by the compressible layer in the early stages of the cycling phase.

[0011] In some embodiments, the compressible layer is configured such that its compressibility under a first preset pressure condition is less than or equal to 50%, and the compressible layer is configured such that its compressibility under a second preset pressure condition is greater than 50% and less than 95%; wherein the first preset pressure is less than the second preset pressure.

[0012] In this embodiment, the compressibility of the compressible layer increases with the increase of the internal pressure of the housing, so that the expansion force of the compressible layer and the electrode components can be matched throughout their entire life cycle.

[0013] In some embodiments, the first preset pressure P1 satisfies: 0MPa < P1 < 0.8MPa, and the second preset pressure P2 satisfies: P2 ≥ 1MPa.

[0014] In some embodiments, the compressible layer is bonded to the inner peripheral side of the shell body via an adhesive layer. Using adhesive bonding, the shell body can be a monolithic structure, the assembly process is simple, and because adhesive bonding is suitable for combining different materials, the material restrictions on the compressible layer can be relaxed; the compressible layer can be made not only of plastic or rubber, but also of sponge.

[0015] In some embodiments, the compressible layer is thermally fused to the inner peripheral side of the shell body. This thermal fusion connection method allows for rapid and secure connection between the compressible layer and the inner peripheral side of the shell body.

[0016] In some embodiments, the compressible layer is deposited on the inner peripheral side of the shell body using a material deposition molding process. By employing this process, the compressible layer and the shell sidewall of the shell body are integrated, resulting in strong adhesion and tight connection between the compressible layer and the inner peripheral side of the shell body, which improves the reliability of their connection.

[0017] In some embodiments, the housing further includes an insulating layer disposed on the side of the bottom plate of the housing body facing the electrode component, and the insulating layer can insulate and isolate the bottom wall surface of the electrode component from the bottom plate of the housing body.

[0018] This embodiment provides insulation protection for the surface of the bottom plate of the casing with an insulating layer, reducing the risk of short circuits in individual battery cells caused by electrical connection between the bottom wall of the electrode components and the bottom plate of the casing body, thereby improving the electrical safety of electrical equipment and energy storage devices.

[0019] In some embodiments, the battery cell further includes an electrolyte disposed within a receiving cavity; a one-way conduction portion is provided inside the compressible layer, the one-way conduction portion having a one-way flow channel, the liquid inlet end of the one-way flow channel being exposed at the bottom end of the compressible layer, the liquid outlet end of the one-way flow channel being exposed at the top end of the compressible layer, the one-way conduction portion being able to automatically drive the electrolyte to flow along the one-way flow channel, and the electrolyte flowing out from the liquid outlet end of the one-way flow channel being able to flow to the top end of the electrode component.

[0020] In this embodiment, the unidirectional guide section can guide the electrolyte at the bottom of the receiving cavity to the top of the electrode component, thereby improving the wetting effect at the top of the electrode component.

[0021] In some embodiments, the unidirectional flow portion is a Tesla valve, or the unidirectional flow portion is a through-hole whose shape is configured to be the same as the flow channel shape of the Tesla valve.

[0022] In some embodiments, a plurality of unidirectional conductive sections are spaced apart within the compressible layer along the circumference of the housing. This embodiment provides multiple unidirectional conductive sections, thereby enhancing the electrolyte delivery capacity and further improving the wetting effect on the electrode components.

[0023] In some embodiments, the compressible layer is made of rubber or plastic.

[0024] An embodiment of the second aspect of this application provides a battery device that includes the battery cell described in the above embodiments.

[0025] An embodiment of the third aspect of this application provides an electrical device that includes a single battery cell as described in the above embodiments, or that includes a battery device as described in the above embodiments.

[0026] An embodiment of the fourth aspect of this application provides an energy storage device that includes a single battery cell as described in the above embodiments, or that includes a battery device as described in the above embodiments.

[0027] 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

[0028] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0029] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0030] Figure 2 This is an exploded view of the battery device according to some embodiments of this application;

[0031] Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0032] Figure 4 for Figure 3 The diagram shows a cross-sectional view of a single battery cell when the electrode components are not in an expanded state.

[0033] Figure 5 for Figure 3 The diagram shows a cross-sectional view of a single battery cell when the electrode components are in an expanded state.

[0034] Figure 6 for Figure 3 The image shows a cross-sectional view of the compressible layers of a single battery cell.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1000 vehicles;

[0037] Battery unit 100, controller 200, motor 300;

[0038] Battery cell assembly 10, battery cell 11, housing 110, housing body 111, compressible layer 112, large surface area 1121, unidirectional conduction part 1122, electrode component 120, electrode assembly 121, large surface 122, receiving cavity 130, end cap 140.

[0039] Box 20, first box 21, second box 22. Detailed Implementation

[0040] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0042] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0043] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0044] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0045] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0046] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0047] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation", "connection", "linking", and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components.

[0048] In this application, the term "parallel" includes not only absolute parallelism but also approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only absolute perpendicularity but also approximate perpendicularity as commonly understood in engineering. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0049] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0050] As positive and negative electrode active materials insert or extract ions during charge-discharge cycles, the electrode assembly tends to expand outward. During this expansion, the electrode sheets deform under the influence of expansion forces. However, uneven distribution of these forces leads to wrinkling of the electrode sheets, especially on the largest surface area. The largest surface area refers to the sidewall of the electrode sheet with the largest surface area. If wrinkling occurs, the volume change in the wrinkled area can cause localized electrolyte insufficiency, leading to electrolyte breakage. Furthermore, the lithium ion insertion / extraction process in this area will deteriorate, resulting in lithium plating and affecting the reliability of the battery cell.

[0051] To mitigate the problem of electrode wrinkling caused by electrode assembly expansion, some existing technologies incorporate two buffer components between the electrode assembly and the casing of the battery cell. These two buffer components are tightly attached to two large surfaces of the electrode assembly. While these buffer components provide support and cushioning for the electrode assembly, to ensure insulation between the electrode assembly and the casing and prevent short circuits, the two buffer components must be stacked together with the electrode assembly during assembly, and then covered with a Mylar membrane. This means the two buffer components and the Mylar membrane contact opposite sides of the electrode assembly in the thickness direction. This requires space for both the buffer components and the Mylar membrane, affecting the energy density of the battery cell. Furthermore, this type of battery cell requires the installation of both the buffer components and the Mylar membrane during assembly, resulting in multiple assembly steps.

[0052] Based on the above considerations, a battery cell was designed. The sidewall of the casing includes a casing body and a compressible layer. The compressible layer is fixedly connected to the inner circumferential side of the casing body. The compressible layer also insulates and isolates the outer circumferential wall of the electrode components from the sidewall of the casing body. In this battery cell, the compressible layer, as part of the casing, integrates the functions of the Mylar membrane and the buffer, essentially improving the Mylar membrane in related technologies into a compressible layer to absorb and buffer the expansion of the electrode components, thus eliminating the need for an additional buffer. The compressible layer requires less space and eliminates the assembly steps of the Mylar membrane and buffer, reducing the number of assembly steps in the battery cell and improving assembly efficiency.

[0053] The battery devices described in this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft, as well as in energy storage devices. A power system for such electrical equipment can be constructed using battery cells and battery devices as described in this application. Similarly, a power system for such energy storage devices can be constructed using battery cells and battery devices as described in this application.

[0054] The energy storage device utilizing a battery as a power system in this application embodiment can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems, etc. The energy storage device can store electrical energy as needed and output it at appropriate times. For example, the energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. The energy storage device provided in this application embodiment can be used in any power system that requires energy storage.

[0055] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0056] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters housed within the cabinet. Each battery cluster may include multiple battery units connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, these clusters are connected in parallel to increase the capacity of the energy storage device.

[0057] In this application embodiment, the electrical devices using battery devices as power sources can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0058] It should be understood that the technical solutions described in the embodiments of this application are not limited to the battery devices and electrical equipment described above, but can also be applied to all battery devices including housings and electrical equipment using battery devices. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0059] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 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. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is provided 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. 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, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0060] 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.

[0061] Figure 2 The structure of a battery device 100 according to an embodiment of this application is shown. Figure 2As shown, the battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies 10 for providing voltage and capacity. The battery cell assembly 10 may include multiple battery cells 11, which are connected in series, parallel, or mixed connection via a busbar.

[0062] In some embodiments, the battery cell assembly 10 is typically formed by arranging a plurality of battery cells 11.

[0063] As an example, the battery cell assembly 10 can be a battery module, which is formed by arranging and fixing multiple battery cells 11 together to form an independent module. As an example, the battery module can be formed by bundling multiple battery cells 11 together with cable ties.

[0064] In some embodiments, such as Figure 2 As shown, the battery device 100 can be a battery pack, which includes a housing 20 and one or more individual battery cells 10, with the individual battery cells 10 housed within the housing 20. The housing 20 can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of combinations of simple cuboids, cylinders, or spheres. The material of the housing 20 can be an alloy such as aluminum alloy or iron alloy, a polymer such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin.

[0065] As an example, the battery cell assembly 10 can be a battery module, and the battery cell assembly 10 can be housed in the housing 20 by fixing the battery module in the housing 20.

[0066] As an example, the battery cell assembly 10 can also be housed in the housing 20 by directly fixing multiple battery cells 11 to the housing 20.

[0067] As an example, the housing 20 may include a first housing 21 and a second housing 22. The first housing 21 and the second housing 22 are fastened together to form a closed space inside the housing 20 to house the battery cell assembly 10. Here, "closed" refers to covering or closing, and can be either non-sealed or sealed to prevent liquids or other foreign objects from affecting the charging or discharging of the battery cell 11. The first housing 21 may be a top cover or a bottom plate.

[0068] As an example, the housing 20 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 20 forms an enclosed space to accommodate the battery cell assembly 10.

[0069] In some embodiments, the housing 20 may be part of the vehicle's chassis structure. For example, a portion of the housing 20 may be at least a portion of the vehicle's floor, or a portion of the housing 20 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0070] The battery cell 11 provided in the embodiments of this application can be a secondary battery. A secondary battery refers to a battery cell 11 that can be used again after being discharged by recharging to activate the active material.

[0071] The battery cell 11 can be a 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., and this application embodiment is not limited to this. As an example, the battery cell 11 can be a prismatic battery cell, a blade-shaped battery cell, or a multi-prism battery cell, such as a hexagonal prism battery cell, etc., and this application has no particular limitation.

[0072] Figure 3 The exploded structure of a battery cell according to some embodiments of this application is shown. For example... Figure 3 As shown, the battery cell 11 provided in the embodiments of this application includes a casing, an electrode component 120, and an electrolyte, with the electrode component 120 and the electrolyte housed within the casing. As an example, the electrolyte may be liquid, gel-like, or solid. The electrode component 120 includes one or more electrode assemblies 121, which are components in the battery cell 11 where electrochemical reactions occur. As an example, the electrode component 120 may include multiple electrode assemblies 121, which are stacked along their own thickness direction.

[0073] The electrode assembly 121 includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell 11, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrode. The separator is disposed between the positive and negative electrode to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0074] The electrode assembly 121 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked. In some embodiments, the electrode assembly 121 is a wound structure. The positive and negative electrode sheets are wound into a wound structure. In some embodiments, the electrode assembly 121 is a stacked structure. As an example, multiple positive and negative electrode sheets can be provided, with multiple positive and multiple negative electrode sheets alternately stacked. As an example, multiple positive electrode sheets can be provided, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments. As an example, both positive and negative electrode sheets are folded to form multiple stacked folded segments. As an example, multiple spacers can be provided, respectively disposed between any adjacent positive or negative electrode sheets. As an example, spacers can be continuously provided, disposed between any adjacent positive or negative electrode sheets by folding or winding. In some embodiments, the shape of the electrode assembly 121 can be flat or polygonal, etc. In some embodiments, the electrode assembly 121 is provided with tabs that can conduct current from the electrode assembly 121. The tabs include a positive tab and a negative tab.

[0075] As an example, the outer casing can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc. Figure 3 As shown, the outer casing specifically includes a housing 110 and an end cap 140. The end cap 140 covers the opening of the housing 110, and the housing 110 and the end cap 140 together enclose a space for encapsulating the electrode component 120 and other components such as the electrolyte.

[0076] End cap 140 refers to a component that covers the opening of housing 110 to isolate the internal environment of battery cell 11 from the external environment. The shape of end cap 140 can be adapted to the shape of housing 110 to fit it. Optionally, end cap 140 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 140 is not easily deformed under pressure or impact, giving battery cell 11 higher structural strength and improved safety performance. Functional components such as electrode assembly terminals can be provided on end cap 140. Electrode assembly terminals can be used for electrical connection with electrode components to output or input electrical energy to battery cell 11.

[0077] As an example, the end cap 140 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 11 reaches a threshold. The end cap 140 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0078] Figure 4 It shows Figure 3 The image shows a cross-section of the battery cell 11 when the electrode component 120 is not in an expanded state. Please refer to...Figure 3 and Figure 4 The housing 110 has a receiving cavity 130 for accommodating the electrode component 120. The housing 110 includes a shell body 111 with a matching shape and a compressible layer 112. The compressible layer 112 is fixedly connected to the inner peripheral side surface of the shell body 111. A gap is formed between the inner peripheral side surface of the compressible layer 112 and the outer peripheral wall surface of the electrode component 120. The gap is used to absorb the expansion portion of the electrode component 120. The compressible layer 112 is also configured to insulate and isolate the outer peripheral wall surface of the electrode component 120 from the shell side wall of the shell body 111.

[0079] The shell body 111 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. The shell body 111 can have various shapes and sizes, which can be determined according to the specific shape and size of the electrode assembly 121. For example, in Figure 3 In the example shown, the battery cell 11 is a prismatic battery cell 11, the electrode assembly 121 is flat, and the shell body 111 and the compressible layer 112 are both cuboid in shape. For ease of description, the thickness direction of the electrode assembly 121 is shown as the front-to-back direction in the accompanying drawings, the length direction of the electrode assembly 121 is shown as the left-to-right direction, and the height direction of the electrode assembly 121 and the shell 110 is shown as the up-down direction. Figure 3 and Figure 4 Along the thickness direction of the electrode assembly 121, the electrode component 120 has two large surfaces 122 facing away from each other, and the inner peripheral side surface of the compressible layer 112 has a first surface and a second surface facing away from each other. The first surface is opposite to and parallel to one of the large surfaces 122, and the second surface is opposite to and parallel to the other large surface 122.

[0080] The compressible layer 112 is made of an elastic insulating material, allowing it to deform elastically and thus achieve compressibility. For example, the material of the compressible layer 112 can be any of sponge, rubber, or plastic. Rubber can be, but is not limited to, silicone rubber, fluororubber, ethylene propylene rubber, etc., and plastic can be, but is not limited to, polyurethane (PU), polytetrafluoroethylene (PTFE), polyimide, polycarbonate, etc. When the electrode component 120 is not in an expanded state, a gap is formed between the inner peripheral side of the compressible layer 112 and the outer peripheral wall of the electrode component 120. This indicates that the outer peripheral wall of the electrode component 120 is not in contact with the compressible layer 112 when it is not expanded. The gap is used to absorb the expansion of the electrode component 120, meaning the width of the gap is less than the expansion deformation of the electrode component 120. Therefore, when the electrode component 120 is not in an expanded state, the thickness D1 of the electrode component 120 is less than the width D2 of the receiving cavity 130 in the thickness direction of the electrode assembly 121. It is understood that the inner peripheral side of the compressible layer 112 and the bottom wall of the shell body 111 together form a receiving cavity 130, and the width D2 of the receiving cavity 130 in the thickness direction of the electrode assembly 121 is the vertical distance between the first and second surfaces of the compressible layer 112.

[0081] The assembly process of the battery cell 11 in this embodiment is as follows: S11, the shell body 111 and the compressible layer 112 are connected to preform the shell 110; S12, an electrode component 120 is provided and inserted into the receiving cavity 130 of the shell 110 through the opening; S13, the end cap 140 is connected to the shell 110 to close the opening.

[0082] Figure 5 It shows Figure 3 The cross-section of the battery cell 11 shown is displayed when the electrode component 120 is in an expanded state. The working principle of the battery cell 11 in this embodiment is roughly as follows: In the initial state, as... Figure 4 As shown, the electrode component 120 is not in an expanded state, and there is a gap between the outer peripheral wall of the electrode component 120 and the compressible layer 112; in the initial stage of the cycle phase of the battery cell 11, the electrode component 120 gradually expands, and the width of the gap gradually decreases until the outer peripheral wall of the electrode component 120 expands to abut against the inner peripheral side of the compressible layer 112, as shown. Figure 5As shown, the battery cell 11 continues to undergo charge and discharge cycles, and the electrode component 120 continues to expand to compress the compressible layer 112. That is, the expansion force of the electrode component 120 acts on the compressible layer 112. During this process, since the compressible layer 112 abuts against the outer peripheral wall of the electrode component 120, the compressible layer 112 can support the electrode component 120. In the later stage of the battery cell 11 cycle, the compressibility of the compressible layer 112 increases to continue to absorb the expansion force, and the volume of the compressible layer 112 decreases. Then, the volume of the receiving cavity 130 increases, so that the gas released by the electrode component 120 has sufficient emission space.

[0083] In this embodiment, the housing 110 is designed to include a housing body 111 with a matching shape and a compressible layer 112. The compressible layer 112 is fixedly connected to the inner peripheral side of the housing body 111, and the compressible layer 112 can insulate and isolate the outer peripheral wall of the electrode component 120 from the side wall of the housing body 111. This allows the compressible layer 112 to integrate the characteristics of a buffer and a Mylar membrane in related technologies. Compared with related technologies that simultaneously provide a buffer and a Mylar membrane, the compressible layer 112 requires less space without changing parameters such as size, thus reserving more space to accommodate the electrolyte, which is beneficial to improving the energy density of the battery cell 11. By integrating the buffer and Mylar membrane in the compressible layer 112, the assembly process of the buffer and Mylar membrane can be eliminated, thus reducing the assembly process and improving the assembly efficiency of the battery cell 11, and shortening the production cycle.

[0084] This embodiment also incorporates a gap between the inner peripheral side of the compressible layer 112 and the outer peripheral wall of the electrode component 120. This facilitates the insertion of the electrode component 120 into the housing 110 during battery cell assembly, reducing the likelihood of damage to the electrode component 120 due to friction with the housing 110 during insertion. This ensures stable installation of the electrode component 120 within the housing 110 and enhances the reliability of the assembled battery cell 11. Furthermore, in the initial stages of battery cell 11 cycling, the gap absorbs the expansion of the electrode component 120. Once the electrode component 120 expands to contact the compressible layer 112, the elastic deformation characteristics of the compressible layer 112 provide excellent support for the electrode component 120 as it continues to expand. This reduces electrode deformation and mitigates wrinkling caused by the expansion of the electrode assembly 121, thus reducing the risk of lithium plating and ultimately improving the reliability of the battery cell 11.

[0085] Thanks to the fixed connection between the compressible layer 112 and the inner circumferential side of the shell body 111, the connection between the compressible layer 112 and the shell body 111 is reliable, reducing the possibility of the compressible layer 112 shaking during transportation or when the battery cell 11 is impacted.

[0086] According to some embodiments of this application, the percentage of the thickness D1 of the electrode component 120 to the width D2 of the receiving cavity 130 in the thickness direction of the electrode assembly 121 can be designed to be greater than or equal to 85% and less than 100%.

[0087] That is, 85% ≤ D1 ÷ D2 × 100% < 100%, which means 0.85 ≤ D1 / D2 < 1, so D1 < D2.

[0088] The thickness of a single electrode assembly 121 can range from [22.5mm, 26.5mm], specifically 22.5mm, 23.5mm, 24.5mm, 25.5mm, or 26.5mm. The thickness of the shell body 111 can be uniform throughout, and can range from [0.4mm, 0.8mm], specifically 0.4mm, 0.5mm, 0.6mm, 0.7mm, or 0.8mm.

[0089] In this embodiment, by designing that D1 accounts for less than 100% of D2, the thickness D1 of the electrode component 120 during battery cell 11 assembly is less than the width D2 of the receiving cavity 130 in the thickness direction of the electrode assembly 121. This facilitates the easy insertion of the electrode component 120 into the casing during battery cell 11 assembly, enabling reliable gap formation. Furthermore, by designing that D1 accounts for no less than 85% of D2, this embodiment results in a smaller gap width. This allows the initial expansion and deformation of the electrode assembly 121 during the initial cycling phase of the battery cell 11 to exceed the gap width. This ensures that, during the initial cycling phase of the battery cell 11, after the expansion and deformation of the electrode component 120 exceeds the gap width, the compressible layer 112 can reliably provide support for the electrode component 120.

[0090] According to some embodiments of this application, in an embodiment where the electrode assembly 121 is flat and the shell body 111 and compressible layer 112 are cuboid, the compressible layer 112 specifically includes two large surface areas 1121, which are located on opposite sides of the electrode component 120 along the thickness direction of the electrode assembly 121. Each large surface area 1121 is opposite to and parallel to a large surface 122. Furthermore, under the condition that 85% ≤ D1 ÷ D2 × 100% < 100%, the percentage of the sum of the thicknesses D3 of the two large surface areas 1121 to the minimum vertical distance D4 of the shell body 111 in the thickness direction of the electrode assembly 121 can be further designed to be greater than or equal to 0.5% and less than or equal to 12%.

[0091] That is, the internal space of the shell body 111 has a dimension D4 in the thickness direction of the electrode assembly 121. D4 can be greater than or equal to 53 mm and less than or equal to 57 mm, specifically 53 mm, 54 mm, 55 mm, 56 mm or 57 mm. Based on the above, it can be understood that D1 + 2 × D3 < D4, D2 = D4 - 2 × D3.

[0092] Taking D4 as 55mm and the thickness of a single electrode assembly 121 as 24.5mm as an example, D3 in this example satisfies: 0.1375mm≤D3<3mm. The specific value of D3 and related data can be found in Table 1.

[0093] Table 1

[0094]

[0095] This embodiment is designed in such a way that the gap and the compressible layer 112’s support capacity for the electrode assembly 121 can be well balanced. This ensures that the electrode component 120 is easy to insert into the housing and that the electrode component 120 is stably supported by the compressible layer 112 in the early stage of the cycle.

[0096] Specifically, on the one hand, since the sum of the thicknesses D3 of the two large areas 1121 accounts for less than or equal to 12% of the minimum vertical distance D4 of the shell body 111 in the thickness direction of the electrode assembly 121, the thickness D3 of the large areas 1121 will not be too large, so as to provide sufficient gap for the battery cell 11 in the initial state, so as to facilitate the easy insertion of the electrode component 120 into the shell during assembly, and to facilitate the gap to absorb part of the expansion in the early stage of the cycling phase. On the other hand, since the sum of the thicknesses D3 of the two large areas 1121 accounts for more than or equal to 0.5% of the minimum vertical distance D4 of the shell body 111 in the thickness direction of the electrode assembly 121, the thickness D3 of the large areas 1121 will not be too small, so as to ensure that the compressible layer 112 can provide support for the expanded electrode assembly 121.

[0097] According to some embodiments of this application, the compressible layer 112 can be configured such that its compressibility under a first preset pressure P1 is less than or equal to 50%, and the compressible layer 112 can be configured such that its compressibility under a second preset pressure P2 is greater than 50% and less than 95%. Wherein, the first preset pressure P1 < the second preset pressure P2.

[0098] The compressibility of the compressible layer 112 refers to its ability to shrink in volume when subjected to the expansion force of the electrode component 120, reflecting its ability to deform along the direction of the expansion force. The preset pressure can be a preset value set based on the expansion force of the electrode component 120 and the gas pressure inside the housing 110. Under the first preset pressure P1, the compressibility of the compressible layer 112 can be any value among 41%, 45%, and 49%. Under the second preset pressure P2, the compressibility of the compressible layer 112 can be any value among 51%, 55%, 61%, 65%, 70%, 75%, 80%, 85%, and 91%.

[0099] This embodiment is designed so that the compressibility of the compressible layer 112 increases with the increase of the internal pressure of the housing 110. During the charge and discharge cycle of the battery cell 11, the electrode component 120 continuously expands, and the volume of the receiving cavity 130 gradually decreases. As a result, the internal pressure of the housing 110 gradually increases. Thanks to the fact that the compressibility of the compressible layer 112 increases with the increase of the internal pressure of the housing 110, the compressible layer 112 can match the expansion force of the electrode component 120 throughout its entire life cycle. This effectively absorbs the expansion force of the electrode component 120, improves the wrinkling phenomenon of the electrode sheet, and thus improves the reliability of the battery cell 11.

[0100] According to some embodiments of this application, the first preset pressure P1 can be designed as: 0MPa < P1 < 0.8MPa, and the second preset pressure P2 can be designed as: P2 ≥ 1MPa.

[0101] The first preset pressure P1 can be any value among 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa, 0.5MPa, 0.6MPa, and 0.7MPa, and the second preset pressure P2 can be any value among 1MPa, 1.5MPa, 2MPa, and 2.5MPa.

[0102] It is understandable that, as disclosed in this paper, there are various ways to achieve the fixed connection between the compressible layer 112 and the inner circumferential side of the shell body 111 in the battery cell 11. Specifically, the connection can be achieved by an adhesive bonding process or by a material deposition molding process. The following describes several possible methods.

[0103] According to some embodiments of this application, the compressible layer 112 can be bonded to the inner peripheral side of the shell body 111 by an adhesive layer.

[0104] The adhesive layer can be made of, but is not limited to, any one of polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), or polyvinylpyrrolidone (PVP).

[0105] The specific implementation process of step S11 in this example may include the following steps: S21, providing a shell body 111 and a compressible layer 112; S22, applying adhesive to the inner peripheral side of the shell body 111 and / or the outer peripheral side of the compressible layer 112; S23, inserting the compressible layer 112 into the internal space of the shell body 111 from one end; S24, drying the adhesive to form an adhesive layer using techniques such as natural air drying or baking. S22 can be achieved using adhesive application processes such as dot coating, brush coating, spray coating, roller coating, or dip coating.

[0106] According to some embodiments of this application, the compressible layer 112 may also be replaced by a thermally fused connection to the inner peripheral side of the shell body 111.

[0107] In this example, the compressible layer 112 can be made of plastic or rubber. Taking a cuboid shell 110 as an example, a specific implementation of step S11 in this example may include the following steps S31 to S33. S31: Provide four wall panels and four compressible sheets, and press each pre-made compressible sheet onto the surface of a wall panel by high temperature and pressure, so that the compressible sheet is thermally fused to the corresponding wall panel; S32: Connect the four wall panels end to end to form the shell sidewall of the shell body 111, at this time the four wall panels are the opposite front wall panel and rear wall panel, and the opposite left wall panel and right wall panel; S33: Provide a shell bottom plate, and connect the shell bottom plate to the shell sidewall to form the shell 110.

[0108] Alternatively, another specific implementation of step S11 in this example may include the following steps S41 to S44. S41: A flat plate and a compressible sheet are provided. The pre-made compressible sheet is laminated onto the surface of the flat plate by high temperature and pressure, so that the compressible sheet and the flat plate are thermally fused together; S42: The component obtained in S41 is bent into a cuboid shape through multiple bends; S43: The ends of the component obtained in S42 are welded together. This step can obtain the shell sidewall of the shell body 111, wherein the compressible layer 112 is formed by bending the compressible sheet through multiple bends; S44: A shell bottom plate is provided, and the shell bottom plate is connected to the shell sidewall obtained in S43 to form the shell 110.

[0109] According to some embodiments of this application, the compressible layer 112 may also be replaced by being deposited on the inner peripheral side of the shell body 111 by a material deposition molding process.

[0110] In this example, the compressible layer 112 can be made of plastic or rubber. The material deposition molding process can be, but is not limited to, spraying, dip coating, 3D printing, electrophoretic deposition, chemical deposition, and casting.

[0111] Taking a cuboid shell 110 as an example, a specific implementation of step S11 in this example may include the following steps S51 to S53. S51: Provide four wall panels, and directly print elastic material layers on the surfaces of the four wall panels using a 3D printing process; S52: Connect the four wall panels end to end to form the shell sidewalls of the shell body 111. At this time, the four wall panels are opposite front wall panels and rear wall panels, and opposite left wall panels and right wall panels. This step can obtain the shell sidewalls of the shell body 111, wherein the compressible layer 112 is composed of the elastic material layers on each wall panel; S53: Provide a shell bottom plate, and connect the shell bottom plate to the shell sidewalls obtained in S52 to form the shell 110.

[0112] Alternatively, another specific implementation of step S11 in this example may include the following steps S61 to S64. S61: Provide a flat plate, and directly pour liquid elastic material onto the surface of the plate using a casting process and solidify it, so that an elastic material layer is formed on the surface of the plate; S62: Bend the component obtained in S61 into a cuboid shape through multiple bends; S63: Weld the ends of the component obtained in S62 together, and this step yields the shell sidewall of the shell body 111, wherein the compressible layer 112 is formed by multiple bends of the elastic material layer; S64: Provide a shell bottom plate, and connect the shell bottom plate to the shell sidewall obtained in S63 to form the shell 110.

[0113] By comparison, it can be seen that in the technical solution of bonding the compressible layer 112 to the inner peripheral side of the shell body 111, the shell body 111 can be an integral structure, the assembly process is simple, and since the bonding process is suitable for combining different materials, the material restrictions on the compressible layer 112 can be relaxed. The material of the compressible layer 112 can be not only plastic or rubber, but also sponge. In the technical solution of heat-melting the compressible layer 112 to the inner peripheral side of the shell body 111, the connection and fixation of the compressible layer 112 and the inner peripheral side of the shell body 111 can be quickly achieved. In the technical solution of directly depositing the compressible layer 112 onto the inner peripheral side of the shell body 111, the compressible layer 112 and the shell sidewall of the shell body 111 are an integral part, and the bonding force of the compressible layer 112 and the inner peripheral side of the shell body 111 are strong and the connection is tight, which helps to improve the connection reliability of the two.

[0114] Figure 6 for Figure 3 The diagram shows a cross-sectional view of the compressible layer 112 of the battery cell 11. Based on some embodiments of this application, where the electrolyte is a liquid electrolyte, as... Figure 6As shown, a one-way conduction section 1122 may be further provided inside the compressible layer 112. The one-way conduction section 1122 has a one-way flow channel. The liquid inlet end of the one-way flow channel is exposed at the bottom end of the compressible layer 112, and the liquid outlet end of the one-way flow channel is exposed at the top end of the compressible layer 112. The one-way conduction section 1122 can automatically drive the electrolyte to flow along the one-way flow channel, and the electrolyte flowing out from the liquid outlet end of the one-way flow channel can flow to the top end of the electrode component 120.

[0115] The unidirectional guide section 1122 is configured to drive the electrolyte to flow along the unidirectional flow channel without external force. In this embodiment, the installation position relationship between the compressible layer 112 and the shell body 111 should satisfy the following: the bottom end of the compressible layer 112 is spaced a certain distance from the bottom plate of the shell body 111, so that the liquid inlet end of the unidirectional flow channel is not blocked by the bottom plate, allowing liquid to enter the unidirectional flow channel. In this embodiment, the installation position relationship between the compressible layer 112 and the electrode component 120 should satisfy the following: the top end of the compressible layer 112 is close to the top surface of the electrode component 120, so that the electrolyte flowing out from the liquid outlet end of the unidirectional flow channel can flow to the top end of the electrode component 120. Specifically, the top end face of the compressible layer 112 can be flush with the top surface of the electrode component 120, or the top end face of the compressible layer 112 can be slightly lower than the top surface of the electrode component 120, or the top end face of the compressible layer 112 can be slightly higher than the top surface of the electrode component 120.

[0116] By providing a one-way conduction section 1122, the electrolyte at the bottom of the receiving cavity 130 can be guided to the top of the electrode component 120, which can improve the wetting effect at the top of the electrode component 120 and facilitate the electrode component 120 to be fully wetted, thus having a positive effect on reducing the risk of lithium plating on the electrode component 120.

[0117] The one-way conduction unit 1122 can be implemented in various ways. According to some embodiments of this application, the one-way conduction unit 1122 can be a Tesla valve.

[0118] The shape of the Tesla valve is not limited and can be a hollow three-dimensional cylinder, a square hollow column, a polygonal hollow column, etc. Optionally, the orifice diameter of the Tesla valve can be greater than or equal to 0.01 mm and less than or equal to 2 mm, for example, 0.01 mm, 0.1 mm, 0.2 mm, 0.5 mm, 1 mm, 1.5 mm or 2 mm.

[0119] In this example, the compressible layer 112 can be designed to be formed by stacking and mating a first layer and a second layer. The second layer is located outside the first layer. The side of the first layer facing the second layer has a first half-groove, and the side of the second layer facing the first layer has a second half-groove. When the first layer and the second layer are mated, the first half-groove and the second half-groove are mated to form a mounting groove. The shape of the mounting groove matches the shape of the Tesla valve for installation of the Tesla valve. Specifically, when preparing the housing 110, the process of pre-preparing the compressible layer 112 before providing it can be as follows: providing the first layer and the Tesla valve, and partially embedding the Tesla valve into the first half-groove; providing the second layer, and installing the second layer outside the first layer and mating the two together.

[0120] According to some other embodiments of this application, the unidirectional guide portion 1122 can be replaced with a through hole, the shape of which is configured to be the same as the flow channel shape of the Tesla valve, so that the through hole can perform the unidirectional drive function of the Tesla valve.

[0121] Referring to the Tesla valve technical solution with unidirectional conduction part 1122 as reference, in this example, the compressible layer 112 can also be designed to be formed by stacking and docking a first layer and a second layer, with the second layer located outside the first layer. A first half-groove is formed on the side of the first layer facing the second layer, and a second half-groove is formed on the side of the second layer facing the first layer. The difference lies in the fact that in the Tesla valve technical solution with unidirectional conduction part 1122, the first half-groove and the second half-groove dock to form a mounting groove for installing the Tesla valve, while in the through-hole technical solution with unidirectional conduction part 1122, the through-hole is formed by docking the first half-groove and the second half-groove.

[0122] Based on some embodiments of this application, please continue to refer to Figure 6 Along the circumference of the housing 110, multiple unidirectional conduction sections 1122 may be distributed at intervals inside the compressible layer 112.

[0123] Optionally, the normal distance d between two adjacent unidirectional conduction parts 1122 can satisfy: 0.2mm≤d≤10mm. The number of unidirectional conduction parts 1122 can be, but is not limited to, 2, 3, 4 or more, and can be designed according to the working conditions and actual needs.

[0124] In this embodiment, multiple unidirectional conduction sections 1122 are provided, which enhances the electrolyte delivery capability, enabling sufficient electrolyte to be delivered to the top of the electrode component 120. This further improves the wetting effect of the electrode component 120, thereby reducing the risk of lithium plating on the electrode component 120.

[0125] According to some embodiments of this application, the housing 110 may further include an insulating layer disposed on the side of the bottom plate of the housing body 111 facing the electrode component 120. The insulating layer can insulate and isolate the bottom wall surface of the electrode component 120 from the bottom plate of the housing body 111.

[0126] The insulating layer can be an insulating film bonded to the surface of the shell bottom plate or an insulating coating (e.g., insulating varnish) applied to the surface of the shell bottom plate. The material of the insulating layer can be polytetrafluoroethylene, polyethylene, etc. The thickness of the insulating layer is not limited; it is optional, and the thickness range can be greater than or equal to 5 μm and less than or equal to 1 mm. Further, the thickness range can be greater than or equal to 100 μm and less than or equal to 200 μm, specifically 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, or 200 μm.

[0127] This embodiment provides insulation protection for the surface of the bottom plate of the casing with an insulating layer, reducing the risk of short circuit in the battery cell 11 caused by electrical connection between the bottom wall of the electrode component 120 and the bottom plate of the casing body 111, thereby improving the electrical safety of electrical equipment and energy storage devices.

[0128] 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.

[0129] In one specific embodiment of this application, such as Figures 3 to 5 As shown, the battery cell 11 includes a housing 110 and an electrode component 120 and an electrolyte disposed within a receiving cavity 130 of the housing 110. The electrode component 120 includes two flat electrode assemblies 121, which are stacked along their thickness direction. The thickness of the electrode assembly 121 is 24.5 mm, and the thickness D1 of the electrode component 120 is 49 mm. The front wall surface of the front electrode assembly 121 and the rear wall surface of the rear electrode assembly 121 are both large surfaces 122. An insulating layer is formed on the surface of the bottom plate of the housing 110 facing the receiving cavity 130 by spraying. This insulating layer effectively insulates and isolates the bottom wall surface of the electrode component 120 from the bottom plate of the housing body 111. The shell sidewall of the housing 110 includes a cuboid shell body 111 and a compressible layer 112. The compressible layer 112 is bonded to the inner peripheral side of the shell body 111 by an adhesive layer. The internal space of the shell body 111 has a dimension D4 of 55 mm in the thickness direction of the electrode assembly 121. The compressible layer 112 includes two large surface areas 1121 arranged opposite to each other. Each large surface area 1121 is opposite to and parallel to a large surface 122. The thickness D3 of the large surface area 1121 is 2 mm. Therefore, D1 + 2 × D3 < D4, which creates a gap between the inner peripheral side of the compressible layer 112 and the outer peripheral wall of the electrode assembly 120.

[0130] Specifically, the sum of the thicknesses D3 of the two large surface areas 1121 accounts for 7.3% of the internal space of the shell body 111 in the thickness direction of the electrode assembly 121 dimension D4. The width D2 of the receiving cavity 130 in the thickness direction of the electrode assembly 121 (i.e., the vertical distance between the two large surface areas 1121) is 51 mm. The thickness of the electrode component 120 accounts for 96.1% of the width D2 of the receiving cavity 130 in the thickness direction of the electrode assembly 121. The sum of the thickness of the electrode component 120 and the thicknesses D3 of the two large surface areas 1121 accounts for 96.3% of the internal space of the shell body 111 in the thickness direction of the electrode assembly 121 dimension D4.

[0131] The compressibility of the compressible layer 112 under the first preset pressure P1 is less than or equal to 50%, where 0 MPa < P1 < 0.8 MPa. The compressibility of the compressible layer 112 under the second preset pressure P2 is greater than 50% and less than 95%, where P2 ≥ 1 MPa.

[0132] like Figure 6 As shown, multiple Tesla valves are spaced apart inside the compressible layer 112 along the circumference of the housing 110. Each Tesla valve has a unidirectional flow channel, which automatically drives the electrolyte to flow along the channel, allowing the electrolyte at the bottom of the receiving cavity 130 to flow out from the outlet end of the unidirectional flow channel and be delivered to the top of the electrode component 120. The orifice diameter of the Tesla valve is greater than or equal to 0.01 mm and less than or equal to 2 mm. The vertical distance between two adjacent unidirectional guide sections 1122 is greater than or equal to 0.2 mm and less than or equal to 10 mm.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. 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, The application relates to a battery cell. The battery cell comprises: an electrode component, which comprises an electrode assembly or a plurality of electrode assemblies stacked along the thickness direction of the electrode assembly; 2. The battery cell of claim 1, wherein, a shell, which has a receiving cavity for accommodating the electrode component; the shell comprises a shell body and a compressible layer, the compressible layer is fixedly connected to the inner circumferential surface of the shell body, a gap is formed between the inner circumferential surface of the compressible layer and the outer circumferential wall surface of the electrode component, the gap is used for absorbing the expansion of the electrode component, and the compressible layer is configured to insulate the outer circumferential wall surface of the electrode component and the shell side wall of the shell body.

3. The battery cell of claim 2, wherein, The thickness D1 of the electrode component accounts for more than or equal to 85% and less than 100% of the width D2 of the receiving cavity in the thickness direction of the electrode assembly. The electrode component has two opposite large surfaces in the thickness direction of the electrode assembly; the compressible layer comprises two large surface areas, which are respectively located on the two sides of the electrode component in the thickness direction of the electrode assembly, and each large surface area is opposite to and parallel to one large surface; 4. The battery cell according to any one of claims 1 to 3, characterized in that, The sum of the thicknesses D3 of the two large surface areas accounts for more than or equal to 0.5% and less than or equal to 12% of the minimum vertical distance D4 of the shell body in the thickness direction of the electrode assembly. The compressible rate of the compressible layer under a first preset pressure condition is less than or equal to 50%, and the compressible rate of the compressible layer under a second preset pressure condition is more than 50% and less than 95%; 5. The battery cell of claim 4, wherein, The first preset pressure is less than the second preset pressure.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The first preset pressure P1 satisfies 0MPa < P1 < 0.8MPa, and the second preset pressure P2 satisfies P2 >= 1MPa. The compressible layer is bonded to the inner circumferential surface of the shell body through an adhesive layer; Alternatively, the compressible layer is hot-melt connected to the inner circumferential surface of the shell body; 7. The battery cell according to any one of claims 1 to 6, characterized in that, Alternatively, the compressible layer is deposited on the inner circumferential surface of the shell body through a material deposition forming process.

8. The battery cell of any one of claims 1 to 7, wherein, The shell further comprises an insulating layer, which is arranged on the side of the shell bottom plate of the shell body facing the electrode component, and the insulating layer can insulate the bottom wall surface of the electrode component and the shell bottom plate of the shell body. The battery cell further comprises electrolyte, which is arranged in the receiving cavity; 9. The battery cell of claim 8, wherein, The compressible layer is internally provided with a one-way conduction part, which has a one-way flow channel, the liquid inlet end of the one-way flow channel is exposed to the bottom end of the compressible layer, the liquid outlet end of the one-way flow channel is exposed to the top end of the compressible layer, the one-way conduction part can automatically drive the electrolyte to flow along the one-way flow channel, and the electrolyte flowing out of the liquid outlet end of the one-way flow channel can flow to the top end of the electrode component.

10. The battery cell according to claim 8 or 9, characterized in that The one-way conduction part is a Tesla valve, or the one-way conduction part is a conduction hole, and the shape of the conduction hole is configured to be the same as the shape of the flow channel of the Tesla valve.

11. The battery cell of any one of claims 1 to 10, wherein, A plurality of one-way conduction parts are internally and intervally distributed in the compressible layer along the circumferential direction of the shell.

12. A battery device characterized by comprising: The material of the compressible layer is selected from rubber or plastic. The application further relates to a battery pack comprising the battery cell as claimed in any one of claims 1 to 11.

13. An electrical device, characterized by The power consuming device includes the battery cell according to any one of claims 1 to 11, or the power consuming device includes the battery device according to claim 12.

14. An energy storage device, characterized by, The energy storage device includes the battery cell according to any one of claims 1 to 11, or the energy storage device includes the battery device according to claim 12.

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