Microscale core-shell-structured Li[Li-0.21(Ni0.20Co0.16-Mn-0.58)(0.8)(Ni0.2Mn0.2)(0.2)]O-2 powders were prepared by a coprecipitation method. To protect the Li[Li-0.2(Ni0.14Co0.14Mn0.52)]O-2 core material from structural instability at high voltage, a Li[Li-0.2(Ni0.4Mn0.4)]O-2 shell, which provides structural and thermal stability, was used to encapsulate the core. Spherical morphologies with monodispersed powders were observed in the cross-sectional images obtained by scanning electron microscopy (SEM). To the best of our knowledge, this is the first report of the synthesis of a Mn-rich core-shell.