Properties of aerosol deposited NASICON-type Li1.5Al0.5Ge1.5(PO4)3 solid electrolyte thin films

NASICON-type Li1.5Al0.5Ge1.5(PO4)(3) (LAGP) solid electrolyte thin films were fabricated without any heat treatment by aerosol deposition (AD). Ball-milled LAGP powders with different particle sizes were used as raw material and deposited directly on a stainless steel substrate via room temperature impact consolidation. X-ray diffraction patterns revealed that as-deposited LAGP film has a same crystal structure with raw LAGP powder and no secondary phases are formed during deposition. SEM observation showed that film consists of fractured LAGP nanoparticles but the porosity is strongly influenced by an averaged particle size of raw LAGP powder. Maximum total (bulk+grain-boundary) ionic conductivity at room temperature in aerosol deposited (ADed) LAGP film was 0.5 x 10(-5) S cm(-1), while the bulk conductivity of film was approximately 10(-4) S cm(-1), which is comparable with the bulk property of LAGP as previously reported. Therefore, lower total conductivity of ADed LAGP film is mainly attributed to large grain-boundary resistance between the LAGP nanoparticles in the film. Improvement of film density and the connectivity among the LAGP nanoparticles in the film should be needed to enhance the total conductivity. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.