Anion-Anchored Polymer-in-Salt Solid Electrolyte for High-Performance Zinc Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Rechargeable zinc batteries (ZBs) face challenges with aqueous electrolytes, including dendrite formation and limited stability.
• Solid polymer electrolytes (SPEs) offer potential solutions but struggle with low ionic conductivity, poor mechanical strength, and inefficient ion transport.

Purpose of the Study:

• To design and synthesize a novel polymer-in-salt solid electrolyte (PISSE) for advanced ZBs.
• To enhance ionic conductivity, mechanical properties, and Zn2+ transference number while suppressing Zn dendrites.

Main Methods:

• Fabrication of a PISSE using polyacrylonitrile (PAN), zinc chloride (ZnCl2), and niobium pentoxide with oxygen vacancies (Nb2O5-x).
• Characterization of ionic conductivity, mechanical properties, Zn2+ transference number, and interfacial stability.
• Electrochemical testing of ZBs utilizing the developed PISSE under various conditions.

Main Results:

• The PISSE achieved high ionic conductivity due to the PAN matrix and high ZnCl2 concentration.
• Incorporation of Nb2O5-x improved Zn2+ desolvation, mechanical strength, and interfacial stability, yielding a Zn2+ transference number of ~0.93.
• The optimized PISSE demonstrated exceptional cycling stability, wide temperature range operation (-40°C to 60°C), and flexibility.

Conclusions:

• The novel PISSE effectively addresses key limitations in ZBs, offering a promising solid-state electrolyte solution.
• The material design provides a pathway for developing high-performance, safe, and durable rechargeable zinc batteries.
• This work highlights the potential of PISSEs for diverse electrochemical energy storage applications.