Sulfur-doped cobalt phosphide nanotube arrays for highly stable hybrid supercapacitor
Sulfur-doped cobalt phosphide nanotube arrays for highly stable hybrid supercapacitor
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DOI：
10.1016/j.nanoen.2017.06.042
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发表时间：
2017-09-01
期刊：
影响因子：
17.6
通讯作者：
Wang, John
中科院分区：
文献类型：
--
作者：
Elshahawy, Abdelnaby M.;Guan, Cao;Wang, John
金属磷化物具有良好的导电性能和高容量，是一种很有前途的超级电容器电极材料。然而，它们受到短期循环稳定性的影响。在此，成功地建立了一种有效的硫化策略，以提高金属磷化物的整体电化学性能。详细地，通过与CoP的硫化反应过程开发了在碳布上排列的硫掺杂的CoP纳米管阵列，其可以提供比裸CoP的电化学性能的显著改善。硫掺杂的CoP纳米管阵列不仅表现出比CoP高1.78倍的容量，而且表现出优异的循环稳定性，在10，000次充电和放电循环后保持99%的原始容量，这比单独的CoP好得多。此外，混合超级电容器已被制造使用硫掺杂的CoP作为正极，它可以提供最大的能量密度为39 W h/kg，功率密度为0.8 kW/kg。全电池还显示出优异的循环稳定性，在50，000次循环后保持86.4%的原始电容，这比以前报道的基于金属磷化物的超级电容器要好得多。
Metal phosphides are promising electrode materials for supercapacitors, owing to their conductive properties and high capacity. However, they are suffering from the short term cycling stability. Herein, an efficient sulfidisation strategy is successfully established to improve the overall electrochemical performance of metal phosphides. In detail, sulfur-doped CoP nanotube arrays aligned on carbon cloth are developed through a sulfidisation reaction process with CoP, which can provide significant improvement in electrochemical performance over that of bare CoP. The sulfur-doped CoP nanotube arrays not only show a capacity which is 1.78 times higher than that of CoP, but also demonstrate excellent cycle stability retaining 99% of the original capacity after 10,000 charge and discharge cycles, which is much better than CoP alone. Furthermore, a hybrid supercapacitor has been fabricated using sulfur-doped CoP as the positive electrode, which can deliver a maximum energy density of 39 W h/kg at a power density of 0.8 kW/kg. The full cell also shows excellent cycling stability by maintaining 86.4% of the original capacitance after 50,000 cycles, which is much better than previously reported metal phosphide-based supercapacitors.