Electrospun CuFe₂O₄ nanotubes as anodes for high-performance lithium-ion batteries

Herein, we report on the synthesis and lithium storage properties of electrospun one-dimensional (1D) CuFe₂O₄ nanomaterials. 1D CuFe₂O₄ nanotubes and nanorods were fabricated by a single spinneret electrospinning method followed by thermal decomposition for removal of polymers from the precursor fibers. The as-prepared CuFe ₂O₄ nanotubes with wall thickness of ∼50 nm presented diameters of ·∼150 nm and lengths up to several millimeters. It was found that phase separation between the electrospun composite materials occured during the electrospinning process, while the as-spun precursor nanofibers composed of polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP) and metal salts might possess a core-shell structure (PAN as the core and PVP/metal salts composite as the shell) and then transformed to a hollow structure after calcination. Moreover, as a demonstration of the functional properties of the 1D nanostructure, CuFe₂O₄ nanotubes and nanorods were investigated as anodes for lithium ion batteries (LIBs). It was demonstrated that CuFe₂O₄ nanotubes not only delivered a high reversible capacity of ∼816 mAh·g^-1 at a current density of 200 mA·g^-1 over 50 cycles, but also showed superior rate capability with respect to counterpart nanorods. Probably, the enhanced electrochemical performance can be attributed to its high specific surface areas as well as the unique hollow structure.