Nb-doped and Al2O3 + B2O3-coated granular secondary LiMn2O4 particles as cathode materials for lithium-ion batteries

摘要

In this work, to improve the cyclability and high-temperature performance of cubic spinel LiMn _(2) O _(4) (LMO) as cathode materials, Nb ~(5+) -doped LiMn _(2) O _(4) powders coated and uncoated with Al _(2) O _(3) and/or B _(2) O _(3) were synthesized via the modified solid-state reaction method. It was found that Nb ~(5+) -doped and B _(2) O _(3) + Al _(2) O _(3) -coated LMO powders comprising 5 μm granular agglomerated fine primary particles smaller than 350 nm in diameter exhibited superior electrochemical properties with initial discharge capacity of 101.68 mA h g ~(?1) ; we also observed capacity retention of 96.31% after 300 cycles at room temperature (RT) and that of 98% after 50 cycles at 55 °C and 1C rate.