In situ phase behaviour of a high capacity LiCoPO4 electrode during constant or pulsed charge of a lithium cell

Abstract

The phase changes that occur during lithium extraction from LiCoPO₄ 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 LiCoPO₄, Li_2/3CoPO₄ and CoPO₄ resulted in unit cell volume variations. On current pulsing, lattice parameter shifts and phase recovery were directly observed.