Interface Chemistry and Reaction Pathway Regulation for Boosted Redox Kinetics in Aqueous Zn-S Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous Zn-S batteries offer high capacity and energy density for grid storage.
• Sluggish redox kinetics and stability issues hinder their practical application.

Purpose of the Study:

• To develop an interface chemistry regulator for enhancing Zn-S battery performance.
• To investigate the role of tetramethylurea (TTMU) as an electrolyte additive for both cathode and anode.

Main Methods:

• Tetramethylurea (TTMU) was used as an electrolyte additive.
• Electrochemical performance was evaluated using Zn-S battery cells.
• Interfacial properties and reaction mechanisms were analyzed.

Main Results:

• TTMU additive reduced reaction energy barriers and promoted uniform ZnS nucleation.
• An effective solid-electrolyte interphase formed on the Zn anode, enhancing plating/stripping reversibility.
• The Zn-S battery with 10% TTMU achieved 1620 mAh g^-1 at 0.1 A g^-1, outperforming the benchmark.
• Capacity significantly increased from 48 to 913 mAh g^-1 at 5 A g^-1 with TTMU.

Conclusions:

• TTMU acts as an effective interface chemistry regulator for aqueous Zn-S batteries.
• The additive significantly improves reaction kinetics, electrode stability, and overall battery performance.
• TTMU holds promise for advancing high-performance aqueous energy storage systems.