CERAMIC-COATED SEPARATOR WITH LOW INTERNAL RESISTANCE, PREPARATION METHOD THEREFOR, AND LITHIUM-ION BATTERY

The present disclosure provides a low-internal-resistance ceramic-coated separator, a preparation method thereof, and a lithium battery. The low-internal-resistance ceramic-coated separator of the present disclosure includes a polymer base film, and a ceramic layer coated on one or two sides of the polymer base film. The ceramic layer adopts low-sodium boehmite and does not contain sodium carboxymethyl cellulose (CMC). A sodium content of the ceramic layer is less than 1000 ppm, so that a Gurley increase value of the separator is significantly lowered. When applied to the lithium battery, the ceramic layer can greatly reduce an internal resistance of a cell, thereby improving the power performance and discharge efficiency of the battery.