Determining phase transitions of layered oxides via electrochemical and crystallographic analysis

Figures & data

Figure 1. Structure of LiMeO₂, showing metal (Me) octahedra (blue) and positions of oxygen (red) and lithium (green) atoms.

Figure 2. Cyclic voltammogram of NMC. The sharp peaks correspond to the redox couples of the charge compensation reaction.

Figure 3. Measured voltage curves for the 10th and 11th charge (left) and discharge (right) pulses of synthesized NMC from the GITT measurement.

Figure 4. Open-circuit voltage (OCV) of NMC at different lithiation states.

Figure 5. Calculated chemical diffusion coefficient in NMC over the OCV during charging and discharging.

Figure 6. Unit cell parameter variation of NMC cathodes, derived from Rietveld refinement of ex situ XRD patterns. [a] a and c-axis, [b] unit cell volume, both vs. open-circuit voltage (estimated standard deviations are smaller than the symbols used) and [c] detail of diffraction profiles for NMC cathodes showing the characteristic [003] peak.