Unraveling the crystallinity on battery performances of chlorine-rich argyrodite electrolytes

Chlorine-rich argyrodite Li5.5PS4.5Cl1.5 presents great potential for the application of solid-state batteries (SSBs) due to the high ionic conductivity and relatively low cost. However, the effect of crystallinity for Li5.5PS4.5Cl1.5 on the electrochemical performances of related solid-state batteries is unclear. Herein, the electrochemical performances of LiNi0.8Mn0.1Co0.1O2/SE/Li–In SSBs with crystalline and glass-ceramic Li5.5PS4.5Cl1.5 (c- and gc-LPSC) electrolytes are carefully investigated. Electrochemical tests show that SSBs using c-LPSC electrolytes deliver higher capacities and better rate performances than that of gc-LPSC electrolytes at different operating temperatures due to the higher Li-ion conductivity of the former. Moreover, the optimized solid-state battery delivers an initial discharge capacity of 120.2 mAhg-1 at 5C and maintains 64% of the capacity after 3500 cycles under room temperature. At an elevated temperature (60 °C), a much higher discharge capacity of 145.5 mAh g-1 is achieved and 80.8% of the capacity is sustained after 500 cycles. This work unravels the influence of the crystallinity of argyrodite electrolytes on the intrinsic properties, providing a guiding significance for the construction of high-performance solid-state batteries.