Electrochemical Perfomance of Fluorosurfactant Electrolyte Additives in Li-S Batteries and Their Contribution to Solid-Electrolyte Interface Formation

BSC-Ursa Minor 112

As fossil fuels deplete, there is an increasing demand for better energy storage. Conversion batteries undergo a different mechanism than commercial intercalation batteries. The first conversion material discovered, Li-S batteries, theoretically have greater specific energy and specific power compared to commercial Li-ion batteries but they lack the reversibility of commercial batteries due to the parasitic polysulfide shuttle that occurs. Fluorosurfactant electrolyte additives can promote the formation of a protective solid-electrolyte interface (SEI) on the anode, increasing reversibility, as shown in this study. Electrochemical performance of the additives is monitored by short-term galvanostatic cycling for preliminary screening shows the most promising electrolyte additives. The auspicious additives are then compared to the standard using both x-ray photoelectron spectroscopy (XPS) and galvanostatic long-term cycling. Ex-situ XPS shows the formation of the SEI, also compared to the standard. Screening of such electrolyte additives is necessary to fundamentally understand and improve upon the role they play in improving battery technology for next generation energy storage materials.