Low-temperature-resistant lithium battery combination rack

Abstract

The utility model is used for lithium battery assembly technical field discloses a low temperature -resistant lithium battery combination frame, including bottom plate, set up in a plurality of containing cavities for fixing battery module of bottom plate and the side frame surrounded in the four around containing cavities, it is connected through displacement structure between the side frame and bottom plate, it includes: setting in the slide rail of bottom plate edge, and the gap is left between the cooperation surface of slide rail and side frame. This low temperature -resistant lithium battery combination frame, through setting by the displacement structure of slide rail and gap cooperation, make between side frame and bottom plate, and the adjacent side frame can occur relative displacement when temperature changes, this design cleverly converts the thermal stress originally concentrated on the rigid connection point into the mechanical displacement that can slide, thereby avoid the problem such as welding point cracking, structural deformation caused by stress concentration, significantly improve the structural stability and service life of combination frame under the cold and hot alternating environment.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery assembly technology, specifically a low-temperature resistant lithium battery assembly frame. Background Technology

[0002] With the rapid development of new energy vehicles, energy storage systems and portable electronic devices, lithium batteries have been widely used due to their advantages such as high energy density and long cycle life. However, the chemical characteristics of lithium batteries make their performance significantly affected by temperature. Especially in low-temperature environments, the conductivity of the electrolyte decreases and the impedance of the electrode interface increases, resulting in a sharp reduction in battery discharge capacity and charging efficiency. It may even cause safety problems such as lithium plating, which seriously restricts its reliable operation in cold regions.

[0003] Currently, to ensure the normal operation of lithium batteries in low-temperature environments, there are two main solutions: one is to start with the battery materials and internal structure, and develop low-temperature resistant electrolytes or special negative electrode materials, but such methods are costly and complex; the other is to adopt external thermal management solutions, such as integrating heating films and heating plates into the battery pack to preheat the battery modules. The second method has become the mainstream technical path because it is relatively simple to implement and cost-controllable.

[0004] However, in practical applications, especially for battery systems composed of multiple battery modules, the implementation of external heating solutions faces structural design challenges. Existing lithium battery racks or battery boxes mostly adopt rigid connection structures, fixing the supporting base plate, housing cavity, and outer side frame into a whole. When heating the battery in a low-temperature environment, there is a temperature difference between the rack itself (especially the metal parts) and the internal battery modules. The different thermal expansion coefficients of the materials in each part will generate complex thermal stress inside the structure. The long-term action of this alternating thermal stress can easily lead to fatigue cracking at the welding points and connections of the rack, deformation of the housing cavity due to compression, and even affect the fixing reliability of the battery modules, posing a safety hazard. In addition, conventional rigid structures have poor strain tolerance to thermal expansion and contraction, which may also directly transfer stress to the battery modules, causing compression of the cells and affecting their performance and lifespan.

[0005] Therefore, how to achieve effective low-temperature heating and heat preservation while solving the structural thermal stress problem caused by temperature changes, and designing a lithium battery assembly frame that can buffer, absorb or release thermal stress to ensure reliable fixing of the battery module and durability of the structure itself, has become an urgent technical problem to be solved in this field. Utility Model Content

[0006] The purpose of this invention is to provide a low-temperature resistant lithium battery assembly frame to solve the problem mentioned in the background art that the existing rigid lithium battery assembly frame has reduced structural reliability due to the difficulty in releasing thermal stress when the temperature changes.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a low-temperature resistant lithium battery assembly frame, comprising a base plate, a plurality of receiving cavities for fixing battery modules disposed on the base plate, and side frames surrounding the receiving cavities, wherein the side frames are connected to the base plate by a displacement structure.

[0008] The displacement structure includes: a slide rail disposed on the edge of the base plate, wherein a gap is left between the slide rail and the mating surface of the side frame, and a gap is left between adjacent end faces of the side frame;

[0009] The sidewall of the receiving cavity has a multi-layer nested structure, including an inner support, an outer support, and a buffer cavity located on the side where the inner and outer supports face each other. The inner and outer supports are connected by elastic ribs extending in the horizontal direction. There is a gap between the two adjacent inner supports and the two adjacent outer supports.

[0010] The four corners of the base plate are fixedly equipped with baffles, and the inner surface of the baffles facing the side frame is fixedly equipped with limit blocks, and one end of the limit block is in contact with the outer surface of the side frame.

[0011] Preferably, the elastic ribs are in the form of continuous "S"-shaped corrugations, and the two ends of the elastic ribs are located inside the buffer cavities on opposite sides of the inner and outer support layers, respectively.

[0012] By adopting the above technical solution, the "S"-shaped corrugated structure of the elastic rib and its end arrangement in the buffer cavity significantly enhance its elastic deformation capability, thereby more effectively absorbing and buffering the stress caused by the expansion or temperature change of the battery module, protecting the cell and extending the battery life.

[0013] Preferably, the inner wall of the side frame is provided with an annular heat insulation groove extending circumferentially, and the longitudinal section of the heat insulation groove is "T" shaped.

[0014] By adopting the above technical solution, the "T"-shaped cross-section annular insulation groove not only facilitates the installation and filling of high-performance insulation materials to form an effective thermal barrier layer, but its unique cross-sectional shape also enhances the adhesion and sealing of the insulation material, effectively reducing heat loss and improving the insulation effect in low-temperature environments.

[0015] Preferably, the upper surface of the base plate is provided with a heating film groove for installing the heating film, and stress relief holes are provided on the upper surface of the base plate outside the heating film groove.

[0016] The above technical solution allows for a more regular and tighter installation of the heating film groove, which helps to improve heating efficiency and temperature uniformity. The stress relief holes on its periphery can effectively release the micro-stress caused by uneven local heating of the base plate, prevent the base plate from warping and deforming, and ensure the flatness and structural stability of the overall base of the combined frame.

[0017] Compared with the prior art, the beneficial effects of this utility model are: the low-temperature resistant lithium battery assembly frame:

[0018] 1. By setting up a displacement structure consisting of slide rails and clearance fit, relative displacement can occur between the side frame and the bottom plate, as well as between adjacent side frames, when the temperature changes. This design cleverly transforms the thermal stress that was originally concentrated on the rigid connection point into a sliding mechanical displacement, thereby avoiding problems such as weld cracking and structural deformation caused by stress concentration, and significantly improving the structural stability and service life of the combined frame in alternating hot and cold environments.

[0019] 2. The housing cavity adopts an inner and outer support structure combined with a buffer cavity and elastic ribs to form an elastic constraint system. When the battery module expands slightly due to low-temperature charging or heat generation during operation, the inner support structure can transfer and buffer the pressure to the outer support structure through the deformation of the elastic ribs. At the same time, the buffer cavity provides deformation space. This design not only ensures the fixation of the battery module in the cavity, but also avoids excessive compression of the battery by the rigid cavity, protecting the battery cell and extending the battery life.

[0020] 3. By setting baffles and limiting blocks at the four corners of the base plate, the sliding side frame is provided with the final displacement limit. This ensures that the side frame can slide freely within the normal range of thermal expansion and contraction to release stress, while preventing it from falling out in extreme cases, thus ensuring the integration and safety boundary of the overall structure.

[0021] 4. The annular insulation groove on the inner side of the side frame facilitates the installation of high-performance insulation materials, forming an effective thermal barrier and reducing the loss of internal heat to the outside. The "T"-shaped cross section enhances the adhesion and sealing of the insulation material, while the heating film groove on the bottom plate makes the heating film installation more regular and tight, improving heating efficiency. The combination of these two factors optimizes the low-temperature start-up and insulation performance of the battery system and reduces energy consumption.

[0022] 5. Stress relief holes are opened on the base plate around the heating film tank, which can effectively release the micro-stress generated by local heating of the base plate, reduce the risk of warping and deformation of the base plate due to temperature difference, thereby ensuring the flatness of the entire assembly frame and the battery module mounting base and maintaining structural stability. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0024] Figure 2 This is a three-dimensional structural diagram of the connection between the base plate, side frame, and baffle of this utility model;

[0025] Figure 3 This is a schematic diagram of the overall cross-sectional three-dimensional structure of this utility model;

[0026] Figure 4 This is a three-dimensional structural diagram showing the connection between the base plate, baffle, and limiting block of this utility model;

[0027] Figure 5 This is a three-dimensional structural diagram showing the connection between the receiving cavity, inner support, and outer support of this utility model.

[0028] Figure 6 This is a three-dimensional structural diagram of the connection between the inner support, outer support, and elastic ribs of this utility model.

[0029] In the diagram: 1. Base plate; 2. Receiving cavity; 3. Side frame; 4. Slide rail; 5. Baffle; 6. Limiting block; 7. Insulation groove; 8. Stress relief hole; 9. Inner support; 10. Outer support; 11. Buffer cavity; 12. Elastic rib; 13. Heating film groove. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] Please see Figures 1-6 This utility model provides a technical solution: a low-temperature resistant lithium battery assembly frame.

[0032] Example 1: This example discloses: a base plate 1, multiple receiving cavities 2 for fixing battery modules disposed on the base plate 1, and side frames 3 surrounding the receiving cavities 2. The side frames 3 are connected to the base plate 1 through a displacement structure.

[0033] The displacement structure includes: a slide rail 4 set on the edge of the base plate 1, with a gap between the slide rail 4 and the mating surface of the side frame 3, and a gap between the end faces of adjacent side frames 3;

[0034] A baffle 5 is fixedly installed on the upper surface of the four corners of the base plate 1, and a limiting block 6 is fixedly installed on the inner surface of the baffle 5 facing the side frame 3, and one end of the limiting block 6 is in contact with the outer surface of the side frame 3.

[0035] The inner wall of the side frame 3 is provided with an annular heat insulation groove 7 extending in the circumferential direction, and the longitudinal section of the heat insulation groove 7 is "T" shaped.

[0036] The upper surface of the base plate 1 is provided with a heating film groove 13 for installing a heating film, and stress relief holes 8 are provided on the upper surface of the base plate 1 outside the heating film groove 13.

[0037] Low-temperature heating and thermal stress generation: When the battery needs to start or work in a low-temperature environment, the heating film installed in the heating film groove 13 on the base plate 1 starts to work and preheats the battery module. At the same time, the annular heat preservation groove 7 on the inner side wall of the side frame 3 can be filled with heat preservation material to reduce heat loss. Since there is a temperature difference between the metal base plate 1, side frame 3 and the internal battery module and heating film, and the thermal expansion coefficients of their respective materials are different, thermal stress will be generated inside the structure.

[0038] Core stress relief mechanism – displacement structure: To solve the above-mentioned thermal stress, the core of this design is the displacement structure. The bottom plate 1 is equipped with a slide rail 4, and the side frame 3 is installed on it. The key point is that there are gaps between the mating surfaces of the slide rail 4 and the side frame 3, as well as between the end faces of adjacent side frames 3. When the temperature changes and causes thermal expansion and contraction of various parts, the side frame 3 can slide slightly relative to the bottom plate 1 along the slide rail 4, and adjacent side frames 3 can also move relative to each other. This design transforms the rigid stress that would originally be concentrated at the welding point or fixed connection into a freely movable mechanical displacement, thereby avoiding fatigue cracking or deformation caused by stress concentration.

[0039] Displacement limiting and micro-stress release: To ensure safe and controllable sliding, baffles 5 are fixedly installed at the four corners of the base plate 1. The limiting blocks 6 on the inner side of the baffles 5 are in contact with the outer surface of the side frame 3. The limiting blocks 6 allow the side frame 3 to slide within the normal range of thermal expansion and contraction, but when subjected to severe impact or abnormal displacement, they can limit it to a safe range to prevent it from falling out. In addition, stress relief holes 8 are opened on the base plate 1 outside the heating film groove 13. They can effectively release the micro-stress generated by uneven local heating of the base plate 1 itself, prevent the base plate 1 from warping, and ensure the flatness of the installation surface.

[0040] This embodiment uses a displacement structure consisting of a slide rail 4 and a gap to allow the side frame 3 and the base plate 1 to slide relative to each other, absorbing thermal stress through macroscopic displacement. The sliding boundary is controlled by the baffle 5 and the limiting block 6, and the microscopic stress of the base plate 1 is released through the stress relief hole 8. At the same time, the heating film groove 13 and the heat preservation groove 7 are used to improve the low-temperature performance, thus systematically solving the problem that rigid frames are easily damaged by thermal stress.

[0041] Example 2: This example discloses the following based on Example 1: The sidewall of the receiving cavity 2 is a multi-layer nested structure, including an inner support 9, an outer support 10, and a buffer cavity 11 located on the side where the inner support 9 and the outer support 10 face each other. The inner support 9 and the outer support 10 are connected by elastic ribs 12 extending in the horizontal direction. There is a gap at the opposite end of two adjacent inner supports 9 and a gap at the opposite end of two adjacent outer supports 10.

[0042] The elastic rib 12 is in the form of a continuous "S" shaped corrugation, and the two ends of the elastic rib 12 are located inside the buffer cavity 11 on the opposite side of the inner support 9 and the outer support 10, respectively.

[0043] The core improvement of this embodiment lies in the side wall structure of the receiving cavity 2. The side wall is composed of an inner support 9 and an outer support 10, with a buffer cavity 11 between them and connected by a horizontal elastic rib 12. The elastic rib 12 is in the form of a continuous S-shaped corrugation, with its two ends located in the buffer cavity 11 of the inner support 9 and the outer support 10, respectively, which gives it good elastic deformation capability.

[0044] Battery expansion stress absorption process: During low-temperature charging or operation, the battery module itself may expand slightly, exerting an outward force on the cavity wall that houses it. At this time, the inner support 9 that is in direct contact with the battery is compressed. Since there is a gap between adjacent inner supports 9, the inner support 9 can transfer the pressure to the outer support 10 through the elastic ribs 12. The S-shaped elastic ribs 12 undergo elastic deformation. At the same time, the buffer cavity 11 between the inner support 9 and the outer support 10 provides valuable deformation space. This process is like a "spring damping system", which converts the rigid compressive force of battery expansion into the elastic potential energy of the elastic ribs 12 and the space of the buffer cavity 11, thus effectively buffering and absorbing it.

[0045] Collaborative working mechanism: The stress of battery expansion is first buffered by the elastic structure of the housing cavity 2. If the stress is large or accompanied by thermal deformation of the overall frame, the remaining force will be transmitted to the entire assembly frame. At this time, the displacement structure of Embodiment 1 will be activated to perform secondary release. The baffle 5 and the limiting block 6 ensure that the entire system works within the safe displacement range.

[0046] This embodiment, while possessing all the macroscopic thermal stress relief functions of the first embodiment, adds a microscopic elastic buffer system for battery module expansion. Through the synergistic effect of the inner support 9, outer support 10, buffer cavity 11 and elastic rib 12, a flexible battery constraint unit is formed. Under the premise of ensuring reliable fixation, the rigid cavity is avoided from squeezing the battery, thus achieving dual protection for the battery and the assembly frame structure.

[0047] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-temperature resistant lithium battery assembly rack, comprising a base plate (1), a plurality of receiving cavities (2) disposed on the base plate (1) for fixing battery modules, and side frames (3) surrounding the receiving cavities (2), characterized in that: The side frame (3) and the base plate (1) are connected by a displacement structure; The displacement structure includes: a slide rail (4) disposed on the edge of the base plate (1), with a gap between the slide rail (4) and the mating surface of the side frame (3), and a gap between the end faces of adjacent side frames (3).

2. The low-temperature resistant lithium battery assembly frame according to claim 1, characterized in that: The sidewall of the receiving cavity (2) is a multi-layer nested structure, including an inner support (9), an outer support (10), and a buffer cavity (11) located on the side where the inner support (9) and the outer support (10) face each other. The inner support (9) and the outer support (10) are connected by elastic ribs (12) extending in the horizontal direction. There is a gap between the two adjacent inner supports (9) facing each other and a gap between the two adjacent outer supports (10) facing each other.

3. The low-temperature resistant lithium battery assembly frame according to claim 2, characterized in that: The elastic rib (12) is in the shape of a continuous "S" shaped corrugation, and the two ends of the elastic rib (12) are located inside the buffer cavity (11) on the opposite side of the inner support (9) and the outer support (10).

4. The low-temperature resistant lithium battery assembly frame according to claim 1, characterized in that: The base plate (1) has baffles (5) fixedly installed on the upper surface of the four corners, and the baffles (5) are fixedly installed with limiting blocks (6) facing the inner surface of the side frame (3), and one end of the limiting block (6) is attached to the outer surface of the side frame (3).

5. A low-temperature resistant lithium battery assembly frame according to claim 1, characterized in that: The inner wall of the side frame (3) is provided with an annular heat preservation groove (7) extending in the circumferential direction, and the longitudinal section of the heat preservation groove (7) is "T" shaped.

6. A low-temperature resistant lithium battery assembly frame according to claim 1, characterized in that: The upper surface of the base plate (1) is provided with a heating film groove (13) for installing the heating film, and stress relief holes (8) are opened on the upper surface of the base plate (1) outside the heating film groove (13).

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