The Study of Phenolic Resin-coated Silicon/graphite Composites as Anode Materials for Li-ion Battery
Date Issued
2006
Date
2006
Author(s)
Tsai, Yi-Lin
DOI
zh-TW
Abstract
The purpose of this study focusd on the impact on silicon and graphite embedded in amorphous carbon pyrolyzing from phenolic resin and formed graphite/silicon composites to replace carbonaceous materials as anode for Li-ion battery. The ingredients of composites are graphite, silicon and amorphous carbon caused by heat process. Amorphous carbon pyrolyzed from phenolic resin functions not only surface modification but also an elastic network which prevents active particle-particle interactions and holds silicon steadfastly. The electrochemical characterization of the composites with different amounts of phenolic resin was investigated. The amount of ingredients is the key point in composite and results have been found out that more capacity obtains with 45 wt% phenolic resin contained in composite and amount of silicon cannot be exceeded 10wt%, or the capacity will decay too fast to use commercially. We also added TiN to enhance the conductivity because silicon is one type of semiconductor. 20wt% of TiN additive enhanced the cyclic performance and coulombic efficiency. The capacity retained about 443 mAh/g after 7 cycles.
Depending on XRD, Raman, and XPS analysis, more amorphous carbon decreased the graphitization degree and increased amount of rhombohedral structures in graphite which contributed to decreasing irreversible capacity.
Subjects
酚酫
樹脂
球形石墨
熱裂解
鋰離子二次電池
矽
phenolic resin
silicon
natural graphite
Li-ion battery
Type
thesis