SEPARATOR HAVING BINDER LAYER, ELECTROCHEMICAL DEVICE COMPRISING THE SEPARATOR, AND METHOD OF PREPARING THE SEPARATOR

摘要

The present invention relates to a separation film having a binder layer, an electrochemical device including the separation film, and a manufacturing method of the separation film. An embodiment of the present invention provides the separation film which has a porous substrate, a porous coating layer, and the binder layer, wherein a binder which exists in the porous coating layer and the binder layer includes two or more kinds of Polyvinylidene Fluoride (PVDF) homopolymer or Polyvinylidene Fluoride-co-hexafluoropropylene (P(VDF-HFP)) copolymer which has 3 wt% or more of the content difference of Hexafluoropropylene (HFP). According to another embodiment of the present invention, the provided manufacturing method of the separation film includes a forming step of binder solution, a forming step of slurry, and a forming step of the porous coating layer, wherein a binder in the binder solution includes two or more kinds of PVDF homopolymer or P(VDF-HFP) copolymer which has 3 wt% or more of the content difference of HFP. The separation film which is manufactured according to the embodiment of the present invention additionally has the binder layer which is formed with the binder of high adhesive strength by the drying of the porous coating layer which includes the binder without separately arranging the forming step of the binder layer in a manufacturing process. The binder layer which is formed like the forementioned has excellent adhesive strength when being combined with an electrode and improves cycle characteristics by showing an effect of suppressing the increase of resistance on an interface of the electrode. [Reference numerals] (AA) Binder layer; (BB) Porous coating layer; (CC) Porous substrate