Mg(OH)(2) is coated on the surface of semi-crystalline LixNi1-yCoyO2. By further heating the coated sample, the surface is modified. This lowers the initial discharge capacity and improves the cycle-reversibility of a test lithium-ion cell, which was made with surface-modified LixNi1-yCoyO2 as the cathode material. (C) 2000 Elsevier Science S.A. All rights reserved.