Synthesis and Characterization of Novel, High-Capacity, Layered $LiMn_{0.9}Ni_{0.05}Fe_{0.05}O_2$ as a Cathode Material for Li-Ion Cells

A novel layered-material, $LiMn_{0.9}Ni_{0.05}Fe_{0.05}O_2$ with $O3-LiCoO_2$ structure and high electrochemical stability, has been synthesized by an ion exchange method. Specific capacity values of 250 mAh $g^-1$ at C/10 rate and 210 mAh $g^-1$ at C/2 rate have been obtained with little loss in capacity during 30 charge-discharge cycles conducted in the study. The X-ray diffraction and infrared spectroscopy data on the cycled samples suggest that the layered structure in $LiMn_{0.9}Ni_{0.05}Fe_{0.05}O_2$ is preserved after repeated charge-discharge cycles supporting stable specific capacity values. Owing to the high capacity and good stability, $LiMn_{0.9}Ni_{0.05}Fe_{0.05}O_2$ is attractive as a cathode material in Li-ion cells