Battery module, battery pack and electric device

Abstract

This application provides a battery module, battery pack, and electrical device, including an end cap assembly comprising an outer end cap and an inner end cap, which are spaced apart. A pre-tightening structure is disposed between the outer and inner end caps to adjust the pre-tightening force on the inner end cap according to the pressure applied to it. With the pre-tightening structure between the outer and inner end caps, during use, the battery cells may expand, causing pressure to be applied to the inner end cap. The pre-tightening structure can then adjust the pre-tightening force on the inner end cap in real time according to the magnitude of this pressure, ensuring that the battery module operates within the optimal pressure range, thus protecting the battery cells and extending their lifespan.

Description

Technical Field

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

[0002] All-solid-state lithium metal batteries offer higher energy density, lower self-discharge rate, and better safety, making them a promising technology for next-generation energy storage systems. They hold promise for large-scale application in electrochemical energy storage systems and electric vehicles. However, replacing liquid electrolytes with solid electrolytes presents inherent challenges, including poor interfacial contact between lithium metal and the solid electrolyte, low ionic conductivity, high interfacial resistance, and the inevitable brittle cracking along grain boundaries in ceramic electrolytes. Preload control is crucial during the assembly of all-solid-state lithium metal batteries. Appropriate preload ensures good contact between battery cells, thereby improving battery conductivity and overall performance. Excessive preload may lead to battery structural damage, internal short circuits, shortened battery life, and reduced sealing performance; while insufficient preload may cause poor contact and structural loosening, affecting the battery's charge / discharge performance and physical stability.

[0003] Therefore, it is particularly important to know how to control the battery preload. Utility Model Content

[0004] The purpose of this application is to provide a battery module, battery pack, and electrical device that can provide sufficient preload.

[0005] In a first aspect, embodiments of this application provide a battery module, including: an end cap assembly, including an outer end cap and an inner end cap, the outer end cap and the inner end cap being spaced apart; and a pre-tightening structure, the pre-tightening structure being disposed between the outer end cap and the inner end cap, to adjust the pre-tightening force on the inner end cap according to the pressure received by the inner end cap.

[0006] In the above process, a pre-tightening structure is set between the outer end cover and the inner end cover. During the use of the battery module, the battery cells will expand and other phenomena will occur. After the battery cells apply pressure to the inner end cover, the pre-tightening structure can adjust the pre-tightening force on the inner end cover in real time according to the magnitude of the pressure, so as to ensure that the battery module works in the optimal pressure range, thereby protecting the battery cells and extending their life.

[0007] In some embodiments, the pre-tightening structure includes a hydraulic jack, the output end of which contacts the outer end cap or the inner end cap.

[0008] During the above process, the hydraulic jack contacts the outer end cover and the inner end cover respectively. The hydraulic jack can apply sufficient pre-tightening force to the inner end cover, effectively suppressing the expansion of the battery cells and ensuring that the battery module works in the optimal pressure range, thereby protecting the battery cells and extending their lifespan.

[0009] In some embodiments, a plurality of hydraulic jacks are provided, and the plurality of hydraulic jacks are spaced apart between the outer end cover and the inner end cover. This ensures more uniform force distribution on the battery cells, effectively protects the battery cells, extends their service life, and improves the safety performance of the battery module.

[0010] In some embodiments, the inner end cap is provided with a first groove, and at least a portion of the structure of the hydraulic jack is disposed in the first groove.

[0011] In the above process, the first groove can be adapted to part of the structure of the hydraulic jack to limit the hydraulic jack, ensure the stability of the hydraulic jack between the outer end cover and the inner end cover, and effectively suppress the expansion of the battery cell.

[0012] In some embodiments, the outer end cap is provided with a second groove, and at least a portion of the structure of the hydraulic jack is disposed in the second groove.

[0013] In the above process, the second groove can be adapted to part of the structure of the hydraulic jack to limit the hydraulic jack, ensure the stability of the hydraulic jack between the outer end cover and the inner end cover, and effectively suppress the expansion of the battery cell.

[0014] In some embodiments, the pre-tightening structure further includes an oil pipe, the outer end cap is provided with a mounting hole, one end of the oil pipe is connected to the hydraulic jack, and the other end passes through the mounting hole. This ensures a more compact overall structure for the battery module and improves space utilization.

[0015] In some embodiments, the battery module further includes an end plate located on the side of the inner end cover opposite to the outer end cover, and the end plate is spaced apart from the inner end cover.

[0016] In some embodiments, the battery module further includes a enclosure assembly, which is connected to the outer end cap and the end plate respectively to enclose and form a receiving cavity.

[0017] In some embodiments, the battery module further includes a battery cell disposed in the receiving cavity.

[0018] In some embodiments, the battery module further includes a CCS component, which is connected to the individual battery cells and is used to collect information from the individual battery cells.

[0019] Secondly, this application also provides a battery pack, including the battery module as described in any of the above claims.

[0020] Since the battery pack provided in the second aspect includes the battery module, the battery pack has all the technical effects of the battery module, which will not be elaborated here.

[0021] Thirdly, this application also provides an electrical device including the battery pack described above.

[0022] Since the electrical equipment provided by the third party includes a battery pack, the electrical equipment has all the technical effects of the battery pack, which will not be elaborated here.

[0023] Other features and advantages of this application will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the above-described techniques of this application.

[0024] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the battery module provided in an embodiment of this application;

[0027] Figure 2 This is an exploded view of the battery module provided in an embodiment of this application;

[0028] Figure 3 This is a partial structural diagram of the battery module provided in this application.

[0029] Figure Labels

[0030] 10. End cap assembly; 101. Outer end cap; 102. Inner end cap; 1021. First groove; 20. Pre-tightening structure; 30. End plate; 40. Enclosure assembly; 401. Top cover; 402. Bottom cover; 403. Side plate; 50. Battery cell; 60. CCS assembly; 70. Separator. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0032] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0033] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0034] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or a point connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0035] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0036] Example

[0037] In solid-state batteries, the solid electrolyte replaces the liquid electrolyte. Its rigid solid-solid interface makes it prone to microscopic contact gaps between the positive and negative electrodes and the electrolyte, easily leading to poor interfacial contact. This poor contact significantly reduces ion conduction efficiency and increases interfacial impedance (by 1-2 orders of magnitude compared to liquid batteries). To optimize internal contact, precise preload (typically 10-20 MPa) must be applied during module assembly. Insufficient preload results in inadequate interfacial contact, hindered ion transport, and decreased charge / discharge performance. Excessive preload can cause solid electrolyte rupture (e.g., oxide brittle fracture), electrode structure damage, and even internal short circuits and reduced cycle life. While existing liquid batteries use foam in the module to provide cushioning (applying a micro-pressure of approximately 0.1-0.5 MPa), this pressure is far lower than that required for solid-state batteries, and the pressure cannot be adjusted in real-time during use, failing to meet the requirement for tight interfacial contact. In other words, if a foam solution is used, the following disadvantages will exist: foam can only provide very little force, which is insufficient to improve the reaction contact interface of solid-state batteries; foam is prone to permanent plastic deformation, which leads to the loss of preload; and a large clamping force needs to be established during the assembly process, which increases the difficulty of production and assembly.

[0038] In view of this, such as Figures 1-3 As shown, in a first aspect, this application provides a battery module, including: an end cap assembly 10 and a pre-tightening structure 20. The pre-tightening structure 20 is connected to the end cap assembly 10 and can continuously apply sufficient pre-tightening force to the end cap assembly 10 to ensure good contact, which is beneficial to the charging and discharging performance of the battery module.

[0039] Specifically, the end cap assembly 10 includes an outer end cap 101 and an inner end cap 102, the outer end cap 101 and the inner end cap 102 being spaced apart; and a pre-tightening structure 20, which is disposed between the outer end cap 101 and the inner end cap 102 to adjust the pre-tightening force on the inner end cap 102 according to the pressure received by the inner end cap 102.

[0040] For example, the pre-tightening structure 20 is disposed between the outer end cover 101 and the inner end cover 102, mainly to provide pre-tightening force for the battery cell 50 so that the battery cells 50 can fit together; and the outer end cover 101 is located further away from the battery cell 50 relative to the inner end cover 102, and can be used to form part of the housing of the battery module.

[0041] It is understood that after the pre-tightening structure 20 acts on the inner end cover 102, it can apply a uniform pre-tightening force to the battery cell 50. That is, the battery cell 50 will not tilt after being subjected to the pre-tightening force (i.e., under ideal conditions, the force-bearing surface of the battery cell 50 is parallel to the surface of the outer end cover 101).

[0042] In the above implementation process, a pre-tightening structure 20 is provided between the outer end cover 101 and the inner end cover 102. During the use of the battery module, the battery cells 50 will expand, and the battery cells 50 will apply pressure to the inner end cover 102. The pre-tightening structure 20 can adjust the pre-tightening force on the inner end cover 102 in real time according to the magnitude of the pressure, so as to ensure that the battery module works in the optimal pressure range, thereby protecting the battery cells 50 and extending their life.

[0043] like Figures 2-3 As shown, the pre-tightening structure 20 includes a hydraulic jack, the output end of which contacts the outer end cover 101 or the inner end cover 102. For example, the hydraulic jack is a thin hydraulic structure, which can be a commercially available structure or another, as long as it can adjust the pre-tightening force on the battery cell 50 in real time.

[0044] Understandably, the thin hydraulic structure has advantages such as compact size, large clamping force (10-70MPa) and high control precision. It can calculate the expansion of the battery cell 50 through the BMS (Battery Management System) software based on the temperature monitored during use and implement real-time control through hydraulic components, so that the battery cell 50 can work in the optimal pressure range.

[0045] Meanwhile, since the pressure of the hydraulic top is adjustable, the pressure of the pre-stacking step can be reduced during the battery module production and assembly process, and the complexity of tooling design and difficulty of box insertion can be reduced, making it easy to manufacture. Furthermore, based on the compact structural dimensions of the hydraulic top, the structure of the outer end cover 101 and the inner end cover 102 can be modified to match the application of battery modules of different sizes.

[0046] During the above process, the hydraulic jack contacts the outer end cover 101 and the inner end cover 102 respectively. The hydraulic jack can apply sufficient pre-tightening force to the inner end cover 102, push the inner end cover 102 to squeeze the battery cell 50, effectively suppress the expansion of the battery cell 50, ensure that the battery module works in the optimal pressure range, and play a role in protecting the battery cell 50 and extending its life.

[0047] In some embodiments, a plurality of hydraulic jacks are provided, and the plurality of hydraulic jacks are spaced apart between the outer end cover 101 and the inner end cover 102. For example, two hydraulic jacks are provided, spaced apart, and their positions may both be located at the horizontal center line of the inner end cover 102. This ensures that the battery cell 50 is subjected to more uniform force, effectively protects the battery cell 50, extends its service life, and improves the safety performance of the battery module.

[0048] Please refer to again Figure 2 and Figure 3The inner end cap 102 is provided with a first groove 1021, and at least a part of the structure of the hydraulic top is disposed in the first groove 1021. The first groove 1021 includes, but is not limited to, a circle, and can also be a square or other structures. At the same time, the depth of the first groove 1021 can be set according to the actual situation. For example, the first groove 1021 can completely accommodate the hydraulic top, or it can accommodate a part of the structure of the hydraulic top.

[0049] In the above implementation process, the first groove 1021 can be adapted to part of the structure of the hydraulic jack to limit the hydraulic jack, ensure the stability of the hydraulic jack between the outer end cover 101 and the inner end cover 102, and effectively suppress the expansion of the battery cell 50.

[0050] In some embodiments, the outer end cap 101 is provided with a second groove, and at least a portion of the structure of the hydraulic jack is disposed in the second groove. The second groove includes, but is not limited to, a circle, and may also be a square or other structures. The depth of the second groove can be set according to actual conditions. For example, the second groove may completely accommodate the hydraulic jack, or it may accommodate a portion of the structure of the hydraulic jack.

[0051] It should be noted that each of the hydraulic jacks can correspond to one of the first grooves 1021 and one of the second grooves, with one end of the hydraulic jack located in the first groove 1021 and the other end of the hydraulic jack located in the second groove.

[0052] In the above process, the second groove can be adapted to part of the structure of the hydraulic jack to limit the hydraulic jack, ensure the stability of the hydraulic jack between the outer end cover 101 and the inner end cover 102, and effectively suppress the expansion of the battery cell 50.

[0053] In some embodiments, the pre-tightening structure 20 further includes an oil pipe, the outer end cap 101 is provided with a mounting hole, one end of the oil pipe is connected to the hydraulic jack, and the other end passes through the mounting hole, wherein the oil pipe can be used to supply hydraulic oil to the hydraulic jack. This ensures a more compact overall structure of the battery module and improves space utilization.

[0054] like Figure 3 As shown, the battery module also includes an end plate 30, which is located on the side of the inner end cover 102 away from the outer end cover 101, and the end plate 30 is spaced apart from the inner end cover 102.

[0055] like Figures 1-2 As shown, the battery module also includes a surrounding plate assembly 40, which is connected to the outer end cover 101 and the end plate 30 respectively to enclose and form a receiving cavity.

[0056] For example, the enclosure assembly 40 includes a top cover 401, a bottom cover 402, and side plates 403. The top cover 401 is located at the upper end of the battery cell 50, the bottom cover 402 is located at the lower end of the battery cell 50, the side plates 403 are located on the left and right sides of the battery cell 50, the end plate 30 is located at the front end of the battery cell 50, and the outer end cover 101 and the inner end cover 102 are located at the rear end of the battery cell 50. The side plates 403 are fixed to the end plate 30 and the outer end cover 101 by laser welding, the top cover 401 is fixed to the end plate 30 and the outer end cover 101 by laser welding, and the bottom cover 402 is fixed to the end plate 30 and the outer end cover 101 by laser welding.

[0057] In some embodiments, the battery module further includes a battery cell 50 disposed in the receiving cavity.

[0058] A plurality of battery cells 50 are configured and distributed in the receiving cavity along a first direction, which includes but is not limited to the front-to-back direction. The positive and negative electrodes of the battery cells 50 can be located on the left and right sides, or possibly at the top. The battery cells 50 include, but are not limited to, solid-state batteries.

[0059] In some embodiments, the battery module further includes a CCS component 60 (Cells Contact System), which is connected to the battery cell 50 and is used to collect information from the battery cell 50.

[0060] For example, the CCS component 60 integrates information acquisition components (wire harness / PCB / FPC / FFC, etc.), plastic structural parts, aluminum busbars, and other components into a module, which is installed in the battery module to realize high-voltage series and parallel connection of battery cells 50206, temperature sampling of battery cells 50206, voltage sampling function, and overcurrent fuse, etc., and is part of the BMS battery management system.

[0061] It is understood that the positive and negative high voltage outputs and low voltage sampling of the CCS component 60 can be fixed to the outer end cover 101, and the other can be fixed to the end plate 30.

[0062] The battery module also includes a separator 70, which is disposed between two adjacent battery cells 50, and / or disposed on the outside of a plurality of battery cells 50. The separator 70 may be a fire-resistant material such as aerogel or mica, or it may be omitted. In the event of thermal runaway, it blocks the spread of heat, achieving fire prevention and other effects, thus improving the safety performance of the battery module.

[0063] The assembly process of the entire battery module is as follows:

[0064] The end plate 30 is fixed, the separator 70 and the battery cell 50 are stacked in a preset manner, the outer end cover 101, the pre-tightening structure 20 and the inner end cover 102 are combined together, the CCS assembly 60 is then welded, and finally the top cover 401, the bottom cover 402 and the side plate 403 are welded to complete the module assembly.

[0065] Secondly, this application also provides a battery pack, including the battery module as described above.

[0066] The battery module is configured with several modules, which are then connected in series, parallel, or mixed to form a whole and housed in a box to form the battery pack.

[0067] Since the battery pack provided in the second aspect includes the battery module, the battery pack has all the technical effects of the battery module, which will not be elaborated here.

[0068] Thirdly, this application also provides an electrical device including the battery pack described above.

[0069] Electrical equipment 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 equipment.

[0070] The vehicle has a battery pack installed inside, which can be located at the bottom, front, or rear of the vehicle. The battery pack can be used to power the vehicle; for example, it can serve as the vehicle's operating power source.

[0071] The vehicle may also include a controller and a motor, with the controller controlling the battery pack to power the motor, for example, for the vehicle's power needs during starting, navigation, and driving.

[0072] In some embodiments of this application, the battery pack can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0073] Since the electrical equipment provided by the third party includes a battery pack, the electrical equipment has all the technical effects of the battery pack, which will not be elaborated here.

[0074] In all embodiments of this application, "large" and "small" are relative terms, "more" and "less" are relative terms, and "upper" and "lower" are relative terms. The embodiments of this application will not elaborate further on the expression of such relative terms.

[0075] It should be understood that the phrases "in this embodiment," "in this application embodiment," or "as an optional implementation" throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, the phrases "in this embodiment," "in this application embodiment," or "as an optional implementation" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0076] In the various embodiments of this application, it should be understood that the sequence number of each process does not necessarily imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0077] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

Claims

1. A battery module, characterized by, include: An end cap assembly includes an outer end cap and an inner end cap, wherein the outer end cap and the inner end cap are spaced apart. A pre-tightening structure is provided between the outer end cap and the inner end cap to adjust the pre-tightening force on the inner end cap according to the pressure received by the inner end cap.

2. The battery module of claim 1, wherein, The pre-tightening structure includes a hydraulic jack, the output end of which contacts the outer end cap or the inner end cap.

3. The battery module of claim 2, wherein, The hydraulic jacks are provided in a plurality of manner, and the plurality of hydraulic jacks are spaced apart between the outer end cover and the inner end cover.

4. The battery module according to claim 2 or 3, characterized in that, The inner end cap is provided with a first groove, and at least a portion of the structure of the hydraulic jack is disposed in the first groove.

5. The battery module of claim 4, wherein, The outer end cap is provided with a second groove, and at least a portion of the structure of the hydraulic jack is disposed in the second groove.

6. The battery module of claim 2, wherein, The pre-tightening structure also includes an oil pipe, and the outer end cap is provided with a mounting hole. One end of the oil pipe is connected to the hydraulic jack, and the other end passes through the mounting hole.

7. The battery module of any one of claims 1 or 3, wherein, The battery module also includes an end plate, which is located on the side of the inner end cover away from the outer end cover, and the end plate is spaced apart from the inner end cover.

8. The battery module of claim 7, wherein, The battery module also includes a surrounding plate assembly, which is connected to the outer end cover and the end plate respectively to enclose and form a receiving cavity.

9. The battery module of claim 8, wherein, The battery module also includes individual battery cells, which are disposed in the receiving cavity.

10. The battery module of claim 9, wherein, The battery module also includes a CCS component, which is connected to the individual battery cells and is used to collect information from the individual battery cells.

11. A battery pack, characterized by Includes the battery module as described in any one of claims 1-10.

12. An electrical device, characterized by Includes the battery pack as described in claim 11.

Images