SYNTHESIS AND STUDY OF ELECTROCHEMICAL CHARACTERISTICS OF Ta-DOPED SOLID ELECTROLYTE Li7La3Zr2O12

The process of synthesis of Ta-substituted lithium-conducting solid electrolyte powders with nominal composition Li6,52Al0,08La3Zr1,75Ta0,25O12 (Ta-LLZ) by melting a charge consisting of low-melting crystallohydrates ZrO(NO3)2∙2H2O, La(NO3)3∙6H2O and Al(NO3)3∙9H2O, followed by solid-phase sintering, is investigated. On the basis of X-ray phase and differential thermal analysis, the conditions for the formation of a monophase cubic Ta-LLZ that does not contain nonconducting impurity phases La2Zr2O7 and La2O3 are established. The ionic (~1.1·10–4 S·cm–1) and electron conductivity (<1.7‧10–9 S·cm–1) were determined by electrochemical impedance spectroscopy and potentiostatic chronoamperometry. Based on the studied electrochemical characteristics, Ta-LLZ is a promising material for all solid-state lithium-ion batteries.