Multiple-ion-doped lithium nickel oxides as cathode materials for lithium-ion batteries

Several multiple-ion-doped lithium nickel oxides with formula of LiMnxCoyNi1-x-yO2 were synthesized via solid-state reactions at high temperature. These phase-pure LiMnxCoyNi1-x-yO2 compounds have a layered hexagonal structure, and their electrochemical properties were systematically investigated. Typical cathodes can deliver a capacity in the range of 140-180 mAh/g with fairly stable cyclability. The kinetics of lithium insertion in these cathodes were characterized via ac impedance measurements. These newly developed compounds show great promises as cathode materials for future lithium-ion batteries with low cost and less toxicity. (C) 2003 Elsevier Science B.V. All rights reserved.