Highly Stable ZnS Anodes for Sodium-Ion Batteries Enabled by Structure and Electrolyte Engineering

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Zinc sulfide (ZnS) offers high capacity for sodium-ion battery anodes.
• Particulate ZnS suffers from pulverization, leading to battery failure.
• Developing stable ZnS anodes is crucial for practical sodium-ion battery applications.

Purpose of the Study:

• To engineer a stable zinc sulfide anode for high-performance sodium-ion batteries.
• To overcome the structural instability and capacity fading issues of ZnS anodes.
• To enhance the cycling stability and rate capability of conversion anodes.

Main Methods:

• Synthesized zinc sulfide encapsulated in a nitrogen-doped carbon shell (ZnS@NC).
• Investigated the structural stabilization provided by the nitrogen-doped carbon shell.
• Analyzed the formation of a robust solid electrolyte interphase (SEI) in ether-based electrolytes.

Main Results:

• The ZnS@NC anode demonstrated a reversible specific capacity of 584 mAh g⁻¹.
• Excellent rate capability was observed, with 327 mAh g⁻¹ at 70 A g⁻¹.
• Achieved highly stable cycling performance exceeding 10,000 cycles.

Conclusions:

• The nitrogen-doped carbon shell effectively stabilizes the ZnS active mass structure.
• The robust inorganic-rich SEI layer enhances cycling stability.
• ZnS@NC presents a viable strategy for developing stable, high-performance conversion anodes for sodium-ion batteries.