In this study, the compound Li3BO3 (LBO) is intended to be prepared by a polymeric complex method as a sintering aid for the densification of Li7La3Zr2O12 (LLZ) solid electrolyte. A polymeric precursor containing Li and B is heat-treated in an air atmosphere at a temperature range between 600℃ and 800℃. Instead of LBO, the compound Li2+xC1-xBxO3 (LCBO) is unexpectedly synthesized after a heat-treatment of 700℃. The effect of LCBO addition on sintering behavior and ion conductivity of LLZ is studied. It is found that the LCBO compound could lead to significant improvements in the densification and ionic conductivity of LLZ compared to pure LLZ. After sintering at 1100℃, the density of the LLZ-12wt%LBO composite is 3.72 g/cm3, with a high Li-ion conductivity of 1.18 × 10-4 Scm-1 at 28℃, while the pure LLZ specimen had a densify of 2.98 g/cm3 and Li-ion conductivity of 5.98 × 10−6 Scm-1.

A thick film of Li7La3Zr2O12 (LLZO) solid-state electrolyte is fabricated using the tape casting process and is compared to a bulk specimen in terms of the density, microstructure, and ion conductivity. The final thickness of LLZO film after sintering is 240 μm which is stacked up with four sheets of LLZO green films including polymeric binders. The relative density of the LLZO film is 83%, which is almost the same as that of the bulk specimen. The ion conductivity of a LLZO thick film is 2.81 × 10−4 S/cm, which is also similar to that of the bulk specimen, 2.54 × 10−4 S/ cm. However, the microstructure shows a large difference in the grain size between the thick film and the bulk specimen. Although the grain boundary area is different between the thick film and the bulk specimen, the fact that both the ion conductivities are very similar means that no secondary phase exists at the grain boundary, which is thought to originate from nonstoichiometry or contamination.

Porous thick film of alumina which is fabricated by freeze tape casting using a camphene-camphor-acrylate vehicle. Alumina slurry is mixed above the melting point of the camphene-camphor solvent. Upon cooling, the camphene- camphor crystallizes from the solution as particle-free dendrites, with the Al2O3 powder and acrylate liquid in the interdendritic spaces. Subsequently, the acrylate liquid is solidified by photopolymerization to offer mechanical properties for handling. The microstructure of the porous alumina film is characterized for systems with different cooling rate around the melting temperature of camphor-camphene. The structure of the dendritic porosity is compared as a function of ratio of camphene-camphor solvent and acrylate content, and Al2O3 powder volume fraction in acrylate in terms of the dendrite arm width.