Layered Li(Co0.5Ni0.5)(1-y)FeyO2 (0.0 <= y <= 0.25) oxides were prepared by citric-acid assisted sol-gel method. Elemental and structural properties were investigated by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman scattering (RS) and Mossbauer spectroscopy, and magnetometry. EDX images show a homogeneous distribution of Fe ions. XRD and RS spectroscopy reveal that the materials crystallize as a LiNiO2-LiCoO2-LiFeO2 solid solution with the typical rhombohedral alpha-NaFeO2 structure (R (3) over bar m S.G.) up to y = 0.2 at which composition a secondary phase was observed. For y > 0.2 the XRD results show the appearance of the alpha-LiFeO2 phase with the cubic structure (Fm3m S.G.). The degree of cation mixing investigated by XRD analysis and magnetic measurements is z < 0.04, for y < 0.2. Electrochemical tests of Li(Co0.5Ni0.5)(1-y)FeyO2 (0.0 <= y <= 0.1) oxides in lithium cells show the influence of iron substitution. The best results have been obtained for the composition y(Fe) = 0.05, where the electrical conductivity is maximum. A specific capacity 32 mAh g(-1) is maintained at 8C rate. (C) 2016 Elsevier B.V. All rights reserved.