Nitrogen-enriched graphitic carbon encapsulated Fe3O4/Fe3C/Fe composite derived from EDTA-Fe(III) sodium complex as LiBs anodes with boosted performance

Cubic MnV2O4 fabricated through a facile sol-gel process as an anode material for lithium-ion batteries: morphology and performance evolution

Metal vanadates have been popularly advocated as promising anode materials for lithium-ion batteries (LIBs) benefiting from their high theoretical specific capacity and abundant resources. Given that manganese and vanadium are reasonably economical elements and enjoy assorted redox reactions, they have extensive application prospects in energy storage systems. Here, we synthesized cubic MnV₂O₄ as an anode for LIBs by an efficient sol-gel process. As a result, the MnV₂O₄ electrode delivers distinguished electrochemical performance, including an appealing reversible specific capacity of nearly 1325 mA h g^-1 for 500 cycles at 200 mA g^-1, excellent cycling stability with a capacity of 399 mA h g^-1 up to 500 cycles at 2000 mA g^-1 and a favorable rate capability of 516/410 mA h g^-1 at 1000/2000 mA g^-1 (when the current density recuperates to 200 mA g^-1, the specific capacity still boosts as the number of cycles increases). What's more, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) under various scan rates and scanning electron microscopy (SEM) are executed to ascertain with a greater depth the electrochemical kinetic characteristics and morphology of the MnV₂O₄ electrode in different states. These results make known that MnV₂O₄ is a credible anode material for LIBs, and such a facile and economical synthetic route can be extended to the preparation of other metal vanadate materials.

Electrospun Fe3O4-Sn@Carbon Nanofibers Composite as Efficient Anode Material for Li-Ion Batteries

Nanoscale Fe₃O₄-Sn@CNFs was prepared by loading Fe₃O₄ and Sn nanoparticles onto CNFs synthesized via electrostatic spinning and subsequent thermal treatment by solvothermal reaction, and were used as anode materials for lithium-ion batteries. The prepared anode delivers an excellent reversible specific capacity of 1120 mAh·g^-1 at a current density of 100 mA·g^-1 at the 50th cycle. The recovery rate of the specific capacity (99%) proves the better cycle stability. Fe₃O₄ nanoparticles are uniformly dispersed on the surface of nanofibers with high density, effectively increasing the electrochemical reaction sites, and improving the electrochemical performance of the active material. The rate and cycling performance of the fabricated electrodes were significantly improved because of Sn and Fe₃O₄ loading on CNFs with high electrical conductivity and elasticity.