Ultra-Thin Hybrid Ion Exchange Interlayer for High Performance Aqueous Zn Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc metal batteries (AZMBs) face challenges with poor cycling stability and zinc dendrite formation.
• These issues limit the practical application and lifespan of AZMBs.

Purpose of the Study:

• To develop a novel hybrid interlayer for zinc anodes to improve AZMB performance.
• To address the limitations of cycling stability and dendritic growth in Zn anodes.

Main Methods:

• Fabrication of an ultra-thin hybrid interlayer using sulfonated poly(ether ether ketone) (SPEEK) and fluorinated carbon dots (FCDs).
• Characterization of the interlayer's properties and its effect on electrolyte solvation and ion transport.
• In situ formation of a stable ZnF2-rich solid electrolyte interphase (SEI).
• Testing of Zn||Zn symmetric cells and Zn||V2O5 full cells with the modified electrodes.

Main Results:

• The SPEEK/FCD interlayer effectively regulates electrolyte solvation and promotes ion transport.
• It induces the formation of a stable ZnF2-rich SEI, accommodating volume changes during cycling.
• Zn||Zn symmetric cells demonstrated an ultralong lifespan exceeding 5500 hours.
• Zn||V2O5 full cells retained 89.8% capacity after 1000 cycles, significantly outperforming bare Zn electrodes.

Conclusions:

• The SPEEK/FCD hybrid interlayer significantly enhances the cycling stability and performance of AZMBs.
• This approach offers a promising strategy for developing next-generation aqueous batteries.
• The scalable fabrication method provides a valuable reference for improving other aqueous battery systems.