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Characterization of Layered LiMO 2 Oxides for the Oxygen Evolution Reaction of Metal–Air Batteries (M=Mn, Co, Ni)

2014; Wiley; Volume: 80; Issue: 2 Linguagem: Inglês

10.1002/cplu.201402107

2192-6506

Veronica Augustyn, Arumugam Manthiram,

Advanced battery technologies research

Abstract The behavior of layered LiMO 2 (M=transition metal) oxides has been investigated systematically as a function of composition for the oxygen evolution reaction (OER) in alkaline electrolytes. The rich variety of LiMO 2 compositions with the O3‐type layered structure makes this class of materials an excellent testbed for understanding the effects of the nature and oxidation states of the transition‐metal ions on the OER. Accordingly, the OER behaviors of a range of LiMO 2 oxide solid solutions are presented here: LiCo 1− x Mn x O 2 , LiNi 1− x Mn x O 2 , and LiCo 1− x Ni x O 2 with 0.25≤ x ≤ 0.7. It is found that the OER activity increases with decreasing Mn content, and the Ni‐rich compositions exhibit high OER activities. Furthermore, the pre‐OER potential region displays contributions from surface faradaic reactions that involve Ni and Co. The overall higher activity of the Ni‐ and Co‐rich compositions might be due to the in situ transformation of the LiMO 2 surface into a highly active electrocatalyst.