Anionic Metal-Organic Framework as an Ultrafast Single-Ion Conductor for Exceptional Performance Rechargeable Zinc...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Anionic metal-organic frameworks (MOFs) are explored as single-ion conductive electrolytes for quasi-solid-state batteries.
• Developing high-performance solid electrolytes is crucial for safer and more efficient energy storage devices.

Purpose of the Study:

• To propose and synthesize a novel anionic MOF as a single Zn²⁺ conductor.
• To evaluate its performance as an electrolyte in quasi-solid-state zinc-ion batteries (ZIBs).

Main Methods:

• Synthesis of an anionic MOF via reaction of functionalized tetraphenylborate with a Zr₆-oxo cluster.
• Characterization of ionic conductivity, Zn²⁺ transference number, and activation energy of the MOF.
• Fabrication and electrochemical testing of quasi-solid-state ZIBs utilizing the synthesized MOF and NH₄V₄O₁₀ cathode.

Main Results:

• The anionic MOF exhibited outstanding ionic conductivity (7.9 mS cm^-1 at 120 °C) and a high Zn²⁺ transference number (0.90).
• The quasi-solid-state ZIB demonstrated a high capacity (497 mAh g^-1 at 0.3 A g^-1) and excellent rate performance.
• The battery maintained 100% capacity and Coulombic efficiency after 2500 cycles, even at low temperatures and high current densities.

Conclusions:

• The developed anionic MOF is a promising single Zn²⁺ conductor for high-performance quasi-solid-state ZIBs.
• This research opens new avenues for designing anionic porous materials as advanced solid electrolytes for various secondary batteries.