Electrochemical Na-deintercalation from NaVO2
Résumé
This paper describes the preparation of NaxVO2 phases by means of electrochemical deintercalation. The curves V = f(x) show that the process is reversible up to x = 0.5 and they indicate the presence of multiple single phase domains in the range 1 < x < 0.5. Two single phases have been successfully isolated for Na1/2VO2 and Na2/3VO2 compositions; we report here the first X-ray powder diffraction measurements of these phases. They present a O'3-type monoclinic distortion of the O3 rhombohedral phase observed for Na1VO2. The evolution of cell parameters with sodium deintercalation is comparable with other AxMO2 layered oxides.