The present application relates to a separator, comprising a substrate and a coating formed on at least one surface of the substrate, wherein the coating comprises inorganic particles and first organic particles embedded in the inorganic particles and forming protrusions on the surface of the coating, and the first organic particles have a primary particle morphology and a number-average particle size of ≥2 μm. The present application also relates to a secondary battery comprising the separator, a device comprising the secondary battery and a method for preparing the separator.

Articles and methods including composite layers for protection of electrodes in electrochemical cells are provided. In some embodiments, the composite layers comprise a polymeric material and a plurality of particles.

Articles and methods including composite layers for protection of electrodes in electrochemical cells are provided. In some embodiments, the composite layers comprise a polymeric material and a plurality of particles.

Provided is a separator for a power storage device that combines high permeability and battery safety at high temperature. The separator for a power storage device has an inorganic content layer that contains inorganic particles and polyolefin resin. In a cross section of the inorganic content layer, a ratio b of the area occupied by the inorganic particles is 9-35% [inclusive], the ratio of the area occupied by vacancies is 20-60% [inclusive], and a TD direction heat shrinkage a at 150° C. of the separator for a power storage device is 4% or less.

Provided is a separator for a power storage device that combines high permeability and battery safety at high temperature. The separator for a power storage device has an inorganic content layer that contains inorganic particles and polyolefin resin. In a cross section of the inorganic content layer, a ratio b of the area occupied by the inorganic particles is 9-35% [inclusive], the ratio of the area occupied by vacancies is 20-60% [inclusive], and a TD direction heat shrinkage a at 150° C. of the separator for a power storage device is 4% or less.

A separator for a lithium secondary battery and a method for manufacturing the same. Particularly, the separator is obtained through immersed phase separation, the content of inorganic particles is controlled to a predetermined level, and a fluorine-based binder polymer is used in combination with a polyvinyl acetate polymer, and thus shows improved heat shrinkage and enhanced adhesion to an electrode.

Provided is a separator having excellent safety and a lithium secondary battery including the same. The separator includes: a porous polymer substrate; and an organic/inorganic composite porous layer disposed on at least one surface of the porous polymer substrate and including inorganic particles and a binder polymer, wherein the inorganic particles have a BET specific surface area of 50-150 m.sup.2/g, the organic/inorganic composite porous layer has a thickness larger than the thickness of the porous polymer substrate, and the surface of the organic/inorganic composite porous layer has an arithmetic mean roughness of 100-500 nm.

An electrode sheet and a secondary battery comprising the same are provided. The electrode sheet comprises a current collector and an active material layer provided on at least one surface of the current collector. A first inorganic separation layer and a second inorganic separation layer are sequentially formed on the active material layer. The first inorganic separation layer comprises a plurality of pores having a diameter of 300 nm to 600 nm, and each of the plurality of pores extends from the first inorganic separation layer toward the second inorganic separation layer and penetrates through the second inorganic separation layer. The pore diameter of the pores in the second inorganic separation layer is uniform.

An electrode sheet and a secondary battery comprising the same are provided. The electrode sheet comprises a current collector and an active material layer provided on at least one surface of the current collector. A first inorganic separation layer and a second inorganic separation layer are sequentially formed on the active material layer. The first inorganic separation layer comprises a plurality of pores having a diameter of 300 nm to 600 nm, and each of the plurality of pores extends from the first inorganic separation layer toward the second inorganic separation layer and penetrates through the second inorganic separation layer. The pore diameter of the pores in the second inorganic separation layer is uniform.

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).