Synergistic Cu/Se Substitution and Dual Carbon Encapsulation in ZnS Enabling High-Rate Sodium Storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Zinc sulfide (ZnS) shows high theoretical capacity for sodium-ion batteries (SIBs).
• However, ZnS suffers from poor electron/ion kinetics and structural instability during cycling.
• Developing stable and efficient anodes is crucial for advancing SIB technology.

Purpose of the Study:

• To design and synthesize a synergistic Cu/Se dual-doped and dual carbon encapsulated ZnS (CuZnSSe@DC) anode.
• To investigate the impact of dual doping and carbon encapsulation on the electrochemical performance of ZnS anodes.
• To demonstrate the potential of advanced anode materials for high-performance SIBs.

Main Methods:

• Rational design of a composite anode material (CuZnSSe@DC).
• Electrochemical characterization including rate capability and cycling stability tests.
• Analysis of structural integrity and ion diffusion pathways.

Main Results:

• The Cu/Se dual doping enhanced charge transfer kinetics and created Na+ diffusion channels.
• The dual carbon encapsulation effectively mitigated volume expansion during cycling.
• CuZnSSe@DC exhibited a high-rate capability (193.1 mAh g-1 at 100 A g-1) and long cycle life (2500 cycles at 20 A g-1).

Conclusions:

• Synergistic cation/anion dual-doping engineering is effective for improving ZnS anode performance.
• The developed CuZnSSe@DC material demonstrates excellent potential for high-capacity and durable SIB anodes.
• This approach offers a promising strategy for next-generation sodium-ion battery development.