High energy mechano-chemical milling: Convenient approach to synthesis of LiMn1.5Ni0.5O4 high voltage cathode for lithium ion batteries

The high voltage spinel form of LiMn1.5Ni0.5O4 (LMNO) with a particle size ∼10–40 nm has been synthesized for the first time using high energy mechanical milling (HEMM) followed by low temperature thermal treatments using Li2O, MnO2 and NiO as the starting precursors. The nanostructured LMNO cathode, synthesized by the simple, but effective HEMM process followed by thermal treatments to refine the structure in the temperature range ∼573–1073 K, exhibits a reversible capacity ∼120–110 mAh/g when cycled at a rate of ∼20 mA/g in the potential window ∼3.6–5.1 V. The electrochemical results are comparable to capacity values reported in the literature for LMNO derived using various other methods suggesting the efficacy of HEMM as an attractive and viable alternative approach for synthesizing battery grade high voltage spinel phase, LMNO.