Characterization of the carbon-coated LiNi1−yCoyPO4 solid solution synthesized by a non-aqueous sol-gel route

摘要: Nanosize carbon-coated samples of the solid solution LiNi1−y Co y PO4 were prepared and investigated with respect to high-voltage cathode materials (4–5 V) for Li-ion batteries. For syntheses, a modified non-aqueous sol-gel approach under argon atmosphere was applied. Crystal structure morphology products analyzed by X-ray powder diffraction, scanning electron microscopy, Raman spectroscopy. Phase pure crystallize in olivine-type linear relation between lattice parameters chemical composition. The mean crystal size particles is smaller than 300 nm increasing agglomeration towards higher nickel content. Effects Ni/Co ratio on P-O M-O bonds explored FTIR UV/VIS measurements, too. Substitution Ni Co causes larger cell volumes, longer atomic distances, weaker bonds. Additional studies focus mechanism formation LiNiPO4 conditions phosphide by-products Ni3P Ni12P5 carbothermal reduction. electrochemical properties all compounds galvanostatic charge/discharge measurements differential capacity analysis. small process lead superior comparison common solid-state synthesis. Cyclability whole solid-solution evaluated first time. content 33 %, voltage shifted level positive effect retention observed.