# Efficient and Scalable Electrochemical Energy Systems via Peroxide‐Mediated Redox Chemistry

## TL;DR

This paper explores a new electrochemical pathway using hydrogen peroxide to improve the efficiency and scalability of renewable energy systems like batteries and fuel cells.

## Contribution

The paper introduces a two-electron O2 redox pathway as a novel alternative to the conventional four-electron pathway for better energy efficiency.

## Key findings

- The two-electron O2 redox pathway enables faster kinetics and lower energy barriers compared to the four-electron pathway.
- Peroxide-mediated strategies improve round-trip energy efficiency in rechargeable zinc–air batteries.
- This approach supports scalable hydrogen production without the need for external storage or transportation.

## Abstract

The transition to renewable energy demands cost‐effective and environmentally sustainable technologies. Electrochemical redox reactions, particularly the oxygen evolution reaction and the oxygen reduction reaction, are central to energy conversion and storage systems such as metal–air batteries, electrolyzers, and fuel cells. However, the conventional four‐electron O2 redox pathway suffers from sluggish kinetics and large overpotentials, limiting both efficiency and commercial viability. An emerging alternative is the two‐electron O2 redox pathway based on reversible O2/H2O2 conversion. This route offers faster kinetics, lower energy barriers, and a simpler reaction mechanism involving a single intermediate—hydrogen peroxide. This perspective reviews recent progress in two‐electron O2 redox chemistry, with an emphasis on its integration into metal–air batteries and water‐splitting systems. Underlying mechanisms, materials challenges, and innovations in catalyst and electrode design that enable efficient, reversible O2/H2O2 cycling are examined. Peroxide‐mediated strategies offer a promising direction for overcoming the limitations of the four‐electron pathway and advancing scalable, high‐efficiency electrochemical energy technologies.

We outline reaction mechanisms and catalyst strategies that enable efficient, reversible O2 ⇌ HO2
– chemistry. Peroxide‐mediated pathways offer an alternative to the conventional 4e–/O2 route, improving round‐trip energy efficiency in rechargeable zinc–air batteries and supporting scalable hydrogen production without external storage or transportation infrastructure. Key challenges and future opportunities for next‐generation electrochemical energy technologies are also outlined.