A Novel Sultone-Based Electrolyte Additive for Ultra-Long Cycle Life Sodium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium-ion batteries (SIBs) are promising energy storage devices.
• Limited cycle life remains a significant barrier to SIB industrialization.
• Electrolyte formulation is critical for improving SIB stability.

Purpose of the Study:

• To develop a practically viable electrolyte with enhanced cycling stability for SIBs.
• To investigate the synergistic effects of sulfone and borate additives on interfacial layer formation.
• To provide insights for the industrial scale-up of long-life SIB electrolytes.

Main Methods:

• Formulation of an optimized electrolyte using NaPF6 in PC/EMC with PES and NaODFB additives.
• Analysis of interfacial layer evolution through electrochemical testing and surface characterization.
• Demonstration of cycling performance in a Na||NVP half-cell.

Main Results:

• The optimized electrolyte with PES and NaODFB additives promotes the formation of uniform, compact, and stable CEI/SEI layers.
• Cooperative interfacial evolution leads to enhanced cycling stability.
• The Na||NVP half-cell demonstrated excellent long-term cycling, retaining 96.7% capacity after 5000 cycles.

Conclusions:

• The synergistic action of sulfone and borate additives effectively improves SIB cycling stability.
• The developed electrolyte offers a promising solution for industrial SIB applications.
• This research provides valuable experimental support for the commercialization of long-life SIBs.