POSITIVE ACTIVE MATERIAL, AND SECONDARY BATTERY COMPRISING THE SAME

摘要

Provided is a positive active material. The positive active material may comprise a first element formed of a plurality of metals including a first metal and a second element formed of one or more first elements. The second element may comprise: a center portion; a surface portion; a seed region which is adjacent to the center portion and in which the first element whose first metal content varies is disposed; and a maintenance region which is adjacent to the surface portion and in which the first element whose first metal content is constant is disposed. The length of the seed region in a direction from the center portion to the surface portion is greater than 1 μm.