Separator including coating layer of organic and inorganic mixture containing polyimide, and battery including the same

Disclosed herein is a separator for batteries. The separator includes a coating layer containing polyimide and an organic binder. Specifically, a highly heat resistant polyimide capable of being easily dissolved in a low boiling point solvent and compatible with the organic binder is used as an organic binder component of the coating agent to be coated on a polyolefin base film, thereby improving heat resistance of the base film vulnerable to heat. In addition, the present disclosure provides an electrochemical battery, which includes the separator exhibiting excellent adhesion and has improved stability and lifespan.