Ultrafast Sintering of Solid-State Electrolytes with Volatile Fillers

Enhancing the performance of ceramic solid-state electrolytes (SSEs) often relies on incorporating effective fillers. However, the choice of fillers is often limited to only a few highly stable ones, as the long-term sintering by conventional methods often leads to severe loss of volatile components. Herein, we develop an ultrafast sintering method for SSEs with volatile fillers toward a dense and high-performance membrane. Using Ta-doped Li7La3Zr2O12 (LLZTO) as a model system, we sinter a Li3N/LLZTO composite SSE, which shows a higher relative density, a higher ionic conductivity, and a reduced electronic conductivity compared to the pristine LLZTO. In contrast, no Li3N can be observed in the membrane sintered by a conventional furnace due to its high volatility. This study opens up a new route for the rational selection of fillers in a much broader space toward synthesizing high-quality and high-performance ceramic SSEs.