Physical characterization of the charging process of a Li-ion battery and prediction of Li plating by electrochemical modelling
Résumé
This paper deals with occurrence of lithium plating on the negative electrode of lithium-ion batteries, a significant ageing phenomenon known to damage lithium-ion battery performances. Charge transfer process, one of the two different steps of the process of Li insertion in the negative active material being the cause of this ageing, was considered here to be the limiting process. This transfer occurs at short-time scales. The second process, the diffusion of lithium in the solid insertion compound, occurring at relatively long-time scales, has not been fully examined here. The aim of this paper was to develop a new method to evaluate the maximal rate of a charge pulse solicitation to prevent this ageing phenomenon. The approach relies on the use of a fundamental model of lithium ion battery with coupled mass and charge transfer. To validate the method, 2 s microcycles have been performed on a commercial VL41M SAFT cell. Theoretical and experimental works led to the maximum current density to be applied without undesired Li deposition, depending on the state of charge (SOC). The abacus established for the cell of interest can orient further specifications for suitable use of the battery.