Engineering Electrolyte Network Structure for Improved Kinetics and Dendrite Suppression in Zn-S Batteries.

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc-sulfur (Zn-S) batteries offer a safer, lower-cost alternative to lithium-ion batteries.
• Key challenges include slow sulfur cathode kinetics and poor zinc anode stability.

Purpose of the Study:

• To enhance the performance of aqueous Zn-S batteries.
• To address limitations in sulfur cathode conversion and zinc anode stability.

Main Methods:

• Tuning electrolyte structure with propylene glycol methyl ether (PM) as a co-solvent and ZnI2 as an additive.
• Utilizing experimental and theoretical calculations to analyze electrolyte-electrode interactions.
• Investigating the role of PM as a redox mediator for sulfur and its effect on zinc anode stability.

Main Results:

• PM's electron-donating groups facilitate the I-/I3- redox reaction, improving sulfur cathode reversibility.
• PM enhances zinc anode electron transfer and anion decomposition, stabilizing the anode interface.
• The synergistic effect resulted in a capacity of 1456 mAh g-1 and energy density of 471.8 Wh kg-1.

Conclusions:

• The optimized electrolyte system significantly improves the performance of aqueous Zn-S batteries.
• PM acts as a crucial redox mediator and interfacial stabilizer.
• This approach presents a viable strategy for developing high-performance aqueous energy storage devices.