Solid state mechanical activation method was applied for surface modification of LiMn2O4 by Li-M-O (M = Co, Co+Ni) and for preparation of composite mixed LiMn2O4/LiCoO2 cathode materials. Pristine LiMn2O4 was ground with correspondent precursors (for coating) or with LiCoO2 (for composites) in high-energy planetary mills and then heat treated at different temperatures. As prepared materials were studied by XRD, Li-7 MAS NMR spectroscopy, XPS, SEM and electrochemical cycling. It has been shown that both 'core-shell' and composite materials prepared by mechanochemical process are characterized by superior electrochemical performance due to smaller particles and chemical modification of LiMn2O4. (C) 2010 Elsevier B.V. All rights reserved.