Fractional and integer stages of lithium ion-graphite systems. The role of electrostatic and elastic contributions

GAVILÁN-ARRIAZU, E. M.; J. M. HÜMÖLLER; O. A. PINTO; B. A. LÓPEZ DE MISHIMA; E. P. M. LEIVA; O.A. OVIEDO

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2020

1463-9076

n the present work we analyze the hot topic of integer and fractional stages lithium-ion batteries by Monte Carlo simulations. While fractional stages have been proposed through several experimental, simulations and theoretical measurements, in other experimental techniques, such as electrochemical ones, there is no evidence for them. In previous work, we have analyzed the thermodynamics and kinetics of lithium-on intercalation using a potential based on empirical parameterization, where multiple stages (integer and fractional) were found and analyzed. The present simulations suggest that, if we consider repulsive elastic interactions in addition to electrostatic ones, the Hamiltonian symmetry is broken and there is no evidence for fractional stages. The physical origin of these repulsive interaction is assigned to the increasing graphite layer separation during lithium-ion intercalation. In the light of these simulations, selected experimental data are revisited, validating the novel