Facile synthesis of loaf-like ZnMn2O4nanorods and their excellent performance in Li-ion batteries

Abstract

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.