Synthesis and morphological characterization of Li-Ti/PVP fibers as precursors for Li4Ti5O12 towards its future use as anode materials in Li-ion fiber batteries by means of Electrospinning

Abstract

The ever-increasing evolution and popularity of electronic devices, in hand with globalization, has led to a highly innovative market, always in movement. Novel applications such as smart textiles, where portable electronics are coupled to fabrics, are expected to become a worldwide trend when they overcome some limitations, especially with the energy storage systems used to power them. It is in this context where a flexible battery with the shape of a fiber is of importance. Electrospinning is a versatile synthesis technique where micro and nano fibers can be obtained. When these fibers are conducted onto a substrate it is possible to produce materials with different characteristics and morphologies. In this work, Li4Ti5O12 (LTO) was synthesized as anode material for li-ion batteries and was further characterized. LTO is attractive as it presents characteristics such as high thermal stability, relatively high volumetric capacity and high cyclability. The synthesis of this material was developed in two steps. First, a precursor solution containing a spinnable polymer, and titanium and lithium salts, which were dissolved in a mixture of solvents, was subjected to a process of electrospinning. Then, the obtained fibers were calcined at temperatures between 650 and 850 °C for 7-10 hours in air or argon. Scanning electron microscopy (SEM) coupled to energy dispersive x-ray spectroscopy (EDS) was used to study its morphology and elemental composition. Meanwhile, thermogravimetric analysis (TGA) was performed to study the thermal stability.