Reactive molten salt synthesis of natural graphite flakes decorated with SnO2 nanorods as high performance, low cost anode material for lithium ion batteries

Abstract

The fabrication of hybrid materials, such as SnO2-C, applicable in advanced energy storage systems, often suffers from lack of simplicity, scalability, cost effectiveness and/or sustainability. Therefore, the development of simpler and more efficient technologies for the sustainable production of energy materials with decent performance is highly desirable. In the current investigation, a hybrid nanostructured powder comprising of natural graphite flakes decorated with SnO2 single crystalline nanorods (NG-SnO2) was synthesized by a facile, rapid and cost effective one-step molten salt method, and characterized by a variety of techniques including X-ray diffraction, Raman spectroscopy, thermal analysis and electron microscopy. A perfect connection was identified between SnO2 nanorods and few-layers graphite on the surface of flakes. This hybrid material exhibited an excellent electrochemical performance as the anode material for Li-ion batteries, delivering a reversible capacity of 495 mAhg−1 after 500 cycles. The few-layered graphite substrate could successfully promote the electron transfer kinetics and also buffers the mechanical stress caused by the lithiation-delithiation of perfectly attached SnO2 nanorods during the battery cycling. The molten salt process discussed here provides a cost-effective and scalable strategy for rapid preparation of the hybrid nanostructured anode material, utilizing the low cost and abundant natural graphite.