Multi-shelled porous LiNi0.5Mn1.5O4 microspheres as a 5 V cathode material for lithium-ion batteries

• Multi-shelled LiNi0.5Mn1.5O4 microspheres were prepared by a co-precipitation method.
• The formation mechanism of multi-shelled LiNi0.5Mn1.5O4 microspheres was illustrated.
• Multi-shelled LiNi0.5Mn1.5O4 microspheres exhibited good electrochemical performances.

Multi-shelled porous LiNi0.5Mn1.5O4 microspheres have been successfully synthesized by a co-precipitation approach combined with high-temperature calcinations. The compositions and structures of multi-shelled LiNi0.5Mn1.5O4 microspheres have been investigated by a variety of characterization methods. The LiNi0.5Mn1.5O4 microspheres are composed of a lot of concentric circular porous shells with constant O, Mn, and Ni concentration, which is ascribed to the fast outward diffusion of Mn and Ni atoms and the slow inward diffusion of O and Li atoms during the calcination process. Electrochemical measurements show that LiNi0.5Mn1.5O4 microspheres deliver good cycling stability and rate capability with discharge capacities of 137.1 (0.1 C), 133.9 (0.2 C), 124.2 (0.5 C), 114.9 (1 C), and 96.0 mAh g−1 (2 C). The LiNi0.5Mn1.5O4 microspheres synthesized by the facile method may be a promising cathode candidate for high energy density lithium-ion batteries.