Synthesis and Electrochemical Performance of High Voltage Cycling LiM[sub 0.05]Co[sub 0.95]O[sub 2] as Cathode Material for Lithium Rechargeable Cells

Substituted cobalt oxides, and , have been synthesized using solid-state technique and their performance in a 2032-type lithium rechargeable coin cell is reported. The synthesized powders were structurally analyzed using X-ray diffraction (XRD) and the surface morphology evaluated with scanning electron microscopy. XRD patterns indicate that single-phase materials were formed involving Al-doped Electrochemical studies were carried out in the voltage range 3.5-4.5 V ( vs. Li metal) using 1 M in ethylene carbonate/dimethyl carbonate as electrolyte. The doping involving 5% Mg resulted in a charge/discharge capacity of ∼160 mAh/g at C/5 rate and remained stable even after 50 cycles. To the best of our knowledge, this is the first time that such high stable capacities have been obtained involving doped when cycled up to 4.5 V.