Trimethylolethane-mediated electric double layer engineering for dendrite-free zinc anodes

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc ion batteries (AZIBs) are promising for large-scale energy storage.
• Stabilizing zinc anodes and their interfaces is crucial for AZIB performance.
• Conventional electrolyte additives often lead to complex mechanistic interpretations due to multifaceted effects.

Purpose of the Study:

• To introduce trimethylolethane (TME) as a novel electrolyte additive for AZIBs.
• To elucidate the mechanism of EDL-mediated anode stabilization.
• To demonstrate the performance enhancement of AZIBs using TME.

Main Methods:

• Adsorption studies of TME on zinc anode surfaces.
• Analysis of Zn2+ solvation structure and EDL modification.
• Electrochemical testing of Zn||Zn symmetric cells with TME additive.

Main Results:

• TME selectively modifies the EDL without altering Zn2+ solvation.
• TME promotes uniform Zn2+ distribution and suppresses parasitic reactions by forming a water-deficient interface.
• TME increases zinc ion nucleation overpotential, leading to dendrite-free zinc deposition.
• Zn||Zn symmetric cells with TME achieved a cycle life of 1495 hours at 1 mA cm-2.

Conclusions:

• TME serves as an effective additive for stabilizing zinc anodes in AZIBs.
• The study establishes a new paradigm in EDL-oriented electrolyte engineering.
• TME offers critical insights for designing high-performance AZIBs.