High Li ion conductivity in strontium doped Li7La3Zr2O12 garnet

Strontium doped lithium ion garnets Li 7 La 3 Zr 2 O 12 (LLZ) with 0.9   wt% to 8.4   wt% content of added Sr were synthesized via conventional solid-state reaction. X-ray diffraction patterns confirmed the cubic garnet structure of the sintered samples. A small amount of strontium was substituted to lanthanum in LLZ lattice. Further analysis showed SrCO 3 acted as a sintering aid for cubic LLZ ceramics and significantly increased the grain size of the sintered pellets. A conductivity of 2.10   ×   10 −   4   S/cm at 297   K was obtained for the undoped LLZ. The total ionic conductivity reached a maximum of about 5   ×   10 −   4   S/cm at 297   K with an activation energy of about 0.31   eV for 1.7   wt% Sr added LLZ sintered for 20–24   h in alumina crucible.