Synthesis, characterization, and cell performance of LiNiVO4 cathode materials prepared by a new solution precipitation method

Abstract

LiNiVO 4 was prepared by a new solution precipitation process using acetylacetonate as a reagent. The effects of pH value on the purity, grain size, lithium stoichiometry, and cycling behavior of LiNiVO 4 were studied. Solution precipitation performed in an acidic medium of pH=3 with heat-treatment at 450°C for 12 h yielded pure and fine LiNiVO 4 powders which showed lithium stoichiometry of 0.971 and narrow grain-size of 0.34 μm. Under neutral and basic conditions, the LiNiVO 4 particles were contaminated with NiO and formed aggregates with a larger grain size in the 0.36–0.54 μm range. The resulting LiNiVO 4 powders were characterized by TGA, XRD, ICP-AES, SEM, and AFM techniques. Moreover, the cycle behavior of LiNiVO 4 products synthesized by a high temperature solid state method and this new solution precipitation method was compared and discussed.