Li2S, or lithium sulfide, is a chemical compound composed of two lithium atoms and one sulfur atom. It is a white crystalline solid that is primarily used in batteries, particularly in lithium-ion batteries, due to its high energy density and ability to improve battery performance. In addition to its use in batteries, Li2S has applications in the production of glass and ceramics. It can also serve as a precursor for other lithium compounds, which are important in various industrial processes. Its unique properties make it a valuable material in both energy storage and manufacturing.