Prospects of Alkali Metal–Se Batteries and Beyond: From Redox Mechanisms to Electrode Design

Selenium-based alkali metal systems offer significant potential for surpassing commercial Li-ion systems in volumetric energy density (3,253 vs 1,000 mAh cm−3). However, challenges remain in electrode design, solid electrolyte interface stability, and mitigating active material dissolution. This review explores redox mechanisms, electrode architectures, and electrolyte strategies for enhancing performance, with a focus on Li, Na, K anodes and beyond. Advances in computational and experimental studies are discussed, highlighting key issues and future research directions to address scalability and improve stability, making Se-based batteries promising candidates for sustainable energy storage.