57results about How to "Excellent heat shrinkage resistance" patented technology

The invention relates to the field of lithium-ion batteries, in particular to a method for preparing a composite lithium-ion battery separator through electrostatic spinning/electrostatic spraying. The method specifically includes the steps of firstly, adding high molecular polymer into an organic solvent, dissolving the high molecular polymer through mechanical stirring to form a transparent solution, and obtaining an electrostatic spinning solution; secondly, mixing inorganic nanometer particles with the high molecular polymer and adding the mixture into the organic solvent, and conducting mechanical stirring to obtain inorganic nanometer particle suspension liquid; thirdly, conducting electrostatic spinning on the spinning solution prepared in the first step to prepare a lower layer nanometer fiber film, and enabling the inorganic nanometer particle suspension liquid prepared in the second step to be deposited on the lower layer nanometer fiber film through electrostatic spraying to obtain an interlayer; finally, receiving an electrostatic spun nanometer fiber layer on an inorganic particle layer to obtain the composite lithium-ion battery separator. The composite lithium-ion battery separator has the high imbibing rate and good electrochemical stability under the room temperature and has good heat shrinkage resistance performance at the same time.

The invention discloses a heat-not-burn cigarette smoke cooling material and application thereof. The heat-not-burn cigarette smoke cooling material is prepared from, by mass, polymer 50-75%, layerednano material 5-15%, fibrous nano material 4-15%, phase change material 5-10% and metal powder 3-10% by adopting screw extrusion processing. The heat-not-burn cigarette smoke cooling material has highheat resistant shrinkage by means of addition of the layered nano material and the fibrous nano material, and the defect that a polylactic acid cooling material shrinks due to heat is avoided; the exogenous phase change material is added, so that the heat-not-burn cigarette smoke cooling material has a better cooling effect; in addition, the heat-not-burn cigarette smoke cooling material has a low interception rate of smoke, and the suction experience is not affected basically.

The invention relates to a lithium ion battery diaphragm with a hydrophilic cross-linking surface layer and the manufacture method of the lithium ion battery diaphragm. The battery diaphragm is a polyolefin microporous film; and the manufacture method comprises: (1) surface pretreatment of the polyolefin microporous film, (2) surface grafting reaction of the polyolefin microporous film, (3) cross-linking of a surface hydrophilic layer of the polyolefin microporous film; and (4) post-treatment of the polyolefin microporous film. The prepared microporous film can still keep the original porosity and penetration rate, and is improved obviously in the surface hydrophilicity so as to facilitate the full wetting of electrolyte on the surface of the diaphragm, thereby lowering the internal resistance of the lithium ion battery and realizing the excellent cycling performance and higher charging-discharging efficiency of the battery. Meanwhile, the heat-resistant contraction performance and the size stability of the diaphragm under heating are improved, thereby improving the use safety of the lithium ion battery.

Object of the present invention is to provide a production method of a highly crystalline silver powder containing powder particles in fine particle region and having a good particle size distribution as well as the highly crystalline silver powder obtained by the production method. In order to achieve the object, the present invention adopts a production method characterized in that the method comprises preparation of a first aqueous solution in which gelatin, silver nitrate and nitric acid are dissolved in water, preparation of a second aqueous solution in which L-sorbic acid and/or ascorbic acid and a water-soluble organic acid are dissolved, adding of the second aqueous solution slowly to mix with the first aqueous solution, stirring of the mixture to grow the silver particles after finishing the mixing, keeping of the mixture still to settle the silver particles, discarding of the supernatant, filtration and rinsing to obtain the highly crystalline silver powder.

A microporous polyolefin membrane comprising a polyethylene resin, and having (a) a shutdown temperature of 135° C. or lower, at which the air permeability measured while heating at a temperature-elevating speed of 5° C./minute reaches 1×10⁵ sec/100 cm³, (b) a maximum melting shrinkage ratio of 40% or less in a transverse direction in a temperature range of 135 to 145° C., which is measured by thermomechanical analysis under a load of 2 gf and at a temperature-elevating speed of 5° C./minute, and (c) a meltdown temperature, at which the air permeability measured while further heating after reaching the above shutdown temperature becomes 1×10⁵ sec/100 cm³ again, being 150° C. or higher.

The invention provides a polyethylene composition for preparing a heat-shrinkage-resistant lithium ion battery diaphragm. The composition comprises high-molecular polyethylene, ultra-high-molecular polyethylene and an optional additive. The lithium ion battery diaphragm prepared from the composition has high heat shrinkage resistance, high tensile strength, high puncture strength, relatively high diaphragm-rupture temperature and relatively low closed-hole temperature, thereby ensuring safety in preparation and usage of the lithium ion battery.

An object of the present invention is to provide a fiber made of polylactic acid and having excellent strength, heat resistance and heat shrinkage resistance and a manufacturing method thereof.

The present invention relates to the fiber is made of a composition which comprises (i) poly(L-lactic acid) having a weight average molecular weight of 50,000 to 300,000 (component A), (ii) poly(D-lactic acid) having a weight average molecular weight of 50,000 to 300,000 (component B) and (iii) 0.01 to 5 parts by weight of a phosphate metal salt (component C) based on 100 parts by weight of the total of the components A and B and has a strength of 2.5 to 10 cN/dTex and a manufacturing method thereof.

The invention belongs to the technical field of lithium ion batteries, and relates to an ultrafine diamond coated diaphragm, a preparation method thereof, and a lithium ion battery using the diaphragm. The ultrafine diamond coated diaphragm is prepared through the following steps: coating a base film with a slurry, and drying the coated base film, wherein the slurry contains, by mass, 65-85% of ultrafine diamond micro-powder and am inorganic filler, 10-25% of a filler and 3-15% of glue; and the mass of the ultrafine diamond micro-powder is 0.5-100% of the total mass of the ultrafine diamond micro-powder and the inorganic filler. The diaphragm makes micron-sized diamond crystal particles uniformly dispersed on the surface of the base film, so the micro-porous structure of the diaphragm is effectively strengthened, and the heat shrinkage resistance and the puncture strength are improved. The lithium ion battery using the diaphragm improves the transfer state of lithium ions in an electrode sheet interface, inhibits the lithium ions from accumulating into lithium element dendrite after the lithium battery is repeatedly circulated, and improves the safety and the cycle performances ofthe battery.

The invention discloses a preparation method of a self-cooled and hole-closing-resistant lithium ion battery diaphragm, and belongs to the technical field of the battery diaphragm. The slurry layer is arranged at one side end surface or two side end surfaces of a basement membrane, thereby obtaining the self-cooled and hole-closing-resistant lithium ion battery diaphragm after the drying; the slurry layer is the ceramic slurry or the erythritol modified ceramic slurry, the erythritol modified ceramic slurry is at least coated at one side end surface, and the specific method for preparing the erythritol modified ceramic slurry is disclosed. The preparation method disclosed by the invention provides the stable and efficient process of the self-cooled and hole-closing-resistant lithium ion battery diaphragm; the prepared erythritol modified ceramic slurry has low shrinkage and high security at the high temperature of the ceramic slurry.

The invention discloses a preparation method of a heat shrinkage-resistant lithium-ion battery separator. The method comprises the steps of melting and mixing a polyethylene composition, a pore-forming agent and an optional additive, extruding a cast film and casting a thick sheet through a first sheet casting roller and a second sheet casting roller; and carrying out longitudinal stretching through a preheating roller, a stretching roller and a cooling roller, carrying out first transverse stretching through a first preheating zone, a first stretching zone and a first cooling zone, carrying out extracting, pore-forming and drying and then carrying out second transverse stretching through a second preheating zone, a second stretching zone and a second cooling zone to obtain the heat shrinkage-resistant lithium-ion battery separator. The preparation method of the heat shrinkage-resistant lithium-ion battery separator is simple and convenient to operate, high in controllability and wide in application; and the battery separator prepared by the method has excellent heat shrinkage resistance and good overall performance.

The invention discloses a preparation method for a battery diaphragm with three kinds of microporous structures. The preparation method comprises the steps of performing fusing and mixing on a polyethylene composition, a pore-forming agent and an optional additive; extruding a cast film, and casting a thick sheet through a first sheet-casting roller and a second sheet-casting roller; next, performing longitudinal stretching through a preheating roller, a stretching roller, and a cooling roller; performing transverse stretching for the first time by passing through a first preheating region, a first stretching region and a first cooling region; performing extracting and pore-forming, and drying; and performing transverse stretching for the second time by passing through a second preheating region, a second stretching region and a second cooling region to obtain the battery diaphragm with the three kinds of microporous structures. The preparation method for the battery diaphragm with the three kinds of microporous structures is simple and convenient to operate, high in controllability and wide in application; and the battery diaphragm prepared by the method is good in comprehensive performance.

The invention discloses a heat-shrinkage-resistant lithium ion battery diaphragm and a pore-forming agent composition adopted by the same. The pore-forming agent composition comprises an organic pore-forming agent and an inorganic pore-forming agent, wherein the organic pore-forming agent is high-boiling-point low molecular weight organic matter preferably; the inorganic pore-forming agent is water-soluble inorganic nanoparticles preferably; and the pore-forming agent and the optional additive are jointly added to a film-forming material to form a lithium ion battery diaphragm with three kinds of microporous structures through processing of casting pieces. In addition, the heat-shrinkage-resistant lithium ion battery diaphragm has relatively low closed-hole temperature, high heat shrinkage resistance, high tensile strength, high puncture strength and relatively high diaphragm-rupture temperature, thereby ensuring safety in preparation and usage of the lithium ion battery.

The invention relates to a method for preparing an environment-friendly hydrophilic porous coating used for modifying the surface of a porous membrane, and belongs to the technical field of porous membrane coating production. The method includes the following steps: soaking the porous membrane subjected to oxidation by a potassium permanganate/hydrochloric acid solution into a hydroxy ethyl cellulose (HEC) emulsion containing or without containing aluminium oxide particles for 10-14 hours; taking out and placing into a refrigerator for 10-14 hours; then freeze-drying for 2-4 hours to obtain the hydrophilic porous coating. The preparation technology of the coating is simple and environment-friendly; the hydrophilic coating provided by the invention not only has a porous structure but also enables the porous membrane to have excellent wettability; in addition, the heat-shrink resistance of the holes is greatly improved; the coating has a wide application prospect in membrane separation of hydrophilic mediums and the battery industry.

The invention provides a composite diaphragm and an electrochemical device, the composite diaphragm comprises a polymer film and a functional coating arranged on at least one surface of the polymer film, and the functional coating comprises inorganic particles and organic particles; the particle size D901 of the inorganic particles and the particle size D902 of the organic particles meet the following conditions: 0.01 * D902 < = D901 < = 0.5 * D902, and D901 is the particle size of the inorganic particles reaching 90% of the volume accumulation from the small particle size side in the volume-based particle size distribution, and D902 is the particle size of the organic particles reaching 90% of the volume accumulation from the small particle size side in the volume-based particle size distribution. D902 is that in volume-based particle size distribution, the particle size of the organic particles reaches 90% of volume accumulation from the small particle size side. The composite diaphragm has excellent heat-resistant shrinkage performance and interface bonding performance, and can give consideration to high energy density and high safety of an electrochemical device when being applied to the electrochemical device.

The invention discloses a heat shrinkage-resistant lithium ion battery diaphragm, a production method of the diaphragm, and an extractant composition used by the diaphragm. The extractant composition comprises a first extractant and a second extractant, the first extractant is a mixture comprising dichloromethane and phosphate ester, and the second extractant is water. The extractant composition provided the invention has a complete extraction effect on pore forming agents, and realizes less residual of the pore forming agents, and the battery diaphragm with good comprehensive performances can be produced from the pore forming agent, a specific pore forming agent and a specific ratio of macromolecular polyethylene and ultra-macromolecular polyethylene through a specific device by using a processing technology.

The invention discloses a battery diaphragm with three cellular structures, a preparing method thereof, and adopted pore-forming agents and extraction agents. The pore-forming agents include an organic pore-forming agent and an inorganic pore-forming agent, wherein the organic pore-forming agent is high-boiling point micromolecular organic matter, and the inorganic pore-forming agent is nano-particles of water-soluble inorganic salt. The extraction agents include a first extraction agent and a second extraction agent, wherein the first extraction agent is a mixture of dichloromethane and phosphate, and the second extraction agent is water. By the adoption of the pore-forming agents, the size, shape and distribution of formed pores can be well controlled, and the porosity and venting quality of the battery diaphragm can be improved; extraction can be achieved more completely by means of the extraction agents, and the amount of pore-forming agent residue is small; the pore-forming agents, the extraction agents, and macromolecular polyethylene and ultrahigh molecular polyethylene which are matched according to a specific ratio serve as raw materials, and the battery diaphragm with three cellular structures and high comprehensive performance can be obtained through specific devices and processing technology.