共 38 条
Hollow Carbon Nanofiber-Encapsulated Sulfur Cathodes for High Specific Capacity Rechargeable Lithium Batteries
被引:1194
作者:
Zheng, Guangyuan
[2
]
Yang, Yuan
[1
]
Cha, Judy J.
[1
]
Hong, Seung Sae
[3
]
Cui, Yi
[1
,4
]
机构:
[1] Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA
[2] Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA
[3] Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA
[4] SLAC Natl Accelerator Lab, Stanford Inst Mat & Energy Sci, Menlo Pk, CA 94025 USA
关键词:
Hollow carbon nanofiber-encapsulated sulfur;
Li/S batteries;
high specific capacity;
energy storage;
ELECTROCHEMICAL PROPERTIES;
COMPOSITE CATHODE;
STORAGE;
PERFORMANCE;
NANOTUBES;
ELECTRODE;
D O I:
10.1021/nl2027684
中图分类号:
O6 [化学];
学科分类号:
0703 ;
摘要:
Sulfur has a high specific capacity of 1673 mAh/g polysulfides dissolution presents a significant challenge for as lithium battery cathodes, but its rapid capacity fading due to practical applications. Here we report a hollow carbon nanofiber-encapsulated sulfur cathode for effective trapping of polysulfides and demonstrate experimentally high specific capacity and excellent electrochemical cycling of the cells. The hollow carbon nanofiber arrays were fabricated using anodic aluminum oxide (AAO) templates, through thermal carbonization of polystyrene. The AAO template also facilitates sulfur infusion into the hollow fibers and prevents sulfur from coating onto the exterior carbon wall. The high aspect ratio of the carbon nanofibers provides an ideal structure for trapping polysulfides, and the thin carbon wall allows rapid transport of lithium ions. The small dimension of these nanofibers provides a large surface area per unit mass for Li2S deposition during cycling and reduces pulverization of electrode materials due to volumetric expansion. A high specific capacity of about 730 mAh/g was observed at C/5 rate after 150 cycles of charge/discharge. The introduction of LiNO3 additive to the electrolyte was shown to improve the Coulombic efficiency to over 99% at C/5. The results show that the hollow carbon nanofiber-encapsulated sulfur structure could be a promising cathode design for rechargeable Li/S batteries with high specific energy.
引用
收藏
页码:4462 / 4467
页数:6
相关论文