Bifunctional Electrocatalysis in Zinc-Air Battery Systems

Bifunctional electrocatalysis in zinc-air battery systems centres on catalysts capable of mediating the oxygen reduction reaction (ORR) during discharge and the oxygen evolution reaction (OER) during charge. Zinc-air batteries offer high theoretical energy density, safety and cost advantages by utilising ambient oxygen as the cathode reactant and zinc metal as the anode. However, sluggish kinetics of the four-electron ORR and OER, alongside catalyst degradation and mass-transport limitations, have hindered widespread adoption. Recent advances in catalyst design—spanning transition metal oxides, heteroatom-doped carbons, metal–organic frameworks (MOFs) and single-atom catalysts—have sought to reconcile activity, stability and scalability. Strategies such as tuning electronic structure, engineering porous architectures and exploiting synergetic interactions between metal–support motifs have yielded catalysts with reduced overpotentials, narrowed charge–discharge voltage gaps and extended cycle lifetimes, paving the way for practical, durable and flexible zinc-air devices with applications in grid storage, portable electronics and wearable power sources.

Research from Nature Portfolio

Ligand tailoring within cobalt–zinc heterometal imidazole frameworks has been shown to finely tune metal d-orbital occupancy, lowering the energy barriers for oxygen-intermediate adsorption and enhancing both ORR and OER kinetics. These frameworks exhibited a narrow discharge–charge voltage gap of approximately 0.8 V and sustained cyclability beyond 1 250 hours at 15 mA cm⁻² under alkaline conditions. In complementary work, hierarchically assembled Co₃O₄/MnO₂ nanohybrids on carbon nanotubes capitalised on hybrid-interface synergy to deliver a peak power density exceeding 450 mW cm⁻² and demonstrated stable cycling with minimal potential degradation, outperforming state-of-the-art non-precious bifunctional catalysts in both liquid and solid-state zinc-air configurations.

Bifunctional Electrocatalysis in Zinc-Air Battery Systems publication trend

The graph below shows the total number of articles in bifunctional electrocatalysis in zinc-air battery systems across all publications each year (not limited to Nature Index journals).

Technical terms

Bifunctional electrocatalyst: A catalyst engineered to catalyse both oxygen reduction (ORR) and oxygen evolution reactions (OER) in rechargeable metal-air batteries.

Oxygen reduction reaction (ORR): The electrochemical process by which oxygen molecules gain electrons during the discharge of a zinc-air battery.

Oxygen evolution reaction (OER): The electrochemical process by which oxygen molecules are regenerated during the charging of a zinc-air battery.

Metal–organic framework (MOF): A porous crystalline material composed of metal ions coordinated to organic ligands, used as a template or precursor for catalyst synthesis.

Single-atom catalyst: A catalyst in which isolated metal atoms are dispersed on a support to maximise atom utilisation and catalytic activity.

References

1. Aerophilic Triphase Interface Tuned by Carbon Dots Driving Durable and Flexible Rechargeable Zn-Air Batteries. Nano-Micro Letters (2023).
2. Ultralong nitrogen/sulfur Co‐doped carbon nano‐hollow‐sphere chains with encapsulated cobalt nanoparticles for highly efficient oxygen electrocatalysis. Carbon Energy (2023).
3. d-Orbital steered active sites through ligand editing on heterometal imidazole frameworks for rechargeable zinc-air battery. Nature Communications (2020).
4. Self-assembly formation of Bi-functional Co3O4/MnO2-CNTs hybrid catalysts for achieving both high energy/power density and cyclic ability of rechargeable zinc-air battery. Scientific Reports (2016).
5. Carbon‐Nanotube‐Bridging Strategy for Integrating Single Fe Atoms and NiCo Nanoparticles in a Bifunctional Oxygen Electrocatalyst toward High‐Efficiency and Long‐Life Rechargeable Zinc–Air Batteries. Advanced Energy Materials (2022).