Separators, high performance electrochemical devices, such as, batteries and capacitors, including the aforementioned separators, systems and methods for fabricating the same. In one implementation, a separator is provided. The separator comprises a polymer substrate (131), capable of conducting ions, having a first surface and a second surface opposing the first surface. The separator further comprises a first ceramic-containing layer (136), capable of conducting ions, formed on the first surface. The first ceramic-containing layer (136) has a thickness in arrange from about 1,000 nanometers to about 5000 nanometers. The separator further comprises a second ceramic-containing layer (138), capable of conducting ions, formed on the second surface. The second ceramic-containing layer (138) is a binder-free ceramic-containing layer and has a thickness in arrange from about 1 nanometer to about 1,000 nanometers.

An embodiment is directed to a separator with a ceramic-comprising separator layer. The ceramic-comprising separator layer comprises porous metal oxide fibers with diameters in the range from around 3 nm to around 2 microns, aspect ratios in the range from around 20 to around 100,000, and a total open pore volume among the porous metal oxide fibers in the range from around 0.01 cm.sup.3/g to around 1 cm.sup.3/g.

A method for producing an electrolytic capacitor includes: preparing an anode foil, a cathode foil, and a fibrous structure, the anode foil having a porous portion including a dielectric layer; preparing a conductive polymer-containing liquid, the conductive polymer-containing liquid containing a conductive polymer component and a first solvent;

forming a separator by removing at least a part of the first solvent after applying the conductive polymer-containing liquid to the fibrous structure; forming a capacitor element from the anode foil, the separator, and the cathode foil; and impregnating the capacitor element with an electrolytic solution. An electrical conductivity of the electrolytic solution at 30° C. is 3.0 mS/cm or more.

A separator is provided which includes: a separator base including a porous polymer substrate having a plurality of pores, and a porous coating layer positioned on at least one surface of the porous polymer substrate and containing a plurality of inorganic particles and a binder polymer positioned on the whole or a part of the surface of the inorganic particles to connect the inorganic particles with one another and fix them; and a porous adhesive layer positioned on at least one surface of the separator base and including polyvinylidene fluoride-co-hexafluoropropylene containing vinylidene fluoride-derived repeating units and hexafluoropropylene-derived repeating units, wherein the ratio of the number of the hexafluoropropylene (HFP)-derived repeating units (HFP substitution ratio) based on the total number of the vinylidene fluoride-derived repeating units and the hexafluoropropylene-derived repeating units is 4.5% to 9%. An electrochemical device including the separator is also provided.

A separator for an electrochemical device including a porous separator substrate including a polymer material, and a porous coating layer coated on at least one surface of the porous separator substrate. The porous coating layer includes inorganic particles and a binder resin. The binder resin includes a mixture of polyvinyl acetate (PVAc) with an acrylic binder resin. The separator has improved wettability with an electrolyte by virtue of relatively high polarity of PVAc. In addition, it is possible to improve the peel force between the separator substrate and the porous coating layer by introducing PVAc and to reduce the thickness of the porous coating layer. Therefore, when introducing the separator to a battery, it is possible to improve the resistance characteristics, and to inhibit the porous coating layer from being spaced apart from the separator substrate or to inhibit the inorganic particles from being detached from the porous coating layer.

A cathode subassembly for use in an electrolytic capacitor may include a first separator sheet including a surface having first and second regions, where the second region extends from a perimeter of the first region to a first peripheral edge of the first sheet, a second peripheral edge of a second sheet is substantially aligned with the first peripheral edge, a conductive foil is sandwiched between the first and second sheets and disposed within the first region, the first and second sheets are adhered to each other in a sealing region extending from the second region to a region of a surface of the second sheet facing the second region, and the first sheet includes at least one first recess portion at the first peripheral edge aligned with at least one second recess portion at the second peripheral edge of the second sheet.

A cathode subassembly for use in an electrolytic capacitor may include a first separator sheet including a surface having first and second regions, where the second region extends from a perimeter of the first region to a first peripheral edge of the first sheet, a second peripheral edge of a second sheet is substantially aligned with the first peripheral edge, a conductive foil is sandwiched between the first and second sheets and disposed within the first region, the first and second sheets are adhered to each other in a sealing region extending from the second region to a region of a surface of the second sheet facing the second region, and the first sheet includes at least one first recess portion at the first peripheral edge aligned with at least one second recess portion at the second peripheral edge of the second sheet.

A separator for an electrochemical device including a porous polymer substrate; and a porous coating layer formed on at least one surface of the porous polymer substrate, wherein the porous coating layer comprises inorganic particles and a binder polymer positioned on at least a part of a surface of individual inorganic particles to connect and fix the inorganic particles with one another. The binder polymer comprises a first block having repeating units and a second block having repeating units. A method for manufacturing the same is also provided. The separator shows low resistance, improved adhesion to an electrode and improved swelling property with a solvent.

A battery separator includes: a polyolefin porous film; and a heat-resistant porous layer provided on at least one surface of the polyolefin porous film. The heat-resistant porous layer contains barium sulfate particles and an organic synthetic resin component. The barium sulfate particles are contained in the heat-resistant porous layer in an amount of 70 volume % or more and 96 volume % or less, and are contained in the heat-resistant porous layer in an amount of 1.8 g/m.sup.2 or more and 19.8 g/m.sup.2 or less. An amount of increase in an air permeability resistance per 1 μm thickness of the heat-resistant porous layer is 10.0 sec/100 ccAir or less, a shrinkage rate when the heat-resistant porous layer has been left under an atmosphere of 130° C. for 1 hour is 8.0% or less, and a concentration of hydrogen sulfide is 0.3 ppm by volume or less.

A capacitor 1 includes a capacitor element 3 holding solution between an anode foil 5 and a cathode foil 7 that are wound up with a separator 6 in between, a body case 2 for housing the capacitor element 3, and a sealing member 4 for sealing the body case 2. A part of the separator 6 makes contact, at a plurality of points or over an area, with the face of the sealing member 4 facing the capacitor element 3 so as to rest on that face. The solution contains, dissolved in a lipophilic solvent, deterioration preventing agent that solidifies by oxidation. The solution is supplied through the separator 6 to the sealing member 4 and permeates the sealing member 4, so that a coating 17 resulting from the agent solidifying coats the outer face of the sealing member 4, leaving the solution present in the sealing member 4.