Distribution and mobility of lithium in NASICON-type Li1-xTi2-xNbx(PO4)3 (0 ≤ x ≤ 0.5) compounds

Journal Article · Tue May 15 00:00:00 EDT 2018 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2018.01.022· OSTI ID:22805123

Kahlaoui, Radhouene ^[1]; Arbi, Kamel ^[2]; Jimenez, Ricardo; Sobrados, Isabel; Sanz, Jesus ^[2]; Ternane, Riadh ^[1]

---

1. Laboratoire d’Application de la Chimie aux Ressources et Substances Naturelles et à l’Environnement (LACReSNE), Université de Carthage, Faculté des Sciences de Bizerte, 7021 Zarzouna, Bizerte (Tunisia)
2. Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciónes Científicas (CSIC), Cantoblanco, 28049 Madrid (Spain)

Highlights: • Li{sub 1-x}Ti{sub 2-x}Nb{sub x}(PO{sub 4}){sub 3} (0 ≤ x ≤ 0.5) were prepared via solid-state reaction. • The substitution of Ti{sup 4+} by Nb{sup 5+} in LiTi{sub 2}(PO{sub 4}){sub 3} increases unit cell dimensions. • The Rietveld analysis of XRD patterns was performed to deduce location of Li ions. • LiTi{sub 2}(PO{sub 4}){sub 3} have the highest total conductivity and low activation energy. - Abstract: The NASICON-type Li{sub 1-x}Ti{sub 2-x}Nb{sub x}(PO{sub 4}){sub 3} (0 ≤ x ≤ 0.5) has been prepared using a conventional solid-state reaction and characterized by powder X-ray (XRD), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR) and impedance spectroscopy (IS). The substitution of Ti{sup 4+} by Nb{sup 5+} in LiTi{sub 2}(PO{sub 4}){sub 3} increases unit cell parameters of NASICON phases (S.G. R 3-bar c). The parallel XRD and NMR analysis confirmed the formation of secondary phases besides NASICON compounds. The NMR components detected in {sup 93}Nb and {sup 31}P MAS-NMR spectra have been ascribed to formation of crystalline NbPO{sub 5} and NASICON phases. The substitution of Ti{sup 4+} by Nb{sup 5+} produces detection of three equally spaced {sup 31}P MAS-NMR P(OTi){sub 4-n}(ONb){sub n} components, whose intensity changes with the Nb content of the NASICON phase. On the other hand, the broad {sup 31}P NMR band detected at ∼−130 ppm has been ascribed to the formation of an amorphous Nb phosphate that strongly affects conductivity of samples. At 355 K, total conductivity decreased from 1.2 × 10{sup −7} S cm{sup −1} (Ea = 0.49 eV) to 6.0 × 10{sup −9} S cm{sup −1} (Ea = 0.56 eV) when going from LiTi{sub 2}(PO{sub 4}){sub 3} to Li{sub 0.5}Ti{sub 1.5}Nb{sub 0.5}(PO{sub 4}){sub 3}. This important decrease has been related to the increment of activation energy (stronger Li-network interaction); however, further studies are required to understand the deleterious effect of niobium in Li{sub 1-x}Ti{sub 2-x}Nb{sub x} (PO{sub 4}){sub 3} series.

• OSTI ID: 22805123
• Journal Information: Materials Research Bulletin, Vol. 101; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTIVATION ENERGY
ION MOBILITY
LATTICE PARAMETERS
LITHIUM COMPOUNDS
LITHIUM IONS
NIOBIUM
NIOBIUM 93
NIOBIUM COMPOUNDS
NIOBIUM IONS
NUCLEAR MAGNETIC RESONANCE
PHOSPHATES
PHOSPHORUS 31
SCANNING ELECTRON MICROSCOPY
SPECTROSCOPY
SUPERCONDUCTORS
TITANIUM COMPOUNDS
TITANIUM IONS
X-RAY DIFFRACTION