title: Surface Reactivity of a Carbonaceous Cathode in a Lithium Triflate/Ether Electrolyte-Based Li-O2 Cell.
abstract: Li-O2 batteries are currently one of the most advanced and challenging electrochemical systems with the potential to largely overcome the performances of any existing technology for energy storage and conversion. However, these optimistic expectations are frustrated by the still inadequate understanding of the fundamentals of the electrochemical/chemical reactions occurring at the cathode side, as well as within the electrolyte and at the three-phase interface. In this work, we illustrate the evolution of the morphology and composition of a carbonaceous cathode in the first discharge/charge in a Li-O2 cell with an ether-based electrolyte by X-ray photoemission spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. Experiments have been carried out ex situ on electrodes recuperated from electrochemical cells stopped at various stages of galvanostatic discharge and charge. Apparently, a reversible accumulation and decomposition of organic and inorganic precipitates occurs upon discharge and charge, respectively. These precipitations and decompositions are likely driven by electrochemical and chemical parasitic processes due to the reactivity of the cathode carbonaceous matrix.
authors.affiliation: Department of Chemistry, Sapienza University of Rome , P.le Aldo Moro 5, Rome 00185, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Carboni
authors.affiliation: Department of Science, University of Basilicata , V.le Ateneo Lucano 10, Potenza 85100, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Brutti
authors.affiliation: Department of Chemistry, Sapienza University of Rome , P.le Aldo Moro 5, Rome 00185, Italy.
authors.forename: Andrea G
authors.initials: AG
authors.lastname: Marrani
keywords: Fourier transform infrared spectroscopy; Li−O2 battery; X-ray photoelectron spectroscopy; cathode surface reactivity; transmission electron microscopy