This suggests that cell degradation due to extensive cycling has resulted in formation of a Li-deficient LO phase. Alternatively, there may have been a loss of Li during formation of the anode SEI or Li loss during the leaching process. Rietveld refinement analysis using the XRD data shows a decrease in the wt% of the LMO phase which is accompanied by an increase in the wt% of the LO phase with leaching time highlighting the selective nature of the leaching process (Figure ). The leaching process does not appear to have any significant impact upon the lattice parameters of either phase (Table and Figure ).