Battery pack

Abstract

The utility model provides a battery pack. The battery pack comprises a top cover; the box body is matched with the top cover and comprises side beams and a bottom plate; the battery cell stacking body is arranged in the box body; the end plate is arranged between the battery cell stacking body and the side beam, one side, in the thickness direction, of the end plate abuts against the side beam, the other side of the end plate abuts against the battery cell stacking body, and a containing cavity is formed in the end plate; and at least one part of the busbar passes through the accommodating cavity and extends along the length direction of the end plate. The battery pack provided by the utility model is simple in structure, convenient to manufacture, high in strength of the end plates, good in stability and long in service life, and avoids local fracture, and the busbar can be effectively protected.

Description

TECHNICAL FIELD

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

[0002] With the continuous development of new energy vehicles, power batteries are gradually developing towards high energy density and high volume utilization rate. The battery pack is a whole unit assembled by multiple battery modules, used for storing and providing electric energy. When designing the internal structure of the battery pack, the space occupancy rate of the battery cell gradually increases, and the space left for other structural parts becomes less and less. Under the condition of meeting the structural strength, reasonable arrangement of key structural parts becomes a big challenge for the design of the battery pack.

[0003] CTP (Cell To Pack, module-free power battery pack) is a technology that directly assembles battery cells into a battery pack, which saves the traditional module design, thereby improving the space utilization rate of the battery pack and reducing the volume and weight. In order to further reduce the weight of the CTP battery pack and save the internal space, the end plate in the battery pack is generally set as a plastic part and directly cooperates with the battery pack frame, but it is found that the end plate is prone to local fracture during use. Therefore, there is an urgent need for a battery pack with stronger structural stability. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the purpose of the present application is to provide a battery pack to solve the problems mentioned in the background art.

[0005] The present application provides a battery pack, comprising: a top cover; a box body cooperating with the top cover, comprising a side beam and a bottom plate; a battery cell stack provided in the box body; an end plate provided between the battery cell stack and the side beam, one side of the end plate along the thickness direction abuts against the side beam, and the other side abuts against the battery cell stack, and the inside of the end plate is provided with a receiving cavity; and a busbar, at least a part of the busbar passes through the receiving cavity and extends along the length direction of the end plate.

[0006] Further, the busbar comprises a flexible circuit board or a busbar.

[0007] Further, the busbar is a flexible circuit board, and the busbar is integrally formed with the end plate.

[0008] Further, at least one side of the receiving cavity along the height direction is provided with an opening, the busbar is arranged in the receiving cavity through the opening, and the height direction is perpendicular to the bottom plate.

[0009] Further, in the cross section of the end plate along the thickness direction, the busbar is arranged parallel to the height direction of the end plate, and the busbar is located at the end of the end plate away from the bottom plate in the height direction.

[0010] Further, the distance between the busbar and the side of the end plate along the thickness direction is a first distance, and the first distance is greater than or equal to 1 / 4 of the thickness of the end plate; and / or, the distance between the busbar and the side of the end plate along the height direction is a second distance, and the second distance is greater than or equal to 1 / 2 of the height of the busbar.

[0011] Further, a limiting block is arranged at the notch of the opening, and the limiting block is used to limit the position of the busbar.

[0012] Further, the end of the busbar is bonded to the side wall of the accommodating cavity along the thickness direction.

[0013] Further, the busbar comprises a straight section, at least one end of the straight section is provided with a bending redundancy section, the bending redundancy section is located in the accommodating cavity, and the length of the bending redundancy section is greater than or equal to 1 / 10 of the length of the end plate.

[0014] Further, the end of the busbar is provided with an electrical interface, and the electrical interface is located in the accommodating cavity and is used to electrically connect with the battery cell stack.

[0015] As can be seen from the above, the battery pack provided by the application comprises a top cover, a box body cooperating with the top cover and comprising a side beam and a bottom plate, a battery cell stack arranged in the box body, an end plate arranged between the battery cell stack and the side beam, the side of the end plate along the thickness direction abutting against the side beam, and the other side abutting against the battery cell stack, the inside of the end plate being provided with an accommodating cavity, and a busbar, at least a part of the busbar penetrating through the accommodating cavity and extending along the length direction of the end plate. By penetrating at least a part of the busbar through the accommodating cavity of the end plate and extending along the length direction of the end plate, the side of the end plate along the thickness direction does not need to be provided with a avoiding space any more, and can be completely attached to the side beam of the battery pack, thereby reducing the deformation of the end plate caused by the expansion of the battery cell and avoiding the breakage of the end plate causing the failure of the busbar; the busbar is located in the inside of the accommodating cavity, has high integration degree, can ensure the space utilization rate, and can also play a protection role. The battery pack has simple structure, is convenient to manufacture, has high strength of the end plate, avoids the local breakage, can effectively protect the busbar, has good stability, and has long service life. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the application or related art, the drawings needed to be used in the embodiments or related art descriptions will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0017] Figure 1It is a schematic diagram of a partial cross section of a battery pack in the related art;

[0018] Figure 2 It is a schematic diagram of an explosion structure of a battery pack in the embodiment of the present application;

[0019] Figure 3 It is a schematic diagram of a partial cross section of a battery pack in the embodiment of the present application;

[0020] Figure 4 It is Figure 3 It is a schematic diagram of a partial solid structure of the inside of an end plate of a battery pack;

[0021] Figure 5 It is a schematic diagram of a partial cross section of another battery pack in the embodiment of the present application;

[0022] Figure 6 It is Figure 5 It is a schematic diagram of a partial solid structure of the inside of an end plate of a battery pack.

[0023] The reference signs: 1, end plate; 1-1, opening; 1-2, limiting block; 1-3, accommodating cavity; 1-4, avoiding space; 2, female busbar; 2-1, straight section; 2-2, bending redundant section; 3, top cover; 4, box body; 4-1, side beam; 4-2, bottom plate; 5, electric core stack. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below with reference to the embodiments and the accompanying drawings.

[0025] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be understood as the general meaning understood by those skilled in the art to which the embodiments of the present application belong. The terms “first”, “second” and similar terms used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. The terms “include” or “contain” and similar terms mean that the elements or objects before the terms cover the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms “connect” or “connected” and similar terms are not limited to physical or mechanical connection, but can include electrical connection, whether direct or indirect. The terms “up”, “down”, “left”, “right” and the like only represent relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0026] CTP battery pack is a technology of directly assembling battery cells into a battery pack, which saves the traditional module design, thereby improving the space utilization and reducing the volume and weight of the battery pack. In order to further reduce the weight of the CTP battery pack and save the internal space, the end plate clamping the cell stack in the battery pack is generally made of plastic, and the end plate is directly matched with the battery pack frame. However, it is found in use that the end plate is prone to local fracture.

[0027] As shown in Figure 1 , it is a partial cross-sectional view of a battery pack, one side of the end plate 1 abuts against the cell stack 5, and the other side abuts against part of the side beam 4-1 of the box body 4. Because the busbar 2 needs to be avoided, the avoidance space 1-4 is arranged on the end plate 1, which causes a certain gap between the local area of the end plate 1 and the side beam 4-1. Under the cell expansion working condition, the avoidance space 1-4 is squeezed, causing stress concentration in the local area of the end plate 1, so that the end plate 1 is prone to fracture. The fracture of the end plate 1 will cause the risk of short circuit of the busbar 2 or other structural parts.

[0028] In addition, because the end plate 1 reserves the avoidance space 1-4, the space utilization inside the battery pack is also reduced. If the setting position of the busbar 2 is adjusted in a large range, the busbar 2 is also prone to be integrated with the glue filling of the battery pack, and the busbar 2 cannot be replaced and repaired after failure; or the busbar 2 directly contacts with the metal part, causing short circuit or wear failure, etc.

[0029] Hereinafter, the technical solutions of the present application will be further described in detail through specific embodiments and in combination with the accompanying Figures 2 to 6 drawings.

[0030] In some embodiments of the present application, a battery pack is provided, which comprises: a top cover 3; a box body 4 matched with the top cover 3, comprising a side beam 4-1 and a bottom plate 4-2; a cell stack 5 arranged in the box body 4; an end plate 1 arranged between the cell stack 4 and the side beam 4-1, one side of the end plate 1 abuts against the side beam 4-1 along the thickness direction, and the other side abuts against the cell stack 5, and the inside of the end plate 1 is provided with a receiving cavity 1-3; and a busbar 2, at least a part of the busbar 2 passes through the receiving cavity 1-3 and extends along the length direction of the end plate 1.

[0031] As shown in Figure 2 , it is an exploded structural view of a battery pack, which comprises a top cover 3 and a box body 4, and the box body 4 is provided with a plurality of cell stacks 5, each of which comprises a plurality of stacked battery cells, and each of the cell stacks 5 is provided with an end plate 1 on both sides of the large face. The material of the end plate 1 is plastic, which can reduce the weight of the battery pack while ensuring the strength.

[0032] As shown in Figure 3 , it is a partial cross-sectional view of a battery pack, which comprises a top cover 3 and a box body 4, and the box body 4 is provided with a plurality of cell stacks 5, each of which comprises a plurality of stacked battery cells, and each of the cell stacks 5 is provided with an end plate 1 on both sides of the large face. The material of the end plate 1 is plastic, which can reduce the weight of the battery pack while ensuring the strength. Figure 2A partial cross-sectional diagram of the battery pack is shown, where T represents the thickness direction of end plate 1 and H represents the height direction of end plate 1. The housing 4 includes mutually perpendicular side beams 4-1 and a bottom plate 4-2. End plate 1 is positioned between the cell stack 4 and the side beams 4-1. One side of end plate 1 abuts against the side beams 4-1 along its thickness direction, and the other side abuts against the cell stack 5, thus clamping and protecting the cells.

[0033] like Figure 4 As shown, Figure 3 The diagram shows the internal structure of the end plate 1, where L represents the length of the end plate 1. The end plate 1 has internal cavities 1-3 to reduce its weight. The battery pack also includes a busbar 2, which may include a flexible printed circuit (FPC) or a busbar (copper busbar) for connecting battery cells or other components. By extending at least a portion of the busbar 2 through the cavities 1-3 of the end plate 1 along its length, the side of the end plate 1 along its thickness direction no longer requires clearance space and can fully fit against the side beam 4-1. This increases the stiffness of the end plate 1 along the direction of battery cell expansion, thereby reducing deformation of the end plate 1 caused by battery cell expansion and preventing the busbar 2 from failing due to breakage of the end plate 1.

[0034] Busbar 2 is located inside the housing cavity 1-3, preventing failure of other metal components connected to busbar 2. End plate 1 also constrains busbar 2, preventing severe deformation caused by vibration or impact. Busbar 2 extends along the length of end plate 1, exhibiting a high degree of integration and improving the space utilization of the battery pack.

[0035] The battery pack has a simple structure and is easy to manufacture. The end plate 1 has high strength, which avoids local breakage and can also effectively protect the busbar 2. The battery pack has good stability and long service life.

[0036] In some embodiments, the busbar 2 is a flexible circuit board, and the busbar 2 and the end plate 1 are integrally formed.

[0037] like Figure 3 As shown, busbar 2 is a flexible circuit board, and end plate 1 and busbar 2 are integrally injection molded. During the manufacturing process, busbar 2 can be placed in the mold of end plate 1 and fixed before injection molding, and the specific process is not limited. The integral molding of busbar 2 and end plate 1 can ensure the integrity of the outer contour of end plate 1. During the expansion of the battery cell, end plate 1 is subjected to more uniform stress. End plate 1 has a high degree of integration, higher space utilization, and reduces battery packaging and assembly processes.

[0038] like Figure 4 As shown, because the end plate 1 is in close contact with the busbar 2, it can effectively constrain the busbar 2, and can avoid short circuits or failures caused by friction between components during battery pack impact or vibration.

[0039] In some embodiments, the accommodating cavity 1-3 is provided with an opening 1-1 on at least one side in the height direction, and the busbar 2 is arranged in the accommodating cavity 1-3 through the opening 1-1, and the height direction is perpendicular to the bottom plate 4-2.

[0040] As shown in FIG. 1, it is a schematic view of a partial cross section of another battery pack, the accommodating cavity 1-3 is provided with an opening 1-1 on at least one side in the height direction, and the busbar 2 is arranged in the accommodating cavity 1-3 through the opening 1-1, and because the busbar 2 and the end plate 1 are not designed in one piece, the busbar 2 can be detachably installed, which is convenient for replacement and maintenance of the busbar 2 after failure, and an electrical interface can not be arranged at the end of the busbar 2, which can be adjusted according to the actual connection requirement. Figure 5 In some embodiments, in the cross section of the end plate 1 in the thickness direction, the busbar 2 is arranged parallel to the height direction of the end plate 1, and the busbar 2 is located at the end of the end plate 1 away from the bottom plate 4-2 in the height direction.

[0041] As shown in FIG. 1, the busbar 2 is arranged at the end of the end plate 1 away from the bottom plate 4-2, which can avoid adhesion of the busbar 2 with the battery pack bottom glue pouring, and the busbar 2 cannot be replaced and repaired after failure.

[0042] Figure 3 As shown in FIG. 1, the opening 1-1 is arranged on the side of the accommodating cavity 1-3 away from the bottom plate 4-2, which can facilitate replacement of the busbar 2 and also avoid the busbar 2 from sliding out of the accommodating cavity 1-3.

[0043] As shown in FIG. 1, the opening 1-1 is arranged on the side of the accommodating cavity 1-3 away from the bottom plate 4-2, which can facilitate replacement of the busbar 2 and also avoid the busbar 2 from sliding out of the accommodating cavity 1-3. Figure 5 In some embodiments, the distance between the busbar 2 and the side of the end plate 1 in the thickness direction is a first distance, and the first distance is greater than or equal to 1 / 4 of the thickness of the end plate 1; and / or, the distance between the busbar 2 and the side of the end plate 1 in the height direction is a second distance, and the second distance is greater than or equal to 1 / 2 of the height of the busbar 2.

[0044] As shown in FIG. 1, D1 is the distance between the busbar 2 and the side of the end plate 1 in the thickness direction, i.e. the first distance, and the thickness of the end plate 1 is for example T1, and D1 can be 1 / 4T1, 1 / 3T1 or 2 / 5T1, etc., which is not limited in particular. Setting D1≥1 / 4T1 has good protection effect on the busbar 2, which avoids the busbar 2 from being too close to the side of the end plate 1, and the busbar 2 is severely deformed when the battery cell is expanded, which leads to failure of the busbar 2.

[0045] Figure 5 As shown in FIG. 1, D1 is the distance between the busbar 2 and the side of the end plate 1 in the thickness direction, i.e. the first distance, and the thickness of the end plate 1 is for example T1, and D1 can be 1 / 4T1, 1 / 3T1 or 2 / 5T1, etc., which is not limited in particular. Setting D1≥1 / 4T1 has good protection effect on the busbar 2, which avoids the busbar 2 from being too close to the side of the end plate 1, and the busbar 2 is severely deformed when the battery cell is expanded, which leads to failure of the busbar 2.

[0046] As shown in FIG. 1, D1 is the distance between the busbar 2 and the side of the end plate 1 in the thickness direction, i.e. the first distance, and the thickness of the end plate 1 is for example T1, and D1 can be 1 / 4T1, 1 / 3T1 or 2 / 5T1, etc., which is not limited in particular. Setting D1≥1 / 4T1 has good protection effect on the busbar 2, which avoids the busbar 2 from being too close to the side of the end plate 1, and the busbar 2 is severely deformed when the battery cell is expanded, which leads to failure of the busbar 2. Figure 5 ​​As shown, D2 is the distance between the busbar 2 and the end plate 1 along the height direction of one side, that is, the second distance. For example, the height of the busbar 2 is H1, and D2 can be 1 / 2H1, 2 / 3H1, or H1, and the like, and the specific value is not limited. By setting D2≥1 / 2H1, the protection effect of the busbar 2 is good, and the busbar 2 is prevented from being too close to the top surface or the bottom surface of the end plate 1, which is easy to contact or wear with other components, resulting in short circuit or failure of the busbar 2.

[0047] In some embodiments, a limiting block 1-2 is arranged at the notch of the opening 1-1, and the limiting block 1-2 is used to limit the position of the busbar 2.

[0048] As shown, it is an internal structure diagram of the end plate 1. One or more protruding limiting blocks 1-2 can be arranged at the opening 1-1 to limit the position of the busbar 2, ensure the stability of the busbar 2, and prevent the busbar 2 from falling off the accommodating cavity 1-3. Figure 6 Figure 5 As shown, it is an internal structure diagram of the end plate 1. One or more protruding limiting blocks 1-2 can be arranged at the opening 1-1 to limit the position of the busbar 2, ensure the stability of the busbar 2, and prevent the busbar 2 from falling off the accommodating cavity 1-3.

[0049] In some embodiments, as shown, the end of the busbar 2 is bonded to the side wall of the accommodating cavity 1-3 in the thickness direction, further fixing the busbar 2. Figure 4 In some embodiments, the busbar 2 includes a straight section 2-1, and at least one end of the straight section 2-1 is provided with a bending redundancy section 2-2. The bending redundancy section 2-2 is located in the accommodating cavity 1-3, and the length of the bending redundancy section 2-2 is greater than or equal to 1 / 10 of the length of the end plate 1.

[0050] As shown, the busbar 2 includes a straight section 2-1, and one end or both ends of the straight section 2-1 can be provided with a bending redundancy section 2-2. During the use of the battery pack, the busbar 2 will be subjected to extrusion. By arranging the bending redundancy section 2-2, the deformation amount of the busbar 2 can be provided, and the damage of the busbar 2 can be avoided.

[0051] Figure 6 The bending redundancy section 2-2 is arranged in the accommodating cavity 1-3, which can improve the space utilization. For the design of the busbar 2 and the end plate 1 being integrally formed, the accommodating cavity 1-3 can provide a deformation space for the busbar 2.

[0052] The length of the bending redundancy section 2-2 is, for example, L1, and the length of the end plate 1 is, for example, L2. L1 can be 1 / 10L2, 1 / 9L2, or 1 / 8L2, and the like, and the specific value is not limited. By setting L1≥1 / 10L2, the busbar 2 is protected, and the bending redundancy section 2-2 is prevented from being too short and unable to provide sufficient extrusion deformation demand.

[0053] In some embodiments, the end of the busbar 2 is provided with an electrical interface, and the electrical interface is located in the accommodating cavity 1-3 and is used to be electrically connected with the cell stack 5.

[0054] In some embodiments, the end of the busbar 2 is provided with an electrical interface, and the electrical interface is located in the accommodating cavity 1-3 and is used to be electrically connected with the cell stack 5.

[0055] ​​When the busbar 2 is a flexible circuit board, an electrical interface can be arranged at the end portion for electrical connection with the cell stack 5. For the design in which the busbar 2 is integrally formed with the end plate 1, the electrical interface can be arranged in the accommodating cavity 1-3, facilitating connection.

[0056] The battery pack can be applied to an electrical device, which can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, and an electric planer, etc.

[0057] It should be understood by those of ordinary skill in the art that the above discussion of any of the embodiments is merely exemplary and is not intended to suggest the scope of the application (including the claims) is limited to these examples; the embodiments or technical features among different embodiments can be combined, and the steps can be implemented in any order, and there are many other changes to the aspects of the embodiments of the application as described above, which are not provided in detail for the sake of brevity. It should be understood that the above description is illustrative and not restrictive.

[0058] In addition, although the details have been described to describe the exemplary embodiments of the application, it is obvious to those skilled in the art that the embodiments of the application can be implemented without these details or with changes to these details. Therefore, these descriptions should be considered as illustrative rather than limiting.

[0059] Although the application has been described in conjunction with the embodiments thereof, many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description.

[0060] The embodiments of the application are intended to cover all such alternatives, modifications, and variations as falling within the broad scope of the appended claims. Accordingly, any one of the above-described embodiments of the application can be further modified through various combinations to fall within the scope of the application. Accordingly, the application is not limited to the above-described embodiments.

Claims

1. A battery pack, characterized in that, include: Top cover; The housing, which mates with the top cover, includes side beams and a bottom plate; A cell stack is disposed inside the housing; An end plate is disposed between the cell stack and the side beam. One side of the end plate abuts against the side beam along the thickness direction, and the other side abuts against the cell stack. The end plate has a receiving cavity inside. A busbar, at least a portion of which passes through the receiving cavity and extends along the length of the end plate.

2. The battery pack according to claim 1, characterized in that, The busbar includes a flexible circuit board or a busbar.

3. The battery pack according to claim 1, characterized in that, The busbar is a flexible circuit board, and the busbar and the end plate are integrally formed.

4. The battery pack according to claim 1, characterized in that, The receiving cavity has an opening on at least one side along the height direction, and the busbar is disposed in the receiving cavity through the opening, the height direction being perpendicular to the base plate.

5. The battery pack according to claim 3 or 4, characterized in that, In the cross-section of the end plate in the thickness direction, the busbar is arranged parallel to the height direction of the end plate, and the busbar is located at the end of the end plate that is away from the bottom plate in the height direction.

6. The battery pack according to claim 3 or 4, characterized in that, The distance between the busbar and one side of the end plate along the thickness direction is a first distance, which is greater than or equal to 1 / 4 of the thickness of the end plate; and / or, the distance between the busbar and one side of the end plate along the height direction is a second distance, which is greater than or equal to 1 / 2 of the height of the busbar.

7. The battery pack according to claim 4, characterized in that, A limiting block is provided at the slot of the opening, and the limiting block is used to restrict the position of the busbar.

8. The battery pack according to claim 1, characterized in that, The end of the busbar is bonded to the side wall of the receiving cavity along the thickness direction.

9. The battery pack according to claim 1, characterized in that, The busbar includes a straight section, and at least one end of the straight section is provided with a bent redundant section. The bent redundant section is located within the receiving cavity, and the length of the bent redundant section is greater than or equal to 1 / 10 of the length of the end plate.

10. The battery pack according to claim 1, characterized in that, The end of the busbar is provided with an electrical interface, which is located inside the receiving cavity and is used to electrically connect to the battery cell stack.

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