A LiNi0.8Co0.15Al0.05O2-graphene composite has been synthesized by a high energy mechanical ball milling (HEMM) process. The structural and morphological features of the synthesized samples are characterized by various techniques. Electrochemical studies on the LiNi0.8Co0.15Al0.05O2-graphene composite are conducted using of the galvanostatic charge-discharge process and electrochemical impedance spectroscopy methods by constructing a lithium-ion cell. The LiNi0.8Co0.15Al0.05O2-graphene composite exhibits a high capacity of >180 mA h/g with good cyclability and high rate capability. The improved electrochemical performance is attributed to increased electrical contact provided by the graphene layer, which reduces the cell polarization. (C) 2012 Elsevier B.V. All rights reserved.