Strain-Modulated Deposition Mechanism on a Flexible Zinc Anode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Flexible aqueous zinc-ion batteries (AZIBs) offer high capacity, low cost, and safety, making them attractive for wearable electronics.
• However, zinc (Zn) dendrite formation and poor Zn anode flexibility limit their practical application in flexible devices.

Purpose of the Study:

• To develop a flexible substrate for AZIBs that enhances Zn anode stability and performance under mechanical strain.
• To investigate the electrochemical behavior and morphology of Zn anodes on a novel flexible substrate using an in situ strain system.

Main Methods:

• Fabrication of a flexible substrate by coating graphene onto polyethylene terephthalate-indium tin oxide (PET-ITO-G).
• Development of a quantitative in situ strain system to apply and control bending strains.
• Electrochemical testing (plating/stripping) and morphological analysis of Zn anodes under various strain conditions.

Main Results:

• The PET-ITO-G substrate demonstrated excellent flexibility and dendrite suppression capabilities.
• Stable Zn plating/stripping was achieved under static bending strain, attributed to the formation of densely packed Zn (101).
• A failure model for strain-modulated Zn deposition was proposed, highlighting surface cracks and distorted current distribution as key factors.

Conclusions:

• The developed flexible substrate significantly improves the stability and cycling life of Zn anodes in AZIBs under strain.
• Understanding strain-modulated deposition is crucial for designing robust flexible metal anodes.
• This work provides a systematic approach to study the impact of in situ strain on flexible battery performance.