Effect of Fluorine on the Electrochemical Properties of Layered Li(Ni0.5Mn0.5)O2 Cathode Materials

Abstract

Due to its advantage in cost and thermal safety, more and more attention has recently been paid to layered Li(Ni0.5Mn0.5)O2 as an alternative to LiCoO2- and LiNiO2- based cathode materials for Li-ion secondary batteries. For practical adoption of the material in commercial Li-ion cells for high energy/power napplications, however, more works need to be done to increase its specific capacity and power capability. Recently, we showed that replacement of Ni/Mn with small amount of Co increased discharge capacity, improved cycling stability, and lowered impedance of Li(Ni0.5Mn0.5)O2. In this work, the effect of oxygen subsitution with fluorine on the electrochemical properties of Li(Ni0.5Mn0.5)O2 has been investigated.