Novel or improved microporous single or multilayer battery separator membranes, separators, batteries including such membranes or separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries are provided. In accordance with at least certain embodiments, a multilayer dry process polyethylene/polypropylene/polyethylene microporous separator which is manufactured using the inventive process which includes machine direction stretching followed by transverse direction stretching and a subsequent calendering step as a means to reduce the thickness of the multilayer microporous membrane, to reduce the percent porosity of the multilayer microporous membrane in a controlled manner and/or to improve transverse direction tensile strength. In a very particular embodiment, the inventive process produces a thin multilayer microporous membrane that is easily coated with polymeric-ceramic coatings, has excellent mechanical strength properties due to its polypropylene layer or layers and a thermal shutdown function due to its polyethylene layer or layers. The ratio of the thickness of the polypropylene and polyethylene layers in the inventive multilayer microporous membrane can be tailored to balance mechanical strength and thermal shutdown properties.

A one-step molded lithium ion battery separator and preparation method and application thereof are provided. The battery separator comprises a support layer and a filler layer. The support layer comprises at least two of superfine main fiber, thermoplastic bonded fiber and first nanofiber, and the filler layer comprises at least one of inorganic fillers and third nanofiber. The lithium ion battery separator has a thickness of 19-31 μm, a maximum pore diameter of no more than 1 μm, and a heat shrinkage rate of less than 3% after treatment at 300° C. for 1 hour, and the separator still has a certain strength at a high temperature, ensuring stability and isolation of the rigid structure of the filler layer at a high temperature, satisfying requirements of the separator in terms of heat resistance, pore size and strength, having excellent comprehensive performance.

A one-step molded lithium ion battery separator and preparation method and application thereof are provided. The battery separator comprises a support layer and a filler layer. The support layer comprises at least two of superfine main fiber, thermoplastic bonded fiber and first nanofiber, and the filler layer comprises at least one of inorganic fillers and third nanofiber. The lithium ion battery separator has a thickness of 19-31 μm, a maximum pore diameter of no more than 1 μm, and a heat shrinkage rate of less than 3% after treatment at 300° C. for 1 hour, and the separator still has a certain strength at a high temperature, ensuring stability and isolation of the rigid structure of the filler layer at a high temperature, satisfying requirements of the separator in terms of heat resistance, pore size and strength, having excellent comprehensive 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 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.

Disclosed herein are a multilayer separator for a lithium secondary battery capable of preventing an internal short-circuit due to growth of lithium dendrite, and a method of manufacturing the same.

Disclosed herein are a multilayer separator for a lithium secondary battery capable of preventing an internal short-circuit due to growth of lithium dendrite, and a method of manufacturing the same.

Disclosed herein is a battery separator comprising two porous or microporous layers and a heat-resistant layer between the two porous or microporous layers. The heat-resistant layer may be a ceramic layer or a layer containing a high melt integrity polymer. In some embodiments, the battery separator may further comprise one or more adhesive layers between the two porous or microporous layers. The resulting battery separator may be safer, have more integrity, and/or have shutdown function.

Disclosed herein is a battery separator comprising two porous or microporous layers and a heat-resistant layer between the two porous or microporous layers. The heat-resistant layer may be a ceramic layer or a layer containing a high melt integrity polymer. In some embodiments, the battery separator may further comprise one or more adhesive layers between the two porous or microporous layers. The resulting battery separator may be safer, have more integrity, and/or have shutdown function.

A multilayer porous membrane with two exterior layers and at least one interior layer. The average pore size of the interior layer is greater than that of either of the two exterior layers. The multilayer porous membrane may be used, for example, as or as part of a battery separator. Compared to prior multilayer porous membranes for battery separators, the multilayer porous membrane herein may exhibit at least one of improved thermal properties, improved anti-metal contamination properties, improved ease of manufacture, and combinations thereof.