Crystallization mechanism of LiNiO2 synthesized by Pechini method

Submicron and stoichiometric LiNiO2 was successfully crystallized at low te mperatures using Pechini method, which was developed to crystallize mixed c ation oxide from organic precursors. The crystal structure and the effect o f oxygen were investigated in this study. The synthesis of LiNiO2 was descr ibed as the decomposition of citrate into Li2CO3 and NiO, which subsequentl y formed LixNi2 . xO2 at temperatures higher than 500 degreesC in air. When the precursor was calcined at 300 degreesC in O-2 atmosphere, Ni2O3, NiO, Li2CO3 and LixNi2-xO2 were found. Structural analysis showed that the cryst allization of LixNi2-xO2 was significantly enhanced by the presence of oxyg en at lower temperatures. Li0.98Ni1.02O2 and Li0.85Ni1.15O2 were obtained i n O-2 and air atmosphere, respectively. The I(003)/I(104) ratio of LixNi2-x O2 formed is higher in pure oxygen (1.43) than that in air (1.2). Thus, it is expected that LixNi2-xO2 synthesized in Oz atmosphere exhibits better el ectrochemical properties than that synthesized in air. (C) 2001 Elsevier Sc ience B.V. All rights reserved.