Nominal LiAlxCo1-xO2 with x ranging from 0.1 to 0.3 was prepared by heating mixture of Al(OH)(3), Co3O4 and LiOH at 750 degrees C in air. The effect of substitution of non-transition metal, Al, in LiCoO2 is investigated as a 4 V cathode for Lithium ion. X-ray diffraction (XRD) indicates formation of a single phase (R (3) over bar m) within this range of substitution. When cycled between 4.5 and 2.5 V vs. Li/Li+ ta current density of 1 mA cm(-2), the LiAl0.15Co0.85O2 cathode exhibits reversible capacity of 160 mA h g(-1) initially. XRD of the cathode made at the end of 10 cycles reveals no significant change on host structure.