Aluminum-doped lithium ion conductor based on a garnet structure

A method for producing an aluminum-doped lithium ion conductor, the method comprising:

• melting initial materials in a skull crucible to form a melt;
• and
• cooling the melt to form the conductor,
• wherein the conductor is based on a garnet structure and comprises an aluminum-doped lithium lanthanum zirconate (LLZO) co-doped on a lanthanum site with Y3+ and at least one other trivalent cation having an ionic radius that is smaller than that of La3+, with the exception of Al3+,
• wherein the conductor has a lithium content that is superstoichiometric in comparison to a stoichiometric garnet structure,
• wherein the conductor has 90.1% or more of cubic crystal modification and 9.9% or less of tetragonal crystal modification,
• wherein the conductor has a lattice constant of a <12.965 Å,
• wherein the conductor has the chemical formula:
• Li7−3x+y′+2y″−z′−2z″+uAlx3+La3−y−y′−y″My3+My′2+My″1+Zr2−z−z′−z″Mz4+Mz′5+Mz6+O12±δ (I)
• in which:
• M3+ includes Y3+ and the at least one other trivalent cation having an ionic radius smaller than La3+, with the exception of Al3+,
• M2+ represents one or more divalent cations,
• M1+ represents one or more monovalent cations, with the exception of Li+,
• M4+ represents one or more tetravalent cations, with the exception of Zr4+,
• M5+ represents one or more pentavalent cations,
• M6+ represents one or more hexavalent cations,
• 0.1≤x<1,
• 0<y<2,
• 0≤y′<0.2,
• 0≤y″<0.2,
• 0≤y′+y″<0.2,
• 0≤z<0.5,
• 0≤z′<0.8,
• 0≤z″<0.5,
• 0≤δ<2, and
• wherein u>0.01 for a superstoichiometric lithium content.