Progress on Designing Artificial Solid Electrolyte Interphases for Dendrite-Free Sodium Metal Anodes

Abstract

Nature-abundant sodium metal is regarded as ideal anode material for advanced batteries due to its high specific capacity of 1166 mAh g−1 and low redox potential of −2.71 V. However, the uncontrollable dendritic Na formation and low coulombic efficiency remain major obstacles to its application. Notably, the unstable and inhomogeneous solid electrolyte interphase (SEI) is recognized to be the root cause. As the SEI layer plays a critical role in regulating uniform Na deposition and improving cycling stability, SEI modification, especially artificial SEI modification, has been extensively investigated recently. In this regard, we discuss the advances in artificial interface engineering from the aspects of inorganic, organic and hybrid inorganic/organic protective layers. We also highlight key prospects for further investigations.

Na metal anodes for liquid and solid-state Na batteries

“…2. Although there have been several excellent review papers summarizing the development and understanding of Na metal anodes for the NMBs, 13,55–62 the majority of them are focused on the NMBs that employ liquid-state electrolytes. The SSNMBs have attracted increasing attention because of their high energy density and safety in recent years.…”

A Rooted Multifunctional Heterogeneous Interphase Layer Enabled by Surface‐Reconstruction for Highly Durable Sodium Metal Anodes

“…This is because an ideal SEI film should not only possess superior structure and beneficial components with large mechanical strength, high ionic (Na + ) conductivity, and sodiophilic properties simultaneously but also have a tight combination with a metal electrode, thereby alleviating the delamination and fracture of the SEI layer during plating-stripping processes. [39][40][41][42] Therefore, constructing a rooted SEI interphase layer with multifunc-tional components and exerting their respective strengths is speculated to be an advisable method to achieve dendrite-free SMAs and lengthen the cycle life of SMBs.…”