A fluoroalkyl iodide additive for Li–O2 battery electrolytes enables stable cycle life and high reversibility

The introduction of CF 3 (CF 2 ) 2 I into the electrolyte leads to the simultaneous formation of LiI as a redox mediator and LiF as a protective layer. This enables long cycle life and high reversibility even at high areal capacity (∼5 mA h cm −2 ).