Structural Design of Anode Materials for Li-ion Batteries

Kurzfassung

Despite commercial success of LIBs for portable electronic devices, their low power density (compared to fossil fuels), and high cost still impede a full market penetration of electric vehicles or of large-scale energy storage systems. To overcome these issues, there has been a noticeable increase in development of alternative anode materials with low cost, enhanced safety, high energy/power density and long-term stability. In recent, the development of metal-based anodes (such as pure metal, metal oxide, and their composite) seems to hold significant promise, but these materials have some serious problems such as volume expansion or low conductivity. Hence, a combination of particle size reduction and carbon coating are regarded as effective ways to enhance anode performance. This work presents our recent efforts to improve the electrochemical properties of LTO and Si-based electrodes as alternative anodes for LIBs. We used a simple sol-gel process for preparing hierarchically porous LTO microspheres coated with carbon. Our investigations also focus on cheap fabrication of silicon (Si) anodes with improved cycle life. Commercial Si powders were processed with a planetary ball mill to alter particle size and structure. The chemical composition, structure, and morphology of hierarchical LTO microspheres and Si-based active materials were characterized by means of x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDX). The electrochemical performances of LTO and Si-based anode, including cycling performances and interface behavior, were also investigated in half cell.