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Researchers from Chinese Donghua University have reported a major advance in zinc air battery technology, addressing long standing stability problems that have limited the chemistry’s real world use and potentially opening a path toward cheaper and safer energy storage systems.
Zinc air batteries have attracted attention for decades because zinc is abundant, low cost, and non toxic. The batteries generate electricity through a reaction between zinc and oxygen drawn from the air, giving them a theoretical energy density comparable to lithium ion cells. In practice, however, their adoption has been constrained by poor durability, unstable air electrodes, and rapid performance degradation over repeated charge and discharge cycles.
The research introduces an exciting innovation by cleverly combining photoactivity and electrocatalysis into a single air-electrode design. The catalyst features graphitic carbon nitride nanosheets paired with a self-supporting carbon nanofiber framework, which is enhanced by two types of cobalt active sites: cobalt nanoparticles wrapped in carbon nanotubes and atomically dispersed Co–N₄ moieties. This setup creates a type-II p–n heterojunction that encourages directional charge transfer when light hits it, as highlighted in the study.
When illuminated, the photogenerated electrons move toward the conductive carbon framework, driving the oxygen reduction reaction, while the holes help facilitate the oxygen evolution reaction on nearby sites. This clever spatial separation minimizes charge recombination and reduces the energy barriers for reactions. Electrochemical tests show an impressively low oxygen reaction overpotential gap of just 0.684 V under light, surpassing many leading bifunctional catalysts.
When put together in practical zinc–air batteries, this photo-enhanced system achieves a peak power density of 310 mW cm⁻² and keeps stable charge–discharge operations going for over 1,100 hours.
The development comes as energy storage becomes increasingly critical to global decarbonization efforts. Renewable sources such as wind and solar require large scale storage to balance intermittent generation, and lithium ion batteries, while effective, rely on costly and geopolitically sensitive materials like cobalt and nickel. Zinc air systems avoid many of these constraints and are inherently safer due to their aqueous, non flammable design.
Looking beyond just zinc–air batteries, the design principles we’ve explored here can also be applied to other types of metal–air batteries and photo-assisted electrochemical systems. More generally, this research points to an exciting opportunity for directly integrating solar energy into electrochemical energy storage. This could really help close the gap between harvesting renewable energy and using it efficiently, as noted by the researchers.
If successful, the advance could help diversify global battery supply chains and reshape how energy is stored in a rapidly electrifying world.
