Hollow microspheres and nanoparticles MnFe₂O₄ as superior anode materials for lithium ion batteries

The commercialized LIBs employing graphite as anodes currently suffer a series of problems from the safety problem, low theoretical capacity (372 mAh g⁻¹) and bad rate capability. Herein, hollow microspheres MnFe₂O₄ (MFO) and nanoparticles MFO have been synthesized. Compared with the nanoparticles MFO, the hollow microspheres MFO as an anode material with novel structure demonstrate superior electrochemical performance, with large specific reversible capacity (1100 mAh g⁻¹ at the specific current of 0.5 C after 100 cycles), high rate capability (more than 500 mAh g⁻¹ even at 5.0 C) and good cyclability with little fading (1.4 % after 100 cycles). The excellent cycling performance is associated with the hollow microsphere structure with large specific surface areas, which can accommodate the severe mechanism strains and ensure more contact area between active material and electrolyte, thus good for diffusion of electrolyte and provide more reaction sites. This work presents a meaningful way for the preparation of MFO with different morphology as superior alternative anodes for lithium ion batteries.