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Oxide Catalysts for Rechargeable High‐Capacity Li–O 2 Batteries
Author(s) -
Oh Si Hyoung,
Nazar Linda F.
Publication year - 2012
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201200018
Subject(s) - pyrochlore , materials science , catalysis , oxide , crystallite , chemical engineering , inorganic chemistry , oxygen , carbon fibers , anode , metal , precipitation , electrode , metallurgy , chemistry , composite material , phase (matter) , biochemistry , physics , organic chemistry , composite number , meteorology , engineering
Nano‐crystalline mixed metal oxides with an expanded pyrochlore structure are synthesized by a chemical precipitation route in alkaline media. The high concentration of surface active sites afforded by their high surface area, intrinsically variable oxidation state and good electron transport lead to promising electrocatalytic properties for oxygen evolution in Li‐O 2 cells, yielding rechargeable discharge capacities over 10 000 mAh g −1 and lowering anodic overpotentials significantly. The discharge capacity of the Li‐O 2 cell is increased further when a small amount of gold is deposited on the pyrochlore oxide, which serves as a more efficient oxygen reduction catalyst. The amount of catalyst necessary for oxygen evolution performance is reduced to as little as 5 wt% by supporting the highly‐divided pyrochlore oxide crystallites on carbon using in‐situ deposition methods.