Provided is a layered double hydroxide (LDH) separator including a porous substrate made of a polymeric material; and a hydroxide-ion conductive layered compound being a LDH and/or a LDH-like compound with which pores of the porous substrate are plugged. The LDH separator has a mean porosity of 0.03% to less than 1.0%.

A low cost, sandwich-structured thin film composite (TFC) anion exchange membrane for redox flow batteries, fuel cells, electrolysis, and other electrochemical reaction applications is described. The sandwich-structured TFC anion exchange membrane comprises a microporous substrate membrane, a first hydrophilic ionomeric polymer coating layer on the surface of the microporous substrate layer, a cross-linked protonated polyamine anion exchange polymer coating layer on top of the first hydrophilic ionomeric polymer coating layer, and a second hydrophilic ionomeric polymer protective layer on top of the cross-linked protonated polyamine anion exchange polymer coating layer. Methods of making the TFC anion exchange membrane comprises a microporous substrate membrane and redox flow battery system incorporating the TFC anion exchange membrane comprises a microporous substrate membrane are also described.

A separator for a rechargeable battery includes a porous substrate and a heat resistance layer on at least one surface of the porous substrate. The heat resistance layer includes an acryl-based copolymer, an alkali metal, and a filler. The acryl-based copolymer includes a unit derived from (meth)acrylate or (meth)acrylic acid, a cyano group-containing unit, and a sulfonate group-containing unit.

A heat-resistant separator for an electrochemical element in which the thickness of the separator is reduced while maintaining the balance between the short circuit resistance, resistance, electrolyte impregnation performance, and electrolyte retention performance of the separator. A separator for an electrochemical element includes beaten cellulose fibers, wherein the value obtained by dividing the average value for the distance between the center point of a cellulose stem fiber constituting part of the separator and the center point of another cellulose stem fiber nearest to said cellulose stem fiber by the thickness of the separator is 0.80 to 1.35.

A separator includes a substrate and a coating layer on at least one surface of the substrate, wherein the coating layer includes first organic particles and second organic particles, and an average particle diameter of the first organic particles is larger than an average particle diameter of the second organic particles. The first organic particles protrude or extend to a height of about 0.1 μm to about 0.5 μm from a dented portion of a surface of the coating layer, and are distributed on the surface of the coating layer in an area ratio of about 5% or greater to less than 30% with respect to a total surface area of the coating layer. The separator may have improved adhesion to electrodes, insulation characteristics, and air permeability, and a battery including the separator may have improved lifespan characteristics.

New and/or improved coatings for porous substrates, including battery separators or separator membranes, and/or coated porous substrates, including coated battery separators, and/or batteries or cells including such coatings or coated separators, and/or related methods including methods of manufacture and/or of use thereof are disclosed. Also, new or improved coatings for porous substrates, including battery separators, which comprise at least a polymeric binder and heat-resistant particles with or without additional additives, materials or components, and/or to new or improved coated porous substrates, including battery separators, where the coating comprises at least a polymeric binder and heat-resistant particles with or without additional additives, materials or components are disclosed. Further, new or improved coatings for porous substrates, including battery separators, and new and/or improved coated porous substrates, including battery separators, new or improved coatings for porous substrates, including battery separators, which comprise at least (i) a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a cross-linker, a low-temperature shutdown agent, an adhesion agent, and a thickener, and new and/or improved coated porous substrates, including battery separators, where the coating comprises at least (i) a polymeric binder, (ii) heat-resistant particles, and (iii) at least one component selected from the group consisting of a cross-linker, a low-temperature shutdown agent, an adhesion agent, a thickener, a friction-reducing agent, a high-temperature shutdown agent are disclosed.

A coating solution for lithium ion battery separators which comprises inorganic particles, an organic polymer binder and carboxymethyl cellulose having an etherification rate of 1.10 to 2.00 or a salt thereof, or a coating solution for lithium ion battery separators comprising inorganic particles containing magnesium hydroxide having a linseed oil absorption of 30 to 80 (g/100 g), and a separator having a coating layer formed from the coating solution on a substrate and high safety and low internal resistance.

A lithium ion battery separator substrate, a preparation method and application thereof are provided. The substrate comprises a support layer and a dense layer, wherein the support layer comprises superfine main fibers, thermoplastic bonded fibers and the nanofibers, and the dense layer comprises nanofibers. The substrate has excellent high-temperature resistance performance, the substrate still has certain strength after being processed at 300° C. for 1 h, and the heat shrinkage rate is less than 5.0%; the substrate has a uniform and compact double-layer structure without a pinhole. Therefore, the requirements concerning heat resistance, porosity and strength of the substrate are met.

A battery separator and a preparation method therefor are provided. The separator includes a lithium ion battery separator substrate and an inorganic coating, the lithium ion battery separator substrate consists of a support layer and a dense layer, and the inorganic coating is coated on the dense layer; the separator has excellent high-temperature resistance, and still has good strength retention and the heat shrinkage rate thereof is no more than 2% after treatment at 300° C. for 1 h, and thus ensures the stability and isolation of the rigid structure of the separator coating at high temperatures; the substrate has a uniform and compact double-layer structure, effectively controls phenomena such as pinholes and filler particles fall-off in a subsequent coating process, and meets the requirements of lithium ion battery separators with respect to heat resistance, porosity and strength, thus having excellent comprehensive performance.

Battery separators and methods of making such separators are provided. The separators can be used in various alkaline batteries such as a Zn/MnO.sub.2 battery or the like. An alkaline battery separator comprises a first layer of polyvinyl alcohol fibers, a second layer of cellulose or a cellulose derivative and a third layer comprising a water soluble polymer. The battery separator has reduced pore sizes to reduce clogging, while still maintaining desirable wet ionic resistance, basis weight and absorption performance.