Synthesis of Li 1−xNi 1+xO 2 using malonic acid as a chelating agent

Abstract

Li 1− x Ni 1+ x O 2 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 °C 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 °C. The FTIR spectra of the precursor without and with 650–800 °C calcination were used to explain the vibrational bonding. At 750 °C and above, only Li 1− x Ni 1+ x O 2 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 Li 1− x Ni 1+ x O 2 powder. In addition, formation mechanism of Li 1− x Ni 1+ x O 2 is proposed. The content of nickel, lithium, Ni 3+/(Ni 3+ + Ni 2+) and mean oxidation state of nickel at 650–800 °C were determined and they show very good agreement. The SEM micrograph is also used to explain the morphology of the powder.