POLYETHYLENE POROUS SEPARATOR FOR LITHIUM ION SECONDARY BATTERY HAVING HIGH POROSITY AND EXCELLENT MECHANIC AND HEAT PROPERTY AND PREPARATION METHOD THEREOF

摘要

PURPOSE: A polyethylene porous separator for a lithium ion secondary battery is provided to ensure high porosity, excellent mechanical properties, and low heat shrinkage rate, thereby enabling use for a lithium secondary battery with high cell efficiency. CONSTITUTION: A polyethylene porous separator for a lithium ion secondary battery comprises the steps of: melting and extruding 10~30 weight% of vegetable oil as a pore-forming agent and 60~80 weight% of high density polyethylene; heating the manufactured film; orienting the manufactured film and extracting the pore-forming agent; washing, drying and heat-fixing the oriented film; and irradiating radiation to the manufactured film.