Al-doped Li7La3Zr2O12 synthesized by a polymerized complex method

► We report Al doping effects on Li7La3Zr2O12 made by a polymerized complex method. ► Al doping can stabilize the cubic form Li7La3Zr2O12 relative to its tetragonal form. ► Al addition leads to a liquid phase which enhances densification during sintering. Sintering time is greatly shortened to 6 h at 1200 °C. ► 1.2 wt.% Al doped Li7La3Zr2O12 has 2 × 10−4 S cm−1 conductivity at room temperature.