Carbon-silicon core-shell nanowires as high capacity electrode for lithium ion batteries.
We introduce a novel design of carbon-silicon core-shell nanowires for high power and long life lithium battery electrodes. Amorphous silicon was coated onto carbon nanofibers to form a core-shell structure and the resulted core-shell nanowires showed great performance as anode material. Since carbon has a much smaller capacity compared to silicon, the carbon core experiences less structural stress or damage during lithium cycling and can function as a mechanical support and an efficient electron conducting pathway. These nanowires have a high charge storage capacity of approximately 2000 mAh/g and good cycling life. They also have a high Coulmbic efficiency of 90% for the first cycle and 98-99.6% for the following cycles. A full cell composed of LiCoO(2) cathode and carbon-silicon core-shell nanowire anode is also demonstrated. Significantly, using these core-shell nanowires we have obtained high mass loading and an area capacity of approximately 4 mAh/cm(2), which is comparable to commercial battery values.
Cui
Li-Feng
LF
Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA.
Yang
Yuan
Y
Hsu
Ching-Mei
CM
Cui
Yi
Y
D002244:Carbon / Q000737:chemistry*; D011211:Electric Power Supplies; D004566:Electrodes; D007477:Ions / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D008422:Materials Testing; D036103:Nanotechnology; D053770:Nanowires / Q000737:chemistry*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
D007477:Ions; D002244:Carbon; D008094:Lithium; D012825:Silicon