Superior lithium dendrite suppression and air stability of dual Sc and O substituted Li-argyrodites and their enhanced cyclability in Li-batteries

Sulfide solid electrolyte has recently come to be considered a suitable electrolyte for lithium batteries because of its high ionic conductivity. However, it cannot be implemented in real time applications because of lithium dendrites and moisture sensitive issues. In this work, we solve the aforementioned issues through Sc2O3 sub-stitution on P and S-site in Li6PS5Cl structure. The prepared Sc2O3 substituted Li6PS5Cl shows an ionic con-ductivity values of 3.80 mS cm-1, which is somewhat lower compared to Li6PS5Cl (4.91 mS cm-1). Notably, after Sc2O3 substitution in Li6PS5Cl that boost up the interface stability with lithium. Moreover, it exhibits an excellent critical current density of 0.6 mA cm-2 than bare electrolyte (0.2 mA cm-2). Also, it shows the better DC cyclability at 0.2 and 0.3 mA cm-2 without internal short circuit after 200 cycles. Atmospheric stability analysis assures that the optimized electrolyte shows high tolerance against dry air. Finally, we assembled the battery that shows the discharge capacity of 183.3 mAh g-1, and the capacity is found to be retained over 94.5 % after 180 cycles. Importantly, the battery demonstrates a good discharge capacity of 139.9 mAh g-1 at 1C rate.

Automated summary

In this study, the issues of lithium dendrites and moisture sensitivity in sulfide solid electrolyte were addressed by substituting Sc2O3 on P and S-site in Li6PS5Cl structure. The Sc2O3 substituted Li6PS5Cl showed improved ionic conductivity, interface stability with lithium, DC cyclability, and atmospheric stability. The assembled battery exhibited high discharge capacity and good retention rate after cycling.