Kinetic Monte Carlo applied to the electrochemical study of the Li-ion graphite system

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

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2020

0013-4686

To delve deeper into the kinetics involved in the staging phenomena of lithium insertioninto graphite, it is necessary to develop theoretical models that emulate the physical phenomenon involved. In the present work kinetic Monte Carlo simulations are used tocarry out a thorough analysis of the Li-ion graphite system, with the twofold aim ofproviding atomistic support for interpretations based on several experimentalelectrochemical techniques commonly used in the laboratory and of making theoreticalpredictions for future experimental work. Cyclic voltammograms andchronoamperometric transients are obtained, and diffusion coefficients and exchangecurrent densities are calculated at different Li loadings of graphite. These results arecompared with selected experimental data from the literature. In this way, there emergedetails that cannot be observed in ordinary experiments due tomethodological/instrumental limitations. For example, it is found thatchronoamperometric responses are different for intercalation and deintercalation, thelatter being a faster process. The reason why these phenomena are different is revealed,supporting and widening experimental assumptions. The present results also suggest that the intrinsic hysteresis observed in experimental work (and in simulations) is due tokinetic factors.