3/8Sr 7/16-3x/2La xZr 1/4Ta 3/4O 3 superionic solid electrolytes]]>

摘要

Oxide solid electrolytes Li3/8Sr7/16-3x/2LaxZr1/4Ta3/4O3(LSLZT, x?=?0, 0.025, 0.05) with different A-site vacancy were synthesized using conventional solid-state reaction procedure at 1300?°C. Approximately single-phase perovskite-type was obtained which was analyzed by X-ray diffraction. Moreover, scanning electron microscope, AC impedance spectroscopy and potentiostatic polarization measurement methods were adopted to study the microstructure, Li+conductivities and electronic conductivities of the samples, respectively. Among these samples, the optimal composition of Li3/8Sr7/16-3x/2LaxZr1/4Ta3/4O3(x?=?0.025) was selected with bulk conductivity of 1.26?×?10?3?S?cm?1, total conductivity of 3.30?×?10?4?S?cm?1, electronic conductivity of 6.60?×?10?9?S?cm?1at 30?°C and activation energy of 0.28?eV. Furthermore, the cyclic voltammogram analysis indicated the stability of this solid electrolyte at voltages higher than 1.3?V against metallic lithium. The solid electrolyte as a separator in LiFePO4/Li half-cell showed good cycle performance that comprises 98.7% of original values at 0.2?C charge-discharge rates after 50 cycles.