Effect of Cr-sources on performance of Li 1.05Cr 0.04Mn 1.96O 4 cathode materials prepared by slurry spray drying method

Abstract

The effect of Cr-sources on the performance of Li 1.05Cr 0.04Mn 1.96O 4 prepared by slurry spray drying method was studied by adopting three different chromic compounds, Cr 2O 3, Cr 2(SO 4) 3 and Cr(CH 3COO) 3, respectively. The prepared powder materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), laser particle size analyzer and Brunauer–Emmett–Teller (BET) specific surface area test. Electrochemical performances of these cathode materials were investigated by electrochemical impedance spectroscopy (EIS) and charge–discharge tests with Li/LiCr x Mn 2− x O 4 coin-type batteries. The results indicate that porous spherical particles with average particle size of about 24 μm can be obtained by slurry spray drying process. Using Cr(CH 3COO) 3 as Cr-source resulted in the better mixing properties, which can make the as-prepared CA-Li 1.05Cr 0.04Mn 1.96O 4 having smaller lattice parameter, smaller grain size and better structure stability, and consequently the obtained sample showed low charge transfer impedance and electrochemical polarization, and exhibited good electrochemical performance at elevated temperature.