A battery module, a battery system, a battery pack, and a power utilization device

Abstract

The application relates to the battery technical field and provides a battery module, a battery system, a battery pack and a power utilization equipment. The battery module comprises a plurality of battery cells, a restraint structure and a compensation structure. The restraint structure is arranged around the periphery of the plurality of battery cells. The compensation structure comprises a circuit board and a piezoelectric element. The piezoelectric element is electrically connected to the circuit board and is located between the circuit board and the battery cells. The battery module of the application ensures that the restraint force of the battery cells is balanced in the whole life cycle and changes with the expansion force. The method is simple in structure and more intelligent, so that the use performance and the service life of the battery cells are improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery module, battery system, battery pack and electrical equipment. Background Technology

[0002] In recent years, with the rapid development and popularization of new energy vehicles, the application of batteries has become increasingly widespread. As the power source for automobiles and other electrical equipment, batteries play an irreplaceable role. High-expansion-force batteries, as a strategic product now and in the future, determine the performance of power batteries, and thus the upper limit of the entire vehicle.

[0003] However, during battery operation, due to various factors such as chemical reactions occurring inside the battery cell, the battery will generate an expansion force at the MPa level (far greater than that of conventional liquid batteries). If no restraining force is applied to constrain the deformation of the battery cell, it will lead to consequences such as battery cell bulging and cracking, rapid degradation of battery cell performance, and a sharp reduction in lifespan.

[0004] Current battery expansion force restraint schemes cannot guarantee that the cell surface is subjected to uniform and rated restraint, thus limiting battery performance. Utility Model Content

[0005] This application provides a battery module, battery system, battery pack, and electrical equipment that can guarantee the performance and lifespan of the battery module.

[0006] A first aspect of this application provides a battery module including a plurality of battery cells stacked along a first direction, a restraint structure, and a compensation structure. The restraint structure surrounds the outer periphery of the plurality of battery cells. The compensation structure includes a circuit board and a piezoelectric element. The piezoelectric element is electrically connected to the circuit board and is located between the circuit board and the battery cells.

[0007] The battery module of this application, by setting up a circuit board and piezoelectric components, provides wiring for the piezoelectric components and can connect to an external control module for transmitting electrical signals between the control module and the piezoelectric components. Additionally, the circuit board provides support for the battery cells. Specifically, when the battery cell expands, it applies pressure to the piezoelectric components, which generates an electrical signal. This signal is transmitted to the external control module via the circuit board. A larger signal indicates a greater expansion force of the battery cell, and a smaller signal indicates a smaller expansion force. Thus, the piezoelectric components can be used to detect the magnitude of the expansion force on the battery cell in real time. When the expansion force of the battery cell fluctuates, if the expansion force applied to the piezoelectric element decreases, according to the principle of action and reaction, the force exerted by the piezoelectric element on the battery cell also decreases. To ensure that the force exerted by the piezoelectric element on the battery cell meets the constraint force requirements, an electrical signal can be transmitted from the control module to the circuit board. The circuit board then transmits the signal to the piezoelectric element, causing it to deform towards the battery cell. This not only ensures that the piezoelectric element remains in contact with the battery cell but also compensates for insufficient constraint force provided by the constraint structure through deformation. The piezoelectric element replaces the constraint structure, applying sufficient constraint force to the battery cell and ensuring its performance. Furthermore, the constant contact between the piezoelectric element and the battery cell prevents the constraint structure from becoming inadequate in controlling the battery cell's expansion, thus better limiting its growth.

[0008] In one possible implementation, multiple piezoelectric elements are provided, with the multiple piezoelectric elements being arranged adjacently or spaced apart, or some of the piezoelectric elements being spaced apart and other piezoelectric elements being adjacent.

[0009] In one possible implementation, a plurality of the piezoelectric elements are arranged along the extension direction of the surface of the battery cell.

[0010] In one possible implementation, the piezoelectric elements are arranged in a matrix.

[0011] In one possible implementation, the piezoelectric element is a piezoelectric ceramic, quartz, or tourmaline.

[0012] In one possible implementation, the piezoelectric element abuts between the circuit board and the battery cell.

[0013] In one possible implementation, the circuit board is connected between the restraint structure and the plurality of battery cells.

[0014] In one possible implementation, the restraint structure includes a side plate, a first pull plate, and a second pull plate. Two side plates are provided, and the two side plates are respectively connected to both ends of the plurality of battery cells along the first direction. The first pull plate and the second pull plate are located at both ends of the plurality of battery cells along the second direction, which intersects with the first direction. Both ends of the first pull plate and the second pull plate are respectively connected to the two side plates, and the circuit board is connected to at least one of the side plates.

[0015] In one possible implementation, the circuit board has a through hole, and the side plate has a protrusion for insertion into the through hole.

[0016] In one possible implementation, the end face of the protrusion facing away from the side plate and the end face of the piezoelectric element facing away from the circuit board are flush.

[0017] In one possible implementation, a groove is also provided on the side plate, the protrusion is connected to the inner wall of the groove, and the circuit board is disposed in the groove.

[0018] In one possible implementation, the first pull plate and the second pull plate are connected to the side plate by welding, screwing, riveting or bonding.

[0019] In one possible implementation, the restraint structure further includes a buffer pad located between the piezoelectric element and the battery cell.

[0020] A second aspect of this application provides a battery system including a control module and the aforementioned battery module, wherein the control module is electrically connected to the circuit board.

[0021] A third aspect of this application provides a battery pack, including the battery module or battery system described above.

[0022] A fourth aspect of this application provides an electrical device, including an electrical appliance, the aforementioned battery module or the aforementioned battery system, or the aforementioned battery pack, wherein the battery module is used to provide electrical energy to the electrical appliance. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 Exploded views of a battery system provided according to some embodiments of this application are shown;

[0025] Figure 2 A cross-sectional view of a battery module provided according to some embodiments of this application is shown;

[0026] Figure 3 This paper shows a schematic diagram of the side plate and circuit board connection structure provided in some embodiments of this application;

[0027] Figure 4 A cross-sectional view is shown of the side panel and circuit board connection structure provided according to some embodiments of this application.

[0028] Figure label:

[0029] 10. Battery cell assembly; 11. Battery cell; 20. Restraint structure; 21. First pull plate; 22. Second pull plate; 23. Side plate; 231. Protrusion; 232. Sink; 24. Buffer pad; 30. Compensation structure; 31. Piezoelectric component; 32. Circuit board; 321. Through hole; 100. Battery module; 200. Control module. Detailed Implementation

[0030] This application provides a battery pack and an electrical device having the battery pack. The battery pack supplies power to the electrical device, which includes an electrical appliance and a battery capable of providing electrical energy to the appliance. In this application embodiment, the electrical device can be a vehicle. Based on the design of the battery pack in this application embodiment, the vehicle has stronger power performance and smoother power delivery. The vehicle can be a sedan, bus, or truck. For example, the vehicle can be an electric vehicle (EV), a pure electric vehicle / battery electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), a new energy vehicle, or any vehicle with a battery. The battery pack includes a housing and the aforementioned battery cells, with the battery cells located within the housing.

[0031] A battery pack consists of battery modules, connectors, a Battery Management System (BMS), a battery thermal management device, necessary structural supports, and structural protection structures. A battery module is formed by connecting multiple battery cells in series or parallel to a frame structure composed of multiple beams, along with auxiliary structural components that collect current, gather data, and secure and protect the cells. This assembly requires first connecting the required battery cells into a single unit before combining it with the frame structure; the resulting battery module is also a single, integrated structure. In this overall structure, the frame structure restrains the batteries, preventing them from expanding and causing deformation or cracking.

[0032] Currently, all battery expansion force restraint solutions are static restraints. Static restraints cannot guarantee uniform and rated restraint on the cell surface. For example, related technologies use the outer shell and buffer beams to provide pre-tightening force to suppress and absorb cell expansion; or, deformable tension plates and side plates are used to absorb deformation caused by cell expansion; or, air pressure is used to provide restraint force, ensuring uniform restraint force on all surfaces of the cell. All of these solutions are static restraint methods. The surfaces of the structures used to restrain the cell can become concave due to deformation, yielding, etc., thus reducing the restraint capacity of the concave areas. Furthermore, in the later stages of battery use, the cell expansion force fluctuates significantly, and the restraint structure is prone to non-rebound deformation due to cell expansion, causing the restraint structure to cease its restraining effect when the cell retracts. Therefore, the restraint structures in these technologies cannot provide dynamic restraint force based on the size of the cell expansion. Based on the characteristics of battery cells in practical applications, it can be seen that if the battery cell is squeezed and compressed by a restraint structure during operation, the performance of the battery cell can be fully utilized. If the battery cell is not restrained by the restraint structure during operation, the performance of the battery will be limited, resulting in poor performance and a decline in the performance of the entire battery module.

[0033] To address these issues, this application provides a battery module with a restraint structure for confining the battery cells. This structure prevents the cells from expanding and deforming during operation, thus protecting their lifespan. Furthermore, the restraint structure provides a restraining force to the working cells, allowing them to fully utilize their performance. The battery module also includes a compensation structure that provides a dynamic restraining force to the cells. This dynamic restraining force changes with the expansion of the cells, ensuring continuous restraint and guaranteeing their output performance.

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0035] Figure 1 Exploded views of a battery system provided according to some embodiments of this application are shown. Figure 2 A cross-sectional view of a battery module provided according to some embodiments of this application is shown. The X-axis represents a first direction parallel to the length direction of the battery module, the Y-axis represents a second direction parallel to the height direction of the battery module, and the Z-axis represents a third direction parallel to the width direction of the battery module.

[0036] This application provides a battery module and a battery system having the battery module, which are applied to battery packs or electrical devices. See also... Figure 1 and Figure 2 As shown, in some feasible implementations, the battery module 100 includes a battery cell 11, a restraint structure 20, and a compensation structure 30. The battery module 100 can include one or more battery cells 11. When multiple battery cells 11 are provided, they form a battery cell group 10, with the multiple battery cells 11 connected in series. This application uses a battery cell group 10 composed of multiple battery cells 11 as an example for illustration. When the battery module 100 includes multiple battery cells 11, the multiple battery cells 11 are arranged along a first direction. At this time, the length direction of the battery cell 11 is parallel to the width direction of the battery module 100, and the width direction of the battery cell 11 is parallel to the height direction of the battery module 100.

[0037] The restraint structure 20 is disposed around the outer periphery of the cell assembly 10. Part of the end face of the restraint structure 20 is used to fit against the surface of the cell 11. The restraint structure 20 is a closed-loop structure. In the free state, the restraint structure 20 can compress the cell 11, providing a restraining force to the cell 11. When the surface of the cell 11 expands, the surface of the cell 11 compresses the end face of the restraint structure 20, and the restraint structure 20 can also prevent the cell 11 from expanding and deforming.

[0038] The compensation structure 30 of this application includes a circuit board 32 and a piezoelectric element 31. In some embodiments, the circuit board 32 can be connected to the restraint structure 20, and the piezoelectric element 31 is electrically connected to the circuit board 32. The piezoelectric element 31 is located between the circuit board 32 and the battery cell 11, and the end face of the piezoelectric element 31 facing away from the circuit board 32 is just in contact with the end face of the battery cell 11 that should be in contact with the restraint structure 20.

[0039] The battery system of this application also includes a control module 200. The circuit board 32 is electrically connected to the control module 200. The control module 200 can be a control board such as a microcontroller. The control board has a receiving module, an output module, and a processing module. The receiving module receives the electrical signal generated after the piezoelectric element 31 is squeezed. The processing module determines whether it is necessary to provide an electric field force to the piezoelectric element 31 based on the magnitude of the electrical signal. The provided power is output to the piezoelectric element 31 by the output module to control the deformation of the piezoelectric element 31.

[0040] In the battery module 100 of this application, a compensation structure 30 is provided between the restraint structure 20 and the battery cell 11. The piezoelectric element 31 of the compensation structure 30 is a crystalline material that generates a voltage between its two end faces when subjected to pressure. When the piezoelectric material is subjected to an external force in a fixed direction, polarization occurs internally, and opposite charges are generated on two surfaces. When the external force is removed, the material returns to its uncharged state. When the direction of the external force changes, the polarity of the charge also changes. The amount of charge generated by the material under force is proportional to the magnitude of the external force; this phenomenon is called the direct piezoelectric effect. When an electric field is applied to the piezoelectric material, mechanical deformation occurs in certain directions of the material, and the amount of deformation is proportional to the strength of the external electric field; this phenomenon is called the inverse piezoelectric effect. In other words, the piezoelectric element 31 has the function of converting and inversely converting mechanical energy to electrical energy.

[0041] Under the expansion force of the battery cell 11, the surface of the restraint structure 20 is prone to indentation or deformation. The expansion force of the battery cell 11 has fluctuating characteristics. When the expansion force of the battery cell 11 is large, the degree of expansion of the battery cell 11 is large. The parts of the restraint structure 20 that have indentation or deformation can normally abut against the battery cell 11 to limit the continuous expansion of the battery cell 11 and apply a restraining force to the battery cell 11. However, when the expansion force of the battery cell 11 decreases and the volume of the battery cell 11 shrinks, the parts of the restraint structure 20 that have indentation or deformation cannot always adhere to the battery cell 11. Not only can it not provide a restraining force to the battery cell 11, but it will also reduce its ability to limit the expansion of the battery cell 11.

[0042] The battery module 100 of this application includes a circuit board 32 and a piezoelectric element 31. The circuit board 32 provides wiring for the piezoelectric element 31 and can be connected to an external control module 200 to transmit electrical signals between the control module 200 and the piezoelectric element 31. Additionally, the circuit board 32 provides support for the battery cell 11. Specifically, when the battery cell 11 expands, it applies pressure to the piezoelectric element 31. This pressure causes the piezoelectric element 31 to generate an electrical signal, which can be transmitted to the external control module 200 via the circuit board 32. A larger electrical signal indicates a greater expansion force of the battery cell 11, and a smaller electrical signal indicates a smaller expansion force. Thus, the piezoelectric element 31 can be used to detect the magnitude of the expansion force on the battery cell 11 in real time. When the expansion force of the battery cell 11 fluctuates, if the expansion force applied to the piezoelectric element 31 by the battery cell 11 decreases, according to the principle of action and reaction, the force exerted by the piezoelectric element 31 on the battery cell 11 also decreases. In order to ensure that the force of the piezoelectric element 31 on the battery cell 11 meets the restraint force requirements of the battery cell 11, an electrical signal can be transmitted from the control module 200 to the circuit board 32. The circuit board 32 transmits the electrical signal to the piezoelectric element 31, causing the piezoelectric element 31 to deform toward the battery cell 11. This not only ensures that the piezoelectric element 31 is always in contact with the battery cell 11, but also compensates for the insufficient restraint force provided by the restraint structure 20 through the deformation of the piezoelectric element 31. The piezoelectric element 31 replaces the restraint structure 20 to apply sufficient restraint force to the battery cell 11, ensuring the performance of the battery cell 11. In addition, the piezoelectric element 31 is always in contact with the cell 11, which can also prevent the cell 11 from being unable to expand due to the depression and deformation of the restraint structure 20, so as to better limit the expansion of the cell 11.

[0043] It is worth mentioning that, in some embodiments, the circuit board 32 can also be disposed between two adjacent battery cells 11, with the end face of the piezoelectric element 31 on the circuit board 32 away from the circuit board 32 attached to the surface of the battery cell 11. When the battery cell 11 expands, an expansion force can be applied to the piezoelectric element 31, at which time the piezoelectric element 31 can monitor the expansion force between two adjacent battery cells 11 in real time. When the expansion force of the battery cell 11 fluctuates, if the expansion force applied to the piezoelectric element 31 by the battery cell 11 decreases, according to the principle of action and reaction forces, the force exerted by the restraint structure 20 on the battery cell 11 also decreases. To ensure the required restraint force on the surface of the battery cell 11, an electrical signal can be transmitted from the control module 200 to the circuit board 32. The circuit board 32 then transmits the electrical signal to the piezoelectric element 31, causing the piezoelectric element 31 to deform toward the battery cell 11. This not only ensures that the piezoelectric element 31 is always in contact with the battery cell 11, but also causes the surfaces of two adjacent battery cells 11 to have a force generated by the deformation of the piezoelectric element 31. This makes the battery cell 11 tend to move toward the restraint structure 20, while the restraint structure 20 hinders the movement of the battery cell 11. In this way, the restraint structure 20 and the battery cell 11 generate a counterforce to compensate for the restraint force on the battery cell 11.

[0044] Therefore, the battery module 100 of this application can achieve dynamic restraint of the battery cell 11 by setting the compensation structure 30. It can monitor the expansion force of the battery cell 11 in real time and adjust the restraint force dynamically according to the expansion force fluctuation of the battery cell 11, so that the battery cell 11 is subjected to a uniform and rated restraint force, ensuring that the restraint force of the battery cell 11 is balanced throughout its entire life cycle and changes with the expansion force. The method is simple in structure and more intelligent, thereby improving the performance and life of the battery cell 11.

[0045] See Figure 1 and Figure 2 As shown, in some feasible implementations, one function of the piezoelectric element 31 in this application is to output an electrical signal of corresponding magnitude to the control module 200 based on the extrusion deformation. Another function is to generate a deformation of corresponding magnitude based on the magnitude of the electrical signal applied to the piezoelectric element 31 by the control module 200, thereby achieving detection and compensation. The piezoelectric element 31 in this application can be piezoelectric ceramic, quartz, or tourmaline. This application uses piezoelectric ceramic as an example for illustration. When the piezoelectric element 31 is piezoelectric ceramic, the strength of the piezoelectric ceramic must be greater than or equal to the strength of the restraint structure 20.

[0046] When dynamically restraining the battery cell 11, it is necessary to consider that the end face corresponding to the battery cell 11 can obtain dynamic restraint force. The end face corresponding to the battery cell 11 refers to the end face that originally needs to contact the restraint structure 20, and this end face is also the end face that expands when the battery cell 11 is working. Multiple piezoelectric elements 31 are arranged on the restraint structure 20 corresponding to the end face of the battery cell 11 that expands, and the piezoelectric elements 31 are arranged along the expansion end face of the battery cell 11.

[0047] It is worth mentioning that these piezoelectric elements 31 can be adjacent to each other, that is, the peripheral walls of two adjacent piezoelectric elements 31 can be tightly pressed together. This ensures that any two adjacent piezoelectric elements 31 are adjacent, which can improve the accuracy of the piezoelectric elements 31 in controlling the restraint force. Alternatively, some piezoelectric elements 31 can be adjacent, while others are spaced apart; or multiple piezoelectric elements 31 can be spaced apart. It is understandable that if the piezoelectric elements 31 in a certain part of the restraint structure 20 are adjacent, it indicates a higher density of piezoelectric elements 31. Spaced-apart piezoelectric elements 31 result in a lower density at that location in the restraint structure 20. Higher density leads to higher accuracy in controlling the restraint force of the compensation structure 30, but also increases the complexity and cost of the compensation structure 30. Lower density reduces the cost of the compensation structure 30. The arrangement of the piezoelectric elements 31 can be set according to the actual expansion of the battery cell 11. In this application, the example of multiple piezoelectric elements 31 being spaced apart is used for illustration.

[0048] It should be noted that when the piezoelectric elements 31 are spaced apart, the spacing between two adjacent piezoelectric elements 31 can be equal, partially equal, or the spacing between two adjacent piezoelectric elements 31 can gradually increase or decrease along the arrangement direction. In the embodiments of this application, multiple piezoelectric elements 31 are arranged in a matrix, and the spacing between two adjacent piezoelectric elements 31 is equal. By arranging the piezoelectric elements 31 in a matrix, the force on the piezoelectric elements 31 can be made more uniform, and a uniform restraint force can be provided.

[0049] In some feasible implementations, the number of piezoelectric elements 31 is not limited. Theoretically, the more piezoelectric elements 31, the better, as more piezoelectric elements 31 result in higher resolution, allowing for more precise monitoring of the expansion force of the battery cell 11 and more precise control of the restraint force. However, more piezoelectric elements 31 also increase the complexity of the entire compensation structure 30, the system required to control the piezoelectric elements 31, and the cost. Therefore, in this application, the number of piezoelectric elements 31 ranges from 1 to 1000. When there is only one piezoelectric element 31, it is a plate-like structure with its end face attached to the battery cell 11. Considering control accuracy and cost, a maximum of 1000 piezoelectric elements 31 are used. In practical applications, 100 piezoelectric elements 31 are used in this application.

[0050] In some feasible methods, when the restraint force is dynamically compensated by the compensation structure 30, a target value H of the restraint force needs to be set in the initial stage. This target value of the restraint force is the initial value that the restraint structure 20 needs to provide to the cell 11. When the cell 11 expands, the piezoelectric element 31 is squeezed and outputs a corresponding electrical signal to the control module 200 according to the magnitude of the force. The control module 200 processes the electrical signal. The processing steps are as follows: First, the actual expansion force F of each piezoelectric element 31 is calculated based on the electrical signal. Second, the force N = HF that needs to be compensated is calculated based on the actual expansion force F of each piezoelectric element 31. After the control module 200 calculates the compensation force N, it drives the current output to the corresponding piezoelectric element 31 according to the magnitude N of the compensation force of each piezoelectric element 31. Under the condition of current flow, the piezoelectric element 31 outputs the compensation force N, thereby completing the force compensation.

[0051] It should be noted that when compensating for the expansion force of the battery cell 11, the control module 200 can periodically collect the expansion force applied to the piezoelectric element 31 by the battery cell 11. In this embodiment, the period for the control module 200 to collect the expansion force of the battery cell 11 can be set to 5 minutes. Of course, this period can be changed according to actual needs and is not limited here. Dynamic force compensation throughout the entire life cycle of the battery pack can be achieved through the cyclical collection.

[0052] Figure 3 This diagram illustrates a structural schematic of the connection structure between the side plate 23 and the circuit board 32 according to some embodiments of this application. Figure 4A cross-sectional view is shown of the connection structure between the side plate 23 and the circuit board 32 provided in some embodiments of this application.

[0053] See Figure 1 , Figure 3 and Figure 4 As shown, in some feasible implementations, the restraint structure 20 includes a side plate 23, a first pull plate 21, and a second pull plate 22. The side plate 23, the first pull plate 21, and the second pull plate 22 are connected to form a closed-loop structure surrounding the outer periphery of the battery cell assembly 10. Two side plates 23 are provided, spaced apart, and the first pull plate 21 and the second pull plate 22 are also spaced apart. The first pull plate 21 and the second pull plate 22 are located between the two side plates 23. The two side plates 23 are respectively connected to both ends of a plurality of battery cells 11 along the first direction, and the first pull plate 21 and the second pull plate 22 are located at both ends of the plurality of battery cells 11 along the second direction. The two ends of the first pull plate 21 along the first direction are respectively connected to one end of the two side plates 23 along the second direction, and the two ends of the second pull plate 22 along the first direction are respectively connected to the other end of the two side plates 23 along the second direction. It is understood that the ends connecting the two side plates 23 and the first pull plate 21 are located on one side in the second direction, and the ends connecting the two side plates 23 and the second pull plate 22 are located on the other side in the second direction. In this way, the two side plates 23 can provide a restraining force for the cell 11 in the length direction of the battery module 100, and the first pull plate 21 and the second pull plate 22 can provide a restraining force for the cell 11 in the height direction of the battery module 100.

[0054] It should be noted that the connection methods between the first pull plate 21, the second pull plate 22 and the side plate 23 include, but are not limited to, welding, screwing, riveting or bonding.

[0055] In this embodiment, the compensation structure 30 can be disposed on the side plate 23 to compensate for the restraining force of the battery cell 11 in the length direction. In some other embodiments, the compensation structure 30 can also be disposed on the first pull plate 21 and the second pull plate 22, or the compensation structure 30 can also be disposed at both ends in the width direction of the battery module 100. The specific arrangement of the compensation structure 30 can be determined according to the actual situation.

[0056] In some feasible ways, the circuit board 32 is connected to the end of the side plate 23 facing the cell 11, and the end of the circuit board 32 facing away from the piezoelectric element 31 can be connected to the side plate 23 by adhesive bonding, welding or riveting.

[0057] In addition, a through hole 321 can be provided on the circuit board 32. The through hole 321 is located between the gaps of the piezoelectric elements 31. A protrusion 231 is provided on the side plate 23. The protrusion 231 can be inserted into the through hole 321. The shape and size of the protrusion 231 are the same as those of the through hole 321. This can ensure that the position of the circuit board 32 on the side plate 23 is stable and that the circuit board 32 is not prone to displacement. Moreover, the through hole 321 on the circuit board 32 can reduce the amount of material used in the circuit board 32, which not only facilitates the manufacturing of the circuit board 32 but also reduces the cost.

[0058] In this application, the end face of the protrusion 231 facing away from the side plate 23 and the end face of the piezoelectric element 31 facing away from the circuit board 32 are flush, so that both the protrusion 231 and the piezoelectric element 31 can abut against the battery cell 11.

[0059] For example, the end face of the piezoelectric element 31 facing away from the circuit board 32 may also protrude from the end face of the protrusion 231 facing away from the side plate 23, in which case the piezoelectric element 31 abuts against the battery cell 11.

[0060] It is worth mentioning that a recessed groove 232 is also provided on the side plate 23. The shape and size of the recessed groove 232 are the same as those of the circuit board 32, so that the circuit board 32 can be fitted into the recessed groove 232. The protrusion 231 is located in the recessed groove 232 and is connected to the inner wall of the recessed groove 232.

[0061] When connecting circuit board 32 and side plate 23, circuit board 32 can be placed in recess 232. The wall of recess 232 can connect with circuit board 32, thus increasing the connection area between circuit board 32 and side plate 23 and increasing the connection strength. Recess 232 can restrict the position of circuit board 32, making the connection position between circuit board 32 and side plate 23 more precise. Moreover, the inner wall of recess 232 has a restrictive effect on circuit board 32. When cell 11 squeezes piezoelectric element 31, circuit board 32 is also subjected to squeezing. Recess 232 can limit the deformation of circuit board 32 when squeezed, enhancing the squeezing resistance of circuit board 32.

[0062] In this embodiment, the restraint structure 20 further includes a buffer pad 24, which is located between the piezoelectric element 31 and the battery cell 11. The buffer pad 24 is a flexible foam-like pad with uniform thickness. The specific thickness of the buffer pad 24 is not limited but is determined based on the specific material properties of the buffer pad 24 and the expansion force of the battery cell 11. By providing the buffer pad 24, the compressive force exerted on the piezoelectric element 31 by the expansion of the battery cell 11 can be uniformly transmitted to the piezoelectric element 31, and the compressive force of the piezoelectric element 31 can also be uniformly transmitted to the battery cell 11. Furthermore, the buffer pad 24 can effectively suppress and absorb the expansion of the battery cell 11, avoiding excessive compression.

[0063] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0064] In the description of this utility model, it should be understood that the terms "comprising" and "having" and any variations thereof used in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0065] Unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A battery module, characterized in that, include: Multiple battery cells (11) stacked along a first direction; A restraint structure (20) is disposed around the outer periphery of the plurality of battery cells (11); as well as The compensation structure (30) includes a circuit board (32) and a piezoelectric element (31), the piezoelectric element (31) being electrically connected to the circuit board (32) and located between the circuit board (32) and the battery cell (11).

2. The battery module according to claim 1, characterized in that, Multiple piezoelectric elements (31) are provided, and the multiple piezoelectric elements (31) are arranged adjacently or spaced apart, or some of the piezoelectric elements (31) are spaced apart and other piezoelectric elements (31) are adjacent.

3. The battery module according to claim 2, characterized in that, Multiple piezoelectric elements (31) are arranged along the extension direction of the surface of the cell (11).

4. The battery module according to claim 3, characterized in that, The piezoelectric elements (31) are arranged in a matrix.

5. The battery module according to claim 1, characterized in that, The piezoelectric element (31) is a piezoelectric ceramic, quartz or tourmaline.

6. The battery module according to claim 1, characterized in that, The piezoelectric element (31) abuts between the circuit board (32) and the battery cell (11).

7. The battery module according to any one of claims 1-6, characterized in that, The circuit board (32) is connected between the restraint structure (20) and the plurality of battery cells (11).

8. The battery module according to claim 7, characterized in that, The restraint structure (20) includes a side plate (23), a first pull plate (21), and a second pull plate (22). There are two side plates (23), which are respectively connected to the two ends of the plurality of battery cells (11) along the first direction. The first pull plate (21) and the second pull plate (22) are located at the two ends of the plurality of battery cells (11) along the second direction, which intersects with the first direction. The two ends of the first pull plate (21) and the second pull plate (22) are respectively connected to the two side plates (23). The circuit board (32) is connected to at least one of the side plates (23).

9. The battery module according to claim 8, characterized in that, The circuit board (32) has a through hole (3100), and the side plate (23) has a protrusion (231) for insertion into the through hole (3100).

10. The battery module according to claim 9, characterized in that, The end face of the protrusion (231) facing away from the side plate (23) is flush with the end face of the piezoelectric element (31) facing away from the circuit board (32).

11. The battery module according to claim 9, characterized in that, The side plate (23) is also provided with a recessed groove (232), the protrusion (231) is connected to the inner wall of the recessed groove (232), and the circuit board (32) is disposed in the recessed groove (232).

12. The battery module according to claim 8, characterized in that, The first pull plate (21) and the second pull plate (22) are connected to the side plate (23) by welding, screwing, riveting or bonding.

13. The battery module according to any one of claims 1-6, characterized in that, The restraint structure (20) also includes a buffer pad (24) located between the piezoelectric element (31) and the battery cell (11).

14. A battery system, characterized in that, It includes a control module and a battery module (100) as described in any one of claims 1-12, wherein the control module is electrically connected to the circuit board (32).

15. A battery pack, characterized in that, This includes the battery module (100) as described in any one of claims 1-13, or the battery system as described in claim 14.

16. An electrical appliance, characterized in that, The device includes an electrical appliance, a battery module (100) according to any one of claims 1-13, or a battery system according to claim 14, or a battery pack according to claim 15, wherein the battery module is used to provide electrical energy to the electrical appliance.

Images