Affiliation:
1. College of Physics and Electronic Information Inner Mongolia Normal University Hohhot Inner Mongolia China
2. Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials Hohhot Inner Mongolia China
3. Inner Mongolia Engineering Research Center for Rare Earth Functional and New Energy Storage Materials Hohhot Inner Mongolia China
Abstract
AbstractThe effect of niobium ions with high‐valence doping on high‐voltage LiNi0.5Mn1.5O4 (LNMO) materials was investigated. LiNi0.5Mn1.5−xNbxO4 was prepared by doping high‐valent niobium ions into LiNi0.5Mn1.5O4 material using the organic assisted combustion method. The experimental samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), electrochemical impedance (EI), and cyclic voltammetry (CV) analysis. The experimental results show that ‐doping with high‐valence niobium ions changes the orientation of the crystal plane growth of spinel particles, and the morphology of these particles changes from the octahedral shape before doping to the spherical shape after doping. With the increase in doping amount, the crystal structure changes gradually, resulting in the Li0.96Nb1.01O3 impurity phase. The doping of high valence‐niobium ions increases the content of Mn3+ in the material, resulting in the appearance of a 4 V discharge platform and the formation of a 4.7 and 4 V discharge platforms. The doping of Nb can improve the cycling stability of LiNi0.5Mn1.5O4 material, but the specific capacity of the material is reduced.
Publisher
Institution of Engineering and Technology (IET)