In situ SEM study of the interfaces in plastic lithium cells

The interfaces of lithium cells were studied upon cycling within a scanning electron microscope (SEM). The LiMn₂O₄-cathode and the electrolyte consisted of a polymer matrix embedding a solution of LiPF₆, while three types of anodes, Li, Cu and graphite, were tested and compared. For each configuration the morphology of the lithium deposit was correlated to the current density. Mossy lithium, at low current, and Li-dendrites, at high current, were observed at the Cu/electrolyte and Li/electrolyte interfaces, while no special morphology was noted at the graphite/electrolyte interface.