Lithium-based transition-metal oxides for battery electrodes analyzed by x-ray photoelectron spectroscopy. I. LiNi0.8Co0.15Al0.05O2

X-ray photoelectron spectroscopy (XPS) and x-ray-induced Auger electron spectroscopy were used to analyze untreated LiNi0.8Co0.15Al0.05O2 powder obtained from TODA America. X-ray photoelectron and x-ray-induced Auger electron spectra were obtained using incident monochromatic Al Kα radiation at 0.83401 nm. A survey spectrum together with Ni 2p, Co 2p, Ni LMM, O 1s, C 1s, Al 2s, Ni 3s, Co 3s, Al 2p, Ni 3p, Co 3p, and Li 1s are presented. The spectra indicate the principal core level photoelectron and Auger electron signals and show carbon with only minor sulfur contamination. Making use of the O 1s, Al 2s, Ni 3p, Co 3p, and Li 1s lines and neglecting the components related to surface contaminants, XPS quantitative analysis reveals an altered stoichiometry of the air-exposed powder surface of LiNi0.2Co0.03Al0.1O0.7.