| abstract |
Disclosed are a multi-layer composite porous film and a manufacturing method thereof. More particularly, a manufacturing method, which includes filling pores on at least one face of a polyolefin microporous film substrate using a solvent, and then, applying a coating solution that contains a polymer binder or the polymer binder and inorganic particles, to the film to form a porous coating layer, as well as the multi-layer composite porous film manufactured by the same, are disclosed. The method for manufacturing the multi-layer composite porous film according to the disclosure may provide a multi-layer composite porous film having excellent permeability and shutdown function, without clogging the pores, by improving a coating process. Moreover, if applying the foregoing porous film as a separator to a battery, the battery having superior performance and high safety may be manufactured. |