title: Cage-Type Highly Graphitic Porous Carbon-Co3O4 Polyhedron as the Cathode of Lithium-Oxygen Batteries.
abstract: A novel cage-type highly graphitic porous carbon-Co3O4 (GPC-Co3O4) polyhedron was designed and successfully prepared for the first time by executing a two-step annealing of core-shell structured metal-organic frameworks (MOFs). The low graphitic carbon cores were selectively removed during the secondary annealing in air atmospheres, leaving the interior voids due to their lower thermal stability compared with the graphitic carbon shells. Inspired by the unique properties of the cage-type GPC-Co3O4 polyhedron, GPC-Co3O4 was assembled as an oxygen electrode for a rechargeable Li-O2 battery without the additional conductive agent. The efficient generation of Li2O2 during discharging and the reversible decomposition of Li2O2 during charging were clearly observed by XRD patterns and SEM images. The GPC-Co3O4 polyhedron integrates the beneficial properties, including high electronic conductivity, the rigid cage-type structure consisting of the mesoporous walls and interior void space, as well as the uniformly embedded catalytically active Co3O4 nanoparticles. As a result, the GPC-Co3O4 cathode displays a low charge overpotential of 0.58 V, a good rate capability, and a long cycle life in a Li-O2 battery.
authors.affiliation: World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|Faculty of Science and Engineering, Waseda University , 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan.
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.affiliation: Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , 1-1-1, Umezono, Tsukuba 305-8568, Japan.
authors.forename: Shichao
authors.initials: S
authors.lastname: Wu
authors.affiliation: Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics , Nanjing 210016, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics , Nanjing 210016, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Gong
authors.affiliation: World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Huabin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, College of Science, King Saud University , Riyadh 11451, Saudi Arabia.
authors.forename: Saad M
authors.initials: SM
authors.lastname: Alshehri
authors.affiliation: Department of Chemistry, College of Science, King Saud University , Riyadh 11451, Saudi Arabia.
authors.forename: Tansir
authors.initials: T
authors.lastname: Ahamad
authors.affiliation: Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , 1-1-1, Umezono, Tsukuba 305-8568, Japan.
authors.forename: Haoshen
authors.initials: H
authors.lastname: Zhou
authors.affiliation: World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|Faculty of Science and Engineering, Waseda University , 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan.|Department of Chemistry, College of Science, King Saud University , Riyadh 11451, Saudi Arabia.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yamauchi
keywords: cage-type; catalytic graphitization; graphitic carbon−Co3O4; lithium−oxygen battery; metal−organic frameworks; thermal stability