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.