Sonoelectrochemical Nanoarchitectonics of Crystalline Mesoporous Magnetite @ Manganese Oxide Nanocomposite as an Alternate Anode Material for Energy-Storage Applications

Abstract

In this report, the synergetic sonoelectrochemical method was utilized to produce magnetite nanoparticles was doped with MnO2 with the assistance of ultrasound to form nanoarchitectonic magnetic crystals with a mesoporous magnetite @ manganese dioxide (m-Fe3O4@MnO2) hybrid nanostructure. The hybrid nanocomposite was rapidly produced based on the nucleation and growth of pure iron-oxide nanocrystals in the electrochemical system. The nanocomposite was pure, highly amorphous, and mesoporous in nature; the magnetite was spherical in shape, with an average diameter of 45 ± 10 nm and a MnO2-plane length of 420 ± 30 nm. The stability of the pure m-Fe3O4 was enhanced from 89.61 to 94.04% with negligible weight loss after adding manganese dioxide and the stable formation of the hybrid nanostructure. Based on the superior results of the material, it was utilized as an anode material in Li-ion batteries. The m-Fe3O4@MnO2 hybrid nanostructure had a highly active surface area, which enhanced the interfacial interaction between the Li-ion and the metal surface; it delivered 1513 mAh g−1 and 1290 mAh g−1 as the first specific discharge and charge capacity, respectively, with 85% coulombic efficiency, and it showed an excellent cyclic reversibility of 660 mAh g−1 with a coulombic efficiency of almost 99% at current density of 1.0 A g−1.