Plastic assembly, connecting assembly and battery pack

Abstract

The utility model relates to a plastic assembly, a connecting assembly and a battery pack. The plastic assembly comprises a plastic base material layer and a polymer bonding conversion layer, the polymer bonding conversion layer is arranged on the first surface of the plastic base material layer; the surface, away from the plastic base material layer, of the polymer bonding conversion layer is used for being connected with a bonding agent. The plastic assembly can effectively solve the problem that bonding is difficult or the bonding performance of plastic parts with the bonding capacity to be improved is poor.

Description

Technical Field

[0001] The present disclosure relates to the technical field of plastic housings, and in particular, to a plastic assembly, a connection assembly, and a battery pack. Background Art

[0002] At present, the main methods to improve the surface bonding effect of difficult-to-bond parts are: (1) surface treatment of plastic parts or plastic materials; for example, simple surface cleaning, increasing surface roughness, and improving the surface energy of plastics in different ways; (2) for the purpose of good bonding of some special plastic materials, it is even necessary to develop special adhesives that are suitable for their characteristics.

[0003] Therefore, it is necessary to develop a method and structure to improve the bonding effect of difficult-to-bond plastic components in the battery system. Utility Model Content

[0004] The purpose of the present disclosure is to provide a plastic component, a connection component and a battery pack to effectively solve the problem of poor bonding performance of plastic parts that are difficult to bond or whose bonding ability needs to be improved.

[0005] In order to achieve the above-mentioned objectives, the first aspect of the present disclosure provides a plastic component, including a plastic substrate layer and a polymer bonding conversion layer; the polymer bonding conversion layer is arranged on the first surface of the plastic substrate layer; the surface of the polymer bonding conversion layer away from the plastic substrate layer is used for connecting with an adhesive.

[0006] Optionally, the polymer bonding conversion layer is a thermoplastic bonding conversion layer.

[0007] Optionally, the polymer adhesive conversion layer is selected from one of a polycarbonate adhesive conversion layer, a polyurethane adhesive conversion layer, a polyvinyl chloride adhesive conversion layer, an acrylonitrile-butadiene-styrene copolymer adhesive conversion layer, a polystyrene adhesive conversion layer, a polyethylene terephthalate adhesive conversion layer and a polybutylene terephthalate adhesive conversion layer.

[0008] Optionally, the thickness of the plastic substrate layer is 0.5 mm to 10 mm; and / or the thickness of the polymer adhesive conversion layer is 0.1 mm to 2 mm.

[0009] Optionally, the polymer bonding conversion layer is in the form of a board layer or a fabric layer.

[0010] Optionally, when the polymer bonding conversion layer is a fabric layer, the pores of the fabric layer further include adhesive fillers.

[0011] Optionally, the plastic component further comprises a transition layer; the transition layer is provided between the plastic substrate layer and the polymer adhesive conversion layer.

[0012] Optionally, the plastic component includes a first transition layer, which is arranged between the first surface of the plastic substrate layer and the polymer adhesion conversion layer; the first roughness Ra1 of the surface of the first transition layer in contact with the polymer adhesion conversion layer is 0.05μm~3.2μm; and / or the thickness of the first transition layer is 0.2μm~5μm.

[0013] Optionally, the plastic component includes a first transition layer and a second transition layer that are stacked; the first transition layer is disposed on the first surface of the plastic substrate layer; and the second transition layer includes an adhesive layer;

[0014] The second roughness Ra2 of the contact surface between the first transition layer and the second transition layer is 0.1 μm~6.4 μm; and / or the thickness of the first transition layer is 0.2 μm~10 μm, and / or the thickness of the second transition layer is 0.1 mm~1 mm.

[0015] The second aspect of the present disclosure provides a connecting component, comprising a first component, a first adhesive component, and a second component; the first adhesive component is arranged between the first component and the second component, the first component comprises the plastic component described in the first aspect of the present disclosure, and the polymer adhesive conversion layer of the plastic component is connected to the first adhesive component at a surface away from the plastic substrate layer.

[0016] A third aspect of the present disclosure provides a battery pack, which includes the plastic assembly described in the first aspect of the present disclosure.

[0017] Optionally, the battery pack includes a box, a part and a second adhesive component; the part is accommodated in the box, the part includes the plastic component described in the first aspect of the present disclosure, and the polymer adhesive conversion layer of the plastic component faces the outside of the part; the polymer adhesive conversion layer of the part is connected to the second adhesive component.

[0018] Through the above-mentioned technical solution, the present disclosure provides a plastic component, a connection component, and a battery pack. The plastic component includes a polymer bonding conversion layer disposed on the surface of a plastic substrate layer. Both surfaces of the polymer bonding conversion layer exhibit excellent wetting, adhesion, and bonding strength with the surface of the inner, difficult-to-bond plastic substrate layer and with the adhesive on the outer side. This allows the polymer bonding conversion layer to securely connect the previously difficult-to-bond plastic component surface to the adhesive, improving bonding performance. The bonding effect is long-lasting, ensuring that even if the plastic component is prepared before the PACK production line, it can still maintain excellent bonding performance during actual use on the PACK production line. Furthermore, the plastic component including the polymer bonding conversion layer can be used directly on the PACK production line, eliminating the need for specialized surface treatment processes (such as flame treatment, chemical etching, or surface activation, among other high-risk processes) to be integrated into the PACK production line. Standard adhesives can achieve easy bonding and high bonding strength. This significantly improves the mechanical performance and product consistency of the battery system product while simultaneously simplifying the PACK production process and increasing production cycle time. The plastic components provided by the present disclosure can be applied to a wide range of fields such as battery systems, electric vehicles and new energy vehicles. For example, application scenarios involving the optimization and improvement of the surface bonding effect of plastic parts can adopt the structure of the plastic components provided by the present disclosure, including but not limited to the bonding of foamed adhesives and plasticized wall panels in household appliances, refrigerated and insulated vehicles, the bonding of structural adhesives, other construction adhesives and plastic building decorative panels in the field of building decoration, and the improvement of the structural bonding of plastic interior parts in the traditional automotive field.

[0019] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0021] Figure 1 A schematic structural diagram of a plastic component provided by the present disclosure;

[0022] Figure 2 A schematic structural diagram of a plastic component provided by the present disclosure;

[0023] Figure 3 A schematic structural diagram of a plastic component provided by the present disclosure;

[0024] Figure 4 This is an exploded view of the battery pack.

[0025] Reference numerals

[0026] 1-Plastic substrate layer, 2-Polymer adhesive conversion layer, 3-First transition layer, 4-First transition layer, 5-Second transition layer; 401-Upper cover assembly, 402-CCS assembly, 403-Module assembly, 404-Lower box assembly, 405-Bottom guard plate structure. DETAILED DESCRIPTION

[0027] The following describes the specific embodiments of the present disclosure in detail. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0028] The inventors of the present disclosure have discovered that simple surface cleaning methods used in existing technologies cannot solve the bonding difficulties caused by the inherent lack of polar groups, low surface energy, high chemical inertness, and solvent resistance of plastic materials. Mechanical treatments to increase the surface roughness of plastic parts are not suitable for some thin-walled, brittle plastic materials. Plasma treatment, flame treatment, or chemical treatments (such as primers) to improve the bonding performance of plastic parts have been tested, but plasma treatment has shown inconsistent results on the surfaces of difficult-to-bond plastic parts. Furthermore, plasma cleaning has a short shelf life, with the bonding effect significantly declining after a certain period of time. Flame treatment and chemical treatments, because they involve open flames, flammable and explosive substances, and highly corrosive chemicals, cannot be integrated into battery system production lines. Therefore, these two plastic surface treatment methods cannot be used in battery system production. Specific adhesives have been developed for some difficult-to-bond plastic materials, but they are generally only effective for bonding a specific type of plastic, and their bonding effectiveness with other adherends is unknown. Furthermore, adhesives tailored for specific applications are typically used in small quantities and are generally expensive. In addition, the assembly, gluing, and bonding of plastic parts within the battery system are all completed on the PACK production line. Common plastic surface treatment methods, such as flame treatment and chemical treatment (such as primers), cannot be completed at the PACK assembly site, where open flames and chemical corrosive agents are strictly controlled. Instead, the surface treatment is completed by the component supplier before shipment and then transported to the on-site assembly site. However, due to the short-term effectiveness of surface treatment, the surface treatment effect during use may not be as expected.

[0029] A first aspect of the present disclosure provides a plastic component, such as Figure 1 As shown, it includes a plastic substrate layer 1 and a polymer adhesive conversion layer 2; the polymer adhesive conversion layer 2 is arranged on the first surface of the plastic substrate layer 1; the surface of the polymer adhesive conversion layer 2 away from the plastic substrate layer 1 is used to connect with the adhesive.

[0030] The present disclosure provides a plastic component having a polymer bonding conversion layer disposed on the surface of a plastic substrate layer. Both surfaces of the polymer bonding conversion layer exhibit excellent wetting, adhesion, and bonding strength with the surface of the inner, difficult-to-bond plastic substrate layer and with the adhesive on the outer side. This allows the previously difficult-to-bond plastic part surface to be securely connected to the adhesive via the polymer bonding conversion layer, improving bonding performance. The bonding effect is long-lasting, ensuring that even if the plastic component is prepared before the PACK production line, it can maintain excellent bonding performance during actual use on the PACK production line. Furthermore, the component is simple to use, eliminating the need for specialized surface treatment processes (such as flame treatment, chemical etching, or surface activation) integrated into the PACK production line. The plastic component including the polymer bonding conversion layer can be directly used in the PACK production line, achieving easy bonding and high bonding strength using standard adhesives. This significantly improves the mechanical performance and product consistency of battery system products while simultaneously simplifying the PACK production process and increasing production cycle time. The plastic components provided by the present disclosure can be applied to a wide range of fields such as battery systems, electric vehicles and new energy vehicles. For example, application scenarios involving the optimization and improvement of the surface bonding effect of plastic parts can adopt the structure of the plastic components provided by the present disclosure, including but not limited to the bonding of foamed adhesives and plasticized wall panels in household appliances, refrigerated and insulated vehicles, the bonding of structural adhesives, other construction adhesives and plastic building decorative panels in the field of building decoration, and the improvement of the structural bonding of plastic interior parts in the traditional automotive field.

[0031] In the present disclosure, the adhesive includes commonly used types, including but not limited to structural adhesive, foam adhesive, etc.

[0032] In a specific embodiment, the material of the plastic substrate layer mainly includes common thermoplastic materials such as PP (polypropylene), PA (polyamide, commonly known as nylon), PE (polyethylene) and their composite materials reinforced and modified by fibers, particles, etc., and also includes special plastics such as polytetrafluoroethylene (PTFE), fluoroplastics, polyimide (PI) and silicone system plastic materials.

[0033] In one embodiment, the polymer bonding conversion layer is a thermoplastic bonding conversion layer. The thermoplastic bonding conversion layer used in the present disclosure can have good adhesion, which is conducive to bonding with the plastic substrate layer.

[0034] In a preferred embodiment, the polymer adhesive conversion layer is selected from the group consisting of a polycarbonate adhesive conversion layer, a polyurethane adhesive conversion layer, a polyvinyl chloride adhesive conversion layer, an acrylonitrile-butadiene-styrene copolymer adhesive conversion layer, a polystyrene adhesive conversion layer, a polyethylene terephthalate adhesive conversion layer, and a polybutylene terephthalate adhesive conversion layer. The polymer adhesive conversion layer provided herein is made of materials such as ABS (acrylonitrile-butadiene-styrene copolymer), polyvinyl chloride (PVC), polycarbonate (PC), polystyrene (PS), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). These materials exhibit excellent wettability and adhesion to commonly used adhesives (e.g., structural adhesives) for plastic substrates and battery systems, achieving stable, high-strength bonding and maintaining long-term effectiveness. The polymer adhesive conversion layers used in this disclosure are all conventionally selected materials and can be purchased through common commercial channels or prepared using known methods.

[0035] In a specific embodiment, the thickness of the plastic substrate layer may be 0.5 mm to 10 mm, preferably 1 mm to 5 mm. The specific thickness of the plastic substrate layer may be selected based on the actual application of the plastic component. When the thickness of the plastic substrate layer is within the preferred range of this embodiment, the lightweight requirements of the battery system can be met.

[0036] And / or, the thickness of the polymer bonding conversion layer may be 0.1 mm to 2 mm, preferably 0.2 mm to 1 mm; on the premise of achieving the purpose of firmly connecting the plastic substrate layer and the adhesive, the thinner the polymer bonding conversion layer is, the better, so as to ensure a larger assembly space in the battery system.

[0037] In one embodiment, the polymer bonding conversion layer comprises a sheet or fabric layer. When the polymer bonding conversion layer is used in the form of a sheet, the polymer sheet can be joined to the difficult-to-bond plastic substrate layer through hot pressing or by bonding the polymer sheet to form a single unit. Alternatively, the plastic substrate layer can be pre-treated and then bonded using a special adhesive. Alternatively, easily bondable or adhesive-resistant plastic materials, such as polyester (PET), nylon (PA), polycarbonate (PC), and polyurethane (PU), can be formed into filaments of varying diameters through extrusion or thermoplastic drawing, and then woven into a "fabric." Such plastic filament fabrics are flexible or semi-flexible, and when bonded to the difficult-to-bond plastic substrate layer, they generate lower stress and have higher porosity and surface roughness. The fabric-like polymer bonding conversion layer can be joined to the difficult-to-bond plastic substrate layer similarly to the sheet, such as through hot pressing or bonding using a "pre-treatment + special adhesive" method. When gluing is used, adhesives with lower viscosity can penetrate into the pores of the fabric-like "conversion layer", resulting in a larger bonding surface area. The warp and weft mesh of the fabric is equivalent to "rebar" and the adhesive is equivalent to "concrete", making the bonding of the imitation architectural form more reliable.

[0038] In the present disclosure, the temperature for hot melt pressing between the polymer bonding conversion layer and the plastic substrate layer can be set according to the specific melting temperature of the material used for the polymer bonding conversion layer and the material of the plastic substrate layer. Optionally, the temperature range of hot melt pressing can be 100°C~230°C.

[0039] In one specific embodiment, the melting temperature of the polycarbonate adhesive conversion layer is 215°C to 225°C; the melting temperature of the polyurethane adhesive conversion layer is 170°C to 190°C; the melting temperature of the polyvinyl chloride adhesive conversion layer is 170°C to 190°C; the melting temperature of the acrylonitrile-butadiene-styrene copolymer adhesive conversion layer is 180°C to 250°C; the melting temperature of the polystyrene adhesive conversion layer is 150°C to 180°C; the melting temperature of the polyethylene terephthalate adhesive conversion layer is 250°C to 260°C; and the melting temperature of the polybutylene terephthalate adhesive conversion layer is 220°C to 230°C. Among the materials for the plastic substrate layer to be improved listed in this disclosure: low-density polyethylene (LDPE) has a melting temperature range of approximately 105°C to 115°C; polypropylene (PP) has a melting temperature of approximately 160°C to 175°C; and polyamide PA6 has a melting temperature of approximately 215°C to 225°C. The temperature range of the hot melt pressing process requires comparative evaluation of the melting temperatures of the two thermoplastic plastics, the plastic substrate layer and the polymer adhesive conversion layer, and the melting temperature of the plastic material with the lower temperature is taken as the temperature range of the hot pressing composite.

[0040] In one specific embodiment, when the polymer bonding conversion layer is a fabric layer, the pores of the fabric layer also include adhesive fillers. That is, when bonding is performed using the aforementioned adhesive method, the pores of the fabric layer are filled with adhesive fillers. The bottom adhesive in the pores, together with the remaining height of the easy-to-bond fabric layer, can further enhance the bonding effect of the general adhesive used when connecting the plastic component to other plastic materials.

[0041] In a preferred embodiment, the plastic component further includes a transition layer disposed between the plastic substrate layer and the polymer bonding conversion layer. The provision of the transition layer allows the polymer bonding conversion layer to be more firmly fixed to the first surface of the plastic substrate layer, thereby improving the bonding strength. The implementation process for this transition layer may include: flame treating the first surface of the plastic substrate layer, chemically etching (surface coating treatment), and texturizing the plastic body (plastic substrate layer). The texturizing treatment improves the surface roughness or surface energy of the optimized first surface of the plastic substrate layer, thereby providing a better connection to the polymer bonding conversion layer. The textured first surface of the plastic substrate layer is then coated with a specialized adhesive, thereby connecting the polymer bonding conversion layer to the polymer bonding conversion layer. Alternatively, the polymer bonding conversion layer may be connected to the polymer bonding conversion layer by friction welding, ultrasonic welding, hot melt pressing, or mechanical connection methods such as snap-fitting, screwing, or riveting.

[0042] In a specific embodiment, the number of transition layers can be 0; when a cold mechanical connection method (clip, screw and rivet) is used to fix the plastic substrate layer and the polymer adhesive conversion layer, the number of transition layers is defined as 0, that is, no intermediate transition layer exists.

[0043] In another specific embodiment, Figure 2 As shown, the plastic assembly includes a first transition layer 3 (i.e., one transition layer). The first transition layer 3 is disposed between the first surface of the plastic substrate layer 1 and the polymer bonding conversion layer 2. The bonding strength between the first transition layer 3 and the polymer bonding conversion layer 2, as well as the bonding strength between the first transition layer 3 and the first surface of the plastic substrate layer 1, is significantly higher than the bonding strength when the first surface of the plastic substrate layer 1 is directly bonded to the polymer bonding conversion layer 2. When hot melt welding, friction welding, ultrasonic welding, diffusion welding, or bonding using only a specific adhesive is employed, the number of transition layers is defined as one. The first transition layer can be obtained by surface treating the first surface of the plastic substrate layer. The surface treatment method can be conventional in the art. The provision of the first transition layer enhances the bonding strength between the polymer bonding conversion layer and the first surface of the plastic substrate layer. The first transition layer is fabricated at the plastic component supplier, unaffected by fire and chemical prohibitions. This allows for a wider range of methods to enhance bonding strength than in the battery system production workshop.

[0044] In a specific embodiment, the first roughness Ra1 of the surface of the first transition layer in contact with the polymer bonding conversion layer is 0.05μm~3.2μm, preferably 0.4μm~3.2μm. The surface roughness of the conventionally used plastic substrate layer is relatively low, Ra is about 0.012μm~1.6μm; and the first roughness Ra1 of the first transition layer obtained after the surface of the plastic substrate layer is surface treated is increased. When Ra1 is within the range of this embodiment, especially within the preferred range, the surface of the first transition layer has a greater roughness, which is beneficial to improving the fixing strength between the first transition layer and the polymer bonding conversion layer; and / or, the thickness of the first transition layer is 0.2μm~5μm, preferably 1~3μm. The first transition layer provided in the present disclosure has an appropriate thickness, which can avoid the disadvantage of difficult control of product stability due to excessively thin thickness.

[0045] In another specific embodiment, Figure 3 As shown, the plastic component includes a first transition layer 4 and a second transition layer 5 (i.e., the number of transition layers is 2) arranged in a stacked manner; the first transition layer 4 is arranged on the first surface of the plastic substrate layer 1, wherein the fixing strength between the first transition layer 4 and the second transition layer 5, as well as the fixing strength between the first transition layer and the first surface of the plastic substrate layer, are significantly higher than the fixing strength between the plastic substrate layer and the polymer adhesive conversion layer when directly connected or connected using only one transition layer (e.g., using only the first transition layer); the second transition layer 5 includes an adhesive layer. When the surface of the plastic substrate layer is treated as a pretreatment means by surface energy activation methods such as flame treatment and chemical etching (surface coating treatment), and then the polymer adhesive conversion layer is bonded to the pretreated activated surface by a special adhesive, the number of transition layers is 2, i.e., the pretreatment layer is the first layer (e.g., Figure 3 In addition to the first transition layer 4 in the embodiment, the bonding layer (e.g., a dedicated adhesive layer) that forms the actual connection strength is the second transition layer 5. The provision of the first and second transition layers 4 and 5 effectively enhances the fixing strength between the polymer adhesive conversion layer and the first surface of the plastic substrate layer.

[0046] In a specific embodiment, the second roughness Ra2 of the surface in contact between the first transition layer 4 and the second transition layer 5 is 0.1 μm to 6.4 μm, preferably 0.4 μm to 6.4 μm. Increasing the roughness is beneficial to improving the fixing strength between the second transition layer and the polymer adhesive conversion layer.

[0047] And / or, the thickness of the first transition layer is 0.2 μm to 10 μm, preferably 1 μm to 5 μm, which can eliminate the disadvantage of the first transition layer being too thin to control the stability of the product; and / or, the thickness of the second transition layer is 0.1 mm to 1 mm, preferably 0.2 mm to 0.6 mm, the second transition layer (i.e. the adhesive layer) with the thickness in the embodiment can have a higher bonding strength.

[0048] In the present disclosure, the transition layer can be formed by the following ways:

[0049] (1) Flame treatment: ① Before flame treatment on the first surface of the plastic substrate layer, the surface to be bonded (i.e. the first surface) is pre-cleaned to remove impurities such as oil, dust, release agent, etc.; ② Isopropyl alcohol or special plastic cleaner is used during the above surface cleaning, and natural drying or heating drying is required before flame treatment; ③ Flame parameter adjustment, adjust the flame intensity, temperature and mixing ratio of gas and air according to the type and thickness of the plastic, different plastics have different tolerance to flame, for example, polyolefin plastics usually need strong flame, while heat-sensitive plastics need relatively weak flame; ④ Flame treatment process requirements, during the flame treatment process, the flame should uniformly cover the entire surface of the plastic part to be treated; the flame treatment time on the surface of the plastic part is usually several seconds to tens of seconds, and attention should be paid to avoid over-treatment; ⑤ Surface requirements after flame treatment: the appearance and size change of the plastic substrate layer is within the acceptable range, and the surface energy / surface tension range is usually 36-48 mN / m; in addition, the surface roughness of the plastic substrate layer after flame treatment will also change, usually in the range of Ra 0.5 μm to 2.0 μm. In the above flame treatment state, the gluing and bonding or hot pressing of the transition layer integrally formed on the first surface of the plastic substrate layer has good effect.

[0050] (2) Chemical treatment (surface coating agent or etching treatment) on the surface of the plastic part: the chemical treatment methods and processes of different plastic materials have great differences, but the purpose is the same: to remove contaminants on the surface of the plastic part, to improve the surface energy or surface tension of the difficult-to-bond plastic part, to improve the surface roughness of the plastic part, or even to form new surface chemical bonds such as covalent bonds and ionic bonds. For polyolefin plastic substrate layer, the main chemical treatment reagents are chromium sulfate and persulfate; and for fluorine plastic substrate layer, the main chemical treatment methods are chlorosulfonation and sodium-naphthalene corrosion. Regarding the requirements of the surface of the plastic substrate layer after chemical treatment, the plastic surface should not be left with harmful components in the treatment agent after chemical treatment, the treated plastic surface should be uniform at the micro and macro levels, and the plastic surface should have sufficient activity to produce good adhesion with the adhesive, or meet the surface energy requirements of other fixing methods of the conversion layer.

[0051] (3) Mechanically treat the surface of the plastic part to increase the surface roughness, thereby increasing the macro / micro contact area of ​​the two interfaces (including the interface between the first surface of the plastic substrate layer and the polymer bonding conversion layer, or the interface between the first transition layer obtained by mechanical treatment and the subsequent second transition layer). Common mechanical treatment methods include: sandblasting, grinding, tumbling, embossing, and mechanical cutting, which can be performed using conventional operations in this field. The following points should be noted when using the above-mentioned mechanical methods to increase the surface roughness of plastic parts: according to the strength and hardness of the plastic substrate, the thickness of the part, and the target surface roughness, select the appropriate grinding tool mesh and the corresponding processing pressure or equipment speed to prevent excessive grinding, sandblasting, etc. from causing deep grooves or pits on the surface of the plastic part, which will affect the strength and introduce new stress concentration points. After mechanical surface roughening, the surface of the plastic part must be thoroughly cleaned to remove debris, dust, and possible residual oil and other impurities generated by the mechanical treatment, otherwise it will affect the bonding or composite strength of the "conversion layer" or "transition layer" above it. The process of setting the transition layer in this disclosure is completed before the PACK production line.

[0052] A second aspect of the present disclosure provides a connection assembly comprising a first component, a first adhesive component, and a second component; the first adhesive component is disposed between the first and second components, the first component comprising the plastic component described in the first aspect of the present disclosure, and the surface of the polymer adhesive conversion layer of the plastic component remote from the plastic substrate layer is connected to the first adhesive component. The second component of the present disclosure for connection to the plastic component can be made of a conventional material in the battery pack field. In this connection assembly, the polymer adhesive conversion layer can improve the ease of connection and bonding strength between the first and second components.

[0053] A third aspect of the present disclosure provides a battery pack, which includes the plastic assembly described in the first aspect of the present disclosure.

[0054] like Figure 4As shown, a conventional battery pack primarily comprises: an upper cover assembly 401, a CCS assembly 402, a module assembly 403, and a lower case assembly 404. In addition to the regularly stacked battery cells, module assembly 403 also integrates a liquid cooling system (such as a liquid cooling plate, current collector, and liquid cooling pipe joints, not shown in the exploded view). Lower case assembly 404 also includes a bottom guard plate structure 405, which is typically integrated into the frame around the case and located at the very bottom of the battery pack. Currently, as battery packs become lighter and higher voltage, the primary structural components of the battery pack are the upper cover and bottom guard plate, along with other smaller components such as module support plates, isolation plates, and module beading. High-strength plastics are often used instead of traditional metal parts. Taking the upper cover assembly and underbody guard as an example, large structural parts such as the upper cover assembly and underbody guard are usually made of thermoplastic plastic substrates such as polypropylene (PP) and nylon (PA), with PP being the main material. At the same time, in order to improve the strength of the plastic body, glass fiber or other fiber materials are used for reinforcement. The body strength of the reinforced plastic composite material can approach or even exceed the strength of 6 series extruded aluminum profiles, thus replacing traditional metal parts. In addition, when thermoplastic plastic parts are bonded with conventional adhesives in the battery pack (such as polyurethane structural adhesive, polyurethane foam adhesive, modified epoxy structural adhesive, hybrid system structural adhesive, etc.), they cannot achieve a good bonding effect. The bonding strength is significantly lower than the strength of the plastic part parent material, structural adhesive or foam adhesive parent material itself, showing obvious interfacial damage. Under normal circumstances, the bonding strength of the same structural adhesive to the surface of materials such as PP and PA mentioned above is only equivalent to 1 / 5 to 1 / 3 of the bonding strength to the electrophoretic layer or aluminum alloy surface. Because the top cover and bottom guard plate are the main load-bearing components of the battery pack, they are bonded together using structural adhesive or thermally conductive adhesive to secure the module and liquid cooling system. However, this approach is not suitable for sandwich-structured battery packs (such as CTC and CTB battery pack designs) that rely heavily on adhesive for bonding. The present disclosure provides a plastic assembly for use in battery packs, enabling a secure and long-lasting connection with the adhesive encapsulated within the battery pack.

[0055] In one specific embodiment, the battery pack includes a housing, a component, and a second adhesive component. The component is housed in the housing, and the component includes the plastic component described in the first aspect of this disclosure, with the polymer adhesive conversion layer of the plastic component facing the exterior of the component. The polymer adhesive conversion layer of the component is connected to the second adhesive component. In this disclosure, the polymer adhesive conversion layer on the exterior of the component can be tightly bonded to the battery pack housing using conventional adhesive components (e.g., structural adhesive, foam adhesive, etc.). This allows for a secure and long-lasting connection between difficult-to-bond plastic component substrates, as well as between the plastic component substrate and the battery pack housing.

[0056] According to the present disclosure, parts such as the upper cover, end plates, bottom plate, and cable harness separator (CCS) are connected to other components using adhesives to enhance the strength of the connections. Furthermore, while the battery pack is filled with adhesive to enhance its strength, adding a polymer adhesive conversion layer can further enhance the overall connection strength, further improving the overall strength of the battery pack.

[0057] The present disclosure is further described in detail below through examples.

[0058] In the following embodiments, the polymer bonding conversion layer is a polyethylene terephthalate (PET) bonding conversion layer, and its melting temperature is 250°C~260°C; and the polymer bonding conversion layer is in the form of a fabric layer (i.e., a fiber cloth made of PET material); the material of the plastic substrate layer is PP (polypropylene) plastic containing glass fiber (GF), and its melting temperature range is 160°C~175°C; the hot melt pressing temperature of the plastic substrate layer and the polymer conversion layer can be set to 170°C~185°C.

[0059] Example 1

[0060] This embodiment provides a plastic component, such as Figure 1 As shown, it includes a plastic substrate layer 1 and a polymer bonding conversion layer 2; the polymer bonding conversion layer 2 is arranged on the first surface of the plastic substrate layer 1; the surface of the polymer bonding conversion layer 2 away from the plastic substrate layer 1 is used for bonding with the structural adhesive; the thickness of the plastic substrate layer 1 is 2 mm; the thickness of the polymer bonding conversion layer 2 is 1 mm.

[0061] Example 2

[0062] This embodiment provides a plastic component, such as Figure 2 As shown, it includes a plastic substrate layer 1, a polymer adhesive conversion layer 2 and a first transition layer 3; the first transition layer 3 is provided between the plastic substrate layer 1 and the polymer adhesive conversion layer 2, and the first transition layer 3 is integrally formed on the first surface of the plastic substrate layer 1;

[0063] The surface roughness of the first transition layer 3 in contact with the polymer adhesion conversion layer 2 is higher, making the connection between the first transition layer 3 and the polymer adhesion conversion layer 2 more secure; the first roughness Ra1 of the surface in contact with the polymer adhesion conversion layer 2 is 0.8 μm; the thickness of the plastic substrate layer 1 is 2.5 mm; the thickness of the polymer adhesion conversion layer 2 is 1 mm, and the thickness of the first transition layer 3 is 2 μm.

[0064] Example 3

[0065] This embodiment provides a plastic component, such as Figure 3As shown, the plastic component comprises a plastic substrate layer 1 and a polymer adhesive conversion layer 2; the polymer adhesive conversion layer 2 is arranged on the first surface of the plastic substrate layer 1; the plastic component further comprises a first transition layer 4 and a second transition layer 5 arranged in a stack, the first transition layer 4 and the second transition layer 5 are arranged between the plastic substrate layer 1 and the polymer adhesive conversion layer 2; the first transition layer 4 is arranged on the first surface of the plastic substrate layer 1, and the surface of the first transition layer 4 and the second transition layer 5 in contact has a higher roughness to improve the bonding strength; the second transition layer 5 comprises an adhesive layer;

[0066] The second roughness Ra2 of the surface of the first transition layer 4 and the second transition layer 5 in contact is 1.6 μm, the thickness of the plastic substrate layer 1 is 3 mm; the thickness of the polymer adhesive conversion layer 2 is 0.5 mm, the thickness of the first transition layer 4 is 3 μm, and the thickness of the second transition layer 5 is 0.4 mm.

[0067] The above describes the preferred embodiments of the present disclosure in detail, but the present disclosure is not limited to the specific details in the above embodiments, and within the technical concept range of the present disclosure, the technical solutions of the present disclosure can be variously modified, and these simple modifications all belong to the protection range of the present disclosure.

[0068] In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present disclosure will not further describe various possible combination manners.

[0069] In addition, the various different embodiments of the present disclosure can also be combined in any manner, as long as it does not deviate from the idea of the present disclosure, it should also be considered as disclosed by the present disclosure.

Claims

1. A plastic component, characterized in that: The invention comprises a plastic substrate layer and a polymer adhesive conversion layer; the polymer adhesive conversion layer is arranged on a first surface of the plastic substrate layer; and the surface of the polymer adhesive conversion layer away from the plastic substrate layer is used for connecting with an adhesive.

2. The plastic component according to claim 1, wherein: The polymer bonding conversion layer is a thermoplastic bonding conversion layer.

3. The plastic component according to claim 1, wherein: The polymer adhesive conversion layer is selected from one of a polycarbonate adhesive conversion layer, a polyurethane adhesive conversion layer, a polyvinyl chloride adhesive conversion layer, an acrylonitrile-butadiene-styrene copolymer adhesive conversion layer, a polystyrene adhesive conversion layer, a polyethylene terephthalate adhesive conversion layer and a polybutylene terephthalate adhesive conversion layer.

4. The plastic component according to claim 1, wherein: The thickness of the plastic substrate layer is 0.5 mm to 10 mm; and / or the thickness of the polymer adhesive conversion layer is 0.1 mm to 2 mm.

5. The plastic component according to claim 1, wherein: The polymer bonding conversion layer may be in the form of a sheet layer or a fabric layer.

6. The plastic component according to claim 5, characterized in that When the polymer adhesive conversion layer is a fabric layer, the pores of the fabric layer further include adhesive fillers.

7. The plastic component according to claim 1, wherein: The plastic component further comprises a transition layer; the transition layer is arranged between the plastic substrate layer and the polymer adhesive conversion layer.

8. The plastic component according to claim 7, wherein: The plastic component includes a first transition layer, which is arranged between the first surface of the plastic substrate layer and the polymer adhesion conversion layer; the first roughness Ra1 of the surface of the first transition layer in contact with the polymer adhesion conversion layer is 0.05μm~3.2μm; and / or the thickness of the first transition layer is 0.2μm~5μm.

9. The plastic component according to claim 7, wherein: The plastic component comprises a first transition layer and a second transition layer which are stacked; the first transition layer is arranged on the first surface of the plastic substrate layer; the second transition layer comprises an adhesive layer; The second roughness Ra2 of the contact surface between the first transition layer and the second transition layer is 0.1 μm~6.4 μm; and / or the thickness of the first transition layer is 0.2 μm~10 μm, and / or the thickness of the second transition layer is 0.1 mm~1 mm.

10. A connection assembly, characterized in that: It includes a first component, a first adhesive component and a second component; the first adhesive component is arranged between the first component and the second component, the first component includes the plastic component according to any one of claims 1 to 9, and the polymer adhesive conversion layer of the plastic component is connected to the first adhesive component at a surface away from the plastic substrate layer.

11. A battery pack, characterized in that: The invention comprises a plastic component as described in any one of claims 1 to 9.

12. The battery pack according to claim 11, wherein: The battery pack includes a box, a part, and a second bonding component; the part is accommodated in the box, the part includes the plastic component, and the polymer bonding conversion layer of the plastic component faces the outside of the part; The polymer adhesive conversion layer of the component is connected to the second adhesive component.

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