title: New Insights into the Instability of Discharge Products in Na-O2 Batteries.
abstract: Sodium-oxygen batteries currently stimulate extensive research due to their high theoretical energy density and improved operational stability when compared to lithium-oxygen batteries. Cell stability, however, needs to be demonstrated also under resting conditions before future implementation of these batteries. In this work we analyze the effect of resting periods on the stability of the sodium superoxide (NaO2) discharge product. The instability of NaO2 in the cell environment is demonstrated leading to the evolution of oxygen during the resting period and the decrease of the cell efficiency. In addition, migration of the superoxide anion (O2(-)) in the electrolyte is observed and demonstrated to be an important factor affecting Coulombic efficiency.
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU , 48080 Bilbao, Spain.
authors.forename: Imanol
authors.initials: I
authors.lastname: Landa-Medrano
authors.affiliation: Institute of Physical Chemistry, Justus-Liebig-University Giessen Heinrich-Buff-Ring 17, 35392 Gießen, Germany.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pinedo
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.|Department of Chemistry and Biochemistry, Ohio State University , 100 West 18th Avenue, Columbus, Ohio 43210, United States.
authors.forename: Xuanxuan
authors.initials: X
authors.lastname: Bi
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU , 48080 Bilbao, Spain.
authors.forename: Idoia
authors.initials: I
authors.lastname: Ruiz de Larramendi
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU , 48080 Bilbao, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Lezama
authors.affiliation: Institute of Physical Chemistry, Justus-Liebig-University Giessen Heinrich-Buff-Ring 17, 35392 Gießen, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Janek
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Khalil
authors.initials: K
authors.lastname: Amine
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU , 48080 Bilbao, Spain.|CIC Energigune , Albert Einstein 48, 01510 Miñano, Álava Spain.
authors.forename: Teófilo
authors.initials: T
authors.lastname: Rojo
keywords: Na−O2 batteries; discharge stability