Thermal behavior and lithium ion conductivity of L₂O-Al₂O₃-TiO₂-SiO₂-P₂O₅ glass-ceramics

Abstract

A lithium ion conductive solid electrolyte, L₂O-Al₂O₃-TiO₂-SiO₂-P₂O₅ glass with NASICONtype structure have been synthesized and transformed into glass-ceramic through thermal-treatment at various temperatures from 700 to 1 000 °C for 12 h. The differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and complex impedance techniques were employed to characterize the samples. The experimental results indicated that the capability of glass forming in this system is superior to that of L₂O-Al₂O₃-TiO₂-P₂O₅. The glass has an amorphous structure and resultant glass-ceramic mainly consisting of LiTi₂(PO₄)₃ phases. Impurity phases AlPO₄, TiO₂, TiP₂O₇ and unidentified phase were observed. With the enhanced heat-treatment temperature, grain grew gradually and lithium ion conductivity of glass-ceramics increased accordingly, the related impedance semicircles were depressed gradually and even disappeared, which could be analytically explained by the coordinate action of the ‘Constant phase element’ (CPE) model and the ‘Concept of Mismatch and Relaxation’ model (CMR). When the sample is devitrified at 1 000 °C, the maximum room temperature lithium ion conductivity comes up to 4.1×10⁻⁴ S/cm, which is suitable for the application as an electrolyte of all-solid-state lithium batteries.

Keywords

inorganic solid electrolyte / glass-ceramic / L₂O-Al₂O₃-TiO₂-SiO₂-P₂O₅ system / LiTi₂(PO₄)₃ phase

References

[1] Takada K., Ma R., Osada M., . Formation of Nano-sized Particles of a Solid Electrolyte by Laser Ablation [J]. Journal of Power Sources, 2005, 146(1–2): 703-706.

[2] Narváez-Semanate J. L., Rodrigues A. C. M. Microstructure and Ionic Conductivity of Li1+xAlxTi2-x(PO4)3 NASICON Glassceramics [J]. Solid State Ionics, 2010, 181(25–26): 1 197-1 204.

[3] Johnson P., Sammes N., Imanishi N., . Effect of Microstructure on the Conductivity of a NASICON-type Lithium Ion Conductor [J]. Solid State Ionics, 2010, 192(1): 326-329.

[4] Wen Z. Y., Xu X. X., Li J. X. Preparation, Microstructure and Electrical Properties of Li_1.4Al_0.4Ti_1.6(PO₄)₃ Nanoceramics [J]. J. Electroceram., 2009, 22(1–3): 342-345.

[5] Fu J. Superionic Conductivity of Glass-ceramics in the System Li₂OAl₂O₃-TiO₂-P₂O₅ [J]. Solid State Ionics, 1997, 96(3–4): 195-200.

[6] Thokchom J. S., Kumar B. Microstructural Effects on the Superionic Conductivity of a Lithiated Glass-ceramic [J]. Solid State Ionics, 2006, 177(7–8): 727-732.

[7] Aono H., Sugimoto E., Sadaoka Y., . Ionic Conductivity of Solid Electrolytes Based on Lithium Titanium Phosphate [J]. J. Electrochem. Soc., 1990, 137(4): 1 023-1 027.

[8] Alpen U. V. Li₃N: A Promising Li Ionic Conductor [J]. Journal of Solid State Chemistry, 1979, 29(3): 379-392.

[9] J Fu. Lithium Ion Conductive Glass-ceramics [P]. US Patent 5702995, 1997

[10] Fu J. Fast Li⁺ Ion Conduction in Li₂O-(Al₂O₃, Ga₂O₃)-TiO₂-P₂O₅ Glass-ceramics [J]. J. Mater. Sci., 1998, 33(6): 1 549-1 553.

[11] Cabral A. A., Cardoso A. A. D., Zanotto E. D. Glass-forming Ability Versus Stability of Silicate Glasses. I. Experimental Test [J]. Journal of Non-Crystalline Solids, 2003, 320(1–3): 1-8.

[12] Cruz A. M., Ferreira E. B., Rodrigues A. C. M. Controlled Crystallization and Ionic Conductivity of a Nanostructure LiAlGePO₄ Glass-ceramic [J]. J. Non-Cryst. Solids, 2009, 355(45–47): 2 295-2 301.

[13] Kosova N. V., Devyatkina E. T., Stepanov A. P., . Lithium Conductivity and Lithium Diffusion in NASICON-type Li_1+xTi_2−xAl_x(PO₄)₃(x=0, 0.3) Prepared by Mechanical Activation [J]. Ionics, 2008, 14(4): 303-311.

[14] Lee J. M., Kim S. H., Tak Y., . Study on the LLT Solid Electrolyte Thin Film with LiPON Interlayer Intervening Between LLT and Electrodes [J]. Journal of Power Sources, 2006, 163(1): 173-179.

[15] Abrahams I., Hadzifejzovic E. Lithium Ion Conductivity and Thermal Behaviour of Glasses and Crystallized Glasses in the System Li₂OAl₂O₃-TiO₂-P₂O₅ [J]. Solid State Ionics, 2000, 134(3–4): 249-257.

[16] Funke K., Banhatti R. D., Brückner S., . Ionic Motion in Materials with Disordered Structures: Conductivity Spectra and the Concept of Mismatch and Relaxation [J]. Phys. Chem. Chem. Phys., 2002, 4: 3 155-3 167.

[17] Funke K. Jump Relaxation in Solid Electrolytes [J]. Progress in Solid State Chemistry, 1993, 22: 111-195.

[18] Kumar B., Thokchom J. S. Space Charge Signature and Its Effects on Ionic Transport in Heterogeneous Solids [J]. J. Am. Ceram. Soc., 2007, 90(10): 3 323-3 325.