Synthesis of Li1-xNi1+xO2 using malonic acid as a chelating agent

Li1-xNi1+xO2 powder was synthesized by polymerised complex method using malonic acid as a chelating agent. The carboxylate precursor was calcined in the temperature range 650-800 degreesC for 14-48 h. The TG curves of malonic acid, lithium acetate dihydrate, nickel acetate tetrahydrate and the precursor were studied at 29.52-600 degreesC. The FTIR spectra of the precursor without and with 650-800 degreesC calcination were used to explain the vibrational bonding. At 750 degreesC and above, only Li1-xNi1+xO2 phase was detected. The maximum [I-(003)/I((104))] and minimum [I(006+102)/I-(101)] intensity ratios of the XRD spectra were used to determine the optimum temperature and time of calcination for preparation of Li1-xNi1+xO2 powder. In addition, formation mechanism of Li1-xNi1+xO2 is proposed. The content of nickel, lithium, Ni3+/ (Ni3+ + Ni2+) and mean oxidation state of nickel at 650-800 degreesC were determined and they show very good agreement. The SEM micrograph is also used to explain the morphology of the powder. (C) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved.