Resumo

MENDIZABAL, Fernando; SANTA ANA, María Angélica; BENAVENTE, Eglantina  e  GONZALEZ, Guillermo. QUANTUM CHEMICAL MODEL FOR LITHIUM ELECTROCHEMICAL INTERCALATION INTO MOLYBDENUM DISULFIDE. J. Chil. Chem. Soc. [online]. 2003, vol.48, n.4, pp.69-75. ISSN 0717-9707.  http://dx.doi.org/10.4067/S0717-97072003000400011.

Voltage- and incremental charge capacity-composition curves for the electrochemical formation of intercalates Li_xMoS₂ were analyzed at the molecular level by developing a quantum chemical model focused on the variation of the electron chemical potential. Experimentally observed trends of the charge capacity in the range 0<x<0.6 are successfully described by the global hardness index as defined within the density functional theory. Contrasting with classical descriptions like the gas lattice model assuming complete lithium-MoS₂ one electron transfer, proposed model leads, agreeing with previous experimental evidence, to a system in which electron density is partially retained in the lithium atom. The model permits moreover to identify a sequence of octahedral and tetrahedral sites as the more favorable migration pathway for the diffusion of lithium through the interlaminar space

Palavras-chave : Electron chemical potential; quantum chemical model; molydenum disulfide; electrochemical charge capacity; lithium intercalation.