The electrode material is found to consist of a mixture of Rm and C2/m space-group symmetry components in a weight ration of approximately 4:1. Doping with ~ 2% Cr and 5% F was successful in the main layered phase with Rm space-group, with Cr residing at the 3a transition-metal site and F residing at the 6c oxygen site, as supported by neutron and X-ray powder diffraction as well as electron microscopy.

The electrochemical performance of the doped and undoped materials were compared in coin cells against lithium metal, allowing the comparison of capacity and rate performance, as well as lithium ion diffusion constants within the material as derived from cyclic voltammetry. These differences in measured electrochemical performance were reconciled with the results of structural studies of the electrode powders, as well as differences in the change of these structures that occurred during operation in full 18650 cells against Li₄Ti₅O₁₂, as measured using in operando neutron powder diffraction.

[1] W.K. Pang, H.F. Lin, V.K. Peterson, C.Z. Lu, C.E. Liu, S.C. Liao, J.M. Chen “Effects of fluorine and chromium doping on the performance of lithium-rich Li_{1+ x}MO₂ (M= Ni, Mn, Co) positive electrodes” Chem. Mater. 2017.