Battery module, battery pack, and electric device

Abstract

This disclosure provides a battery module, including: a plurality of battery cells; and a module housing housing the plurality of battery cells. The module housing has a plurality of cavities filled with a fluid medium, and the pressure within each cavity can vary independently. The fluid medium in each cavity immerses a portion of the battery cells, such that at least a portion of the surfaces of the battery cells bears a desired given pressure. By dispersing the plurality of battery cells within the battery module into multiple cavities, and allowing the pressure of the fluid medium in each cavity to vary independently, this disclosure improves the accuracy of pressure monitoring and control around the battery cells, as well as the speed of response.

Description

Technical Field

[0001] This disclosure relates to the field of batteries, specifically to a battery module, a battery pack, and an electrical device. Background Technology

[0002] Liquid batteries, semi-solid batteries, and all-solid batteries represent different technological approaches in the current power battery field. Liquid batteries are mature and low-cost, and have been widely used in electric vehicles. Semi-solid batteries, as a transitional form between liquid and all-solid batteries, combine the characteristics of both liquid and solid electrolytes, improving energy density while maintaining a certain degree of process compatibility. All-solid batteries, due to their non-flammable electrolyte and high energy density, are considered an important development direction for next-generation automotive power.

[0003] Regardless of the battery type, a single battery cell is insufficient to meet the power and range requirements of large loads. Therefore, battery cells must be connected in series and parallel to form a battery system. All-solid-state batteries require a preload of MPa under normal operating conditions to ensure interface contact, while liquid and semi-solid-state batteries also face design requirements regarding pressure balance. Effectively assembling battery cells into groups and designing safety features is crucial for the industrial application of battery systems. Summary of the Invention

[0004] According to a first aspect of this disclosure, a battery module is provided, comprising: a plurality of battery cells; and a module housing for accommodating the plurality of battery cells, the module housing having a plurality of cavities filled with a fluid medium, the pressure in each cavity being independently variable; wherein the fluid medium in each cavity immerses a portion of the plurality of battery cells such that at least a portion of a plurality of surfaces of the battery cells bears a desired given pressure.

[0005] According to some embodiments of this disclosure, the sidewalls of the plurality of cavities include at least one of the battery cell surface or separator.

[0006] According to some embodiments of this disclosure, the plurality of battery cells are arranged inside the module housing, dividing the interior of the module housing into the plurality of cavities.

[0007] According to some embodiments of this disclosure, the surfaces of the plurality of battery cells are sealed to the inner surface of the module housing, so that the pressure in each of the plurality of cavities can vary independently.

[0008] According to some embodiments of this disclosure, the battery cell includes opposing first and second surfaces, the first and second surfaces being respectively immersed in the fluid medium of two cavities, and the other surfaces of the battery cell, other than the first and second surfaces, are not immersed in the fluid medium of the two cavities.

[0009] According to some embodiments of this disclosure, the pressure from the fluid medium on the first and second surfaces is perpendicular to the electrode plates inside the battery cell.

[0010] According to some embodiments of this disclosure, the module housing includes a top wall and a bottom wall. The top wall is provided with a plurality of first grooves, and the bottom wall is provided with a plurality of second grooves that are disposed opposite to the plurality of first grooves. The battery cell includes a first sealing edge and a second sealing edge, which are respectively embedded in the oppositely disposed first groove and second groove.

[0011] According to some embodiments of this disclosure, the first edge sealing and the second edge sealing are embedded in the oppositely arranged first groove and second groove by their respective clamping members, wherein the clamping member includes a clamping space for accommodating the first edge sealing or the second edge sealing and a sidewall forming the clamping space, and the sidewall of the clamping member abuts against the clamped first edge sealing or the second edge sealing to fix the clamped first edge sealing or the second edge sealing.

[0012] According to some embodiments of this disclosure, when the clamping space accommodates the first or second sealing edge, the sidewall of the clamping member elastically abuts against the clamped first or second sealing edge.

[0013] According to some embodiments of this disclosure, the clamping member is sealed to the embedded first or second groove and sealed to the clamped first or second sealing edge, so that the pressure in each of the plurality of cavities can change independently.

[0014] According to some embodiments of this disclosure, the battery cell includes opposing first and second surfaces, and the pressure applied by the fluid medium to the first surface is the same as the pressure applied by the fluid medium to the second surface.

[0015] According to some embodiments of this disclosure, the module housing is provided with a plurality of mounting holes that are respectively connected to the plurality of cavities, and each of the plurality of mounting holes is provided with a fluid control valve, which is used to control the fluid medium to flow out of or into the connected cavity.

[0016] According to some embodiments of this disclosure, the module housing includes a housing wall, and the tabs pass through the housing wall to be positioned outside the fluid medium.

[0017] According to some embodiments of this disclosure, a heat insulation structure is provided between two adjacent battery cells in the plurality of battery cells.

[0018] According to some embodiments of this disclosure, the fluid medium is a liquid.

[0019] According to some embodiments of this disclosure, the fluid medium includes at least one of silicone oil, mineral oil, hydrocarbon synthetic oil, ester synthetic oil, and fluorinated fluids.

[0020] According to some embodiments of this disclosure, the fluid medium includes additives capable of neutralizing harmful substances generated by the battery cell.

[0021] According to some embodiments of this disclosure, the additive may include, for example, at least one of the basic inorganic compounds selected from diisooctyl monoethanolamine, zinc isooctanoate, amino-modified perfluoropolyether, chloride, sulfate, 1-butyl-3-methylimidazolium hexafluorophosphate, and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt.

[0022] According to some embodiments of this disclosure, the battery cell includes a solid electrolyte.

[0023] According to some embodiments of this disclosure, the electrolyte of the battery cell is entirely a solid electrolyte.

[0024] According to some embodiments of this disclosure, the given pressure is higher than atmospheric pressure.

[0025] According to a second aspect of this disclosure, a battery pack is provided, comprising: the battery module described in the first aspect of this disclosure.

[0026] According to some embodiments of this disclosure, the battery pack further includes a battery housing that accommodates the battery module, wherein the battery housing is filled with a fluid medium, and the battery module is at least partially immersed in the fluid medium in the battery housing; the fluid medium in the battery housing may have the same or different composition as the fluid medium in the module housing.

[0027] According to a third aspect of this disclosure, an electrical device is provided, including a battery pack according to a second aspect of this disclosure, the battery pack being used to provide electrical energy.

[0028] This disclosure improves the accuracy of pressure monitoring and control around the battery cells and the speed of response by dispersing and immersing multiple battery cells within a battery module in multiple cavities, and by allowing the pressure of the fluid medium in each cavity to change independently. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a perspective view of a battery module provided in some embodiments of this disclosure.

[0031] Figure 2 This is a plan view of a battery module provided in some embodiments of this disclosure.

[0032] Figure 3 This is a plan view of a battery module provided in some embodiments of this disclosure.

[0033] Figure 4 This is a plan view of a battery module provided in some embodiments of this disclosure.

[0034] Figure 5 for Figure 4 An enlarged view of region A of the battery module.

[0035] Figure 6 for Figure 5 Enlarged view of the clamping component.

[0036] Figure 7 This is a schematic diagram of a battery pack provided in some embodiments of this disclosure. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the described embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0038] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0039] Unless otherwise defined, the features such as "parallel," "perpendicular," and "identical" used in the embodiments of this invention include strictly defined cases of "parallel," "perpendicular," and "identical," as well as cases involving a certain margin of error, such as "approximately parallel," "approximately perpendicular," and "approximately identical." For example, the aforementioned "approximately" may indicate that the difference between the compared objects is within 10% or 5% of the average value of the compared objects. Unless otherwise specified in the following embodiments of this invention, the quantity of a component or element is implied to mean that the component or element may be one or more, or can be understood as at least one. "At least one" refers to one or more, and "more" refers to at least two.

[0040] In battery system engineering, pressure control and pressure monitoring are core means to ensure normal and safe operation. For liquid batteries, which contain organic liquid electrolytes, under abuse conditions such as overcharging and overheating, the electrolyte decomposes to produce a large amount of flammable gas, causing a sharp increase in internal pressure. Therefore, pressure control mainly focuses on sealing to prevent leakage and explosion-proof pressure relief, while pressure monitoring aims to provide early warning of thermal runaway by detecting abnormal pressure rises. For all-solid-state batteries, since the solid electrolyte and electrode materials have a solid-solid interface, they lack the wetting compensation capability of liquid electrolytes. External pre-tightening forces are needed to maintain tight contact at the interface to improve the contact area and contact effect between the positive and negative electrodes and the solid electrolyte layer. Therefore, the purpose of pressure control for all-solid-state batteries is "pressure-based safety maintenance," which is a fundamental prerequisite for the normal operation of the battery. In addition, because the heat release rate during thermal runaway of sulfide all-solid-state batteries is extremely fast (on the order of seconds), the pressure change response speed is much faster than the temperature change, making pressure monitoring a key means of rapid early warning of thermal runaway. Semi-solid batteries, as a transitional form between the two, contain a certain proportion of liquid electrolyte, which combines the requirements of sealing and leak prevention with the requirement of solid-solid interface constraint. Furthermore, during thermal runaway, the gas production from the decomposition of the solid and liquid phases may overlap in time series, resulting in multi-stage pressure changes. This requires pressure monitoring to have more complex state recognition capabilities.

[0041] However, the pressure monitoring and control methods in related technologies still have the following shortcomings: First, insufficient monitoring accuracy and fault location capability. When a battery module contains a large number of cells, minute pressure changes at the cell level may be masked by module-level pressure fluctuations, making it impossible to identify and locate faulty battery cells in a timely manner. Second, pressure control and safety response are disconnected. After detecting abnormal pressure signals, it is impossible to quickly and specifically isolate or suppress faulty batteries through pressure regulation, and the regulated pressure may also affect the operation of normal battery cells within the battery module.

[0042] This disclosure improves the accuracy of pressure monitoring and control around the battery cells and enhances the speed of response by dispersing multiple battery cells within a battery module and immersing them in different cavities, with the pressure of the fluid medium in each cavity varying independently. For example, when a battery cell in a cavity undergoes volume expansion (such as expansion during charging and discharging or gas generation before thermal runaway), the internal pressure change will be more significant and sensitive than in the overall interconnected system because that cavity contains relatively few battery cells and is isolated from other cavities, facilitating accurate sensor detection. The control system can independently adjust the flow rate or pressure of the fluid medium in that cavity based on pressure feedback, achieving rapid response. Taking an all-solid-state battery as an example, this design ensures the required preload while enabling precise fault location and isolation, preventing fault propagation and improving system stability and safety.

[0043] In this disclosure, a battery cell is the smallest physical unit that directly converts chemical energy into electrical energy, and it is also the most basic "energy container" in a battery system. A battery cell includes a positive electrode, a negative electrode, and an electrolyte layer. During the charging and discharging process of a battery cell, active ions (e.g., lithium ions, sodium ions, etc.) repeatedly insert and extract between the positive and negative electrodes. The electrolyte layer (or a separator layer impregnated with electrolyte) is disposed between the positive and negative electrodes, not only preventing short circuits between the positive and negative electrodes but also allowing active ions to pass through. In this disclosure, the electrolyte layer can be a solid electrolyte layer, a liquid electrolyte layer, or a semi-solid electrolyte layer. This disclosure is not limited in this respect.

[0044] In this disclosure, the shape of the battery cell can be cylindrical, flat, or polygonal. The battery cell can be a hard-cased battery cell (e.g., cylindrical battery, prismatic battery), a pouch battery cell, etc. This disclosure is not limited in this respect.

[0045] In this disclosure, the battery module includes a module housing and multiple battery cells, which are arranged in series and / or in parallel within the module housing. Furthermore, the battery module also integrates intermediate components such as a battery cell fixing structure and a cell management unit (e.g., a voltage / temperature sensor).

[0046] In this disclosure, the battery pack includes a battery casing and battery modules or individual battery cells, which are constructed by combining several battery modules or individual battery cells (through Cell to Pack, CTP technology). The battery pack also integrates peripheral auxiliary systems, such as a Battery Management System (BMS) and a thermal management system.

[0047] In this disclosure, electrical devices that use battery packs as a power source include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft (including airplanes, rockets, spacecraft, etc.).

[0048] The embodiments and examples of this disclosure will now be described in detail with reference to the accompanying drawings.

[0049] Figure 1 This is a perspective view of a battery module provided in some embodiments of the present disclosure, wherein the sidewalls of the module housing are opened to illustrate the internal structure. Figure 1 As shown, the battery module 100 may include multiple battery cells (if the separators 121 and 122 are battery cells, then...). Figure 1In the diagram, 121 and 122 represent individual battery cells (if the separator is not a battery cell, then the battery cell is not shown), and a module housing 110 is provided to house multiple battery cells. The module housing 110 has multiple cavities 111, 112, and 113, each filled with a fluid medium 130. The pressure within each cavity can vary independently. The fluid medium in each cavity immerses a portion of the multiple battery cells, such that at least a portion of the surfaces of the battery cells bears the required given pressure.

[0050] In this embodiment, the module housing 110 is divided into multiple independent cavities 111, 112, and 113. These cavities are physically isolated from each other by separators 121 and 122, allowing the pressure within each cavity to change independently without interference. Pressure changes within the cavities can be caused by the control system actively adjusting the pressure of the fluid medium, or passively by changes in the state of individual battery cells (such as bulging or gas production). Regardless of the source of the pressure change, the pressure independence of each cavity is maintained, and it will not affect other cavities.

[0051] It should be noted that "the pressure within the cavity can change independently" includes two scenarios: First, the cavity has no openings or connecting holes, and the pressure within it changes independently under all circumstances; second, the cavity has a controllable connecting switch on its periphery. When the connecting switch is closed, the pressure within the cavity changes independently; when the connecting switch is open, the cavity can connect with other cavities, and the pressure within the cavity changes independently under specific conditions. If two cavities are physically isolated but always have a connecting channel, the pressure in these two cavities will not change independently but will affect each other.

[0052] In this embodiment, each cavity 111, 112, and 113 is filled with a fluid medium 130, and the fluid medium in each cavity immerses at least one surface of at least one battery cell, such that at least a portion of the surface of each battery cell can withstand the given pressure required for its normal operation. For example, when the separator is not a battery cell, the formed cavity can accommodate one or more battery cells. Figure 1 (not shown in the image) so that the surface of the contained battery cell is immersed in the fluid medium of the cavity. For example, when the battery cell itself acts as a separator 121, its two adjacent cavities 111 and 112 can respectively immerse the two surfaces of the battery cell, in which case these two cavities can accommodate / do not accommodate other battery cells.

[0053] The fluid medium within multiple cavities is used to provide the required given pressure to the surface of the immersed battery cell. This given pressure refers to the pressure required for the battery cell to operate. Specifically, for all-solid-state batteries, the required pressure refers to the external pressure applied to maintain good solid-solid interface contact between the solid electrolyte and the electrodes, which can range from tens to hundreds of megapascals (MPa), or as low as 5 MPa or even around 0.5 MPa or 0.1 MPa. For liquid batteries, the required pressure can be, for example, the external pressure applied to suppress lithium dendrite growth, optimize lithium metal deposition morphology, and improve cycle stability. For semi-solid-state batteries, the required pressure can be, for example, the constraint pressure applied to ensure a certain interface contact and reduce the impact of electrode expansion and contraction while taking into account the performance of the solid-liquid hybrid electrolyte system.

[0054] The embodiments disclosed above significantly improve the accuracy of monitoring and controlling the pressure around the battery cells and the speed of response by dispersing and immersing multiple battery cells in multiple independent cavities and allowing the fluid medium pressure in each cavity to change independently.

[0055] When a battery cell malfunctions (e.g., expansion, thermal runaway gas generation), the technical solution disclosed herein can accurately and quickly identify the specific cavity affected by that battery cell. By independently adjusting the pressure within that cavity, the problem can be addressed or alleviated in a targeted manner without affecting the normal operation of battery cells in other cavities. In contrast, if all battery cells are immersed in the same cavity, the pressure changes caused by the malfunctions of each cell will be mixed and diluted by the fluid in the large-volume cavity, making it difficult to accurately detect the expansion of specific battery cells and impossible to achieve rapid pressure response and adjustment. The technical solution disclosed herein reduces the volume of individual cavities, thereby reducing the number of battery cells immersed in each cavity, or even allowing each cavity to only involve a portion of the surface of a specific battery cell. When a specific battery cell expands or contracts, the pressure within the cavity is more sensitive to that expansion or contraction. This allows for more accurate and rapid location of the cavity experiencing pressure changes and the corresponding battery cell, enabling targeted pressure control and facilitating subsequent tracking, resolution, or mitigation of problems affecting the battery cells in that cavity.

[0056] The embodiments described above are particularly applicable to all-solid-state batteries. All-solid-state batteries have high interfacial resistance due to the solid-solid contact between the solid electrolyte and the electrode plates, and are highly sensitive to contact pressure. Insufficient contact pressure leads to poor interfacial contact, significantly increasing internal resistance and reducing rate performance and cycle life; excessive pressure may cause the brittle solid electrolyte to break or the battery casing to deform. Therefore, all-solid-state batteries typically need to withstand a certain and stable external pressure to operate normally and achieve optimal performance.

[0057] The embodiments disclosed above can provide a precise, independent, and stable external pressure control and monitoring environment for each group or even each all-solid-state battery. Specifically, this disclosure can apply an independently set target pressure to each or each group of all-solid-state battery cells, thereby avoiding the "one-size-fits-all" problem caused by pressure homogenization in traditional large-volume cavities, ensuring that each all-solid-state battery can obtain its specific optimal pressure environment to optimize interface contact and reduce interface impedance. In addition, this disclosure can monitor and dynamically compensate for the minute dimensional changes that occur in all-solid-state batteries during battery charge-discharge cycles in real time, thereby ensuring that all-solid-state batteries remain in a stable pressure state throughout their entire life cycle, effectively suppressing interface performance damage or even failure caused by pressure fluctuations. Similarly, this disclosure can also identify poor interface contact, abnormal local expansion, or potential precursors to thermal runaway earlier and more accurately. Once an abnormal pressure in a cavity is detected (such as a sudden increase or decrease in pressure), the system can immediately adjust the pressure of that cavity and / or diagnose and treat the corresponding identified battery cells without affecting other normally operating all-solid-state batteries. Of course, these effects are also applicable to other types of batteries besides all-solid-state batteries.

[0058] In some embodiments, the sidewalls (i.e., separators) of the plurality of cavities may include at least one of the surfaces of battery cells or separators. For example, Figure 1 The multiple separators 121 and 122 within the cavity can be the battery cell itself, individual separators, or a combination of both. When the sidewalls of multiple cavities are separators, such as... Figure 2 As shown, in the module housing 210, partitions 221 and 222 are respectively provided between cavities 211 and 212, and between cavities 212 and 213. These partitions physically isolate the internal space of the module housing, giving each cavity an independent boundary, thereby ensuring that the pressure of the fluid medium in each cavity can change independently without interference. Each cavity 211, 212, and 213 can accommodate one or more battery cells 240. In this case, all surfaces of the battery cell except for the surface used for fixing are immersed in the fluid medium of the same cavity. This design facilitates the formation of multiple independent cavity spaces. When the sidewalls of multiple cavities are battery cells, such as... Figure 3As shown, in the module housing 310, battery cells 321 and 322 are respectively disposed between cavities 311 and 312, and between cavities 312 and 313, thereby utilizing the surface of the battery cells as the sidewalls of the cavities. In this case, each cavity can accommodate one or more battery cells; for example, cavity 311 accommodates two battery cells 340, and cavity 313 accommodates one battery cell 340. Alternatively or additionally, the cavities may not contain any battery cells; for example, cavity 312 does not contain any battery cells, and the cavity only immerses the surfaces of the battery cells 321 and 322 that serve as its sidewalls. This design not only simplifies the internal structure of the module and reduces the number of parts, but also effectively utilizes the structural strength and fixing method of the battery cells themselves to maintain the sealing of the cavities. It should be understood that the sidewalls of multiple cavities may include a combination of both battery cells and separators. For example, the sidewalls of some cavities in multiple cavities may be battery cells, and the sidewalls of some cavities may be separators. For example, the left wall of a cavity is a battery cell, and the right wall is a separator.

[0059] In some embodiments, the battery cells or separators serving as the sidewalls of the cavity can be perpendicular to the arrangement direction of the battery cells, such as... Figures 1 to 3 As shown, the arrangement direction of the battery cells can also be at a certain angle. Additionally, the battery cells or separators that serve as the sidewalls of the cavity can be parallel to the arrangement direction of the battery cells. That is, multiple rows of battery cells are arranged inside the module housing, and the cavities containing each row of battery cells are separated by battery cells or separators.

[0060] It should be understood that this disclosure does not limit the number or arrangement of cavities within the module housing; multiple cavities can be arranged as follows: Figures 1 to 3 The linear arrangement shown can also be arranged in a grid pattern, etc., as long as the pressure within each cavity can change independently. Furthermore, it should be understood that this disclosure does not limit the size, shape, or number of battery cells immersed in the multiple cavities. In a battery module, the cavities can be the same or different in size, the same or different in shape, and the same or different in number of battery cells immersed in each cavity.

[0061] Figure 4 This is a plan view of a battery module 400 provided in some embodiments of this disclosure. Figure 4In this module, multiple battery cells 440 are arranged within a module housing 410, dividing the interior of the housing 410 into multiple cavities 411. In other words, the sidewalls of the cavities 411 are formed by the surfaces of the battery cells 440, and the two opposite surfaces of each battery cell are immersed in fluid media within adjacent cavities 411. In this embodiment, since the pressure in each cavity can vary independently, the pressure on both sides of each battery cell can be individually controlled and monitored. For example, if the pressure in a cavity suddenly increases, it means that at least one battery cell immersed in that cavity has expanded or produced gas. In this case, the fluid volume in that cavity can be adjusted accordingly to restore it to normal pressure. As another example, if the pressure on the two sides of a battery cell is different, the pressure on the adjacent side of the cavity can be adjusted to maintain consistent pressure on both sides of the battery cell.

[0062] In some embodiments, the surfaces of multiple battery cells are sealed to the inner surface of the module housing, allowing the pressure within each of the multiple cavities to vary independently. For example... Figure 4 As shown, when the separators of multiple cavities are battery cells, the peripheral surface of the battery cell (i.e., the surface intersecting the first surface 441 and the second surface 442) can be sealed to the inner surface of the module housing 410 by applying sealant or setting a sealing gasket, thereby ensuring that each cavity is independent and does not affect the others. It should be understood that the sealing connection here can be a seal between the entire peripheral surface of the battery cell and the inner surface of the module housing, or it can be a seal only between a portion of the peripheral surface of the battery cell along its arrangement direction L and the inner surface of the module housing. The scope of the sealing connection is not limited here, as long as the pressure in each cavity can change independently.

[0063] In some embodiments, such as Figure 4 As shown, the battery cell 440 may include a first surface 441 and a second surface 442 opposite to each other. The first surface 441 and the second surface 442 are respectively immersed in the fluid medium of the two cavities 411, and the other surfaces of the battery cell 440 other than the first surface 441 and the second surface 442 are not immersed in the fluid medium 430 of the two cavities 411. That is, only the first surface 441 and the second surface 442 of the battery cell 440 are exposed to the fluid medium 430 of the adjacent cavities, while the remaining surfaces are completely sealed to the inner surface of the module housing 410 so as not to be immersed in the fluid medium 430.

[0064] In the above-described implementation, the pressure applied by the fluid medium acts only on two opposing surfaces of the battery cell, without affecting other surfaces. In other words, the battery cell only bears fluid pressure on two opposing surfaces, while the remaining surfaces are unaffected, thus ensuring that the magnitude and direction of the internal forces of the battery cell are not additionally disturbed by the pressure on the two opposing surfaces. This is particularly advantageous for all-solid-state batteries. All-solid-state batteries require external pressure to maintain contact between the electrodes and the solid electrolyte during operation, thus necessitating pressure substantially perpendicular to the electrodes and solid electrolyte.

[0065] In some other embodiments, the portion of the peripheral surface of the battery cell that is not used for sealing connection along the arrangement direction L of the battery cells may also be immersed in a fluid medium.

[0066] In some embodiments, the pressure exerted on the first surface 441 and the second surface 442 by the fluid medium 430 is substantially perpendicular to the electrode plates inside the battery cell. This helps maintain electrical contact between the electrode plates, reduces internal resistance, and also helps reduce the risk of the active material layer on the electrode plates detaching due to volume changes such as expansion and contraction during charging and discharging. This is particularly advantageous for all-solid-state batteries, which require external pressure during operation to maintain solid-solid contact between the electrodes and the solid electrolyte. Therefore, they especially require pressure substantially perpendicular to the electrodes and the solid electrolyte to tightly bond the electrodes and the solid electrolyte together.

[0067] In some embodiments, the pressure applied by the fluid medium 430 to the first surface 441 is the same as the pressure applied by the fluid medium 430 to the second surface 441. When the pressures on the two surfaces of a battery cell are different, the pressure on the adjacent side cavity of the battery cell can be adjusted to maintain consistent pressure on both sides of the battery cell. If the fluid medium applies different pressures to the first and second surfaces of the battery cell, the battery cell will experience net force (resultant force is not zero) and bending moment. This can cause the battery cell to bend, twist, or misalign the internal electrode plates. For pouch batteries, this may lead to bulging or cracking; for hard-shell batteries, it may lead to casing deformation or seal failure. In addition, it can cause bending and misalignment of the fixing and sealing structures between the battery cell and the module housing, resulting in battery cell fixing and sealing failure, independent cavity communication, fluid medium leakage, and other problems. Maintaining equal pressure on both sides ensures that the battery cell is in a state of static equilibrium, only experiencing uniform compressive stress, thereby protecting the internal and external structures of the battery cell.

[0068] In some embodiments, such as Figure 4As shown, the module housing 410 may include a top wall 410-1 and a bottom wall 410-2. The top wall 410-1 is provided with a plurality of first grooves 451, and the bottom wall is provided with a plurality of second grooves 452 that are disposed opposite to the plurality of first grooves 451. Further, as... Figure 5 As shown, the battery cell 440 (on its peripheral surface opposite the top and bottom walls) may include a first sealing edge 443 and a second sealing edge 444, which are respectively embedded in a first groove 451 and a second groove 452 arranged opposite to each other. The cooperation of the first and second sealing edges and the corresponding grooves facilitates both fixing the battery cell within the module housing and setting a sealing structure thereon, thereby sealing the surface of the battery cell to the inner wall of the module housing. Furthermore, creating grooves in the module housing avoids occupying space within the module housing, thus achieving a compact module design.

[0069] Alternatively or additionally, at least one of a third sealing edge (not shown in the figure) and a fourth sealing edge (not shown in the figure) may be provided on the peripheral surface of the side wall 410-3 facing and / or away from the module housing of the battery cell 444. Correspondingly, the battery cell has a corresponding groove on at least one side wall of the module housing located between the top wall and the bottom wall for fitting at least one of the third sealing edge and the fourth sealing edge.

[0070] In other embodiments, at least one of the first, second, third, and fourth sealing edges can be directly and sealed to the inner surface of the module housing by applying adhesive and setting a sealing gasket, without setting a groove on the inner surface of the module housing.

[0071] In some embodiments, such as Figure 4 and Figure 5 As shown, the first sealing edge 443 and the second sealing edge 444 are fitted into the oppositely arranged first groove 451 and second groove 452 by their respective clamping members 460. Figure 6 As shown, the clamping member 460 may include a clamping space 461 for accommodating the first sealing edge 443 or the second sealing edge 444, and a sidewall 462 forming the clamping space 461. The sidewall 462 of the clamping member 460 abuts against the clamped first sealing edge 443 or the second sealing edge 444 to fix the clamped first sealing edge or the second sealing edge. The abutment between the sidewall of the clamping member and the clamped first sealing edge or the second sealing edge can be a line contact or a surface contact to adapt to different sealing requirements and stress conditions. In the above embodiment, using the clamping member to snap the battery sealing edge into the housing groove improves the reliability of battery cell fixation and facilitates improved sealing between cavities and the independence of pressure in each cavity.

[0072] In some embodiments, when the clamping space 461 accommodates the first sealing edge 443 or the second sealing edge 444, the sidewall 462 of the clamping member elastically abuts against the clamped first sealing edge or the second sealing edge. For example... Figure 5 As shown, the clamping component 460 is designed with a resilient reset function. Without external force, the clamping component automatically returns to the clamping state in the direction of arrow R. This self-locking or resilient reset mechanism ensures that the clamping component remains clamped after assembly, eliminating the need for an additional locking mechanism. Simultaneously, the clamping force is sufficient to prevent relative movement between the clamped object (i.e., the first or second sealing edge) and the clamping component in most or all cases. This guarantees that during battery module operation, even under vibration, impact, or internal pressure fluctuations, the sealing edge will not loosen or shift, thereby maintaining the reliability of the battery cell fixation and the sealing integrity of the cavity.

[0073] In this embodiment, when assembling the clamping component, an installation device is used to open the clamping component, and the clamped edge banding is placed inside the clamping component. Finally, the device is removed to complete the assembly. This assembly method utilizes the elastic properties of the clamping component. An external device temporarily overcomes the elastic force to open the clamping space. After the edge banding is placed in, the external force is removed, and the clamp automatically resets and tightens.

[0074] In some embodiments, such as Figure 4 and Figure 5 As shown, the clamping member 460 is sealed to the embedded first groove 451 or second groove 452, and also sealed to the clamped first sealing edge 443 or second sealing edge 444, so that the pressure in each cavity of the multiple cavities 411 can change independently. It can be understood that the clamping member only needs to meet the assembly requirements; the material and shape are not limited. This means that this embodiment does not limit the specific material (such as metal, engineering plastic, composite material, etc.) and specific geometry (such as C-shaped, U-shaped, L-shaped, etc.) of the clamping member, as long as it can achieve the functions of clamping, sealing, and elastic reset, it can be applied to this technical solution. This flexibility allows designers to choose the most suitable clamping form according to specific application scenarios, cost requirements, or manufacturing processes. In some examples, as mentioned above, the clamping member 460 can be elastic, thereby elastically abutting the sealing edge. Alternatively or additionally, the clamping element can be rigid and configured to interference fit with the clamped sealing edge and the embedded groove, thereby achieving fixation of the battery cell while maintaining the seal between cavities and independence from pressure changes. In this case, sealing structures can be added inside and outside the clamping element to increase the seal between cavities. Alternatively or additionally, the clamping element can be a highly elastic material such as rubber, which achieves fixation of the battery cell while maintaining the seal between cavities and independence from pressure changes.

[0075] In some embodiments, such as Figure 5As shown, the clamping member 460 can completely cover the surface of the battery cells along the arrangement direction L of the battery cells, thereby preventing that portion of the battery cell surface from being submerged by the fluid medium. Alternatively, the clamping member can also only partially cover the surface of the battery cells along the arrangement direction of the battery cells, with the remaining portion of the surface being hermetically connected to the inner surface of the module housing, thereby preventing that portion of the battery cell surface from being submerged by the fluid medium.

[0076] In some embodiments, to achieve active control of the fluid medium within each cavity, the module housing may be provided with multiple mounting holes communicating with multiple cavities respectively. Each mounting hole is equipped with a fluid control valve, which controls the flow of the fluid medium from or into the connected cavity. For example... Figure 4 As shown, multiple mounting holes 453 are provided on the top wall 410-1 of the module housing 410 (or alternatively on the side wall 410-3 of the module housing), each mounting hole corresponding to an independent cavity. Each of the mounting holes 453 is equipped with a fluid control valve 470. Each fluid control valve is sealed to its corresponding cavity 411, forming an independent fluid channel. When it is necessary to increase the pressure in a cavity, the control system opens the corresponding fluid control valve to inject fluid medium into the cavity; when it is necessary to decrease the pressure, it opens the corresponding fluid control valve to discharge the fluid medium. Since each mounting hole and fluid control valve communicates with only one cavity, the pressure of each cavity can be adjusted independently without interference.

[0077] In some embodiments, the center line of the mounting hole 453 may coincide with the center line of the spacing between two adjacent battery cells 440. In some examples, the spacing between the two battery cells may be 5mm to 10mm, for example, 6mm, 6.5mm, 7mm, etc., or it may be other sizes, for example, less than 5mm or more than 10mm.

[0078] In some embodiments, such as Figure 4 and Figure 5 As shown, the tabs 445 of the battery cell 440 are not submerged in the fluid medium 430 within the module housing. This not only prevents damage to the tabs from the fluid medium, which may apply high pressure, but also prevents corrosion of the tabs by substances in the fluid medium. For example, as... Figure 4As shown, the module housing 410 includes a housing wall, through which the electrode tabs pass (e.g., the side wall 410-3 of the module housing) to be positioned outside the fluid medium. In this case, additionally, a sealant or similar material can be applied between the electrode tabs and the housing wall to prevent the electrode tabs from contacting the fluid medium inside the module housing. The electrode tabs can be entirely contained within the housing wall, which not only prevents contact with the fluid medium inside the module housing but also prevents damage to the electrode tabs from the fluid medium outside the module housing. Alternatively or additionally, the electrode tabs can also extend beyond the housing wall, in which case the electrode tabs can be cooled by the fluid medium outside the module housing. In this case, if substances in the fluid medium outside the module housing are harmful to the electrode tabs, a sealing cap or similar component can be attached to the electrode tabs to isolate the electrode tabs from the fluid medium outside the module housing.

[0079] In some embodiments, a heat insulation structure (not shown in the figure) is provided between two adjacent battery cells in a plurality of battery cells. For example, a heat insulation structure can be provided on the first surface 441 and / or the second surface 442 of the battery cell 440 to achieve thermal isolation between battery cells and prevent the heat generated by one battery cell from being transferred to other battery cells.

[0080] In some embodiments, the fluid medium within the cavity can provide a pressure higher than atmospheric pressure to the battery cells. For example, this pressure can be in the range of 1–20 MPa, preferably 1–15 MPa, more preferably 8–12 MPa; a typical example could be 10 MPa. This pressure higher than atmospheric pressure can constrain the electrode plates, the solid electrolyte interface, and the outer surface of the cell casing. This pressure also inhibits the entry of air and moisture into the battery system, reducing the risk of harmful gases being generated from contact between the solid electrolyte, especially sulfide solid electrolytes, and moisture.

[0081] In some embodiments, the fluid medium within the module housing may include a liquid, such as an insulating liquid with good heat dissipation properties. The liquid within the module housing can not only apply the required given pressure to the surface of the battery cell, but also function as a thermal runaway protection medium and a temperature control medium. For example, when a battery cell experiences thermal runaway, the heat, ejected material, and high-temperature gases released by the battery first come into contact with the surrounding fluid medium. The fluid medium absorbs some of the transient heat through its heat capacity and / or phase change enthalpy (this heat can be discharged by opening a fluid control valve), thereby slowing down or preventing the spread of thermal runaway.

[0082] In some embodiments, the fluid medium within the module housing may include one or more of silicone oil, mineral oil, hydrocarbon synthetic oil, ester synthetic oil, fluorinated liquid, etc. These fluid media ensure insulation and pressure stability, especially in environments with pressures exceeding atmospheric pressure within the module housing. They also reduce the likelihood of external air and moisture entering the module housing, making them particularly suitable for moisture-sensitive non-aqueous electrolyte batteries. Specifically, for sulfide solid-state batteries, the aforementioned fluid media also help reduce the risk of harmful gases such as hydrogen sulfide being generated from contact between the sulfide electrolyte and moisture. In some examples, the fluorinated liquid may include at least one of ethyl nonafluorobutyl ether, perfluorohexane, etc. Hydrocarbon synthetic oils may include at least one of polyalphaolefins, alkylbenzenes, polybutene, etc. Esters synthetic oils may include at least one of polyol esters, diesters, etc. It should be understood here that the fluid medium described in this disclosure is not limited to the examples above, but may also include other dielectric liquids known in the art or developed in the future that have the required electrical insulation and chemical stability and are compatible with the module housing and battery assembly, such as other saturated or unsaturated hydrocarbons (e.g., C14-C50 alkanes, alkenes), aromatic hydrocarbons (e.g., dialkylbenzenes, cyclohexylbenzenes), esters, ethers, ketones, halogenated hydrocarbons (e.g., hydrofluoroethers) or any combination thereof.

[0083] In some embodiments, individual battery cells may release harmful substances under certain conditions. The fluid medium within the module housing may include additives capable of neutralizing these harmful substances generated by the battery cells. For example, batteries with electrolytes including sulfides may release sulfur-containing toxic substances under certain conditions, especially during thermal runaway, releasing large amounts of sulfur-containing toxic fumes such as hydrogen sulfide, sulfur dioxide, and sulfur vapor. In such cases, at least one substance selected from the following can be added to the fluid medium: diisooctyl monoethanolamine, zinc isooctanoate, amino-modified perfluoropolyether, chloride, sulfate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, or alkaline inorganic substances, to neutralize the sulfur-containing toxic fumes and improve the safety performance of the battery system. In some examples, chlorides may include ferric chloride, etc. Sulfates may include ferric sulfate, etc. Alkaline inorganic substances may include at least one of the following: hydroxides, oxides, carbonates, or bicarbonates of alkali metals or alkaline earth metals. The alkaline inorganic compounds may include at least one of the following: sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, lithium hydroxide, etc.; oxides may include at least one of the following: calcium oxide, magnesium oxide, sodium oxide, etc.; and carbonates may include at least one of the following: sodium carbonate, potassium carbonate, calcium carbonate, etc. It should be understood that the additives disclosed herein are not limited to the examples above, and may also include other substances known in the art or developed in the future that can achieve the same or similar harmless treatment functions.

[0084] Figure 7 This is a schematic diagram of a battery pack provided in some embodiments of this disclosure. For example... Figure 7 As shown, the battery pack 700 may include one or more battery modules 710. The battery module 710 is... Figures 1 to 6 The battery module 100 or 400 is described in the text.

[0085] In some embodiments, such as Figure 7 As shown, the battery pack 700 also includes a battery housing 720 for housing a battery module 710, wherein the battery housing is filled with a fluid medium 730, and the battery module 710 is at least partially immersed in the fluid medium 730 within the battery housing 720. The fluid medium 730 in the battery housing 720 can interact with the fluid medium in the module housing (such as...) Figures 1 to 6 The composition of the fluid medium 130 or 430 described herein may be the same as or different from that of the fluid medium 730 in the battery housing 720. The composition, function, and other characteristics of the fluid medium 730 in the battery housing 720 are the same as those of the fluid medium in the module housing (e.g., ...). Figures 1 to 6 The fluid medium 730 described herein (130 or 430) is similar and will not be described in detail here. In some examples, the fluid medium 730 in the battery housing 720 may be selected to be the same as the fluid medium in the module housing (e.g., Figures 1 to 6 The fluid medium (130 or 430) described herein has the same composition, for example, both being silicone oil, or both consisting of the same two substances (exemplarily, silicone oil and ethyl nonafluorobutyl ether), the relative amounts of which may be the same or different. In other examples, the fluid medium in the battery casing and the fluid medium in the module casing may have different compositions. For example, the fluid medium in the battery casing may be one of silicone oil, mineral oil, hydrocarbon synthetic oil, ester synthetic oil, fluorinated liquid, etc., while the fluid medium in the module casing may be another of silicone oil, mineral oil, hydrocarbon synthetic oil, ester synthetic oil, fluorinated liquid, etc.

[0086] In the above embodiments, the fluid control valves corresponding to each cavity in the module housing can control the fluid medium in the module housing to flow out of the connected cavity into the battery housing, or control the fluid medium in the battery housing to flow into the connected cavity, thereby controlling the pressure changes of each cavity in the module housing.

[0087] This disclosure also provides an electrical device including a battery pack according to one or more of the foregoing embodiments of this disclosure, the battery pack being used to provide electrical energy.

[0088] The basic principles of this disclosure have been described above with reference to specific embodiments. It should be noted that the advantages, benefits, and effects mentioned in the embodiments of this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations; these details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details. It should also be noted that in the apparatus and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered equivalent solutions of this disclosure.

[0089] Furthermore, words such as “including,” “contains,” and “has” are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The words “or” and “and” as used here refer to the words “and / or,” and are used interchangeably with them unless the context explicitly indicates otherwise. The word “such as” as used here refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0090] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery module, comprising: Multiple battery cells; as well as The module housing accommodates the multiple battery cells. The module housing has multiple cavities filled with a fluid medium, and the pressure in each cavity can vary independently. In each of the cavities, a fluid medium immerses a portion of the plurality of battery cells, such that at least a portion of the plurality of surfaces of the battery cells are subjected to a given pressure.

2. The battery module according to claim 1, wherein the sidewalls of the plurality of cavities include at least one of the surfaces of the battery cells or separators.

3. The battery module according to claim 1, wherein, The multiple battery cells are arranged inside the module housing, dividing the interior of the module housing into multiple cavities.

4. The battery module according to claim 3, wherein, The surfaces of the multiple battery cells are sealed to the inner surface of the module housing, so that the pressure in each of the multiple cavities can change independently.

5. The battery module according to claim 3, wherein, The battery cell includes a first surface and a second surface opposite to each other. The first surface and the second surface are respectively immersed in the fluid medium of two cavities, and the other surfaces of the battery cell other than the first surface and the second surface are not immersed in the fluid medium of the two cavities.

6. The battery module according to claim 5, wherein, The pressure from the fluid medium on the first and second surfaces is perpendicular to the electrode plates inside the battery cell.

7. The battery module according to claim 3, wherein, The module housing includes a top wall and a bottom wall. The top wall has a plurality of first grooves, and the bottom wall has a plurality of second grooves that correspond one-to-one with the first grooves. The battery cell includes a first sealing edge and a second sealing edge, which are respectively embedded in the first groove and the second groove that are arranged opposite to each other.

8. The battery module according to claim 7, wherein, The first edge seal and the second edge seal are embedded in the oppositely arranged first groove and second groove by their respective clamping members, wherein the clamping member includes a clamping space for accommodating the first edge seal or the second edge seal and a side wall forming the clamping space, and the side wall of the clamping member abuts against the clamped first edge seal or the clamped second edge seal to fix the clamped first edge seal or the clamped second edge seal.

9. The battery module according to claim 8, wherein, When the clamping space accommodates the first or second sealing edge, the sidewall of the clamping member elastically abuts against the clamped first or second sealing edge.

10. The battery module according to claim 8, wherein, The clamping member is sealed to the embedded first or second groove and to the clamped first or second sealing edge, so that the pressure in each of the plurality of cavities can change independently.

11. The battery module according to any one of claims 1 to 10, wherein, The battery cell includes a first surface and a second surface opposite to each other, and the pressure applied by the fluid medium to the first surface is the same as the pressure applied by the fluid medium to the second surface.

12. The battery module according to any one of claims 1 to 10, wherein, The module housing is provided with multiple mounting holes that communicate with the multiple cavities respectively. Each of the multiple mounting holes is provided with a fluid control valve, which is used to control the fluid medium to flow out of or into the connected cavity.

13. The battery module according to any one of claims 1 to 10, wherein, The module housing includes a housing wall, through which the tabs pass to be positioned outside the fluid medium.

14. The battery module according to any one of claims 1 to 10, wherein, A heat insulation structure is provided between two adjacent battery cells in the plurality of battery cells.

15. The battery module according to any one of claims 1 to 10, wherein, The fluid medium is a liquid.

16. The battery module according to claim 15, wherein, The fluid medium includes at least one of silicone oil, mineral oil, hydrocarbon synthetic oil, ester synthetic oil, and fluorinated liquid.

17. The battery module according to any one of claims 1 to 10, wherein, The fluid medium includes additives capable of neutralizing harmful substances generated by the battery cells.

18. The battery module according to claim 17, wherein, The additives include at least one of the following: diisooctyl monoethanolamine, zinc isooctanoate, amino-modified perfluoropolyether, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, chloride, sulfate, and basic inorganic substances.

19. The battery module according to any one of claims 1 to 10, wherein, The battery cell includes a solid electrolyte.

20. The battery module according to claim 19, wherein, The electrolyte in each battery cell is a solid electrolyte.

21. The battery module according to any one of claims 1 to 10, wherein, The given pressure is higher than atmospheric pressure.

22. A battery pack, characterized in that, include: The battery module according to any one of claims 1-21.

23. The battery pack of claim 22, further comprising a battery housing accommodating the battery module, wherein, The battery casing is filled with a fluid medium, and the battery module is at least partially immersed in the fluid medium in the battery casing; the fluid medium in the battery casing may have the same or different composition as the fluid medium in the module casing.

24. An electrical appliance, characterized in that, Includes the battery pack according to claim 22 or 23, the battery pack being used to provide electrical energy.

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