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Binary transition metal oxides have been attracting extensive attention as promising anode materials for lithium-ion batteries, due to their high theoretical specific capacity, superior rate performance and good cycling stability. Here, loaf-like ZnMn2O4 nanorods with diameters of 80-150 nm and lengths of several micrometers are successfully synthesized by annealing MnOOH nanorods and Zn(OH)2 powders at 700 °C for 2 h. The electrochemical properties of the loaf-like ZnMn2O4 nanorods as an anode material are investigated in terms of their reversible capacity, and cycling performance for lithium ion batteries. The loaf-like ZnMn2O4 nanorods exhibit a reversible capacity of 517 mA h g(-1) at a current density of 500 mA g(-1) after 100 cycles. The reversible capacity of the nanorods still could be kept at 457 mA h g(-1) even at 1000 mA g(-1). The improved electrochemical performance can be ascribed to the one-dimensional shape and the porous structure of the loaf-like ZnMn2O4 nanorods, which offers the electrode convenient electron transport pathways and sufficient void spaces to tolerate the volume change during the Li(+) intercalation. These results suggest the promising potential of the loaf-like ZnMn2O4 nanorods in lithium-ion batteries.

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Hierarchically porous materials are an ideal material platform for constructing high performance Li-ion batteries (LIBs), offering great advantages such as large contact area between the electrode and the electrolyte, fast and flexible transport pathways for the electrolyte ions and the space for buffering the strain caused by repeated Li insertion/extraction. In this work, NiO microspheres with hierarchically porous structures have been synthesized via a facile thermal decomposition method by only using a simple precursor. The superstructures are composed of nanocrystals with high specific surface area, large pore volume, and broad pore size distribution. The electrochemical properties of 3D hierarchical mesoporous NiO microspheres were examined by cyclic voltammetry and galvanostatic charge-discharge studies. The results demonstrate that the as-prepared NiO nanospheres are excellent electrode materials in LIBs with high specific capacity, good retention and rate performance. The 3D hierarchical mesoporous NiO microspheres can retain a reversible capacity of 800.2 mA h g(-1) after 100 cycles at a high current density of 500 mA g(-1).