End plate structure for battery modularization

Abstract

An end plate structure for battery modularization is provided, which is formed by assembling a bottom plate and a top plate together. [Solution] A bottom plate (10) has a first fixed frame (12) arranged upward from the edge. The bottom plate has a first strap limiting portion (14) on its bottom surface. A top plate (20) has a second fixed frame (22) arranged downward from the edge and corresponding to the first fixed frame. The top plate has a second strap limiting portion (24) on its top surface. The second fixed portion (222) of the second fixed frame and the first fixed portion (122) of the first fixed frame are fixed to each other. The bottom plate and the top plate each have strap limiting portions whose height decreases from the center to both sides. A strap is wrapped around the first strap limiting portion of the bottom plate and the second strap limiting portion of the top plate.

Description

[Technical Field]

[0001] The present invention relates to a battery module, and more particularly to an end plate structure for battery modularization for electric vehicles. [Background technology]

[0002] Under the dual pressures of increasing environmental pollution and energy shortages, governments and major automakers around the world are increasing investments in research and development of electric vehicles. Power batteries, one of the three core components of electric vehicles - battery, motor, and electronic control - are naturally at the center of automakers' attention. With the trend toward integrating batteries into vehicle systems, cell-to-pack (CTP) technology for prismatic and cylindrical battery cells is becoming more readily available.

[0003] However, pouch battery cells lack structural strength and expand and contract during charging and discharging. To prevent battery cell expansion and increase the strength of pouch battery modules, side plates and end plates are typically required to secure the battery cells, making it difficult to separate the pouch battery from the module design.

[0004] Conventional pouch battery modules are typically constructed in a stacked configuration, with the cells within the module usually arranged vertically. To prevent cell expansion and increase the strength of the pouch battery module, side plates, end plates, and top and bottom covers are typically incorporated into the module. These side and end plates maintain the structural stability of the module by applying a certain amount of pressure to the stacked cells within the module. If the pressure is too low, the battery module may be easily damaged by vehicle vibration. If the pressure is too high, the service life of the module may be adversely affected.

[0005] Unfortunately, side plates are prone to deformation when battery cells expand. This is because the width of a battery module is typically small. To improve assembly efficiency, side plates are typically kept to a minimum thickness ranging from 1 mm to 3 mm. However, prior art designs can cause battery modules to exceed their design targets when battery cells expand, resulting in uneven force distribution on the cells and potentially affecting their service life. If the dimensions of a battery module exceed the design targets, the actual dimensions of the battery module may exceed the original design range, which can affect the overall design and assembly of the electric vehicle and even prevent the battery module from being properly installed. Deformation of the side plates can cause uneven force distribution on the battery cells within the module, accelerating battery cell degradation and ultimately leading to reduced battery performance.

[0006] Therefore, in view of the above problems in the prior art, the industry needs an end plate structure that can effectively control the pressure applied to the battery cells within a certain range so as to effectively limit the battery module to a fixed size. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to provide an end plate structure for battery modularization. A battery module is fixed between a bottom plate and a top plate. The bottom plate and the top plate have strap limiting portions that decrease in height from the center to both sides. Straps are then attached, and the convex structure of the strap limiting portions allows for uniform force distribution on the surface of the battery module. This improves the energy density and space utilization of the module, and further enhances the charge / discharge performance and lifespan of the battery module. [Means for solving the problem]

[0008] To achieve the above objectives and advantages, the present invention provides an end plate structure for battery modularization, comprising a bottom plate, a top plate, and a strap. The bottom plate comprises a first fixing frame disposed upward from its edge. The bottom plate comprises a first strap limiting portion on its bottom surface. The first strap limiting portion is recessed into the bottom surface of the bottom plate. The height of the first strap limiting portion decreases from the center toward both sides. The first fixing frame comprises a first fixing portion on its top. The top plate comprises a second fixing frame disposed downward from its edge and corresponding to the first fixing frame. The top plate comprises a second strap limiting portion on its top surface. The second fixing frame comprises a second fixing portion on its bottom. The second fixing portion corresponds to the first fixing portion, and the first and second fixing portions are fixed to each other. The strap is wrapped around the first strap limiting portion of the bottom plate and the second strap limiting portion of the top plate.

[0009] According to one embodiment of the present invention, the bottom plate includes a plurality of first fixing frames, the top plate includes a plurality of second fixing frames, the bottom plate includes a plurality of first strap limiting portions, and the top plate includes a plurality of second strap limiting portions corresponding to the plurality of first strap limiting portions of the bottom plate, and the plurality of first strap limiting portions and the plurality of first fixing frames, and / or the plurality of second strap limiting portions and the plurality of second fixing frames are alternately arranged.

[0010] According to one embodiment of the present invention, the bottom plate includes a plurality of first recesses at positions other than the first strap limiting portions.

[0011] According to one embodiment of the present invention, the top plate includes a plurality of second recesses at positions other than the second strap restraining portions.

[0012] According to one embodiment of the present invention, the first strap limiting portion and the second strap limiting portion each have a lateral width and a convex height, and the width-to-height ratio is between 2.5:1 and 400:1.

[0013] According to one embodiment of the present invention, a top plate and a bottom plate sandwich a battery module, the battery module includes a plurality of stack components, the stack components include a first battery cell, a liquid-cooled plate, and a second battery cell, and the second battery cell and the first battery cell sandwich the liquid-cooled plate.

[0014] According to one embodiment of the present invention, the battery module further includes one or more buffer members disposed between the bottom plate and the plurality of stack components, between the top plate and the plurality of stack components, or between adjacent stack components.

[0015] According to one embodiment of the present invention, the bottom plate further comprises a first extension portion on its edge, and the top plate further comprises a second extension portion on its edge, the first extension portion corresponding to the outer edge of the first strap limiting portion and extending upward from the edge of the bottom plate, the second extension portion corresponding to the outer edge of the second strap limiting portion and extending downward from the edge of the top plate, and the strap is wrapped around the first strap limiting portion and first extension portion of the bottom plate and the second strap limiting portion and second extension portion of the top plate.

[0016] According to one embodiment of the present invention, the distance between the top plate and the bottom plate is less than 150 mm, and the area of ​​the bottom surface of the top plate or the area of ​​the top surface of the bottom plate is 30,000 mm 2 Greater than.

[0017] According to one embodiment of the present invention, the second strap limiting portion is recessed on the upper surface of the top plate, and the height of the second strap limiting portion decreases from the center toward both sides relative to the bottom surface of the top plate.

[0018] According to one embodiment of the present invention, the upward extending length of the first fixing frame is greater than the downward extending length of the second fixing frame.

[0019] According to one embodiment of the present invention, the battery module further includes one or more fixing members, which pass through and fix the first fixing portion of the bottom plate and the second fixing portion of the top plate. [Brief explanation of the drawings]

[0020] [Figure 1A] FIG. 2 is an exploded view of a structure according to an embodiment of the present invention. [Figure 1B] FIG. 2 is an exploded view of a structure according to an embodiment of the present invention. [Figure 2] FIG. 2 is an assembly diagram of a structure according to an embodiment of the present invention. [Figure 3A] 1 is a cross-sectional view of a first strap limiting portion of the bottom plate in the YZ plane according to the present invention; FIG. [Figure 3B] 10 is a cross-sectional view of the second strap restraining portion of the top plate in the YZ plane according to the present invention; FIG. [Figure 3C] 10 is a partial structural view of the second strap limiting portion of the top plate according to the present invention; FIG. [Figure 4] FIG. 10 is a structural diagram of a strap limiter according to another embodiment of the present invention; [Figure 5] FIG. 1 shows a schematic diagram of a stack component according to an embodiment of the present invention. [Figure 6] 1 is a schematic diagram of a battery module and a buffer member according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0021] In view of the above-mentioned problems of the prior art, the present invention provides an end plate structure for battery modularization. First and second strap limiting portions are disposed on the bottom and top plates, respectively. Additionally, the bottom and top plates are fixed to each other by a fixed frame to sandwich the battery module. The height of one or more strap limiting portions on the bottom and top plates decreases from the center toward both sides. When straps are attached, the strap limiting portion structure can ensure uniform force distribution on the surface of the battery module. As a result, the energy density and space utilization of the module are improved, and charging (charging and discharging performance) is enhanced, thereby resolving the problem of uneven force distribution on the end plate structure for battery modularization in the prior art.

[0022] Please refer to Figures 1A and 1B. Figures 1A and 1B show exploded views of a structure according to one embodiment of the present invention. As shown in the figures, Figure 1A is an exploded top-down view of an end plate structure for battery modularization according to the present invention, and Figure 1B is an exploded bottom-up view of an end plate structure for battery modularization according to the present invention. This embodiment is a first embodiment. This embodiment provides an end plate structure 1 for battery modularization, which includes a bottom plate 10, a top plate 20, and a strap 30. A battery module 40 is disposed between the top plate 20 and the bottom plate 10.

[0023] Please refer back to FIGS. 1A and 1B and to FIG. 2. FIG. 2 shows an assembly diagram of a structure according to one embodiment of the present invention. As shown in the figure, according to this embodiment, the bottom plate 10 includes one or more first fixing frames 12 extending upward from its edge. The one or more first fixing frames 12 extend upward in a direction perpendicular to the top surface of the bottom plate 10, thereby extending upward along the sidewalls of the battery modules 40. The bottom plate 10 includes a first strap limiting portion 14 on its bottom surface opposite the top surface that supports the battery modules 40. The first strap limiting portion 14 is recessed into the bottom surface of the bottom plate 10. As shown in FIG. 3A, the height of the first strap limiting portion 14 decreases from the center toward both sides. The first fixing frame 12 includes a first fixing portion 122 at its upper portion. The top plate 20 includes a second fixing frame 22 extending downward from its edge. The second fixing frame 22 corresponds to the first fixing frame 12 and extends downward from the edge of the top plate 20. The top plate 20 has a second strap limiting portion 24 on its upper surface. The second strap limiting portion 24 is recessed into the upper surface of the top plate 20. The second fixing frame 22 has a second fixing portion 222 on its bottom. The second fixing portion 222 corresponds to the first fixing portion 122, and the two are fixed to each other. The strap 30 is wrapped around the first strap limiting portion 14 of the bottom plate 10 and the second strap limiting portion 24 of the top plate 20 (it is attached by surrounding the outside of the first strap limiting portion 14 of the bottom plate 10 and the second strap limiting portion 24 of the top plate 20, or loops around them).

[0024] According to one embodiment, the first strap limiting portion 14 is disposed on the bottom of the bottom plate 10, i.e., on a surface of the bottom plate 10 other than the surface that supports the battery module 40. The top plate 20 includes a second fixing frame 22 extending downward from the outer edge. The second strap limiting portion 24 is disposed on the top of the top plate 20, i.e., on a surface of the top plate 20 other than the surface that contacts the battery module 40. Note that the present invention is not limited to this embodiment.

[0025] According to one embodiment, the bottom plate 10 and the top plate 20 are made of metal or plastic, preferably metal. The first and second fixed frames 12 and 22 can be quickly formed by bending a metal plate. However, the present invention is not limited to this embodiment. The straps 30 may be, but are not limited to, glass fiber straps, plastic steel straps, or soft metal straps.

[0026] According to one embodiment, the distance between the top plate 20 and the bottom plate 10 is less than 150 mm. The areas of the top plate 20 and the bottom plate 10, which respectively carry the battery modules 40, i.e., the area of ​​the bottom surface of the top plate 20 and the area of ​​the upper surface of the bottom plate 10, are 30,000 mm 2 However, the present invention is not limited to this embodiment. The purpose is that if the areas of the top plate 20 and the bottom plate 10 are sufficiently large, the area (electrical capacity) of a single battery cell will also be sufficiently large, thereby reducing the number of required battery cells and decreasing the height of the battery module 40. Reducing the number of battery cells can avoid excessive expansion.

[0027] Please refer to Figures 3A to 3C. As shown in the figures, Figure 3A shows a cross-sectional view of the first strap limiting portion 14 of the bottom plate 10 in the YZ plane according to the present invention. Figure 3B shows a cross-sectional view of the second strap limiting portion 24 of the top plate 20 in the YZ plane according to the present invention. Figure 3C shows a structural diagram of a portion of the second strap limiting portion 24 of the top plate 20 in the YZ plane according to the present invention. According to this embodiment, the top surface of the bottom plate 10 is set as a reference. As shown in Figure 3A, the first strap limiting portion 14 has a first height H1 on both sides and a second height H2 in the center. The second height H2 is greater than the first height H1. Therefore, the height of the first strap limiting portion 14 gradually decreases from the center to both sides, forming a curved structure. When the strap 30 wraps around the first strap limiting portion 14, the strap 30 also forms a curve, which equalizes the force applied to the surfaces of the battery module 40 and the bottom plate 10 and prevents uneven force distribution phenomena such as point force or stress concentration. As for the height, the first height H1 can be, for example, 3 mm to 5 mm, and the second height H2 can be, correspondingly, 4 mm to 25 mm.

[0028] According to one embodiment, the bottom surface of the top plate 20 is set as a reference. As shown in FIG. 3B , the second strap limiting portion 24 has a third height H3 on both sides and a fourth height H4 in the center. The fourth height H4 is greater than the third height H3. Thus, the height of the second strap limiting portion 24 gradually decreases from the center to both sides, forming a curved structure. When the strap 30 wraps around the second strap limiting portion 24, the strap 30 also forms a curve, which equalizes the force applied to the surfaces of the battery module 40 and the top plate 20 and prevents uneven force distribution phenomena such as point force or stress concentration. Furthermore, with regard to height, the third height H3 may be, for example, 3 mm to 5 mm, and the fourth height H4 may be, correspondingly, 4 mm to 25 mm.

[0029] As shown in FIG. 3C, the first strap limiting portion 14 and the second strap limiting portion 24 each have a lateral width L1 and a convex height H5. In the figure, taking the second strap limiting portion 24 as an example, H5 = H4 - H3. The width-to-height ratio of the first strap limiting portion 14 and the second strap limiting portion 24 is between 2.5:1 and 400:1. In other words, the ratio of the lateral width L1 to the convex height H5 of the first strap limiting portion 14 is between 2.5:1 and 400:1, and the ratio of the lateral width L1 to the convex height H5 of the second strap limiting portion 24 is also between 2.5:1 and 400:1. For example, the convex height H5 is between 1 mm and 20 mm, and the lateral width L1 is between 50 mm and 400 mm.

[0030] FIG. 4 shows a schematic diagram of the structure of a strap restraint according to another embodiment of the present invention. As shown in the figure, according to one embodiment, the second strap restraint 24 is recessed into the top plate 20, and the height of the second strap restraint 24 decreases from the center toward both sides, forming a ladder (step) structure. When the strap 30 wraps around the second strap restraint 24, the strap 30 also forms a ladder structure, which equalizes the force applied to the surfaces of the battery module 40 and the top plate 20 and similarly prevents uneven force distribution phenomena such as point force or stress concentration. In addition, the ladder-shaped second strap restraint 24 is easier to manufacture.

[0031] Similarly, the height of the first strap limiting portion 14 decreases from the center to both sides, forming a ladder structure. When the straps 30 are wrapped around the first strap limiting portion 14, the straps 30 also form a ladder structure, which equalizes the force applied to the surfaces of the battery modules 40 and the bottom plate 10 and similarly prevents uneven force distribution phenomena such as point force or stress concentration. In addition, the ladder-shaped first strap limiting portion 14 is easier to manufacture.

[0032] Please refer to FIGS. 1A, 1B, and 2 again. As shown in the figures, this embodiment is a second embodiment based on the above-described first embodiment. According to this embodiment, the bottom plate 10 includes a plurality of first fixing frames 12, the top plate 20 includes a plurality of second fixing frames 22, the bottom plate 10 includes a plurality of first strap limiting portions 14, and the top plate 20 includes a plurality of second strap limiting portions 24 corresponding to the plurality of first strap limiting portions 14 of the bottom plate 10. The plurality of first strap limiting portions 14 and the plurality of first fixing frames 12, and / or the plurality of second strap limiting portions 24 and the plurality of second fixing frames 22 are alternately arranged. For example, to evenly distribute the plurality of first strap limiting portions 14, the plurality of second strap limiting portions 24, the plurality of first fixing frames 12, and the plurality of second fixing frames 22, one of the plurality of first fixing frames 12 is arranged between the plurality of first strap limiting portions 14. However, the present invention is not limited to this embodiment.

[0033] Furthermore, as shown in FIG. 1B, the bottom plate 10 may have a plurality of first recesses 16 at positions other than the first strap limiting portion 14 to reduce the weight of the bottom plate 10. As shown in FIG. 1A, the top plate 20 may have a plurality of second recesses 26 at positions other than the second strap limiting portion 24 to reduce the weight of the top plate 20. The above embodiment further includes one or more fixing members F1. The one or more fixing members F1 penetrate the first fixing portion 122 of the bottom plate 10 and the second fixing portion 222 of the top plate 20 and are used to secure the second fixing portion 222 and the first fixing portion 122 to each other. The one or more fixing members F1 may be, but are not limited to, a combination of a screw and a nut.

[0034] Please refer to FIGS. 1A, 1B, and 2 again. As shown in the figures, this embodiment is a third embodiment based on the above-described first or second embodiment. According to this embodiment, the bottom plate 10 further includes a first extension 142 at its edge. The first extension 142 corresponds to the outer edge of the first strap limiting portion 14 and extends upward from the edge of the bottom plate 10, i.e., toward the top plate 20. The top plate 20 further includes a second extension 242 at its edge. The second extension 242 corresponds to the outer edge of the second strap limiting portion 24 and extends downward from the edge of the top plate 20, i.e., toward the bottom plate 10. The strap 30 wraps around the first strap limiting portion 14 and the first extension 142 of the bottom plate 10, and the second strap limiting portion 24 and the second extension 242 of the top plate 20. The first extension 142 and the second extension 242 are used to remove sharp edges of the first strap limiting portion 14 of the bottom plate 10 and the second strap limiting portion 24 of the top plate 20, respectively. They can also prevent damage to the strap 30 due to stress concentration at the edges. The other relationships between the components in this embodiment are the same as those in the first or second embodiment described above. Therefore, detailed descriptions will be omitted.

[0035] Please refer back to FIG. 2 and refer to FIG. 5. FIG. 5 shows a schematic diagram of a stack component according to one embodiment of the present invention. As shown in the figure, according to this embodiment, a top plate 20 and a bottom plate 10 sandwich a battery module 40. The battery module 40 includes a plurality of stack components 42, each of which includes a first battery cell 422, a liquid-cooling plate 424, and a second battery cell 426. The first battery cell 422 and the second battery cell 426 sandwich the liquid-cooling plate 424 to form the plurality of stack components 42. The other relationships between the components according to this embodiment are the same as those according to the first embodiment described above. Therefore, a detailed description will be omitted.

[0036] Furthermore, the upward extension length of the first fixing frame 12 is greater than the downward extension length of the second fixing frame 22. This arrangement makes it safer and easier to sequentially stack and assemble the above-mentioned multiple stack components 42. The first fixing frame 12 can first restrain the stack components 42 near the bottom plate 10 from moving. After all of the multiple stack components 42 are arranged, it is only necessary to cover the top plate 20, so that the end plate structure 1 for battery modularization according to the present invention can provide excellent assemblability without damaging important and delicate components such as the first battery cell 422, the liquid cooling plate 424, and the second battery cell 426 during assembly.

[0037] Please refer to FIGS. 1A, 1B, 2, and 6. FIG. 6 shows a schematic diagram of a battery module and buffer members according to one embodiment of the present invention. As shown in the figure, the battery module 40 further includes one or more buffer members 50 disposed between the bottom plate 10 and the plurality of stack components 42, between the top plate 20 and the plurality of stack components 42, or between adjacent stack components 42. As shown in FIG. 2, one or more buffer members 50' can be disposed between the bottom plate 10 and the plurality of stack components 42, or one or more buffer members 50 can be disposed between the top plate 20 and the plurality of stack components 42. Alternatively, as shown in FIG. 6, one or more buffer members 50'' can be disposed between adjacent stack components 42, 42'. Other relationships between the components according to this embodiment are the same as those according to the first embodiment described above. Therefore, detailed descriptions will be omitted.

[0038] In summary, the present invention provides an end plate structure for battery modularization. The bottom plate and top plate are provided with strap limiting sections whose height decreases from the center to both sides. Straps are then attached, and the convex structure of the strap limiting sections allows for uniform force distribution on the surface of the battery module. As a result, the energy density and space utilization of the module can be improved, and the charge / discharge performance and service life of the battery module can be further enhanced. The present invention solves the problem of battery modules being unable to be installed properly when module dimensions exceed their design targets due to expansion during charge / discharge. The present invention also solves the problem of uneven force distribution on battery cells, which can accelerate battery cell degradation and even lead to reduced battery performance.

[0039] Therefore, the present invention meets legal requirements due to its novelty, non-obviousness, and practicality. However, the above description is merely an embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes or modifications made in accordance with the shape, structure, features, or spirit of the present invention are included in the scope of the appended claims of the present invention.

Claims

1. An end plate structure for battery modularization, A bottom plate, a top plate, and a strap are provided. the bottom plate includes a first fixing frame disposed upward from an edge portion, and a first strap limiting portion provided on a bottom surface, the first strap limiting portion being recessed into the bottom surface of the bottom plate, the height of the first strap limiting portion decreasing from the center toward both sides based on an upper surface of the bottom plate, and the first fixing frame includes a first fixing portion at an upper portion; the top plate is arranged downward from the edge portion, and includes a second fixing frame corresponding to the first fixing frame, and a second strap limiting portion provided on the upper surface, and a second fixing portion is provided below the second fixing frame, the second fixing portion corresponds to the first fixing portion, and the first fixing portion and the second fixing portion are fixed to each other, The strap is wrapped around the first strap limiting portion of the bottom plate and the second strap limiting portion of the top plate.

2. 2. The end plate structure of claim 1, wherein the bottom plate comprises a plurality of first fixing frames, the top plate comprises a plurality of second fixing frames, the bottom plate comprises a plurality of first strap limiting portions, the top plate comprises a plurality of second strap limiting portions corresponding to the plurality of first strap limiting portions of the bottom plate, and the plurality of first strap limiting portions and the plurality of first fixing frames, and / or the plurality of second strap limiting portions and the plurality of second fixing frames, are arranged alternately.

3. The end plate structure according to claim 1 , wherein the bottom plate has a plurality of first recesses at positions other than the first strap limiting portion.

4. The end plate structure according to claim 1 , wherein the top plate has a plurality of second recesses at positions other than the second strap limiting portion.

5. 2. The end plate structure of claim 1, wherein the first strap limiting portion and the second strap limiting portion each have a lateral width and a convex height, the ratio of the width to the height being between 2.5:1 and 400:

1.

6. 2. The end plate structure of claim 1, wherein the top plate and the bottom plate sandwich a battery module, the battery module including a plurality of stack components, the stack components including a first battery cell, a liquid-cooled plate, and a second battery cell, the second battery cell and the first battery cell sandwiching the liquid-cooled plate.

7. 7. The end plate structure according to claim 6, wherein the battery module further comprises one or more buffer members disposed between the bottom plate and the plurality of stack components, between the top plate and the plurality of stack components, or between adjacent stack components.

8. 2. The end plate structure of claim 1, wherein the bottom plate further comprises a first extension portion on its edge, the top plate further comprises a second extension portion on its edge, the first extension portion corresponding to an outer edge of the first strap limiting portion and extending upward from the edge of the bottom plate, the second extension portion corresponding to an outer edge of the second strap limiting portion and extending downward from the edge of the top plate, and the strap is wrapped around the first strap limiting portion and the first extension portion of the bottom plate and around the second strap limiting portion and the second extension portion of the top plate.

9. The distance between the top plate and the bottom plate is less than 150 mm, and the area of ​​the bottom surface of the top plate or the area of ​​the top surface of the bottom plate is 30,000 mm ２ The end plate structure of claim 1 , wherein the end plate structure is larger than the first end plate structure.

10. 2. The end plate structure according to claim 1, wherein the second strap limiting portion is recessed into the upper surface of the top plate, and the height of the second strap limiting portion decreases from the center toward both sides with respect to the bottom surface of the top plate.

11. 2. The end plate structure according to claim 1, wherein the length of the first fixing frame extending upward is greater than the length of the second fixing frame extending downward.

12. 7. The end plate structure of claim 6, wherein the battery module further comprises one or more fixing members, the one or more fixing members penetrating and fixing the first fixing portion of the bottom plate and the second fixing portion of the top plate.

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