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

• Published in: SusMat (Online) Vol. 4; no. 1; pp. 34 - 47
• Main Authors: Huang, Junkang, Li, Weifeng, Zhang, Wenli, Lin, Bixia, Wang, Yang, Or, Siu Wing, Sun, Shuhui, Xing, Zhenyu
• Format: Journal Article
• Language: English
• Published: Wiley 01.02.2024
• Subjects: Li2S; Li‐ion batteries; metallothermic reduction reaction; prelithiation; prelithiation agent
• ISSN: 2692-4552; 2692-4552
• DOI: 10.1002/sus2.177

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. As a prelithiation agent, Li2S irreversibly release active Li+ during the first few charging process. The delithiation potential of Li2S prelithiation agent is lower than that of cathode materials, therefore the SEI formation consumes the Li+ of the Li2S prelithiation agent, rather than cathode materials, during the first charge process. In the discharge process, the oxidized cathode material of higher redox potential holds the priority to combine with the released Li+ from the anode side. The above process implies an irreversible lithiation/delithiation process, leading to a sacrificial role for Li2S prelithiation agents.