Semiconductor for oxygen electrocatalysis in photo-assisted rechargeable zinc-air batteries: Principles, advances, and opportunities

Zinc-air batteries (ZABs) are regarded as the most promising next-generation energy storage device due to their high theoretical energy density, lower price, safety, portability and rechargeability property. However, the poor electrochemical performance of the cathode reaction (oxygen reduction reaction and oxygen evolution reaction) leads to high polarization, low round-trip efficiencies (less than 65%), and non-durable circulation that limit their commercial application. Utilizing efficient and economical solar light to expedite sluggish cathode reaction kinetics has progressively become a feasible strategy to address this issue. Based on rapid development and emergent studies, this review focus on the critical issues and main challenges of photocathode on oxygen electrocatalysis in rechargeable ZABs, especially the semiconductor properties, including light utilization efficiency, modulation of photogenerated carriers and photothermal effects on battery performance. Additionally, the design principles, as well as the current challenges and prospects are also critically evaluated.