An innovative soft-chemistry approach to synthesize LiNiVO4

LiNiVO4, a high voltage lithium intercalated cathode-first of its kind with an inverse spinel crystal structure has been synthesized by adopting "soft-chemistry" route, otherwise known as starch-assisted combustion method. Using nitrates as the starting materials, different heat treating conditions were employed with varying amounts of starch, which serves as fuel. Systematic PXRD studies carried out on these heat treated samples indicated monophase formation of LiNiVO4 at a temperature as low as 400 degreesC without any impure phases, especially NiO. From the present investigation, the amount of starch sufficient for accomplishing good crystallinity with electrochemical activity has been optimized as 2 g for 0.01 M of the reactants. Mono-dispersed particles with an average grain size below 1.5 mu are notable from SEM and particle size analysis. The electrochemical activity of thus synthesized LiNiVO4 powders has been examined in terms of charge/discharge cycle performance of Li//LiNiVO4 assembly using 2016 type coin cells. Also, the reversibility of the material with respect to Li+ has been verified through cyclic voltammetric studies. The novelty, flexibility and the significance of the starch-assisted methodology are highlighted. (C) 2002 Elsevier Science B.V. All rights reserved.