Synthesis and electrochemical characterization of novel high capacity Si3-xFexN4 anode for rechargeable lithium batteries

摘要

An innovative Si3-xFexN4 compound has been identified as possible anode for rechargeable lithium batteries. The compound was synthesized (ceramic method), characterized (PXRD, SEM), and evaluated for electrochemical performance behavior (charge-discharge). The Si3-xFexN4 anode exhibited higher specific capacity (470 mAh/g) and an acceptable capacity fade (<20%) upon extended cycling. The coulumbic efficiency of the compound was found to be 99% even after 50 cycles. The lower average oxidation number and the higher ionic radius of Fe dopant were believed to restrict the formation of passivating surface film and reduced the capacity fade of Si3-xFexN4 anode upon cycling. (C) 2004 Elsevier B.V. All rights reserved.