Preparation and electrical properties of LISICON-type lithium zinc silicate from aqueous solution

Abstract

Lithium zinc silicate (Li₃Zn_0.5SiO₄) is a structural analog of the lithium superionic conductor (LISICON) family. In this study, we synthesized a LISICON-type lithium zinc silicate, namely Li₃Zn_0.5SiO₄, from an aqueous solution and found that the electrical conductivity was improved after loading the silicate with 0 to 0.10 mol % Cr, Co, or Ni. X-ray diffraction (XRD) analysis revealed that single-phase Li₃Zn_0.5SiO₄ was obtained at 900 °C for 5 h. The Li₃Zn_0.5SiO₄ exhibited a similar phase to that of basic Li₃Zn_0.5SiO₄ when loaded with less than 0.05 mol % of Cr, Co, or Ni. The electrical conductivity of the synthesized Li₃Zn_0.5SiO₄ was found to be 3.12 × 10⁻⁷ and 2.13 × 10⁻² S·cm⁻¹ at 50 and 300 °C, respectively. The addition of Cr, Co, or Ni to the Li₃Zn_0.5SiO₄ further enhanced the electrical conductivity. Li₃Zn_0.45Ni_0.05SiO₄ exhibited an electrical conductivity of 7.54 × 10⁻⁶ and 4.35 × 10⁻² S·cm⁻¹ at 50 and 300 °C, respectively.