Abstract: Provided are a method of preparing carbon nanotube-olivine type lithium manganese phosphate composites and a lithium secondary battery using the same. The method includes acid-treating a carbon nanotube to purify the carbon nanotube by adding an acid solution to the carbon nanotube, forming a precursor mixture of the carbon nanotube and a metal precursor of olivine type lithium manganese phosphate, and heat-treating the precursor mixture. The carbon nanotube-olivine type lithium manganese phosphate composites can provide high energy density per unit volume and can improve output characteristics.

Abstract: Provided are a positive active material including a spinel lithium manganese oxide surface-coated with one or more types of nanoparticles selected from olivine-type lithium metal phosphate and metal oxide, a method of preparing the same and a lithium secondary battery using the same. The positive active material provides a lithium secondary battery having improved high-temperature cycle life characteristic and capacity per weight.