Battery device, electric device, and buffer member

Abstract

The application discloses a battery device, a power utilization device and a buffer, and belongs to the technical field of batteries. The battery device comprises a box body, a battery monomer and a buffer, the box body is provided with a containing cavity; the battery monomer is arranged in the containing cavity; and the buffer is arranged in the containing cavity. The buffer comprises a buffer main body and a pressure balance part. The buffer main body is attached to one side surface of the battery monomer. The buffer main body comprises a film layer and a buffer medium. The film layer defines a buffer space. The buffer medium is contained in the buffer space. The pressure balance part defines a containing space. The containing space is communicated with the buffer space. The buffer is configured in such a manner that at least part of the buffer medium is adaptively transferred between the buffer space and the containing space according to the deformation of the battery monomer. In this way, the pressure borne by the battery monomer can be maintained within a smaller range, the risk of damage of the battery monomer is reduced, and the use reliability of the battery device is improved.

Description

Technical Field

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

[0002] In related technologies, battery cells undergo volume changes during charging and discharging, and adjacent battery cells may experience localized mutual compression, leading to stress concentration, which increases the risk of damage to battery cells and reduces the reliability of the battery device.

[0003] Application content

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, one object of this application is to provide a battery device that has a lower risk of damage to individual battery cells and higher reliability in use.

[0005] This application further proposes an electrical device employing the aforementioned battery device.

[0006] This application further proposes a buffer for the aforementioned battery device.

[0007] In a first aspect, embodiments of this application provide a battery device, the battery device comprising: a housing having a receiving cavity; a battery cell disposed in the receiving cavity; and a buffer member disposed in the receiving cavity, the buffer member comprising a buffer body and a pressure balancing portion, the buffer body being fitted to one side surface of the battery cell, the buffer body comprising a film layer and a buffer medium, the film layer defining a buffer space, the buffer medium being accommodated in the buffer space, the pressure balancing portion defining the receiving space, and the receiving space communicating with the buffer space; the buffer member is configured such that at least a portion of the buffer medium adaptively shifts between the buffer space and the receiving space according to the deformation of the battery cell.

[0008] In the above technical solution, by setting a buffer component that adheres to one side surface of the battery cell, during the expansion of the battery cell leading to increased volume, the battery cell compresses the buffer body, increasing the pressure between the battery cell and the buffer body. The buffer medium within the buffer body is compressed and transferred into the receiving space, thus preventing excessive pressure increase between the battery cell and the buffer body, i.e., the pressure on the battery cell is not excessive. Conversely, during the contraction of the battery cell after expansion, the pressure exerted by the battery cell on the buffer body decreases, and the buffer medium in the receiving space flows back into the buffer space, preventing excessive pressure decrease between the battery cell and the buffer body. Therefore, by setting up the buffer component, the pressure on the battery cell can be kept within a small range, i.e., neither too high nor too low. Furthermore, the overall structure of the buffer component in this application is simple, low-cost, and easy to use. Additionally, due to the flowability of the buffer medium and the flexibility of the film layer, a good fit can be maintained between the surface of the battery cell and the buffer body, resulting in more uniform stress on the battery cell and reducing the risk of stress concentration.

[0009] In some embodiments, the pressure balancing part includes: a housing having a columnar cavity, the housing being connected to the membrane layer; a slider disposed in the cavity and in contact with the sidewall of the cavity, the slider dividing the cavity into a first chamber and a second chamber arranged along its length; wherein the accommodating space includes the second chamber, and the slider slides along the length of the cavity under the pressure difference between the first chamber and the second chamber to change the volume of the second chamber.

[0010] In the above technical solution, by setting a pressure balancing part including a housing and a sliding member, the pressure on the battery cell from the buffer body can be kept within a small range. Meanwhile, the buffer in this application does not require an additional driving component, reducing energy consumption, and features a simple structure, easy arrangement, long service life, and low operating cost.

[0011] In some embodiments, the buffer further includes a connecting tube that connects between the membrane and the housing and communicates with the second chamber and the buffer space.

[0012] In the above technical solution, the setting of the connecting pipe allows the housing to be arranged in a suitable position according to the usage and design requirements, or allows for more freedom in the size design of the housing, which facilitates the efficient use of space; at the same time, it can also reduce the possibility of interference between the housing and the peripheral components of the battery cell.

[0013] In some embodiments, the pressure balancing portion includes an elastic membrane with an elastic coefficient less than that of the membrane layer. The elastic membrane defines the accommodating space and is deformable under the action of the buffer medium to change the volume of the accommodating space.

[0014] In the above technical solution, the pressure balancing section includes an elastic membrane. Utilizing the stretchable nature of the elastic membrane, the volume of the accommodating space can change according to the pressure exerted by the battery cell on the buffer body, reducing the possibility of excessive or insufficient pressure on the battery cell and ensuring optimal performance. Furthermore, by rationally positioning the elastic membrane, the buffer medium can enter a suitable spatial location after the buffer body is compressed, resulting in a simpler and more integrated structure for the pressure balancing section.

[0015] In some embodiments, the elastic membrane is integrally formed with the membrane layer.

[0016] In the above technical solution, there are no seams between the elastic membrane and the membrane layer, and the integration of the elastic membrane and the membrane layer is better, which helps to make the overall airtightness of the buffer better and less prone to cracks and damage.

[0017] In some embodiments, the initial pressure range of the buffer space is 0.1 MPa to 20 MPa.

[0018] In the above technical solutions, pressure changes may affect the internal pore structure of the electrode material inside the battery cell and its contact area with the electrolyte. Appropriate external pressure helps to improve the contact between the electrode material and the electrolyte, reduce interfacial resistance, and thus improve battery performance. Therefore, by adjusting the pressure in the buffer space, the battery cell can be made to operate within a suitable pressure range to obtain better performance.

[0019] In some embodiments, the initial pressure range of the buffer space is 0.1 MPa to 3.5 MPa.

[0020] In the above technical solutions, pressure changes may affect the internal pore structure of the electrode material inside the battery cell and its contact area with the electrolyte. Appropriate external pressure helps to improve the contact between the electrode material and the electrolyte, reduce interfacial resistance, and thus improve battery performance. Therefore, by adjusting the pressure in the buffer space, the battery cell can be made to operate within a suitable pressure range to obtain better performance.

[0021] In some embodiments, the membrane layer includes a reinforcing membrane layer, which may include a prestressed membrane layer or a composite material membrane layer.

[0022] In the above technical solution, the reinforcing film is flexible and can fit well with the surface of the battery cell. It is also not prone to elastic deformation, so that the buffer medium can be squeezed into the containment space when the pressure of the buffer space increases. When the buffer space is under the initial pressure, the reinforcing film will not undergo uncontrollable large elastic deformation and can maintain the required shape and volume. This is beneficial to improving the performance consistency of multiple battery devices and reducing the possibility of the buffer component affecting other structures in the battery device.

[0023] In some embodiments, the buffer body further includes a heat-resistant layer, the heat-resistant layer and the film layer are stacked, the heat-resistant layer is located on the side of the film layer facing away from the buffer medium, and is attached to one side surface of the battery cell.

[0024] In the above technical solution, the heat-resistant layer can make the film layer have good environmental adaptability. For example, when the ambient temperature is too high or too low, or when the temperature of the battery cell is high, the film layer of the buffer body is not easily damaged and the buffer medium is not easily leaked. This helps to reduce the safety risks of the buffer component.

[0025] In some embodiments, the buffer medium is configured such that it undergoes a phase change to become liquid when the battery cell reaches a set temperature.

[0026] In the above technical solution, the buffer medium undergoes a phase change when it reaches the set temperature. Therefore, it can efficiently remove the heat generated by the battery cell while the temperature of the buffer medium itself remains unchanged or does not increase significantly, thereby reducing the possibility of overheating of the battery cell and enabling the battery cell to have better performance.

[0027] In some embodiments, the set temperature is greater than or equal to the upper limit of the operating temperature of the battery cell.

[0028] In the above technical solution, once the temperature of the battery cell reaches or exceeds the upper limit of the battery cell's operating temperature, the buffer medium will undergo a phase change and absorb heat to reduce the rate of temperature rise of the battery cell, reduce the risk of overheating of the battery cell, and reduce the risk of accelerated aging and thermal runaway of the battery cell.

[0029] In some embodiments, the set temperature is 40°C to 60°C.

[0030] In the above technical solution, the set temperature is within this range, which allows the buffer medium to efficiently absorb a large amount of heat, preventing the battery cells from heating up too quickly, and also allows the buffer to be used in most environments.

[0031] In some embodiments, the buffer medium is configured such that a phase transition occurs when the battery cell reaches a set temperature, changing it from a gel state to a liquid state.

[0032] In the above technical solution, the buffer medium is in a gel state below the set temperature, which improves the uniformity and stability of the buffer medium.

[0033] In some embodiments, the battery device includes a plurality of battery cell assemblies, each battery cell assembly including a plurality of battery cells; in at least one of the buffers, the number of buffer bodies is plurality of and at least a portion of the buffer bodies are connected to the same pressure balancing part, and a plurality of battery cells in at least one battery cell assembly are fitted together with a plurality of buffer bodies of one buffer.

[0034] In the above technical solutions, the buffer can adapt to different usage scenarios, and the arrangement of the buffer can be more flexible.

[0035] In some embodiments, the battery device includes a plurality of battery cells, and in at least one buffer member, the number of buffer bodies is plurality of and at least two buffer bodies are connected to the same pressure balancing part, and the plurality of battery cells are fitted together with a plurality of buffer bodies of a buffer member.

[0036] In the above technical solutions, the buffer can adapt to different usage scenarios, and the arrangement of the buffer can be more flexible.

[0037] In some embodiments, the battery device includes a plurality of battery cells, and the buffer includes a plurality of buffer bodies and a plurality of pressure balancing parts, wherein the plurality of buffer bodies and the plurality of pressure balancing parts are connected in a one-to-one correspondence, and one battery cell is fitted to one buffer body.

[0038] In the above technical solutions, the buffer can adapt to different usage scenarios, and the arrangement of the buffer can be more flexible.

[0039] In some embodiments, the battery device includes a plurality of battery cell assemblies arranged along a first direction, each battery cell assembly including a plurality of battery cells arranged along a second direction, the first direction and the second direction intersecting; the battery cells are in contact with the buffer body at least on two sides along the second direction.

[0040] In the above technical solution, the contact area between the battery cell and the buffer body is large, and the heat exchange effect between the buffer body and the battery cell is good.

[0041] In some embodiments, the housing includes a bottom wall and a peripheral wall connected to the circumferential edge of the bottom wall; a buffer body is provided between two adjacent battery cells, and / or, the buffer body is provided between the battery cell and the peripheral wall, and / or, the buffer body is provided between the battery cell and / or a beam in the housing; the pressure balancing part is located between the peripheral wall and the battery cell.

[0042] In the above technical solution, the pressure balancing part can be arranged between the peripheral wall and the battery cell, that is, arranged in the reserved side impact space, so that no additional reserved space is needed to accommodate the pressure balancing part, which is beneficial to increasing the space utilization efficiency of the battery device.

[0043] In some embodiments, the battery device further includes a heat exchanger, wherein the battery cell includes an intersecting first wall and a second wall, the first wall is fitted to the buffer body, and the heat exchanger is fitted to the second wall and is used for heat exchange with the battery cell.

[0044] In the above technical solution, the heat exchanger and the buffer are respectively attached to different walls of the battery cell, so that the heat exchanger can directly exchange heat with the battery cell and will not exchange heat with the buffer. This reduces the possibility that the buffer absorbs the energy of the heat exchanger, which is conducive to the efficient utilization of the energy of the heat exchanger, so that the heat exchanger can quickly cool and quickly heat the battery cell.

[0045] Secondly, this application provides an electrical device, including the aforementioned battery device, which is used to store or provide electrical energy.

[0046] Thirdly, this application provides a buffer for a battery device, the battery device including a battery cell, the buffer comprising:

[0047] A buffer body is used to adhere to one side surface of the battery cell. The buffer body includes a film layer and a buffer medium. The film layer defines a buffer space, and the buffer medium is accommodated in the buffer space.

[0048] A pressure balancing section defines a receiving space, which is connected to the buffer space;

[0049] The buffer is configured such that at least a portion of the buffer medium adaptively shifts between the buffer space and the containment space according to the deformation of the battery cell.

[0050] In the above technical solution, by setting a buffer component that adheres to one side surface of the battery cell, during the expansion of the battery cell leading to increased volume, the battery cell compresses the buffer body, increasing the pressure between the battery cell and the buffer body. The buffer medium within the buffer body is compressed and transferred into the receiving space, thus preventing excessive pressure increase between the battery cell and the buffer body, i.e., the pressure on the battery cell is not excessive. Conversely, during the contraction of the battery cell after expansion, the pressure exerted by the battery cell on the buffer body decreases, and the buffer medium in the receiving space flows back into the buffer space, preventing excessive pressure decrease between the battery cell and the buffer body. Therefore, by setting up the buffer component, the pressure on the battery cell can be kept within a small range, i.e., neither too high nor too low. Furthermore, the overall structure of the buffer component in this application is simple, low-cost, and easy to use. Additionally, due to the flowability of the buffer medium and the flexibility of the film layer, a good fit can be maintained between the surface of the battery cell and the buffer body, resulting in more uniform stress on the battery cell and reducing the risk of stress concentration.

[0051] 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

[0052] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0053] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0054] Figure 3 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0055] Figure 4 This is a schematic diagram of the structure of multiple buffers provided in some embodiments of this application;

[0056] Figure 5 A top view of a battery cell and a buffer provided in some embodiments of this application;

[0057] Figure 6 for Figure 4 A magnified view of part A in the middle;

[0058] Figure 7 This is a schematic diagram of the structure of a single buffer provided in some embodiments of this application;

[0059] Figure 8 for Figure 7 A partially enlarged sectional view of section B.

[0060] Figure label:

[0061] 1000 vehicles;

[0062] Battery device 100; controller 200; motor 300;

[0063] Box 10;

[0064] First housing 101; Second housing 102; Receiving cavity 103; Bottom wall 104;

[0065] Peripheral wall 105; Top wall 106;

[0066] 20 battery cells;

[0067] Buffer 30;

[0068] Buffer body 301; membrane layer 3011; buffer medium 3012; buffer space 3013;

[0069] Reinforcing membrane layer 3014; heat-resistant layer 3015; pressure balancing part 302; accommodating space 3021;

[0070] Housing 3022; Sliding member 3023; First chamber 3024; Second chamber 3025;

[0071] Connecting pipe 303; First direction F1; Second direction F2;

[0072] Length direction F. Detailed Implementation

[0073] 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 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.

[0074] 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.

[0075] In this application, the reference to "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 in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0076] 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.

[0077] 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.

[0078] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0079] In this application, "multiple" means two or more (including two).

[0080] Currently, battery devices are being used more and more widely. They are not only applied in various power systems such as hydropower, thermal power, wind power, and solar power plants, but also in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment, aerospace, and many other fields. As the application areas of battery devices continue to expand, their market demand is also constantly increasing.

[0081] A single battery cell can be a rechargeable battery. A rechargeable battery is a battery cell that can be recharged after it has been discharged, allowing the active materials to be activated and the cell to continue to be used.

[0082] The battery cell 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 the embodiments of this application are not limited to this.

[0083] 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.

[0084] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0085] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0086] 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.

[0087] 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.

[0088] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0089] As an example, the enclosure may include a first enclosure and a second enclosure, which are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or shutting down; it can be sealed or not sealed. The first enclosure may be a top cover or a bottom plate.

[0090] As an example, the enclosure may include a top cover, a frame, and a bottom plate, with the top cover and bottom plate connected to the frame respectively, so that the interior of the enclosure forms a closed space to house the individual battery cells.

[0091] 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.

[0092] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, or solid-state batteries, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0093] A single battery cell includes a casing, electrode components, and an electrolyte (which may be a solid electrolyte layer located between the positive and negative electrodes in a solid-state battery). The electrode components include at least one electrode assembly, and both the electrode assembly and the electrolyte are housed within the casing. The electrode assembly includes a positive electrode, a negative electrode, and a separator (this structure can be omitted in solid-state batteries). The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes.

[0094] The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the positive current collector without the positive active material layer protrudes from the positive current collector with the positive active material layer. The positive current collector without the positive active material layer serves as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.

[0095] The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the negative current collector without the negative active material layer protrudes from the negative current collector with the negative active material layer. The negative current collector without the negative active material layer serves as a negative electrode tab. The material of the negative current collector can be copper, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP, polypropylene, PE, polyethylene, etc. The electrode assembly mentioned in the embodiments of this application has a wound or stacked structure.

[0096] The electrode assembly can be a wound structure or a stacked structure. During processing, the positive electrode sheet, negative electrode sheet, and separator are wound or stacked in sequence to obtain the electrode assembly. In the electrode assembly, multiple positive electrode tabs are stacked together and form an electrical connection with the positive electrode post assembly, and multiple negative electrode tabs are stacked together and form an electrical connection with the negative electrode post assembly.

[0097] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical devices that use battery devices.

[0098] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0099] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0100] Please refer to Figure 1 , Figure 1 The diagram below illustrates the structure of a vehicle 1000 according to some embodiments of this application. The vehicle 1000 is equipped with a battery device 100, which may 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.

[0101] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0102] 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.

[0103] Please refer to Figure 2 , Figure 2 The image shows an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a battery cell 20 and a housing 10 for housing the battery cell 20. The housing 10 can have various structural forms.

[0104] In some embodiments, the housing 10 may include a first housing 101 and a second housing 102, which cover each other, and together define a receiving cavity for accommodating the battery cell 20. A sealing element may also be provided at the connection point between the first housing 101 and the second housing 102 to achieve a sealed connection between them. For example, refer to... Figure 2 The first box 101 and the second box 102 can both be hollow structures with an opening on one side. The opening side of the first box 101 covers the opening side of the second box 102, thus forming a box 10 with a storage space. Alternatively, the second box 102 can be a hollow structure with an opening on one side, and the first box 101 can be a lid that covers the opening side of the second box 102. The box 10 can have various shapes, such as a cylindrical box, a cuboid box, etc.

[0105] A single battery cell experiences significant expansion force during charging and discharging. To optimize the performance of a single battery cell, it is necessary to provide a relatively constant constraint force during the charging and discharging process.

[0106] In related technologies, to prevent excessive pressure fluctuations on individual battery cells during the entire charging and discharging process, an integrated testing fixture is typically used. The battery cells are placed inside the fixture, with adjacent cells separated by separators. The fixture incorporates pressure sensors, and a control system controls an electric cylinder to move the separators, thereby altering the pressure exerted by the separators on the battery cells and regulating the pressure on each cell. This design is complex and costly. Furthermore, due to manufacturing tolerances, surface differences between the battery cells and separators are unavoidable. Consequently, when the separators compress the battery cells, uneven stress can easily occur across the cells, resulting in poor performance.

[0107] In view of this, embodiments of this application propose a battery device, which includes a housing, a battery cell, and a buffer. The housing has a receiving cavity; the battery cell is disposed in the receiving cavity; the buffer is disposed in the receiving cavity, and the buffer includes a buffer body and a pressure balancing part. The buffer body is attached to one side surface of the battery cell, and the buffer body includes a film layer and a buffer medium. The film layer defines a buffer space, the buffer medium is contained in the buffer space, and the pressure balancing part defines the receiving space. The receiving space and the buffer space are in communication. The buffer is constructed such that at least a portion of the buffer medium adaptively shifts between the buffer space and the receiving space according to the deformation of the battery cell.

[0108] In this type of battery device, by attaching a buffer to one side surface of the battery cell, during the expansion of the battery cell, the cell compresses the buffer body, increasing the pressure between them. This compresses the buffer medium within the buffer body, causing it to shift into the containment space, thus preventing excessive pressure increase between the battery cell and the buffer body. Conversely, during the contraction of the battery cell after expansion, the pressure exerted on the buffer body decreases, and the buffer medium in the containment space flows back into the buffer space, preventing excessive pressure decrease. Therefore, the buffer ensures that the pressure on the battery cell remains within a relatively small range, neither too high nor too low. Furthermore, the buffer structure is simple, low-cost, and easy to use. Additionally, due to the fluidity of the buffer medium and the flexibility of the film, a good fit can be maintained between the battery cell surface and the buffer body, resulting in more uniform stress distribution and reducing the risk of stress concentration in the battery cell.

[0109] The following is for reference. Figures 3-8 A battery device 100 according to an embodiment of this application is described.

[0110] See Figures 3 to 8This application proposes a battery device 100, including a housing 10, a battery cell 20, and a buffer 30.

[0111] The housing 10 has a receiving cavity 103; the battery cell 20 is disposed in the receiving cavity 103; the buffer 30 is disposed in the receiving cavity 103, and the buffer 30 includes a buffer body 301 and a pressure balancing part 302. The buffer body 301 is attached to one side surface of the battery cell 20. The buffer body 301 includes a membrane layer 3011 and a buffer medium 3012. The membrane layer 3011 defines a buffer space 3013. The buffer medium 3012 is accommodated in the buffer space 3013 formed by the membrane layer 3011. The pressure balancing part 302 defines a receiving space 3021, and the receiving space 3021 is in communication with the buffer space 3013. The buffer 30 is constructed such that at least part of the buffer medium 3012 adaptively moves between the buffer space 3013 and the receiving space 3021 according to the deformation of the battery cell 20.

[0112] Specifically, the buffer body 301 may be attached to the entire surface of one side of the battery cell 20; or, the buffer body 301 may be attached to the lower middle part of one side surface of the battery cell 20; or, the buffer body 301 may be attached to the part of the battery cell 20 that is prone to expansion; or, the buffer body 301 may be attached to the part of the battery cell 20 that needs to be pressurized to obtain better performance; or, the buffer body 301 may also be partially attached to one side surface of the battery cell 20, while the other part of the buffer body 301 is not attached to one side surface of the battery cell 20.

[0113] The buffer body 301 includes a membrane layer 3011 and a buffer medium 3012. The buffer medium 3012 is contained in the buffer space 3013 formed by the membrane layer 3011. Here, the membrane layer 3011 is flexible and can change with the shape of the contact surface, so as to transmit pressure in a timely manner. At the same time, the buffer medium 3012 is flowable. Therefore, the surface of the battery cell 20 in contact with a buffer body 301 can be guaranteed to be subjected to equal stress everywhere. That is, the buffer 30 can apply uniform stress to the battery cell 20. The problem of stress concentration between the battery cell 20 and the buffer body 301 is not easy to occur. This helps to reduce the risk of excessive local stress on the battery cell 20, improves the performance and service life of the battery cell 20, and thus improves the reliability of the battery device 100.

[0114] In the above embodiments, the buffer medium 3012 at normal ambient temperature can be a liquid, or a gel, fat, polymer solution, solid-liquid mixture, etc., that exhibits flow characteristics. Furthermore, the buffer medium 3012 at normal ambient temperature can also be a gas. Here, normal ambient temperature typically refers to -30°C to 40°C, but the upper and lower limits of this normal ambient temperature may differ depending on the actual operating environment of the battery device 100.

[0115] The pressure balancing section 302 defines a receiving space 3021, which is connected to a buffer space 3013 so that the buffer medium 3012 can be transferred between the receiving space 3021 and the buffer space 3013. The buffer space 3013 and the receiving space 3021 can be directly connected or can be connected to each other through flow channels formed by separate components, for example, through a connecting pipe 303.

[0116] The buffer 30 is constructed such that at least a portion of the buffer medium 3012 adaptively shifts between the buffer space 3013 and the receiving space 3021 according to the deformation of the battery cell 20. For example, during the expansion and volume increase of the battery cell 20, the battery cell 20 compresses the buffer body 301, increasing the pressure between the battery cell 20 and the buffer body 301. The buffer medium 3012 in the buffer body 301 is compressed and shifts to the receiving space 3021, thus preventing an excessive increase in pressure between the battery cell 20 and the buffer body 301, i.e., preventing excessive pressure on the battery cell 20. During the contraction process after expansion, the pressure exerted by the battery cell 20 on the buffer body 301 decreases, and the buffer medium 3012 in the receiving space 3021 automatically flows back to the buffer space 3013, thus preventing an excessive decrease in pressure between the battery cell 20 and the buffer body 301. Therefore, by setting up the buffer, the pressure on the battery cell 20 can be kept within a small range, meaning the pressure on the battery cell 20 will not be too high or too low. The entire process does not require an external drive source, meaning no energy consumption, such as electricity, is required, nor does it require an additional drive source. This makes the entire buffer 30 simple in structure, low in cost, and easy to use.

[0117] In some embodiments, reference may be made to Figure 6 and Figure 8As shown, the pressure balancing part 302 includes a housing 3022 and a sliding member 3023. The housing 3022 has a columnar cavity and is connected to the membrane layer 3011. The sliding member 3023 is disposed in the cavity and contacts and engages with the side wall of the cavity. The sliding member 3023 divides the cavity into a first chamber 3024 and a second chamber 3025 arranged along its length direction F. The accommodating space 3021 includes the second chamber 3025. The sliding member 3023 slides along the length direction F of the cavity under the action of the pressure difference in the first chamber 3024 and the second chamber 3025 to change the volume of the second chamber 3025.

[0118] Specifically, the cavity of the housing 3022 can be cylindrical or prismatic. To ensure the stable sliding of the sliding member 3023, a guide portion can be provided in the cavity to guide the sliding member 3023. No specific limitation is made here. The sliding member 3023 is disposed in the cavity and contacts and engages with the side wall 105 of the cavity. The sliding member 3023 divides the cavity into a first chamber 3024 and a second chamber 3025 arranged along its length direction F. Here, the length direction F can be understood as the axial direction of the cylindrical cavity. The first chamber 3024 and the second chamber 3025 are not connected to each other. The first chamber 3024 contains gas, which can be air, nitrogen, or other gases. No specific limitation is made here, so that the first chamber 3024 can be compressed to reduce its volume and can expand to restore its volume when the pressure decreases.

[0119] When the buffer body 301 is squeezed by the battery cell 20, causing the pressure in the second chamber 3025 to increase, under the pressure difference between the first chamber 3025 and the second chamber 3024, when the sliding member 3023 moves along the length direction F towards one side of the first chamber 3024, the volume of the first chamber 3024 decreases, the gas in the first chamber 3024 is compressed, and the pressure increases until the pressure in the first chamber 3024 and the pressure in the second chamber 3025 reach equilibrium. At the same time, the buffer medium 3012 flows into the second chamber 3025.

[0120] When the pressure exerted by the battery cell 20 on the buffer body 301 decreases, the pressure in the second chamber 3025 decreases, the gas in the first chamber 3024 expands and recovers, causing the sliding member 3023 to move along the length direction F to one side of the second chamber 3025, so that the buffer medium 3012 in the second chamber 3025 flows back to the buffer space 3013.

[0121] In the initial state, the initial state here can refer to the state in which the battery cell 20 has not been deformed, or the state in which the buffer 30 is installed and can be used normally, but is not used. The volume of the second chamber 3025 can be zero or much smaller than the volume of the first chamber 3024, so that the first chamber 3024 has a large compressibility, that is, the pressure balance part 302 has a large pressure balance capability.

[0122] Correspondingly, during the expansion of the battery cell 20, the buffer body 301 is compressed, increasing the pressure in the buffer space 3013. Since the second chamber 3025 is connected to the buffer space 3013, the pressure in the second chamber 3025 also increases. Under the pressure difference between the first chamber 3024 and the second chamber 3025, the sliding member 3023 moves towards the first chamber 3024 to compress the gas in the first chamber 3024. Simultaneously, the volume of the second chamber 3025 increases, and the buffer medium 3012 flows into the buffer space 3013. This prevents the pressure in the buffer space 3013 from increasing excessively. During the contraction of the battery cell 20, the compressive force on the buffer body 301 decreases, thereby reducing the pressure in the buffer space 3013 and the second chamber 3025. Under the pressure difference between the first chamber 3024 and the second chamber 3025, the sliding member 3023 moves to one side of the second chamber 3025 to compress the buffer medium 3012, causing the buffer medium 3012 to flow back into the buffer space 3013, so that the pressure on the battery cell 20 is maintained within a small range.

[0123] In the above embodiments, by providing a pressure balancing part 302 including a housing 3022 and a sliding member 3023, the pressure on the battery cell 20 from the buffer body 301 can be maintained within a small range. Meanwhile, the buffer member 30 in this application does not require an additional driving member, reducing energy consumption, and has a simple structure, is easy to arrange, has a long service life, and low operating costs.

[0124] In some embodiments, reference may be made to Figure 6 and Figure 8 The buffer 30 also includes a connecting pipe 303, which is connected between the membrane layer 3011 and the housing 3022, and communicates with the second chamber 3025 and the buffer space 3013.

[0125] Specifically, the connecting pipe 303 can be a rigid connecting pipe or a flexible connecting pipe. The setting of the connecting pipe 303 allows the housing 3022 to be arranged in a suitable position according to the usage and design requirements, or allows for more freedom in the size design of the housing 3022, which facilitates the efficient use of space; at the same time, it can also reduce the possibility of interference between the housing 3022 and the surrounding parts of the battery cell 20.

[0126] In other embodiments, the pressure balancing part 302 includes an elastic membrane with an elastic coefficient less than that of the membrane layer 3011. The elastic membrane defines a receiving space 3021 and is deformable under the action of the buffer medium 3012 to change the volume of the receiving space 3021.

[0127] Specifically, the elastic membrane is relatively easy to undergo elastic deformation. For example, the elastic membrane can be a polyurethane membrane or a latex membrane, etc. Exemplarily, the elastic membrane and the membrane layer 3011 are integrally formed. Alternatively, the elastic membrane and the membrane layer 3011 are formed separately and then connected to each other by heat fusion; or, the elastic membrane and the membrane layer 3011 are also connected to each other by connecting tube 303.

[0128] During the expansion of the battery cell 20, the buffer body 301 is compressed, and the compressive force on the buffer medium 3012 increases. Since the elastic coefficient of the elastic membrane is less than that of the membrane layer 3011, the elastic membrane stretches under the compression of the buffer medium 3012, while the membrane layer 3011 does not. This increases the volume of the accommodating space 3021 to accommodate the buffer medium 3012, thus preventing an excessive increase in pressure in the buffer space 3013. During the contraction of the battery cell 20 after expansion, the compressive force on the buffer body 301 decreases. Under the rebound force of the elastic membrane, the buffer medium 3012 in the accommodating space 3021 is squeezed back into the buffer space 3013, thus preventing an excessive decrease in pressure in the buffer space 3013. In summary, the elastic membrane allows the pressure between the buffer body 301 and the battery cell 20 to be maintained within a relatively small range.

[0129] In the above embodiments, the pressure balancing section 302 includes an elastic membrane. Utilizing the stretchable nature of the elastic membrane, the volume of the accommodating space 3021 can change with the pressure exerted by the battery cell 20 on the buffer body 301, reducing the possibility of excessive or insufficient pressure on the battery cell 20 and ensuring optimal performance. Furthermore, by rationally positioning the elastic membrane, the buffer medium 3012 can enter a suitable spatial location after the buffer body 301 is compressed, resulting in a simpler structure and better integration of the pressure balancing section 302.

[0130] In some embodiments, the elastic membrane and the membrane layer 3011 are integrally formed.

[0131] In the above technical solution, since the elastic membrane and membrane layer 3011 are integrally formed, there are no seams between the elastic membrane and membrane layer 3011, and the integrity of the elastic membrane and membrane layer 3011 is better, which helps to make the overall airtightness of the buffer 30 better and less prone to cracks and damage.

[0132] In some embodiments, the initial pressure range of the buffer space 3013 is 0.1 MPa to 20 MPa.

[0133] Here, the initial pressure of the buffer space 3013 refers to the pressure of the buffer space 3013 in its initial state. The initial state can refer to the state where the battery cell 20 has not deformed, or the state where the buffer component 30 is installed and ready for normal use, but not yet in use. For example, the initial pressure of the buffer space 3013 can be adjusted to a suitable value by controlling the pressure of the buffer medium 3012 filled into the buffer space 3013.

[0134] For example, since the pressures in the first chamber 3024 and the second chamber 3025 are equal when the final equilibrium is reached, and the pressures in the second chamber 3025 and the buffer space 3013 are equal, the initial pressure of the buffer space 3013 can be adjusted to a suitable value by changing the initial pressure of the first chamber 3024. For example, the elastic coefficient of the elastic part can be changed so that the elastic part does not undergo significant deformation when the initial pressure of the buffer space 3013 reaches a suitable value.

[0135] For example, the initial pressure of the buffer space 3013 can be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, or any value between any two of these values. It should be noted that different types of battery cells 20 require different operating pressures. In practice, a suitable initial pressure can be selected based on the type and design requirements of the battery cell 20, ensuring that the battery cell 20 operates in a suitable working pressure environment under the compression of the buffer body 301.

[0136] The initial pressure of the buffer space 3013 can be one atmosphere. When the buffer body 301 is compressed, the pressure of the buffer space 3013 increases. The initial pressure of the buffer space 3013 can be greater than one atmosphere. On the one hand, this allows the buffer component 30 to maintain a certain shape and be stably arranged in the housing 10, preventing it from shifting. On the other hand, it can limit the movement of the battery cell 20, reducing the possibility of shaking during use. Furthermore, pressure changes may affect the internal pore structure of the electrode material inside the battery cell 20 and its contact area with the electrolyte. Appropriate external pressure helps improve the contact between the electrode material and the electrolyte, reducing interfacial resistance and thus improving battery performance. Therefore, by adjusting the pressure of the buffer space 3013, the battery cell 20 can be made to operate within a suitable pressure range to achieve better performance.

[0137] In some embodiments, the initial pressure range of the buffer space 3013 can be 0.1 MPa to 3.5 MPa.

[0138] For example, the initial pressure of the buffer space 3013 can be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1 MPa, 1.1 MPa, 1.2 MPa, 1.3 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa, 1.7 MPa, 1.8 MPa, 1.9 MPa, 2 MPa, 2.1 MPa, 2.2 MPa, 2.3 MPa, 2.4 MPa, 2.5 MPa, 2.6 MPa, 2.7 MPa, 2.8 MPa, 2.9 MPa, 3 MPa, 3.1 MPa, 3.2 MPa, 3.3 MPa, 3.4 MPa, 3.5 MPa, or any value between any two of these values.

[0139] It should be noted that different types of battery cells 20 require different working environment pressures. In practice, an appropriate initial pressure can be selected according to the type and design of the battery cell 20, so that the battery cell 20 can work in a suitable working pressure environment under the squeezing action of the buffer body 301.

[0140] The initial pressure of the buffer space 3013 can be one atmosphere. When the buffer body 301 is compressed, the pressure of the buffer space 3013 increases. The initial pressure of the buffer space 3013 can be greater than one atmosphere. On the one hand, this allows the buffer component 30 to maintain a certain shape and be stably arranged in the housing 10, preventing it from shifting. On the other hand, it can limit the movement of the battery cell 20, reducing the possibility of shaking during use. Furthermore, pressure changes may affect the internal pore structure of the electrode material inside the battery cell 20 and its contact area with the electrolyte. Appropriate external pressure helps improve the contact between the electrode material and the electrolyte, reducing interfacial resistance and thus improving battery performance. Therefore, by adjusting the pressure of the buffer space 3013, the battery cell 20 can be kept within a suitable pressure range to achieve better performance.

[0141] In some embodiments, reference may be made to Figure 8 Membrane 3011 includes reinforcing membrane 3014, which includes a prestressed membrane. Reinforcing membrane 3014 includes a composite material membrane. Reinforcing membrane 3014 includes both a prestressed membrane and a composite material membrane.

[0142] For example, the reinforcing membrane layer 3014 can be a prestressed membrane layer. Here, a prestressed membrane layer refers to a prestressed membrane layer obtained by applying prestress to the material during processing using processes such as heating and stretching. The prestressed membrane layer has high elastic modulus and good toughness. For example, the prestressed membrane layer can be a multi-axial prestressed membrane layer. For instance, the prestressed membrane layer includes multiple sub-prestressed membrane layers, each with a different prestress direction, so that the prestressed membrane layer has large tensile strength in all directions.

[0143] For example, the composite membrane can be a composite membrane reinforced with aramid fiber, carbon fiber or other types of fiber, which has high elastic modulus and good toughness and is not easily elastically deformed.

[0144] It should be noted that the reinforcing film 3014 is flexible and can fit well with the surface of the battery cell 20. It is also not prone to elastic deformation, so that the buffer medium 3012 can be squeezed into the receiving space 3021 when the pressure of the buffer space 3013 increases. Furthermore, when the buffer space 3013 is under initial pressure, the reinforcing film 3014 will not undergo uncontrollable large elastic deformation and can maintain the required shape and volume. This is beneficial to improving the performance consistency of multiple battery devices 100 and reducing the possibility of the buffer 30 affecting other structures in the battery device 100.

[0145] In some embodiments, reference may be made to Figure 8The battery device 100 also includes a heat-resistant layer 3015, which is stacked with a film layer 3011. The heat-resistant layer 3015 is located on the side of the film layer 3011 facing away from the buffer medium 3012 and is attached to one side surface of the battery cell 20.

[0146] Specifically, the heat-resistant layer 3015 can be silicone or rubber, etc. For example, the heat-resistant layer 3015 and the reinforcing film layer 3014 are stacked, with the heat-resistant layer 3015 located on the side of the reinforcing film layer 3014 facing away from the buffer medium 3012 and attached to one side surface of the battery cell 20. In other words, the heat-resistant layer 3015 is located on the outer layer and is in direct contact with the battery cell 20 and the surrounding environment, which may generate high temperatures. Because the heat-resistant layer 3015 has good heat resistance, it is not prone to melting and breakage at higher temperatures, such as below 200 degrees Celsius.

[0147] Here, the heat-resistant layer 3015 allows the membrane layer 3011 to have good environmental adaptability. For example, when the ambient temperature is too high or too low, or when the temperature of the battery cell 20 is high, the membrane layer 3011 of the buffer body 301 is not easily damaged, which would cause the buffer medium 3012 to leak. This helps to reduce the safety risks of using the buffer component 30.

[0148] For example, membrane layer 3011 may include a reinforcing membrane layer 3014 and a heat-resistant layer 3015. The reinforcing membrane layer 3014 may be a thermoplastic polyurethane layer reinforced with ultra-high molecular weight polyethylene fibers, with the ultra-high molecular weight polyethylene fibers embedded in the thermoplastic polyurethane layer in a woven or mesh form. The heat-resistant layer 3015 may be a silicone membrane layer. The thermoplastic polyurethane layer possesses good elasticity, abrasion resistance, and chemical corrosion resistance. Its flexible nature makes it suitable for large-area contact with the battery cell 20, serving as an inner layer material to provide a soft contact surface and good sealing. Silicone has good heat resistance and flexibility, capable of withstanding extreme temperature changes. Used as an outer protective material, it provides additional chemical corrosion resistance and temperature resistance, reducing the possibility of membrane layer 3011 breaking due to heat and reducing the possibility of the overall structure being affected by the external environment.

[0149] In some embodiments, the buffer medium 3012 is configured to undergo a phase change and transform into a liquid state when the battery cell 20 is heated to a set temperature. That is, the buffer medium 3012 can exchange heat with the battery cell 20.

[0150] When the temperature of the battery cell 20 rises, the buffer medium 3012 undergoes a phase change to become liquid, which efficiently absorbs the heat of the battery cell 20 and reduces the rate of temperature rise of the battery cell 20. When the temperature of the battery cell 20 decreases, such as when the ambient temperature decreases, the buffer medium 3012 undergoes a phase change to become gel or solid-liquid mixture, which releases heat to heat the battery cell 20, so that the temperature of the battery cell 20 does not drop too low. That is, the buffer 30 can also be used for the thermal management of the battery cell 20. The whole process does not require additional energy consumption, which helps to reduce the energy consumption of thermal management of the battery cell 20.

[0151] For example, before the battery cell 20 reaches the set temperature, the buffer medium 3012 can be a gel-like substance, or the buffer medium 3012 can be a solid-liquid mixture with good fluidity and relatively uniform dispersion. During the phase change process, the solid in the solid-liquid mixture will undergo a solid-liquid phase change; or the buffer medium 3012 can also be a polymer solution with good fluidity, fat, etc.

[0152] It should be noted that the set temperature here can be the upper limit of the operating temperature of the battery cell 20, or the extreme temperature of the surrounding environment of the battery cell 20 during normal use of the battery device 100. For example, in some regions, the ambient temperature in summer exceeds 40°C, which is higher than the upper limit of the operating temperature of the battery cell 20. In practice, this set temperature can be reasonably designed according to the type of battery cell 20, the actual use environment of the battery cell 20, and other design requirements, so that the buffer medium 3012 can undergo a phase change to liquid at a suitable temperature to efficiently remove the heat generated by the battery cell 20 without changing or significantly increasing the temperature of the buffer medium 3012 itself, thereby reducing the possibility of overheating of the battery cell 20 and ensuring better performance of the battery cell 20. On the other hand, the phase change of the buffer medium 3012 to liquid can generate thermal convection, increasing the heat exchange rate between the buffer medium 3012 and the battery cell 20.

[0153] In some embodiments, the temperature is set to be greater than or equal to the upper limit of the operating temperature of the battery cell 20.

[0154] Different types of batteries have different operating temperature ranges. For lithium-ion batteries, the suitable operating temperature range is usually 0°C to 44°C. When the battery cell 20 operates within its operating range, it helps to extend battery life and improve battery efficiency. For example, the set temperature can be 44°C. When the temperature of the battery cell 20 rises to 44°C, the buffer medium 3012 begins to undergo a phase change and transforms into a liquid state.

[0155] The temperature is set to be greater than or equal to the upper limit of the operating temperature of the battery cell 20. In this way, once the temperature of the battery cell 20 reaches or exceeds the upper limit of the operating temperature of the battery cell 20, the buffer medium 3012 will undergo a phase change and absorb heat to reduce the heating rate of the battery cell 20, reduce the risk of overheating of the battery cell 20, and reduce the risk of accelerated aging and thermal runaway of the battery cell 20.

[0156] In some embodiments, the temperature is set to 40°C to 60°C.

[0157] For example, the set temperature can be 40℃, 41℃, 42℃, 43℃, 44℃, 45℃, 46℃, 47℃, 48℃, 49℃, 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃, 60℃, or any value between any two of these. In practice, the set temperature value can be reasonably set according to the type of battery cell 20, the ambient temperature of the battery cell 20, and design requirements.

[0158] The set temperature cannot be too high. For example, if the buffer medium 3012 only undergoes a phase change at a high temperature, such as when the battery cell 20 has already started to overheat, then the purpose of effective thermal management of the battery cell 20 cannot be achieved. Conversely, the set temperature cannot be too low. For example, if the battery cell 20 is still operating within its own operating temperature range, and the ambient temperature is too high, the buffer medium 3012 will begin to absorb heat and undergo a phase change. By the time the battery cell 20's own temperature becomes too high, the buffer medium 3012 will have completely changed phase to liquid. At this point, the buffer medium 3012 will also fail to achieve efficient heat absorption. When the set temperature is within this range, the buffer medium 3012 can efficiently absorb a large amount of heat, preventing the battery cell 20 from overheating, and allowing the buffer component 30 to be used in most environments.

[0159] In some embodiments, the buffer medium 3012 is configured such that it undergoes a phase transition from a gel state to a liquid state when the battery cell 20 is heated to a set temperature. That is, below the set temperature, the buffer medium is in a gel state. This results in better uniformity and stability of the buffer medium below the set temperature.

[0160] For example, buffer medium 3012 comprises a mixture of lauric acid and propylene glycol.

[0161] It should be noted that lauric acid undergoes a phase transition at 44℃, with a latent heat value of 178–210 KJ / kg, exhibiting a suitable phase transition temperature and a relatively large latent heat value. The mixture obtained by mixing lauric acid and propylene glycol does not solidify at -30℃, thus giving buffer medium 3012 better environmental adaptability.

[0162] In some embodiments, the battery device 100 includes a plurality of battery cell assemblies, each battery cell assembly including a plurality of battery cells 20; in at least one buffer 30, the number of buffer bodies 301 is plurality of and at least two buffer bodies 301 are connected to the same pressure balancing part 302, and the plurality of battery cells 20 in the at least one battery cell assembly are fitted together with the plurality of buffer bodies 301 of a buffer 30.

[0163] In other words, a single battery cell assembly can correspond to only one buffer 30; or, a single battery cell assembly can correspond to multiple buffers 30; or, multiple battery cell assemblies can be equipped with one buffer 30. For multiple buffers 30, the number of their buffer bodies 301 can be the same or different. In this way, the buffers 30 can adapt to different usage scenarios, and the arrangement of the buffers 30 will be more flexible.

[0164] In some embodiments, the battery device 100 includes a plurality of battery cells 20. In at least one buffer member 30, the number of buffer bodies 301 is plurality of, and at least two buffer bodies 301 are connected to the same pressure balancing part 302. The plurality of battery cells 20 are fitted with the plurality of buffer bodies 301 of a buffer member 30. A battery cell 20 may be fitted with only one buffer body 301; or, a battery cell 20 may be fitted with multiple buffer bodies 301; or, a buffer body 301 may be fitted with multiple battery cells 20. A battery device 100 may have multiple buffer members 30. For the multiple buffer members 30 in a battery device 100, the number of buffer bodies 301 may be the same or different, or a battery device 100 may have only one buffer member 30. A battery device 100 may also have only one buffer member 30.

[0165] For a single buffer element 30, only one pressure balancing part 302 can be provided, with multiple buffer bodies 301 in the buffer element 30 all connected to one pressure balancing part 302. Alternatively, for a single buffer element 30, multiple pressure balancing parts 302 can be provided, but the number of pressure balancing parts 302 is less than the number of buffer bodies 301, with at least two buffer bodies 301 connected to one pressure balancing part 302. Alternatively, for a single buffer element 30, one buffer body 301 can also be connected to multiple pressure balancing parts 302. In this way, the buffer element 30 can adapt to different usage scenarios, and its arrangement becomes more flexible.

[0166] In some embodiments, the battery device 100 includes a plurality of battery cells 20, and the buffer 30 includes a plurality of buffer bodies 301 and a plurality of pressure balancing parts 302. The plurality of buffer bodies 301 and the plurality of pressure balancing parts 302 are connected in a one-to-one correspondence, and a battery cell 20 is fitted with at least one buffer body 301.

[0167] In other words, one buffer body 301 is connected to only one pressure balancing part 302. One buffer body 301 can be attached to only one battery cell 20, or it can be attached to multiple battery cells 20. This allows the buffer 30 to adapt to different usage scenarios, and its arrangement is more flexible.

[0168] In some embodiments, reference may be made to Figure 3 and Figure 5 The battery device 100 includes a plurality of battery cell assemblies arranged along a first direction F1, each battery cell assembly including a plurality of battery cells 20 arranged along a second direction F2, the first direction F1 and the second direction F2 intersect; the battery cells 20 are attached to the buffer body 301 at least on both sides along the second direction F2.

[0169] For example, the first direction F1 and the second direction F2 can be perpendicular to each other. In other embodiments, the included angle between the first direction F1 and the second direction F2 can also be an acute angle.

[0170] Typically, the two sides of the battery cell 20 along the second direction F2 are the sides with the largest area of ​​the battery cell 20. Therefore, the battery cell 20 is in contact with the buffer body 301 at least on the two sides along the second direction F2. The contact area between the battery cell and the buffer body is large, and the heat exchange effect between the buffer body and the battery cell is good.

[0171] In some embodiments, reference may be made to Figure 2 and Figure 3 The housing 10 includes a bottom wall 104 and a peripheral wall 105 connected to the circumferential edge of the bottom wall 104; a buffer body 301 is provided between two adjacent battery cells 20, and a pressure balancing part 302 is located between the peripheral wall 105 and the battery cell 20.

[0172] In some embodiments, the housing 10 includes a bottom wall 104 and a peripheral wall 105 connected to the circumferential edge of the bottom wall 104; a buffer body 301 is provided between the battery cell 20 and the beam inside the housing 10; and a pressure balancing part 302 is located between the peripheral wall 105 and the battery cell 20.

[0173] In some embodiments, the housing 10 includes a bottom wall 104 and a peripheral wall 105 connected to the circumferential edge of the bottom wall 104; a buffer body 301 is provided between the battery cell 20 and the peripheral wall of the housing 10; and a pressure balancing part 302 is located between the peripheral wall 105 and the battery cell 20.

[0174] It should be noted that, in order to reduce the risk of damage to the battery cells 20 due to the direct transmission of collision deformation from the housing 10 to the battery cells 20 during a side impact, a side impact space is typically reserved between the peripheral wall 105 of the housing 10 and the battery cells 20. The pressure balancing unit 302 can be arranged between the peripheral wall 105 and the battery cells 20, i.e., within the reserved side impact space, thus eliminating the need for additional space to accommodate the pressure balancing unit 302 and improving the space utilization efficiency of the battery device 100.

[0175] Specifically, you can refer to Figure 2 The housing 10 may include a bottom wall 104, a peripheral wall 105 connected to the circumferential edge of the bottom wall 104, and a top wall 106 disposed opposite to the bottom wall 104. The bottom wall 104, peripheral wall 105, and top wall 106 together define the receiving space 3021. The housing 10 may also be provided with beams, which can divide the receiving cavity 103 into multiple sub-chambers. A buffer body 301 may be provided between two adjacent battery cells 20, and a buffer body 301 may also be provided between the battery cell 20 and the peripheral wall 105 or the beams inside the housing 10.

[0176] For example, one can refer to Figure 3 Multiple battery cells 20 are arranged sequentially along their thickness direction, and each battery cell 20 may have a buffer member 30 on both sides along its thickness direction. Multiple battery cells 30 are arranged sequentially along their width direction, and one side surface of the multiple battery cells 30 arranged sequentially along their width direction may be attached to the same buffer body 301.

[0177] In some embodiments, the battery device 100 further includes a heat exchanger, and the battery cell 20 includes an intersecting first wall and a second wall. The first wall is fitted with the buffer 30, and the heat exchanger is fitted with the second wall and is used to exchange heat with the battery cell 20.

[0178] It should be noted that the heat exchanger here may be used only to heat the battery cell 20; or, the heat exchanger may be used only to remove the heat from the battery cell 20; or, the heat exchanger may be used to both heat the battery cell 20 and remove the heat from the battery cell 20.

[0179] For example, the heat exchanger can be a heat exchange plate with a heat exchange medium flowing inside. The heat exchanger can be used to assist in heating or cooling the battery cell 20 to cope with extreme conditions, such as usage scenarios with extreme temperature changes, making the battery device 100 more capable of handling extreme conditions.

[0180] The buffer 30 is attached to the first wall of the battery cell 20, and the heat exchanger is attached to the second wall of the battery cell 20. In other words, the heat exchanger and the buffer 30 are attached to different walls of the battery cell 20, so that the heat exchanger can directly exchange heat with the battery cell 20 and will not exchange heat with the buffer 30. This reduces the possibility that the buffer 30 will absorb the energy of the heat exchanger, which is conducive to the efficient utilization of the energy of the heat exchanger, so that the heat exchanger can quickly cool and quickly heat the battery cell 20.

[0181] This application provides a buffer for a battery device 100, the battery device 100 including a battery cell 20, the buffer 30 including a buffer body 301 and a pressure balancing part 302, the buffer body 301 for adhering to one side surface of the battery cell 20, the buffer body 301 including a film layer 3011 and a buffer medium 3012, the film layer 3011 defining a buffer space 3013, the buffer medium 3012 being accommodated in the buffer space 3013; the pressure balancing part 302 defining a accommodating space 3021, the accommodating space 3021 communicating with the buffer space 3013; the buffer 30 is configured such that at least a portion of the buffer medium 3012 adaptively shifts between the buffer space 3013 and the accommodating space 3021 according to the deformation of the battery cell 20.

[0182] In the above technical solution, by setting the buffer 30 to fit against one side surface of the battery cell 20, during the expansion and volume increase of the battery cell 20, the battery cell 20 will compress the buffer body 301, increasing the pressure between the battery cell 20 and the buffer body 301. The buffer medium in the buffer body 301 is compressed and will transfer to the receiving space, thus preventing excessive pressure increase between the battery cell 20 and the buffer body 301, i.e., the pressure on the battery cell 20 will not be too high. During the contraction process after expansion, the pressure exerted by the battery cell 20 on the buffer body 301 decreases, and the buffer medium in the receiving space 3021 will flow back into the buffer space 3013, thus preventing excessive pressure decrease between the battery cell 20 and the buffer body 301. Therefore, by setting the buffer 30, the pressure on the battery cell 20 can always be kept within a small range, i.e., the pressure on the battery cell 20 will not be too high or too low. Furthermore, the entire buffer 30 of this application has a simple structure, low cost, and is easy to use. In addition, due to the fluidity of the buffer medium and the flexibility of the membrane layer 3011, the surface of the battery cell 20 and the buffer body 301 can maintain good adhesion, and the battery cell 20 is subjected to more uniform force, reducing the risk of stress concentration in the battery cell 20.

[0183] In some embodiments, the pressure balancing part 302 includes a housing 3022 and a slider 3023. The housing 3022 has a columnar cavity and is connected to the membrane layer 3011. The slider 3023 is disposed in the cavity and contacts and engages with the sidewall 105 of the cavity. The slider 3023 divides the cavity into a first chamber 3024 and a second chamber 3025 arranged along its length direction F. The accommodating space 3021 includes the second chamber 3025. The slider 3023 slides along the length direction F of the cavity under the action of the pressure difference in the first chamber 3024 and the second chamber 3025 to change the volume of the second chamber 3025.

[0184] In the above embodiments, by providing a pressure balancing part 302 including a housing 3022 and a sliding member 3023, the pressure on the battery cell 20 from the buffer body 301 can be maintained within a small range. Meanwhile, the buffer member 30 in this application does not require an additional driving member, reducing energy consumption, and has a simple structure, is easy to arrange, has a long service life, and low operating costs.

[0185] In some embodiments, the pressure balancing part 302 includes an elastic membrane with an elastic coefficient less than that of the membrane layer 3011. The elastic membrane defines a receiving space 3021 and is deformable under the action of the buffer medium 3012 to change the volume of the receiving space 3021.

[0186] In the above embodiments, the pressure balancing section 302 includes an elastic membrane. Utilizing the stretchable nature of the elastic membrane, the volume of the accommodating space 3021 can change with the pressure exerted by the battery cell 20 on the buffer body 301, reducing the possibility of excessive or insufficient pressure on the battery cell 20 and ensuring optimal performance. Furthermore, by rationally positioning the elastic membrane, the buffer medium 3012 can enter a suitable spatial location after the buffer body 301 is compressed, resulting in a simpler structure and better integration of the pressure balancing section 302.

[0187] This application provides an electrical device, including the battery device 100 described above, which is used to store or provide electrical energy.

[0188] Other configurations and operations of the battery device 100 and the power consumption device 400 according to the embodiments of this application are known to those skilled in the art and will not be described in detail here.

[0189] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0190] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery device, characterized in that, include: The box-shaped enclosure has a receiving cavity; A single battery cell is disposed in the receiving cavity; A buffer element is disposed in the receiving cavity. The buffer element includes a buffer body and a pressure balancing part. The buffer body is attached to one side surface of the battery cell. The buffer body includes a membrane layer and a buffer medium. The membrane layer defines a buffer space. The buffer medium is contained in the buffer space. The pressure balancing part defines a receiving space. The receiving space is in communication with the buffer space. The buffer is configured such that at least a portion of the buffer medium adaptively shifts between the buffer space and the containment space according to the deformation of the battery cell.

2. The battery device as claimed in claim 1, characterized in that, The pressure balancing unit includes: A housing having a columnar cavity, the housing being connected to the membrane layer; A sliding member is disposed in the cavity and contacts and engages with the sidewall of the cavity, the sliding member dividing the cavity into a first chamber and a second chamber arranged along its length; The accommodating space includes the second chamber, and the sliding member slides along the length of the cavity under the pressure difference between the first chamber and the second chamber to change the volume of the second chamber.

3. The battery device as claimed in claim 2, characterized in that, The buffer also includes a connecting pipe that connects the membrane layer and the housing, and communicates with the second chamber and the buffer space.

4. The battery device as claimed in claim 1, characterized in that, The pressure balancing section includes an elastic membrane with an elastic coefficient less than that of the membrane layer. The elastic membrane defines the accommodating space and is deformable under the action of the buffer medium to change the volume of the accommodating space.

5. The battery device as claimed in claim 4, characterized in that, The elastic membrane is integrally formed with the membrane layer.

6. The battery device according to any one of claims 1-5, characterized in that, The initial pressure range of the buffer space is 0.1 MPa to 20 MPa.

7. The battery device as claimed in claim 6, characterized in that, The initial pressure range of the buffer space is 0.1 MPa to 3.5 MPa.

8. The battery device according to any one of claims 1-5, characterized in that, The membrane layer includes a reinforcing membrane layer, which includes a prestressed membrane layer and / or a composite material membrane layer.

9. The battery device as described in any one of claims 1-5, characterized in that, The buffer body also includes a heat-resistant layer, which is stacked with the film layer. The heat-resistant layer is located on the side of the film layer facing away from the buffer medium and is attached to one side surface of the battery cell.

10. The battery device according to any one of claims 1-5, characterized in that, The buffer medium is constructed such that when the battery cell reaches a set temperature, it undergoes a phase change and transforms into a liquid state.

11. The battery device as claimed in claim 10, characterized in that, The set temperature is greater than or equal to the upper limit of the operating temperature of the battery cell.

12. The battery device as claimed in claim 10, characterized in that, The set temperature is 40℃~60℃.

13. The battery device as claimed in claim 10, characterized in that, The buffer medium is constructed such that when the battery cell reaches a set temperature, a phase transition occurs, changing it from a gel state to a liquid state.

14. The battery device according to any one of claims 1-5, characterized in that, The battery device includes a plurality of battery cells. In at least one of the buffer components, the number of buffer bodies is multiple and at least two of the buffer bodies are connected to the same pressure balancing part. The plurality of battery cells are fitted together with the plurality of buffer bodies of one buffer component.

15. The battery device according to any one of claims 1-5, characterized in that, The battery device includes a plurality of battery cells, and the buffer includes a plurality of buffer bodies and a plurality of pressure balancing parts. The plurality of buffer bodies and the plurality of pressure balancing parts are connected in a one-to-one correspondence, and each battery cell is fitted with at least one buffer body.

16. The battery device according to any one of claims 1-5, characterized in that, The battery device includes a plurality of battery cell assemblies arranged along a first direction, and each battery cell assembly includes a plurality of battery cells arranged along a second direction, wherein the first direction and the second direction intersect; the battery cells are in contact with the buffer body at least on two sides along the second direction.

17. The battery device as claimed in claim 1, characterized in that, The enclosure includes a bottom wall and a peripheral wall connected to the circumferential edge of the bottom wall; The buffer body is provided between two adjacent battery cells, and / or the buffer body is provided between the battery cell and the peripheral wall, and / or the buffer body is provided between the battery cell and the beam inside the box; The pressure balancing section is located between the peripheral wall and the battery cell.

18. The battery device as claimed in claim 1, characterized in that, It also includes a heat exchanger, wherein the battery cell includes an intersecting first wall and a second wall, the first wall is fitted to the buffer body, and the heat exchanger is fitted to the second wall and is used to exchange heat with the battery cell.

19. An electrical appliance, characterized in that, Includes a battery device as described in any one of claims 1-18, the battery device being used to store or provide electrical energy.

20. A buffer element, characterized in that, For use in a battery device, the battery device comprising a single battery cell, the buffer comprising: A buffer body is used to adhere to one side surface of the battery cell. The buffer body includes a film layer and a buffer medium. The film layer defines a buffer space, and the buffer medium is accommodated in the buffer space. A pressure balancing section defines a receiving space, which is connected to the buffer space; The buffer is configured such that at least a portion of the buffer medium adaptively shifts between the buffer space and the containment space according to the deformation of the battery cell.

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