Preparation and Characterization of Rice Husks-Derived Silicon-Tin/Nitrogen-Doped Reduced Graphene Oxide Nanocomposites as Anode Materials for Lithium-Ion Batteries

Abstract

Silicon (Si) and Tin (Sn) are promising materials for anodes in lithium-ion batteries due to their high theoretical capacity and abundance of Si on earth. Si can be derived from rice husk which is the main agricultural byproduct in Thailand. However, the challenge of using these materials in lithium-ion batteries is the large volume expansion during charge-discharge process which leads to pulverization of electrodes. The effective solution is to combine these metals as composite with carbon supporter. Nitrogen-doped reduced graphene oxide (NrGO) has been used as carbon supporter in this research because of its high surface area, electrical conductivity and rate of electron transfer. To confirm phases of products, X-rays diffraction techniques (XRD) was measured. The results show that there were peaks of Si, Sn and carbon in XRD patterns. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to illustrate the morphology of prepared composites. From SEM and TEM results, there were small-sized particles of Si and Sn dispersed randomly on NrGO sheets. Furthermore, electrochemical properties of these products were measured to confirm their efficiency as anode materials in lithium-ion batteries by coin cell assembly. The prepared composite can deliver the highest initial capacity of 1600 mA h g-1 and expected to use as anode materials in the next generation lithium-ion batteries.