Highly Potent and Low-Volume Concentration Additives for Durable Aqueous Zinc Batteries: Machine Learning-Enabled...

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc batteries offer high energy density but suffer from zinc anode corrosion and dendrite formation, limiting cycle life.
• Developing effective electrolyte additives at low concentrations is crucial for practical zinc battery applications.

Purpose of the Study:

• To identify potent electrolyte additives for aqueous zinc batteries that function at low concentrations.
• To investigate the mechanism by which additives improve zinc anode stability and battery performance.

Main Methods:

• Screening of alkanol and alkanediol chemistries as electrolyte additives.
• Characterization of the solid-electrolyte interphase (SEI) formation and interfacial properties.
• Electrochemical testing of zinc anodes and full cells, including cycling performance and Coulombic efficiency.
• Machine learning analysis to correlate additive performance with physicochemical properties.

Main Results:

• 1,2-butanediol and pentanediol identified as highly effective additives at 1 volume%.
• Additives promote dynamic SEI formation via interfacial filming, mitigating corrosion and dendrites.
• Achieved 5-20x enhancement in zinc cyclability with up to 99.9% Coulombic efficiency.
• Improved full-cell performance observed, even at elevated temperatures.

Conclusions:

• Low-volume concentration additives (1,2-butanediol, pentanediol) can significantly enhance aqueous zinc battery stability and cycle life.
• The mechanism involves forming a protective, dynamic SEI layer on the zinc anode.
• Machine learning approach aids in rational discovery of future electrolyte additives for energy storage.