58results about How to "Excellent heat shrinkage resistance" patented technology

Disclosed is a composite microporous film which is obtained by applying a liquid mixture containing (a) a fluororesin which can be gelated, (b) a good solvent therefor and (c) a poor solvent therefor having a dipole moment of not more than 1.8 Debye to at least one surface of a polyolefin microporous film and drying it, thereby forming a coating layer composed of a porous body of the fluororesin on the surface. The composite microporous film has columnar through holes in the coating layer, and has an excellent balance among permeability, adhesion to electrodes, mechanical strength, thermal shrinkage resistance, shutdown characteristics and meltdown characteristics.

A battery separator includes a microporous polyolefin membrane and a modifying porous layer laminated on at least one surface of the microporous polyolefin membrane, wherein the microporous polyolefin membrane comprises a polyethylene resin, and the modifying porous layer is laminated on at least one surface of the microporous polyolefin membrane having (a) a shutdown temperature of 135° C. or lower, (b) a rate of air resistance change of 1×104 sec / 100 cc / ° C. or more, and (c) a transverse shrinkage rate at 130° C. of 20% or less.

The invention provides a lithium battery diaphragm for power vehicles. The diaphragm has four layers, the layers are respectively from bottom to top a base diaphragm, a nanometer flame retarding layer, an electrospun nanofiber layer and a thermal closed layer, wherein the base diaphragm is a PET nuclear pore membrane with a thickness of 5 microns-20 microns, the nano meter flame retardant layer is a flame retardant ceramic slurry with a thickness of 0.5 micron-10 microns, the thickness of the electrospun nano-fiber layer is 2 microns-5 microns, and the heat closed layer is a heat-resistant epoxy resin with a thickness of 5 microns-10 microns. The invention also provides a preparation method of the lithium battery diaphragm; the heat-resistance and shrinkage performance of the prepared lithium battery diaphragm can be greatly improved, the thermal stability and thermal closed property are significantly improved, and the security is very good.

The invention aims at providing a process for the production of highly crystalline silver powder which comprises silver particles falling within the fine particle region and has an excellent particle size distribution and highly crystalline silver powder obtained by the process. The aim is attained by a process for the production of highly crystalline silver powder which is characterized by preparing the first aqueous solution containing gelatin, silver nitrate and nitric acid and having a temperature of 45 to 55 C and the second aqueous solution containing erythorbic acid and / or ascorbic acid and a water-soluble organic acid, adding the second aqueous solution mildly to the first aqueous solution, stirring the mixed solution after the completion of the addition to form silver particles through particle growth, allowing the resulting system to stand to settle the silver particles, removing the supernatant, and then subjecting the remainder to filtration and washing to recover the silver particles.

Provided is a battery separator comprising a microporous polyolefin membrane and a modifying porous layer laminated on at least one surface of the microporous polyolefin membrane, wherein the microporous polyolefin membrane comprises a polyethylene resin, and the modifying porous layer is laminated on at least one surface of the microporous polyolefin membrane having (a) a shutdown temperature of 135°C or lower, (b) a rate of air resistance change of 1 × 10 4 sec / 100 cc / °C or more, and (c) a transverse shrinkage rate at 130°C of 20% or less. Provided is a battery separator having high physical stability before the start of shutdown, a high rate of air resistance change after the start of shutdown, excellent heat shrinkage resistance in a temperature range from a shutdown start temperature to a shutdown temperature, a low shutdown temperature, and excellent adhesion to electrode.

Slurry for secondary batteries, which is used for the production of a porous film that has excellent resistance to thermal shrinkage, is provided. The slurry contains non-conductive particles and a water-soluble polymer, wherein the water-soluble polymer is a maleimide-maleic acid copolymer that contains a structural unit (a) represented by general formula (I) and a structural unit (b) represented by general formula (II). In the formulae, R1 represents a hydrogen atom or a substituent selected from the group consisting of an alkyl group having 1-6 carbon atoms, a cycloalkyl group having 3-12 carbon atoms, a phenyl group and a hydroxyphenyl group; and X represents a maleic acid residue which may be neutralized by an ion other than a hydrogen ion, dehydrated or esterified.

The present invention is capable of providing a multilayer porous film which has high adhesion between a base layer and a coating layer and excellent heat resistance and exhibits excellent characteristics when used as a separator for a nonaqueous electrolyte secondary battery. A multilayer porous film which is obtained by laminating a coating layer that contains a filler and a resin binder on at least one surface of a polyolefin resin porous film that serves as a base layer. The ratio of the average particle diameter (Du) of the filler within 25% of the thickness of the coating layer from the surface of the multilayer porous film to the average particle diameter (Db) of the filler within 25% of the thickness of the coating layer from the interface with the base layer, namely, Du / Db is 1.2-10; and the average particle diameter (Du) is 0.5 [mu]m or less.

Disclosed is a process for producing a successively biaxially stretched polyglycolic acid film comprising a step (1) of unidirectionally stretching an amorphous polyglycolic acid sheet at a stretching temperature of 40 to 70 DEG C and at a primary stretch ratio of 2.5 to 7.0 to form a uniaxially stretched film, a step (2) of passing the uniaxially stretched film through an environment having a temperature which is in a range of 5 to 40 DEG C and is at least 5 DEG C below the stretching temperature of the step (1), a step (3) of stretching the uniaxially stretched film in a transverse direction transversely to the stretching direction in the step (1) at a stretching temperature, which is in a range of 35 to 60 DEG C and is at least 3 DEG C above the temperature adopted in the step (2), to form a biaxially stretched film having an area ratio of 11 to 30, and a step (4) of heat treating the biaxially stretched film at 70 to 200 DEG C.

The invention relates to a preparation method of a high-temperature-resistant low-resistivity lithium ion battery diaphragm, and belongs to the technical field of battery diaphragms. A slurry layer is coated on one side end face or two side end faces of a basal membrane; then, after the slurry layer is dried, the high-temperature-resistant low-resistivity lithium ion battery diaphragm is obtained; the slurry layer is ceramic slurry or carbon nano tube modified ceramic slurry; and furthermore, the carbon nano tube modified ceramic slurry is at least coated on one side end face of the basal membrane. The invention further discloses a specific method for preparing the carbon nano tube modified ceramic slurry. By means of the preparation method in the invention, a steady and high-efficiency process is provided for producing the high-temperature-resistant low-resistivity lithium ion battery diaphragm; the prepared carbon nano tube modified ceramic slurry has low shrinkage ratio and high security of the ceramic slurry at high temperature, and also has high electric conductivity at normal temperature and low electric conductivity at high temperature of a carbon nano tube material; therefore, when the high-temperature-resistant low-resistivity lithium ion battery diaphragm is used in the field of electric automobiles, the charging time consumption problem of the electric automobiles can be solved; and the technical support is provided for development of clean energy automobiles.

A polyolefin porous membrane is characterized by comprising a polyethylene resin, and is further characterized in that (a) the shutdown temperature is 135 DEG C or lower which is the temperature at which the gas permeability as measured with heating at a heating rate of 5 DEG C / min reaches 1*10<5> sec / 100 cm<3>, (b) the change rate of the gas permeability is 1*10<4> sec / 100 cm<3> or more, the change rate of the gas permeability is the gradient at the coordinate on the curve representing the dependency of the gas permeability to the temperature when the gas permeability is 1*10<4> sec / 100 cm<3>, (c) the transverse shrinkage factor measured at 130 DEG C through the analysis of heating mechanism at a load of 2gf and a heating rate of 5 DEG C / min is 20% or below.

An object of the present invention is to provide highly crystalline silver powder which is characterized in fine particles, showing high dispersibility, it's particle size distribution is not excessively sharp but relatively broad and crystallites are large; and a method for producing the same. In order to achieve the object, a method for producing highly crystalline silver powder is characterized in that mixing a first aqueous solution and a second aqueous solution, wherein the first aqueous solution contains silver nitrate, a dispersing agent and nitric acid, and the second solution contains ascorbic acid. For dispersing agent, polyvinylpyrrolidone or gelatin is preferred. Highly crystalline silver powder produced by the above-described method is preferred to be a crystallite diameter of 300 Å or more, an average particle diameter D50 in the range from 0.5 μm to 10 μm, and a thermal shrinkage rate for the length direction after heating at 700° C. in the range from −3% to 3%. For ratio D90 / D10 of the silver powder is preferred to be in the range from 2.1 to 5.0.

Provided are: a microporous membrane which contains a polyolefin and a thermoplastic resin (a) having a melting point of 220°C or more, said thermoplastic resin (a) having a needle-like structure; and a method for producing the microporous membrane. Since this microporous membrane uses a polyolefin and a high-melting-point thermoplastic resin having a needle-like structure, this microporous membrane has excellent thermal shrinkage resistance. Consequently, there can be provided a nonaqueous electrolyte secondary battery separator, especially a single layer separator for nonaqueous electrolyte secondary batteries, which has excellent shut-down function and thermal shrinkage resistance.

The invention discloses a heat shrinkage-resistant lithium-ion battery separator, which comprises a first outer layer, a second outer layer and an inner layer clamped between the first outer layer and the second outer layer, wherein the first outer layer, the second outer layer and the inner layer have different micropore structures. The heat shrinkage-resistant lithium-ion battery separator disclosed by the invention has excellent heat shrinkage resistance and good overall performance, has high puncture strength and tensile strength when reaching a relatively low thickness, can be applied to a relatively small battery and is not easily damaged in the installation process; a plurality of physical properties are taken into account; meanwhile, the heat shrinkage-resistant lithium-ion battery separator has good air permeability and porosity and small internal resistance; the capacity and the cycle performance of the battery are improved; and furthermore, the heat shrinkage-resistant lithium-ion battery separator also has relatively low closed pore temperature and membrane rupture temperature and high safety.

The present application provides a thermal crosslinking type slurry for a lithium ion battery, a method for producing the same, an electrode for a lithium ion battery, a separator for a lithium ion battery, a separator / an electrode laminate for a lithium ion battery, and a lithium ion battery. The present application provides the thermal crosslinking type slurry for the lithium ion battery, comprising: a water-soluble poly(meth)acrylamide (A), which is 100% by mole based on the structural unit, wherein the water-soluble poly(meth)acrylamide (A) contains 50% by mole or more of a structural unit derived from the compound (a) having an N-unsubstituted or monosubstituted (meth)acrylamide group; a water-soluble crosslinking agent (A1), wherein the water-soluble crosslinking agent (A1) containsone or more selected from the group consisting of formaldehyde, glyoxal, hexamethylenetetramine, urea-formaldehyde resin, and methylol melamine resin; and water.

The invention discloses a battery separator with three micropore structures. The separator comprises a first outer layer, a second outer layer and an inner layer clamped between the first outer layer and the second outer layer, wherein the first outer layer, the second outer layer and the inner layer have different micropore structures. The battery separator with the three micropore structures disclosed by the invention has a plurality of physical and chemical properties and good overall performance, has high puncture strength and tensile strength when reaching a relatively small thickness, can be used for a relatively small battery, and is not easily damaged in the installation process and has good air permeability and porosity and small internal resistance; the capacity and the cycle performance of the battery are improved; and furthermore, the battery separator also has relatively low closed pore temperature and membrane rupture temperature and high safety.