In situ Raman spectroscopy of layered solid solution Li2MnO3-LiMO2 (MÂ =Â Ni, Mn, Co)

► In situ Raman spectroscopy of layered solid solution of Li2MnO3-LiMO2 (M = Ni, Mn, and Co). ► Impedance decrease steadily and reaches minimum at 4.47 V ► Less steep increase in impedance as cell voltage traversed the first charge 4.5 V plateau. ► Lithium extraction occur from transition metals as well as lithium layers in 4.1-4.4 V voltage range. ► Extraction of oxygen along with lithium ions from the transition metal layers takes place after 4.5 V.