Li intercalation, electronic and thermodynamic properties in H2Ti3O7 bulk: A theoretical study

JUAN, JULIÁN; FERNÁNDEZ-WERNER, LUCIANA; BECHTHOLD, PABLO; JASEN, PAULA V.; FACCIO, RICARDO; GONZÁLEZ, ESTELA A.

COMPUTATIONAL MATERIALS SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2023 vol. 228

0927-0256

We performed Density Functional Theory calculations with Hubbard methodology (DFT + U) in order to study Liintercalation in H2Ti3O7 and the electronic and thermodynamic properties of this doped system. The calculatedvoltages for the three doped systems considered were found to be stable and with promising values. Theirelectronic structure presented a small magnetic moment induced due to the asymmetry present in the spin up andspin down contribution to the densities of states. Also, the systems present a type-n semiconductor behaviour. Acharge transfer of 0.7e- from Li to titanate was observed. Phonon densities of states show the presence of H and Opeaks at high frequencies in these systems. A novel theoretical thermodynamic study on Li intercalation in thistitanate was performed, finding that the doped systems have stable and promising properties. The calculatedbulk’s Gibbs free energy difference was of − 252 kJ⋅mol− 1. The Nudged Elastic Band (NEB) methodology and onthe-fly force field machine learning (MLFF) from ab initio molecular dynamics (AIMD) were applied to determinethe stability sites for Li. From selected diffusion paths for Li, we found that there is one in the structure with anenergy barrier of 0.33 eV. Consequently, this study presents innovative and significant results as a guide forfuture theoretical and experimental works on this potentially Li-ion battery anode material.