(491d) Effects of Amino Thiophenol Additives on the Solid-Electrolyte Interphase in Lithium-Sulfur Battery

Lithium-sulfur (Li-S) batteries have been considered a promising candidate for the next generation of battery systems owing to their high specific capacity and energy density. However, some barriers hinder the application of Li-S batteries, such as the “shuttle effects” of lithium polysulfides (LPS), the poor electrical conductivity of sulfur, and lithium dendrite on lithium metal electrodes. Herein, we investigated a series of amino thiophenol: p-phenylenediamine (PP), 2-amino thiophenol (2-ATP), 3-amino thiophenol (3-ATP), and 4-amino thiophenol (4-ATP) as an electrolyte additive to form a stable and uniform solid electrolyte interphase (SEI) to protect the Li metal anode. Additionally, the stable SEI layer can prevent the Li metal anode from reacting with soluble LPS. The application of additives in Li-S batteries can improve their electrochemical performance. 4-ATP has the best electrochemical performance and exhibited an initial specific capacity of 1379 mAh/g and reversible specific capacity of 1108 mAh/g after 100 cycles. The morphology and composition of the SEI layers are examined by SEM and XPS. This study reveals the possibility of employing amino thiophenol to form a stable and smooth SEI layer that ameliorates lithium dendrite problems and avoids LPS reactions with Li metal.