Fabrication of Mesoporous Graphene@Ag@TiO2 Composite Nanofibers Via Electrospinning as Anode Materials for High-Performance Li-Ion Batteries

Nanosized TiO 2 has been actively developed as a low-cost and environment-friendly anode material for lithium-ion batteries (LIBs), but its poor electronic conductivity seriously restricts its practical applications. This drawback is addressed in this work by the fabrication of one-dimensional mesoporous graphene@Ag@TiO 2 composite nanofibers as anode materials for high-performance LIBs. The materials were prepared via electrospinning combined with annealing treatment, and the effects of graphene addition on the microstructure and electrochemical performance of the resulting mesoporous graphene@Ag@TiO 2 nanofibers were investigated in detail. Ag@TiO 2 nanofibers with the optimal amount of graphene displayed a maximum initial discharge capacity of 4 9 0 . 5 mAh ⋅ g − 1 at 1 0 0 mA ⋅ g − 1 and retained a discharge capacity of 2 0 9 . 1 mAh ⋅ g − 1 at 1 0 0 mA ⋅ g − 1 after 100 cycles. These results reflect the excellent cycling stability of the material. The average specific discharge capacity of the nanofibers ( 9 7 . 6 mAh ⋅ g − 1 at 1 0 0 0 mA ⋅ g − 1 ) was two-fold higher than that of samples without graphene, and their discharge capacity returned to 2 5 3 . 8 mA ⋅ g − 1 (approximately 9 6 . 2 mA ⋅ g − 1 for other nanofibers) when the current density was recovered to the initial value ( 4 0 mA ⋅ g − 1 ) . Electrochemical impedance spectroscopic measurements confirmed that the conductivity of the electrode was 6 . 3 × 1 0 − 1 S ⋅ cm − 1 , which is higher than that of bare mesoporous Ag@TiO 2 ( 1 . 9 9 × 1 0 − 5 S ⋅ cm − 1 ). Thus, one-dimensional mesoporous graphene@Ag@TiO 2 nanofibers can be regarded as a promising anode material for LIBs.