Layered Li[Li0.15Ni(0.275-x/2)AlxMn(0.575-x/2)]O-2 materials were synthesized via a sol-gel method at 900 degreesC in air. Li[Li0.15Ni(0.275-x/2)AlxMn(0.575-/2)]O-2 and Li2MnO3 phase mixed compounds were obtained. Substitution of Al3+ ions were shown to prevent the structural degradation of the electrode material allowing higher discharge capacities. The 6 mol% aluminum-doped Li[Li0.15Ni0.245Al0.06Mn0.545]O-2 electrode delivered approximately 210 mAh g(-1) discharge capacity in a cut-off range between 2.5 and 4.6 V. It was found that the Al doping on Li[Li0.15Ni(0.275-x/2)AlxMn(0.575-x/2)]O-2 material could decrease the area specific impedance (ASI). (C) 2003 Elsevier Science B.V. All rights reserved.