Emerging Nitroso/Hydroxylamine Redox Chemistry for High-Performance Organic Cathodes in Aqueous Proton Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Organic cathode materials are promising for sustainable aqueous proton batteries.
• Key challenges include achieving high voltage, low solubility, and high capacity simultaneously.

Purpose of the Study:

• To introduce a novel biomimetic redox pair (nitroso/hydroxylamine) for energy storage.
• To design and synthesize a high-performance organic cathode material based on this redox pair.

Main Methods:

• Synthesis and characterization of 1-(hydroxyamino)anthracene-9,10-dione (NHOH-A).
• Electrochemical testing of NHOH-A as a cathode material with a Zn anode.
• Construction and evaluation of an all-organic proton battery using NHOH-A and an alloxazine anode.

Main Results:

• NHOH-A exhibits a reversible two-electron redox process with strong hydrogen bonding and extended π-conjugation.
• NHOH-A demonstrates a high discharge voltage (1.15 V), excellent capacity (224 mAh g⁻¹), and remarkable cyclability (>13,000 cycles) vs. Zn.
• The all-organic proton battery achieves 164 mAh g⁻¹ at 100 C and an energy density of 125 Wh kg⁻¹.

Conclusions:

• The nitroso/hydroxylamine redox chemistry is validated as a viable platform for organic cathodes.
• NHOH-A represents a significant advancement in organic cathode materials for aqueous proton batteries.
• This work opens new avenues for developing high-performance, sustainable organic energy storage systems.