Battery pack and electric device

Abstract

The application provides a battery pack and an electric device, and belongs to the technical field of batteries. The battery pack comprises a shell, a battery cell module and a structural member. At least part of the battery cell module is accommodated in the shell, and the battery cell module comprises a plurality of battery cells arranged in a stack along a first direction. The structural member is arranged along the first direction with the battery cell module. The structural member comprises a plurality of side walls arranged in sequence along the first direction with the battery cell module, and a connecting portion is connected between each adjacent two side walls. The bending modulus of each connecting portion is smaller than that of the two side walls connected with the connecting portion. The plurality of side walls comprise a first side wall and a second side wall, the first side wall is fixedly connected with the shell, and the second side wall is connected with the battery cell module. The battery pack can provide an expansion space for the battery cells through the structural member, and can also constrain the expansion of the battery cells, thereby being beneficial to improving the use safety and service life of the battery pack.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery pack and a power utilization device. BACKGROUND

[0002] In recent years, secondary batteries have developed rapidly. With the increasing application of secondary batteries in various fields, secondary batteries are facing higher requirements in terms of use safety and service life. A battery pack of a secondary battery has multiple battery cells. A battery cell is assembled into an electrode assembly (bare battery cell) by winding or stacking a positive electrode sheet, a negative electrode sheet and a separator, and then is loaded into a shell, and finally is obtained by injecting electrolyte. The battery cells of the battery pack in the prior art will swell after long-term use, which is not conducive to the use safety and service life of the battery pack. SUMMARY

[0003] The embodiments of the present application provide a battery pack and a power utilization device, which are conducive to improving the use safety and service life of the battery pack.

[0004] In a first aspect, the embodiments of the present application provide a battery pack, which comprises a shell, a battery cell module and a structural member. At least part of the battery cell module is accommodated in the shell. The battery cell module comprises multiple battery cells, and the multiple battery cells are arranged in a stack along a first direction. The structural member is arranged along the first direction with the battery cell module. The structural member comprises multiple side walls, which are arranged along the first direction with the battery cell module in sequence. A connecting portion is connected between each adjacent two side walls. The bending modulus of each connecting portion is less than the bending modulus of the two side walls connected with the connecting portion. The multiple side walls comprise a first side wall and a second side wall. The first side wall is connected with the shell, and the second side wall is connected with the battery cell module.

[0005] In the above technical solution, the structure member is arranged in the battery pack, the structure member and the battery cell module are arranged along the first direction, the structure member is provided with a plurality of side walls, the first side wall and the second side wall of the plurality of side walls are connected with the shell and the battery cell module respectively, that is, the first side wall and the second side wall are located at two ends of the structure member in the first direction, a connecting portion is arranged between each adjacent two side walls, and the bending modulus of the connecting portion is less than that of the two side walls connected therewith, so that the anti-deformation ability of the connecting portion is less than that of the corresponding side wall, so that the connecting portion of the structure member deforms and collapses when the battery cell of the battery cell module expands along the first direction, and pressure along the first direction is provided to the battery cell module, so that the structure member not only provides a certain expansion space for the battery cell, but also restrains the expansion of the battery cell to a certain extent, which is helpful to compensate for the displacement deviation of the battery cell after expansion, reduce the phenomenon that the battery cell is damaged due to excessive expansion in use, and reduce the risk of sudden increase of internal pressure of the battery cell due to inability to expand, thereby improving the service life and safety of the battery pack. In addition, by arranging the collapsible structure member between the battery cell module and the shell, the expansion space and pressure requirement of the battery cell of the battery cell module are provided, which is helpful to reduce the use of foam between the battery cells, thereby on the one hand, it is helpful to save the production materials required by the battery pack, thereby reducing the production cost of the battery pack, and it is helpful to reduce the assembly difficulty of the battery pack, thereby optimizing the production rhythm of the battery pack, and on the other hand, the assembly tightness between the battery cells is higher, which is helpful to improve the energy density of the battery pack.

[0006] In some embodiments, the bending modulus of the shell is greater than the bending modulus of the side wall.

[0007] In the above technical solution, by setting the bending modulus of the shell to be greater than the bending modulus of the side wall, the anti-deformation ability of the shell is stronger than that of the structure member, so as to reduce the deformation of the shell in use, and the shell is helpful to improve the better stability and support effect of the structure member.

[0008] In some embodiments, the bending modulus of the first side wall is greater than the bending modulus of the second side wall.

[0009] In the above technical solution, by setting the bending modulus of the first side wall to be greater than the bending modulus of the second side wall, the anti-deformation ability of the first side wall is stronger than that of the second side wall, so as to make the first side wall connected to the shell improve the better stability and support effect of the structure member, which is helpful to reduce the phenomenon that the structure member cannot provide pressure along the first direction to the battery cell module due to the deformation of the first side wall, and is helpful to improve the pressure effect of the structure member on the battery cell module.

[0010] In some embodiments, along the first direction, the distance between the first side wall and the second side wall is greater than or equal to 10% of the length of the battery cell module.

[0011] In the technical solution, the distance between the first side wall and the second side wall is greater than or equal to 10% of the size of the battery cell module in the first direction, so that the distance between the first side wall and the second side wall in the first direction is greater than the maximum expansion amount of the battery cell module in the first direction, and the structural member provides sufficient expansion space for the battery cell module when it collapses and deforms in the first direction, thereby reducing the use safety hazards caused by insufficient expansion space of the battery cell.

[0012] In some embodiments, the number of side walls is at least three, and other side walls are located between the first side wall and the second side wall. The bending modulus of the first side wall is greater than that of the other side walls, and the bending modulus of the second side wall is greater than that of the other side walls.

[0013] In the technical solution, the bending modulus of the first side wall and the bending modulus of the second side wall of the structural member are both greater than the bending modulus of the other side walls of the structural member, and the other side walls are located between the first side wall and the second side wall. The anti-deformation ability of the first side wall and the second side wall located at both ends of the structural member in the first direction is greater than that of the side walls located between the first side wall and the second side wall, so that the side walls located between the first side wall and the second side wall deform preferentially, thereby alleviating the deformation of the first side wall and the second side wall during use, and further improving the connection reliability between the first side wall and the shell and the connection reliability between the second side wall and the battery cell module.

[0014] In some embodiments, the plurality of side walls further includes a third side wall, and the distance between the first side wall and the third side wall in the first direction is less than the distance between the third side wall and the second side wall.

[0015] In the technical solution, a third side wall is provided between the first side wall and the second side wall to facilitate manufacturing and improve the overall structural stability of the structural member, thereby alleviating the phenomenon of side displacement deformation of the structural member in a direction perpendicular to the first direction during collapse and deformation in the first direction. In addition, by setting the distance between the first side wall and the third side wall to be less than the distance between the third side wall and the second side wall, the area of the structural member between the third side wall and the second side wall is more prone to collapse and deformation in the first direction, thereby alleviating the impact of the structural member on the first side wall during collapse and deformation, and further improving the stability of the first side wall connected to the shell and the supporting effect of the first side wall on other side walls.

[0016] In some embodiments, the distance between the second side wall and the third side wall in the first direction is greater than or equal to 10% of the length of the battery cell module.

[0017] In the technical solution, the distance between the second side wall and the third side wall is greater than or equal to 10% of the size of the battery cell module in the first direction, so that the size of the region where the structural member is more likely to deform is greater than the maximum expansion amount of the battery cell module in the first direction, the structural member provides sufficient expansion space for the battery cell module when collapsing and deforming in the first direction, and the use safety hazard caused by insufficient expansion space of the battery cell is reduced.

[0018] In some embodiments, the plurality of side walls further comprises a fourth side wall, and the distance between the third side wall and the fourth side wall in the first direction is greater than the distance between the first side wall and the third side wall; and / or, the distance between the third side wall and the fourth side wall in the first direction is greater than the distance between the fourth side wall and the second side wall.

[0019] In the technical solution, the fourth side wall is arranged between the third side wall and the second side wall, which is convenient for manufacturing and further improves the overall structural stability of the structural member, which is beneficial to alleviate the phenomenon of side displacement deformation of the structural member in the direction perpendicular to the first direction during the collapsing deformation in the first direction. In addition, the distance between the third side wall and the fourth side wall is greater than the distance between the first side wall and the third side wall, so that the region of the structural member between the third side wall and the fourth side wall is more likely to collapse and deform in the first direction, which alleviates the impact of the structural member on the first side wall during the collapsing deformation, thereby benefiting the stability of the first side wall connected to the shell and improving the supporting effect of the first side wall on other side walls. Similarly, the distance between the third side wall and the fourth side wall is greater than the distance between the fourth side wall and the second side wall, so that the region of the structural member that is more likely to collapse and deform is away from the second side wall, which is beneficial to reduce the impact of the structural member on the second side wall during the collapsing deformation, thereby benefiting the reliability of the connection between the second side wall and the battery cell module.

[0020] In some embodiments, the distance between the third side wall and the fourth side wall in the first direction is greater than or equal to 10% of the length of the battery cell module.

[0021] In the technical solution, the distance between the third side wall and the fourth side wall is greater than or equal to 10% of the size of the battery cell module in the first direction, so that the size of the region where the structural member is more likely to deform is greater than the maximum expansion amount of the battery cell module in the first direction, the structural member provides sufficient expansion space for the battery cell module when collapsing and deforming in the first direction, and the use safety hazard caused by insufficient expansion space of the battery cell is reduced.

[0022] In some embodiments, the plurality of side walls further comprises a fifth side wall, the fifth side wall is located between the third side wall and the fourth side wall along the first direction, a distance between the third side wall and the fifth side wall is greater than a distance between the first side wall and the third side wall; and / or, a distance between the third side wall and the fifth side wall is greater than a distance between the fourth side wall and the second side wall along the first direction.

[0023] In the above technical solution, by arranging the fifth side wall between the third side wall and the fourth side wall, the manufacturing is facilitated, and the overall structural stability of the structural member is further improved, and the phenomenon that the structural member is laterally deformed in a direction perpendicular to the first direction during the collapse deformation along the first direction is alleviated. In addition, by setting the distance between the third side wall and the fifth side wall to be greater than the distance between the first side wall and the third side wall, the region of the structural member between the third side wall and the fifth side wall is more prone to collapse deformation along the first direction, thereby alleviating the impact of the structural member on the first side wall during the collapse deformation, and further improving the stability of the first side wall connected to the shell, and improving the supporting effect of the first side wall on other side walls. Similarly, by setting the distance between the third side wall and the fifth side wall to be greater than the distance between the fourth side wall and the second side wall, the region of the structural member that is more prone to collapse deformation is away from the second side wall, which is conducive to reducing the impact of the structural member on the second side wall during the collapse deformation, thereby improving the reliability of the mutual connection between the second side wall and the battery cell module.

[0024] In some embodiments, a distance between the fourth side wall and the fifth side wall is greater than a distance between the first side wall and the third side wall along the first direction; and / or, a distance between the fourth side wall and the fifth side wall is greater than a distance between the fourth side wall and the second side wall along the first direction.

[0025] In the above technical solution, by setting the distance between the fourth side wall and the fifth side wall to be greater than the distance between the first side wall and the third side wall, the region of the structural member between the fourth side wall and the fifth side wall is more prone to collapse deformation along the first direction, thereby alleviating the impact of the structural member on the first side wall during the collapse deformation, and further improving the stability of the first side wall connected to the shell, and improving the supporting effect of the first side wall on other side walls. Similarly, by setting the distance between the fourth side wall and the fifth side wall to be greater than the distance between the fourth side wall and the second side wall, the region of the structural member that is more prone to collapse deformation is away from the second side wall, which is conducive to reducing the impact of the structural member on the second side wall during the collapse deformation, thereby improving the reliability of the mutual connection between the second side wall and the battery cell module.

[0026] In a second aspect, the embodiments of the present application further provide a power utilization device comprising the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope.

[0028] Figure 1 A structural schematic diagram of the battery pack provided by some embodiments of the present application;

[0029] Figure 2 An exploded view of the battery pack provided by some embodiments of the present application;

[0030] Figure 3 A top view of the battery pack (after removing the cover plate) provided by some embodiments of the present application;

[0031] Figure 4 A structural schematic diagram of the structural member provided by some embodiments of the present application;

[0032] Figure 5 A front view of the structural member provided by some embodiments of the present application;

[0033] Figure 6 A structural schematic diagram of the battery pack provided by some other embodiments of the present application;

[0034] Figure 7 An exploded view of the battery pack provided by some other embodiments of the present application;

[0035] Figure 8 An assembly schematic diagram of the battery cell module and the structural member provided by some embodiments of the present application;

[0036] Figure 9 An assembly schematic diagram of the battery cell module and the structural member in other embodiments provided by some embodiments of the present application;

[0037] Figure 10 An assembly schematic diagram of the battery cell module and the structural member in other embodiments provided by some embodiments of the present application;

[0038] Figure 11 A front view of the structural member provided by some other embodiments of the present application;

[0039] Figure 12 A structural schematic diagram of the structural member provided by some other embodiments of the present application;

[0040] Figure 13 A structural schematic diagram of the structural member provided by some other embodiments of the present application;

[0041] Figure 14 An assembly view of a structural member and a battery cell module is provided for some embodiments of the present application.

[0042] Figure 15 A front view of a structural member is provided for further embodiments of the present application.

[0043] Figure 16 A front view of a structural member is provided for further embodiments of the present application.

[0044] Figure 17 An assembly view of a power consuming device is provided for some embodiments of the present application.

[0045] Figure: 1000 - power consuming device; 100 - battery pack; 10 - housing; 11 - side plate; 20 - battery cell module; 21 - battery cell; 30 - structural member; 31 - side wall; 311 - first side wall; 312 - second side wall; 313 - third side wall; 314 - fourth side wall; 315 - fifth side wall; 32 - connecting part; 40 - cover plate; 50 - insulating member; X - first direction; Y - second direction; Z - third direction. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application; the use of the terms "include," "have" and the like are meant to encompass the items listed thereafter, and equivalents thereof as well as additional items. The use of the terms "first," "second" and the like in the specification are used for distinguishing between similar entities but do not necessarily indicate a particular order or a particular numbering of the entities.

[0048] Reference herein to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments.

[0049] In the description of the application, it should be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "attachment" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0050] The term "and / or" in the present application is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents that the front and rear associated objects have an "or" relationship.

[0051] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the present application.

[0052] "Multiple" appearing in the present application means more than two (including two).

[0053] In the present application, the battery cell can be a lithium ion battery, a lithium-sulfur battery, a sodium ion battery or a magnesium ion battery, etc. The present application embodiments are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc. The present application embodiments are not limited thereto. The battery cell is generally divided into three types according to the packaging method: cylindrical battery cell, square battery cell and soft package battery cell, and the present application embodiments are not limited thereto.

[0054] The battery pack mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. The battery pack generally includes a housing for packaging one or more battery cells. The housing can avoid the influence of liquid or other foreign matters on the charging or discharging of the battery cell.

[0055] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode tab and the negative electrode tab to work. The positive electrode tab includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the part of the positive electrode current collector without the positive electrode active material layer serves as a positive electrode tab to realize the input or output of electric energy of the positive electrode tab through the positive electrode tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode tab includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, and the part of the negative electrode current collector without the negative electrode active material layer serves as a negative electrode tab to realize the input or output of electric energy of the negative electrode tab through the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. In order to pass a large current without fusing, the number of positive electrode tabs can be multiple and stacked together, and the number of negative electrode tabs can also be multiple and stacked together.

[0056] The material of the separator can be PP (polypropylene) or PE (polyethylene) or the like. In addition, the electrode assembly can be a winding type structure or a stacking type structure, and the embodiments of the present application are not limited thereto.

[0057] The battery pack has the outstanding advantages of high energy density, small environmental pollution, large power density, long service life, wide application range, and small self-discharge coefficient, etc., and is an important part of the development of new energy today. The battery cell in the battery pack is assembled into an electrode assembly (bare battery cell) by winding or stacking the positive electrode tab, the negative electrode tab, and the separator, then is put into a shell, and finally is obtained after injecting the electrolyte. However, with the continuous development of battery technology, higher requirements for the use safety and service life of the battery pack are also put forward. Therefore, the use safety and service life of the battery cell determine the safety performance and service life of the battery pack.

[0058] The inventor found that for a general battery pack, the battery pack is usually provided with a shell and a battery cell module accommodated in the shell, the battery cell module includes a plurality of battery cells, and the plurality of battery cells are stacked in the shell in an array form. However, the battery cells will swell during the cyclic charging and discharging process. When the swelling of the battery cells is constrained, the internal pressure of the battery cells will suddenly increase, which will damage the performance of the battery cells. When the swelling of the battery cells is not constrained, the battery cells will swell too much, which will cause the risk of rupture and damage of the battery cells, and is not conducive to the use safety and service life of the battery pack.

[0059] In order to improve the use safety and service life of the battery pack, in the prior art, the foam is usually arranged between two adjacent battery cells in the stacking direction of the battery cells, on the one hand, the foam provides a certain expansion space for the battery cells, on the other hand, the foam exerts a certain pressure on the battery cells to constrain the expansion of the battery cells. However, in the battery pack with such a structure, the foam needs to be arranged between every two adjacent battery cells, on the one hand, the battery pack needs more foam, which is not conducive to reducing the production cost of the battery pack, on the other hand, the processing process of the battery pack is more complicated and the assembly is more difficult, which is not conducive to optimizing the production rhythm of the battery pack.

[0060] Based on the above considerations, in order to solve the problems of high production cost and difficult assembly of the battery pack, the inventors have designed a battery pack after deep research, which comprises a shell, a battery cell module and a structural member. At least part of the battery cell module is accommodated in the shell, the battery cell module comprises a plurality of battery cells, and the plurality of battery cells are arranged in a stacking manner along a first direction. The structural member is arranged along the first direction with the battery cell module. The structural member comprises a plurality of side walls, the plurality of side walls are arranged in sequence along the first direction with the battery cell module, a connecting portion is connected between every two adjacent side walls, the bending modulus of each connecting portion is less than the bending modulus of the two side walls connected with the connecting portion, the plurality of side walls comprise a first side wall and a second side wall, the first side wall is connected with the shell, and the second side wall is connected with the battery cell module.

[0061] In the battery pack with such a structure, the structural member is arranged along the first direction with the battery cell module, the structural member is provided with a plurality of side walls, the first side wall and the second side wall in the plurality of side walls are connected with the shell and the battery cell module respectively, by arranging a connecting portion between every two adjacent side walls and the bending modulus of the connecting portion being less than the bending modulus of the two side walls connected with the connecting portion, the anti-deformation ability of the connecting portion is less than the anti-deformation ability of the corresponding side wall, so that when the battery cells of the battery cell module expand along the first direction, the connecting portion of the structural member deforms and collapses to provide pressure on the battery cell module along the first direction, so that the structural member not only provides a certain expansion space for the battery cells, but also restrains the expansion of the battery cells to some extent, which is conducive to compensating for the displacement deviation of the battery cells after expansion, thereby reducing the phenomenon that the battery cells are damaged due to excessive expansion in the use process, and reducing the risk of sudden increase of internal pressure of the battery cells due to the inability to expand, thereby improving the service life and use safety of the battery pack. In addition, by arranging the collapsible structural member between the battery cell module and the shell to meet the expansion and pressure requirements of the battery cells of the battery cell module, the use of foam between the battery cells is reduced, thereby on the one hand, the production materials required by the battery pack are saved to reduce the production cost of the battery pack, and on the other hand, the assembly difficulty of the battery pack is reduced to optimize the production rhythm of the battery pack, and on the other hand, the assembly tightness between the battery cells is higher, which is conducive to improving the energy density of the battery pack.

[0062] The battery pack disclosed by the embodiments of the present application can be used in, but is not limited to, electric two-wheel vehicles, electric tools, unmanned aerial vehicles, energy storage devices and the like. The power supply system of the electric device can be composed of the battery pack disclosed by the present application, so that the production cost of the battery pack is reduced, and the assembly difficulty of the battery pack is reduced, so as to optimize the production rhythm of the battery pack.

[0063] The embodiments of the present application provide an electric device using a battery pack as a power supply. The electric device can be, but is not limited to, an electronic device, an electric tool, an electric two-wheel vehicle, an unmanned aerial vehicle, and an energy storage device. The electronic device can include a mobile phone, a tablet, a notebook computer, and the like. The electric tool can include a power drill, a power saw, and the like.

[0064] According to some embodiments of the present application, referring to Figures 1-5 , Figure 1 a structural schematic diagram of the battery pack 100 provided by some embodiments of the present application, Figure 2 an exploded view of the battery pack 100 provided by some embodiments of the present application, Figure 3 a top view of the battery pack 100 (after removing the cover plate 40) provided by some embodiments of the present application, Figure 4 a structural schematic diagram of the structural member 30 provided by some embodiments of the present application, Figure 5 a front view of the structural member 30 provided by some embodiments of the present application. The embodiments of the present application provide a battery pack 100, which includes a shell 10, a battery cell module 20, and a structural member 30. At least part of the battery cell module 20 is accommodated in the shell 10, and the battery cell module 20 includes a plurality of battery cells 21 stacked along a first direction X. The structural member 30 is arranged along the first direction X with the battery cell module 20. The structural member 30 includes a plurality of side walls 31 arranged along the first direction X with the battery cell module 20 in sequence, and a connecting portion 32 is connected between each adjacent two side walls 31. The bending modulus of each connecting portion 32 is less than the bending modulus of the two side walls 31 connected with the connecting portion 32. The plurality of side walls 31 includes a first side wall 311 and a second side wall 312, the first side wall 311 is connected with the shell 10, and the second side wall 312 is connected with the battery cell module 20.

[0065] The structural member 30 is accommodated in the shell 10, and the structural member 30 and the battery cell module 20 are arranged along the first direction X. The structural member 30 is provided with a plurality of side walls 31. The first side wall 311 and the second side wall 312 of the plurality of side walls 31 are connected to the shell 10 and the battery cell module 20, respectively. The first side wall 311 and the second side wall 312 are located at two ends of the structural member 30 in the first direction X. A connecting portion 32 is arranged between each adjacent two side walls 31. The bending modulus of the connecting portion 32 is less than the bending modulus of the two side walls 31 connected thereto. The anti-deformation ability of the connecting portion 32 is less than the anti-deformation ability of the corresponding side wall 31. When the battery cell 21 of the battery cell module 20 expands along the first direction X, the connecting portion 32 of the structural member 30 deforms and collapses, thereby providing pressure to the battery cell module 20 along the first direction X. The structural member 30 not only provides a certain expansion space for the battery cell 21, but also restricts the expansion of the battery cell 21 to some extent, effectively compensates for the displacement deviation of the battery cell 21 after expansion, thereby reducing the phenomenon that the battery cell 21 is damaged due to excessive expansion during use, and reducing the risk of sudden increase of internal pressure of the battery cell 21 due to the inability to expand, thereby improving the service life and safety of the battery pack 100. In addition, by arranging the collapsible structural member 30 between the battery cell module 20 and the shell 10, the expansion and pressure requirements of the battery cell 21 of the battery cell module 20 are met, thereby reducing the use of foam between the battery cells 21, thereby on the one hand, it is beneficial to save the production materials required by the battery pack 100, thereby reducing the production cost of the battery pack 100, and it is beneficial to reduce the assembly difficulty of the battery pack 100, thereby optimizing the production rhythm of the battery pack 100, on the other hand, the assembly tightness between the battery cells 21 is higher, which is beneficial to improve the energy density of the battery pack 100.

[0066] The shell 10 is used to provide an assembly space for the battery cell module 20. The shell 10 can adopt various structures, such as a rectangular structure, a cylindrical structure, etc. For example, in the embodiment, the shell 10 is a rectangular structure. Figure 2 The shell 10 is a rectangular structure.

[0067] Optionally, the battery pack 100 can further include a cover plate 40, which is covered with the shell 10. The cover plate 40 and the shell 10 jointly define an assembly space for accommodating the battery cell module 20.

[0068] For example, in the embodiment, the cover plate 40 is a rectangular structure. Figure 2In the embodiment shown in FIG. 1, the shell 10 is a hollow structure with one end open to form a receiving cavity for accommodating the battery cell module 20, and the cover plate 40 is a plate-shaped structure that covers the open end of the shell 10 to jointly define an assembly space with the shell 10, and the battery cell module 20 is entirely accommodated in the shell 10. Of course, in other embodiments, the battery cell module 20 can be partially accommodated in the shell 10. For example, the cover plate 40 and the shell 10 are both hollow structures with one side open, and the open end of the cover plate 40 covers the open end of the shell 10 to achieve partial accommodation of the battery cell module 20 in the shell 10 and partial accommodation of the battery cell module 20 in the cover plate 40.

[0069] In the embodiment shown in FIG. 1, the shell 10 has two side plates 11 arranged opposite to each other in the first direction X, the plurality of battery cells 21 of the battery cell module 20 are stacked between the two side plates 11 in the first direction X, the structural member 30 is arranged between the side plates 11 and the battery cell module 20 in the first direction X, and the structural member 30 is connected to the side plates 11.

[0070] It should be noted that the structure of the battery pack 100 can also be various. For example, referring to FIGS. 2 and 3, Figure 6 and Figure 7 shown in FIGS. 4 and 5, Figure 6 are structural diagrams of the battery pack 100 provided by some embodiments of the present application, Figure 7 are exploded structural diagrams of the battery pack 100 provided by some embodiments of the present application. The shell 10 has only one side plate 11 in the first direction X, and the structural member 30 is arranged on the side of the battery cell module 20 away from the side plate 11 in the first direction X, and the two ends of the first side wall 311 in the second direction Y are connected to the shell 10, so that the structural member 30 is connected to the shell 10, and the structural member 30 and the shell 10 jointly define an assembly space for accommodating the battery cell module 20. The battery pack 100 with this structure is convenient for users to observe when the structural member 30 is abnormally used, so as to facilitate the maintenance of the battery pack 100. In other embodiments, the shell 10 of the battery pack 100 can also not have side plates 11 on both sides in the first direction X, i.e., the shell 10 is open on both sides in the first direction X. In this embodiment, the structural member 30 can be arranged on both sides of the battery cell module 20 in the first direction X, so that the two structural members 30 and the shell 10 jointly define an assembly space for accommodating the battery cell module 20.

[0071] In the battery cell module 20, the plurality of battery cells 21 can be connected in series, in parallel, or in a mixed manner. The mixed connection means that some of the plurality of battery cells 21 are connected in series and some are connected in parallel. The plurality of battery cells 21 can be directly connected in series, in parallel, or in a mixed manner, and the battery cell module 20 formed by the plurality of battery cells 21 is accommodated in the shell 10. The battery cell module 20 can also include other structures, for example, the battery cell module 20 can also include a busbar component for realizing electrical connection between the plurality of battery cells 21.

[0072] Each of the battery cells 21 can be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cells 21 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. For example, in some embodiments, the battery cells 21 are in the shape of a cylinder. Figure 1 In some embodiments, the battery cells 21 are in the shape of a cuboid.

[0073] For example, in some embodiments, the battery cells 21 are in the shape of a cylinder. Figure 2 In some embodiments, the battery cells 21 are in the shape of a cuboid. Figure 3 In some embodiments, the housing 10 of the battery pack 100 is provided with two battery cell modules 20, and the two battery cell modules 20 are arranged along the second direction Y, which is perpendicular to the first direction X. The cover plate 40 covers one side of the housing 10 in the third direction Z. In other embodiments, the number of the battery cell modules 20 can also be one, three, four, or five, etc. It should be noted that when the battery cell modules 20 arranged in the housing 10 are multiple, the structural member 30 arranged between the battery cell modules 20 and one side plate 11 can be one or multiple, referring to Figure 3 and further referring to Figure 8 , Figure 8 The assembly schematic diagram of the battery cell module 20 and the structural member 30 provided in some embodiments of the present application can be that multiple battery cell modules 20 share one structural member 30, that is, one structural member 30 is arranged between the multiple battery cell modules 20 and one side plate 11. In other embodiments, the battery pack 100 can also be other structures, for example, referring to Figure 9 , Figure 9 The assembly schematic diagram of the battery cell module 20 and the structural member 30 in other embodiments provided in some embodiments of the present application can be that one structural member 30 is arranged corresponding to each battery cell module 20, that is, one structural member 30 is arranged between each battery cell module 20 and one side plate 11.

[0074] The structural member 30 and the battery cell module 20 are arranged along the first direction X, that is, in the first direction X, at least one side of the battery cell module 20 is provided with the structural member 30, which can be that one side of the battery cell module 20 in the first direction X is provided with the structural member 30, or both sides of the battery cell module 20 in the first direction X are provided with the structural member 30. It can be that the structural member 30 is arranged between the battery cell module 20 and one of the two side plates 11 (as shown in Figure 3 ), or the structural member 30 is arranged between the battery cell module 20 and the two side plates 11. For example, referring to Figure 10 , Figure 10The assembly schematic of the battery cell module 20 and the structural member 30 provided in some embodiments of the present application in other embodiments can be that the battery cell module 20 and the two side plates 11 are both provided with the structural member 30, that is, the battery cell module 20 is provided with the structural member 30 on both sides in the first direction X, and the one structural member 30, the battery cell module 20 and the other structural member 30 are sequentially arranged along the first direction X.

[0075] In the embodiments of the present application, the bending modulus refers to the strain generated by the bending stress, the ability to resist bending deformation within the elastic limit.

[0076] In the embodiments of the present application, the bending modulus refers to the strain generated by the bending stress, the ability to resist bending deformation within the elastic limit.

[0077] Optionally, the material of the structural member 30 can be various, such as metal material or high polymer synthetic material, etc. For example, in the embodiments of the present application, the material of the structural member 30 is metal material, such as aluminum or aluminum alloy, etc. The structural member 30 with metal material is beneficial to improve the toughness of the structural member 30 when it is collapsed and deformed, so as to make the structural member 30 provide more stable pressure for the battery cell module 20 in the first direction X, thereby being beneficial to improve the pressure effect of the structural member 30 on the battery cell module 20.

[0078] Similarly, the number of the side wall 31 of the structural member 30 can be various, such as two, three, four, five or six, etc. For example, in the embodiments of the present application, the number of the side wall 31 of the structural member 30 is two. Figure 5

[0079] ​The structure member 30 comprises a plurality of side walls 31 arranged along the first direction X in sequence with the battery cell module 20, the plurality of side walls 31 comprises a first side wall 311 and a second side wall 312, and the first side wall 311 and the second side wall 312 are respectively connected with the shell 10 and the battery cell module 20, that is, the structure member 30 comprises at least two side walls 31, and the two side walls 31 are respectively the first side wall 311 and the second side wall 312, and the first side wall 311 and the second side wall 312 are respectively located at two ends of the plurality of side walls 31 in the first direction X.

[0080] Each two adjacent side walls 31 are connected with a connecting portion 32, that is, each two adjacent side walls 31 are connected through the connecting portion 32 in the first direction X, and optionally, the number of the connecting portion 32 connected between the two adjacent side walls 31 can be one, two, three, four, five or six, etc. For example, in the embodiment shown in Figure 5 , the connecting portion 32 connected between the two adjacent side walls 31 is one, and the cross section of the connecting portion 32 is honeycomb-shaped.

[0081] It should be noted that in other embodiments, the structure member 30 can also be other structures, for example, referring to Figure 11 , the structure member 30 comprises a plurality of side walls 31 arranged along the first direction X in sequence with the battery cell module 20, the plurality of side walls 31 comprises a first side wall 311 and a second side wall 312, and the first side wall 311 and the second side wall 312 are respectively connected with the shell 10 and the battery cell module 20, that is, the structure member 30 comprises at least two side walls 31, and the two side walls 31 are respectively the first side wall 311 and the second side wall 312, and the first side wall 311 and the second side wall 312 are respectively located at two ends of the plurality of side walls 31 in the first direction X. Figure 11 , the structure member 30 comprises a plurality of side walls 31 arranged along the first direction X in sequence with the battery cell module 20, the plurality of side walls 31 comprises a first side wall 311 and a second side wall 312, and the first side wall 311 and the second side wall 312 are respectively connected with the shell 10 and the battery cell module 20, that is, the structure member 30 comprises at least two side walls 31, and the two side walls 31 are respectively the first side wall 311 and the second side wall 312, and the first side wall 311 and the second side wall 312 are respectively located at two ends of the plurality of side walls 31 in the first direction X. Figure 12 , the structure member 30 comprises a plurality of side walls 31 arranged along the first direction X in sequence with the battery cell module 20, the plurality of side walls 31 comprises a first side wall 311 and a second side wall 312, and the first side wall 311 and the second side wall 312 are respectively connected with the shell 10 and the battery cell module 20, that is, the structure member 30 comprises at least two side walls 31, and the two side walls 31 are respectively the first side wall 311 and the second side wall 312, and the first side wall 311 and the second side wall 312 are respectively located at two ends of the plurality of side walls 31 in the first direction X. Figure 12 , the structure member 30 comprises a plurality of side walls 31 arranged along the first direction X in sequence with the battery cell module 20, the plurality of side walls 31 comprises a first side wall 311 and a second side wall 312, and the first side wall 311 and the second side wall 312 are respectively connected with the shell 10 and the battery cell module 20, that is, the structure member 30 comprises at least two side walls 31, and the two side walls 31 are respectively the first side wall 311 and the second side wall 312, and the first side wall 311 and the second side wall 312 are respectively located at two ends of the plurality of side walls 31 in the first direction X. Figure 13 , the structure member 30 comprises a plurality of side walls 31 arranged along the first direction X in sequence with the battery cell module 20, the plurality of side walls 31 comprises a first side wall 311 and a second side wall 312, and the first side wall 311 and the second side wall 312 are respectively connected with the shell 10 and the battery cell module 20, that is, the structure member 30 comprises at least two side walls 31, and the two side walls 31 are respectively the first side wall 311 and the second side wall 312, and the first side wall 311 and the second side wall 312 are respectively located at two ends of the plurality of side walls 31 in the first direction X. Figure 14 , the structure member 30 comprises a plurality of side walls 31 arranged along the first direction X in sequence with the battery cell module 20, the plurality of side walls 31 comprises a first side wall 311 and a second side wall 312, and the first side wall 311 and the second side wall 312 are respectively connected with the shell 10 and the battery cell module 20, that is, the structure member 30 comprises at least two side walls 31, and the two side walls 31 are respectively the first side wall 311 and the second side wall 312, and the first side wall 311 and the second side wall 312 are respectively located at two ends of the plurality of side walls 31 in the first direction X. Figure 13 , the structure member 30 comprises a plurality of side walls 31 arranged along the first direction X in sequence with the battery cell module 20, the plurality of side walls 31 comprises a first side wall 311 and a second side wall 312, and the first side wall 311 and the second side wall 312 are respectively connected with the shell 10 and the battery cell module 20, that is, the structure member 30 comprises at least two side walls 31, and the two side walls 31 are respectively the first side wall 311 and the second side wall 312, and the first side wall 311 and the second side wall 312 are respectively located at two ends of the plurality of side walls 31 in the first direction X. Figure 14Assembled schematic view of the structural member 30 and the battery cell module 20 is provided for other embodiments of the present application, the structural member 30 includes a second side wall 312 and two first side walls 311, the two first side walls 311 are arranged at intervals along the second direction Y, and a connecting portion 32 is connected between each first side wall 311 and the second side wall 312, and the connecting portion 32 is arranged at an acute angle with the first side wall 311 and the second side wall 312, so that the structural member 30 forms a shape similar to a "j" character structure. The use stability of the structural member 30 with this structure is better, so that the structural member 30 stably collapses and deforms along the first direction X when the battery cell 21 of the battery cell module 20 expands.

[0082] Optionally, the forming method of the structural member 30 can be various, for example, the structural member 30 can be made by casting, stamping or extrusion forming process, etc.

[0083] Among them, the first side wall 311 is connected with the shell 10, and the connection mode of the first side wall 311 with the shell 10 can be various, such as welding, bonding, clamping or bolted connection, etc. Similarly, the second side wall 312 is connected with the battery cell module 20, and in the embodiment of the present application, the second side wall 312 and the battery cell module 20 abut each other along the first direction X. It should be noted that the second side wall 312 and the battery cell module 20 can be in direct abutment relationship, or in indirect abutment relationship, that is, other components can also be provided between the second side wall 312 and the battery cell module 20.

[0084] In some embodiments, referring to FIGS. Figure 2 and Figure 8 The battery pack 100 can also include an insulating member 50. Along the first direction X, the insulating member 50 is arranged between the battery cell module 20 and the structural member 30 to separate the battery cell module 20 and the structural member 30. The battery pack 100 with this structure can insulate and isolate the battery cell module 20 and the structural member 30, so as to reduce the risk of short circuit of the battery pack 100 in use, thereby facilitating to improve the use safety of the battery pack 100.

[0085] Among them, the insulating member 50 can be various, such as rubber pad, silica gel pad or plastic pad, etc. arranged between the battery cell module 20 and the structural member 30, so as to insulate and isolate the battery cell module 20 and the structural member 30. Of course, the insulating member 50 can also be a foam arranged between the battery cell module 20 and the structural member 30, so as to insulate and isolate the battery cell module 20 and the structural member 30, and also provide a certain buffering effect between the battery cell module 20 and the structural member 30.

[0086] According to some embodiments of the present application, the bending modulus of the shell 10 is greater than the bending modulus of the side wall 31.

[0087] By setting the bending modulus of the shell 10 to be greater than the bending modulus of the side wall 31, the anti-deformation ability of the shell 10 is stronger than the structural member 30, so as to reduce the deformation of the shell 10 during use, and facilitate the shell 10 to provide better stability and support effects for the structural member 30.

[0088] According to some embodiments of the present application, referring to Figure 4 and Figure 5 , the bending modulus of the first side wall 311 is greater than the bending modulus of the second side wall 312. The anti-deformation ability of the structural member 30 connected to the first side wall 311 of the shell 10 is greater than the anti-deformation ability of the structural member 30 abutting the second side wall 312 of the battery cell module 20.

[0089] By setting the bending modulus of the first side wall 311 to be greater than the bending modulus of the second side wall 312, the anti-deformation ability of the first side wall 311 is stronger than the second side wall 312, so as to make the first side wall 311 connected to the shell 10 provide better stability and support effects for the structural member 30, thereby facilitating to reduce the phenomenon that the structural member 30 cannot provide pressure along the first direction X for the battery cell module 20 due to the deformation of the first side wall 311, so as to improve the pressure effect of the structural member 30 on the battery cell module 20.

[0090] According to some embodiments of the present application, referring to Figure 15 , as shown in the front view of the structural member 30 provided by yet some embodiments of the present application, Figure 15 , the thickness of the first side wall 311 along the first direction X is greater than or equal to the thickness of the second side wall 312.

[0091] Among them, in Figure 15 , the thickness of the first side wall 311 along the first direction X is D1, and the thickness of the second side wall 312 along the first direction X is D2, D1≥D2.

[0092] By setting the thickness of the first side wall 311 along the first direction X to be greater than or equal to the thickness of the second side wall 312, the structural strength of the first side wall 311 is greater than or equal to the structural strength of the second side wall 312, so as to make the first side wall 311 connected to the shell 10 provide better stability and support effects for the structural member 30.

[0093] In some embodiments, referring to Figure 5 and Figure 8As shown, along the first direction X, the distance between the first sidewall 311 and the second sidewall 312 is greater than or equal to 10% of the length of the cell module 20. That is, in the first direction X, the distance between the first sidewall 311 and the second sidewall 312 is greater than or equal to 10% of the size of the cell module 20, i.e., in the first direction X, the distance between the first sidewall 311 and the second sidewall 312 is greater than or equal to 10% of the overall thickness of the stacked multiple cells 21.

[0094] By setting the distance between the first sidewall 311 and the second sidewall 312 to be greater than or equal to 10% of the size of the cell module 20 in the first direction X, the distance between the first sidewall 311 and the second sidewall 312 in the first direction X is greater than the maximum expansion amount of the cell module 20 in the first direction X. This ensures that the structural component 30 provides sufficient expansion space for the cell module 20 when it collapses and deforms along the first direction X, thereby reducing the safety hazards caused by insufficient expansion space of the cell 21.

[0095] According to some embodiments of this application, refer to Figure 16 , Figure 16 This is a front view of a structural member 30 provided in some further embodiments of this application. The number of sidewalls 31 is at least three, with other sidewalls 31 located between a first sidewall 311 and a second sidewall 312. The flexural modulus of the first sidewall 311 is greater than that of the other sidewalls 31, and the flexural modulus of the second sidewall 312 is greater than that of the other sidewalls 31.

[0096] The number of sidewalls 31 is at least three, meaning the structural member 30 can have three, four, five, or six sidewalls 31, etc. For example, in... Figure 16 In the structure, the number of sidewalls 31 of the structural member 30 is five, that is, three sidewalls 31 are arranged in sequence between the first sidewall 311 and the second sidewall 312.

[0097] By setting the bending modulus of the first sidewall 311 and the second sidewall 312 of the structural member 30 to be greater than the bending modulus of the other sidewalls 31 of the structural member 30, and with the other sidewalls 31 all located between the first sidewall 311 and the second sidewall 312, the deformation resistance of the first sidewall 311 and the second sidewall 312 located at both ends of the structural member 30 in the first direction X is greater than the deformation resistance of the sidewall 31 located between the first sidewall 311 and the second sidewall 312. This achieves preferential deformation of the sidewall 31 located between the first sidewall 311 and the second sidewall 312, thereby mitigating the deformation of the first sidewall 311 and the second sidewall 312 during use. This, in turn, helps to improve the connection reliability between the first sidewall 311 and the housing 10 and the connection reliability between the second sidewall 312 and the battery module 20.

[0098] According to some embodiments of the present application, please refer to Figure 16 As shown in FIG. 1, the plurality of side walls 31 further comprises a third side wall 313, which is located between the first side wall 311 and the second side wall 312 along the first direction X. That is, the first side wall 311, the third side wall 313, the second side wall 312 and the battery cell module 20 are arranged in sequence along the first direction X.

[0099] By arranging the third side wall 313 between the first side wall 311 and the second side wall 312, it is convenient for manufacturing, and is conducive to improving the overall structural stability of the structural member 30, and is conducive to relieving the phenomenon that the structural member 30 laterally deforms along a direction perpendicular to the first direction X during the collapse deformation along the first direction X.

[0100] Wherein, along the first direction X, the distance between the first side wall 311 and the third side wall 313 is less than the distance between the third side wall 313 and the second side wall 312.

[0101] By setting the distance between the first side wall 311 and the third side wall 313 to be less than the distance between the third side wall 313 and the second side wall 312, the area between the third side wall 313 and the second side wall 312 of the structural member 30 is more prone to collapse deformation along the first direction X, thereby relieving the impact of the structural member 30 on the first side wall 311 during the collapse deformation, and further facilitating the stability of the first side wall 311 connected to the shell 10, and improving the supporting effect of the first side wall 311 on other side walls 31.

[0102] In some embodiments, along the first direction X, the distance between the second side wall 312 and the third side wall 313 is greater than or equal to 10% of the length of the battery cell module 20. That is, along the first direction X, the distance between the second side wall 312 and the third side wall 313 is greater than or equal to 10% of the size of the battery cell module 20, that is, along the first direction X, the distance between the second side wall 312 and the third side wall 313 is greater than or equal to 10% of the overall thickness of the plurality of battery cells 21 after being stacked.

[0103] In actual use, the maximum expansion amount of each battery cell 21 is about 8% of the thickness of the battery cell 21, therefore, by setting the distance between the second side wall 312 and the third side wall 313 to be greater than or equal to 10% of the size of the battery cell module 20 along the first direction X, the size of the area where the structural member 30 is more prone to deformation is greater than the maximum expansion amount of the battery cell module 20 along the first direction X, thereby realizing that the structural member 30 provides sufficient expansion space for the battery cell module 20 when collapsing and deforming along the first direction X, so as to reduce the use safety hazards caused by insufficient expansion space of the battery cell 21.

[0104] According to some embodiments of the present application, please continue to refer to Figure 16As shown, the plurality of side walls 31 further comprises a fourth side wall 314, which is located between the third side wall 313 and the second side wall 312 along the first direction X. That is, the first side wall 311, the third side wall 313, the fourth side wall 314, the second side wall 312 and the battery cell module 20 are arranged in sequence along the first direction X.

[0105] By arranging the fourth side wall 314 between the third side wall 313 and the second side wall 312, on the one hand, it is convenient to manufacture, and on the other hand, it further improves the overall structural stability of the structural member 30, which is conducive to relieving the phenomenon of lateral deformation along the direction perpendicular to the first direction X during the collapse deformation of the structural member 30 along the first direction X.

[0106] Among them, along the first direction X, the distance between the third side wall 313 and the fourth side wall 314 is greater than the distance between the first side wall 311 and the third side wall 313; and / or, along the first direction X, the distance between the third side wall 313 and the fourth side wall 314 is greater than the distance between the fourth side wall 314 and the second side wall 312.

[0107] By arranging the distance between the third side wall 313 and the fourth side wall 314 to be greater than the distance between the first side wall 311 and the third side wall 313, the area of the structural member 30 between the third side wall 313 and the fourth side wall 314 is more prone to collapse deformation along the first direction X, thereby relieving the impact of the structural member 30 on the first side wall 311 during the collapse deformation, thereby facilitating the stability of the first side wall 311 connected to the shell 10, and facilitating the supporting effect of the first side wall 311 on other side walls 31. Similarly, by arranging the distance between the third side wall 313 and the fourth side wall 314 to be greater than the distance between the fourth side wall 314 and the second side wall 312, the area where the structural member 30 is more prone to collapse deformation is away from the second side wall 312, which is conducive to reducing the impact of the structural member 30 on the second side wall 312 during the collapse deformation, thereby facilitating the reliability of the mutual connection between the second side wall 312 and the battery cell module 20.

[0108] In some embodiments, along the first direction X, the distance between the third side wall 313 and the fourth side wall 314 is greater than or equal to 10% of the length of the battery cell module 20. That is, along the first direction X, the distance between the third side wall 313 and the fourth side wall 314 is greater than or equal to 10% of the size of the battery cell module 20, that is, along the first direction X, the distance between the third side wall 313 and the fourth side wall 314 is greater than or equal to 10% of the overall thickness of the plurality of battery cells 21 after being stacked.

[0109] By setting the distance between the third side wall 313 and the fourth side wall 314 to be greater than or equal to 10% of the size of the battery cell module 20 in the first direction X, the size of the region where the structural member 30 is more easily deformed is greater than the maximum expansion amount of the battery cell module 20 in the first direction X, so that the structural member 30 provides sufficient expansion space for the battery cell module 20 when it is deformed in the collapse direction along the first direction X, thereby reducing the risk of safety hazards caused by insufficient expansion space of the battery cell 21.

[0110] According to some embodiments of the present application, please continue to refer to Figure 16 As shown, the plurality of side walls 31 further includes a fifth side wall 315, which is located between the third side wall 313 and the fourth side wall 314 along the first direction X. That is, the first side wall 311, the third side wall 313, the fifth side wall 315, the fourth side wall 314, the second side wall 312 and the battery cell module 20 are arranged in sequence along the first direction X.

[0111] By providing the fifth side wall 315 between the third side wall 313 and the fourth side wall 314, it is convenient to manufacture, and further improves the overall structural stability of the structural member 30, which is conducive to alleviating the phenomenon of side displacement deformation of the structural member 30 in the direction perpendicular to the first direction X during the collapse deformation along the first direction X.

[0112] Optionally, the distance between the third side wall 313 and the fifth side wall 315 along the first direction X is greater than the distance between the first side wall 311 and the third side wall 313; and / or, the distance between the third side wall 313 and the fifth side wall 315 along the first direction X is greater than the distance between the fourth side wall 314 and the second side wall 312.

[0113] By setting the distance between the third side wall 313 and the fifth side wall 315 to be greater than the distance between the first side wall 311 and the third side wall 313, the region of the structural member 30 between the third side wall 313 and the fifth side wall 315 is more easily deformed in the first direction X, thereby alleviating the impact of the structural member 30 on the first side wall 311 during the collapse deformation, which is conducive to the stability of the first side wall 311 connected to the shell 10 and improves the supporting effect of the first side wall 311 on other side walls 31. Similarly, by setting the distance between the third side wall 313 and the fifth side wall 315 to be greater than the distance between the fourth side wall 314 and the second side wall 312, the region of the structural member 30 that is more easily deformed is away from the second side wall 312, which is conducive to reducing the impact of the structural member 30 on the second side wall 312 during the collapse deformation, thereby improving the reliability of the connection between the second side wall 312 and the battery cell module 20.

[0114] Optionally, the distance between the fourth side wall 314 and the fifth side wall 315 is greater than the distance between the first side wall 311 and the third side wall 313 along the first direction X; and / or, the distance between the fourth side wall 314 and the fifth side wall 315 is greater than the distance between the fourth side wall 314 and the second side wall 312 along the first direction X.

[0115] By setting the distance between the fourth side wall 314 and the fifth side wall 315 greater than the distance between the first side wall 311 and the third side wall 313, the area between the fourth side wall 314 and the fifth side wall 315 where the structural member 30 is more likely to collapse along the first direction X, thereby reducing the impact of the structural member 30 on the first side wall 311 during the collapse, which is conducive to the stability of the first side wall 311 connected to the shell 10 and improves the supporting effect of the first side wall 311 on other side walls 31. Similarly, by setting the distance between the fourth side wall 314 and the fifth side wall 315 greater than the distance between the fourth side wall 314 and the second side wall 312, the area where the structural member 30 is more likely to collapse is away from the second side wall 312, which is conducive to reducing the impact of the structural member 30 on the second side wall 312 during the collapse, thereby facilitating the reliability of the connection between the second side wall 312 and the battery module 20.

[0116] According to some embodiments of the present application, referring to Figure 1 , and further referring to Figure 17 , Figure 17 a structural schematic diagram of a power utilization device 1000 provided by some embodiments of the present application. The embodiments of the present application also provide a power utilization device 1000, which includes the battery pack 100 of any of the above solutions, and the battery pack 100 is used to provide power for the power utilization device 1000.

[0117] The power utilization device 1000 can be a device or system of any of the above applications of the battery pack 100.

[0118] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0119] The above is only preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A battery pack, characterized by, The battery pack comprises: a shell; a battery cell module at least partially accommodated in the shell, the battery cell module comprising a plurality of battery cells stacked along a first direction; and a structural member arranged along the first direction with the battery cell module; wherein the structural member comprises a plurality of side walls arranged along the first direction with the battery cell module in sequence, each adjacent two of the side walls being connected by a connecting portion, a bending modulus of each connecting portion being less than a bending modulus of each of the two side walls connected by the connecting portion, the plurality of side walls comprising a first side wall and a second side wall, the first side wall being connected with the shell, the second side wall being connected with the battery cell module, the first side wall and the second side wall being located at two ends of the plurality of side walls along the first direction. The bending modulus of the shell is greater than the bending modulus of the side walls.

2. The battery pack of claim 1, wherein, The bending modulus of the first side wall is greater than the bending modulus of the second side wall.

3. The battery pack of claim 1, wherein, The distance between the first side wall and the second side wall along the first direction is greater than or equal to 10% of the length of the battery cell module.

4. The battery pack of claim 1, wherein, The number of the side walls is at least three, other side walls being located between the first side wall and the second side wall, the bending modulus of the first side wall being greater than the bending modulus of the other side walls, the bending modulus of the second side wall being greater than the bending modulus of the other side walls.

5. The battery pack of any one of claims 1-4, wherein, The plurality of side walls further comprises a third side wall, the distance between the first side wall and the third side wall along the first direction being less than the distance between the third side wall and the second side wall along the first direction.

6. The battery pack of claim 5, wherein, The distance between the second side wall and the third side wall along the first direction is greater than or equal to 10% of the length of the battery cell module.

7. The battery pack of claim 6, wherein, The plurality of side walls further comprises a fourth side wall, the distance between the third side wall and the fourth side wall along the first direction being greater than the distance between the first side wall and the third side wall along the first direction; and / or 8. The battery pack of claim 6, wherein, The distance between the third side wall and the fourth side wall along the first direction is greater than the distance between the fourth side wall and the second side wall along the first direction. The distance between the third side wall and the fourth side wall along the first direction is greater than or equal to 10% of the length of the battery cell module.

9. The battery pack of claim 8, wherein, The plurality of side walls further comprises a fifth side wall, the fifth side wall being located between the third side wall and the fourth side wall, the distance between the third side wall and the fifth side wall along the first direction being greater than the distance between the first side wall and the third side wall along the first direction; and / or 10. The battery pack of claim 8, wherein, The distance between the third side wall and the fifth side wall along the first direction is greater than the distance between the fourth side wall and the second side wall along the first direction. The distance between the fourth side wall and the fifth side wall along the first direction is greater than the distance between the first side wall and the third side wall along the first direction; and / or 11. The battery pack of claim 10, wherein, The distance between the fourth side wall and the fifth side wall along the first direction is greater than the distance between the fourth side wall and the second side wall along the first direction. The battery pack comprises the battery pack according to any one of claims 1-11.

12. An electrical device, comprising: ​

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