Sealing structure with self-repairing function, battery pack assembly and vehicle

Abstract

The invention relates to the technical field of sealing, in particular to a sealing structure with a self-repairing function, a battery pack assembly and a vehicle, the sealing structure comprises a sealing layer arranged between a first component and a second component, a plurality of containing grooves are formed in the side, close to the sealing layer, of the first component, and self-repairing adhesives are contained in the containing grooves; in response to cracks generated on the sealing layer, the self-repairing adhesive is released into the cracks, and the cracks are cured and repaired. Active repair of cracks of the sealing layer can be realized, and the safety and the service life of a battery system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealing, in particular to a sealing structure with self-repairing function, a battery pack assembly and a vehicle. BACKGROUND

[0002] In the safe operation system of the battery system, the sealing performance between the battery frame and the water-cooled plate is the core factor to determine the safety and service life of the battery. The current mainstream sealing scheme mainly relies on sealing gaskets or sealing glue to fill the joints, but such structures are prone to micro-cracks due to stress concentration when in long-term service or subjected to external impact. Once such defects occur, not only may the coolant leak or the electrolyte seep out, but also may directly induce battery thermal runaway and other serious consequences that endanger the safety of the system.

[0003] The related art discloses a technical scheme for strengthening the sealing effect by setting grooves on the periphery of the box body and the cover body, and cooperating with the sealing assembly. However, this scheme only realizes static sealing by physical compression, does not involve the active repair mechanism of the sealing layer cracks, and is difficult to cope with the sealing failure problem caused by dynamic stress changes. In addition, the related art also proposes a technical idea for improving corrosion resistance based on the self-repairing characteristics of zinc-aluminum-magnesium alloy plating. However, this technology is only applicable to surface damage repair in a static environment, and cannot realize the active release of the repair material to fill internal cracks.

[0004] In summary, the existing technology has two major defects: first, the sealing structure generally lacks self-repairing ability and is difficult to actively inhibit crack propagation; second, the application of self-repairing materials is limited to optimization of the material's own properties, and has not yet formed an active repair system in cooperation with the sealing structure. Therefore, it has become an urgent need for the industry to develop a new sealing structure that can actively repair sealing layer cracks and significantly improve the reliability of the battery system. SUMMARY

[0005] The purpose of the present application is to provide a sealing structure with self-repairing function, a battery pack assembly and a vehicle, which can realize active repair of sealing layer cracks and improve the safety and service life of the battery system.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: In a first aspect, the present application discloses a sealing structure with self-repairing function, comprising a sealing layer arranged between a component one and a component two, the component one being provided with a plurality of accommodation grooves on the side close to the sealing layer, and the accommodation grooves containing self-repairing adhesive, the self-repairing adhesive being released into the cracks in response to cracks generated on the sealing layer, and solidifying to repair the cracks.

[0007] Further, the self-repairing adhesive comprises a resin matrix and dicyclopentadiene microcapsules and ruthenium carbene catalyst uniformly dispersed in the resin matrix.

[0008] Further, the self-repairing adhesive comprises a solid or semi-solid polyurethane or acrylate.

[0009] Further, the groove wall of the accommodation groove is coated with a nanoscale silica coating.

[0010] Further, the depth of the accommodation groove is 1-1.5 mm, and the width is 1.5-2.5 mm.

[0011] Further, the spacing between adjacent accommodation grooves is 2-2.5 mm, and adjacent accommodation grooves are connected by flow guide grooves.

[0012] Further, the thickness of the sealing layer is 3-5 mm.

[0013] In a second aspect, the present application discloses a battery pack assembly comprising the sealing structure with self-repairing function.

[0014] Further, the battery frame and the water-cooled plate are arranged with the sealing structure with self-repairing function, and the bottom surface of the battery frame is provided with a plurality of accommodation grooves for accommodating the self-repairing adhesive.

[0015] In a third aspect, the present application discloses a vehicle comprising the battery pack assembly.

[0016] The present application has the following unexpected beneficial effects: 1. The present application sets a plurality of accommodation grooves on one side of the component close to the sealing layer, and the accommodation grooves contain self-repairing adhesive. When the sealing layer cracks due to long-term use, external impact or other factors, the self-repairing adhesive in the accommodation grooves can be released and enter the cracks in time, and the cracks can be repaired by solidification. Thus, the problem that the traditional sealing structure cannot self-heal after cracking and can only rely on manual maintenance is solved, the leakage of coolant and the leakage of electrolyte are effectively prevented, and the safety hazards such as thermal runaway caused by sealing failure of the battery system are greatly reduced. Moreover, the self-repairing function can repair the cracks multiple times, delay the aging and damage speed of the sealing layer, reduce the maintenance and replacement frequency of the sealing structure, indirectly prolong the overall service life of the battery system, and reduce the long-term use cost.

[0017] 2. The sealing structure combines the self-repairing function with the sealing layer, without the need for additional complex repair devices, while ensuring the sealing effect and simplifying the overall structure of the sealing system. The design of the accommodation grooves can be flexibly arranged without affecting the installation of other components of the battery system, which is conducive to improving the space utilization and structural integration of the battery system. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in 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 some embodiments of the present invention.

[0019] Figure 1 A schematic diagram of one embodiment of the sealing structure with self-healing function described in this invention is shown.

[0020] Figure 2 A schematic diagram of another embodiment of the sealing structure with self-healing function described in this invention is shown.

[0021] Figure 3 A schematic diagram of another embodiment of the sealing structure with self-healing function described in this invention is shown.

[0022] Figure 4 A schematic diagram of another embodiment of the sealing structure with self-healing function described in this invention is shown. Detailed Implementation

[0023] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0024] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0025] In one embodiment, the present invention provides a sealing structure with self-healing function, see [link to previous embodiment]. Figure 1 As shown, a sealing layer 3 is arranged between component 1 and component 2. Component 1 has a plurality of receiving grooves 4 on the side near the sealing layer 3. The receiving grooves 4 contain self-healing adhesive 5. In response to the generation of cracks on the sealing layer 3, the self-healing adhesive 5 is released into the cracks and cures to repair the cracks.

[0026] The application solves the problem that the traditional sealing structure cannot self-heal after cracks appear and can only rely on manual maintenance, effectively prevents leakage of coolant, electrolyte and other situations, and greatly reduces the safety hazards such as thermal runaway caused by sealing failure of the battery system.

[0027] Once the traditional sealing structure has cracks, if not handled in time, the cracks will continue to expand, eventually leading to the failure of the entire sealing structure, and the sealing assembly needs to be replaced frequently. The sealing structure described in the application can repair cracks multiple times through the self-repairing function, delay the aging and damage speed of the sealing layer 3, reduce the maintenance and replacement frequency of the sealing structure, indirectly prolong the overall service life of the battery system, and reduce the long-term use cost.

[0028] During the operation of the battery system, dynamic stress may be generated due to temperature changes, vibrations and other factors, and the traditional sealing structure is easily affected by such stress and sealing failure occurs. The self-repairing mechanism in the sealing structure described in the application can actively respond to cracks caused by dynamic stress, maintain the stability of the sealing performance through timely repair, and make the sealing structure more suitable for complex working environments.

[0029] The sealing structure described in the application combines the self-repairing function with the sealing layer 3, without the need for additional complex repair devices, while ensuring the sealing effect, the overall structure of the sealing system is simplified. The design of the accommodation groove 4 can be flexibly arranged on one side of the component one 1, without affecting the installation of other components of the battery system, which is conducive to improving the space utilization and structural integration of the battery system.

[0030] As a preferred embodiment of the application, the self-repairing adhesive 5 includes a resin matrix and dicyclopentadiene microcapsules and ruthenium carbene catalyst uniformly dispersed in the resin matrix. Specifically, the self-repairing adhesive is selected from epoxy resin including dicyclopentadiene (DCPD) microcapsules, and the dicyclopentadiene microcapsules have a diameter of 50-100 μm and are uniformly dispersed in the epoxy resin matrix.

[0031] The preferred embodiment selects a combination system of dicyclopentadiene microcapsules and ruthenium carbene catalyst, which utilizes the ring-opening metathesis polymerization reaction that occurs when the two come into contact, to achieve rapid curing at the crack. This reaction has high efficiency and can be activated rapidly after the sealing layer is cracked by impact, avoiding the further expansion of the leakage risk caused by crack expansion before repair, compared with the traditional repair method relying on slow penetration or physical filling of materials, which greatly shortens the repair period.

[0032] The diameter of the dicyclopentadiene microcapsule is controlled at 50-100 pm, which not only ensures that the amount of DCPD stored in the capsule is sufficient to fill the crack of the corresponding size, but also can be uniformly dispersed in the epoxy resin matrix, ensuring that the probability of capsule rupture is higher when the crack occurs, the release of the repair material is more sufficient, and the success rate of single repair is improved.

[0033] The solid-state storage form of the dicyclopentadiene microcapsule can stably exist in the accommodation groove, and only when the crack in the sealing layer occurs, the mechanical force generated by the crack propagation causes the microcapsule to rupture, releasing DCPD for reaction with the catalyst. This on-demand release mechanism avoids the wasteful consumption of repair materials and only activates when real repair is needed, improving the pertinence of self-repair. Moreover, the microcapsule structure physically separates DCPD and the catalyst, preventing premature reaction between them in the unused state, ensuring the long-term storage stability of the self-repair adhesive 5, which is suitable for the long-term service requirement of the battery system.

[0034] The preferred embodiment uses an epoxy resin matrix as the carrier of the self-repair adhesive 5, which has good bonding and sealing properties and is highly compatible with the sealing layer material, ensuring the stable storage of the microcapsule in the accommodation groove, while forming a synergistic sealing effect with the polymerized DCPD during the repair process, enhancing the repair strength at the crack.

[0035] The self-repair adhesive is filled into the accommodation groove using a vacuum impregnation method, and after curing, a solid-state storage layer is formed. When the battery is hit and causes a crack in the sealing gasket, the dicyclopentadiene microcapsule is ruptured, the dicyclopentadiene contacts the ruthenium carbene catalyst in the epoxy resin and undergoes a ring-opening metathesis polymerization reaction, rapidly curing and filling the crack. The unbroken dicyclopentadiene microcapsule remains in the accommodation groove and can meet the subsequent multiple crack repair needs.

[0036] The preferred embodiment uses a vacuum impregnation method to fill the self-repair adhesive 5, which can ensure that there are no air bubbles remaining in the accommodation groove 4, the self-repair adhesive 5 is filled more fully, and the solid-state storage layer formed after curing has a uniform structure, avoiding premature rupture of the microcapsule or uneven distribution of the repair material due to local defects.

[0037] The unbroken dicyclopentadiene microcapsule can be retained in the accommodation groove 4 for a long time, and when the sealing layer 3 is subsequently cracked again due to vibration, temperature changes, etc., the repair mechanism can still be repeatedly triggered, meeting the multiple crack repair needs. This one-time filling, multiple use feature solves the limitation of traditional self-repair materials that are invalid after single repair, significantly extending the effective service period of the sealing structure and reducing maintenance costs.

[0038] As a preferred embodiment of the present application, the self-repair adhesive 5 includes a solid or semi-solid polyurethane or acrylate.

[0039] The self-repairing adhesive 5 is mainly composed of polyurethane or acrylate. When the sealing layer 3 is broken, a small amount of electrolyte or water vapor in the environment penetrates into the self-repairing adhesive 5, which swells or dissolves after being in contact with the electrolyte, changes into a flowing state to fill the cracks, and then solidifies again after the solvent evaporates. The repair trigger is directly related to the crack generation, and is highly targeted, especially suitable for repairing micro-cracks in the early stage of battery sealing failure.

[0040] The self-repairing adhesive 5 in the preferred embodiment uses the penetration of electrolyte or environmental water vapor as the repair trigger, which is directly related to the core risk of battery sealing failure (electrolyte leakage). When the sealing layer 3 has micro-cracks, the micro-leakage of electrolyte will immediately start the repair process, realizing the precise linkage of crack generation and repair response, and avoiding the problems of false triggering or delayed triggering in the traditional repair mechanism. It is especially suitable for repairing micro-cracks in the early stage of sealing failure. In the stage where the crack has not expanded and only a small amount of electrolyte has penetrated, the swelling / dissolving-flowing-solidifying process of the self-repairing adhesive 5 can timely block the cracks, curb the crack expansion and leakage aggravation from the source, and greatly reduce the safety hazards.

[0041] Polyurethane or acrylate is selected as the main material, both of which have good chemical stability and are compatible with the battery electrolyte, and are not prone to chemical reactions that cause material failure. At the same time, the adhesive layer formed after curing has certain elasticity and temperature resistance, which can adapt to temperature fluctuations and vibration environment during battery operation, ensuring the long-term stability of the sealing performance after repair. The material itself is in a dry solid state or high-viscosity semi-solid state, and is in a stable state when not in contact with the electrolyte, which will not cause loss during storage or additional impact on the sealing layer due to its own flowability, and is suitable for long-term storage of battery systems in static or running state.

[0042] The repair process relies on the physical and chemical action (swelling, dissolution, solvent evaporation and solidification) of the material and the electrolyte, which does not require external energy or complex reaction conditions and is fully compatible with the closed environment of the battery system. The flow filling and re-solidification can be completed independently in the sealing layer, which has high repair efficiency and does not interfere with the normal operation of the battery. The flowing adhesive can fully infiltrate the fine structure of the crack, especially for irregular micro-cracks, and has better filling effect than rigid repair materials, which can realize the overall sealing of the crack and improve the sealing integrity after repair.

[0043] As a preferred embodiment of the present application, the groove wall of the accommodation groove 4 is coated with a nano-sized silicon dioxide coating.

[0044] The nanoscale silicon dioxide coating has extremely low surface energy, which can significantly reduce the adhesion between the self-healing adhesive 5 and the groove wall of the accommodation groove 4. When the sealing layer 3 cracks and triggers the repair mechanism (such as the rupture of microcapsules, the infiltration of electrolyte to trigger the state change of the adhesive, etc.), the self-healing adhesive 5 can flow more smoothly and quickly to the crack, reducing the release delay caused by excessive adhesion. For the battery system, the repair window period after sealing failure is crucial, and the drag-reducing effect of the coating can shorten the time of the self-healing adhesive 5 from the storage state to the crack filling, avoid further expansion of the crack before repair, and improve the emergency protection capability of the overall sealing structure.

[0045] Whether it is an epoxy resin adhesive containing dicyclopentadiene microcapsules or a polyurethane or acrylate adhesive, the low adhesion of the nanoscale silicon dioxide coating can effectively adapt. For solid or semi-solid self-healing adhesives, it can reduce the resistance of the adhesive to the groove wall; for adhesives that change to a flowing state due to reaction or swelling, it can reduce the resistance during flow, so that different types of self-healing materials can be released efficiently, enhancing the compatibility of the sealing structure for diverse repair systems.

[0046] As a preferred embodiment of the present application, referring to Figure 1 As shown in the figure, the depth a of the accommodation groove 4 is 1-1.5 mm, and the width b is 1.5-2.5 mm.

[0047] The size range defined in this preferred embodiment can accommodate an appropriate amount of self-healing adhesive 5, which not only ensures the amount of material needed for a single repair, sufficient to fill common microcracks and moderate cracks in the battery sealing layer, but also avoids material waste or excessive occupation of internal space in the battery system due to oversized grooves. Moreover, it does not excessively weaken the mechanical properties of the component body, and can withstand the vibration, impact and other stresses of the battery system during installation, transportation and operation, avoiding deformation or fracture of the component due to oversized grooves, which affects the overall sealing effect. At the same time, it is easy to process (such as through conventional processes such as milling, injection molding, etc.), and it is not easy to produce burrs, cracks and other defects during processing, ensuring smooth groove walls and reducing interference with the storage and release of self-healing adhesives.

[0048] As a preferred embodiment of the present application, referring to Figure 2 As shown in the figure, the spacing d between adjacent accommodation grooves 4 is 2-2.5 mm, and the adjacent accommodation grooves 4 are connected by flow guide grooves 6.

[0049] The spacing between the adjacent accommodation grooves 4 defined by the preferred embodiment can ensure the coverage of the self-healing adhesive 5, avoid the crack being in the repair blind area due to the too large spacing, and reduce the influence of the accommodation grooves 5 on the structural strength of the component 1 body through reasonable layout. For the common micro-cracks (mostly irregular expansion) of the battery sealing layer 3, the dense and spacing-optimized accommodation grooves 4 can ensure that the crack can quickly contact the repair material of at least one accommodation groove 4 during the expansion process, thereby shortening the repair response time.

[0050] The communication design of the flow guide groove 6 forms a cooperative repair network for the adjacent accommodation grooves 4. When the self-healing adhesive 5 of a certain accommodation groove 4 is consumed due to the repair of local cracks, the self-healing adhesive 5 of other accommodation grooves 4 can supplement it through the flow guide groove 6, thereby avoiding the repair failure caused by the exhaustion of the material of a single accommodation groove 4, especially suitable for dealing with longer or more branched cracks, and improving the repair coverage of the overall sealing layer 3. For example, when the crack spans multiple accommodation groove 4 areas, the flow guide groove 6 can guide the material to gather from multiple directions to the crack, thereby accelerating the crack filling speed. For the self-healing adhesive 5 (such as polyurethane / acrylate) that relies on the electrolyte to trigger, the flow guide groove 6 can promote the diffusion of the electrolyte between the accommodation grooves 4, so that the self-healing adhesive 5 of more accommodation grooves 4 can respond to the repair signal synchronously, thereby forming a multi-point starting and cooperative plugging effect, especially suitable for dealing with the initial multi-micro-crack scene of the sealing layer.

[0051] Further, as shown in Figure 1 and Figure 2 , the accommodation groove 4 is a cuboid groove with a rectangular cross section. As shown in Figure 3 , the cross section of the accommodation groove 4 is an inverted trapezoid. As shown in Figure 4 , the cross section of the accommodation groove 4 is a trapezoid.

[0052] As a preferred embodiment of the present application, as shown in Figure 1 , the thickness c of the sealing layer 3 is 3-5 mm.

[0053] The thickness of 3-5 mm provides sufficient structural strength and compression allowance for the sealing layer 3, which can tightly fit the contact surface of the component one (such as the battery frame) and the component two (such as the water cooling plate) through its own deformation, effectively block the electrolyte, coolant and external water vapor, and ensure the initial sealing effect. Moreover, the thickness of 3-5 mm will not cause the compression resistance to increase sharply during assembly, which is suitable for the compact installation space requirement of the battery system and avoids interference with the layout of adjacent components. In addition, the sealing layer with a thickness of 3-5 mm has a certain elastic buffering capacity, which can absorb the micro-displacement stress caused by temperature change and vibration during the operation of the battery, reduce the risk of direct rupture of the sealing layer caused by stress concentration, and reduce the probability of sealing failure from the source.

[0054] In an embodiment, the application provides a battery pack assembly comprising the self-repairing sealing structure described above.

[0055] As the core energy unit of new energy equipment, the sealing performance of the battery pack is directly related to the safety risks such as electrolyte leakage and thermal runaway. After integrating the self-repairing sealing structure, when the sealing layer of the battery frame and the water-cooled plate and other key parts is cracked due to impact, vibration, aging, etc., the self-repairing adhesive can actively repair (such as the polymerization reaction of DCPD microcapsules, the swelling and curing of polyurethane / acrylate, etc.) to seal in time, curb the leakage and diffusion from the source, avoid the corrosion and short circuit caused by the contact between the electrolyte and the external environment, or the temperature control failure caused by the leakage of the coolant, and significantly reduce the incidence of safety accidents. For the common micro-crack failure of the battery pack (which is difficult to detect by manual detection in the early stage), the self-repairing mechanism can realize the rapid response of "crack repair", making up for the lag of the traditional dependence on regular maintenance, and providing active protection for the battery pack all day long.

[0056] As a preferred embodiment of the application, it further comprises a battery frame and a water-cooled plate, the battery frame and the water-cooled plate are arranged with the self-repairing sealing structure described above, and the bottom surface of the battery frame is provided with a plurality of accommodation grooves for accommodating the self-repairing adhesive. The battery frame is made of aluminum alloy or sheet metal material.

[0057] In an embodiment, the application provides a vehicle comprising the battery pack assembly described above.

[0058] The vehicle can be, but is not limited to, a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), a new energy vehicle, etc.

[0059] The above embodiments are only preferred embodiments for fully illustrating the application, and the protection scope of the application is not limited thereto. Any equivalent replacement or transformation of the application based on the application is within the protection scope of the application.

Claims

1. A sealing structure with self-repairing function, characterized in that: The self-repairing sealing structure comprises a sealing layer (3) arranged between a first component (1) and a second component (2), the first component (1) is provided with a plurality of accommodating grooves (4) on one side close to the sealing layer (3), and the accommodating grooves (4) contain self-repairing adhesive (5), and the self-repairing adhesive (5) is released into the crack in response to the crack generated on the sealing layer (3) to cure and repair the crack.

2. The sealing structure with self-repairing function according to claim 1, characterized in that: The self-repairing adhesive (5) comprises a resin matrix and dicyclopentadiene microcapsules and ruthenium carbene catalyst uniformly dispersed in the resin matrix.

3. The sealing structure with self-repairing function according to claim 1, characterized in that: The self-repairing adhesive (5) comprises solid or semi-solid polyurethane or acrylate.

4. The sealing structure with self-repairing function according to claim 3, characterized in that: The groove wall of the accommodating groove (4) is coated with a nanoscale silica coating.

5. The self-repairing sealed structure according to claim 1, wherein: The depth a of the accommodating groove (4) is 1-1.5 mm, and the width b is 1.5-2.5 mm.

6. The self-repairing sealed structure according to claim 1, wherein: The spacing d between adjacent accommodating grooves (4) is 2-2.5 mm, and adjacent accommodating grooves (4) are connected by flow guide grooves (6).

7. The self-repairing sealed structure according to claim 1, wherein: The thickness c of the sealing layer (3) is 3-5 mm.

8. A battery pack assembly, characterized by: The self-repairing sealing structure according to any one of claims 1-7.

9. The battery pack assembly of claim 8, wherein: Further comprising a battery frame and a water-cooled plate, the battery frame and the water-cooled plate are arranged with the self-repairing sealing structure according to any one of claims 1-7, and the bottom surface of the battery frame is provided with a plurality of accommodating grooves for accommodating self-repairing adhesive.

10. A vehicle characterized by: The battery pack assembly according to claim 8 or 9. The battery pack assembly according to claim 8 or 9.

Images