《Optimizing milling and sintering parameters for mild synthesis of highly conductive Li_5.5PS_4.5Cl_1.5 solid electrolyte》

All-solid-state batteries (ASSBs) with nonflammable solid electrolytes (SEs) are expected to improve the safety and specific energy compared with commercial lithium-ion batteries with liquid electrolytes. Among different kinds of SEs, chlorine-rich argyrodite electrolyte Li_5.5PS_4.5Cl_1.5 exhibit great potential for ASSBs, due to their high ionic conductivity and relatively inexpensive precursors. However, the traditional synthesis route not only requires high energy consumption, but also poses the risk of damaging the electrolyte due to high milling speed. Therefore, it is imperative to explore a gentler synthesis route for such electrolytes with large-scale preparation potential. Here, we undertook the investigation of two variables (ball milling speed and sintering temperature) on the synthesis of such electrolytes in the conventional route. The results indicate that the electrolyte with the conductivity of 7.96 mS cm^-1 can be obtained at a ball milling speed of 400 rpm and a sintering temperature of 400 ℃. At the increasing speed (550 rpm), a higher conductivity electrolyte (10.24 mS cm^-1) is produced. The solid-state battery assembled by the electrolyte and lithium titanate exhibited good electrochemical performance (a stable capacity of 116.4 mAh g^-1 at 2C after 100 cycles). Through our work, we endeavored to explore the impact of the key synthesis parameters on the preparation of high-performance electrolytes and advanced the development of high-performance all-solid-state Li-ion batteries.

https://pubs.rsc.org/en/content/articlelanding/2023/cc/d3cc05099h