A sponge network-shaped Mn3O4/C anode derived from a simple, one-pot metal organic framework-combustion technique for improved lithium ion storage

Abstract

A sponge network-shaped Mn₃O₄ material is synthesized by a one-pot metal organic framework-combustion (MOF-C) technique for Li-ion battery anodes with improved performance. The as-synthesized ordered sponge network morphology is characterized by various techniques, such as powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and N₂ adsorption–desorption measurements. The one-pot synthesized Mn₃O₄ material shows a uniform amorphous graphitic carbon coating with few-nanometer thickness on the surface. This anode shows an initial discharge capacity of 1186 mA h g⁻¹ and a reversible capacity of 768 mA h g⁻¹ is maintained at an applied current density of 200 mA g⁻¹ after 100 cycles. Sustained reversible capacities of 651 and 592 mA h g⁻¹ are measured for the other two different current densities of 500 and 700 mA g⁻¹, respectively, after 120 cycles, demonstrating the high stability of the anode. This unique morphology appears to contribute to the significantly high rate performance, as observed from the retained reversible capacity of 155 mA h g⁻¹ at a very high current density of 10 000 mA g⁻¹, which is maintained for the next two subsequent sequences with a notable recovered capacity of 700 mA h g⁻¹ for an intermediate current density of 400 mA g⁻¹ after 175 cycles.