Investigating of carbon nanofiber-supported PtSn nanowires and their application in Li-O2 battery

Abstract

In this study, we successfully designed and synthesized the nanorods of PtSn on carbon nanofiber (CNF) surface with interconnected pores for high-performance Li-O₂ battery cathodes. The CNF were prepared by electrospinning the solution of PAN polymer, followed by carbonization process. The CNF exhibited the uniform 1-D structure with diameter of 300 nm and interconnected pore of 2-4 µm. Subsequently, PtSn nanorods (PtNRs) are grown on the CNF surface (CNF@PtSn NWsNWs ) as catalysts in order to enhance the performance of Li–O₂ battery using the cathodes. Especially, a Li–O₂ cell using the CNF@PtSn NWsNWs  cathode exhibits higher electrochemical performance in terms of rate capability, energy efficiency as well as cycle stability. We have proved that the growth of PtNRs results in the formation of poorly crystalline Li₂O₂, which can significantly reduce overpotentials both during a discharge and a charge. It also contributes to considerably prolonged cycle life of a Li–O₂ cell using the CNF@PtSn NWsNWs  (165 cycles) in comparison to a cell using the CNF cathode (73 cycles) with limiting capacity of 1000 mAh/g_c at a current density of 500 mA/g_c.