The Structural Stability and Electrochemical Properties of Fe Doped Li(Ni0.575Co0.1Mn0.325)O2

In this study, a positive-electrode material in a lithium secondary battery Li(Ni0.575Co0.1Mn0.325)O2 was synthesized as precursor by co-precipitation. Cathode material was synthesized by adding iron. The synthesized cathode material was analyzed by scanning electron microscope and x-ray diffraction. The analysis of x-ray diffraction showed that the a-axis and c-axis is increased by doping iron. And I(003)/I(104) is increased and I(006)+I(102)/I(101) is decreased. Through this result, it was confirmed that the structural stability is improved. And impedance measurements show that the charge transfer resistance (Rct) is lowered by doping iron. Consequently, electrochemical properties are improved by doping iron. In particular, the cycle characteristics are improved at a high temperature condition (328 K). Structural stabilities are contributing to the cycle properties.