POUCH-TYPE SECONDARY BATTERY

A pouch type secondary battery which comprises an electrode assembly; a battery case comprising an accommodation portion for accommodating the electrode assembly and a terrace portion formed along a perimeter of the accommodation portion; an electrode lead connected to the electrode assembly and protruding to the outside of the battery case via the terrace portion; a lead film disposed between the electrode lead and the battery case; and a gas guide film disposed between the electrode lead and the lead film, wherein the terrace portion comprises a sealing portion with a portion thereof sealed along the perimeter of the accommodation portion, and the lead film comprises inorganic particles is provided. The pouch type secondary battery includes inorganic particles in a gas permeable lead film, and may thus improve gas discharge performance.