Core-shell structured Fe2P@TiO2/CNF anode nanocomposite fibers for efficient lithium/sodium-ion storage

Herein, a facile way was reported for fabrication of the anode nanocomposites with efficient lithium/sodium storage and excellent cycling stability. Iron phytate nanoparticles embedded in TiO 2 (IP/TiO 2 ) was prepared by coaxial electrospinning with the aid of PAN and PVP. N, P-doped Fe 2 P@TiO 2 core-shell carbon nanofibers (Fe 2 P@TiO 2 /CNF) was prepared after heat treatment. When Fe 2 P@TiO 2 /CNF were introduced as a self-supporting anode in lithium/sodium-ion batteries, Fe 2 P core supplied high energy density , and N, P-doped carbon fiber could induce the structural defects, facilitate electron transport and improve electrical conductivity . Moreover, TiO 2 shell inhibited volumetric expansion and pulverization of Fe 2 P core and improved the cycling stability of the anode. The Fe 2 P@TiO 2 /CNF electrode exhibited a large reversible capacity (LIB: 1175.7 and SIB: 519.8 mAh g −1 ), excellent cycling ability and outstanding rate performance. As anode in LIBs for Fe 2 P@TiO 2 /CNF, capacitance and diffusion control played important roles in Li + intercalation and deintercalation, simultaneously. When Fe 2 P@TiO 2 /CNF anode was used in SIBs, capacitive control behavior occupied a major role and displayed outstanding electrochemical performance . This work offers a possibility for designing anode nanocomposite with outstanding capacity and cycling stability in lithium/sodium-ion batteries.