High-Energy Lithium-Sulfur Batteries

1. CNMS User Project Highlight High-Energy Lithium-Sulfur Batteries • Scientific Achievement • An electrolyte additive, phosphorous pentasulfide(P2S5), is found to react with lithium metal in Li-S batteries to form a protective coating that conducts lithium ions and improves Coulombic efficiency. The coating blocks the polysulfide shuttle from the lithium anode, which is a key challenge to the longevity of Li-S batteries. • Significance • With a theoretical energy density 3-5 times higher than that of lithium-ion batteries, Li-S batteries are the most promising next generation of high-energy batteries. The deployment of Li-S batteries is hampered by their poor cyclability due to the polysulfide shuttle phenomenon, which causes Li2S to precipitate deleteriously in the cell. • Research Details • CNMS Capability: Expertise in synthesis and characterization of inorganic nanomaterials. • A Li-S test cell demonstrates a high reversible capacity of 900-1350 mAh g-1 and a high Coulombic efficiency of ≥90% for at least 40 stable cycles at 0.1 C. The function of the P2S5 additive is two-fold: P2S5passivates the surface of lithium metal and therefore eliminates the polysulfide shuttle phenomenon; and P2S5promotes the dissolution of Li2S and alleviates the loss of capacity caused by the precipitation of Li2S. Shown above are the capacity and efficiency for cells with and without the new protective coating. Z. Lin, Z. Liu, W. Fu, N. J. Dudney, C. Liang, Adv. Funct. Mater. DOI: 10.1002/adfm.201200696. (2012).