The present invention relates to a lithium secondary battery. More specifically, according to embodiments of the present invention the lithium battery, which includes a cathode, an anode, and a separate membrane inserted between the cathode and the anode, is characterized in that the separator membrane is a polyolefin porous membrane which has an aramid coating layer; and the cathode includes a lithium metal oxide cathode active material which has an olivine-type iron phosphate lithium coating layer, or the anode includes a carbon anode active material which has a spinel-type lithium titanium oxide coating layer. The lithium secondary battery in accordance with embodiments of the present invention has excellent basic electric performance and improved stability.