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

Singlet oxygen (term symbol 1 Δ g , hereafter 1 O 2 ), 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 1 O 2 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 1 O 2 in particular aprotic lithium-oxygen (Li-O 2 ) batteries are highlighted, and the applications of 1 O 2 in photocatalysis and electrocatalysis is also emphasized. Moreover, the confronting challenges and promising directions of 1 O 2 in energy conversion and storage systems are discussed.