For the first time, glass-ceramic particles (LATP and LLZO) have been processed with both a tumbling-mixer and a kneader on semi-industrial scale. Although sintered LATP and LLZO discs reveal a statistically negligible ionic interface resistance to PEO with LiTFSI, the total conductivity of dispersed particles within a PEO-LiTFSI matrix is only slightly enhanced at 80 °C. However, for a tumbling mixing process, SEM investigations prove insufficient contact of particles within the matrix as well as agglomerates, cracks and voids. With the shear intensive kneader, dense and homogeneous samples were obtained. Compared to nanometer-sized SiO2 particles, the LATP filler enable an increase of the ionic conductivity of the hybrid PEO system by a factor of about two. These finding help to overcome solvent-based mixing processes that may cause uncontrolled decomposition and surface reactions of filler particles thereby changing microscopic conduction mechanisms in the hybrid electrolytes.
As the ionic conductivity of solid-state lithium ion conductors rises, knowledge of the detailed conductivity mechanisms is harder to obtain due to the limited frequency resolution of the traditional impedance spectrometers. Moreover, the data is easily affected by the local microstructure (i.e. pores, grain-boundaries) and the preparation conditions. The aim of this work is to demonstrate the feasibility of the coaxial reflection technique as a reliable tool to study fast ionic conductors (i.e. σ > 10−4 S cm−1). Especially the relative permittivity can be determined more accurately at room temperature. For the first time the electrical performance of LATP and LLZO manufactured via a scalable top-down glass-ceramic route is evaluated. The density turns out to be a key parameter influencing both relative permittivity and resulting conductivities. For a 100% dense LATP sample the coaxial reflection technique reveals a high grain-core conductivity of 6 × 10−3 S cm−1 similar to the conductivity of ideal single crystals.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.