Sol-gel synthesis of Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte

A modified sol-gel process was studied as applied to synthesize a lithium-conducting solid electrolyte of composition Li1.3Al0.3Ti1.7(PO4)(3) (LATP) using water-soluble salts Al(NO3)(3) center dot 9H(2)O, LiNO3 center dot 3H(2)O, and (NH4)(2)HPO4 and a titanium(IV) citrate complex. As-synthesized samples were characterized using X-ray powder diffraction, DSC/TG, SEM, and impedance spectroscopy. Sintering of as-synthesized amorphous powders at 700A degrees C was found to yield LATP with crystallite sizes of 42-48 nm. Ionic conductivity of the electrolyte measured in the frequency range 25-10(6) Hz in disks having 86-90% density that were sintered at 1000A degrees C was (3-4) x 10(-4) S/cm. Temperature-dependent ionic conductivity was studied in the range 25-200A degrees C. The activation energy of conduction was determined for LATP.