Synthesis of New Type Core–Shell Li[Li0.21(Ni0.20Co0.16Mn0.58)0.8(Ni0.2Mn0.2)0.2]O2 Spherical Particles as a Positive Electrode for Lithium Secondary Batteries by Coprecipitation

Microscale core–shell-structured Li[Li0.21(Ni0.20Co0.16Mn0.58)0.8(Ni0.2Mn0.2)0.2]O2 powders were prepared by a coprecipitation method. To protect the Li[Li0.2(Ni0.14Co0.14Mn0.52)]O2 core material from structural instability at high voltage, a Li[Li0.2(Ni0.4Mn0.4)]O2 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.