Critical effects of electrolyte recipes for Li and Na metal batteries

The pursuit of rechargeable batteries with high energy density has triggered enormous efforts in developing Li/Na metal batteries considering the extremely high specific capacity of Li/Na metal anodes. As is typical for a new battery system, electrolyte design should immediately keep up with the specific electrode chemistry. This is especially true since Li/Na metal anodes face the problems of dendritic growth, hyper-reactivity, and an intrinsic safety concern, but the conventional electrolytes used for Li/Na-ion batteries fall short in sustaining their stable cyclability. Here, we intend to identify and elucidate the critical effects brought by the electrolyte recipes in stabilizing Li/Na metal batteries. In addition, the working mechanism of fluoroethylene carbonate (FEC) and the controversial role of LiF were reviewed. Based on a thorough discussion on these effects, we propose strategies that should be taken further. Finally, the remaining open questions and potential research directions for future development have been emphasized.

Automated summary

This paper discusses the critical effects of electrolyte design on the stability of Li/Na metal batteries, reviews the working mechanism of fluoroethylene carbonate (FEC) and the controversial role of LiF, and proposes strategies for further development based on a thorough discussion of these effects.