The present invention relates to a separator for electrochemical elements, the separator comprising synthetic fibers and beaten cellulose fibers, wherein the beaten cellulose fibers have a Canadian standard freeness measured in accordance with JIS P 8121 of 50 ml or more and 500 ml or less, and in a fiber diameter distribution histogram of the beaten cellulose fibers, (1) the fibers have a maximum frequency peak in a range of 50 μm or less, and (2) a ratio of the fibers having a fiber diameter of 20 μm or less is 55% or more.

Provided are a separator for a lithium secondary battery including a substrate and a heat-resistance porous layer disposed on at least one surface of the substrate and including a cross-linked binder, wherein the cross-linked binder has a cross-linking structure of a compound represented by Chemical Formula 2, and a lithium secondary battery including the same.

A single-electrode battery subassembly includes a separator comprising an electrolyte. The separator has a first surface and an opposing second surface. A single electrode is disposed over the first surface of the separator. A removable, electrically inert substrate disposed on the second surface of the separator.

The present invention relates to a separator for a secondary battery which is capable of improving a shut-down function of a cellulose-based multilayer separator physically having high strength. The separator for a secondary battery comprises a substrate formed of cellulose-based nanofibers and polyethylene nanoparticles; and a resin layer stacked on one surface or both surfaces of the substrate, the resin being formed from a polyolefin.

Energy storage devices, battery cells, and batteries may include a battery cell component that is formed by a method that includes forming a slurry that includes a ceramic material, a binder, and an ionic dispersant. The ceramic material may be greater than 50% of the slurry by weight. The method may also include applying the slurry to a polymeric material to form a two-layer separator. The slurry may be applied to a thickness of less than or about 10 μm.

This separator for nonaqueous electrolyte secondary batteries contains a polymer compound and a solid electrolyte, and has a pore volume of 0.06 cm.sup.3/gor less.

A separator for a lithium-based battery, and method for fabricating the same is disclosed. The method includes oxidizing cellulose fibrils to form oxidized cellulose having carboxylic functional groups, decorating the oxidized cellulose with nanoparticles, and forming the nanoparticle-decorated oxidized cellulose into a film to become the separator for the lithium-based battery. The cellulose may be a bacterial cellulose. The cellulose fibrils may be oxidized through a TEMPO oxidation. Decorating the oxidized cellulose with nanoparticles may include introducing a precursor solution to the oxidized cellulose that reacts with hydroxyl groups of the oxidized cellulose while preserving the carboxylic functional groups, causing the nanoparticles to nucleate on the surface of the oxidized cellulose. The nanoparticles may be composed of an oxide material. The oxide material may be SiO.sub.2. The precursor solution may be tetraethyl orthosilicate (TEOS).

A thin separator for electrochemical elements, which has achieved chemical stability, while maintaining a good balance among short-circuit resistance, resistivity, electrolyte solution impregnability and electrolyte solution retainability of the separator. A separator for electrochemical elements, which is interposed between a pair of electrodes so as to separate the electrodes from each other, and which holds an electrolyte solution. This separator for electrochemical elements is composed of beaten cellulose fibers and thermoplastic synthetic fibers, and has a thickness of 5.0-30.0 μm and a density of 0.50-0.75 g/cm.sup.3; and the thickness X (μm) and the air resistance Y (second/100 ml) of this separator for electrochemical elements satisfy formula 1:
Y≥0.01X.sup.2−0.6X+11.5.

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%.

Disclosed is a method for producing polymer-encapsulated Li.sub.2S.sub.x (where 1≤x≤2) nanoparticles. The method comprises the step of forming a mixture of a polymer and sulfur. The method further comprises vulcanizing the mixture at a vulcanization temperature attained at a heating rate, in a vulcanization atmosphere, and electrochemically reducing a vulcanized product at a reduction potential. Also disclosed is a method for producing a battery component, the component comprising a cathode and a separator.