Preparation of Li1.2Ni0.2Mn0.6O2 hollow stratified sphere by self-template method and surface vulcanization

Abstract

As promising cathode materials in Li-ion batteries, Li-rich layered oxides still suffer from unsatisfactory first Coulomb efficiency and cyclic stability. Herein, the hollow structure of Li1.2Mn0.6Ni0.2O2 was purposefully designed by a self-template method with MnO2 as the precursor. Then, the Ni-Mn sulfides coated layers was formed on the surface of the material by avulcanization with thioacetamide. It is proved that the Ni-Mn sulfides are evenly distributed on the surface, and the vulcanization process enlarges the internal hollow volume, which greatly improved the electrochemical performance of cathode materials. The optimal sample was delivered an initial discharge specific capacities of 270.2 mA h g−1 with highest coulomb efficiency (79.3 %) and remarkable cycling stability of 95.6% capacity retention after 100 cycles at 0.1C.