A Highly Reversible Room-Temperature Sodium Metal Anode

作者：Seh, Zhi Wei; Sun, Jie; Sun, Yongming; Cui, Yi^*

来源：ACS Central Science, 2015, 1(8): 449-455.

DOI：10.1021/acscentsci.5b00328

• CHLOROALUMINATE MOLTEN-SALTS
• LITHIUM-SULFUR BATTERIES
• ION BATTERIES
• RECHARGEABLE BATTERIES
• INERT ELECTRODES
• ENERGY-STORAGE
• ELECTROLYTES
• PERFORMANCE
• STABILITY
• LI

Owing to its low cost and high natural abundance, sodium metal is among the most promising anode materials for energy storage technologies beyond lithium ion batteries. However, room-temperature sodium metal anodes suffer from poor reversibility during long-term plating and stripping, mainly due to formation of nonuniform solid electrolyte interphase as well as dendritic growth of sodium metal. Herein we report for the first time that a simple liquid electrolyte, sodium hexafluorophosphate in glymes (mono-, di-, and tetraglyme), can enable highly reversible and nondendritic plating-stripping of sodium metal anodes at room temperature. High average Coulombic efficiencies of 99.9% were achieved over 300 plating-stripping cycles at 0.5 mA cm(-2). The long-term reversibility was found to arise from the formation of a uniform, inorganic solid electrolyte interphase made of sodium oxide and sodium fluoride, which is highly impermeable to electrolyte solvent and conducive to nondendritic growth. As a proof of concept, we also demonstrate a room-temperature sodium-sulfur battery using this class of electrolytes, paving the way for the development of next-generation, sodium-based energy storage technologies.

• 出版日期2015-11-25