LixCoO2 is used extensively in portable batteries in laptops and mobile phones, but the scarcity of Li means that alternative materials are required. Structurally related NaxCoO2 has excellent electrochemical performance, and greater stability than its Li-ion analogue. Our neutron Laue diffraction measurements on a large single crystal of Na0.8CoO2 reveal fully ordered stripes of tri-vacancy clusters at low temperature that transform to a partially ordered structure just below room temperature, where the sodium ions and vacancies within the stripes become disordered. 23Na NMR measurements suggest that the ions within these stripes become mobile at this temperature. We plan to study the diffusion mechanism using quasi-elastic neutron scattering on LET. The role of the diffusion of ions in the formation of superstructures is of key importance in reversibility during battery cycling.