With the aim of achieving a high-performance 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2 material, a series of 0.5Li2MnO3·0.5LiMnxNiyFe(1−x−y)O2 (0.3 ≤ x ≤ 0.5, 0.4 ≤ y ≤ 0.5) samples with low Fe content was synthesized via coprecipitation of carbonates. Its crystal structure and electrochemical performance were characterized by means of powder X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, galvanostatic charge/discharge testing, cyclic voltammetry, and electrochemical impedance spectra. Rietveld refinements with a model integrating R