An Effectively Activated Hierarchical Nano‐/Microspherical Li 1.2 Ni 0.2 Mn 0.6 O 2 Cathode for Long‐Life and High‐Rate Lithium‐Ion Batteries

Rechargeable lithium‐ion batteries with high energy and high power density are required in the application of electric vehicles and portable electronics. Herein, we introduce a type of spherical Li‐rich cathode material, Li 1.2 Ni 0.2 Mn 0.6 O 2 , assembled from uniform nanocubes by a facile polyvinylpyrrolidone (PVP)‐assisted hydrothermal method. The material with a hierarchical nano‐/microstructure exhibits stable high‐rate performance. Furthermore, the precipitant (i.e., urea) and the structure‐directing agent (i.e., PVP) effectively activated the Li 2 MnO 3 components in the microscale material to achieve a high specific capacity of 298.5 mAh g −1 in the first cycle. This Li‐rich cathode material still delivered 243 mAh g −1 at 0.1 C after 200 cycles and the capacity retentions at 0.5, 1, 2, and 5 C were 94.4, 78.7, 76.3, and 67.8 % after 150 cycles, respectively. The results make this Li‐rich nano‐/microstructure a promising cathode material for long‐life and high‐performance lithium‐ion batteries.