Antistatic polyketone composite material as well as preparation method and application thereof

Abstract

The invention provides an antistatic polyketone composite material as well as a preparation method and application thereof. The antistatic polyketone composite material comprises the following components in percentage by mass: 70-90% of polyketone resin; 0.5%-5% of a hydroxylated quaternary ammonium salt antistatic agent; 1%-3% of a surface hydroxyl modified carbon nanotube; 0.5% to 1.5% of graphene nanoplatelets; 3%-6% of fluorinated polyether ketone; 1%-5% of a phosphazene flame retardant; and 0.01%-0.2% of a conductivity regulator. The antistatic polyketone composite material provided by the invention has permanent and stable antistatic property, and has excellent electrolyte resistance, high flame retardance and good ionic conductivity on the basis of keeping high mechanical strength and high heat resistance of polyketone, and a battery test shows that the antistatic polyketone composite material has a good application prospect. And the cycle life (500-time capacity retention ratio is greater than or equal to 92%) and the thermal safety are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials technology, and particularly relates to an antistatic polyketone composite material, its preparation method and application. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage power stations, the energy density and safety requirements of new energy batteries such as lithium-ion batteries are increasing. During the production and operation of batteries, static electricity is easily generated and accumulated due to friction, separation, and other factors. Static electricity accumulation can cause a series of serious problems: inside the battery, high static voltage may cause electrochemical decomposition of the electrolyte or break through the micropores of the separator, causing internal short circuits and triggering thermal runaway; outside the battery, static electricity attracts dust, affecting the cleanliness of the battery pack and even interfering with the normal operation of precision electronic components such as the BMS.

[0003] Currently, the common approach to solving static electricity problems is to add small-molecule antistatic agents or conductive fillers (such as carbon black). However, small-molecule antistatic agents are prone to migration and precipitation, their effects are not lasting, and they may contaminate the electrolyte; high amounts of fillers such as carbon black can severely damage the mechanical properties and processing flowability of the matrix material. In addition, existing antistatic materials (such as antistatic PP and PBT) often have shortcomings in terms of electrolyte corrosion resistance, high temperature resistance, and flame retardancy, making it difficult to meet the application requirements of high-safety-standard batteries.

[0004] Polyketone resin is a high-performance engineering plastic polymerized by alternating polymerization of olefins and carbon monoxide. It possesses high crystallinity, high strength, high toughness, excellent chemical resistance, and intrinsic flame retardancy, making it an ideal matrix for battery materials. However, pure polyketone has extremely high volume resistivity (>10). 14 (Ω·cm) is a typical insulator. How to impart stable and durable antistatic properties to it without sacrificing its inherent advantages, and make it suitable for the harsh environments of batteries, is a pressing technical challenge in this field. Summary of the Invention

[0005] The purpose of this invention is to provide an antistatic polyketone composite material, its preparation method and application. The antistatic polyketone composite material of this invention has excellent permanent antistatic properties, high mechanical strength, resistance to electrolyte corrosion and flame retardancy.

[0006] This invention provides an antistatic polyketone composite material comprising the following components by mass fraction:

[0007] Polyketone resin: 70%~90%;

[0008] Hydroxylated quaternary ammonium salt antistatic agents: 0.5%~5%;

[0009] Surface-hydroxyl-modified carbon nanotubes: 1%~3%;

[0010] Graphene microsheets: 0.5%~1.5%;

[0011] Fluorinated polyetherketone: 3%~6%;

[0012] Phosphazene flame retardant: 1%~5%;

[0013] Conductivity modifier: 0.01%~0.2%.

[0014] Preferably, the molecular weight of the polyketone resin is 1000~200000;

[0015] The polyketone is a terpolymer of carbon monoxide, ethylene, and propylene, with an propylene insertion rate of 4-8%.

[0016] Preferably, the hydroxylated quaternary ammonium salt antistatic agent is a quaternary ammonium salt containing an alkyl chain of C12 to C22 and a hydroxyalkyl group.

[0017] Preferably, the hydroxylated quaternary ammonium salt antistatic agent includes one or more of tetradecylmethyldiethylhydroxyammonium bromide, hexadecylmethyldiethylhydroxyammonium bromide, docosylhydroxypropyl quaternary ammonium salt, dimethylhydroxyethylstearamide ethyl quaternary ammonium nitrate, and hexadecylhydroxyethyldimethylammonium chloride.

[0018] Preferably, the phosphazene flame retardant includes one or more of cyclic phosphazene compounds, linear phosphazene compounds, phosphazene salt compounds, silicon-modified phosphazene compounds, and waterborne phosphazene compounds.

[0019] This invention provides a method for preparing the antistatic polyketone composite material as described above, comprising the following steps:

[0020] The antistatic polyketone composite material is obtained by melt blending polyketone resin, hydroxylated quaternary ammonium salt antistatic agent, surface hydroxyl-modified carbon nanotubes, graphene microsheets, fluorinated polyether ketone, phosphazene flame retardant and conductivity modifier, and then extruding and granulating.

[0021] Preferably, the melt blending temperature is 210~260℃, and ultrasonic dispersion is performed simultaneously during the melt blending process, with the ultrasonic power being 300~500W.

[0022] This invention provides a new energy battery component, including the antistatic polyketone composite material described above.

[0023] Preferably, the new energy battery components include one or more of the following: a separator, a battery module bracket, a tab protective sleeve, and an electrolyte delivery pipeline.

[0024] This invention provides a new energy battery, including the new energy battery components described above.

[0025] This invention provides an antistatic polyketone composite material comprising the following components by mass fraction: polyketone resin: 70%~90%; hydroxylated quaternary ammonium salt antistatic agent: 0.5%~5%; surface hydroxyl-modified carbon nanotubes: 1%~3%; graphene microsheets: 0.5%~1.5%; fluorinated polyetherketone: 3%~6%; phosphazene flame retardant: 1%~5%; and conductivity modifier: 0.01%~0.2%.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. Permanent and stable antistatic properties: Addressing the high polarity and high crystallinity of polyketone resins, and the highly polar and oxidizing electrolyte environment in new energy batteries, a synergistic combination of hydroxylated quaternary ammonium salt antistatic agents, surface-hydroxyl-modified carbon nanotubes, and graphene microsheets was specifically selected to construct a stable and environmentally resistant "ion-electron" dual-pathway conductive network, with a surface resistivity consistently maintained at 10 Ω·cm. 6 ~10 9 Ω solves the problem of migration failure of small molecule antistatic agents.

[0028] 2. Excellent comprehensive performance: While maintaining the high mechanical strength (tensile strength ≥85MPa) and high heat resistance (heat distortion temperature ≥180℃) of polyketone, the material also possesses excellent electrolyte resistance (volume change rate ≤2%), high flame retardancy (UL94 V-0), and good ionic conductivity (≥1.0×10⁻⁶). -3 S / cm).

[0029] 3. Significantly Improved Battery Safety and Lifespan: Separators and structural components made with this material effectively eliminate electrostatic hazards and prevent electrolyte decomposition and separator breakdown. Battery testing shows that both cycle life (capacity retention ≥92% after 500 cycles) and thermal safety are significantly improved. Detailed Implementation

[0030] This invention provides an antistatic polyketone composite material comprising the following components by mass fraction:

[0031] Polyketone resin: 70%~90%;

[0032] Hydroxylated quaternary ammonium salt antistatic agents: 0.5%~5%;

[0033] Surface-hydroxyl-modified carbon nanotubes: 1%~3%;

[0034] Graphene microsheets: 0.5%~1.5%;

[0035] Fluorinated polyetherketone: 3%~6%;

[0036] Phosphazene flame retardant: 1%~5%;

[0037] Conductivity modifier: 0.01%~0.2%.

[0038] In this invention, the polyketone resin is preferably a terpolymer of carbon monoxide, ethylene, and propylene. In the polyketone resin, the molar fraction of the propylene segment is preferably 4-9%, more preferably 5-7%. The melt flow rate (melt index) of the polyketone resin at 240°C and 2.16 kg load is preferably 3-80 g / 10 min, more preferably 5-50 g / 10 min. The number-average molecular weight determined by gel permeation chromatography is preferably 1000-200000, more preferably 30000-100000. The molecular weight distribution is preferably 1.5-3, more preferably 1.8-2.5.

[0039] In this invention, the mass fraction of the polyketone resin is preferably 70-90%, more preferably 75-85%, such as 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, preferably a range of values ​​with the above values ​​as the upper or lower limit.

[0040] In this invention, polyketone resin, as a highly crystalline and highly polar engineering plastic, has a regular molecular chain arrangement and high surface energy, resulting in poor interfacial compatibility with conventional antistatic agents or conductive fillers. This makes it difficult to stably construct existing composite conductive networks in polyketone. Furthermore, carbonate electrolytes in new energy batteries exhibit strong polarity and solubility, easily extracting or destroying conventional antistatic structures. Based on this, this invention designs an antistatic system synergistically compounded from hydroxylated quaternary ammonium salt antistatic agents, surface-hydroxyl-modified carbon nanotubes, and graphene microsheets.

[0041] In this invention, the hydroxylated quaternary ammonium salt antistatic agent is preferably a quaternary ammonium salt containing a C12-C22 alkyl chain and a hydroxyalkyl group, more preferably one or more of tetradecylmethyldiethylhydroxyammonium bromide, hexadecylmethyldiethylhydroxyammonium bromide, docosylhydroxypropyl quaternary ammonium salt, dimethylhydroxyethylstearamide ethyl quaternary ammonium nitrate, and hexadecylhydroxyethyldimethylammonium chloride; the hydroxyl groups (-OH) in the hydroxylated quaternary ammonium salt antistatic agent molecule can form hydrogen bonds with the carbonyl groups in the polyketide chain segment, enhancing interfacial bonding and preventing migration during processing or use; the quaternary ammonium salt cation has a high degree of dissociation in the polyketide matrix, which is beneficial for forming a stable ionic conductive channel; compared with other ionic antistatic agents (such as sulfonates and phosphate esters), hydroxylated quaternary ammonium salts have lower solubility in electrolytes and stronger anti-extraction ability.

[0042] In this invention, the mass fraction of the hydroxylated quaternary ammonium salt antistatic agent is preferably 0.5-5%, more preferably 1-4%, such as 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, preferably a range of values ​​with the above values ​​as the upper or lower limit.

[0043] In this invention, the hydroxyl content in the surface-modified carbon nanotubes is preferably 0.5~5.0 wt%. The hydroxyl content is a key parameter affecting its interaction with quaternary ammonium salts and the polyketide matrix. If the hydroxyl content is too low (<0.5 wt%), it is difficult to form a sufficient number of hydrogen bonds with the hydroxylated quaternary ammonium salt, limiting its enhancement effect on the connectivity and stability of the "ion-electron" conductive network; if the hydroxyl content is too high (>5.0 wt%), it may excessively disrupt the conjugated structure of the carbon nanotubes, leading to a decrease in their intrinsic conductivity and thus impairing the construction of the electronic conductive network. The preferred hydroxyl content is 0.71~2.92 wt%, within which good interfacial interactions are ensured while maintaining the excellent conductivity of the carbon nanotubes. Preferably, the hydroxyl content in the surface-hydroxyl-modified carbon nanotubes is 1~4 wt%, such as 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, preferably a range of values ​​with any of the above values ​​as the upper or lower limit.

[0044] Furthermore, the size parameters of the surface-hydroxyl-modified carbon nanotubes also significantly influence their performance. Preferably, the carbon nanotubes have a diameter of 3–15 nm, a length of 5–30 μm, and an aspect ratio greater than 500. The size parameters of the carbon nanotubes directly affect their dispersion state and the efficiency of conductive network construction in the polyketide matrix. If the diameter of the carbon nanotubes is too large (>20 nm), their specific surface area decreases, weakening the interfacial interaction with quaternary ammonium salts and graphene; if the length is too short (<1 μm), it is difficult to form an effective overlapping structure with graphene microsheets; if the length is too long (>50 μm) or the aspect ratio is too high, entanglement and aggregation are likely to occur, affecting the dispersion uniformity and thus impairing the mechanical properties of the composite material and the stability of the conductive network. The diameter of the surface-hydroxyl-modified carbon nanotubes is preferably 3–15 nm, more preferably 5–12 nm, such as 3 nm, 5 nm, 8 nm, 10 nm, 12 nm, 15 nm, etc. nm, preferably a range of values ​​with any of the above values ​​as the upper or lower limit; the length of the surface hydroxyl modification is preferably 5~30μm, more preferably 10~25μm, such as 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, preferably a range of values ​​with any of the above values ​​as the upper or lower limit; the aspect ratio is preferably 500~10000, more preferably 500~5000, such as 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, preferably a range of values ​​with any of the above values ​​as the upper or lower limit.

[0045] Specifically, surface-hydroxyl-modified carbon nanotubes not only improve their dispersibility in the polyketide matrix, but also form hydrogen bonds with hydroxylated quaternary ammonium salts, enhancing the connectivity and stability of the "ion-electron" conductive network. Compared to ordinary carbon nanotubes or graphene, surface-hydroxyl-modified fillers are more likely to form a three-dimensional conductive network in highly polar polyketide systems and are less prone to failure due to electrolyte wetting. In some embodiments of the present invention, the surface-hydroxyl-modified carbon nanotubes are preferably MWCNT-OH (Pioneer Nano), NC7000-OH (Belgium Nanocyl SA), or CNT-OH (Pioneer Nano).

[0046] In this invention, the mass fraction of the surface hydroxyl-modified carbon nanotubes is preferably 1 to 3%, more preferably 1.5 to 2.5%, such as 1%, 1.5%, 2%, 2.5%, 3%, and preferably a range of values ​​above or below.

[0047] In this invention, the graphene microsheets are preferably 5-50 nm thick and 1-20 μm in diameter. The size of the graphene microsheets has a significant impact on their dispersion, overlapping efficiency, and the shielding network they form in the matrix. If the size is too small (thickness < 5 nm and diameter < 1 μm), it is difficult to effectively bridge carbon nanotubes, reducing the efficiency of constructing a three-dimensional conductive network. If the size is too large (thickness > 50 nm or diameter > 20 μm), they are prone to agglomeration in the matrix, leading to uneven dispersion. This not only affects the uniformity of the conductive network but may also become stress concentration points, damaging the mechanical properties of the material. More preferably, the graphene microsheets are 5-15 nm thick and 5-10 μm in diameter. Microsheets in this size range have the best aspect ratio and dispersion, enabling them to form a highly efficient "point-line-surface" three-dimensional conductive network with carbon nanotubes. The mass fraction of the graphene microsheets is preferably 0.5-1.5%, more preferably 0.8-1.2%, such as 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, and preferably a range of values ​​with the above values ​​as the upper or lower limit.

[0048] Meanwhile, the large specific surface area and excellent barrier properties of graphene microsheets can physically block the penetration and extraction of electrolyte small molecules into the quaternary ammonium salt ion-conducting channels, thus, together with hydroxylated carbon nanotubes, forming a spatial "anchoring" and protective effect on the ion-conducting network. The synergy of these three elements ultimately forms an "ion-electron" dual-network structure, where quaternary ammonium salt provides ion conduction, and carbon nanotubes and graphene microsheets jointly construct an efficient and stable electronic conduction pathway, achieving an enhanced antistatic effect greater than the sum of its parts (1+1+1>3).

[0049] In this invention, the mass fraction of the fluorinated polyether ketone is preferably 3-6%, more preferably 4-5%, such as 3%, 3.5%, 4%, 4.5%, 5%, and preferably a range of values ​​with the above values ​​as the upper or lower limit.

[0050] In this invention, the phosphazene flame retardant is preferably one or more of cyclic phosphazene compounds, linear phosphazene compounds, phosphazene salt compounds, silicon-modified phosphazene compounds, and waterborne phosphazene compounds. Specifically, in some embodiments of this invention, it may be one or more of HPCTP (hexaphenoxycyclotriphosphazene), ethoxy(pentafluoro)cyclotriphosphazene, and Silquest® PN-1000 (Momentive). The mass fraction of the phosphazene flame retardant is preferably 1~5%, more preferably 2~4%, such as 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, preferably within the range of the above values ​​as the upper or lower limit.

[0051] In this invention, the conductivity modifier is preferably one or more of polyethylene glycol (PEG, molecular weight 2000~10000), polyethylene oxide (PEO), ion exchange resin (such as sulfonic acid type cation exchange resin), and conductive carbon black (which needs to be combined with a dispersant such as zinc stearate to avoid filler agglomeration); the mass fraction of the conductivity modifier is preferably 0.01~0.2%, more preferably 0.05~0.15%, such as 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, preferably within a range where any of the above values ​​are the upper or lower limit.

[0052] This invention provides a method for preparing the antistatic polyketone composite material as described above, comprising the following steps:

[0053] The antistatic polyketone composite material is obtained by melt blending polyketone resin, hydroxylated quaternary ammonium salt antistatic agent, surface hydroxyl-modified carbon nanotubes, graphene microsheets, fluorinated polyether ketone, phosphazene flame retardant and conductivity modifier, and then extruding and granulating.

[0054] In this invention, the types and amounts of the polyketone resin, hydroxylated quaternary ammonium salt antistatic agent, surface hydroxyl-modified carbon nanotubes, graphene microsheets, fluorinated polyetherketone, phosphazene flame retardant, and conductivity modifier are the same as those described above, and will not be repeated here.

[0055] In this invention, the above-mentioned components are preferably placed in a twin-screw extruder for melt blending, followed by high-frequency ultrasonic dispersion, and then extruded and granulated to obtain antistatic polyketone composite material masterbatch. This invention, through a combination of melt blending and high-frequency ultrasonic dispersion, ensures that nanoscale conductive fillers are uniformly dispersed in the polyketone matrix, avoiding agglomeration and thus achieving high-performance materials.

[0056] In this invention, the melt blending temperature is preferably 210~260℃, more preferably 220~250℃, such as 210℃, 215℃, 220℃, 225℃, 230℃, 235℃, 240℃, 245℃, 250℃, 255℃, 260℃, and preferably a range of any of the above values ​​as the upper or lower limit; when the number average molecular weight of the polyketone resin is below 60,000, the melt blending temperature is preferably 210~220℃. The temperature is preferably 3℃, more preferably 215~220℃; the power of the ultrasonic dispersion is preferably 300~500W, more preferably 350~450W; the screw speed of the twin-screw extruder is preferably 250~350r / min, more preferably 300~320r / min; the length-to-diameter ratio of the twin screw is preferably 20~40, more preferably 25~35; the speed of the main feed screw is preferably 18~25r / min, more preferably 20~25r / min.

[0057] The present invention also provides a new energy battery component, which may be one or more of a battery separator, a battery module bracket, a tab protective sleeve, and an electrolyte delivery pipeline; the new energy battery component includes the antistatic polyketone composite material described above, or is prepared from the antistatic polyketone composite material described above.

[0058] In this invention, the battery separator includes a base film, a functional layer composited on the surface of the base film, and a protective layer coated on the surface of the functional layer. The functional layer is prepared by electrospinning and in-situ modification of the antistatic polyketone composite material described above. This functional layer is not only antistatic but also has good ionic conductivity and puncture resistance. Specifically, in some embodiments of this invention, the battery separator is preferably prepared according to the following steps:

[0059] A) Preparation of spinning solution: Dissolve the obtained antistatic polyketone masterbatch in a mixed solvent composed of hexafluoroisopropanol and methanol, and stir to form a homogeneous spinning solution;

[0060] B) Electrospinning: Spinning solution onto the surface of a porous base membrane to form a polyketone nanofiber coating;

[0061] C) In-situ modification: The spun diaphragm is immersed in an aqueous solution of sodium borohydride for modification, followed by washing and drying;

[0062] D) Hot pressing: The coating is hot pressed;

[0063] E) Protective layer coating: An epoxy resin-modified polyketone solution is coated on the surface of the functional layer, and after curing, a three-layer composite membrane is obtained.

[0064] In this invention, the mass fraction of antistatic polyketone masterbatch in the raw materials for preparing the spinning solution is preferably 7-10%, more preferably 8-9%; the mass fraction of hexafluoroisopropanol is preferably 75-90%, more preferably 80-85%, and even more preferably 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, or 90%, preferably within the range of any of the above values ​​as the upper or lower limit; the mass fraction of methanol is preferably 6-10%, more preferably 7-9%, such as 6%, 7%, 8%, 9%, or 10%, preferably within the range of any of the above values ​​as the upper or lower limit.

[0065] In this invention, the voltage of the electrospinning is preferably 8~12kV, more preferably 9~10kV, the injection flow rate of the electrospinning is preferably 0.7~0.9mL / h, more preferably 0.7~0.8 mL / h, and the ambient humidity is preferably 40~60%, more preferably 45~55%.

[0066] In this invention, the mass concentration of the sodium borohydride aqueous solution is preferably 0.3~1.0wt%, more preferably 0.5~0.6wt%; the in-situ modification temperature is preferably 20~30℃, more preferably 20~25℃; and the in-situ modification time is preferably 5~10min.

[0067] In this invention, the hot pressing temperature is preferably 20~50℃, more preferably 30~40℃, such as 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, preferably a range of values ​​with any of the above values ​​as the upper or lower limit; the hot pressing pressure is preferably 40~60MPa, more preferably 45~55MPa, such as 40 MPa, 45 MPa, 50 MPa, 55 MPa, 60MPa, preferably a range of values ​​with any of the above values ​​as the upper or lower limit.

[0068] In this invention, the epoxy resin-modified polyketone solution can be prepared by itself. 10 parts by weight of bisphenol A type epoxy resin (such as E-44, epoxy equivalent 210~230 g / eq) and 90 parts by weight of polyketone resin are melt-blended at 280°C for 30 minutes. After extrusion granulation, the solution is dissolved in hexafluoroisopropanol to prepare a 5~10 wt% solution. The curing process after the protective layer is coated preferably includes pre-curing and post-curing in sequence. The pre-curing temperature is preferably 80~120℃, more preferably 90~110℃, such as 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, preferably within the range of any of the above values ​​as the upper or lower limit. The pre-curing time is preferably 30~60 min, more preferably 40~50 min. The post-curing temperature is preferably 150~200℃, more preferably 160~180℃, such as 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, preferably within the range of any of the above values ​​as the upper or lower limit. The post-curing time is preferably 2~4 hours, more preferably 2.5~3 hours. Through the sequential pre-curing and post-curing, the epoxy groups are fully cross-linked, forming a dense protective layer.

[0069] In this invention, the battery module bracket, electrode protective sleeve, and electrolyte delivery pipeline, and other battery structural components are preferably made of the antistatic polyketone composite material described above through injection molding, and are designed with static discharge channels to achieve rapid static discharge. The surface resistance of the static discharge channels is ≤10 Ω. 8 Ω.

[0070] This invention provides an antistatic polyketone composite material comprising the following components by mass fraction: polyketone resin: 70%~90%; hydroxylated quaternary ammonium salt antistatic agent: 0.5%~5%; surface hydroxyl-modified carbon nanotubes: 1%~3%; graphene microsheets: 0.5%~1.5%; fluorinated polyetherketone: 3%~6%; phosphazene flame retardant: 1%~5%; and conductivity modifier: 0.01%~0.2%.

[0071] The beneficial effects of this invention are as follows:

[0072] 1. Permanent and stable antistatic properties: Addressing the high polarity and high crystallinity of polyketone resins, and the highly polar and oxidizing electrolyte environment in new energy batteries, a synergistic combination of hydroxylated quaternary ammonium salt antistatic agents, surface-hydroxyl-modified carbon nanotubes, and graphene microsheets was specifically selected to construct a stable and environmentally resistant "ion-electron" dual-pathway conductive network, with a surface resistivity consistently maintained at 10 Ω·cm. 6 ~10 9 Ω solves the problem of migration failure of small molecule antistatic agents.

[0073] 2. Excellent comprehensive performance: While maintaining the high mechanical strength (tensile strength ≥85MPa) and high heat resistance (heat distortion temperature ≥180℃) of polyketone, the material also possesses excellent electrolyte resistance (volume change rate ≤2%), high flame retardancy (UL94 V-0), and good ionic conductivity (≥1.0×10⁻⁶). -3 S / cm).

[0074] 3. Significantly Improved Battery Safety and Lifespan: Separators and structural components made with this material effectively eliminate electrostatic hazards and prevent electrolyte decomposition and separator breakdown. Battery testing shows that both cycle life (capacity retention ≥92% after 500 cycles) and thermal safety are significantly improved.

[0075] To further illustrate the present invention, the following detailed description of an antistatic polyketone composite material, its preparation method, and its application, in conjunction with embodiments, is provided by the present invention, but should not be construed as limiting the scope of protection of the present invention.

[0076] The polyketone raw material used in the following embodiments of the present invention is a self-made product of our company (which can be obtained according to patent CN 110684189B). The other raw materials are commercially available products, specifically including:

[0077] A: Polyketone resin products;

[0078] B: Hydroxylated quaternary ammonium salt antistatic agents;

[0079] C: Carbon nanotubes with surface hydroxyl-modified surfaces;

[0080] D: Graphene microplates;

[0081] E: Fluorinated polyetherketone;

[0082] F: Phosphazene flame retardant;

[0083] G: Conductivity modifier;

[0084] The composition of the examples, comparative examples, and control groups is shown in Table 1, by mass percentage.

[0085] Table 1. Raw material composition of Examples 1-5, Comparative Examples 1-3, and the control group.

[0086]

[0087] Example 1

[0088] The specific methods for preparing antistatic polyketone masterbatch and membrane coating are as follows:

[0089] (1) Masterbatch preparation: Weigh the above materials according to the weight percentages in Table 1 and mix them in a high-speed mixer for 5 minutes. The antistatic agent is tetradecylmethyldiethylhydroxyammonium bromide, the surface hydroxyl-modified carbon nanotubes are MWCNT-OH (Xianfeng Nano, hydroxyl content 0.71 wt%, diameter 8~15 nm, length 10~30 μm), and the graphene microsheets are 5~15 nm thick and 5~10 μm in diameter. Then, feed them into a co-rotating twin-screw extruder. Set the temperatures of each section of the extruder as follows: feed section 235℃, melt section 250℃, die head 245℃, and screw speed 300 r / min. Turn on the ultrasonic-assisted dispersion device with a power of 400W in the melt section. After melt extrusion, cool with water and pelletize to obtain antistatic polyketide masterbatch.

[0090] (2) Preparation of spinning solution and electrospinning: Take 8 parts by weight of the above masterbatch and dissolve it in a mixed solvent of 85 parts by weight of hexafluoroisopropanol and 7 parts by weight of methanol. Stir magnetically for 3 hours until completely dissolved to obtain a uniform and transparent spinning solution. Inject the spinning solution into an injection pump equipped with a 27-gauge needle. Using a polyethylene porous base membrane as the receiving substrate, set the spinning voltage to 10KV, the injection flow rate to 0.8 ml / h, the ambient humidity to 50%, and the spinning time to 3.5 hours to form a polyketone nanofiber coating of about 10μm thickness on the base membrane.

[0091] (3) In-situ modification and post-treatment: The coated diaphragm was immersed in a 0.5 wt% sodium borohydride aqueous solution for 8 minutes. After removal, it was washed twice each with deionized water, acetone, and n-hexane. Then it was dried in a vacuum oven at 38°C for 24 hours.

[0092] (4) Hot pressing and protective coating: The dried diaphragm is hot-pressed at 35°C and 50MPa. Then, a layer of epoxy resin-modified polyketide solution is coated on the surface of the nanofiber layer. After curing, a cross-linked protective layer with a thickness of about 2.5μm is formed, and finally a three-layer composite antistatic diaphragm is obtained.

[0093] Example 2

[0094] Weigh the materials according to the proportions in Table 1, and prepare them using the same method as in Example 1.

[0095] Example 3

[0096] Weigh the materials according to the proportions in Table 1. Replace the antistatic agent with hexadecylmethyldiethylhydroxyammonium bromide and prepare it using the same method as in Example 1.

[0097] Example 4

[0098] Weigh the materials according to the proportions in Table 1. Replace the antistatic agent with docosylhydroxypropyl quaternary ammonium salt and prepare it using the same method as in Example 1.

[0099] Comparative Example 1

[0100] Weigh the materials according to the proportions in Table 1, and follow the same procedure as in Example 3.

[0101] Comparative Example 2

[0102] Weigh the materials according to the proportions in Table 1, and follow the same procedure as in Example 3.

[0103] Comparative Example 3

[0104] Weigh the materials according to the proportions in Table 1, and follow the same procedure as in Example 3.

[0105] Comparative Example 4

[0106] Weigh the materials according to the proportions in Table 1, and follow the same procedure as in Example 3.

[0107] Comparative Example 5

[0108] The “hydroxylated quaternary ammonium salt” in Example 3 was replaced with an equal amount of sodium dodecyl sulfonate, while the remaining components and process remained unchanged.

[0109] Comparative Example 6

[0110] Replace the “surface hydroxyl-modified carbon nanotubes” in Example 3 with an equal amount of unmodified multi-walled carbon nanotubes, while keeping the other components and processes unchanged.

[0111] Comparative Example 7

[0112] The “graphene microplates” in Example 1 were replaced with an equal amount of ordinary graphite powder, while the other components and processes remained unchanged.

[0113] Comparative Example 8

[0114] The "hydroxylated quaternary ammonium salt antistatic agent + surface hydroxyl-modified carbon nanotubes + graphene microplates" in Example 3 were replaced in equal amounts with a mixture of bis(octadecyl dimethyl ammonium chloride) (DODMAC), polyethylene glycol stearate (PEG-400S), and PEDOT:PSS in a ratio of 1:0.8:0.2. The remaining components and processes were the same as in Example 3.

[0115] Comparative Example 9

[0116] The “hydroxylated quaternary ammonium salt” in Example 3 was replaced with dioctadecyl dimethyl ammonium chloride (DODMAC), while the other components and processes remained unchanged.

[0117] Comparative Example 10

[0118] Traditional carbon black-filled polypropylene (PP) was used as a comparison. The PP resin accounted for 85% and the conductive carbon black accounted for 15%. After being granulated by twin-screw extrusion, it was injection molded into standard test strips.

[0119] Comparative Example 11

[0120] We used a commercially available ceramic-coated polyolefin separator (Enjie) as a comparison.

[0121] Performance Testing and Result Analysis

[0122] The materials and products obtained in Examples 1-4 and Comparative Examples 1-11 were subjected to performance tests, and the results are shown in Tables 1-2.

[0123] Electrolyte immersion volume change rate test procedure: A standard injection-molded sample (50mm × 10mm × 4mm) was vacuum-dried at 60℃ for 24 hours. After weighing and measuring its dimensions, it was completely immersed in a 1M LiPF6 EC / DMC / EMC (volume ratio 1:1:1) electrolyte and sealed at 60℃ for 720 hours. After removal, the surface was quickly rinsed with anhydrous ethanol, vacuum-dried for 24 hours, and weighed and measured again. Volume change rate = |(Volume after immersion - Volume before immersion)| / Volume before immersion × 100%.

[0124] Table 1 Performance tests of the masterbatches obtained in Examples 1-4 and Comparative Examples 1-10

[0125]

[0126] Table 2 Battery performance tests of the separators obtained in Examples 1-4 and Comparative Example 11

[0127]

[0128] The above comparison results show that only by using the specific combination of "hydroxylated quaternary ammonium salt + surface hydroxyl-modified carbon nanotubes + graphene microsheets" can a stable and electrolyte-resistant "ion-electron" dual conductive network be constructed in the polyketide matrix, which cannot be replaced by other similar substances.

[0129] In summary, based on the molecular structure characteristics of polyketone resin and the special requirements of the electrolyte environment of new energy batteries, this invention achieves synergistic effects among antistatic agents and conductive fillers with specific functional groups (such as hydroxyl groups) by screening them. This results in the endowment of polyketone with durable, stable, and electrolyte-resistant antistatic properties while maintaining its excellent mechanical properties and chemical resistance.

[0130] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An antistatic polyketone composite material, comprising the following components by mass fraction: Polyketone resin: 70%~90%; Hydroxylated quaternary ammonium salt antistatic agents: 0.5%~5%; Surface-hydroxyl-modified carbon nanotubes: 1%~3%; Graphene microsheets: 0.5%~1.5%; Fluorinated polyetherketone: 3%~6%; Phosphazene flame retardant: 1%~5%; Conductivity modifier: 0.01%~0.2%.

2. The antistatic polyketone composite material according to claim 1, characterized in that, The molecular weight of the polyketone resin is 1,000 to 200,000. The polyketone is a terpolymer of carbon monoxide, ethylene, and propylene, with an propylene insertion rate of 4-8%.

3. The antistatic polyketone composite material according to claim 1, characterized in that, The hydroxylated quaternary ammonium salt antistatic agent is a quaternary ammonium salt containing an alkyl chain of C12~C22 and a hydroxyalkyl group.

4. The antistatic polyketone composite material according to claim 3, characterized in that, The hydroxylated quaternary ammonium salt antistatic agents include one or more of tetradecyl methyl diethylhydroxyammonium bromide, hexadecyl methyl diethylhydroxyammonium bromide, docosyl hydroxypropyl quaternary ammonium salt, dimethyl hydroxyethyl stearamide ethyl quaternary ammonium nitrate, and hexadecyl hydroxyethyl dimethyl ammonium chloride.

5. The antistatic polyketone composite material according to claim 1, characterized in that, The phosphazene flame retardant includes one or more of cyclic phosphazene compounds, linear phosphazene compounds, phosphazene salt compounds, silicon-modified phosphazene compounds, and waterborne phosphazene compounds.

6. The method for preparing the antistatic polyketone composite material as described in claim 1, comprising the following steps: The antistatic polyketone composite material is obtained by melt blending polyketone resin, hydroxylated quaternary ammonium salt antistatic agent, surface hydroxyl-modified carbon nanotubes, graphene microsheets, fluorinated polyether ketone, phosphazene flame retardant and conductivity modifier, and then extruding and granulating.

7. The preparation method according to claim 6, characterized in that, The melt blending temperature is 210~260℃, and ultrasonic dispersion is carried out simultaneously during the melt blending process. The ultrasonic power is 300~500W.

8. A new energy battery component, characterized in that, Including the antistatic polyketone composite material according to any one of claims 1 to 5.

9. The new energy battery component according to claim 8, characterized in that, The new energy battery components include one or more of the following: separator, battery module bracket, electrode protective sleeve, and electrolyte delivery pipeline.

10. A new energy battery, characterized in that, Includes the new energy battery component as described in claim 8 or 9.

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