From ‘core–shell’ to composite mixed cathode materials for rechargeable lithium batteries by mechanochemical process

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, 7Li 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.