Crystallographic microstructure engineering for artificial solid electrolyte interphases toward stable zinc electrode

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Dendrite growth in metal batteries limits lifespan, even with optimized artificial solid electrolyte interphases (ASEIs).
• Current research focuses on chemical composition, overlooking the impact of ASEI crystallographic microstructure.

Purpose of the Study:

• To investigate the effect of crystallographic microstructure, specifically grain orientation and grain boundary density, on the performance of ZnS ASEI in aqueous Zn batteries.
• To identify the optimal microstructure for enhanced battery lifespan and stability.

Main Methods:

• Case study using ZnS ASEI in aqueous Zn batteries.
• Analysis of grain orientation and grain boundary density effects on Zn negative electrode performance.
• Electrochemical testing to evaluate cycling stability and Coulombic efficiency.

Main Results:

• An optimal microstructure featuring predominant in-plane (111) orientation and a grain boundary density of ~55 μm/μm² was identified.
• This optimal microstructure led to an 18-fold lifespan extension and over 3400 cycles with 99.92% Coulombic efficiency at 5 mA cm⁻².
• (111) orientation enhanced electrochemical kinetics and mechanical strength, while grain boundary density presented a trade-off between kinetics and mechanical stability.

Conclusions:

• Crystallographic microstructure engineering is an effective strategy for designing artificial solid electrolyte interphases (ASEIs).
• Optimizing ASEI microstructure offers a promising route to overcome dendrite growth limitations and extend metal battery lifespan.
• The findings demonstrate the critical role of microstructure in achieving high-performance and long-lasting batteries.