EXPERIMENTAL STUDY OF AlF3 IN GRAPHITE FOR APPLICATIONS IN ALUMINIUM-BASED INTERCALATION BATTERIES.

ADRIANA CANDIA; SINDY JULIETH RODRÍGUEZ SOTELO; ALBANESI, EDUARDO ALDO; MARIO PASSEGUI; GUSTAVO RUANO

Sao Pablo

Encuentro; Encontro de Outono 2021 - Sociedade Brasileira de Física; 2021

The study and development of rechargeable energy storage systems such as batteries [1], fuel cell [2], electrochemical capacitors and solar cells, among others [3,4], has attracted considerable attention in recent years. In particular, the rechargeable graphite-based ion batteries are considered a promising alternative for energy storage applications easily adapted to industry, and nowadays are one of the most studied and widely known technologies. Basically, the battery charge/discharge mechanism results from the intercalation/de-intercalation of atoms, ions or molecules in a cathode material and it is of utmost importance to investigate the materials that are used as electrodes as well as the atoms/molecules that are intercalated. One of the most used materials to build cathodes/anodes in batteries is graphite since its layered structure is highly configurable, being able to accommodate a variety of ions/ molecules to form intercalation compounds. In this work, we present an experimental study of the intercalation process of aluminium fluoride (AlF3) in highly oriented pyrolytic graphite (HOPG) by direct evaporation at room temperature and under ultra-high vacuum conditions, taking advantage of a variety of surface analysis techniques. We characterize the system in different instances of AlF3 dosing by X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), Auger Electron Spectroscopy (AES) and Rutherford backscattered ion spectroscopy (RBS). The interpretation of our results was assisted by ab-initio calculations in the density functional formalism (DFT). We determined that the interlayer diffusion process in graphite dominates over adsorption and the penetration thickness in the substrate is controlled by the amount of surface defects.