Light-driven photocathodes in Li/Zn-O2 (air) batteries: An analytical review, technological breakthroughs and future challenges
Md Iftekher Hossain, Foysal Kabir Tareq, Souman Rudra
Abstract
The rapid advancement of renewable energy technologies has intensified the demand for high-performance energy storage systems. Metal-O 2 (air) batteries, specifically Li-O 2 (air) and Zn-O 2 (air) variants, present exceptional theoretical energy densities , positioning them as promising candidates for next-generation storage solutions. However, significant challenges remain in optimizing the oxygen reduction and evolution reactions (ORR/OER), critical for achieving high efficiency and stability. Recent developments in light-assisted metal-O 2 (air) battery designs leverage photonic energy to enhance oxygen reduction and evolution reactions, offering reduced charge voltages, improved round-trip efficiencies, and extended lifetimes. This review critically evaluates the breakthroughs and limitations in photo-assisted Li/Zn-O 2 (air) battery technologies, with a focus on novel photocathode materials, including advanced semiconductors, heterojunction configurations, and nanostructured catalysts. We systematically highlight the key properties of these photocathode materials, evaluating their photon-utilization efficiency, charge separation capabilities, recombination rates, charging/discharging profiles, efficient decomposition of discharge products and stability under operational conditions. Emphasis is placed on advanced strategies to enhance light absorption , aiming to optimize photocatalytic efficiency, electronic properties, and catalytic stability, thereby overcoming current performance barriers. By providing a comprehensive analysis of the current landscape and emerging trends, this review aims to chart a path forward for the development of more robust, efficient, and sustainable light-assisted Li/Zn-O 2 (air) batteries, highlighting the essential role of innovative photocathode materials in achieving next-generation energy storage solutions.