SiOx and Si Electrode Materials for Li-Ion and Li-Alloy Air Batteries

Introduction Graphitic carbon with theoretical capacity of 372mAh/g is now commonly used as an anode in commercial Li-ion batteries. However, siliconbased anode materials can replace the graphitic carbon if well optimized. Silicon is an attractive alternative material due to its high gravimetric and volumetric capacity density of 4200 mAh/g and 9800 mAh/mL) by forming the Li4.4Si phase [1-3]. In spite of this advantage, Si-based anodes show numerous problems that prevent the material to be commercialized in Li-ion batteries. A significant capacity fade occurs during cycling and low coulombic efficiency. The performance degrades during the first few cycles due to the large volume change from alloying/de-alloying (chargedischarge) that induces cracks in the micro-size particles and then a failure of electrical contacts. In order to reduce this effect, we have selected the SiOx mixed with graphite. The aim of this work is to study the effect of binders and carbon additives on the performance of the SiOx: graphite anode. We will present some primary data of Si and SiO for Lithium alloy air battery. A movie of in situ SEM during charge-discharge of SiOx will be shown.