Benzidine Derivatives as Electroactive Materials for Aqueous Organic Redox Flow Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Organic Chemistry

Background:

• Organic redox flow batteries require stable, water-soluble electroactive molecules.
• Benzidine derivatives are explored for their potential in multielectron transfer processes.

Purpose of the Study:

• To evaluate benzidine derivatives as electroactive materials for organic redox flow batteries.
• To synthesize, characterize, and theoretically study a specific benzidine derivative for its electrochemical properties.

Main Methods:

• Synthesis and electrochemical characterization of sodium 4-diphenylamine sulfonate dimer.
• Theoretical calculation and experimental calibration of Pourbaix diagrams for various benzidine derivatives.
• Screening of derivatives for suitable redox potentials and pH stability.

Main Results:

• The sodium 4-diphenylamine sulfonate dimer exhibits bielectronic and single-electron transfer processes across different pH ranges.
• Calculated Pourbaix diagrams, calibrated with experimental data, guided the selection of promising candidates.
• Selected benzidine derivatives demonstrated potential for generating theoretical cell voltages up to 0.68 V.

Conclusions:

• Benzidine derivatives are viable candidates for electroactive materials in full-organic redox flow batteries.
• Tuning substitution patterns and functional groups optimizes performance for specific pH conditions.
• These molecules offer a pathway towards more sustainable and efficient organic redox flow battery technologies.