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.