Flexible Tin Particle/Carbon Nanofiber Composites for Anode Materials in Lithium-Ion Batteries

摘要

Metallic tin (Sn) material has been widely considered as a promising anode material for high performance lithium-ion batteries (LIBs) due to its high theoretically reversible specific capacity of about 992mAhg~(-1). However, its practical usage in LIBs has been greatly hampered by the extremely large volume change when Sn alloys with Li to form Li_(4.4)Sn during Li~+ insertion/extraction cycles, which leads to pulverization of the electrode and very rapid capacity fading [1]. To overcome this problem, one effective strategy has been proposed to use active Sn material/carbon nanofiber composites, in which the carbon nanofiber acts as both electronic conductor and physical buffer to efficiently accommodate the large volume variation during Li~+ insertion/extraction [2]. In this work, a novel flexible nano-sized Sn particles dispersed carbon nanofiber (Sn/CNF) composite as an anode material for LIBs has been prepared by using electrospinning techniques and heating treatment. Amorphous and crystalline nano-sized Sn/CNF composites were obtained by changing preparation conditions. The electrochemical performance results of the amorphous Sn/CNF composite show a higher capacity and more superior cycling stability than the crystalline Sn/CNFs anode material.