Battery pack and electric equipment

Abstract

The utility model discloses a battery pack and electric equipment, and belongs to the technical field of batteries, the battery pack is characterized in that a first end plate is arranged in an accommodating cavity of a box body, the first end plate is arranged in a battery pack, battery monomers are arranged on two opposite sides of the first end plate in a first direction, and a first through hole is formed in the first end plate; the first fixing piece penetrates through the first through hole, one end of the two opposite ends of the first fixing piece is fixedly connected with the first wall of the box body, the other end of the first fixing piece penetrates through the second wall of the box body and extends out of the box body, and the end, penetrating through the second wall and extending out of the outer side of the box body, of the first fixing piece can be connected with electric equipment; the first end plate can replace a cross beam in an existing battery pack for use, the structural strength of the box body in the first direction is guaranteed, meanwhile, the length of the battery pack in the first direction is guaranteed, the battery pack is provided with more battery monomers in the first direction, and the battery pack is more stable in use. The energy density of the battery pack is improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly relates to a battery pack and an electrical device. Background Art

[0002] In an existing battery pack, in order to ensure the structural strength of the box body in the length direction, a cross beam is provided in the middle section in the length direction inside the box body, and long bolts for locking with the electrical device are provided on the cross beam. As a result, the battery pack inside the box body cannot span the cross beam in the length direction, and the length of the battery pack in the length direction is limited, affecting the energy density of the battery pack. Summary of the Utility Model

[0003] The purpose of the present utility model is to provide a battery pack and an electrical device to solve the problem that the length of the battery pack in the length direction is limited in the current battery pack.

[0004] In a first aspect of an embodiment of the present application, a battery pack is provided, having intersecting first and third directions. The battery pack includes: a box body with an accommodation cavity inside, the box body including a first wall and a second wall oppositely arranged along the third direction; a battery pack disposed in the accommodation cavity, the battery pack including a plurality of battery monomers spaced along the first direction; a first end plate disposed in the battery pack, with battery monomers arranged on both opposite sides of the first end plate along the first direction, and a first through hole penetrating the first end plate along the third direction is provided on the first end plate; a first fixing member passing through the first through hole, and along the third direction, one end of the opposite ends of the first fixing member is fixedly connected to the first wall, and the other end penetrates the second wall and extends to the outside of the box body.

[0005] Optionally, the battery pack further includes a cross beam disposed in the accommodation cavity and fixedly connected to the first wall; along the third direction, the first end plate and the cross beam are stacked, and one end of the first fixing member close to the cross beam is fixedly connected to the cross beam.

[0006] Optionally, along the third direction, a groove is provided on a surface of the first end plate facing the cross beam, the cross beam is embedded in the groove, and the first fixing member passes through the bottom of the groove and is fixedly connected to the cross beam.

[0007] Optionally, the battery pack further has a second direction, and the first, second, and third directions intersect pairwise; the battery pack further includes a side plate extending along the first direction, the side plate is disposed on at least one of the opposite sides of the battery pack in the second direction; the side plate is welded to the first end plate.

[0008] Optionally, along the second direction, at least two first positioning holes are formed at one end of the first end plate adjacent to the side plate, at least two second positioning holes are formed on the side plate, the number of the first positioning holes is equal to that of the second positioning holes, and one of the first positioning holes is arranged opposite to one of the second positioning holes; a first welding mark is formed at the welding position between the side plate and the first end plate, and the first welding mark surrounds the first positioning hole and the second positioning hole to form a ring; among at least two of the second positioning holes, any two of the second positioning holes respectively have a center point, the center point has a center line extending along the third direction, and the distance between two center lines along the first direction is L1 mm; the first welding mark has two maximum contour points arranged opposite to each other along the first direction, and the two maximum contour points respectively have extension lines extending along the third direction, and the distance L2 mm between the two extension lines along the first direction is the maximum dimension of the first welding mark in the first direction; it satisfies that: L1 < L2.

[0009] Optionally, the battery pack further has a second direction, and the first direction, the second direction and the third direction intersect pairwise; the battery pack further includes a pressing strip and a second fixing member; along the third direction, the first end plate has a first end face facing the second wall, and a second through hole penetrating through the first end plate is formed on the first end plate; the pressing strip is arranged on the first end face, the second fixing member penetrates through the pressing strip along the third direction, and the second fixing member is inserted into the second through hole and fixedly connected to the cross beam to fix the first end plate on the cross beam.

[0010] Optionally, the battery cell includes a first face facing the second wall along the third direction, and the second wall has a first surface facing the first end plate; along the third direction, the distance between the plane where the first end face is located and the plane where the first surface is located is L3 mm, the distance between the plane where the first face is located and the plane where the first surface is located is L4 mm, and the distance between the plane where the side of the pressing strip facing the second wall is located and the plane where the first surface is located is L5 mm; it satisfies that: L4 < L5 < L3.

[0011] Optionally, the battery pack further includes a flexible circuit board; the battery pack includes a first battery pack and a second battery pack spaced apart along the first direction, the first end plate is disposed between the first battery pack and the second battery pack, and the first battery pack and the second battery pack each include a plurality of battery cells spaced apart along the first direction; the flexible circuit board includes a first circuit board, a second circuit board, and a connection section; along the third direction, the first circuit board is disposed on a surface of the first battery pack facing the second wall, and the second circuit board is disposed on a surface of the second battery pack facing the second wall; along the first direction, two adjacent ends of the first circuit board and the second circuit board are connected by the connection section; along the third direction, the connection section is stacked with the first end surface, the pressing strip is disposed on a surface of the connection section facing away from the first end surface, and along the second direction, the connection section and the second fixing member are spaced apart.

[0012] Optionally, along the third direction, the connection section is recessed away from the second wall to form a recess and is stacked with the first end surface, and the pressing strip is embedded in the recess.

[0013] A second aspect of the embodiments of the present application provides an electrical device including the battery pack as described above.

[0014] In summary, the embodiments of the present application provide a battery pack and an electrical device having the battery pack. The battery pack is provided with a first end plate in the accommodation cavity of the box body. The first end plate is disposed in the battery pack. Battery cells are disposed on opposite sides of the first end plate in the first direction. A first through hole penetrating the first end plate in the third direction is opened on the first end plate, and a first fixing member is passed through the first through hole. One end of the opposite ends of the first fixing member in the third direction is fixedly connected to the first wall of the box body, and the other end penetrates the second wall of the box body and extends to the outside of the box body. One end of the first fixing member penetrating the second wall and extending outside the box body can be connected to the electrical device to ensure the assembly stability between the battery pack and the electrical device. The first end plate can be used instead of the cross beam in the existing battery pack. While ensuring the structural strength of the box body in the first direction, the length of the battery pack in the first direction is ensured, so that more battery cells can be arranged in the battery pack in the first direction, and the energy density of the battery pack is improved. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1It is a schematic structural diagram of the battery pack provided by the embodiment of the present application;

[0017] Figure 2 It is Figure 1 a sectional view taken along the A-A direction of

[0018] Figure 3 It is Figure 2 an enlarged schematic structural diagram at position B of

[0019] Figure 4 Figure 3 a combined structural schematic diagram of the battery cell, the second wall, the first end plate, the cross beam and the first wall in

[0020] Figure 5 It is Figure 1 a partial exploded view of

[0021] Figure 6 It is Figure 5 a structural schematic diagram of after removing the box body and the cross beam;

[0022] Figure 7 It is Figure 6 an enlarged schematic structural diagram at position C of

[0023] Figure 8 It is Figure 6 an enlarged schematic structural diagram at position D of

[0024] Figure 9 It is Figure 6 an exploded view of after removing the pressure strip;

[0025] Figure 10 It is a schematic structural diagram of the first end plate of the battery pack provided by the embodiment of the present application at the first angle;

[0026] Figure 11 It is a schematic structural diagram of the side plate of the battery pack provided by the embodiment of the present application;

[0027] Figure 12 It is a schematic structural diagram of the flexible circuit board of the battery pack provided by the embodiment of the present application;

[0028] Figure 13 It is a schematic structural diagram of the battery cell of the battery pack provided by the embodiment of the present application.

[0029] Main reference numeral description:

[0030] 1. Battery pack;

[0031] 10. Box body, 101. Accommodation cavity, 11. First wall, 12. Second wall, 13. Third wall, 14. Fourth wall, 15. Fifth wall, 16. Sixth wall, 121. First surface, 122. Second surface;

[0032] 20. Battery pack, 201. First battery pack, 202. Second battery pack, 21. Battery cell, 211. First side, 212. Second side, 213. Third side, 214. Fourth side, 215. Fifth side, 216. Sixth side, 22. Terminal post, 23. Conductive bar, 24. Insulating sheet;

[0033] 30. First end plate, 31. First through hole, 32. Groove, 321. Bottom of the groove, 322. Wall of the groove, 33. First positioning hole, 34. First end face, 35. Second through hole, 36. Third positioning hole;

[0034] 40. First fixing member, 41. Second fixing member;

[0035] 50. Cross beam;

[0036] 60. Side plate, 61. Second positioning hole, 611. Center point, 612. Center line, 62. First welding mark, 621. Maximum contour point, 622. Extension line, 63. Bent portion, 64. Protruding portion, 65. Second welding mark;

[0037] 70. Batten, 71. Third through hole, 72. Fourth through hole;

[0038] 80. Flexible circuit board, 81. First circuit board, 82. Second circuit board, 83. Connection section, 831. Concave portion;

[0039] 90. Second end plate, 91. Electrical isolation board, 92. Cover plate;

[0040] X. First direction, Y. Second direction, Z. Third direction. Detailed implementation manner

[0041] In order to make the purpose, technical solution and beneficial effects of this application clearer and more understandable, the following further elaborates on this application in combination with the accompanying drawings and specific implementation manners. It should be understood that the specific implementation manners described in this specification are only for explaining this application and not for limiting this application.

[0042] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0043] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0044] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the term "stacked" shall be understood in a broad sense. For example, it may be a direct contact connection between two elements, or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0045] In the present application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0046] In the application embodiments, "parallel" refers to a state where the angle formed by a straight line and a straight line, a straight line and a plane, or a plane and a plane is -1° to 1°. Additionally, "perpendicular" refers to a state where the angle formed by a straight line and a straight line, a straight line and a plane, or a plane and a plane is 89° to 91°. Equal distance or equal angle refers to a state where the tolerance range is -1% to 1%.

[0047] This embodiment provides an electrical device, including a battery pack 1, and the battery pack 1 serves as the power supply for the electrical device. The electrical device can be, but is not limited to, a mobile device (such as a mobile phone, a laptop computer, etc.), an electric vehicle (such as a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.), an electric train, a ship, a satellite, an energy storage system, etc.

[0048] In some embodiments of the present application, a battery pack 1 is provided. Referring to Figures 1 to 7 , Figures 9 to 10 and Figure 13 , the battery pack 1 includes: a box body 10, a battery pack 20, a first end plate 30, and a first fixing member 40. Referring to Figures 1 to 9 , the battery pack 1 has a first direction X, a second direction Y, and a third direction Z that intersect pairwise. Specifically, in the embodiment shown in Figures 1 to 9 , the first direction X, the second direction Y, and the third direction Z are pairwise orthogonal.

[0049] Referring to Figure 2 and Figure 5 , an accommodation cavity 101 is provided inside the box body 10. Referring to Figures 1 to 5 , the box body 10 includes a first wall 11 and a second wall 12 that are oppositely arranged along the third direction Z. Referring to Figure 1 , the box body 10 further includes a third wall 13 and a fourth wall 14 that are oppositely arranged along the first direction X, and a fifth wall 15 and a sixth wall 16 that are oppositely arranged along the second direction Y. The third wall 13, the fifth wall 15, the fourth wall 14, and the sixth wall 16 are sequentially connected to form a tetrahedral structure with both ends open in the third direction Z. The first wall 11 and the second wall 12 are respectively covered on both ends of the opening to define the accommodation cavity 101 inside. Specifically, in the embodiment shown in Figures 1 to 5 , the first direction X is parallel to the length direction of the box body 10, the second direction Y is parallel to the width direction of the box body 10, and the third direction Z is parallel to the height direction of the box body 10.

[0050] Referring to Figure 4 and Figure 9 , the battery pack 20 is disposed in the accommodation cavity 101 of the box body 10. The battery pack 20 includes a plurality of battery cells 21 that are spaced apart along the first direction X. Referring to Figure 13, the battery cell 21 includes a first surface 211 and a second surface 212 oppositely arranged along the third direction Z, a third surface 213 and a fourth surface 214 oppositely arranged along the first direction X, and a fifth surface 215 and a sixth surface 216 oppositely arranged along the second direction Y. The third surface 213, the fifth surface 215, the fourth surface 214, and the sixth surface 216 are sequentially connected end to end to form a housing structure with both ends open. The first surface 211 and the second surface 212 respectively cover the two open ends to form a closed hexahedron. The third surface 213 and the fourth surface 214 are the surfaces with the largest surface area among the six surfaces. Refer to Figure 4 , along the third direction Z, the first surface 211 is adjacent to the second wall 12 of the box body 10, and the second surface 212 is adjacent to the first wall 11 of the box body 10.

[0051] Refer to Figures 3 to 4 , Figure 7 , Figure 9 and Figure 10 , the first end plate 30 is disposed in the battery pack 20. On both opposite sides of the first end plate 30 along the first direction X, battery cells 21 are disposed. Specifically, along the first direction X, one side of the first end plate 30 abuts against the third surface 213 of the adjacent battery cell 21, and the other side of the first end plate 30 abuts against the fourth surface 214 of the adjacent battery cell 21. Refer to Figure 7 and Figure 10 , a first through hole 31 penetrating the first end plate 30 along the third direction Z is formed on the first end plate 30.

[0052] Refer to Figures 1 to 4 , the first fixing member 40 is inserted into the first through hole 31. Along the third direction Z, one end of the two opposite ends of the first fixing member 40 is fixedly connected to the first wall 11 of the box body 10, and the other end penetrates through the second wall 12 of the box body 10 and extends to the outside of the box body 10. Specifically, the fixing member 40 includes two ends oppositely arranged along the third direction Z. One end is fixedly connected to the first wall 11, and the other end penetrates through the second wall 12 and extends to the outside of the box body 10 to be connected to the electrical device, thereby fixedly installing the battery pack 1 in the electrical device.

[0053] To ensure the structural strength of the box body in the length direction, a cross beam is provided in the middle section in the length direction inside the box body of the battery pack, and long bolts are provided on the cross beam. The battery pack is attached to the electrical device through the long bolts. However, the setting of the cross beam and the long bolts inside the box body results in that the battery pack inside the box body cannot span the cross beam and the long bolts in the length direction. The limited length of the battery pack in the length direction leads to the inability to arrange more battery cells in the length direction, affecting the energy density of the battery pack.

[0054] The battery pack 1 provided by the embodiment of the present application is configured by disposing a first end plate 30 in the accommodation cavity 101 of the box body 10. The first end plate 30 is disposed in the battery pack 20. The battery pack 20 includes a plurality of battery cells 21 arranged along the first direction X. The battery cells 21 are disposed on both opposite sides of the first end plate 30 in the first direction X. That is, the first end plate 30 is disposed in the box body 10 as a middle end plate, and a first through hole 31 penetrating the first end plate 30 along the third direction Z is formed in the first end plate 30. A first fixing member 40 is inserted into the first through hole 31. One end of the opposite ends of the first fixing member 40 along the third direction Z is fixedly connected to the first wall 11 of the box body 10, and the other end penetrates the second wall 12 of the box body 10 and extends to the outside of the box body 10, so that the battery pack 1 can be locked and connected to the electrical device through the first fixing member 40, thereby ensuring the assembly stability between the battery pack 1 and the electrical device. The cooperation of the first end plate 30 and the first fixing member 40 can replace the cross beam in the existing battery pack, and can ensure the structural strength of the box body 10 in the first direction X. Moreover, the formation of the first through hole 31 in the first end plate 30 enables the first fixing member 40 to be inserted into the first through hole 31 to realize the locking between the battery pack 1 and the electrical device. Furthermore, the first fixing member 40 will not interfere with the battery pack 20 in the first direction X, so that the battery pack 20 can span the first end plate 30 in the first direction X without interfering with the first end plate 30, ensuring the continuity of the length of the battery pack 20 in the first direction X, enabling more battery cells 21 to be arranged in the battery pack 20 in the first direction X, improving the space utilization rate inside the box body 10, and further improving the energy density of the battery pack 1.

[0055] In some embodiments, the electrical device is an electric vehicle, and the first fixing member 40 serves as a lug to lock the battery pack 1 to the chassis of the electric vehicle.

[0056] In some embodiments, referring to Figures 2 to 4, the battery pack 1 further includes a cross beam 50 disposed in the accommodation cavity 101 and fixedly connected to the first wall 11. The cross beam 50 extends along the second direction Y. Along the third direction Z, the first end plate 30 is stacked with the cross beam 50. One end of the first fixing member 40 close to the cross beam 50 is fixedly connected to the cross beam 50. The arrangement of the cross beam 50, stacked with the first end plate 30 along the third direction Z, enables one end of the first fixing member 40 close to the cross beam 50 to be fixedly connected to the first wall 11 of the box body 10 through the cross beam 50, thereby further enhancing the connection strength between the first fixing member 40 and the first wall 11 and improving the locking stability between the battery pack 1 and the electrical equipment through the first fixing member 40. Moreover, the structural design in which the cross beam 50 and the first end plate 30 are stacked along the third direction Z and the cross beam 50 is disposed on the first wall 11 ensures that the cross beam 50 does not affect the continuity of the arrangement of the battery cells 21 in the battery pack 20 in the first direction X, does not interfere with the arrangement of the battery cells 21 in the first direction X, and can increase the overall strength of the middle section of the length of the box body 10 in the first direction X. Wherein, the first end plate 30 is stacked with the cross beam 50, that is, the first end plate 30 is directly connected to the cross beam 50 along the third direction Z.

[0057] In some embodiments, referring to Figures 3 to 4 , Figures 6 to 7 and Figure 10 , along the third direction Z, a groove 32 is formed on the surface of the first end plate 30 facing the cross beam 50. The cross beam 50 is embedded in the groove 32, and the first fixing member 40 passes through the bottom 321 of the groove 32 and is fixedly connected to the cross beam 50. Specifically, referring to Figure 3 and Figure 3 , the groove 32 is defined by the bottom 321 and the groove walls 322 disposed on the opposite sides of the bottom 321 in the first direction X. The cross beam 50 is embedded in the groove 32 and stacked with the bottom 321 along the third direction Z. The first through hole 31 penetrates the bottom 321 along the third direction Z, and the first fixing member 40 passes through the bottom 321 and is fixedly connected to the cross beam 50. The formation of the groove 32 can reduce the overall weight of the first end plate 30, provide an accommodation space for the cross beam 50, improve the utilization rate of the internal space of the box body 10, and increase the energy density of the battery pack 1.

[0058] In some embodiments, referring to Figure 7 and Figure 10 , the number of the first through holes 31 in the first end plate 30 is two, which are spaced along the second direction Y. Each first through hole 31 is provided with a first fixing member 40 to ensure the connection strength between the battery pack 1 and the electrical equipment. In other implementation manners, the number of the first through holes 31 can be three or more, and can be specifically selected according to actual usage requirements.

[0059] In some embodiments, the first fixing member 40 is a bolt.

[0060] In some embodiments, the inner diameter of the first through hole 31 is ≥ 1 cm.

[0061] In some embodiments, the inner diameter of the first through hole 31 is 2 cm to 8 cm. Thus, the first fixing member 40 can pass through the first through hole 31 and can pass out of the first through hole 31 to connect the battery pack 1 and the electrical device, and the battery pack 20 can cross the first end plate 30 along the first direction X without interfering with the first end plate 30.

[0062] In some embodiments, referring to Figures 2 to 3 、 Figures 6 to 9 and Figure 11 , the battery pack 1 further includes a side plate 60. The side plate 60 extends along the first direction X and is disposed on at least one of the opposite sides of the battery pack 20 in the second direction Y. The side plate 60 is welded to the first end plate 30. The arrangement of the side plate 60 extending along the first direction X and the welded connection between the side plate 60 and the first end plate 30 can form support and reinforcement for the battery cells 21 in the battery pack 20 arranged along the first direction X, thereby ensuring the assembly stability and firmness of the battery pack 20 inside the box body 10 and enhancing the overall strength of the battery pack 1.

[0063] In some embodiments, referring to Figure 4 and Figure 10 , along the second direction Y, at least two first positioning holes 33 are formed at one end of the first end plate 30 adjacent to the side plate 60. Referring to Figure 3 、 Figure 7 and Figure 11 , at least two second positioning holes 61 are formed on the side plate 60. The number of the first positioning holes 33 is equal to that of the second positioning holes 61. One first positioning hole 33 and one second positioning hole 61 are arranged opposite to each other along the second direction Y. Referring to Figures 2 to 4 and Figure 7 , a first welding mark 62 is formed at the welding position between the side plate 60 and the first end plate 30. The first welding mark 62 surrounds the first positioning hole 33 and the second positioning hole 61 to form a ring. Referring to Figure 3 , among the at least two second positioning holes 61, any two second positioning holes 61 respectively have a center point 611. The center point 611 has a center line 612 extending along the third direction Z. The distance between the two center lines 612 along the first direction X is L1 mm. Referring to Figure 3, the first weld mark 62 has two maximum contour points 621 oppositely arranged along the first direction X. The two maximum contour points 621 respectively have extension lines 622 extending along the third direction Z. The distance L1 mm between the two extension lines 622 along the first direction X is the maximum dimension of the first weld mark 62 in the first direction X, satisfying: L1 < L2. The setting of the first positioning hole 33 and the second positioning hole 61 can improve the accuracy of the assembly positioning between the first end plate 30 and the side plate 60. The distance L1 between the center points 611 of the two second positioning holes 61 is less than the maximum dimension L2 of the first weld mark 62 in the first direction X. This setting can not only ensure the uniform stress distribution of the first weld mark 62, but also increase the welding strength between the first end plate 30 and the side plate 60, ensure the welding stability between the first end plate 30 and the side plate 60, and ensure the stability of the battery cells 21 arranged along the first direction X in the battery pack 20, thereby ensuring the assembly stability and firmness of the battery pack 20 inside the box body 10 and enhancing the overall strength of the battery pack 1. Moreover, the first weld mark 62 surrounds the first positioning hole 33 and the second positioning hole 61, which is beneficial to reducing the stress concentration during the vibration and impact of the battery pack 20 and increasing the welding reliability between the first end plate 30 and the side plate 60.

[0064] In some embodiments, the welding method between the first end plate 30 and the side plate 60 is laser welding. The laser penetrates the side plate 60 along the second direction Y and melts part of the side wall of the first end plate 30 in the second direction Y to form the first weld mark 62.

[0065] In some embodiments, referring to Figures 2 to 4 and Figure 7 , the cross-sectional shapes of both the first positioning hole 33 and the second positioning hole 61 are circular. The second positioning hole 61 penetrates the side plate 60 along the second direction Y. The first positioning hole 33 and the second positioning hole 61 can be respectively formed by machining. The center point 611 of the second positioning hole 61 is the center of the circle of the second positioning hole 61. The center point 611 of the second positioning hole 61 can obtain the orthographic projection of the hole wall of the second positioning hole 61 on the projection plane or the shape on the tracing paper through projection or tracing, and then determine the center point 611 of the second positioning hole 61.

[0066] In some embodiments, referring to Figure 3 , the determination method of the maximum dimension L2 of the first weld mark 62 in the first direction X is as follows: After obtaining the battery pack 1, remove the battery pack 20, the first end plate 30, and the side plate 60 from the box body 10, measure the dimension of the first weld mark 62 in the first direction X with a vernier caliper, and select the maximum dimension, which is the maximum dimension L2 of the first weld mark 62 in the first direction X. Specifically, as Figures 2 to 3 and Figure 7In the illustrated embodiment, the shape of the first welding mark 62 is circular, and the maximum dimension L2 of the first welding mark 62 in the first direction X is the outer diameter of the circle.

[0067] In some embodiments, referring to Figures 7 to 8 and Figure 11 , on opposite sides of the side plate 60 in the third direction Z, it is bent towards the first surface 211 of the battery cell 21 to form a bent portion 63. The bent portion 63 is in contact with the first surface 211 and the second surface 212 respectively along the third direction Z, so that the side plate 60 forms a covering for the multiple battery cells 21 in the battery pack 20, further improving the stability of the arrangement of the battery cells 21 in the battery pack 20 along the first direction X.

[0068] In some embodiments, referring to Figures 2 to 7 , the battery pack 1 further includes a pressure strip 70. Referring to Figures 5 to 6 , the battery pack 1 further includes a second fixing member 41. Referring to Figure 4 , Figure 7 and Figure 10 , along the third direction Z, the first end plate 30 has a first end face 34 facing the second wall 12 of the box body 10. Referring to Figure 6 and Figure 10 , a second through hole 35 penetrating the first end plate 30 is formed on the first end plate 30. Referring to Figure 4 , the pressure strip 70 is arranged on the first end face 34. Referring to Figure 6 , a third through hole 71 penetrating the pressure strip 70 along the third direction Z is formed on the pressure strip 70. The third through hole 71 and the second through hole 35 are arranged opposite to each other along the third direction Z. Referring to Figure 5 and Figure 6 , the second fixing member 41 passes through the third through hole 71 and the second through hole 35 and is fixedly connected to the cross beam 50 to fix the first end plate 30 on the cross beam 50. The cooperative design of the pressure strip 70 and the second fixing member 41 can improve the connection strength between the first end plate 30 and the cross beam 50, and further improve the overall strength of the battery pack 1, ensuring the connection strength and connection stability between the battery pack 1 and the electrical equipment through the first fixing member 40.

[0069] In some embodiments, referring to Figure 7 , a fourth through hole 72 penetrating the pressure strip 70 along the third direction Z is formed on the pressure strip 70. The first fixing member 40 passes through the fourth through hole 72 along the first direction X and penetrates the second wall 12 of the box body 10 to be connected to the electrical equipment.

[0070] In some embodiments, referring to Figure 4, the second wall 12 includes a first surface 121 and a second surface 122 that are oppositely arranged along the third direction Z. The first surface 121 faces the first end plate 30 in the third direction Z. Along the third direction Z, the distance between the plane where the first end face 34 is located and the plane where the first surface 121 is located is L3 mm, the distance between the plane where the first surface 211 is located and the plane where the first surface 121 is located is L4 mm, and the distance between the plane of the side of the pressing strip 70 facing the second wall 12 and the plane where the first surface 121 is located is L5 mm, satisfying: L4 < L5 < L3. Thereby, a height difference exists between the first end face 34 of the first end plate 30 and the first surface 211 of the battery cell 21 in the third direction Z, so that a receiving space for accommodating the pressing strip 70 is formed between the plane where the first surface 211 is located and the plane where the first end face 34 is located. While ensuring the connection strength and connection stability between the pressing strip 70 and the cross beam 50, the space utilization rate of the box body 10 in the third direction Z is improved.

[0071] In some embodiments, referring to Figures 7 to 9 and Figure 12 , the battery pack 1 further includes a flexible circuit board 80. Referring to Figure 9 , the battery pack 20 includes a first battery pack 201 and a second battery pack 202 that are spaced apart along the first direction X. The first end plate 30 is disposed between the first battery pack 201 and the second battery pack 202, that is, the first end plate 30 is disposed in the battery pack 20, separating the battery pack 20 into a first battery pack 201 and a second battery pack 202 that are spaced apart along the first direction X. The first battery pack 201 and the second battery pack 202 respectively include a plurality of battery cells 21 that are spaced apart along the first direction X. Referring to Figure 7 , Figure 9 and Figure 12, the flexible circuit board 80 includes a first circuit board 81, a second circuit board 82, and a connection section 83. The first circuit board 81 and the second circuit board 82 extend along the first direction X and are spaced apart along the first direction X. The adjacent ends of the first circuit board 81 and the second circuit board 82 are connected by the connection section 83. Along the third direction Z, the first circuit board 81 is disposed on the side of the first battery pack 201 facing the second wall 12, and the second circuit board 82 is disposed on the side of the second battery pack 202 facing the second wall 12. Along the third direction Z, the connection section 83 is stacked with the first end face 34 of the first end plate 30, and the pressing strip 70 is disposed on the side of the connection section 83 facing away from the first end face 34. The structural arrangement of the first circuit board 81, the second circuit board 82, and the connection section 83 in the flexible circuit board 80 enables the first battery pack 201 and the second battery pack 202 separated by the first end plate 30 to ensure continuity along the first direction X through the flexible circuit board 80, thereby ensuring the length of the battery pack 20 in the first direction X and improving the energy density of the battery pack 1. The structural design in which the connection section 83 is stacked with the first end face 34 of the first end plate 30 along the third direction Z and the pressing strip 70 is stacked with the connection section 83 can improve the overall strength of the flexible circuit board 80 and the use stability of the battery pack 1. The connection section 83 being stacked with the first end face 34 can be that the connection section 83 is directly connected to the first end face 34, or it can be an indirect connection between the connection section 83 and the first end face 34, that is, a gasket is provided between the connection section 83 and the first end face 34.

[0072] In some embodiments, referring to Figure 7 and Figure 12 , along the third direction Z, the connection section 83 is recessed away from the second wall 12 to form a recessed portion 831 and is stacked with the first end face 34. The pressing strip 70 is embedded in the recessed portion 831. The recessed portion 831 is stacked with the first end face 34, and the pressing strip 70 is embedded in the recessed portion 831. The pressing strip 70 fixes the connection section 83 to the first end plate 30, thereby improving the assembly stability between the flexible circuit board 80, the battery pack 20, and the first end plate 30, and improving the use stability of the battery pack 1.

[0073] In some embodiments, referring to Figures 5 to 6 and Figures 8 to 9 , the battery pack 1 further includes a second end plate 90. Second end plates 90 are respectively provided at opposite ends of the battery pack 20 along the first direction X. The two second end plates 90 cooperate to form a clamping of the battery pack 20 in the first direction X, thereby improving the assembly stability and assembly strength of the battery cells 21 in the battery pack 20.

[0074] In some embodiments, referring to Figure 2 , Figure 8 and Figure 11 , along the first direction X, convex portions 64 are respectively provided at opposite ends of the side plate 60 in a protruding manner. Referring to Figure 8, a welding connection is formed between the protruding portion 64 and the adjacent second end plate 90 to form a second weld mark 65. The shape of the second weld mark 65 is linear. The design of the welding connection between the protruding portion 64 and the second end plate 90 can further improve the connection strength between the side plate 60 and the second end plate 90, thereby improving the overall strength of the battery pack 20 and the overall strength of the battery module 1.

[0075] In some embodiments, referring to Figure 9 , the battery module 1 further includes a busbar 23, an electrical isolation plate 91, and a cover plate 92. The busbar 23 is disposed on the first surface 211 of the battery cell 21. The plurality of battery cells 21 in the battery pack 20 are connected in series and / or in parallel through the busbar 23. The electrical isolation plate 91 is disposed between the flexible circuit board 80 and the battery pack 20 to prevent the flexible circuit board 80 from directly contacting the battery cell 21. The flexible circuit board 80 is electrically connected to the battery cell 21 through the busbar 23 to form an electrical circuit and collect the temperature and voltage signals of the battery cell 21. The cover plate 92 covers the surface of the flexible circuit board 80 facing away from the battery pack 20 in the third direction Z to protect the flexible circuit board 80.

[0076] In some embodiments, referring to Figure 9 , the battery module 1 further includes an insulating sheet 24. An insulating sheet 24 is disposed between two adjacent battery cells 21 along the first direction X to prevent direct contact between the two adjacent battery cells 21 and cause a short circuit.

[0077] The technical solutions provided in the embodiments of the present application have been described in detail above. Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A battery pack having a first direction (X) and a third direction (Z) intersecting each other, characterized in that: The battery pack comprises: A box body (10) is provided with a receiving cavity (101) therein, wherein the box body (10) comprises a first wall (11) and a second wall (12) which are arranged opposite to each other along the third direction (Z); A battery pack (20) is arranged in the accommodating cavity (101), the battery pack (20) comprising a plurality of battery cells (21) arranged at intervals along the first direction (X); a first end plate (30) disposed in the battery pack (20), the battery cells (21) being disposed on opposite sides of the first end plate (30) along the first direction (X), and the first end plate (30) being provided with a first through hole (31) penetrating the first end plate (30) along the third direction (Z); A first fixing member (40) is inserted into the first through hole (31), and along the third direction (Z), one of the two opposite ends of the first fixing member (40) is fixedly connected to the first wall (11), and the other end is inserted into the second wall (12) and extends to the outside of the box body (10).

2. The battery pack according to claim 1, characterized in that: The battery pack further comprises a crossbeam (50), wherein the crossbeam (50) is arranged in the accommodating cavity (101) and is fixedly connected to the first wall (11); Along the third direction (Z), the first end plate (30) and the crossbeam (50) are overlapped, and one end of the first fixing member (40) close to the crossbeam (50) is fixedly connected to the crossbeam (50).

3. The battery pack according to claim 2, characterized in that: Along the third direction (Z), a groove (32) is provided on one side of the first end plate (30) facing the cross beam (50), the cross beam (50) is embedded in the groove (32), and the first fixing member (40) is passed through the groove bottom (321) of the groove (32) and fixedly connected to the cross beam (50).

4. The battery pack according to claim 1, wherein: The battery pack further has a second direction (Y), and the first direction (X), the second direction (Y) and the third direction (Z) intersect each other; The battery pack further comprises a side plate (60), the side plate (60) extending along the first direction (X), and the side plate (60) being arranged on at least one of two opposite sides of the battery pack (20) in the second direction (Y); The side plate (60) is welded to the first end plate (30).

5. The battery pack according to claim 4, characterized in that: Along the second direction (Y), at least two first positioning holes (33) are formed on one end of the first end plate (30) adjacent to the side plate (60), and at least two second positioning holes (61) are formed on the side plate (60), the number of the first positioning holes (33) and the number of the second positioning holes (61) are equal, and one first positioning hole (33) and one second positioning hole (61) are arranged opposite to each other; The welding position of the side plate (60) and the first end plate (30) forms a first welding mark (62), and the first welding mark (62) surrounds the first positioning hole (33) and the second positioning hole (61) to form a ring shape; Among at least two of the second positioning holes (61), any two of the second positioning holes (61) respectively have a center point (611), the center point (611) has a center line (612) extending along the third direction (Z), and the distance between the two center lines (612) along the first direction (X) is L1 mm; The first weld mark (62) has two maximum contour points (621) arranged opposite to each other along the first direction (X), the two maximum contour points (621) respectively have extension lines (622) extending along the third direction (Z), and the distance L2 mm between the two extension lines (622) along the first direction (X) is the maximum size of the first weld mark (62) in the first direction (X); Satisfies: L1<L2.

6. The battery pack according to claim 2, characterized in that: The battery pack further has a second direction (Y), and the first direction (X), the second direction (Y) and the third direction (Z) intersect each other; The battery pack also includes a pressure strip (70) and a second fixing member (41); Along the third direction (Z), the first end plate (30) has a first end surface (34) facing the second wall (12), and the first end plate (30) is provided with a second through hole (35) penetrating the first end plate (30); The pressure strip (70) is arranged on the first end surface (34), and the second fixing member (41) is penetrated through the pressure strip (70) and the second through hole (35) along the third direction (Z) and is fixedly connected to the crossbeam (50) so as to fix the first end plate (30) on the crossbeam (50).

7. The battery pack according to claim 6, characterized in that: The battery cell (21) comprises a first surface (211) facing the second wall (12) along the third direction (Z), and the second wall (12) has a first surface (121) facing the first end plate (30); Along the third direction (Z), the distance between the plane where the first end surface (34) is located and the plane where the first surface (121) is located is L3 mm, the distance between the plane where the first surface (211) is located and the plane where the first surface (121) is located is L4 mm, and the distance between the plane where the side of the pressure strip (70) facing the second wall (12) is located and the plane where the first surface (121) is located is L5 mm; Satisfies: L4<L5<L3.

8. The battery pack according to claim 7, characterized in that: The battery pack further comprises a flexible circuit board (80); The battery group (20) comprises a first battery group (201) and a second battery group (202) which are arranged at intervals along the first direction (X); the first end plate (30) is arranged between the first battery group (201) and the second battery group (202); the first battery group (201) and the second battery group (202) respectively comprise a plurality of battery cells (21) which are arranged at intervals along the first direction (X); The flexible circuit board (80) comprises a first circuit board (81), a second circuit board (82) and a connecting section (83); Along the third direction (Z), the first circuit board (81) is arranged on a side of the first battery group (201) facing the second wall (12), and the second circuit board (82) is arranged on a side of the second battery group (202) facing the second wall (12); Along the first direction (X), the first circuit board (81) and the second circuit board (82) are connected at two adjacent ends via the connecting section (83); Along the third direction (Z), the connecting section (83) overlaps with the first end surface (34), the pressure strip (70) is arranged on a side of the connecting section (83) facing away from the first end surface (34), and along the second direction (Y), the connecting section (83) and the second fixing member (41) are arranged at intervals.

9. The battery pack according to claim 8, characterized in that: Along the third direction (Z), the connecting section (83) is recessed in a direction away from the second wall (12) to form a recessed portion (831) and overlaps with the first end surface (34), and the pressure strip (70) is embedded in the recessed portion (831).

10. An electrical device, characterized in that: A battery pack comprising the battery pack as claimed in any one of claims 1 to 9.

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