Backside Coating for Stable Zn Anode with High Utilization Rate

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Stable zinc (Zn) anodes with high utilization rates are crucial for advancing Zn-ion batteries (ZIBs).
• Current ZIB technology faces challenges in achieving high specific and volumetric energy densities due to anode instability.
• Existing solutions often involve surface coatings, which have limitations.

Purpose of the Study:

• To develop a novel anode strategy for enhanced cycling stability in ZIBs.
• To investigate the impact of a backside coated layer on Zn anode performance.
• To improve Zn utilization and energy density for practical ZIB applications.

Main Methods:

• A zinc foil with a backside coated layer was fabricated and tested.
• Electrochemical cycling stability was evaluated under high depth of discharge.
• Performance was compared against bare Zn anodes and surface-coated Zn foils.
• A full cell utilizing the novel anode was assembled and tested.

Main Results:

• The backside coated Zn anode demonstrated significantly enhanced cycling stability.
• The coating effectively reduced stress concentration, improved heat diffusion, and facilitated electron transfer.
• Dendrite growth and structural damage were prevented, even at high Zn utilization (85.5%).
• The anode achieved stable cycling for 334 hours, outperforming previous methods.
• A full cell exhibited stable performance with 69.4% Zn utilization and high energy densities (155.8 Wh kg⁻¹ / 178 Wh L⁻¹).

Conclusions:

• A backside coated Zn anode offers a superior approach to enhancing ZIB stability and performance.
• This method effectively addresses dendrite formation and structural degradation at high Zn utilization.
• The developed anode technology paves the way for practical, high-energy-density ZIBs.