Composite of Li-Rich Mn, Ni and Fe Oxides as Positive Electrode Materials for Li-Ion Battery

A porous layered composite of Li2MnO3 and LiMn1/3Ni1/3Fe1/3O2 (composition: Li1.2Mn0.53Ni0.13Fe0.13O2) is prepared by reverse microemulsion method employing tri-block co-polymer, F068 as a soft-polymer template. The Co-free composite is studied as a cathode material for Li-ion battery. Several samples are prepared by heating the precursor in the temperature range between 500 and 900°C. The N2 adsorption/desorption studies reveal that the product samples possess mesoporosity with broadly distributed pores around 15-50 nm diameter. Pore volume and surface area decrease by increasing the temperature of preparation. Charge-discharge, cycling and rate capability are investigated. The discharge capacity of the sample prepared at 900°C is about 170 mAh g−1 at a specific current of 25 mA g−1 with a good cycling stability. A value of 140 mAh g−1 is obtained at the end of 50 charge-discharge cycles. Discharge capacity of 91 mAh g−1 is obtained at a specific current of 206 mA g−1. A high rate capacity of the composite is attributed to its porous nature.