Wednesday, 4 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
We report the synthesis of several carbon encapsulated lithium sulfide (Li2S@C) composites via aerosol spray pyrolysis (ASP), followed by an investigation of the electrochmical properties as cathodes in lithium-sulfur batteries. In this work we show that the challenges of the sulfur cathode, electrical insulation as well as polysulfide dissolution can be addressed by the arrangement of the active cathode material inside amorphous carbon confinement, accomplished with the simple, scalable manufacturing technique of ASP. In this method, ASP is first used to generate composite particles of dispersed lithium carbonate within amorphous carbon (Li2CO3@C). We show that ASP method can generate the Li2CO3@C composite from various water-soluble precursors including lithium acetate (CH3COOLi), lithium nitrate (LiNO3) or lithium carbonate, respectively, all of which yield Li2CO3 under identical reaction conditions. Sucrose is used as the carbon precursor. The obtained Li2CO3@C composites are post-treated to yield a Li2S@C composite using mixed hydrogen sulfide/argon gas (H2S/Ar at 5/95 vol.%) at evaluated temperature. The selection of precursors has an impact on particle morphology, and as such on electrochmical performance.