30results about How to "Improve puncture strength" patented technology

The invention relates to the technical field of battery diaphragms, in particular to a composite coating diaphragm for a lithium ion battery and a preparation method of the composite coating diaphragm, and the preparation method comprises the following steps: coating aramid polymer slurry on a base membrane, and carrying out coagulating bath forming and drying treatment to obtain an aramid coating diaphragm intermediate; the aramid polymer slurry comprises a cross-linked structure aramid polymer solution, a pore-foaming agent and a cosolvent; the weight-average molecular weight of a cross-linked structure aramid polymer in the cross-linked structure aramid polymer solution is 15-30 W; and coating the surface of the aramid fiber coated diaphragm intermediate with a TiO2 treatment solution, and finally performing drying treatment to obtain the composite coated diaphragm. The TiO2 treating fluid is prepared from TiO2 sol and a water-based adhesive. The composite coating diaphragm has higher heat resistance, diaphragm rupture temperature, puncture strength and low water absorption performance; and after the battery is assembled, the battery shows better electrochemical and safety performance.

The invention relates to a polyester composition as well as a preparation method and application thereof. The polyester composition comprises the following components in parts by weight: 50-88 parts of biodegradable polyester, 2-15 parts of polylactic acid and 10-35 parts of mineral filler. The polyester composition provided by the invention has good puncture strength, longitudinal tear strength and transverse tear strength when being prepared into films with different thicknesses, and can keep good puncture strength, longitudinal tear strength and transverse tear strength under the condition that the polyester composition has high content of mineral filler.

The invention provides a basalt fiber reinforced polyethylene diaphragm, a preparation method and application of the basalt fiber reinforced polyethylene diaphragm in a lithium battery, and the method comprises the following steps: 1) carrying out melting treatment and granulation treatment on basalt fibers, polyethylene resin and paraffin oil to obtain basalt fiber reinforced resin particles; and 2) carrying out hydrophilic modification treatment on the basalt fiber reinforced resin particles to obtain the basalt fiber reinforced polyethylene diaphragm. Compared with a traditional diaphragm material, the diaphragm prepared by the method has the advantage that the heat resistance is improved.

The invention relates to the technical field of batteries, in particular to a battery. The battery comprises a positive plate, a negative plate, electrolyte and a diaphragm located between the positive plate and the negative plate, the diaphragm comprises a base material and a ceramic layer located on the surface of one side or two sides of the base material, the ceramic layer comprises inorganic particles, the ceramic layer is of a porous structure, the porous structure comprises holes with the diameter larger than or equal to 0.5 micrometer, and the inorganic particles are distributed in the range of 100 micrometers * 100 micrometers randomly selected on the surface of the ceramic layer. The number of the holes with the diameter larger than or equal to 0.5 micrometer is 10-800, and the coverage rate A1 of the holes with the diameter larger than or equal to 0.5 micrometer in the surface of the ceramic layer is 10%-50%; the electrolyte comprises an organic solvent, and the organic solvent comprises at least two of dimethyl carbonate, ethyl methyl carbonate, propylene carbonate, ethylene carbonate, diethyl carbonate, propyl propionate, ethyl propionate and ethyl acetate. The battery disclosed by the invention can have relatively high quick-charge cycle performance and rate capability under the condition that the safety performance is not influenced.

The invention discloses a puncture-resistant biodegradable film bag and a preparation method thereof. The puncture-resistant biodegradable film bag is prepared from the following raw materials in parts by weight: 50-80 parts of biodegradable polyester, 1-20 parts of a modifier and 10-35 parts of an inorganic filler, wherein the total part number of the three raw materials is 100; the composition further comprises 0.1-5 parts of a cross-linking agent, 0.1-5 parts of an antioxidant and 0.1-1 part of a dispersing agent; the weight-average molecular weight of the puncture-resistant biodegradable material is 100,000-300,000; and the cross-linking agent is at least one of triallyl isocyanurate, trimethylallyl isocyanate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate and triglycidyl tripolyisocyanate. The modifier, the cross-linking agent and the biodegradable polyester have a synergistic effect, and through an electron beam irradiation process, not only can the puncture strength of the film bag be greatly improved, but also the MD tensile strength and the TD tensile strength are also greatly improved.

The invention discloses a sandwich structure electrolyzed water composite diaphragm, a preparation method and application, the diaphragm is composed of a three-layer structure, the first layer is a PTFE / polymer / inorganic nanoparticle composite porous layer, the middle layer is a polymer / inorganic nanoparticle composite porous layer, and the third layer is a PTFE / polymer / inorganic nanoparticle composite porous layer. The preparation method comprises the following steps: firstly, horizontally coating a prepared membrane casting solution on a hydrophilic treated PTFE porous membrane, then flatly laying another hydrophilic PTFE porous membrane on the PTFE porous membrane coated with the membrane casting solution, and standing to form a three-layer composite wet-state membrane; and putting into a coagulating bath to form the electrolyzed water composite diaphragm with a sandwich structure. The implementation process is simple, the operation steps are easy to repeat, through innovation of the composite membrane structure, the scraping resistance, the bending resistance, the tensile property and the tear resistance of the diaphragm are enhanced, meanwhile, a three-dimensional porous structure is formed, and the surface resistance of the diaphragm and the hydrogen production energy consumption of an electrolytic cell can be effectively reduced.

The invention provides a preparation method of a multilayer reinforced alkaline water composite diaphragm. The preparation method comprises the following steps: S1, preparing raw materials; the raw materials comprise polysulfone, zirconium dioxide, polyethylene glycol, polyvinylpyrrolidone, potassium chloride, methyl pyrrolidone and a PEEK woven net; s2, preparing slurry; s3, preparing a film; the high-temperature alkaline electrolytic cell diaphragm has the beneficial effects that the PEEK woven mesh is adopted as the reinforced framework layer, the melting point of a PEEK material is 340 DEG C, the melting point of pps is about 280 DEG C, the heat resistance of the PEEK material is obviously higher than that of pps mesh cloth, and the heat resistance and safety of the diaphragm are greatly improved when the diaphragm is applied to a high-temperature alkaline electrolytic cell (greater than 100 DEG C) in the future.

The invention provides waterborne polyurethane for medical gloves as well as a preparation method and application of the waterborne polyurethane, and belongs to the technical field of medical materials. The preparation method comprises the following steps: uniformly mixing 35-40 parts of polyurethane A, 14-18 parts of polyurethane B, 8-12 parts of a surfactant, 7-11 parts of a modified filler, 2-5 parts of caprolactam and 70-75 parts of deionized water, and carrying out ultrasonic treatment for 15-20 minutes to obtain the waterborne polyurethane for the medical gloves. The waterborne polyurethane disclosed by the invention is high in storage stability, good in mechanical property and excellent in radiation resistance and solvent resistance.

The invention provides a lithium ion battery internal short circuit prevention diaphragm and a preparation method thereof, the diaphragm comprises a foaming material and a polymeric membrane, and the foaming material is dispersed on the polymeric membrane. The diaphragm can ensure that once internal short circuit occurs in the lithium ion battery, local internal short circuit can cause heating and temperature rise of an internal short circuit area, and when the temperature reaches a certain temperature, the foaming material on the polymeric membrane is heated to rapidly expand, so that positive and negative electrodes in short circuit are separated, and the internal short circuit reaction is stopped; therefore, internal short circuit is avoided and further deterioration of the situation is prevented.

This invention relates to the field of battery technology, specifically to a separator layer and a battery including the separator layer. The separator layer comprises nanofibers and inorganic particles embedded within the nanofibers. The separator layer of this invention combines high air permeability and high puncture strength; batteries including the separator layer of this invention have low self-discharge levels, low impedance, and high safety performance.

The invention discloses a lodging-resistant high-yield silicon fertilizer for naked oats and application of the silicon fertilizer, and relates to the technical field of silicon fertilizer application for oats. The invention relates to a lodging-resistant high-yield silicon fertilizer for naked oat. The application amount of effective silicon in the silicon fertilizer is 60-90kg / hm < 2 >; and the silicon fertilizer is analytically pure sodium silicate Na2SiO3. 5H2O. The invention also discloses a preparation method of the According to the lodging-resistant high-yield silicon fertilizer for avena nuda and the application of the silicon fertilizer, when the application amount of the silicon fertilizer is 60-90 kg / hm < 2 >, the lodging-resistant performance of the avena nuda can be remarkably improved, and the main effect is that the breaking resistance and the puncture strength of stalks are improved; the biomass and the yield of the naked oat are increased, which are mainly embodied in that the ear length is increased, the number of effective ears per unit area is increased, and the number of spikelet per plant, the number of grains per plant, the weight of grains per plant, the weight of thousand grains and the yield of grains are increased.

The utility model belongs to the technical field of medical instruments, and discloses a puncture guide wire which comprises a puncture body and a rigidity balancing sleeve. The puncture body comprises at least two first puncture sections which are connected in sequence, and in every two adjacent first puncture sections, the diameter of the first puncture section close to the far end of the puncture guide wire is smaller than that of the other first puncture section; the number of the rigidity balance sleeves is at least two, the rigidity balance sleeves correspond to the first puncture sections in a one-to-one mode, the corresponding first puncture sections are fixedly sleeved with the rigidity balance sleeves, and in every two adjacent rigidity balance sleeves, the outer diameter of the rigidity balance sleeve close to the far end of the puncture guide wire is larger than that of the other rigidity balance sleeve. The flexural rigidity of the rigidity balance sleeve close to the far end of the puncture guide wire is larger than that of the other rigidity balance sleeve. Puncture guide wires with different strengths do not need to be replaced repeatedly, so that the operation time is saved, and the operation risk is reduced. And the size of the included angle opening of the U-shaped puncture head cannot be increased along with the feeding of the puncture guide wire, so that the blood vessel is prevented from being burst.

The invention discloses a polyethylene and TPO (thermoplastic polyolefin) material modified by ionic liquid as well as a preparation method and application of the polyethylene and TPO material. The polyethylene modified by utilizing the ionic liquid is prepared from raw materials including polyethylene, an initiator and the organic ionic liquid, the TPO material disclosed by the invention is prepared from the following raw materials: PP, polyethylene modified by utilizing ionic liquid, an elastomer, a filler, an antioxidant and a light stabilizer. According to the invention, the organic ion modified polyethylene is firstly prepared by using the ionic liquid, and then the organic ion modified polyethylene is added into the TPO, so that the tensile strength, elongation at break and puncture resistance of TOP can be remarkably improved, and meanwhile, relatively low bending modulus and hardness are maintained; and the low-temperature bending property of the material added with the ionic liquid modified HDPE is not influenced by HDPE crystallization, and the material is free of cracks after being bent at low temperature. Therefore, the TPO material with excellent mechanical properties is obtained.

The invention provides polymer nanofiber formed particles, a preparation method thereof and lithium battery diaphragm coating slurry comprising the polymer nanofiber formed particles. The polymer nanofiber formed particles are prepared by the preparation method, and the method comprises the following steps: preparing polymer nanofibers into a dispersion liquid, stirring, homogenizing and emulsifying, drying at low temperature, heating and crystallizing, crushing and sieving, and demagnetizing, so as to obtain the polymer nanofiber formed particles. The viscosity of the dispersion liquid is less than 500 cp. The invention further provides lithium battery diaphragm coating slurry, and a preparation method of the lithium battery diaphragm coating slurry comprises the following steps: mixing the polymer nanofiber molding particles, a water-based dispersant and pure water to obtain dispersed slurry, uniformly mixing the dispersed slurry with an anti-settling agent aqueous solution, grinding to obtain ground slurry, mixing the ground slurry, an adhesive and a wetting agent, and uniformly stirring to obtain the lithium battery diaphragm coating slurry. The lithium battery diaphragm coating slurry is obtained. The coating slurry prepared from the polymer nanofiber formed particles provided by the invention has the excellent characteristics of high solid content and low viscosity, so that the comprehensive performance of the diaphragm is remarkably improved.

The present invention belongs to the field of lithium ion technology, and discloses a lithium battery separator, including an inorganic coating, a polyethylene layer and a polypropylene layer, the two sides of the inorganic coating are respectively bonded with polyethylene layers, the side of the polyethylene layer facing away from the inorganic coating is bonded with a polypropylene layer, and a flame retardant capsule is arranged in the polyethylene layer, and the flame retardant capsule includes a polyvinylidene fluoride coating layer and a triphenyl phosphate flame retardant arranged in the polyvinylidene fluoride coating layer. A lithium battery separator provided by the present invention has a polyethylene layer and a polypropylene layer bonded on both sides of the inorganic coating, so that the thickness of the lithium battery separator is increased, and because the inorganic coating is sandwiched in the middle, the safety of the separator is greatly increased, and the effective high-temperature closed-cell mechanism of PP and PE and the embedding of the flame retardant capsule improve the large self-discharge phenomenon of the lithium battery and the safety hazards such as fire and explosion caused by short circuit.

The present invention relates to a pouch-type battery case and a pouch-type secondary battery, the pouch-type battery case for accommodating an electrode assembly formed by stacking a positive electrode, a separator, and a negative electrode and comprising a pouch film laminate including: a sealing layer formed as an innermost layer from a first polymer, a gas barrier layer formed as an innermost layer from a second polymer, and a surface protection layer formed as an innermost layer from a third polymer; the surface protection layer is formed by a second polymer as an outermost layer; the gas barrier layer is laminated between the surface protection layer and the sealing layer and is formed of an aluminum alloy thin film having a thickness of 60 [mu] m to 100 [mu] m and a grain size of 10 [mu] m to 13 [mu] m.

A polarizing film in which fracture along the absorption axis direction is suppressed is provided. The polarizing film of the present invention is composed of a polyvinyl alcohol-based resin film containing a dichroic substance, and the orientation function is 0.30 or less. In one embodiment, the thickness of the polarizing film is 8 μm or less. The polarizing plate of the present invention comprises: the above-mentioned polarizing film, and a protective layer disposed on at least one side of the polarizing film.

The present invention belongs to the technical field of electrochemical energy storage, and discloses the preparation and application of a modified ultra-thin cellulose diaphragm. The present invention adopts a vacuum filtration method to directly filter cellulose or cellulose modified by functional materials onto a filter membrane substrate, and peels off the filter membrane substrate after drying to construct a modified ultra-thin cellulose diaphragm. The modified ultra-thin cellulose diaphragm has the functions of high puncture strength, promoting the homogenization of the electric field and ion field on the surface of the zinc negative electrode during zinc ion deposition, optimizing the orientation of the zinc deposition crystal plane, and reducing the nucleation barrier, so as to achieve the effect of inhibiting the growth of zinc dendrites. Thereby realizing a high-stability, long-cycle-life aqueous zinc-based energy storage system, which is of great significance to promoting the practical application of aqueous zinc-based energy storage systems.

The invention relates to the technical field of decorative films, in particular to a high-strength PP material and application thereof in decorative films. The prepared high-strength PP material is applied to a decorative film, and the technical problems that the decorative film is low in mechanical strength and poor in anti-corrosion and antibacterial performance are solved. The high-strength PP material is finally prepared by preparing the base layer and preparing the pigment layer and the wear-resistant layer on the surface of the base layer, and the high-strength PP material is applied to the surface of wooden furniture to obtain the decorative film. The raw material dosage of the base layer is changed; adjusting the dosage of raw materials for preparing the bis (pinacol) diboronic acid modified ethyl acrylic acid; the dosage of the cubic boron nitride, the wear-resistant layer and the oxabicyclo heptane is changed; cubic boron nitride is used for loading antibacterial liquid; performing plasma treatment on the PP material; the prepared high-strength PP material is good in mechanical property, and the decorative film is high in strength and good in antibacterial property.

The utility model discloses an anti-puncture rubber tire which comprises a rubber tire main body, the rubber tire main body comprises a tread, a sidewall and a bead, a first bulletproof fiber layer is fixedly arranged on the inner side surface of the tread, a second bulletproof fiber layer is fixedly arranged on the inner side surface of the first bulletproof fiber layer, and the second bulletproof fiber layer is fixedly arranged on the inner side surface of the second bulletproof fiber layer. A cord fabric layer is fixedly arranged on the inner side face of the second bulletproof fiber layer, and an inner layer is fixedly arranged on the inner side face of the cord fabric layer; the two bulletproof fiber layers are additionally arranged between the tread and the cord fabric layer, so that the structural strength of the tread is improved, the puncture-proof strength of the tread is improved, holes can be automatically repaired by the polymer composite material of the inner layer, the driving safety is improved, the tread, the tire side wall and the tire bead can resist certain foreign matter puncture external force through the multiple groups of steel wire bundles, and the service life of the tire is prolonged. Therefore, the anti-pricking purpose is achieved.

This invention belongs to the field of polyethylene film technology and discloses a puncture-resistant linear low-density polyethylene composition and film. The polyethylene composition contains component A and component B, wherein component A is metallocene linear low-density polyethylene with a density of 0.90-0.92 g / cm³. 3 Component B: Linear low-density polyethylene, whose comonomer distribution, as determined by temperature leaching curve analysis, exhibits peaks above 93°C, and the proportion of molecules leached above 93°C is not less than 75%; based on the total weight of components A and B, the weight content of component B is 10-30 wt%. The polyethylene composition and film of the present invention exhibit excellent puncture resistance.

The application relates to the technical field of building waterproof materials, in particular to SBS elastomer modified asphalt waterproof coiled material and a production process thereof; the SBS elastomer modified asphalt waterproof coiled material comprises a bottom isolation layer, a lower coating cover layer, a polyester base reinforcing layer, an upper coating cover layer and a top isolation layer, and is formed through a composite molding step; the system combines multilayer co-extrusion and interface anchoring to construct an overall layered interlocking structure; the core is to utilize SBS and hydrogenated styrene-butadiene-styrene block copolymer dynamic micro-crosslinking to form a three-dimensional semi-interpenetrating polymer network, introduce microwave pre-activation waste rubber powder to produce mechanical interlocking, and supplement coupling modified talc powder to strengthen the interface anchoring of the coating material and the pre-impregnated base layer; through multiple phase interface synergy and network micro-crosslinking, the application improves the puncture resistance and weather resistance and crack resistance of the coiled material, and overcomes the technical defects of interlayer peeling and aging cracking under complex working conditions.

The invention belongs to the technical field of batteries, and discloses a battery diaphragm and a preparation method thereof. The battery diaphragm comprises a non-woven fabric membrane, the outer wall surface of the non-woven fabric membrane is coated with a ceramic slurry coating, and the ceramic slurry coating comprises a solvent, an adhesive and an ionic liquid modified halloysite tube. The halloysite tube modified by the ionic liquid is used for preparing the slurry, so that the nano particles can be uniformly dispersed in a polymer adhesive, and the problem that the nano particles are easy to aggregate is avoided. Due to the entanglement effect of organic chains on the peripheries of the nano particles and polymer adhesive chain segments, the structural stability and mechanical performance of the coating can be greatly improved, and the puncture-resistant strength of the diaphragm is improved. Meanwhile, the quaternary ammonium salt contained in the modified halloysite tube can also generate an adsorption effect on anions in the electrolyte, so that the transmission behavior of lithium ions is improved, the transference number of the lithium ions is increased, the concentration polarization phenomenon is weakened, the growth of lithium dendrites is inhibited, and the cycle life of a corresponding battery is further prolonged.

The utility model relates to the field of medical apparatus and instruments, and the utility model discloses a simple sampling forceps of multi -functional, including the shell, and its both ends are equipped with the opening, puncture needle, and the shell is penetrated through the both sides opening, and its front end is equipped with the sampling mouth, outer sheath, the sleeve is established on puncture needle, push handle, and the solid is established at puncture needle rear end, and with shell inner wall sliding cooperation, spring, and the clamping is established between shell inner wall front side and push handle front end, is used for driving puncture needle reset, limiting component sets up between push handle and shell, is used for fixing the front travel of puncture needle. The utility model structure is simple, and the operation is simple, is applicable to the operation field situation such as suturing, sampling, surgical area flushing, can improve the operation efficiency.

The application provides a single battery, an energy storage device and an energy storage system. The single battery comprises a shell having an open receiving cavity, and an electric core assembly arranged in the receiving cavity. The electric core assembly comprises a plurality of winding cores connected in parallel, and the winding cores are arranged in sequence along the thickness direction of the winding cores. The winding cores comprise a first winding core and a second winding core, and the first winding core is closer to the shell than the second winding core along the arrangement direction of the winding cores. The first winding core comprises a first diaphragm, and the second winding core comprises a second diaphragm. The puncture strength of the first diaphragm is greater than the puncture strength of the second diaphragm, and the thermal shrinkage rate of the first diaphragm is greater than the thermal shrinkage rate of the second diaphragm.

The present application relates to a laminate for an electric power storage device outer packaging material, and provides a laminate for an electric power storage device outer packaging material capable of obtaining sufficient moldability. A laminate for an electric power storage device outer packaging material (1) of the present application is characterized by comprising: a barrier layer (3) made of metal; a base material layer (2) formed of a heat-resistant resin, which is laminated to an outer side surface of the barrier layer (3); and a sealing layer (4) formed of a heat-fusible resin, which is laminated to an inner side surface of the barrier layer (3), the base material layer (2) is composed of a polyester film layer (21) as an outer side layer and a polyamide film layer (22) as an inner side layer, in terms of the polyester film layer (21), the sum of the tensile breaking strength in the MD and the tensile breaking strength in the TD is 500 MPa to 600 MPa, and the ratio of the tensile breaking strength in the TD to the tensile breaking strength in the MD is 0.8 to 1.1, and the tensile breaking elongation in the MD and the tensile breaking elongation in the TD are 110% to 200%. Here, MD: mechanical flow direction, TD: direction orthogonal to the MD.

The invention discloses a puncture-resistant dairy product packaging film and a production method thereof. The film comprises the following steps: subjecting a base film to ultrasonic treatment, and then subjecting the base film to plasma treatment, wherein during the ion treatment, the electrode distance is 3-4 cm, the oxygen flow rate is 0.5-1.5 mL / min, the vacuum degree is 12-15 Pa, the discharge time is 10-20 s, and the discharge voltage is 100-200 V, so as to obtain a pre-treated base film; adding nano cellulose to tetrahydrofuran and dispersing the film uniformly, and then adding styrene-butadiene-styrene block copolymer, dendritic polyamide-amine and nano graphene oxide and stirring the film uniformly to obtain a spraying liquid; spraying the spraying liquid on the outer side of the pre-treated base film in an ethanol vapor atmosphere, waiting for the tetrahydrofuran to completely volatilize to obtain a protective layer, and drying the film at room temperature; exhausting the air, subjecting the inner side of the pre-treated base film to corona treatment, heat treating the film at 100-130° C. for 5-10 min, and cooling the film to room temperature to obtain the puncture-resistant dairy product packaging film.

The application discloses a kind of high light transmittance biobased degradable medical protective film and preparation method thereof, belong to the technical field of protective film processing, for solving the technical problems that light transmittance, puncture resistance, antibacterial property and degradable property of medical protective film in prior art need to be further improved, a kind of high light transmittance biobased degradable medical protective film, including two outer surface layers and toughening core layer between two outer surface layers, wherein the thickness of outer surface layer is 10-12 μm, the thickness of toughening core layer is 50-60 μm.The application is mainly with PBAT, PLA and cellulose, with epoxy modified PBAT as core compatibilization and toughening component, supplemented with ammoniated cellulose and antibacterial cellulose, and with the aid of three-layer co-extrusion structure to make antibacterial site obtain efficient exposure, while improving the light transmittance and puncture resistance of medical protective film, improve the antibacterial and degradable property of protective film.

The utility model discloses a kind of lithium ion battery separators prepared using inorganic organic composite material, specifically related to lithium ion battery field, including battery and the protective film of surface setting thereof, battery inside is provided with positive pole, separator and negative pole, and positive pole, separator and negative pole are sequentially arranged from inside to outside, the surface of the separator is provided with porous substrate, and the inside of porous substrate is provided with first coating, second coating and ceramic coating, the utility model is fused below 130 DEG C due to temperature-sensitive polymer microsphere, the air permeability value is promoted to 3500s / 100ml above from 150-300s / 100ml, can quickly block ion transmission path, simultaneously, by nano fiber network and ceramic particle form three-dimensional skeleton, after 1 hour is baked at 180 DEG C, MD direction shrinkage rate≤5%, again using substrate and coating between setting polydopamine coating layer, to enhance interface bonding force, puncture strength>3000g, greatly improve the puncture strength of battery separator.

The present invention relates to the technical field of polymer materials, and specifically to a block copolymer modified para-aramid polymer solution and a preparation method and application thereof, wherein the preparation method comprises: dissolving a solubilizing salt into an organic solvent under an inert gas atmosphere to obtain the polymer solution; adding a third monomer and terephthaloyl chloride to the polymer solution, controlling the reaction temperature to perform a pre-condensation reaction, and obtaining an amino-terminated oligomer system; adding p-phenylenediamine and terephthaloyl chloride to the oligomer system, and controlling the stirring reaction temperature to perform a block copolymerization reaction under stirring conditions; after the block copolymerization reaction is completed, adding a neutralizer to neutralize the acidic substances generated during the reaction, and finally obtaining a modified para-aramid polymer solution in a neutral environment. The polymer solution is applied to the field of lithium battery separators to obtain a modified aramid coated separator with excellent heat shrinkage performance, high film breaking temperature, porous structure, and high puncture resistance.