A PEEK-based composite modified material, a cell shell / packaging structure and a preparation method thereof, and an assembling component and an assembling method of a power battery cell

Abstract

The application provides a PEEK-based composite modified material, a cell shell / encapsulation structure and a preparation method thereof, and an assembling component and an assembling method of a power battery cell, the PEEK-based composite modified material comprises the following raw materials in mass fraction: PEEK resin 80%-85%, carbon fiber 10%-12%, Al2O3 ceramic particles 3%-5%, anti-aging agent 0.5%-1%, and compatible agent 1%-2%. The toughness, thermal conductivity and corrosion resistance of the material are improved by adding carbon fiber and Al2O3 ceramic particle modified fillers to perform composite modification on the PEEK resin; the cell shell / encapsulation structure is designed to be suitable for the size and use requirement of the square and soft package cells of the power battery, the buffering and heat insulation integrated details are additionally arranged, and the assembling mode is optimized, so that the integration of the material modification, structure optimization and encapsulation adaptation is realized, and the safety, lightweight level and service life of the power battery are improved.

Description

Technical Field

[0001] This invention relates to the field of power battery technology, and more specifically, to a PEEK-based composite modified material, a cell casing / packaging structure and its preparation method, and an assembly assembly for a power battery cell and its assembly method. Background Technology

[0002] With the rapid upgrading of the new energy vehicle industry, power batteries, as the core power supply component for pure electric vehicles and hybrid electric vehicles, directly determine the driving safety, range, and market competitiveness of new energy vehicles through their safety performance, lightweighting level, and service life. The cell casing / encapsulation structure, as the core protective component of the power battery cell, is mainly used to isolate the cell from the external environment, protect the internal structure of the cell, prevent electrolyte leakage, and prevent damage to the cell from external impacts. Its performance directly affects the overall safety and service life of the power battery.

[0003] GB 38031, "Safety Requirements for Power Batteries for Electric Vehicles," clearly stipulates that power batteries must possess excellent high-temperature resistance, impact resistance, and leak-proof performance. Simultaneously, the market's increasing demand for extended driving range in new energy vehicles necessitates lightweight design for power battery packs to reduce overall vehicle energy consumption. Therefore, developing a power battery cell casing / packaging structure that combines high-temperature resistance, chemical corrosion resistance, excellent insulation, high mechanical strength, and lightweight design has become a core requirement urgently needing to be addressed in the current battery system technology field.

[0004] Polyetheretherketone (PEEK) is a high-performance special engineering plastic with a long-term service temperature above 250℃, resistance to chemical corrosion (resistant to battery electrolyte erosion), and excellent insulation properties (insulation resistance ≥10 Ω·cm). 12 Ω), high mechanical strength (tensile strength ≥130MPa), lightweight (density 1.3-1.4g / cm³). 3 With its core characteristics such as good flame retardancy, PEEK material is theoretically suitable for the performance requirements of power battery cell casing / packaging structures. However, the application of PEEK material in the field of power battery cell casing / packaging structures is still a blank. Existing technologies mostly use conventional materials, which cannot fully utilize the advantages of PEEK material and are difficult to meet the stringent usage requirements of power batteries.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a PEEK-based composite modified material, a cell casing / packaging structure and its preparation method, and an assembly component and assembly method for power battery cells. Utilizing the core characteristics of polyetheretherketone (PEEK) material—high temperature resistance, chemical corrosion resistance, excellent insulation, high mechanical strength, and lightweight—this invention modifies PEEK resin by adding carbon fiber and Al2O3 ceramic particles as fillers, optimizing the material formulation and preparation process to improve the material's toughness, thermal conductivity, and corrosion resistance. Simultaneously, considering the external dimensions and usage requirements of square and pouch cells for power batteries, a suitable cell casing / packaging structure is designed, incorporating integrated buffering and heat insulation details, and optimizing the assembly method. This achieves an integrated approach of "material modification - structural optimization - packaging adaptation," solving the core technical defects of existing cell casing / packaging structures such as "the inability to simultaneously achieve lightweight and safety, susceptibility to high-temperature failure, and poor corrosion resistance," thereby improving the safety, lightweight level, and service life of power batteries.

[0007] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A PEEK-based composite modified material for use in battery cell casing / packaging structure, comprising the following raw materials by mass fraction: 80%-85% PEEK resin, 10%-12% carbon fiber, 3%-5% Al2O3 ceramic particles, 0.5%-1% anti-aging agent, and 1%-2% compatibilizer.

[0008] Furthermore, the length of the carbon fiber is 5-10 μm.

[0009] Furthermore, the particle size of the Al2O3 ceramic particles is 100-500 nm.

[0010] Furthermore, the anti-aging agent includes at least one of hindered phenols, phosphites, and thioethers.

[0011] Furthermore, the compatibilizer is a maleic anhydride-grafted PEEK compatibilizer, and the grafting rate of the maleic anhydride-grafted PEEK compatibilizer is 0.2%-1.0%.

[0012] The preparation method of the above-mentioned PEEK-based composite modified material includes the following steps: Step 1, Mixing: Add PEEK resin, carbon fiber, Al2O3 ceramic particles, anti-aging agent, and compatibilizer in proportion, and mix evenly at a temperature of 80-100℃; Step 2, melt extrusion and granulation: Extrusion temperature 380-400℃, followed by granulation; Step 3, Drying: The granulated particles are vacuum dried at a temperature of 120-150℃ to obtain PEEK-based composite modified particles.

[0013] A method for preparing a PEEK-based composite modified material battery cell shell / packaging structure, wherein the battery cell shell / packaging structure is prepared by injection molding or compression molding using the above-mentioned PEEK-based composite modified material or the PEEK-based composite modified material prepared by the above-mentioned method. The injection molding process is as follows: injection temperature 390-410℃, mold temperature 120-150℃, injection pressure 50-80MPa, holding time 10-15s, and then removed after cooling and molding. The molding process is as follows: molding temperature 390-410℃, molding pressure 70-100MPa, holding time 15-50s, and then removed after cooling and molding.

[0014] An assembly assembly for a power battery cell includes a cell shell / encapsulation structure made of PEEK-based composite modified material prepared by the above-described preparation method.

[0015] Furthermore, the battery cell casing / packaging structure is generally a cuboid box shape or a thin packaging structure.

[0016] Furthermore, the thickness of the cell casing / packaging structure is 2-3 mm.

[0017] Furthermore, a packaging port is provided on the top of the cell casing / packaging structure.

[0018] Furthermore, the inner wall of the cell casing / encapsulation structure and the edge of the encapsulation opening are coated with an insulating coating with a thickness of 0.4-0.6 mm.

[0019] Furthermore, a buffer layer with a thickness of 1-2 mm is provided on the inner wall of the battery cell casing / encapsulation structure.

[0020] Furthermore, a positioning protrusion is provided at the bottom of the cell housing / packaging structure, and a buckle is provided on the side of the cell housing / packaging structure.

[0021] Furthermore, a sealing groove is provided at the edge of the encapsulation opening, and a sealing ring is embedded in the sealing groove.

[0022] Furthermore, reinforcing ribs are provided on the bottom and sides of the cell casing / packaging structure.

[0023] Furthermore, the diameter of the sealing ring cross-section is 3-5 mm.

[0024] Furthermore, the spacing between the reinforcing ribs is 30-50mm, and the thickness of the reinforcing ribs is 1-1.5mm.

[0025] The assembly method of the above-mentioned power battery cell assembly assembly is to assemble the power battery cell outside. The assembly method includes: inserting the cell into the encapsulation port of the cell shell / encapsulation structure, fixing the cell after positioning; embedding a sealing ring in the sealing groove, and completing the encapsulation using a thermo-pressing encapsulation process.

[0026] Furthermore, the hot-pressing encapsulation process conditions are: hot-pressing temperature 150-180℃, hot-pressing pressure 10-15MPa, and hot-pressing time 3-5min.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The PEEK-based composite modified material cell casing / encapsulation structure of this invention can significantly improve high-temperature resistance: the long-term operating temperature can reach above 250℃, and the short-term temperature can withstand 300℃. Compared with existing PC / ABS plastic casings, the high-temperature resistance is improved by more than 60%. Compared with aluminum alloy casings, it can effectively cope with the high-temperature environment in the early stage of thermal runaway. It can improve the safety of power batteries: effectively avoid safety hazards such as leakage, short circuit, and electrolyte leakage caused by high-temperature failure, corrosion damage, and insufficient insulation of the casing, reduce the risk of battery thermal runaway, and improve the safety of power battery use.

[0028] 2. The PEEK-based composite modified material of this invention exhibits outstanding lightweighting effect in the cell casing / packaging structure: the density of the cell casing / packaging structure is controlled at 1.4-1.5 g / cm³. 3 Compared with existing aluminum alloy shells of the same specifications, the weight is reduced by 30%-40%, which can effectively reduce the overall weight of the power battery pack and help improve the range of new energy vehicles by 10%-15%.

[0029] 3. The PEEK-based composite modified material of this invention exhibits excellent overall performance in the cell casing / packaging structure: insulation resistance ≥10 Ω·cm. 12 Ω, exhibits excellent resistance to electrolyte corrosion, showing no cracking or deformation after immersion in electrolyte for 72 hours; tensile strength ≥150MPa, impact strength ≥80kJ / m 2 It has strong resistance to compression, meeting the stringent protection requirements of power batteries; it can effectively extend the service life of batteries: PEEK-based composite modified materials have excellent aging resistance and corrosion resistance, which can extend the service life of the cell shell / encapsulation structure by more than 20%, thereby extending the overall service life of the power battery.

[0030] 4. The assembly components of the power battery cells of this invention have strong assembly compatibility: they can be directly adapted to existing square and soft-pack cell specifications and power battery assembly processes, without the need for additional production equipment, reducing production costs and facilitating industrial mass production; they can be adapted to diverse scenarios: they can meet the usage requirements under complex working conditions such as high-rate charging and discharging, high temperature, and high humidity, and are compatible with various square and soft-pack power cells for pure electric vehicles and hybrid electric vehicles, while also being compatible with power batteries for outdoor energy storage.

[0031] 5. This invention possesses economic and industry value, with controllable costs: The optimized formulation of the PEEK-based composite modified material reduces the amount of PEEK resin used, while simplifying the shell structure design (eliminating the need for additional insulation and heat insulation layers), reducing assembly processes, and lowering the total production cost; it promotes industry upgrading: filling the application gap of PEEK materials in the field of power battery cell shell / packaging structure, providing a new material solution for lightweight, high-safety, and long-life power batteries, promoting the technological upgrading of new energy vehicle battery systems, and possessing broad prospects for industrial application. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0033] A PEEK-based composite modified material for use in battery cell casing / packaging structure, comprising the following raw materials by mass fraction: 80%-85% PEEK resin, 10%-12% carbon fiber, 3%-5% Al2O3 ceramic particles, 0.5%-1% anti-aging agent, and 1%-2% compatibilizer.

[0034] In the PEEK-based composite modified material of the present invention, the PEEK resin has excellent high temperature resistance, corrosion resistance and insulation properties, and serves as the matrix material of the composite modified material; the carbon fiber and the Al2O3 ceramic particles serve as modified fillers; and the anti-aging agent and compatibilizer serve as auxiliary materials.

[0035] In some embodiments, the carbon fiber has a length of 5-10 μm (including but not limited to 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm), and the carbon fiber is used as a modified filler to improve the mechanical strength and lightweight effect of the material.

[0036] In some embodiments, the particle size of the Al2O3 ceramic particles is 100-500nm (including but not limited to 100nm, 200nm, 300nm, 400nm, and 500nm), and the Al2O3 ceramic particles are used as modified fillers to improve the high-temperature resistance and wear resistance of the material.

[0037] In some embodiments, the anti-aging agent includes at least one of hindered phenols, phosphites, and thioethers to improve the aging resistance of the material.

[0038] In some embodiments, the compatibilizer is a maleic anhydride-grafted PEEK compatibilizer with a grafting rate of 0.2%-1.0%, which improves the compatibility between PEEK resin and modified fillers (carbon fiber and Al2O3 ceramic particles) and avoids delamination.

[0039] This invention relates to a PEEK-based composite modified material, proposing a PEEK-based composite modified material formulation adapted to the shell / packaging structure of power battery cells. Through precise proportioning of PEEK resin, carbon fiber, and Al2O3 ceramic particles and composite modification process, the problem of insufficient toughness and thermal conductivity of single PEEK material is solved. At the same time, it achieves a synergistic effect of multiple properties such as high temperature resistance, corrosion resistance, insulation, high strength, and lightweight, filling the application gap of PEEK material in this field.

[0040] The preparation method of the above-mentioned PEEK-based composite modified material includes the following steps: Step 1, Mixing: Add PEEK resin, carbon fiber, Al2O3 ceramic particles, anti-aging agent, and compatibilizer in proportion, and mix evenly at a temperature of 80-100℃ (including but not limited to 80℃, 85℃, 90℃, 95℃, and 100℃). Step 2, melt extrusion and granulation: Extrusion temperature 380-400℃ (including but not limited to 380℃, 385℃, 390℃, 395℃, 400℃), followed by granulation; Step 3, Drying: Vacuum dry the granulated particles at a temperature of 120-150℃ (including but not limited to 120℃, 130℃, 140℃, 150℃) to obtain PEEK-based composite modified particles.

[0041] In some embodiments, step 1 involves mixing by stirring at a speed of 300-500 r / min (including but not limited to 300 r / min, 350 r / min, 400 r / min, 450 r / min, 500 r / min) for 15-20 min (including but not limited to 15 min, 16 min, 17 min, 18 min, 19 min, 20 min) to ensure that all raw materials are mixed evenly and without clumping.

[0042] In some embodiments, in step 2, the uniformly mixed material is fed into a twin-screw extruder, and the feed section temperature is set to 380°C, the melt section temperature to 390°C, the extrusion section temperature to 400°C, and the screw speed to 200-250 r / min (including but not limited to 200 r / min, 210 r / min, 220 r / min, 230 r / min, 240 r / min, and 250 r / min).

[0043] In some implementations, vacuum drying in step 3 for 4-6 hours (including but not limited to 4 hours, 4.5 hours, 5 hours, 5.5 hours, and 6 hours) removes moisture from the particles and prevents bubbles and cracks from forming during subsequent molding processes.

[0044] A method for preparing a battery cell shell / encapsulation structure using PEEK-based composite modified material includes: preparing the battery cell shell / encapsulation structure by injection molding or compression molding process using the aforementioned PEEK-based composite modified material or PEEK-based composite modified particles, according to the external dimensions of the battery cell.

[0045] In some embodiments, the injection molding process is as follows: injection temperature 390-410℃ (including but not limited to 390℃, 395℃, 400℃, 405℃, 410℃), mold temperature 120-150℃ (including but not limited to 120℃, 130℃, 140℃, 150℃), injection pressure 50-80MPa (including but not limited to 50MPa, 60MPa, 70MPa, 80MPa), holding time 10-15s (including but not limited to 10s, 11s, 12s, 13s, 14s, 15s), after cooling and molding, the product is removed, trimmed and polished to remove burrs and flash, and the finished battery cell shell / encapsulation structure is obtained.

[0046] In some embodiments, the molding process is as follows: molding temperature 390-410℃ (including but not limited to 390℃, 395℃, 400℃, 405℃, 410℃), molding pressure 70-100MPa (including but not limited to 70MPa, 80MPa, 90MPa, 100MPa), holding time 15-50s (including but not limited to 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s), after cooling and molding, the product is removed, trimmed and polished to remove burrs and flash, and the finished cell shell / encapsulation structure is obtained.

[0047] This invention provides a method for preparing PEEK-based composite modified materials and a method for preparing battery cell shell / packaging structures. It optimizes the melt extrusion and injection / compression molding processes of PEEK-based composite modified materials, clarifies and quantifies process parameters, and ensures stable material performance. At the same time, it is compatible with existing power battery cell packaging production lines, eliminating the need for additional production equipment and enabling industrial-scale mass production. This solves the industry pain point of incompatibility between new materials and existing production processes.

[0048] An assembly component for a power battery cell includes a cell shell / encapsulation structure made of the aforementioned PEEK-based composite modified material. The cell shell / encapsulation structure is adapted to the external dimensions of square cells and pouch power cells. The overall shape of the cell shell / encapsulation structure is a cuboid box (suitable for square cells) or a thin encapsulation structure (suitable for pouch power cells). The length, width, and height dimensions are adjusted according to existing cell specifications (e.g., square cell shell: length 100-200mm, width 50-100mm, height 10-20mm).

[0049] In some embodiments, the thickness of the cell casing / packaging structure is 2-3mm (including but not limited to 2mm, 2.2mm, 2.5mm, 2.8mm, and 3mm).

[0050] In some embodiments, a sealing port is provided on the top of the cell housing / packaging structure for inserting and packaging the cell, and a sealing groove is provided on the edge of the sealing port to accommodate a sealing element.

[0051] In some embodiments, a high-temperature resistant silicone rubber sealing ring is embedded in the sealing groove of the encapsulation port to form a sealing structure. The sealing ring has a circular cross-section and a diameter of 3-5mm (including but not limited to 3mm, 3.5mm, 4mm, 4.5mm, and 5mm). It is precisely matched with the sealing groove and is fixed by a snap after encapsulation to ensure the sealing performance and prevent electrolyte leakage.

[0052] In some embodiments, the bottom and sides of the battery cell casing / packaging structure are provided with reinforcing ribs to improve structural strength. The spacing between the reinforcing ribs is 30-50mm (including but not limited to 30mm, 35mm, 40mm, 45mm, 50mm), and the thickness of the reinforcing ribs is 1-1.5mm (including but not limited to 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm).

[0053] In some embodiments, the inner wall of the cell casing / packaging structure and the edge of the packaging port are coated with a high-temperature resistant insulating coating with a thickness of 0.4-0.6 mm (including but not limited to 0.4 mm, 0.5 mm, and 0.6 mm) to form an insulating protective structure. The high-temperature resistant insulating coating has good compatibility with the PEEK-based composite modified material of the cell casing / packaging structure, further improving the insulation performance of the cell casing / packaging structure and preventing leakage caused by contact between the cell casing / packaging structure and the cell tab.

[0054] In some embodiments, the inner wall of the cell casing / encapsulation structure is provided with a high-temperature resistant silicone buffer layer with a thickness of 1-2mm (including but not limited to 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm). The high-temperature resistant silicone buffer layer is fixed to the cell casing / encapsulation structure by adhesive bonding to form an integrated buffer and heat insulation structure. This structure can absorb the expansion force generated during the charging and discharging of the cell and also play an auxiliary heat insulation role, preventing local overheating of the cell from being transferred to the casing.

[0055] In some embodiments, a positioning protrusion is provided at the bottom of the cell housing / encapsulation structure to form an assembly positioning structure that matches the positioning groove at the bottom of the cell. A buckle is provided on the side of the cell housing / encapsulation structure to form an assembly positioning structure for fixing the cell housing / encapsulation structure to the cell, ensuring convenient and reliable assembly and avoiding loosening during assembly.

[0056] The present invention provides an assembly component for power battery cells, which is suitable for integrated cell shell / encapsulation structures of square and soft-pack cells. It integrates four major functions: buffering and heat insulation, sealing, insulation, and positioning. It eliminates the need for additional insulation and heat insulation layers in traditional shells, simplifies the structural design, and improves protection reliability. It solves the defects of existing structures, such as complex assembly and limited protection performance.

[0057] The assembly method of the above-mentioned power battery cell assembly components is used to assemble the power battery cell externally. The assembly method includes: inserting the cell into the encapsulation port of the cell shell / encapsulation structure, positioning the cell through positioning protrusions and positioning grooves, and fixing the cell with buckles; embedding a sealing ring in the sealing groove, and completing the encapsulation using a hot-pressing encapsulation process to ensure sealing performance; after assembly, the cell shell / encapsulation structure is tightly fitted to the cell without looseness or gaps, and can be directly adapted to the existing power battery pack assembly process.

[0058] The assembly method of the power battery cell assembly assembly component of the present invention is compatible with the conventional packaging process of existing power battery cells and does not require additional production equipment.

[0059] In some embodiments, the hot-press packaging process conditions are as follows: hot-press temperature 150-180℃ (including but not limited to 150℃, 160℃, 170℃, 180℃, lower than the melting point of PEEK-based composite modified materials to avoid shell deformation), hot-press pressure 10-15MPa (including but not limited to 10MPa, 11MPa, 12MPa, 13MPa, 14MPa, 15MPa), and hot-press time 3-5min (including but not limited to 3min, 4min, 5min) to ensure that the sealing ring is tightly fitted to the cell shell / packaging structure and the cell to achieve a seal.

[0060] In some implementations, an airtightness test is performed after encapsulation. The test pressure is 0.1-0.2 MPa (including but not limited to 0.1 MPa, 0.15 MPa, and 0.2 MPa), and the pressure is maintained for 30 minutes. If there is no air or liquid leakage, it is considered qualified.

[0061] The performance testing standards and requirements are as follows: The PEEK-based composite modified cell shell / packaging structure and assembly components prepared by this invention must meet the following performance indicators and conform to the industry standard GB 38031 "Safety Requirements for Power Batteries for Electric Vehicles": High temperature resistance: Long-term operating temperature ≥250℃, short-term (30min) can withstand 300℃ high temperature, and after being placed at 250℃ for 24 hours, there is no deformation or cracking. Corrosion resistance: After immersion in a mixed electrolyte of dimethyl carbonate / ethylene carbonate for 72 hours, the surface showed no corrosion or discoloration, the dimensional change rate was ≤0.5%, and there was no cracking or leakage. Insulation performance: Insulation resistance ≥10 12 Ω, breakdown voltage ≥50kV / mm, no leakage current; Mechanical properties: Tensile strength ≥150MPa, impact strength ≥80kJ / m 2 The compressive strength is ≥5000N, which meets the impact and extrusion requirements during the assembly, transportation and use of power batteries; Lightweight performance: 30%-40% lighter than existing aluminum alloy shells of the same specifications, with density controlled at 1.4-1.5 g / cm³. 3 ; Sealing performance: No air or liquid leakage was found during the air tightness test (0.1-0.2MPa, 30min), meeting the sealing requirements for long-term use of power batteries.

[0062] Example 1 1. Raw material preparation: PEEK resin (model: Victrex 450G, melting point 334℃, tensile strength 98MPa, density 1.32g / cm³) 3 ): 82kg; Carbon fiber (T700, length 8μm): 10kg; Al2O3 ceramic particles (particle size 500nm): 5kg; Anti-aging agent 1010: 1kg; Maleic anhydride grafted PEEK compatibilizer: 2kg.

[0063] 2. Preparation of PEEK-based composite modified materials: Mixing: Place all the above raw materials into a high-speed mixer, set the temperature to 90℃ and the speed to 400r / min, mix for 18min to obtain a uniform mixture; Melt extrusion: The mixture is fed into a twin-screw extruder, with the feed section temperature set to 380℃, the melt section temperature to 390℃, the extrusion section temperature to 400℃, and the screw speed to 220r / min for extrusion granulation; Drying: Place the granulated particles into a vacuum drying oven, set the temperature to 130℃, and dry for 5 hours to remove moisture; 3. Battery cell casing molding process: The square battery cell casing is prepared by injection molding. The injection temperature is set to 400℃, the mold temperature to 130℃, the injection pressure to 60MPa, and the holding time to 12s. After cooling and molding, the edges are trimmed and polished to obtain the finished battery cell casing (dimensions: length 150mm, width 80mm, height 15mm, thickness 2.5mm).

[0064] 4. Assembly of components: A 0.5mm thick high-temperature resistant insulating coating is applied to the inner wall of the battery cell casing. After drying, a 1.5mm thick high-temperature resistant silicone buffer layer is fixed to the inner wall of the battery cell casing by adhesive bonding. A 4mm diameter high-temperature resistant silicone rubber sealing ring is embedded in the sealing groove of the battery cell casing. The square battery cell is inserted into the battery cell housing through the packaging port. The positioning protrusion on the bottom of the battery cell housing matches the positioning groove on the bottom of the battery cell, and the buckle is used to fix the battery cell. Thermo-press packaging process is adopted, with a set temperature of 160℃, a pressure of 12MPa, and a time of 4min to complete the packaging and obtain the assembled cell casing-cell assembly.

[0065] 5. Performance Testing and Results: According to the performance testing standards mentioned above, the prepared square battery cell casing and assembly components were tested, and the test data are as follows: High temperature resistance: After being placed at a constant temperature of 250℃ for 24 hours, the outer shell showed no deformation or cracking; after being placed at a constant temperature of 300℃ for 30 minutes, the outer shell showed no obvious deformation. Corrosion resistance: After immersion in a mixed electrolyte of dimethyl carbonate and ethylene carbonate for 72 hours, the outer shell surface showed no corrosion or discoloration, the dimensional change rate was 0.3%, and there was no leakage. Insulation performance: Insulation resistance 1.2×10⁻⁶ 12 Ω, breakdown voltage 55kV / mm, no leakage current; Mechanical properties: Tensile strength 160MPa, impact strength 85kJ / m 2 It has a compressive strength of 5500N, meeting the requirements for impact and extrusion protection; Lightweight performance: The casing weighs 0.28kg, which is 40% lighter than the aluminum alloy casing of the same specifications (0.47kg); Sealing performance: Under a pressure of 0.15MPa for 30 minutes, there is no leakage of air or liquid, and the sealing performance is qualified.

[0066] Test results show that the PEEK-based composite modified material square battery cell shell prepared in this embodiment fully meets the preset performance requirements, effectively solves the defects of the existing technology, and is suitable for the use of square power battery cells.

[0067] Example 2 The difference between this embodiment and Embodiment 1 is that the formulation and molding process of the PEEK-based composite modified material are slightly adjusted to adapt to soft-pack battery cells, as detailed below: 1. Raw material preparation: PEEK resin: 85kg; carbon fiber: 11kg; Al2O3 ceramic particles: 4kg; anti-aging agent 1010: 0.8kg; maleic anhydride grafted PEEK compatibilizer: 2.2kg; 3. Packaging structure molding process: The packaging structure of the soft-pack battery cell is prepared by molding process, with molding temperature of 395℃, molding pressure of 70MPa, holding time of 15s, and size adapted to soft-pack battery cell (length 200mm, width 100mm, height 5mm, thickness 2mm). 4. Assembly of components: The thin packaging structure is adapted to soft-pack cells, the reinforcing rib design is eliminated, and a sealing edge is added; the packaging process adopts thermo-press packaging, with a set temperature of 170℃, pressure of 14MPa, and time of 3min.

[0068] The specifications, preparation, and testing processes for the remaining raw materials are the same as in Example 1.

[0069] Testing showed that the packaging structure of the soft-pack battery cell prepared in this embodiment has a tensile strength of 155 MPa and an impact strength of 82 kJ / m. 2 Insulation resistance 1.1×10 12 Ω, with corrosion resistance and high temperature resistance meeting the preset requirements, and 14% lighter than PC / ABS plastic shells of the same specifications, it is suitable for the use of soft-pack power cells and can be mass-produced.

[0070] Comparative Example 1 Using existing aluminum alloy materials, a square battery cell casing of the same specifications as in Example 1 was prepared, resulting in an aluminum alloy casing.

[0071] The testing procedure was the same as in Example 1. The aluminum alloy casing of this comparative example weighed 0.47 kg, had a long-term operating temperature ≤180℃, and an insulation resistance of 10 Ω·cm. 8 Ω (requires additional insulation coating), slight corrosion occurs after immersion in electrolyte for 72 hours, tensile strength is 140MPa, and compressive strength is 5200N.

[0072] Comparative Example 2 Using existing PC / ABS plastic, a square battery cell casing of the same specifications as in Example 1 was prepared, resulting in a PC / ABS plastic casing.

[0073] The testing procedure was the same as in Example 1. The PC / ABS plastic casing of this comparative example weighed 0.32 kg, had a long-term operating temperature ≤150℃, and an insulation resistance of 10 Ω·cm. 9 Ω, slight cracking occurred after immersion in electrolyte for 72 hours, tensile strength 80MPa, compressive strength 3000N.

[0074] The comparison results between Examples 1-2 and Comparative Examples 1-2 show that the PEEK-based composite modified material cell shell / packaging structure prepared in Examples 1-2 of the present invention is significantly superior to the cell shell / packaging structure prepared with conventional materials in terms of core properties such as lightweight, high temperature resistance, insulation, corrosion resistance, and mechanical strength, highlighting the technical advantages and practicality of the present invention.

[0075] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A PEEK-based composite modified material for use in battery cell casing / packaging structures, characterized in that, The raw materials, by mass fraction, include: 80%-85% PEEK resin, 10%-12% carbon fiber, 3%-5% Al2O3 ceramic particles, 0.5%-1% anti-aging agent, and 1%-2% compatibilizer.

2. The PEEK-based composite modified material according to claim 1, characterized in that, It should include at least one of the following technical features: (1) The length of the carbon fiber is 5-10 μm; (2) The particle size of the Al2O3 ceramic particles is 100-500 nm; (3) The anti-aging agent includes at least one of hindered phenols, phosphites, and thioethers; (4) The compatibilizer is a maleic anhydride-grafted PEEK compatibilizer, and the grafting rate of the maleic anhydride-grafted PEEK compatibilizer is 0.2%-1.0%.

3. The method for preparing the PEEK-based composite modified material according to claim 1 or 2, characterized in that, Includes the following steps: Step 1, Mixing: Add PEEK resin, carbon fiber, Al2O3 ceramic particles, anti-aging agent, and compatibilizer in proportion, and mix evenly at a temperature of 80-100℃; Step 2, melt extrusion and granulation: Extrusion temperature 380-400℃, followed by granulation; Step 3, Drying: The granulated particles are vacuum dried at a temperature of 120-150℃ to obtain PEEK-based composite modified particles.

4. A method for preparing a PEEK-based composite modified material battery cell casing / packaging structure, comprising using the PEEK-based composite modified material as described in claim 1 or 2, or the PEEK-based composite modified material prepared by the method described in claim 3, characterized in that... The cell casing / packaging structure is prepared by injection molding or compression molding processes; The injection molding process is as follows: injection temperature 390-410℃, mold temperature 120-150℃, injection pressure 50-80MPa, holding time 10-15s, and then removed after cooling and molding. The molding process is as follows: molding temperature 390-410℃, molding pressure 70-100MPa, holding time 15-50s, and then removed after cooling and molding.

5. An assembly component for a power battery cell, characterized in that, The cell casing / packaging structure includes a PEEK-based composite modified material prepared by the preparation method described in claim 4.

6. The assembly assembly for the power battery cell according to claim 5, characterized in that, It should include at least one of the following technical features: (1) The battery cell casing / packaging structure is generally a rectangular box or a thin packaging structure; (2) The thickness of the cell casing / packaging structure is 2-3 mm; (3) A packaging port is provided on the top of the cell casing / packaging structure; (4) The inner wall of the cell casing / encapsulation structure and the edge of the encapsulation opening are coated with an insulating coating with a thickness of 0.4-0.6 mm; (5) A buffer layer with a thickness of 1-2 mm is provided on the inner wall of the cell casing / packaging structure; (6) The bottom of the cell housing / packaging structure is provided with a positioning protrusion, and the side of the cell housing / packaging structure is provided with a buckle.

7. The assembly assembly for the power battery cell according to claim 6, characterized in that, It should include at least one of the following technical features: (1) A sealing groove is provided at the edge of the encapsulation port, and a sealing ring is embedded in the sealing groove; (2) The bottom and sides of the battery cell casing / packaging structure are provided with reinforcing ribs.

8. The assembly assembly for the power battery cell according to claim 7, characterized in that, It should include at least one of the following technical features: (1) The diameter of the sealing ring section is 3-5 mm; (2) The spacing of the reinforcing ribs is 30-50mm, and the thickness of the reinforcing ribs is 1-1.5mm.

9. The assembly method of the power battery cell assembly assembly as described in any one of claims 5 to 8, wherein the assembly is external to the power battery cell, characterized in that, The assembly method includes: inserting the battery cell into the packaging port of the battery cell shell / packaging structure, fixing the battery cell after positioning; embedding a sealing ring in the sealing groove, and completing the packaging using a thermo-pressing packaging process.

10. The assembly method of the power battery cell assembly assembly according to claim 9, characterized in that, The hot-pressing encapsulation process conditions are: hot-pressing temperature 150-180℃, hot-pressing pressure 10-15MPa, and hot-pressing time 3-5min.