Preparation and electrochemical behavior of sol–gel LiNi0.3Co0.70−xMxO2 (M = Mn, Al)

LiNi0.3Co0.70−xMxO2 (M = Mn, Al) powders were synthesized using as a precursor, an aqueous or alcoholic mixture of metal organic salts with citric acid as chelating agent. Resulting powders were characterized by thermal analysis (TGA–DTA), X-ray diffraction (XRD), infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Desired crystalline structure was developed at 700 °C. LiNi0.3Co0.7O2 powders exhibit a layered α-NaFeO2 structure (space group: R3¯m). Electrochemical characteristics of the synthesized materials were evaluated on Swagelock™ cells on a Li/LiNi0.3Co0.70−xMxO2 configuration. For LiNi0.3Co0.7O2 the initial capacity was 142 ± 5 mAh/g and for LiNi0.3Co0.6Mn0.1O2 similar capacity was exhibited. On the other hand, a decrease on cell capacity was observed when Co substitution was done with aluminum.