Cathode Properties of xLiF-LiCrO2 Composites (x=0-1.5) Prepared by Dry Ball-Milling Method for Lithium Ion Batteries

The xLiF-LiCrO2 series, prepared using the dry ball-milling method, was investigated to improve the electro-chemical properties of LiCrO2. The addition of LiF to LiCrO2 changed the Cr oxidation state, and its rechargeable capacity increased to greater than that of milled-LiCrO2. The Li-O(F) correlation for xLiF-LiCrO2 was split in two by the dry ball-milling treatment, unlike the case with layered LiCrO2. In addition, the dispersion state of Li and Cr in the particles changed, and part of the Cr oxidation state shifted from +3 to +4 with the addition of LiF to LiCrO2. The reversible capacity increased with increasing x in xLiF-LiCrO2 at x <= 0.7, and the number of reacted electrons increased with increasing x in xLiF-LiCrO2. Cr K-edge and L-edge XANES spectra clarified that the charge-discharge reaction for milled-LiCrO2 and xLiF-LiCrO2 proceeds by only Cr3+/Cr6+ redox couples.

Automated summary

The xLiF-LiCrO2 series, prepared using the dry ball-milling method, showed improved electro-chemical properties compared to milled-LiCrO2. LiF addition changed the oxidation state of Cr, increasing the rechargeable capacity. The dry ball-milling treatment split the Li-O(F) correlation and changed the dispersion state of Li and Cr in the particles. The reversible capacity and the number of reacted electrons increased with the increasing x in xLiF-LiCrO2, and the charge-discharge reaction proceeded through Cr3+/Cr6+ redox couples.