  The structure of a new member of the AxCoO2 x nH2O family (A=Li,Na,K) was
determined by high-resolution synchrotron X-ray powder diffraction. Layered
lithium cobalt oxide hydrate LixCoO2 x 2H2O crystallizes in a disordered
monoclinic structure (space group C2/m) with lattice parameters a = 4.8915(2)
A, b = 2.8239(1) A, c = 10.7033(9) A, beta = 112.386(4)deg. Unlike the
superconducting sodium cobalt oxide hydrate, this material possesses a
structure with lithium-water layers intercalated between disordered octahedral
sheets of cobalt oxide. The interlayer spacing is slightly larger (~0.9%) due
to the higher water content, and one of the two lithium sites extends into the
water layer. This material shows no superconducting transition above 2K.
