Cell capacity fade curves have often have a recognisable knee:
Anseán et al. found that the Li deposition starts to get irreversible at the turning point of sudden capacity drop. 
Lithium dendrite growth has a positive feedback loop.
While Lithium plating is reversible, cell capacity can recover during rest.
Part of Cell capacity fade, Lithium plating, Cell degradation, Lithium plating as unwanted side reaction in commercial Li-ion cells – A review.
 Operando lithium plating quantification and early detection of a commercial LiFePO 4 cell cycled under dynamic driving schedule (2017)
 Lithium plating in a commercial lithium-ion battery – a low-temperature aging study (2015)