Mesoporous cobalt oxides (Co3O4) with different porosities were employed as the electrochemical catalysts of lithium-oxygen batteries. The mesoporous Co3O4 demonstrated significantly improved round-trip efficiency and specific capacity over the bulk catalyst. Moreover, electrochemical measurement results suggest that the highly open and continuous three-dimensional cubic mesoporous structural features of the catalyst are imperative for its much higher catalytic reactivity than the two-dimensional hexagonal mesoporous Co3O4. A capacity close to 2250 mA h g(-1) (carbon) and a round-trip efficiency of 81.42% were obtained for the mesoporous Co3O4-KIT-6-40 catalyzed air electrode. It is suggested that the mesoporous metal oxide could be a promising catalyst of air electrode for the high performance lithium-oxygen battery. (c) 2012 Elsevier B.V. All rights reserved.