Capacity plunge of lithium-ion batteries induced by electrolyte drying-out: Experimental and Modeling Study

After a long-term linear fading, the capacity of some Li-ion batteries could plunge, transiting to a nonlinear fading stage. To distinguish the batteries inclined to nonlinear aging in near future is paramount for the reuse of the retired batteries from electric vehicles. However, the mechanism of capacity plunge remains controversial and at least lithium plating, rollover mechanism, electrolyte depletion and their combinations have been proposed as possible triggers. Here in this paper, we propose that capacity plunge could be induced solely by the electrolyte depletion while the presence of Li plating or rollover is not required. A series of in-situ and ex-situ experiments are performed to identify the change of battery before and after the inflexion of capacity fading. An electrode model which introduces a coefficient to reflect the influence of electrolyte drying-out has been proposed.