Effects of fabrication atmosphere conditions on the physico-chemical properties of garnet electrolyte

The effects of atmosphere conditions on physico-chemical properties of garnet type Ta-doped Li 7 La 3 Zr 2 O 12 (LLZT) fabricated by high-temperature sintering were investigated through experimental and theoretical analysis. Results revealed that the LLZT pellet fabricated in air atmosphere (LLZT-air) condition possessed higher mechanical properties than that in Ar condition (LLZT-Ar). Moreover, enhanced Li-ion conductivity and decreased electronic conductivity were also observed in LLZT-air, while impurity phase was observed in comparative case studies. This phenomenon can be ascribed to influence of oxygen vacancies (OVs) emerged during the Ar fabrication process. Specifically, symmetric Li/Li cell of LLZT-air exhibits a much higher critical current density (CCD) up to 0.55 mA cm −2 at 60 °C as well as a stable cycling at 0.3 mA cm −2 for over 500 h without Li dendrite penetration. The assembled solid-state LiCoO 2 /LLZT-air/Li cell possesses high initial capacity of 122.1 mAh g −1 .