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.

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.

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 method of preparing an electrochemical electrode which is partially or totally covered with a film that is obtained by spreading an aqueous solution comprising a water-soluble binder over the electrode and subsequently drying same. The production cost of the electrodes thus obtained is reduced and the surface porosity thereof is associated with desirable resistance values.

A method of preparing an electrochemical electrode which is partially or totally covered with a film that is obtained by spreading an aqueous solution comprising a water-soluble binder over the electrode and subsequently drying same. The production cost of the electrodes thus obtained is reduced and the surface porosity thereof is associated with desirable resistance values.