Facile synthesis of mesoporous Mn3O4 nanotubes and their excellent performance for lithium-ion batteries

Because of the low cost and operating potential, Mn3O4 is highly noticeable among transition metal oxides as an anode material for Li-ion batteries. Here, mesoporous Mn3O4 nanotubes with a high surface area of 42.18 m(2) g(-1) and an average pore size of 3.72 nm were synthesized for the first time through the hydrogen reduction of beta-MnO2 nanotubes under a H-2/Ar atmosphere at 280 degrees C for 3 h. Electrochemical results demonstrate that the reversible capacity of mesoporous Mn3O4 nanotubes is 641 mA h g(-1) (much higher than the theoretical capacity of graphite, similar to 372 mA h g(-1)) after 100 cycles at a high current density of 500 mA g(-1). The superior electrochemical performance can be attributed to the unique 1D mesoporous nano-tubular structure, which offers fast and flexible transport pathways for electrolyte ions, and also provides sufficient free space to buffer the large volume change of anodes based on the conversion reaction during the repeated lithium-ion insertion/extraction. The improved electrochemical performance makes such a mesoporous Mn3O4 tubular structure promising as an anode material for next-generation lithium-ion batteries.