Engineering Aqueous Electrolytes with Vicinal S-based Organic Additives for Highly Reversible Zinc-Ion Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc-ion batteries (AZIBs) face challenges like dendrite formation, hydrogen evolution reaction (HER), and corrosion, hindering commercialization.
• Conventional electrolyte additives often promote unfavorable (002) zinc deposition, leading to structural instability.

Purpose of the Study:

• To address the limitations of AZIBs by introducing a novel electrolyte additive, 3,3 -dithiobis-1-propanesulfonic acid disodium salt (SPS).
• To investigate the mechanism by which SPS enhances zinc anode stability and battery performance.

Main Methods:

• SPS, a symmetrical sulfur-based organic salt, was employed as an electrolyte additive in AZIBs.
• The adsorption behavior and electrochemical performance of the SPS-modified zinc anode were analyzed.
• Zinc/NaV3O8·1.35H2O full cells were assembled and tested to evaluate long-term cycling stability and capacity retention.

Main Results:

• SPS facilitated dense (100) zinc growth via a unique adsorption network, ensuring structural uniformity and compactness of the zinc deposit.
• The additive effectively mitigated HER and corrosion by blocking electrolyte access and promoting Zn2+ transport and desolvation.
• Sustained cycling over 1100 hours at 5 mA cm-2, 5 mAh cm-2, and stable operation at 15 mA cm-2, 15 mAh cm-2 were achieved with 99.41% Coulombic efficiency.
• The Zn/NaV3O8·1.35H2O cell with SPS additive demonstrated excellent cycling stabilization and 95.5% capacity retention.

Conclusions:

• SPS acts as a dual-action additive, improving zinc anode stability through controlled deposition and mitigation of parasitic reactions.
• The findings provide valuable insights for the development of high-performance and durable AZIBs and other metal-based battery systems.