Scalable areal capacity of SbSxCy+z micro-thin-film cathodes for lithium-metal polysulfide batteries

The wearable electronics and nanorobotics demand high energy density devices such as thin-film solid-state lithium-sulfur (Li-S) or lithium-metal polysulfide (Li-MSx) batteries on a small footprint area, which requires the adoption of modern thin-film fabrication technologies. The fabrication of efficient sulfur based thin film cathodes with a stable cycling performance for Li-MSx batteries is a serious challenge because of the insulating nature and low meting point of sulfur. Herein, we have developed highly conductive thin film cathodes of amorphous SbSxCy+z with chemically bonded sulfur by adopting magnetron sputtering, and the cycling stability was enhanced by fluorinated ethylene carbonate (FEC) as an electrolyte additive. The thin film metal polysulfide cathode is used directly to build Li-MSx battery with FEC modified electrolyte, which exhibits an excellent cyclic stability, commendable rate capability, and high areal capacity of 250 μAh/cm2 for at least 150 cycles. This study offers an opportunity to fabricate shuttle-effect free robust Li-MSx batteries with stable cycling performance.