The intercalation of water inter P2-Na-2/3[CoxNi1/3-xMn2/3]O-2 (x = 0, 1/6,
1/3) and T2 or O2 structure Li-2/3[CoxNi1/3-xMn2/3]O-2 (x = 0, 1/6, 1/3) h
as been investigated by X-ray diffraction and thermogravimetric analysis (T
GA), Water san be intercalated into P2-Na-2/3[CoxNi1/3-xMn2/3]O-2 (x = 1/6,
1/3) but not within P2-Na-2/3[Ni1/3Mn2/3]O-2. This difference may be relat
ed to the existence of superlattice ordering of Ni atoms but not Co atoms w
ithin the transition metal layer which apparently induces a very strong int
erlayer interaction and inhibits the uptake of water, Two water-containing
phases of P3-Na-2/3(H2O)(y)[Co1/3Mn2/3]O-2 were found and one. with y appro
ximate to 2/3, could be prepared in pure form, By Rietveld refinement of th
e X-ray diffraction pattern of P2-Na-2/3(H2O)(2/3)[Co1/3Mn2/3]O-2, it can b
e concluded that the compound still exists in the ideal P2 structure (P6(3)
/mmc) with the oxygen atoms of the water molecule located on the 2c site. W
ater cannot be intercalated into the corresponding lithiated phases, Li-2/3
[CoxNi1/3-xMn2/3]O-2 for any value of x that we tested (x = 0, 1/6, 1/3).