Electronic, Structural, and Electrochemical Properties of LiNixCuyMn2–x–yO4 (0 < x < 0.5, 0 < y < 0.5) High-Voltage Spinel Materials

First principles computation is carried out for investigating the electronic, structural, and electrochemical properties of LiM1/2Mn3/2O4 (M = Ti, V, Cr, Fe, Co, Ni, and Cu). The computation results suggest that doping with Co or Cu can potentially lower Li diffusion barrier as compared to Ni doping. Our experimental research has focused on LiNixCuyMn2–x–yO4 (0 < x < 0.5, 0 < y < 0.5), and we found that the amount of Cu will affect the lattice parameters, the cation disorder in the spinel lattice, the particle morphology, as well as the electrochemical properties. Crystal structures, electronic structures, and electrochemical properties of LiNixCuyMn2–x–yO4 (0 < x < 0.5, 0 < y < 0.5) are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray absorption spectroscopy (XAS), and electrochemical measurements including potentiostatic intermittent titration technique (PITT). With detailed electrochemical measurements and in situ XAS experiments of LiNi0.25Cu0.25Mn1.50O4, the proposed expl...