Lithium sulfide: a promising prelithiation agent for high‐performance lithium‐ion batteries

Lithium‐ion batteries are widely used in portable electronics and electric vehicles due to their high energy density, stable cycle life, and low self‐discharge. However, irreversible lithium loss during the formation of the solid electrolyte interface greatly impairs energy density and cyclability. To compensate for the lithium loss, introducing an external lithium source, that is, a prelithiation agent, is an effective strategy to solve the above problems. Compared with other prelithiation strategies, cathode prelithiation is more cost‐effective with simpler operation. Among various cathode prelithiation agents, we first systematically summarize the recent progress of Li2S‐based prelithiation agents, and then propose some novel strategies to tackle the current challenges. This review provides a comprehensive understanding of Li2S‐based prelithiation agents and new research directions in the future.