Sol-Gel Synthesis of Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3 Solid Electrolyte

摘要

A modified sol-gel process was studied as applied to synthesize a lithium-conducting solid electrolyte of composition Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3 (LATP) using water-soluble salts Al(NO_3)_3 ? 9H_2O, LiNO_3 -3H_2O, and (NH_4)_2HPO_4 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 700°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 1000°C was (3-4) ×10~(-4) S/cm. Temperature-dependent ionic conductivity was studied in the range 25-200°C. The activation energy of conduction was determined for LATP. '