Synthesis and Storage Performance of the Doped LiMn2O4 Spinel

Abstract

A series of spinel-doped lithium manganese oxides, (, , ), (, , , ), (, , , ), have been prepared using the solid-state reaction of a titanium-doped electrolytic manganese dioxide, lithium hydroxide, and doping agents. The oxides have been characterized using several advanced techniques, such as X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared analysis, Raman spectroscopy, thermogravimetric analysis, differential scanning calorimetry, cyclic voltammograms and charge/discharge cycles. The experimental results show that the sample, prepared at 600°C, showed the best electrochemical performance during the charge/discharge tests and storage process in all samples. In the voltage region of 4.6–, the initial capacities of the fresh, discharge-storage, and charge-storage cell for the sample are 206, 144, and , respectively. In the voltage region of 4.3–, the capacity fade of the sample was 5.3% in 150 cycles. After being doped by titanium ions, the spinel exhibits a lower lattice constant and stronger bond than a pure spinel does.