Laser Assisted Rapid Prototyping of In-Plane, Flexible, Rechargeable Aqueous Zn-S Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-melting-point polymers like polyimide can be patterned using CO2 lasers for microelectronics and energy storage.
• Laser-induced graphene (LIG) offers a versatile platform for fabricating advanced electrode materials.

Purpose of the Study:

• To demonstrate the ultrafast fabrication of a binder-free, flexible, in-plane zinc-sulfur battery.
• To develop laser-induced graphene supported interdigitated electrodes for zinc and sulfur.
• To address capacity fading issues in zinc-sulfur batteries.

Main Methods:

• Utilized CO2 laser-assisted graphitization of polyimide to create LIG.
• Employed a sublimation-transport-desublimation process to load elemental sulfur onto LIG, forming S@LIG electrodes.
• Investigated sulfur species using ex situ XRD/XPS analysis.
• Mitigated parasitic reactions using a gel polymer electrolyte.

Main Results:

• Achieved binder-free, high-sulfur-content S@LIG electrodes with ~58% sulfur content.
• Identified shuttling soluble sulfates as a cause of capacity fading in aqueous electrolytes.
• Demonstrated a semi-solid-state flexible in-plane Zn-S prototype cell.
• The prototype cell delivered a capacity of 59 µAh cm⁻² sustained over 80 cycles at 25 µA/cm².

Conclusions:

• Ultrafast laser-induced fabrication is effective for creating binder-free flexible Zn-S batteries.
• Gel polymer electrolytes successfully mitigate parasitic reactions and improve cycle life.
• The developed Zn-S battery shows promising electrochemical performance for flexible energy storage applications.