Recent Advances in Understanding of the Singlet Oxygen in Energy Storage and Conversion

Singlet oxygen (term symbol ¹Δ_g, hereafter ¹O₂), a reactive oxygen species, has recently attracted increasing interest in the field of rechargeable batteries and electrocatalysis and photocatalysis. These sustainable energy conversion and storage technologies are of vital significance to replace fossil fuels and promote carbon neutrality and finally tackle the energy crisis and climate change. Herein, the recent progresses of ¹O₂ for energy storage and conversion is summarized, including physical and chemical properties, formation mechanisms, detection technologies, side reactions in rechargeable batteries and corresponding inhibition strategies, and applications in electrocatalysis and photocatalysis. The formation mechanisms and inhibition strategies of ¹O₂ in particular aprotic lithium-oxygen (Li-O₂) batteries are highlighted, and the applications of ¹O₂ in photocatalysis and electrocatalysis is also emphasized. Moreover, the confronting challenges and promising directions of ¹O₂ in energy conversion and storage systems are discussed.