Effects of current density on Zn reversibility

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc batteries (AZBs) are promising for stationary energy storage.
• High current density (j) is crucial for rapid charging/discharging in AZBs.
• Existing literature shows conflicting results on the effect of j on zinc anode reversibility.

Purpose of the Study:

• To investigate the inconsistent experimental findings regarding the impact of current density on zinc reversibility in AZBs.
• To elucidate the fundamental mechanisms governing zinc electrodeposition under varying current densities.
• To provide a clear perspective on the relationship between current density and zinc anode performance.

Main Methods:

• Analysis of zinc electrodeposition fundamentals.
• Application of nucleation-growth models and theories related to current density.
• In-depth discussion of thermodynamic and kinetic factors influencing zinc plating/stripping.

Main Results:

• The study proposes a volcano-shaped pattern for zinc plating/stripping reversibility as current density increases.
• Identifies dual and contradictory roles of high current density in thermodynamics and interfacial kinetics.
• Offers insights into accurate interpretation of experimental data.

Conclusions:

• The relationship between current density and zinc reversibility in AZBs is complex and follows a volcano-shaped trend.
• Understanding these fundamental principles is key to optimizing AZB performance.
• This work provides a foundation for developing advanced high-power aqueous zinc batteries.