Abstract: Disclosed is a method for manufacturing a separator for a lithium secondary battery. The method includes (S1) electrospinning a solution in which ?-chitin is dissolved in a solvent on at least one surface of a porous polyolefin substrate having a plurality of pores, and (S2) drying a result of (S1) to form a porous coating layer of ?-chitin nanofibers.

Abstract: A separator of a secondary battery includes a polyolefin-based porous substrate having a thickness of about 8 ?m or less. The total pore volume within the polyolefin-based porous substrate is about 0.45 cc/g to 1.5 cc/g.

Abstract: An electrode assembly manufacturing method according to the present disclosure uses a pre-compressed separator substrate. Therefore, a reduction in thickness of the separator by the pressure applied in a lamination process during the manufacture of an electrode assembly is small. For this reason, the separator of the electrode assembly manufactured by the method exhibits high insulation performance and does not experience a decrease in dielectric breakdown voltage. In addition, even though high pressure is applied during the lamination process, damage to the separator is small, and the processing speed is fast, resulting in process efficiency.

Abstract: A separator substrate, a separator, an electrode assembly, and an electrochemical device are provided. The separator substrate has different surface characteristics of opposite surfaces thereof, and the separator including the same has opposite sides of different adhesion strengths from each other, and has 10% or less of a deviation of electrode adhesion strength.

Abstract: An electrode assembly manufacturing apparatus includes: a wound separator in which two or more layers of separators are stacked and wound; a separator supply unit that individually separates and supplies the two or more layers of separators from the wound separator; a first electrode supply unit that supplies a first electrode; a second electrode supply unit that supplies a second electrode; and a winding unit that individually stacks and winds each separated separator, between the first electrode and the second electrode and on an outer side of the first electrode or the second electrode.

Abstract: A separator according to an aspect of the present disclosure includes a polyolefin-based substrate having a thickness of about 8 ?m or less. The polyolefin-based substrate has a minimum pore size of about 20 nm or more.

Abstract: A crosslinked polyolefin separator which has gels with a longer side length of 50 ?m or more in a number ranging from 0 to 3 per 1 m2 of the separator, and shows a standard deviation of absorbance ratio between the center of the separator and the side thereof ranging from 0.01 to 0.5 is provided. A method for manufacturing the crosslinked polyolefin separator is also provided. The method includes (S1) preparing a polyolefin porous membrane, and (S2) applying a coating solution containing an initiator and alkoxy group-containing vinylsilane onto at least one surface of the porous membrane. The coating solution can permeate even to the inside of exposed pores. Thus, it is possible to provide a crosslinked polyolefin separator in which silane crosslinking occurs uniformly even inside of the pores.

Abstract: A separator for an electrochemical device is provided. The separator comprises: a porous substrate having a plurality of pores, and a porous coating layer positioned on at least one surface of the porous substrate, the porous coating layer including a plurality of inorganic particles and a binder polymer positioned on a whole or a part of the surface of the inorganic particles to connect the inorganic particles with one another and fix the inorganic particles, wherein the binder polymer comprises a first binder polymer and a second binder polymer. The first binder polymer is poly(vinylidene fluoride-co-hexafluoroproyplene) (PVdF-HFP), and the second binder polymer is poly(vinylidene fluoride-co-tetrafluoroethylene) (PVdF-TFE). The first binder polymer has an electrolyte uptake of 80-165%, and the second binder polymer has an electrolyte uptake of 20-40%. An electrochemical device including the separator is also disclosed.

Abstract: A separator for an electrochemical device is provided. The separator comprises a porous substrate having a plurality of pores, and a porous coating layer positioned on at least one surface of the porous substrate, the porous coating layer including a plurality of inorganic particles and a binder polymer positioned on a whole or a part of the surface of the inorganic particles to connect the inorganic particles with one another and fix the inorganic particles, wherein the binder polymer comprises a first binder polymer and a second binder polymer. The first binder polymer has an electrolyte uptake of 80-165%, and the second binder polymer has an electrolyte uptake of 20-40%. An electrochemical device including the separator is also disclosed.

Abstract: A polyolefin separator is provided in the present disclosure. The polyolefin separator includes a polyolefin porous substrate including a plurality of fibrils and pores formed by the fibrils draped across one another. A coating layer surrounding the outer side of the fibrils is contained in the polyolefin porous substrate and the coating layer includes a crosslinked polymer, wherein the polyolefin separator having the coating layer has a change in air permeability of 20% or less and a change in basis weight of 4% or less, as compared to the polyolefin porous substrate. A method for manufacturing the polyolefin separator and a secondary battery including the polyolefin separator are also disclosed.

Abstract: A separator according to the present disclosure has an organic/inorganic composite porous coating layer on a surface of a polymer substrate, wherein the organic/inorganic composite porous coating layer includes a first region including a larger amount of inorganic particles and a second region including a smaller amount of inorganic particles so that heat resistance at the side of the battery is improved by the first region, thereby solving a short circuit problem caused by shrinkage at two ends of the separator.

Abstract: Disclosed is a separator and an electrochemical device including the same. The separator includes a porous polyolefin substrate having improved wettability and a porous coating layer having high adhesive property to the porous polyolefin substrate. Specifically, the separator includes the porous polyolefin substrate and the porous coating layer on at least one surface of the porous polyolefin substrate. The porous polyolefin substrate includes a crosslinked polyolefin resin. The crosslinked polyolefin resin includes a silicon-containing organic group grafted onto a polyolefin chain. The porous coating layer includes inorganic particles and a binder polymer. The inorganic particles include boehmite (AlO(OH)).

Abstract: A separator substrate, a separator including the separator substrate, an electrode assembly including the separator, and an electrochemical device including the electrode assembly. The separator substrate has a surface roughness value (Sa) of from 80 nm to 160 nm on at least one surface. Accordingly, a separator using the separator substrate maintains high adhesive strength, and has improved wear resistance.

Abstract: The present disclosure relates to a system for determining the shut-down temperature and melt-down temperature of a separator. The system includes a jig having a through-hole, a heating unit, a temperature sensor, a controlling unit and an air permeability-determining unit. In this manner, it is possible to provide a novel system for determining the shut-down temperature and melt-down temperature of a separator by using the air permeability (Gurly value) of the separator.

Abstract: A separator substrate, a separator comprising the same, and an electrochemical device comprising the same are provided. The separator substrate comprises a crosslinked polyolefin resin and chromium (Cr), wherein the crosslinked polyolefin resin comprises a silicon-containing organic group grafted to a polyolefin chain, a gel fraction of the separator substrate is 3% to 80%, a standard deviation (?d) of thickness measured in at least 100 random points is 0.5 ?m or less, and a number of spots having a long side length of 50 ?m or more per m2 is 10 or less.

Abstract: The present disclosure provides a method for manufacturing a separator for a lithium secondary battery. The method includes a step (S1) of preparing a slurry in which binder polymer particles and inorganic particles are dispersed in an aqueous dispersion medium, and a step (S2) of forming a porous coating layer by applying and drying the slurry on at least one surface of a porous polyolefin polymer substrate having a plurality of pores, in which the porous polyolefin polymer substrate has a thickness of 9 ?m or less, the porous polyolefin polymer substrate has an average pore size of 30 nm or less, and the binder polymer particles remain in an amount of 0.5 g/m2 or less in the porous polyolefin polymer substrate after the porous coating layer is peeled off by a method of attaching and detaching 3M Scotch tape three times.

Abstract: A crosslinked polyolefin separator and a method of making the same are disclosed herein. The method includes mixing a polyolefin, a diluting agent, an initiator, a crosslinking catalyst, and inorganic particles surface treated with an alkoxysilane containing a carbon-carbon double bonded group in an extruder to obtain a mixture, and then reactively extruding the mixture to form an extruded silane-grafted polyolefin composition; molding and orienting the extruded silane-grafted polyolefin composition in the form of an oriented sheet; extracting the diluting agent from the oriented sheet to obtain a porous membrane; thermally fixing the porous membrane to obtain a thermally fixed porous membrane; and crosslinking the thermally fixed porous membrane in the presence of moisture.

Abstract: The present disclosure provides a method of manufacturing a separator for a lithium secondary battery, the method including a step (S1) of preparing a slurry in which a binder polymer is dissolved and inorganic particles are dispersed, the slurry being prepared by adding and mixing the binder polymer and the inorganic particles in a solvent, and a step (S2) of forming a porous coating layer by applying and drying the slurry on at least one surface of a porous polyolefin polymer substrate having a plurality of pores. The thickness of the porous polyolefin polymer substrate is 9 ?m or less, the D90 particle size of the inorganic particles dispersed in the slurry is 3 ?m or less, and the surface roughness Ra of the porous coating layer is 50 to 500 nm.

Abstract: A polyolefin separator is provided in the present disclosure. The polyolefin separator includes a polyolefin porous substrate including a plurality of fibrils and pores formed by the fibrils draped across one another. A coating layer surrounding the outer side of the fibrils is contained in the polyolefin porous substrate and the coating layer includes a crosslinked polymer, wherein the polyolefin separator having the coating layer has a change in air permeability of 20% or less and a change in basis weight of 4% or less, as compared to the polyolefin porous substrate. A method for manufacturing the polyolefin separator and a secondary battery including the polyolefin separator are also disclosed.

Abstract: A separator substrate, a separator comprising the same, and an electrochemical device comprising the same are provided. The separator substrate comprises a crosslinked polyolefin resin and chromium (Cr) wherein the crosslinked polyolefin resin comprises a phosphorus-containing organic group grafted to a polyolefin chain, a gel fraction of the separator substrate is 3% to 80%, a standard deviation (?d) of thickness measured in at least 100 random points is 0.5 ?m or less, and a number of spots having a long side length of 50 ?m or more per m2 is 10 or less.