Solid ionic conductor, solid electrolyte including the same, lithium battery including said solid electrolyte, and method of manufacturing said lithium battery

A solid ion conductor including a garnet-type oxide represented by Formula 4 below, a solid electrolyte including the solid ion conductor, a lithium battery including the solid ion conductor, and a method of preparing the solid ion conductor Li 5+x+2y (D y ,La 3-y )Zr 2 O d wherein D is K, Rb, or Cs, 0 < x+2y ¤ 3, 0 < y ¤ 0.5 and 0 < d ¤ 12; and O is partially or totally substituted with at least one of a pentavalent anion, a hexavalent anion, and a heptavalent anion.