The structural impact of sintered and flame-synthesized Li ceramics on ionic conductivity in solid battery electrolytes

Ionic conductivity is generally much lower in solid electrolytes as compared to polymer gel electrolytes. For solid electrolytes, dramatic changes in conductivity can occur depending on the method of Li ceramic production. Production of lithium salt is generally done using a ball mill followed by sintering at about 1300°C. This leads to rather coarse, micron-size particles. Flame synthesis has many advantages over methods such as hydrothermal synthesis including: no separation step after synthesis; no need for sintering of the products (spray flames are typically about 2,500°C); rapid, low-cost production of moderate quantities on a lab-scale setup (one kilogram in 4 hours); demonstrated scale-up to pilot plant and industrial production; pristine and well-mixed compositions with low impurity content; absence of surface hydroxyls that could prove reactive to lithium ions; as well as control over particle size, surface area, aggregation, and branch content. In this study, we attempt to explore the structural impact on ionic conductivity in solid electrolytes for both sintered and flame-synthesized Li ceramic particles