Self-assembled hierarchical porous NiMn2O4 microspheres as high performance Li-ion battery anodes.

ABSTRACT

Hierarchical structured porous NiMn2O4 microspheres assembled with nanorods are synthesized through a simple hydrothermal method followed by calcination in air. As anode materials for lithium ion batteries (LIBs), the NiMn2O4 microspheres exhibit a high specific capacity. The initial discharge capacity is 1126 mA h g-1. After 1000 cycles, the NiMn2O4 demonstrates a reversible capacity of 900 mA h g-1 at a current density of 500 mA g-1. In particular, the porous NiMn2O4 microspheres still could deliver a remarkable discharge capacity of 490 mA h g-1 even at a high current density of 2 A g-1, indicating their potential application in Li-ion batteries. This excellent electrochemical performance is ascribed to the unique hierarchical porous structure which can provide sufficient contact for the transfer of Li+ ion and area for the volume change of the electrolyte leading to enhanced Li+ mobility.