Selenium@Mesoporous Carbon Composite with Superior Lithium and Sodium Storage Capacity
Selenium@Mesoporous Carbon Composite with Superior Lithium and Sodium Storage Capacity
复制标题
DOI：
10.1021/nn403108w
复制
发表时间：
2013-09-01
期刊：
影响因子：
17.1
通讯作者：
Wang, Chunsheng
中科院分区：
文献类型：
--
作者：
Luo, Chao;Xu, Yunhua;Wang, Chunsheng
在600 ℃真空条件下，将硒注入到介孔炭中，制备了硒浸渍炭复合材料。环状结构的Se-8被制备并被限制在介孔碳中，介孔碳充当电子导电基质。在低成本的LiPF 6/EC/DEC电解液中，多硒化合物在电化学过程中形成了低阶中间体，并被介孔碳稳定，避免了多硒化合物的穿梭反应。Se/介孔碳复合材料在锂离子电池和钠离子电池中均表现出优异的电化学性能。在锂离子电池中，Se-8/介孔碳复合阴极在1000次充/放电循环中提供480 mAh g（-1）的可逆容量，而在Na离子电池中，其提供485 mAh g（-1）的初始容量，并且在380次循环后保持340 mAh g（-1）。Se-8/介孔碳复合材料也表现出优异的倍率性能。当电流密度从0.1增加到5C时，锂离子电池的容量保持约46%，钠离子电池的容量保持约34%。
Selenium-impregnated carbon composites were synthesized by infusing Se into mesoporous carbon at a temperature of 600 degrees C under vacuum. Ring-structured Se-8 was produced and confined in the mesoporous carbon, which acts as an electronic conductive matrix. During the electrochemical process In low-cost LiPF6/EC/DEC electrolyte, low-order polyselenide intermediates formed and were stabilized by mesoporous carbon, which avoided the shuttle reaction of polyselenides. Exceptional electrochemical performance of Se/mesoporous carbon composites was demonstrated in both Li-ion and Na-ion batteries. In lithium-ion batteries, Se-8/mesoporous carbon composite cathodes delivered a reversible capacity of 480 mAh g(-1) for 1000 charge/discharge cycles without any capacity loss, while in Na-ion batteries, it provided initial capacity of 485 mAh g(-1) and retained 340 mAh g(-1) after 380 cycles. The Se-8/mesoporous carbon composites also showed excellent rate capability. As the current density increased from 0.1 to 5 C, the capacity retained about 46% in Li-ion batteries and 34% In Na-ion batteries.