Fe-P-S electrodes for all-solid-state lithium secondary batteries using sulfide-based solid electrolytes

Although lithium-sulfur batteries are expected to be the next-generation high-capacity battery of choices, the sulfur electrodes studied so far contain large amounts (typically 30-60 wt%) of carbon additives, resulting in low energy density. In this study, an Fe-P-S-based material is prepared and characterized for the use as a sulfur electrode with a low content of carbon additives. The electrode material based on Fe-P-S is synthesized by the mechanical milling of FePS3 and elemental sulfur. The ball-milled 70FePS(3)center dot 30S (wt%) electrode comprises FeS2 particles of similar to 30 nm in size and amorphous P-S. The all-solid-state battery operated at 100 degrees C exhibits a reversible capacity of more than 625 mAh g(-1) for 50 cycles at 0.51 mA cm(-2) (similar to 0.1C) in spite of the low carbon content (2 wt%) in the electrode. During the discharge-charge cycle, the sulfur component is confirmed to be both reduced and oxidized, cyclically.