Electrospun Ultralong Hierarchical Vanadium Oxide Nanowires with High Performance for Lithium Ion Batteries
Electrospun Ultralong Hierarchical Vanadium Oxide Nanowires with High Performance for Lithium Ion Batteries
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DOI：
10.1021/nl103343w
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发表时间：
2010-11-01
期刊：
影响因子：
10.8
通讯作者：
Zhao, Yunlong
中科院分区：
文献类型：
--
作者：
Mai, Liqiang;Xu, Lin;Zhao, Yunlong
采用静电纺丝结合退火的方法，以廉价的起始原料制备了直径为100-200 nm，长度可达数mm的钒氧化物纳米线。分级纳米线由直径约50 nm和长度为100 nm的氧化钒纳米棒连接而成。当锂离子电池在1.75~4.0 V循环时，其首次放电容量和第50次放电容量分别达到390和201 mAh/g;当电池在2.0~4.0 V循环时，其首次放电容量和第50次放电容量分别达到275和187 mAh/g。与水热法合成的自聚集短纳米棒相比，超长分级钒氧化物纳米线具有更高的容量。这是由于这样的事实，即由于纳米棒在超长纳米线中的附着，独特的纳米棒中纳米线结构的自聚集已经大大减少，这可以保持活性材料、导电添加剂和电解质的大的有效接触面积，并充分实现基于纳米材料的阴极的优点。这表明，超长分级钒氧化物纳米线是作为改善锂离子电池循环性能的阴极的最有利的纳米结构之一。
Ultralong hierarchical vanadium oxide nanowires with diameter of 100-200 nm and length up to several millimeters were synthesized using the low-cost starting materials by electrospinning combined with annealing. The hierarchical nanowires were constructed from attached vanadium oxide nanorods of diameter around 50 nm and length of I 00 nm. The initial and 50th discharge capacities of the ultralong hierarchical vanadium oxide nanowire cathodes are up to 390 and 201 mAh/g when the lithium ion battery cycled between 1.75 and 4.0 V. When the battery was cycled between 2.0 and 4.0 V. the initial and 50th discharge capacities of the nanowire cathodes are 275 and 187 mAh/g. Compared with self-aggregated short nanorods synthesized by hydrothermal method, the ultralong hierarchical vanadium oxide nanowires exhibit much higher capacity. This is due to the fact that self-aggregation of the unique nanorod-in-nanowire structures have been greatly reduced because of the attachment of nanorods in the ultralong nanowires, which can keep the effective contact areas of active materials, conductive additives, and electrolyte large and fully realize the advantage of nanomaterial-based cathodes. This demonstrates that ultralong hierarchical vanadium oxide nanowire is one of the most favorable nanostructures as cathodes for improving cycling performance of lithium ion batteries.