Synergistic Organic-Inorganic Interface Engineering for Stable Zinc Metal Anodes in Aqueous Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Aqueous zinc-ion batteries (AZIBs) face challenges with dendrite growth and corrosion, limiting their stability.
• Developing a stable solid electrolyte interphase (SEI) is crucial for enhancing Zn anode performance.
• The precise mechanisms of SEI-induced Zn anode stabilization require further elucidation.

Purpose of the Study:

• To in situ construct an ultrathin organic-inorganic hybrid SEI on Zn anodes using mercaptosuccinic acid (MSA).
• To investigate the mechanistic origin of Zn anode stabilization through the engineered SEI.
• To evaluate the electrochemical performance and long-term stability of MSA-modified Zn anodes in AZIBs.

Main Methods:

• In situ construction of a hybrid SEI (Zn-S-RCOOH) using mercaptosuccinic acid (MSA).
• Characterization of SEI structure and composition, including the organic outer layer and ZnS inner layer.
• Electrochemical testing of MSA/Zn anodes in symmetrical cells and full cells with MnO2 cathodes.

Main Results:

• The MSA-derived SEI effectively suppresses dendrite growth and corrosion by restructuring the interface and promoting (002) oriented Zn deposition.
• The MSA/Zn electrode demonstrated remarkable stability (>2400 h at 10 mA cm⁻² and >500 h at 81% DOD).
• Full cells utilizing MSA/Zn anodes exhibited high capacities and excellent capacity retention at various current densities.

Conclusions:

• The multifunctional MSA molecule enables the rational design of a robust organic-inorganic hybrid SEI for AZIBs.
• The engineered SEI enhances interfacial kinetics and promotes uniform Zn deposition, leading to superior electrochemical performance.
• This work provides a promising interfacial engineering strategy for developing durable and high-performance aqueous zinc metal batteries.