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

Abstract

Chlorine-rich argyrodite Li 5.5 PS 4.5 Cl 1.5 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 Li 5.5 PS 4.5 Cl 1.5 on the electrochemical performances of related solid-state batteries is unclear. Herein, the electrochemical performances of LiNi 0.8 Mn 0.1 Co 0.1 O 2 /SE/Li–In SSBs with crystalline and glass-ceramic Li 5.5 PS 4.5 Cl 1.5 ( 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. • The influence of crystallinity of Li 5.5 PS 4.5 Cl 1.5 on battery performances is revealed. • Glass-ceramic Li 5.5 PS 4.5 Cl 1.5 affords superior electrochemical and mechanical stability . • Crystalline Li 5.5 PS 4.5 Cl 1.5 contributes to better capacity and rate performances. • Constructed SSB shows outstanding performance at −20 °C.