Lithium stoichiometry of solid electrolytes based on tetragonal Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12}

Journal Article · Thu May 01 04:00:00 EDT 2014 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2014.01.041· OSTI ID:22348629

Il’ina, E. A. ^[1]; Shevelin, P. Y. ^[1]; Voronin, V. I.; Berger, I. F. ^[2]; Zhyravlev, N. A. ^[3]

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1. Institute of High-Temperature Electrochemistry, Ural Branch of RAS, Ekaterinburg (Russian Federation)
2. Institute of Metal Physics, Ural Branch of RAS, Ekaterinburg (Russian Federation)
3. Institute of Solid State Chemistry, Ural Branch of RAS, Ekaterinburg (Russian Federation)

Graphical abstract: - Highlights: • We prepared Li{sub x}La{sub 3}Zr{sub 2}O{sub 8.5+0.5x} (x = 6, 7, 8, 9, 10) by the citrate–nitrate method. • We studied phase composition and conductivity of Li{sub x}La{sub 3}Zr{sub 2}O{sub 8.5+0.5x}. • We proposed a simple method to determine the carbonate impurity content in the solid electrolytes. • The synthesized solid electrolytes Li{sub x}La{sub 3}Zr{sub 2}O{sub 8.5+0.5x} (x = 7–9) have 1.32–3.49 wt.% Li{sub 2}CO{sub 3}. • The composition with x = 9 has high total conductivity, 7.5 × 10{sup −6} S cm{sup −1}, at room temperature. - Abstract: Samples of Li{sub x}La{sub 3}Zr{sub 2}O{sub 8.5+0.5x} (x = 6, 7, 8, 9, 10) were synthesized with the citrate–nitrate method. Neutron diffraction studies have shown the presence of lithium carbonate impurities in the synthesized compounds. We propose a simple and effective method to determine the carbonate impurity content in the solid electrolytes. The technique is based on the measurement of the carbon dioxide volume produced from the interaction of the investigated material with acid. Determined in this way, the content of Li{sub 2}CO{sub 3} in the synthesized electrolytes Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12}, Li{sub 8}La{sub 3}Zr{sub 2}O{sub 12.5} and Li{sub 9}La{sub 3}Zr{sub 2}O{sub 13} are 1.32 ± 0.04, 1.95 ± 0.06 and 3.49 ± 0.10 wt.%, respectively. From the obtained data, the actual lithium content per formula unit of complex oxide was calculated for the synthesized compounds. The composition with x = 9 had the highest total conductivity, σ = 7.5 × 10{sup −6} S cm{sup −1}, at room temperature. All the investigated electrolytes have an activation energy of approximately 50 kJ mol{sup −1}.

• OSTI ID: 22348629
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Vol. 53; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
CARBON DIOXIDE
CERAMICS
CITRATES
IMPURITIES
INTERACTIONS
IONIC CONDUCTIVITY
LITHIUM
LITHIUM CARBONATES
NEUTRON DIFFRACTION
NITRATES
SOL-GEL PROCESS
SOLID ELECTROLYTES
SPECTROSCOPY