Aqueous Zinc-Organoiodine Battery with High Kinetics and Dense Cathodes

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Aqueous zinc-ion batteries (AZIBs) are promising for safe, sustainable energy storage.
• Organic compounds in AZIBs face challenges like low conductivity and intermediate solubility.

Purpose of the Study:

• To design a charge-transfer complex to overcome limitations of organic materials in AZIBs.
• To enhance the performance and stability of AZIBs for practical applications.

Main Methods:

• Formation of a charge-transfer complex between phenazine (PNZ) and iodine (I2).
• Fabrication of dense cathodes with high mass loading (approx. 60 mg·cm-2).
• Electrochemical testing including cycling stability at high current densities.

Main Results:

• PNZ-I2 complex shows significantly improved conductivity and fast reaction kinetics.
• N-H···I hydrogen bonds minimize intermediate solubility, enhancing cycling stability.
• High capacity retention (92% after 4500 cycles at 3.0 A·g-1) and stable performance in a 1.1 Ah AZIB (70% after 700 cycles).

Conclusions:

• The PNZ-I2 complex offers a viable strategy for high-performance AZIBs.
• Recyclable and low-cost PNZ-I2 contributes to renewable energy and energy storage technologies.