In Situ Localized Polysulfide Injector for the Activation of Bulk Lithium Sulfide

The activation of commercial Li₂S remains to be one of the key challenges against its commercialization as a starting cathode material for a sulfur-based Li-ion battery system. In this work we take advantage of the lower oxidation potential of commercial Na₂S (1-3 wt%) to serve as an in situ and local polysulfide injector for the activation of commercial Li₂S (70 wt%). In contrast to applying pre-solvated redox mediators, this technique allows for the activation of commercial Li₂S at lower voltages with an electrolyte content as low as 3 μL mg^-1_Li at 3 mgmg_Li cm^-2 and 4 μL mg^-1_Li at 6.5 mg_Li cm^-2 without any other material modification.