Entropy‐Engineered Layered Double Hydroxide Derived High‐Entropy Alloy Cathodes for Zinc–Air Batteries Under High Depth‐of‐Discharge

Why It Matters

These results demonstrate that entropy‑engineered HEA catalysts can overcome the durability and efficiency limits of current zinc‑air battery cathodes, enabling longer‑lasting, high‑energy storage for grid and portable applications.

Key Takeaways

• High-entropy alloy derived from layered double hydroxide.
• Uniform MnFeCoNiCu HEA on N‑doped carbon nanotubes.
• OER overpotential 475 mV, ORR half‑wave 0.81 V.
• Specific capacity 801 mAh g⁻¹ Zn, power density 186 mW cm⁻².
• Stable over 3325 cycles at high depth‑of‑discharge.

Pulse Analysis

Zinc‑air batteries (ZABs) are gaining traction as a low‑cost, high‑energy alternative to lithium‑ion systems, but their commercial viability hinges on cathodes that can efficiently catalyze both oxygen reduction (ORR) and oxygen evolution (OER) over many charge‑discharge cycles. Conventional catalysts often suffer from rapid degradation under deep‑discharge conditions, limiting cycle life and power density. Entropy engineering—mixing multiple transition metals into a single alloy lattice—offers a pathway to create robust active sites with tunable electronic structures, addressing these long‑standing challenges.

The reported MnFeCoNiCu high‑entropy alloy (HEA) leverages a layered double hydroxide (LDH) precursor that, after dicyandiamide‑assisted pyrolysis, simultaneously grows nitrogen‑doped carbon nanotubes and embeds uniformly dispersed alloy nanoparticles. This synthesis yields a face‑centered cubic phase with pronounced lattice distortion and strong metal‑carbon coupling, which together enhance electrical conductivity and provide abundant catalytic sites. The resulting bifunctional performance—475 mV OER overpotential at 10 mA cm⁻² and a 0.81 V ORR half‑wave potential—translates into a ΔE of 0.89 V, rivaling the best reported non‑precious catalysts.

Beyond laboratory metrics, the HEA‑based ZAB achieves a near‑theoretical specific capacity of 801 mAh g⁻¹ Zn and a peak power density of 186 mW cm⁻², while sustaining over 3,300 high‑depth‑of‑discharge cycles. Flexible gel‑polymer configurations retain these figures, opening avenues for wearable electronics and grid‑scale storage where mechanical resilience is critical. As the energy market seeks scalable, durable solutions, entropy‑engineered HEA cathodes could become a cornerstone technology, prompting further investment in multi‑metal catalyst design and large‑scale manufacturing processes.