Advancing Flexible Zinc Air Battery: Exploring Non‐Noble Metal Oxides for Enhanced Electronic Structure Modulation in Scalable Engineering Design

Why It Matters

The breakthrough provides a low‑cost, durable bifunctional catalyst for scalable zinc‑air batteries, accelerating the commercialization of flexible, wearable power sources.

Key Takeaways

• Scalable reflux-calcination yields flower-like Fe–Mo oxides.
• FeMoO-III overpotential 240 mV at 10 mA cm⁻².
• ORR half-wave potential reaches 0.86 V.
• Battery delivers 1.51 V open-circuit voltage.
• Flexible cell operates 56 h at 5 mA cm⁻².

Pulse Analysis

Zinc‑air batteries have long promised high energy density at low cost, yet their widespread adoption hinges on bifunctional catalysts that can drive both the oxygen evolution reaction (OER) during charging and the oxygen reduction reaction (ORR) during discharge. Conventional noble‑metal catalysts such as Pt and IrO₂ deliver excellent activity but are prohibitively expensive and scarce for large‑scale or wearable applications. Recent research therefore focuses on earth‑abundant transition‑metal oxides, seeking to balance performance, durability, and manufacturability.

In this context, the Fe–Mo oxide series introduced through a reflux‑calcination route represents a strategic advance. By engineering Fe‑O‑Mo linkages, the electronic structure of the catalyst is finely tuned, lowering adsorption energy barriers and accelerating charge‑transfer kinetics. The Fe0.25Mo0.75O composition (FeMoO‑III) achieves a remarkable OER overpotential of just 240 mV at 10 mA cm⁻² and an ORR half‑wave potential of 0.86 V, while maintaining stability for over 200 hours at high current densities. Importantly, the synthesis is scalable, producing uniform flower‑like nanostructures that facilitate mass transport and electrolyte access.

The practical implications are significant for flexible and wearable electronics. When incorporated into a quasi‑solid‑state zinc‑air cell, FeMoO‑III sustains a 1.51 V open‑circuit voltage and operates continuously for more than 56 hours at a modest 5 mA cm⁻², demonstrating resilience under mechanical deformation. This performance bridges the gap between laboratory prototypes and market‑ready power modules, positioning non‑noble metal oxides as viable candidates for next‑generation, cost‑effective energy storage solutions. Future work will likely explore further compositional tuning and integration with advanced electrolytes to push power density and cycle life even higher.