Effect of Ca doping on Li ion conductivity of Ge and Ta doped garnet LLZO

• Published in: The Journal of physics and chemistry of solids Vol. 190; p. 111980
• Main Authors: Aote, Muktai, Deshpande, A.V.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-07-2024
• Subjects: Ceramics (A); Ionic conductivity (D); Li7La3Zr2O12 (A); Solid electrolyte (A); Ceramics (A); Ionic conductivity (D); Li7La3Zr2O12 (A); Solid electrolyte (A)
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2024.111980

The series Li6.55+xGe0.05La3-xCaxZr1.75Ta0.25O12 (x = 0, 0.05, 0.10, 0.15, 0.20) was prepared by conventional solid state reaction method with the sintering temperature of 1050 °C for 7.30 h by substituting Ca at the La site to increase the Li ion conductivity. The synergistic effects of Ca incorporation on Li6.55Ge0.05La3Zr1.75Ta0.25O12 were studied using various structural and electrochemical analyses. X-ray diffraction, scanning electron microscopy, and Impedance analysis were used to determine the crystal structure, morphology, and AC conductivity of the prepared ceramic samples, respectively. The highest conductivity of 9.95 x 10−4 S/cm was obtained for a 0.05 Ca ceramic sample with minimum activation energy of 0.23 eV. The DC polarization measurements confirmed the dominance of ionic conduction in 0.05 Ca ceramic. The results obtained make the 0.05 Ca ceramic sample a promising candidate as solid electrolytes for all solid state Li-ion batteries (ASSLIBs).
•Series Li6.55+xGe0.05La3-xCaxZr1.75Ta0.25O12 was prepared by SSR method at lower sintering temperature of 1050 °C for 7.30 h.•The Highest relative density of 95.09% was obtained for 0.05 Ca ceramic sample.•Highest RT ionic conductivity of 9.95 x 10−4 S/cm was achieved by 0.05 Ca ceramic with minimum activation energy of 0.23 eV.•The 0.05 Ca ceramic sample dominantly favours ionic conductivity.