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 organic particles, the organic particles comprise first organic particles and second organic particles; the first organic particles and the second organic particles are embedded in the inorganic particles and form protrusions on the surface of the coating; the first organic particles have a number-average particle size of >10 μm, and the second organic particles have a number-average particle size of 2 μm-10 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.

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 organic particles, the organic particles comprise first organic particles and second organic particles; the first organic particles and the second organic particles are embedded in the inorganic particles and form protrusions on the surface of the coating; the first organic particles have a number-average particle size of >10 μm, and the second organic particles have a number-average particle size of 2 μm-10 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.

The present application relates to a separator in the electrochemical field and a preparation method therefor, and to a secondary battery comprising the separator, a device comprising the secondary battery. The separator of the present application is prepared by a simple process and has excellent heat resistance performance. Moreover, the secondary batteries and devices comprising the separator of the present application have good safety performance and cycling performance.

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.

There is provided a negative electrode (100) for a lithium ion secondary battery, in which a negative electrode active material layer (120) containing at least a negative electrode active material and a binder is formed on a current collector (110). An insulating layer (300) containing at least an insulating material and a binder is further provided on a surface of the negative electrode active material layer (120), the binder contained in the insulating layer (300) includes at least styrene-butadiene rubber and at least one selected from carboxymethyl cellulose and salts thereof, and the binder contained in the negative electrode active material layer (120) is at least one selected from polyacrylic acid and salts thereof.

There is provided a negative electrode (100) for a lithium ion secondary battery, in which a negative electrode active material layer (120) containing at least a negative electrode active material and a binder is formed on a current collector (110). An insulating layer (300) containing at least an insulating material and a binder is further provided on a surface of the negative electrode active material layer (120), the binder contained in the insulating layer (300) includes at least styrene-butadiene rubber and at least one selected from carboxymethyl cellulose and salts thereof, and the binder contained in the negative electrode active material layer (120) is at least one selected from polyacrylic acid and salts thereof.

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.

A separator for a non-aqueous secondary battery contains: a porous substrate and a heat-resistant porous layer that is provided on one side or on both sides of the porous substrate, and that contains a resin and inorganic particles, in which (A) the resin contains a copolymer having a vinylidene fluoride unit and a hexafluoropropylene unit satisfying particular requirements, a content of the inorganic particles in the heat-resistant porous layer is from 50% by mass to 90% by mass, and the inorganic particles contain first inorganic particles and second inorganic particles satisfying particular size requirements, or (B) a content of the inorganic particles in the heat-resistant porous layer is from 50% by mass to 90% by mass, and the inorganic particles contain first inorganic particles that are metal sulfate (or metal hydroxide) particles and second inorganic particles that are inorganic particles other than metal sulfate (or metal hydroxide) particles.

In a non-aqueous electrolyte secondary battery according to one exemplary embodiment, a separator includes a substrate, a first filler layer containing phosphate particles and formed on at least one surface of the substrate, and a second filler layer containing inorganic particles and formed on a surface of the first filler layer on the side of the at least one surface of the substrate. The phosphate particles have a BET specific surface area of 5 m.sup.2/g or more and 100 m.sup.2/g or less.