In this work, LiCoPO4 nanoparticles were synthesized by supercritical fluid method using cobalt nitrate hexahydrate (Co(NO3)2 6H2O) and cobalt acetate tetrahydrate (C4H6CoO4 4H2O) as starting materials. The effect of starting materials on particle morphology, size, and the crystalline phase were investigated. The as-synthesized samples were systematically characterized by XRD, TEM, STEM, EDS, BET, and TG and charge-discharge measurements. In addition, Rietveld refinement analysis was performed. The electrochemical measurements of LiCoPO4 nanoparticles have shown differences in capacities depending on the starting materials used in the synthesis and the results have been discussed in this paper.