Vertical graphene nanosheetsmodified Al current collectors for high-performance sodium-ion batteries

Rechargeable sodium-ion batteries (SIBs) are promising candidates for large-scale energy storage owing to their excellent high-power performance. However, Al-based current collectorsat both anodes and cathodes of SIBs, which widely influence the power properties of a variety of electrodes in SIBs, have rarely been investigated. Here, we demonstrate that vertical graphene nanosheets grown on commercial Al foil by the plasma-enhanced chemical vapor deposition (PECVD) method, form a robust connection with the carbon-based conductive network of the electrode, thereby significantly reducing the electrode-current collector interfacial resistance. For sodium vanadium phosphate (NVP) anodes with vertical graphenenanosheetmodified Al foil (G-Al) current collectors, the interfacial resistance between the electrode and current collector is reduced 20-fold compared with that in the case of Al foil. The G-Al current collector reduces the polarization and improves the rate capability compared with that of Al current collectors within both cathodes and anodes of SIBs. At a high rate of 5 C, the capacity retention of NVP cathode with G-Al current collector is 74%, which is much higher than that with Al foil (22%).We believe that the obtained results support the prospect for the widespread use of G-Al current collectors in the further improvement of high-power profiles of SIBs.