Deactivation of redox mediators in lithium-oxygen batteries by singlet oxygen oleh Won-Jin Kwak, Hun Kim, Yann K. Petit, Christian Leypold, Trung Thien Nguyen, Nika Mahne, Paul Redfern, Larry A. Curtiss, Hun-Gi Jung, Sergey M. Borisov, Stefan A. Freunberger, Yang-Kook Sun