Direct solar energy conversion on zinc-air battery

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Traditional energy storage systems require separate solar cells for charging.
• Developing integrated devices for direct solar energy conversion and storage is crucial for future energy solutions.

Purpose of the Study:

• To demonstrate a novel solar energy convertible zinc-air battery (SZAB) that directly converts and stores solar energy.
• To utilize a multifunctional electrode for enhanced photoresponsive electrocatalysis.

Main Methods:

• Fabrication of a multifunctional electrode using nitrogen-substituted graphdiyne (N-GDY).
• Characterization of the electrode's photoresponsive bifunctional electrocatalytic properties.
• Performance evaluation of the SZAB under illumination, including charge voltage, energy efficiency, and power conversion efficiency.
• Density functional theory (DFT) calculations to elucidate reaction mechanisms.

Main Results:

• The N-GDY electrode functions as a photoresponsive bifunctional electrocatalyst, enabling sunlight-promoted charging.
• The SZAB demonstrated a lowered charge voltage under illumination, achieving 90.4% energy efficiency and 30.3% electric energy saving.
• A power conversion efficiency of 1.02% was achieved.
• DFT calculations revealed that photoexcitation promotes oxygen evolution reaction kinetics by altering electronic structure and facilitating intermediate formation.

Conclusions:

• The developed SZAB offers a direct pathway for charging batteries using solar energy without external solar cells.
• This work provides conceptual and experimental validation for integrated solar energy conversion and storage devices.
• The findings pave the way for manufacturing future energy devices with enhanced efficiency and simplified design.