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

Año: 2020 vol. 331

0013-4686

To delve deeper into the kinetics involved in the staging phenomena of lithium insertion into graphite, itis necessary to develop theoretical models that emulate the physical phenomenon involved. In thepresent work kinetic Monte Carlo simulations are used to carry out a thorough analysis of the Li-iongraphite system, with the twofold aim of providing atomistic support for interpretations based onseveral experimental electrochemical techniques commonly used in the laboratory and of makingtheoretical predictions for future experimental work. Cyclic voltammograms and chronoamperometrictransients are obtained, and diffusion coefficients and exchange current densities are calculated atdifferent Li loadings of graphite. These results are compared with selected experimental data from theliterature. In this way, there emerge details that cannot be observed in ordinary experiments due tomethodological/instrumental limitations. For example, it is found that chronoamperometric responsesare different for intercalation and deintercalation, the latter being a faster process. The reason why thesephenomena are different is revealed, supporting and widening experimental assumptions. The presentresults also suggest that the intrinsic hysteresis observed in experimental work (and in simulations) isdue to kinetic factors