Li2S2

Lithium disulfide, with the chemical formula Li2S2, is an inorganic compound. It is a salt formed from lithium cations (Li+) and disulfide anions (S2^2-). This compound is an example of a polysulfide, meaning it contains sulfur atoms linked together in a chain. The structure of the disulfide anion is typically a linear S-S bond. Li2S2 is known to be a solid at room temperature. Its preparation can involve reactions between lithium metal and sulfur, often under specific conditions to control the stoichiometry and prevent the formation of other lithium sulfides. Li2S2 has garnered interest in the field of energy storage, particularly as a cathode material in lithium-sulfur (Li-S) batteries. These batteries are a promising next-generation technology due to their high theoretical energy density. In Li-S batteries, Li2S2 can form during the discharge process and can be converted back to sulfur during charging. However, challenges remain in improving the cycling stability and efficiency of Li-S batteries incorporating Li2S2, including issues related to polysulfide dissolution and side reactions. Further research is ongoing to optimize its performance and overcome these limitations for practical applications.