Improved high-rate cyclability of sol-gel derived Cr-doped spinel LiCr y Mn2-y O4 in an aqueous electrolyte

Spinel-type Cr-doped LiCr (y) Mn2 - y O-4 (y = 0, 0.1, 0.2) electrode materials were prepared via a sol-gel route starting with lithium acetate, manganese acetate and chromium nitrate as raw materials and citric acid as chelating agent. The phase structure and morphology of the materials were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM) techniques. Electrochemical performances of the LiCr (y) Mn2 - y O-4 electrodes in 5 M LiNO3 aqueous electrolyte were investigated using cyclic voltammetry, ac impedance and galvanostatic charge/discharge methods. Electrochemical results showed that Cr-doping could markedly improve the high-rate charge/discharge cyclability of the LiMn2O4 electrode in 5 M LiNO3 aqueous solution.