Intercalation geometry of AlF 3 in HOPG for the design of novel rechargeable cell electrodes

RODRÍGUEZ, S.J.; CANDIA, A.E.; ALBANESI, E.A.; PASSEGGI, M.C.G.; RUANO, G.

Virtual

Encuentro; ENCONTRO DE OUTONO 2021; 2021

Sociedade brasileira de fisica

Rechargeable ion batteries have attracted more attention than other battery energy sourcesdue to their advantages as recycling charging devices with high energy capacity, highperformance and easy adaptation to the industry. Rechargeable batteries are based on theintercalation (or de-intercalation) of ions/molecules in the anodes/cathodes of batteries whenthey are charged/discharged. Graphite is one of the most used materials to buildcathodes/anodes in batteries since its layered structure is highly configurable, being able toaccommodate a variety of ions/molecules to form intercalation compounds. Studies of thelast decades have provided important information on different ions/molecules that can beintercalated in graphite like Li - [1], Mg - [2], Na - [3], AlCl - 4 [4,5], among others. However,identifying a suitable electrode ion/molecule combination with desirable electrochemicalproperties remains a major challenge for ion rechargeable batteries. The capacity andcharge (discharge) rate of batteries is related to the processes of intercalation, diffusion andadsorption of atoms/molecules in graphite [6]. In this work, using first-principle calculationsbased on density functional theory (DFT), we studied the aluminum fluoride (AlF 3 )intercalation in highly oriented pyrolytic graphite (HOPG) by two stages of intercalation. Wediscuss the most stable configuration, the charge transfer and the diffusion of the AlF 3molecule —the migration pathways and energy barriers—. Furthermore, we compare ourresults with chemically similar molecules. This study of the AlF 3 intercalation in graphitecould be very helpful for designing new batteries based on AlF 3 .