Unveiling the Electrolyte and Solid Electrolyte Interphase in Sodium Ion Batteries: Mechanisms, Progress, and...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium-ion batteries (SIBs) are a cost-effective alternative to lithium-ion batteries, owing to sodium's abundance.
• Electrolytes are critical for ion transport and electrochemical performance in SIBs.
• The solid electrolyte interphase (SEI) significantly impacts SIB performance and is influenced by electrolyte chemistry.

Purpose of the Study:

• To review and compare various electrolyte systems for SIBs.
• To discuss the formation and aging mechanisms of the SEI in SIBs.
• To provide perspectives on co-designing electrolytes and SEI for high-performance SIBs.

Main Methods:

• Literature review and comparative analysis of existing SIB electrolyte research.
• Discussion of SEI formation and degradation pathways.
• Synthesis of current understanding and future outlook on electrolyte-SEI synergy.

Main Results:

• Various electrolyte types (organic, aqueous, ionic liquids, gel, solid) have advanced for SIBs.
• SEI composition and formation are intrinsically linked to electrolyte properties.
• Understanding SEI mechanisms is key to optimizing SIBs through electrolyte modulation.

Conclusions:

• A comprehensive understanding of SEI structure and interfacial chemistry is vital for high-performance SIBs.
• Integrated design of electrolytes and SEI is a promising strategy for future SIB development.
• Further research is needed to bridge the gap between electrolyte modulation and SEI engineering.