In situ phase behaviour of a high capacity LiCoPO electrode during constant or pulsed charge of a lithium cell.

The phase changes that occur during lithium extraction from LiCoPO in lithium half-cells were studied using synchrotron X-ray diffraction. The existence of two two-phase regions with an intermediate phase present was observed. Significant variations in the composition of the phases of nominal stoichiometry LiCoPO, LiCoPO and CoPO resulted in unit cell volume variations. On current pulsing, lattice parameter shifts and phase recovery were directly observed.