Simultaneous Electrospinning and Electrospraying: Fabrication of a Carbon Nanofibre/MnO/Reduced Graphene Oxide Thin Film as a High-Performance Anode for Lithium-Ion Batteries

摘要

Rational fabrication of flexible thin-film electrodes with superior electrochemical performance is challenging now in consumer electronics miniaturization. In this work, we combine electro-spinning with electrospraying in a simultaneous process to achieve the CNFs/MnO/rGO composite film electrodes (CNFs= carbon nanofibres; rGO= reduced graphene oxide) for lithiumion batteries. For the as-obtained thin-film electrode, the 2D reduced graphene sheets are dispersed on each of the 1D CNFs/MnO composite filaments, in which the nanofibres and rGO nanosheets can form interconnected morphologies simultaneously. The thin-film electrodes with enhanced electrical conductivity and flexibility could efficiently accommodate the volume changes of MnO particles by the very elastic buffer space. As expected, the composite electrode exhibits a high discharge capacity of 1118 mAhg(-1) at 0.1 Ag-1, and then back to 0.1 Ag-1 after 80 cycles, the capacity retention is still up to 98%; at high rates (e.g. 5 Ag-1), the composite is still able to maintain a high reversible capacity of 574 mAhg(-1) after 3000 cycles with a significant Coulombic efficiency of 99%. This is the best specific capacity at 5 Ag-1 and longest cycling life reported for MnO thin-film anodes. In addition, the technique provides a facile path to combine 1D fibres/2D nanosheets layer-by-layer in a composite film with tunable fibre diameter. This is the first time that the fabrication of 1D CNFs/MnO fibres and 2D rGO sheet network film electrodes via simultaneous electrospinning and electrospraying methods has been reported.