Lithium battery module end plate with novel structure

Abstract

The utility model relates to the technical field of lithium batteries in the new energy industry, in particular to a lithium battery module end plate with a new structure, which comprises an end plate back plate, a reinforcing plate and a square nut, the inner side of the end plate back plate is connected with the two reinforcing plates, the end plate back plate is provided with a positioning convex hull, the end plate and the reinforcing plates can be rapidly and accurately connected, module mounting holes are formed in the bottom, nut standard parts are connected to the upper portion, the end plate back plate and the reinforcing plates are integrally completed through die stamping, the consistency of the product state and the strength are high, and meanwhile the product quality is improved. The end plate is simple in structure and relatively convenient to combine, and the end plate and the module are relatively convenient to install. According to the utility model, an original traditional metal plate tailor-welded structure and an aluminum magnesium alloy structure are replaced, under the condition that enough mechanical strength is ensured, compared with the tailor-welded metal plate structure, the weight and the product price cost of the battery module can be effectively reduced, and compared with aluminum and magnesium alloy, the cost is greatly reduced.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, specifically to a novel structured lithium battery module end plate. Background Technology

[0002] With the continuous development of the national transformation of old and new growth drivers and the increasing environmental awareness of the people, more and more electronic devices are choosing lithium batteries as their main power source, such as mobile phones and electric vehicles (electric buses, electric coaches, etc.). Especially in recent years, the strong trend of increasing use of new energy vehicles has undoubtedly provided a broader space for the application and development of lithium batteries. Among them, the lithium batteries commonly used in new energy electric vehicles are generally referred to as power batteries.

[0003] In the application of power batteries for new energy vehicles, what we observe externally is the outer casing of the lithium battery or the battery pack shell. Inside the lithium battery casing, one or more individual cells (lithium batteries) are usually combined into a battery module by connecting them in series or parallel. The battery module is used for overall output. Therefore, the design of the battery module is very important.

[0004] Currently, the end plate structure of battery modules in the industry consists of plastic, aluminum alloy, magnesium alloy, and sheet metal welded structure. However, due to the large expansion force of batteries after use, plastic structures are almost never used in the end plate of modules in the field of new energy vehicles. The other three structural forms are mostly adopted to ensure the rigidity of the end plate.

[0005] Each of the three types of end plates has its own shortcomings during use:

[0006] 1. The relatively high cost of metals such as aluminum alloys and magnesium alloys undoubtedly increases production costs when mass-producing battery modules.

[0007] 2. Sheet metal welding structure. The product manufacturing process involves many processes and a large number of parts. The production process often adopts laser cutting-multiple bending-secondary blasting (or laser)-piercing-welding method. The longitudinal expansion force generated by the battery module during operation causes most of the expansion force to act directly on the weld between the end plate and the side plate. When the expansion force exceeds the connection strength of the weld, the weld will be damaged, ultimately causing the battery module to fail. Utility Model Content

[0008] This utility model provides a novel end plate structure for lithium battery modules, addressing the shortcomings and high costs of existing technologies. While still a sheet metal structure, this end plate differs in that the welding structure is replaced with a stamping structure, and the thickness of the original welded sheet metal material is reduced from 1.5mm or 1.2mm to 1.0mm. This effectively reduces the weight of the battery module compared to welded sheet metal structures while maintaining sufficient mechanical strength. Furthermore, the product cost is significantly lower compared to aluminum and magnesium alloys.

[0009] The present invention solves the above-mentioned technical problems through the following technical solution:

[0010] A novel lithium battery module end plate, the end plate being used to cover one end of a battery cell structure, the end plate comprising:

[0011] End plate and back plate; used to support the cell structure, the bottom of the end plate and back plate is provided with a positioning protrusion.

[0012] A reinforcing plate is welded and fixed to the back plate of the end plate, and the reinforcing plate is provided with positioning holes corresponding to the positioning protrusions.

[0013] In one specific embodiment, the end plate back plate is surrounded by its four edges, the inner side of the end plate back plate is welded to two reinforcing plates, and the surrounding surface is welded to three welding square nuts.

[0014] In a specific embodiment, the end plate back plate and the reinforcing plate are both integrally stamped structures; a U-shaped notch is provided between the four enclosing surfaces of the end plate back plate.

[0015] In one specific embodiment, the reinforcing plate includes at least one U-shaped bending structure, with an extension plate perpendicular to the U-shaped bend on one side of the U-shaped bending structure, and the other side of the force-bearing surface overlapping one side of the end plate back plate.

[0016] In a specific embodiment, the reinforcing plate includes two U-shaped bending structures, with a connecting surface perpendicular to the U-shaped bend between the two U-shaped bending structures. The connecting surface is provided with positioning holes corresponding to the positioning protrusions. One of the U-shaped bending structures overlaps one side of the end plate back plate, and the other U-shaped bending structure has an extension plate perpendicular to the U-shaped bend on its inner side.

[0017] In one specific embodiment, the reinforcing plate is provided with a plurality of limiting protrusions.

[0018] In a specific embodiment, the end plate back plate is provided with two reinforcing plates, which are symmetrically arranged and positioned and welded to the positioning holes by positioning protrusions; the edge of the end plate back plate overlaps with the stress-bearing surface of the reinforcing plate.

[0019] The beneficial effects of this utility model are as follows: 1. In this new structure end plate, the back plate itself has a convex bulge structure, which can solve the problem of assembly error caused by the lack of positioning tooling between the back plate and the reinforcing plate to the greatest extent, effectively ensuring the rapid assembly of the end plate, back plate and reinforcing plate, improving the battery module and improving the assembly efficiency.

[0020] 2. The main material of the end plate back plate is a thin metal sheet. It is welded using spot welding. Compared with the welding process in the sheet metal structure, it reduces the amount of welding deformation while meeting the same strength requirements of the end plate structure. This ensures the dimensional requirements of the new end plate structure and reduces the processing work of the product after MIG welding or laser welding.

[0021] 3. During module assembly and bundling, in order to ensure the tightness of each module, special assembly equipment is used to bundle and assemble both ends. The cable ties will generate a tension force of more than 600N. In order to prevent the end plate from deforming due to the tension force, a local structural reinforcement design is carried out in the new structural end plate of the new design invention. The edge of the end plate back plate overlaps with the stress surface of the reinforcement plate. Compared with the reinforcement plate, a stiffener plate is added to support it, thereby ensuring the tensile strength of the end plate. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 The diagram shows the structural forms of end plates made of aluminum alloy and magnesium alloy materials in the prior art;

[0024] Figure 2 The diagram shown is a structural form of the end plate of the sheet metal welding structure in the prior art;

[0025] Figure 3 The diagram shown is a schematic representation of the structure of this utility model.

[0026] Figure 4 The diagram shown is an exploded view of the structure of this utility model;

[0027] Figure 5 The diagram shown is a welded assembly diagram of the structure of this utility model;

[0028] Figure 6 The diagram shows the installation effect of the module.

[0029] Figure 7 The diagram shows a limiting convex bulge of the end plate structure.

[0030] Figure 8 The diagram shown is a partial structural schematic of this utility model.

[0031] In the attached diagram: 1-End plate back plate; 2-Reinforcing plate; 3-Square nut; 4 / 5-Protrusion; 6 / 7-Positioning hole; 8-U-shaped bending structure; 9-Force-bearing surface; 10-Extended plate; 11-Limiting protrusion; 12-Oblong hole. Detailed Implementation

[0032] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0033] Example 1

[0034] This utility model provides a novel structural end plate. Figure 4 The end plate back plate 1 and two reinforcing plates 2 are welded together using automotive body spot welding technology. Figure 5 );

[0035] The end plate back plate 1 is surrounded by its four edges. The inner side of the end plate back plate 1 is welded to two reinforcing plates 2, and the surrounding surface is welded to three welding square nuts 3. In the design structure, two circular protrusions 4 / 5 are designed on the left and right ends of the end plate back plate 1, and two holes are designed on the reinforcing plate as positioning holes 6 / 7, corresponding to the protrusions of the back plate. During welding, the protrusions and holes are quickly positioned, and the back plate and reinforcing plate 2 are quickly attached and spot welded to form a new end plate welded structure.

[0036] The end plate back plate 1 includes, but is not limited to, two reinforcing plates 2, and the presence of two reinforcing plates 2 is an optimized structure (e.g., Figure 4 , 5 Two reinforcing plates 2 are symmetrically arranged and are positioned and welded to the positioning holes 6 / 7 through positioning protrusions 4 / 5; the edge of the end plate back plate 1 overlaps with the stress-bearing surface 9 of the reinforcing plate.

[0037] The reinforcing plate 2 includes at least one U-shaped bending structure 8, with an extension plate 10 perpendicular to the U-shaped bend on one side of the U-shaped bending structure 8, and the force-bearing surface 9 on the other side overlapping one side of the end plate back plate 1. This is a single U-shaped bending structure 8.

[0038] exist Figure 4 , 5The optimized structure is that the reinforcing plate 2 includes two U-shaped bending structures 8, and the extended plate 10 and the stress-bearing surface 9 are respectively placed on one side of the two U-shaped bending structures 8. As the number of U-shaped bending structures 8 increases, the support strength of the end plate back plate 1 is greater.

[0039] The main material of the end plate is a thin metal sheet. It is welded using spot welding. Compared with the welding process in the sheet metal structure, it reduces the amount of welding deformation while meeting the same strength requirements of the end plate structure. This ensures the dimensional requirements of the new end plate structure and reduces the processing work of the product after MIG welding or laser welding.

[0040] During module assembly, multiple battery cells are connected in series, and an end plate is used at each end for binding and bonding. After assembly, they form a module. Figure 6 To prevent instability in the cable ties, multiple limiting protrusions 11 are designed on the reinforcing plate 2 for limiting the cable ties. Their limiting effect achieves the same effect as the slotted aluminum alloy type and the piercing limiting effect of the welded sheet metal structure. These protrusions ( Figure 7 It adopts a stamping process, but compared with other structural forms of end plates, it reduces the cutting and processing process after forming, thus reducing the product production cost.

[0041] During module assembly and bundling, in order to ensure that each module ( Figure 6 To ensure the tightness of the end plate, special assembly equipment is used to bundle and assemble both ends. The cable ties will generate a tension force of more than 600N. In order to prevent the end plate from deforming due to the tension force, a local structural reinforcement design is carried out in the new structure end plate. The edge of the end plate back plate 1 is overlapped with the stress surface 9 of the reinforcement plate. Compared with the reinforcement plate 2, a stiffener is added to support it, thereby ensuring the tensile strength of the end plate.

[0042] This structure functions as a support rib without adding any new components. It is supported by the end plate and back plate themselves, meeting the tensile strength requirements for stress deformation of the end plate. Compared with the current traditional sheet metal welding structure, it reduces the need for MIG welding to reinforce the end plate, thus reducing welds and lowering product production costs.

[0043] Among commonly used battery cells, those with similar dimensions to other products all exhibit certain processing errors within the standard range. When these cells are stacked and assembled, the accumulated errors lead to an assembly error in the overall module size, making it impossible to guarantee 100% consistency in the dimensions of each module. To facilitate the installation of the module and the housing structure, the mounting holes for the connection between the end plate and the housing in the new structural end plate design utilize a 12mm elongated hole design. Figure 8 This can absorb the dimensional errors in module assembly.

[0044] The above embodiments illustrate in detail the structural composition and working principle of a novel lithium battery module end plate of the present invention, providing detailed technical basis and implementation methods for practical applications. These embodiments are not intended to limit the present invention; those skilled in the art can make appropriate modifications or substitutions without departing from the spirit of the present invention to achieve the same technical effects.

[0045] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A novel lithium battery module end plate, wherein the module end plate is used to cover one end of a battery cell structure, characterized in that, The module end plate includes: End plate and back plate; used to support the cell structure, the bottom of the end plate and back plate is provided with a positioning protrusion. A reinforcing plate is welded and fixed to the back plate of the end plate, and the reinforcing plate is provided with positioning holes corresponding to the positioning protrusions.

2. The module end plate according to claim 1, characterized in that, The end plate back plate is surrounded by its four edges. The inner side of the end plate back plate is welded to two reinforcing plates, and the surrounding surface is welded to three square nuts.

3. The module end plate according to claim 1, characterized in that, The end plate, back plate, and reinforcing plate are all integrally stamped structures; a U-shaped notch is provided between the four enclosing surfaces of the end plate and back plate.

4. The module end plate according to claim 1, characterized in that, The reinforcing plate includes at least one U-shaped bending structure, with an extension plate perpendicular to the U-shaped bend on one side of the U-shaped bending structure, and the other side of the stress-bearing surface overlapping one side of the end plate back plate.

5. The module end plate according to claim 4, characterized in that, The reinforcing plate includes two U-shaped bending structures, with a connecting surface perpendicular to the U-bend between the two U-shaped bending structures. The connecting surface is provided with positioning holes corresponding to the positioning protrusions. One of the U-shaped bending structures overlaps the back plate of the end plate on the outside, and the other U-shaped bending structure is perpendicular to the extension plate of the U-bend on the inside.

6. The module end plate according to any one of claims 1-5, characterized in that, The reinforcing plate is provided with several limiting protrusions.

7. The module end plate according to claim 5, characterized in that, The end plate back plate is provided with two reinforcing plates, which are symmetrically arranged and positioned and welded to the positioning holes through positioning protrusions; the edge of the end plate back plate overlaps with the stress-bearing surface of the reinforcing plate.

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