Methods and Cost Estimation for the Synthesis of Nanosized Lithium Sulfide

Lithium sulfide (Li 2 S) is an alternative cathode material for lithium‐sulfur batteries. It can mitigate the volume expansion problem encountered by the sulfur cathode, in addition, as a fully lithium‐inserted cathode, it can be paired with lithium‐free anodes or be assembled into anode‐free batteries. However, commercially available Li 2 S powder delivers poor electrochemical performances due to the significant potential barrier during the first charging process, and therefore developing inexpensive synthesis route for nanosized Li 2 S with small diameter and low charging overpotential becomes the key to the construction of practical Li 2 S cathode. Herein, the preparation methods for Li 2 S nanoparticles are summarized, including laboratory synthesis methods and potential large‐scale preparation routes; traditional industrial synthesis methods for commercially available Li 2 S are also attached as references. In particular, the scalability of these methods is mentioned, and the costs of the resulted Li 2 S products are also estimated and compared with the currently used cathode materials for Li‐ion batteries. In the end, the commercially worthwhile research pathways for Li 2 S synthesis as well as the perspective on the practical production of Li 2 S are discussed. Useful guidance for the selection of practical Li 2 S synthesis routes is also provided.