Porous Silicon as Nanostructured Anode Material for Lithium Ion Batteries

摘要

Future research and manufacturing developments of energy storage materials necessitate the investigation of novel and scalable lithium ion batteries anodes as well as strategies to improve their performances. Among others, silicon-based anodes are particularly promising because of the high theoretical capacity, material abundance and processability. Some major issues still limit the effective employment of silicon, in particular its large volume expansion in cyclation and low coulombic efficiency. In this manuscript bulk crystalline silicon is nanostructured to form porous silicon (PSi) by controlled HF etching and carbon coated via CVD. Mechanical behavior in respect of porosity has been studied by nanoindentation. Pristine and carbon coated silicon have been characterized in their morphological and chemical properties by SEM, XRD and XPS. Finally, the improvements in electrochemical behavior provided by carbon coating have been proved by cyclic voltammetry and galvanostatic charging/discharging measurements.