CATHODE MATERIAL IMPROVED CONDUCTIVITY, CATHODE AND ELECTROCHEMICAL DEVICE INCLUDING THE SAME

摘要

The present invention relates to a cathode mixture with improved conductivity, a cathode and an electrochemical device comprising the same and, more specifically, to a cathode mixture comprising: a lithium manganese oxide having a core-shell structure by phase transition of a crystal structure from a cubic structure to a tetragonal structure in the direction of the center of a particle from the surface thereof in a discharge process into 2.5 or 3.5 V, as a cathode mixture comprising a lithium manganese oxide with a spinel structure; a conductive material formed on the surface of a shell part of the tetragonal structure formed by the phase transition in the discharge process; a polymer binder; and a conductive polymer, and a cathode and an electrochemical device comprising the cathode mixture. According to an embodiment of the present invention, in the lithium manganese oxide with the spinel structure, since the conductive polymer is located on the surface of the shell part with the tetragonal structure, the electrical conductivity is improved, thereby increasing participation in the reaction in 3 V area, and a conduction path is provided, thereby improving the capacity, life property and rate capacity of the electrochemical device.