Dienoic-Acid Coupling Effect Induced Hierarchical Interface for High-Performance Zinc Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Designing solid electrolyte interphase (SEI) layers for zinc anodes faces challenges in understanding structure-function relationships and lacks design criteria.
• Suppressing hydrogen evolution reaction (HER) and zinc dendrite growth is crucial for high-performance zinc metal batteries.

Purpose of the Study:

• To propose a novel dienoic-acid coupling effect for in-situ construction of hierarchical SEI layers (HSL).
• To investigate the structure-function relationship of organic-acid molecules in forming HSL.
• To enhance the stability and performance of zinc metal batteries.

Main Methods:

• Structural screening of organic-acid molecules to identify suitable candidates for HSL formation.
• Utilizing the electron-withdrawing ability of dual carboxyl and metastable double bonds in organic acids.
• Investigating the role of HSL in regulating the interfacial water environment and ion diffusion.

Main Results:

• The dienoic-acid coupling effect successfully formed a hierarchical SEI layer (HSL) via chemical and electrochemical reactions.
• HSL effectively regulated the interfacial water, facilitated desolvation kinetics, and promoted uniform Zn2+ diffusion.
• Zinc anodes with HSL achieved 99.8% coulombic efficiency over 2400 cycles and 3800 h stability.
• Zinc-iodine batteries with HSL demonstrated 15,000 cycles and powered portable instruments.

Conclusions:

• The dienoic-acid coupling effect provides a rational design strategy for advanced SEI layers.
• HSL formation significantly suppresses HER and dendrite growth, improving zinc anode performance.
• This approach opens new avenues for designing high-performance interfaces using trace electrolyte additives for zinc metal batteries.