In situ Scanning Electron Microscopy (SEM) observation of interfaces within plastic lithium batteries

• Published in: Journal of power sources 1998-11, Vol.76 (1), p.19-29
• Main Authors: Orsini, F, Du Pasquier, A, Beaudoin, B, Tarascon, J.M, Trentin, M, Langenhuizen, N, De Beer, E, Notten, P
• Format: Article
• Language: English
• Subjects: Applied sciences; Dendrite; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Lithium electrode; Morphology; Secondary lithium battery
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/S0378-7753(98)00128-1

Cross-sections of plastic rechargeable Li-cells were observed in a quasi in situ mode by means of a scanning electron microscope. All cells were composed of a composite cathode, containing LiMn 2O 4 as active material, and of a hybrid polymer electrolyte consisting of a polymer matrix embedded with a solution of lithium salt. At the negative side, three kinds of anodes (Li, Cu and graphite) were successively used. The influence of the current density on the morphology of the lithium deposit was studied from these three different configurations. Scanning Electron Microscopy (SEM) evidences for (1) the accumulation of mossy lithium, and (2) the Li-dendrites growth at the interface between Li and electrolyte are given, and correlated to the poor cell cyclability. This deterioration of the interface was confirmed by AC-impedance measurements.