Abstract: A polymer battery separator with an interpenetrating network structure and a preparation method thereof are disclosed. A multilayer microporous separator includes a PVDF layer, and a PE-PVDF porous substrate located on a surface of the PVDF layer. Finger-like through holes with a pore size of 100-150 nm are distributed in the PVDF finger-like pore layer. An interpenetrating network structure with a pore size of 50-100 nm is distributed on an interface between the PVDF finger-like pore layer and the PE microporous layer. Micropores with a pore size of 20-50 nm are distributed in the PE microporous layer. The surface of the PVDF layer is covered with the PE-PVDF porous substrate, so that the multilayer microporous separator forms an interpenetrating network structure, which has improved thermal stability and high-temperature resistance.

Abstract: A coating slurry with high adhesion and high ionic conductivity, a preparation method thereof, and a lithium battery separator are provided. The coating slurry with the high adhesion and the high ionic conductivity includes: PEAE: 1 to 60 parts; a dispersing agent: 0.01 to 10 parts; a wetting agent: 0.01 to 15 parts; and a solvent: 100 parts. The PEAE can be evenly coated on a basal membrane to form a lithium battery separator, which solves the problem that pure PEAE cannot be directly and evenly coated on a separator. The PEAE is coated on the basal membrane for the first time to prepare the lithium battery separator, which ensures that the lithium battery separator has characteristics of the high adhesion and the high ionic conductivity.

Abstract: A coating slurry with high adhesion and high ionic conductivity, a preparation method thereof, and a lithium battery separator are provided. The coating slurry with the high adhesion and the high ionic conductivity includes: PEAE: 1 to 60 parts; a dispersing agent: 0.01 to 10 parts; a wetting agent: 0.01 to 15 parts; and a solvent: 100 parts. The PEAE can be evenly coated on a basal membrane to form a lithium battery separator, which solves the problem that pure PEAE cannot be directly and evenly coated on a separator. The PEAE is coated on the basal membrane for the first time to prepare the lithium battery separator, which ensures that the lithium battery separator has characteristics of the high adhesion and the high ionic conductivity.

Abstract: A polymer battery separator with an interpenetrating network structure and a preparation method thereof are disclosed. A multilayer microporous separator includes a PVDF layer, and a PE-PVDF porous substrate located on a surface of the PVDF layer. Finger-like through holes with a pore size of 100-150 nm are distributed in the PVDF finger-like pore layer. An interpenetrating network structure with a pore size of 50-100 nm is distributed on an interface between the PVDF finger-like pore layer and the PE microporous layer. Micropores with a pore size of 20-50 nm are distributed in the PE microporous layer. The surface of the PVDF layer is covered with the PE-PVDF porous substrate, so that the multilayer microporous separator forms an interpenetrating network structure, which has improved thermal stability and high-temperature resistance.

Abstract: A cast piece cooling method, a gel sheet, a multilayer microporous polyethylene separator, and a preparation method are provided. The cast piece cooling method includes: changing an opening degree of a die head so that a molten material flowing out of the die head is an arc-shaped molten material; calendering a cast piece so that the arc-shaped molten material passes vertically through a gap between a first casting roller and a pinch roller to form a calendered cast piece; and gradually cooling, so that the calendered cast piece is guided and transported along surfaces of other casting rollers to the last casting roller, and cooling the calendered cast piece, to obtain a gel sheet.

Abstract: A polyolefin porous separator includes a first surface and a second surface corresponding to the first surface. The surfaces of the polyolefin porous separator contain dendritic crystals and micropores, the dendritic crystals intersect with the micropores on the first surface or/and the second surface, and the dendritic crystals penetrate through the second surface from the first surface. A preparation method of the polyolefin porous separator includes: (1) a mixed melting of polyethylene resin and a mineral oil; (2) an extrusion of the mineral oil/polyethylene resin molten mixture; (3) a stretching of a thick sheet in a machine direction (MD); (4) a stretching of the separator in a transverse direction (TD); (5) immersing the separator into a solvent to extract the mineral oil; (6) a secondary stretching of the separator in the TD; and (7) subjecting the separator having the longitudinal crystals to a heat-setting treatment and then rolling up.

Abstract: A method for measuring the oil content of a lithium battery separator by using DSC includes the following steps: taking 5-10 mg of an oil-containing separator sample from the lithium battery separator, and taking 5-10 mg of an oil-free separator sample from an oil-free separator; performing an enthalpy test on the oil-free separator sample at room temperature by using a differential scanning calorimeter to obtain a first enthalpy value, and performing an enthalpy test on the oil-containing separator sample by using the differential scanning calorimeter to obtain a second enthalpy value; subtracting the second enthalpy value from the first enthalpy value to obtain a difference, and then dividing the difference by the first enthalpy value to obtain the oil content of the oil-containing separator sample.

Abstract: A polyolefin porous separator includes a first surface and a second surface corresponding to the first surface. The surfaces of the polyolefin porous separator contain dendritic crystals and micropores, the dendritic crystals intersect with the micropores on the first surface or/and the second surface, and the dendritic crystals penetrate through the second surface from the first surface. A preparation method of the polyolefin porous separator includes: (1) a mixed melting of polyethylene resin and a mineral oil; (2) an extrusion of the mineral oil/polyethylene resin molten mixture; (3) a stretching of a thick sheet in a machine direction (MD); (4) a stretching of the separator in a transverse direction (TD); (5) immersing the separator into a solvent to extract the mineral oil; (6) a secondary stretching of the separator in the TD; and (7) subjecting the separator having the longitudinal crystals to a heat-setting treatment and then rolling up.

Abstract: A method for measuring the oil content of a lithium battery separator by using DSC includes the following steps: taking 5-10 mg of an oil-containing separator sample from the lithium battery separator, and taking 5-10 mg of an oil-free separator sample from an oil-free separator; performing an enthalpy test on the oil-free separator sample at room temperature by using a differential scanning calorimeter to obtain a first enthalpy value, and performing an enthalpy test on the oil-containing separator sample by using the differential scanning calorimeter to obtain a second enthalpy value; subtracting the second enthalpy value from the first enthalpy value to obtain a difference, and then dividing the difference by the first enthalpy value to obtain the oil content of the oil-containing separator sample.