A multifunctional quasi-solid-state polymer electrolyte with highly selective ion highways for practical zinc ion...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Aqueous zinc ion batteries face challenges with uncontrolled dendrite growth and parasitic reactions on zinc anodes, hindering their practical application.
• Developing stable and efficient zinc anodes is crucial for advancing rechargeable aqueous batteries.

Purpose of the Study:

• To design a quasi-solid-state polymer electrolyte with selective ion transport channels.
• To engineer a Zn-Mg-Si medium-entropy alloy for improved zinc deposition kinetics.
• To enhance the long-term cycling stability and performance of aqueous zinc ion batteries.

Main Methods:

• Molecular crosslinking of sodium polyacrylate, lithium magnesium silicate, and cellulose nanofiber to create a polymer electrolyte.
• In-situ formation of a Zn-Mg-Si medium-entropy alloy on the zinc anode.
• Testing of Zn anodes and Zn||V2O5 batteries for Coulombic efficiency, cycling stability, and capacity.

Main Results:

• The polymer electrolyte facilitated selective Zn2+ transport and modulated desolvation.
• The Zn-Mg-Si alloy promoted homogeneous zinc nucleation and deposition, suppressing dendrites.
• Zn anodes achieved 99.7% average Coulombic efficiency over 2400 cycles and 600h cycling at 85.6% depth of discharge.
• The Zn||V2O5 battery demonstrated stable cycling with a capacity of 1.13 Ah at industrial loading.

Conclusions:

• The developed quasi-solid-state polymer electrolyte and alloy anode effectively address key limitations in aqueous zinc ion batteries.
• This approach significantly improves the cycling stability, efficiency, and overall performance of zinc anodes.
• The findings pave the way for the large-scale implementation of high-performance aqueous zinc ion batteries.