Surface Engineering for Ultrathin Metal Anodes Enabling High-Performance Zn-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Zinc-ion batteries (ZIBs) are promising for grid storage due to low cost and high safety.
• Controlling metal anode surface orientation is crucial for ZIB reversibility and stability.

Purpose of the Study:

• To develop a facile method for controlling Zn metal anode surface orientation.
• To create stable, ultrathin Zn anodes for enhanced ZIB performance.

Main Methods:

• Electrodeposition with electrolyte additives (dimethyl sulfoxide) in ZnSO4 aqueous electrolyte.
• Surface characterization using Scanning Electron Microscopy (SEM), Raman, X-ray Photoelectron Spectroscopy (XPS), and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS).
• Electrochemical testing in half and full cells (Zn||V2O5), including in situ optical observations and Density Functional Theory (DFT) calculations.

Main Results:

• An ultrathin (down to 2 μm) (101)-inclined Zn metal anode with flat, terrace-like surfaces was successfully fabricated.
• DFT calculations confirmed that DMSO and H2O adsorption on the Zn-(101) surface lowers interface energy, driving surface preference.
• The (101)-inclined anode exhibited excellent cycling stability (>200 h) with low overpotential (<50 mV) in half cells.
• Zn||V2O5 full cells with the 5 μm (101)-inclined anode showed superior performance (>170 mAh/g after 300 cycles) compared to commercial Zn foil.

Conclusions:

• Controlling Zn anode surface crystallographic orientation via electrolyte additives is an effective strategy for achieving stable ultrathin anodes.
• The (101)-inclined Zn anode demonstrates significant potential for high-performance and durable zinc-ion batteries.
• This approach offers a new direction for designing advanced anode materials for grid-scale energy storage.