Alkali Etched Nanoporous Silicon Graphene Composite as Sodium Ion Battery Anode

Abstract

A simple and fast method is used for the preparation of nano-porous silicon (Si) and porous silicon-graphene composites (Si-G) as an anode material for the application of sodium-ion batteries. The fabrication method includes the ball milling technique for mixing the silicon powder and graphene for five minutes with an alkaline etching solution. The produced nano powder is characterized using energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), scanning/transmission electron microscope (SEM/TEM), and Raman spectroscopy for investigating their composition, morphology, and structural properties. The amount of the oxidized silicon (silica) is about four times in graphene-containing sample indicating catalytic power of high surface area carbon. Also, Si-G nanocomposite is characterized by the presence of sodium residues that might be strongly adsorbed to carbon. The reversible capacities reported for Si and Si-G samples are 15.7 and 84 mAhg -1 respectively. The columbic efficiencies for those samples are 7% and 40%. The EIS shows a remarkable reduction in RCT value for Si-G anodes and increases in its ionic conductivity.

Ultra-fast green microwave assisted synthesis of NaFePO4-C nanocomposites for sodium ion batteries and supercapacitors

“…On the other hand, sodium is environmentally friendly and its abundance in the earth's crust is about 1350 times more than that of lithium 4 . Many nanomaterials have been revealed as cathodes and anodes for sodium ion batteries (SIBs) and have been published elsewhere [5][6][7][8] . Sodium vanadium phosphates (NVP) Na 3 V 2 (PO 4 ) 3 and Na 3 VCr(PO 4 ) 3 with NASICON structures were among the most successful active cathode materials owing to their high and flat discharge potential at 3.4 V vs Na/Na + , which maximizes energy density.…”