title: A lithium-oxygen battery based on lithium superoxide.
abstract: Batteries based on sodium superoxide and on potassium superoxide have recently been reported. However, there have been no reports of a battery based on lithium superoxide (LiO2), despite much research into the lithium-oxygen (Li-O2) battery because of its potential high energy density. Several studies of Li-O2 batteries have found evidence of LiO2 being formed as one component of the discharge product along with lithium peroxide (Li2O2). In addition, theoretical calculations have indicated that some forms of LiO2 may have a long lifetime. These studies also suggest that it might be possible to form LiO2 alone for use in a battery. However, solid LiO2 has been difficult to synthesize in pure form because it is thermodynamically unstable with respect to disproportionation, giving Li2O2 (refs 19, 20). Here we show that crystalline LiO2 can be stabilized in a Li-O2 battery by using a suitable graphene-based cathode. Various characterization techniques reveal no evidence for the presence of Li2O2. A novel templating growth mechanism involving the use of iridium nanoparticles on the cathode surface may be responsible for the growth of crystalline LiO2. Our results demonstrate that the LiO2 formed in the Li-O2 battery is stable enough for the battery to be repeatedly charged and discharged with a very low charge potential (about 3.2 volts). We anticipate that this discovery will lead to methods of synthesizing and stabilizing LiO2, which could open the way to high-energy-density batteries based on LiO2 as well as to other possible uses of this compound, such as oxygen storage.
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
authors.affiliation: Department of Energy Engineering, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Yun Jung
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.|Department of Metallurgical Engineering, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: Xiangyi
authors.initials: X
authors.lastname: Luo
authors.affiliation: Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Kah Chun
authors.initials: KC
authors.lastname: Lau
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Asadi
authors.affiliation: Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Hsien-Hau
authors.initials: HH
authors.lastname: Wang
authors.affiliation: Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Brombosz
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Wen
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Dengyun
authors.initials: D
authors.lastname: Zhai
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Zonghai
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Miller
authors.affiliation: Department of Energy Engineering, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Yo Sub
authors.initials: YS
authors.lastname: Jeong
authors.affiliation: Department of Energy Engineering, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Jin-Bum
authors.initials: JB
authors.lastname: Park
authors.affiliation: Department of Metallurgical Engineering, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: Zhigang Zak
authors.initials: ZZ
authors.lastname: Fang
authors.affiliation: Conn Center for Renewable Energy Research, University of Louisville, Louisville, Kentucky 40292, USA.
authors.forename: Bijandra
authors.initials: B
authors.lastname: Kumar
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Amin
authors.initials: A
authors.lastname: Salehi-Khojin
authors.affiliation: Department of Energy Engineering, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Yang-Kook
authors.initials: YK
authors.lastname: Sun
authors.affiliation: Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Larry A
authors.initials: LA
authors.lastname: Curtiss
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Khalil
authors.initials: K
authors.lastname: Amine