The ion exchange of Li for Na in P2-structure Na-2/3[Ni1/3Mn2/3]O-2 to make T2-structure Li-2/3[Ni1/3Mn2/3]O-2 is studied. Electron micrographs show that the hexagonal plate-like crystal habit is preserved during ion exchange. Ion exchange is successful and equivalent using both molten salts and concentrated Li+-containing aqueous solutions. By controlling the Li:Na ratio in the ion exchange, it is possible to prepare an intermediate phase of approximate composition Li1/3Na1/3[Ni1/3Mn2/3]O-2, where filled alkali layers of Li and Na alternate, thus doubling the c axis of the material. A summary of ion-exchange reactions of Li for Na in other layered Na-bronzes, such as P3-Na-2/3[Ni1/3Mn2/3]O-2, O3-Na[Ni1/2Mn1/2]O-2, P2-Na-2/3[CoxMn1-x]O-2, P3-Na-2/3[CoxMn1-x]O-2, P2-Na2/3CoO2, P2-Na-2/3[Fe1/3Mn2/3]O-2, P2-Na-2/3[Fe2/3Mn1/3]O-2, P2-Na-2/3[Mg1/3Mn2/3]O-2. P2-Na-2/3[Ni1/3Mn2/3]O-2, and O3-NaMnO2, is given.