Mass Production of Customizable Core-Shell Active Materials in Seconds by Nano-Vapor Deposition for Advancing Lithium Sulfur Battery.

Rational design and scalable production of core-shell sulfur-rich active materials is vital for not only the practical success of future metal-sulfur batteries but also for a deep insight into the core-shell design for sulfur-based electrochemistry. However, this is a big challenge mainly due to the lack of efficient strategy for realizing precisely controlled core-shell structures. Herein, by harnessing the frictional heating and dispersion capability of the nanostorm technology developed in the authors' laboratory, it is surprisingly found that sulfur-rich active particles can be coated with on-demand shell nanomaterials in seconds. To understand the process, a micro-adhesion guided nano-vapor deposition (MAG-NVD) working mechanism is proposed. Enabled by this technology, customizable nano-shell is realized in a super-efficient and solvent-free way. Further, the different roles of shell characteristics in affecting the sulfur-cathode electrochemical performance are discovered and clarified. Last, large-scale production of calendaring-compatible cathode with the optimized core-shell active materials is demonstrated, and a Li-S pouch-cell with 453 Wh kg -1 @0.65 Ah is also reported. The proposed nano-vapor deposition may provide an attractive alternative to the well-known physical and chemical vapor deposition technologies.