Aqueous Alkaline Zinc-Iodine Battery with Two-Electron Transfer

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Alkaline zinc batteries are crucial for energy storage but are limited by a lack of suitable cathode materials.
• Iodine is a promising cathode candidate due to its versatile valence states and redox potential.
• Existing alkaline iodine chemistry faces challenges with alkali-unadapted elements and unstable reaction products.

Purpose of the Study:

• To formulate and evaluate a novel aqueous alkaline zinc-iodine battery system.
• To overcome the limitations of traditional iodine cathodes in alkaline environments.
• To explore new cathode materials for advanced alkaline batteries.

Main Methods:

• Development of an organic iodized salt cathode.
• Utilisation of a chloride ion-manipulated electrolyte.
• Two-electron transfer redox reaction investigation.
• Theoretical and experimental characterization of battery performance.

Main Results:

• Achieved a high discharge plateau of 1.68 V.
• Obtained a specific capacity of 385 mA h g⁻¹.
• Reached an exceptional energy density of 577 W h kg⁻¹.
• Confirmed the redox chemistry between alkaline electrolyte and iodine species.

Conclusions:

• The developed organic iodized salt cathode enables efficient alkaline zinc-iodine battery operation.
• This system offers superior energy density compared to existing counterparts.
• The novel iodine chemistry in alkaline media significantly expands the scope of cathode materials for alkaline batteries.