Li1±xNi0.5Mn1.5O4(x=0.05,0) spinel powders were synthesized using a solid-state reaction.Their structures were characterized by X-ray diffraction,scanning electron microscopy and Raman spectroscopy.Their electrochemical properties for use as active cathode materials in lithium-ion batteries were measured.The LiNi0.5Mn1.5O4,Li1.05Ni0.5Mn1.5O4 and Li0.95Ni0.5Mn1.5O4 samples crystallized in Fd 3m,Fd 3m and P4332,respectively.The LiNi0.5Mn1.5O4 and Li0.95Ni0.5Mn1.5O4 samples exhibited better cycle performance than the Li1.05Ni0.5Mn1.5O4 sample,while Li0.95Ni0.5Mn1.5O4 had the worst rate performance.Thus,it appears unnecessary to introduce nominal lithium nonstoichiometry in LiNi0.5Mn1.5O4 electrode materials.
