Recent progress on lithium anode protection for lithium–sulfur batteries: Review and perspective

Lithium–sulfur batteries (LSBs) are called to complement current state-of-the-art lithium-ion devices. However, despite the optimization of cathode and electrolyte, the usage of metallic lithium as anodic material is linked to several problems that give place to the constant degradation of the anode. These degradation processes become the main bottleneck for LSBs and their real application; therefore, solving these challenges related to lithium metal anode (LMA) becomes the priority. Recent investigations and development have advanced the protection of LMA with the formation of a mechanically stable and ionically conductive solid-electrolyte interphase on top of the LMA surface. In this perspective, we review the most promising recent in situ and ex situ lithium protection techniques, with our perspective on their potential scalability from laboratory to industry. Most importantly, the strategies to obtain a long-cycle-life, high-energy-density, and commercial LSBs are suggested.