F64: Advances in Li-ion and Li-S Energy Storage

Tue. March 5, 9:48 a.m. – 10:00 a.m. CST

211AB

Energy storage has become one of the most important topics in the field of green energy production. With the rise in renewable energy generation, the demand for high-energy-density batteries is also increasing to match storage needs. Conventional intercalation-based lithium-ion batteries are reaching a performance ceiling in terms of energy density and face problems with dendritic plating behavior and scarcity of source materials. Unlike intercalation-based batteries, conversion batteries release energy by breaking chemical bonds on the cathode side, rather than inserting ions into a crystalline cathode. Sulfur, as one of the promising cathode materials, has benefits such as low toxicity and cost relative to other cathode materials and large natural abundance. This material consists of multiple eight-membered sulfur rings that are held together by van der Waals forces. By using density functional theory, we modeled reactions for Li-S and Ca-S batteries, where sulfur rings are broken forming various  and  () polysulfides. We are specifically interested in calculating the voltage profile, reaction mechanisms, structural change upon charge, and discharge process. We demonstrate the importance of including the electrolyte in the voltage simulations, which allows for the proper treatment of the polysulfide species. A voltage profile is constructed for both calcium-sulfur and lithium-sulfur system using one common electrolyte.