Hierarchically mesoporous carbon nanofiber/Mn3O4 coaxial nanocables as anodes in lithium ion batteries

• CNF/Mn3O4 was prepared via electrospinning and EPD.
• Coaxial CNF/Mn3O4 consisted of bark-like Mn3O4 shell and CNF core.
• CNF/Mn3O4 formed hierarchically mesoporous structure.
• CNF/Mn3O4 represented high reversible capacity due to elastic CNF core.

Carbon nanofiber/Mn3O4 (CNF/Mn3O4) coaxial nanocables with a three-dimensional (3D) structure are prepared for lithium ion batteries by electrophoretic deposition on an electrospun CNF cathode followed by heat treatment in air. The bark-like Mn3O4 shell with a thickness of 30 nm surrounds the CNFs with a diameter of 200 nm; this hierarchically mesoporous Mn3O4 shell consisted of interconnected nanoparticles grows radially toward the CNF core when viewed from the cross-section of the coaxial cables. The charge transfer resistance of the CNF/Mn3O4 is much smaller than that of the Mn3O4 powder, because of (i) the abundant inner spaces provided via the formation of the 3D coaxial core/shell nanocables, (ii) the high electric pathway for the Mn3O4 nanoparticles attained with the 1D CNFs, and (iii) the structural stability obtained through the cushioning effect created by the CNF/Mn3O4 coaxial morphology. These unique characteristics contribute to achieving a high capacity, excellent cyclic stability, and good rate capability. The CNF/Mn3O4 nanocables deliver an initial capacity of 1690 mAh g−1 at a current density of 100  mA g−1 and maintain a high reversible capacity of 760 mAh g−1 even after 50 charge–discharge cycles without showing any obvious decay.