Understanding oxygen reactions in aprotic Li-O2batteries
Ma Shunchao1, 2, †, 
, Zhang Yelong1, 2, †, , Cui Qinghua1, 2, Zhao Jing1, 2, Peng Zhangquan1, ‡,
, Zhang Yelong1, 2, †, , Cui Qinghua1, 2, Zhao Jing1, 2, Peng Zhangquan1, ‡, Proposed reaction mechanism of Li-O2recharge. The OER process associated with stage I (sloping and catalyst-insensitive) is attributed to a de-intercalation process via a solid-solution route from the outer part of Li2O2to form LiO2-like species on the surface (Li2O2→ LiO2+ Li++ e–), where LiO2-like species disproportionate to evolve O2(LiO2+ LiO2→ Li2O2+ O2), yielding an overall 2e–/O2OER process (Li2O2→ 2Li++ O2+ 2e–). The OER process at the flat potential plateau (stage II) is attributed to the oxidation of bulk Li2O2particles to form Li+ions and O2(Li2O2→ 2Li++ 2e–+ O2) via a two-phase transition. Lastly, a rising charge plateau after stage II has been assigned to the decomposition of carbonate-type byproducts and electrolyte.[
