A battery device

Abstract

The utility model provides a kind of battery device, and it relates to battery technical field.A kind of battery device, comprising: bottom plate;Battery cell group, is set on bottom plate;Clamp plate, is set on the side of battery cell group away from bottom plate;First foam, is set between battery cell group and clamp plate, first foam respectively with battery cell group and clamp plate are in contact;Wherein, the thickness of first foam continuously decreases or step decreases from center position to both ends along the length direction of battery cell group.The utility model replaces 1-1.5mm thick thin clamp plate for traditional 10mm or more aluminum profile or 5-8mm steel plate, and cooperates with special structure foam, so that the thickness and weight of clamp plate are reduced by more than 60%, more space is provided for battery, more power is arranged, so as to improve energy density and improve endurance.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, and specifically relates to a battery device. Background Technology

[0002] With the rapid development of the new energy vehicle market, users' expectations for vehicle range continue to rise. As the core energy source of the entire vehicle, the energy density of the power battery has become one of the key indicators for industry research and development. To improve the overall energy density of the battery pack, it is necessary to optimize the chemical system and structural design of the cells themselves, and to achieve lightweighting and efficient space utilization at the battery pack system level.

[0003] In practical applications of power batteries, especially battery systems using pouch cells, the cells undergo volume expansion during charge-discharge cycles, a phenomenon particularly pronounced at the end of battery life (EOL). Without applying appropriate restraint to the cells, this expansion leads to uneven internal structural stress, triggering side reactions such as lithium plating and interface delamination, severely shortening battery cycle life. Therefore, existing technologies typically incorporate rigid clamps in the cell stacking direction and place foam material between the clamps and the cells to provide uniform and stable pre-tightening restraint.

[0004] Currently, mainstream solutions generally employ thick, rigid clamping plates, such as aluminum profiles thicker than 10mm or steel plates 5-8mm thick, to ensure that the clamping plates do not deform significantly under the expansion force of the battery cells (0.3–0.5MPa). While these clamping plates effectively maintain structural rigidity and ensure uniform compression of the foam, thereby transmitting consistent constraint force to the surface of the battery cells, their large weight and space requirements severely restrict the improvement of battery pack energy density and the goal of lightweighting.

[0005] Therefore, there is an urgent need for a new type of battery device structure that can ensure uniform and stable constraint on the cells throughout their entire life cycle while using thin and light clamps, thereby achieving the design goals of high energy density, long cycle life and lightweight system. Utility Model Content

[0006] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a battery device.

[0007] The objective of this utility model can be achieved through the following technical solution: A battery device, comprising:

[0008] Base plate;

[0009] The battery cell assembly is mounted on the base plate;

[0010] A clamping plate is located on the side of the battery cell assembly away from the base plate;

[0011] A first foam is disposed between the battery cell assembly and the clamping plate, and the first foam abuts against the battery cell assembly and the clamping plate respectively;

[0012] The thickness of the first foam decreases continuously or in steps from the center to both ends along the length of the battery cell assembly.

[0013] As a further improvement of this utility model, the first foam is configured as multiple layers, and the width of each layer gradually decreases from bottom to top.

[0014] As a further improvement of this utility model, the first foam is configured with 3-5 layers, and the thickness of the clamping plate is configured with 1-1.5 mm.

[0015] As a further improvement of this utility model, the first foam is configured as a single piece, and the side of the first foam near the clamp is configured as stepped or arc-shaped.

[0016] As a further improvement of this utility model, it also includes a pressure sensor, which is disposed between the first foam and the battery cell assembly.

[0017] As a further improvement of this utility model, it also includes a second foam, which is disposed between the battery cell assembly and the base plate.

[0018] As a further improvement of this utility model, the battery cell group is configured as a plurality of cells, and a second foam is provided between two adjacent battery cell groups.

[0019] As a further improvement of this utility model, the second foam is configured as a flat sheet.

[0020] As a further improvement of this utility model, the battery cell assembly includes at least one battery cell, and when the battery cell assembly includes multiple battery cells, the multiple battery cells are sequentially connected to each other.

[0021] As a further improvement of this utility model, it also includes an end plate, which is disposed between the base plate and the clamping plate. The end plate is fixedly connected to the clamping plate and the base plate respectively, and the end plate is configured as two, which are respectively disposed on both sides of the battery cell assembly.

[0022] Based on the above technical solution, this utility model can produce at least the following technical effects:

[0023] 1. This utility model replaces the traditional aluminum profiles of 10mm or more or steel plates of 5-8mm with thin plates of 1-1.5mm thickness, and with special structured foam, the thickness and weight of the plates are reduced by more than 60%, providing more space for the battery and accommodating more power, thereby improving energy density and reducing weight, and improving battery life.

[0024] 2. The new foam structure adopted (multi-layer stepped stacked, integrally molded stepped or arc-shaped structure) can still ensure that the foam in the middle area is effectively compressed by the local thickening design when the middle of the sandwich plate is deformed due to insufficient rigidity. This maintains the required preload force on the entire surface of the cell (especially in the middle of the wide cell). Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the battery device of this utility model.

[0027] Figure 2 This is a schematic diagram of the first structure of the first foam in this utility model.

[0028] Figure 3 This is a schematic diagram of the second structure of the first foam in this utility model.

[0029] Figure 4 This is a schematic diagram of the third structure of the first foam in this utility model.

[0030] In the diagram, 100 is the base plate; 200 is the battery cell assembly; 210 is the battery cell; 300 is the clamping plate; 400 is the first foam; 500 is the second foam; 600 is the end plate; and 700 is the pressure sensor. Detailed Implementation

[0031] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this utility model are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indication will also change accordingly. Furthermore, in this utility model, descriptions involving "first," "second," "a," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly defined. In this utility model, unless otherwise explicitly specified and defined, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to the specific circumstances. Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope claimed by this utility model.

[0032] The following are specific embodiments of this utility model, in conjunction with the accompanying drawings. Figure 1-4 The technical solution of this utility model will be further described below, but this utility model is not limited to the following embodiments.

[0033] This utility model provides a lightweight battery device, mainly applicable to power battery systems for new energy vehicles, especially suitable for large-size battery modules using pouch cells 210. The overall structure of the device includes a base plate 100, a cell assembly 200 disposed on the base plate 100, a clamping plate 300 located on the side of the cell assembly 200 away from the base plate 100, and a first foam 400 disposed between the cell assembly 200 and the clamping plate 300. Furthermore, auxiliary structures such as a second foam 500 can be configured as needed to further improve overall performance and assembly stability.

[0034] In this embodiment, the base plate 100 can be made of aluminum alloy or high-strength engineering plastic, and its main function is to support the entire cell assembly 200 and serve as the mounting reference surface for the battery module. The cell assembly 200 is composed of one or more pouch cells 210 laid flat in sequence. Adjacent cells 210 can directly abut against each other, or thermal pads can be provided according to thermal management requirements. When there are a large number of cells 210, the expansion force generated by the cells 210 during charge and discharge cycles is particularly significant in the central region, which places higher demands on the constraint structure.

[0035] The clamping plate 300 is positioned above the cell assembly 200 (i.e., on the side away from the base plate 100) to apply a vertical pre-tightening constraint force to the cell 210. Unlike the prior art, which commonly uses aluminum profiles thicker than 10mm or steel plates thicker than 5–8mm, the clamping plate 300 in this invention uses a steel plate or high-strength aluminum alloy sheet with a thickness of only 1.0–1.5mm. This thickness selection is the result of optimization based on a comprehensive consideration of material stiffness, cost, weight, and processing technology. Although the thin clamping plate 300 will inevitably undergo a certain degree of central arching deformation under the expansion force of the cell 210 of 0.3–0.5MPa, this invention effectively compensates for the negative impact of this deformation through the innovative design of the first foam 400 structure.

[0036] The key difference lies in the fact that the first foam 400 in this invention is not a traditional flat structure with uniform thickness, but rather its thickness decreases continuously or in a stepped manner from the center to both ends along the length of the cell assembly 200. Specifically, the first foam 400 can be implemented in two main ways: one is a multi-layer stacked structure, and the other is a one-piece molded structure. In the multi-layer stacked structure, the first foam 400 is formed by stacking 3 to 5 layers of foam sheets from bottom to top, with the width of each layer decreasing progressively, thus creating an overall profile that is thicker in the middle and thinner at the edges. For example, the width of the bottom layer of foam can be equivalent to the width of the cell assembly 200, the second layer is slightly narrower, the third layer is even narrower, and so on. This design ensures that even if the middle of the clamping plate 300 arches upward due to insufficient rigidity, the contact area with the foam is still in a thicker foam area, thus ensuring that the foam in this area is fully compressed and generates sufficient reaction force to be transmitted to the surface of the cell 210.

[0037] In a one-piece molded structure, the first foam 400 can be directly fabricated into a monolithic part with a specific geometry through a mold foaming process. Its side near the clamping plate 300 can be designed as a stepped or curved surface. The stepped structure achieves a gradual transition in thickness through several horizontal steps, while the curved structure achieves a smooth thickness change through a continuous curved surface. Regardless of the form used, the core idea is to ensure that the foam has a larger initial thickness in the area where the clamping plate 300 is expected to deform the most, thereby maintaining effective compression after the clamping plate 300 deforms and ensuring a uniform distribution of constraint force.

[0038] In a further optimized embodiment of this utility model, the battery device may further include at least one pressure sensor 700, which is disposed between the first foam 400 and the cell assembly 200. The pressure sensor 700 is used to monitor in real time the actual constraint pressure experienced by the cell 210 during charge-discharge cycles and transmits the collected pressure signal to the battery management system. The battery management system can dynamically evaluate the effectiveness of the clamping plate 300 constraint based on the pressure data, determine whether there are abnormalities such as foam aging, clamping plate 300 loosening, or local failure, and trigger an early warning when necessary.

[0039] Experiments showed that in the control group using conventional uniform thickness foam combined with a 1.2mm thin steel plate 300, a large area in the center of the battery cell 210 surface experienced almost no constraint force, with the stress in this area approaching zero, as indicated by the contour plot. However, in the experimental group using the novel foam structure described in this invention combined with a 10mm thick aluminum profile 300 and conventional foam, the uniformity of constraint force distribution at various locations on the battery cell 210 surface was significantly improved, and its stress state was comparable to the traditional solution using a 10mm thick aluminum profile 300 and conventional foam. This fully demonstrates that this invention successfully achieves effective constraint on the expansion of the battery cell 210 while significantly reducing weight and thickness.

[0040] To further improve the overall stability of the battery module, this invention may also include a second foam 500. The second foam 500 can be positioned between the cell assembly 200 and the base plate 100 to buffer bottom vibration, improve heat conduction, or provide additional preload. When multiple cell assemblies 200 are configured, the second foam 500 can also be positioned between multiple cell assemblies 200 to absorb expansion stress or enhance thermal insulation performance. It is worth noting that the second foam 500 typically adopts a flat plate structure, as its location is not affected by the deformation of the clamping plate 300, eliminating the need for a variable thickness design, thereby simplifying the manufacturing process and reducing costs.

[0041] Furthermore, the battery device of this utility model also includes two end plates 600, respectively disposed on both sides of the cell assembly 200 along its length. The end plates 600 connect the base plate 100 and the clamping plate 300, and are typically fixed by bolts, riveting, or welding to form a closed or semi-closed frame structure. This frame not only enhances the overall mechanical strength of the module, but also effectively restricts the displacement of the cell 210 in the length direction. Working in conjunction with the vertical constraint system, it constructs a three-dimensional constraint system, comprehensively improving the structural reliability and cycle durability of the battery module.

[0042] In the actual assembly process, the base plate 100 is first placed horizontally, followed by the second foam 500 and the cell assembly 200, then the first foam 400 is laid on top of the cell assembly 200, and finally the thin clamping plate 300 is covered and locked to the base plate 100 by the end plate 600. During assembly, the bolt preload can be controlled by torque to ensure that the foam is moderately compressed in the initial state, thereby maintaining effective constraint throughout the battery's entire life cycle. Since the non-uniform thickness design of the first foam 400 has pre-compensated for the deformation tendency of the clamping plate 300, there is no need to excessively increase the thickness of the clamping plate 300 or use expensive high-rigidity materials, significantly reducing system weight and cost.

[0043] In summary, this utility model achieves lightweighting of the battery device by organically combining the thin and light clamping plate 300 with the non-uniform thickness foam structure without sacrificing the constraint performance of the battery cell 210.

[0044] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A battery device, characterized in that, include: Base plate (100); A battery cell assembly (200) is disposed on the base plate (100); A clamping plate (300) is disposed on the side of the cell assembly (200) away from the base plate (100); A first foam (400) is disposed between the battery cell assembly (200) and the clamping plate (300), and the first foam (400) abuts against the battery cell assembly (200) and the clamping plate (300) respectively; The thickness of the first foam (400) decreases continuously or in steps from the center to both ends along the length of the battery cell assembly (200).

2. The battery device according to claim 1, characterized in that, The first foam (400) is configured as multiple layers, with the width of each layer gradually decreasing from bottom to top.

3. The battery device according to claim 2, characterized in that, The first foam (400) is configured with 3-5 layers, and the thickness of the clamping plate (300) is configured with 1-1.5 mm.

4. The battery device according to claim 1, characterized in that, The first foam (400) is integrally formed. The side of the first foam (400) near the clamp (300) is set in a stepped or arc shape.

5. The battery device according to claim 1, characterized in that, It also includes a pressure sensor (700) disposed between the first foam (400) and the battery cell assembly (200).

6. The battery device according to claim 1, characterized in that, It also includes a second foam (500) disposed between the battery cell assembly (200) and the base plate (100).

7. The battery device according to claim 6, characterized in that, The battery cell group (200) is configured as a plurality of cells, and a second foam (500) is provided between two adjacent battery cell groups (200).

8. The battery device according to claim 6, characterized in that, The second foam (500) is configured as a flat sheet.

9. The battery device according to claim 1, characterized in that, The battery cell assembly (200) includes at least one battery cell (210), and when the battery cell assembly (200) includes multiple battery cells (210), the multiple battery cells (210) are sequentially abutted.

10. The battery device according to claim 1, characterized in that, It also includes an end plate (600), which is disposed between the base plate (100) and the clamping plate (300). The end plate (600) is fixedly connected to the clamping plate (300) and the base plate (100) respectively. There are two end plates (600), which are respectively disposed on both sides of the battery cell assembly (200).

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