The present disclosure provides a method of preparing a separator for a lithium secondary battery, comprising: (S1) bringing polymer particles into electric charging to obtain electrically charged polymer particles; (S2) transferring the electrically charged polymer particles on at least one surface of a porous polymer substrate to form an electrode-adhesion layer whose area ranges from 1 to 30% based on the total area of the porous polymer substrate; and (S3) fixing the electrode-adhesion layer with heat and pressure.
In accordance with the present disclosure, in the preparation of a separator for a lithium secondary battery, an electrode-adhesion layer is applied by using electrostatic charging, more specifically coating polymer particles by way of laser printing, without the addition of a slurry in a solvent, thereby allowing easy handling and storage and needs no drying step of the solvent to provide cost savings effect as well as rapid and efficient preparation of the separator. Further, the electrode-adhesion layer is applied in a certain area, not the whole area in the separator, thereby preventing an excessive resistance rise in a lithium secondary battery using the separator.