Nitrogen-enriched, double-shelled carbon/layered double hydroxide hollow microspheres for excellent electrochemical performance.
Nitrogen-enriched, double-shelled carbon/layered double hydroxide hollow microspheres for excellent electrochemical performance.
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DOI：
10.1039/c4nr02756f
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发表时间：
2014-08
期刊：
影响因子：
6.7
通讯作者：
Jie Xu;Fei He;S. Gai;Shenghuan Zhang;Lei Li;Piaoping Yang
中科院分区：
文献类型：
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作者：
Jie Xu;Fei He;S. Gai;Shenghuan Zhang;Lei Li;Piaoping Yang
一种独特的，双壳，中空，碳基复合材料与丰富的氮已通过一个简单的和多功能的合成策略制备。分层复合材料采用富氮碳空心球作为内壳和交叉Ni/Al层状双氢氧化物（LDH）纳米片作为外壳。所得N-C@LDH中空微球（HMS）具有高氮富集、大比表面积（337 m2 g-1）和均匀开放的介孔结构。利用这些特性，该复合材料表现出明显优于无氮碳@LDH复合材料和无碳壳中空LDH的上级电容行为，包括高的比电容、优异的倍率性能和良好的循环稳定性。在1A·g（-1）的电流密度下，复合材料的比电容为1711.51F·g（-1）。特别地，在10A g（-1）的高电流密度下，高比电容可以保持为997.3F g（-1），在该高电流密度下500次循环后，其仍保持初始比电容的94.97%。这种富含氮的中空碳/LDH复合材料由于其高的电化学性能，可以预期是一种有前途的电化学电容器电极材料。
A unique, double-shelled, hollow, carbon-based composite with enriched nitrogen has been prepared through a facile and versatile synthetic strategy. The hierarchical composite employs the nitrogen-enriched carbon hollow sphere as an interior shell and intercrossed Ni/Al layered double hydroxide (LDH) nanosheets as an exterior shell. The obtained N-C@LDH hollow microspheres (HMS) have high nitrogen enrichment, large specific surface area (337 m(2) g(-1)), and uniform and open mesoporous structure. Taking advantage of these characteristics, the composite exhibits obviously superior capacitive behavior, including high specific capacitance, excellent rate capability and good cycling stability, compared with nitrogen-free carbon@LDH composite and hollow LDH without carbon shell. The composite displays high specific capacitance of 1711.51 F g(-1) at a current density of 1 A g(-1). In particular, the high specific capacitance can be kept to 997.3 F g(-1) at a high current density of 10 A g(-1), which still retains 94.97% of the initial specific capacitance after 500 cycles at this high current density. This N-enriched, hollow carbon/LDH composite can be expected to be a promising electrode material for electrochemical capacitors due to its high electrochemical performance.