Electrolyte Solvation Structure Design for Sodium Ion Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium ion batteries (SIBs) are a promising post-lithium energy storage technology due to abundant sodium resources.
• Traditional electrolyte optimization for SIBs has focused on the solid electrolyte interphase (SEI) theory, which has limitations in explaining observed phenomena.
• Electrolyte solvation structure and electrode-electrolyte interface behavior are emerging as critical factors for improving SIB performance.

Purpose of the Study:

• To provide a systematic review of electrolyte solvation structures in SIBs, a topic not yet comprehensively covered.
• To elucidate specific solvation structure design guidelines and their impact on electrochemical performance.
• To offer new insights for optimizing electrolytes in high-performance SIBs and other battery systems.

Main Methods:

• Systematic survey and analysis of existing literature on SIB electrolytes.
• Discussion of the driving forces behind solvation structure formation.
• Review of recent advancements in tailoring SIB solvation structures.

Main Results:

• Identified limitations of the SEI theory in fully explaining SIB performance.
• Highlighted the significant influence of electrolyte solvation structure on electrochemical properties.
• Detailed key factors and strategies for manipulating solvation structures.

Conclusions:

• Electrolyte solvation structure is a critical design parameter for high-performance SIBs.
• Understanding and controlling solvation structures can overcome limitations of current SEI-centric approaches.
• This review provides a foundation for developing advanced electrolytes for SIBs and beyond.