Effect of Na substitution for La on Li ion conductivity of Li5La3Nb2O12 garnets by sol–gel process

Journal Article · Thu Mar 15 04:00:00 EDT 2018 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2017.11.047· OSTI ID:22805476

Peng, Hongjian; Li, Ling; Feng, Liuliu; Zhang, Yunqiang; Zou, Yingping ^[1]

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1. College of Chemistry and Chemical Engineering, Central South University, Changsha Hunan, 410083 (China)

Highlights: • The effect of Na substitution for La on Li ion conductivity in the Li5La3Nb2O12 solid state electrolyte is reported. • The power XRD patterns reveal that the partial substitutions of Na for La in Li{sub 5+2x}La{sub 3-x}Na{sub x}Nb{sub 2}O{sub 12} electrolytes are isostructural. • The new solid state electrolyte is very stable in potential range of −0.8 to 5.0V vs. Li/Li+. - Abstract: In this paper, the effect of Na substitution for La on Li ion conductivity in the well-known Li{sub 5}La{sub 3}Nb{sub 2}O{sub 12} parents with the cubic garnet framework prepared by sol-gel process is reported. The optimum condition is at 750 °C for 6 h in air with 10% excess lithium salt. The power XRD patterns reveal that the partial substitutions of Na for La in Li5 + 2{sub x}La{sub 3-x}Na{sub x}Nb{sub 2}O{sub 12} electrolytes are isostructural. The cubic lattice parameters decrease as the molar fractions of Na increasing. Among the Li5 + 2{sub x}La{sub 3-x}Na{sub x}Nb{sub 2}O{sub 12} compounds investigated, the Na-substituted Li{sub 6.4}La{sub 2.3}Na{sub 0.7}Nb{sub 2}O{sub 12} exhibits the highest ionic conductivity of 1.6 × 10{sup −4} S cm{sup -1} at room temperature with an activation energy of 0.41 eV. The new solid state electrolyte is very stable in potential range of −0.8 to 5.0 V vs. Li/Li{sup +}, and is also chemically stable against LiMn{sub 2}O{sub 4} and LiCoO{sub 2} compounds up to 900 °C, indicating that Li{sub 6.4}La{sub 2.3}Na{sub 0.7}Nb{sub 2}O{sub 12} is a promising solid state electrolyte for all-solid-state battery application.

• OSTI ID: 22805476
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Vol. 99; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CUBIC LATTICES
ELECTROLYTES
GARNETS
IONIC CONDUCTIVITY
LANTHANUM COMPOUNDS
LATTICE PARAMETERS
LITHIUM COMPOUNDS
LITHIUM IONS
NIOBATES
SOL-GEL PROCESS
SOLIDS
TEMPERATURE RANGE 0273-0400 K
X-RAY DIFFRACTION