Time-efficient synthesis of MnO₂ encapsulated α-Fe₂O₃ ellipsoids for lithium ion battery applications

Herein, Fe₂O₃ was enlisted as an environmentally benign and inexpensive anode active material. A facile time-efficient synthesis strategy was developed to prepare hematite Fe₂O₃ ellipsoid particles via hydrothermal method. The structural and morphological properties of the prepared materials were characterized using XRD, FE-SEM, HR-Raman, and HR-TEM. The electrochemical properties were investigated using galvanostatic cycling, cyclic voltammetry, and impedance spectrum analysis. To further overcome the drawbacks of α-Fe₂O₃ ellipsoids, a MnO₂ coating was applied. The encapsulated α-Fe₂O₃ ellipsoids exhibited improved electrochemical properties, such as a high specific capacity, high coulombic efficiency, stable cyclic performance, and a high rate capability. The improved electrochemical performance of the ellipsoids could be attributed to the uniform and continuous MnO₂ layer coatings, yielding an enormous advantage through the sustained integrity of nanoparticles, stimulating the electronic conductivity of electrode materials leading to the formation of a thin SEI (Solid Electrolyte Interphase) layer on the electrode surface, and by maintaining the as-formed layer. The obtained results demonstrated MnO₂ encapsulated α-Fe₂O₃ ellipsoid particles as a superior anode material for lithium ion batteries compared to bare α-Fe₂O₃ and commercially available graphite electrodes. - Highlights: • MnO₂@α-Fe₂O₃ composites have been synthesized via time efficient route. • MnO₂ nanoparticles are densely anchored on the α-Fe₂O₃ network. • Electrochemical behaviors of bare α-Fe₂O₃ and MnO₂ encapsulated α-Fe₂O₃ is compared. • Composite MnO₂@α-Fe₂O₃ delivers good specific capacity and cyclic stability.