Fully dry-processed electrodes for highly reversible aqueous zinc powder-based batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc-ion batteries offer promise for grid-scale storage but are hindered by low energy density due to high negative-to-positive (N/P) ratios.
• Zinc powder anodes can reduce N/P ratios but suffer from parasitic reactions and short lifespans caused by their high surface area.

Purpose of the Study:

• To develop a high-loading, reversible zinc powder anode for aqueous zinc-ion batteries.
• To enhance energy density and cycle life by mitigating parasitic reactions and zinc corrosion.

Main Methods:

• A dry-processing technique was employed to create a zinc powder anode with a homogeneous distribution of a sodium phosphate solid-electrolyte interphase (SEI) precursor.
• The anode was coupled with dry-processed cathodes to create a fully dry-processed aqueous zinc battery.
• Performance was evaluated using pouch cells, focusing on capacity retention and cycling stability at low N/P ratios.

Main Results:

• The dry-processed anode spontaneously formed a zinc phosphate-based SEI upon electrolyte contact, effectively suppressing hydrogen evolution and zinc corrosion.
• The fully dry-processed aqueous zinc battery achieved 88.8% capacity retention after 530 cycles at an N/P ratio of approximately 3.
• The system demonstrated superior performance compared to previous zinc powder systems, especially at significantly higher cathode loadings (90 mg cm^-2).

Conclusions:

• The developed dry-processed zinc powder anode provides a scalable solution for high-energy-density aqueous zinc batteries.
• This approach overcomes limitations of traditional zinc powder anodes, paving the way for practical grid-scale energy storage applications.