Hetero-structured NiS2/CoS2 nanospheres embedded on N/S co-doped carbon nanocages with ultra-thin nanosheets for hybrid supercapacitors
Hetero-structured NiS2/CoS2 nanospheres embedded on N/S co-doped carbon nanocages with ultra-thin nanosheets for hybrid supercapacitors
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DOI：
10.1016/j.electacta.2022.140604
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发表时间：
2022-05
影响因子：
6.6
通讯作者：
Shanshan Li;Yuan Yang;Zhi-Biao Hu;Shuo Li;Fei Ding;Xinxin Xiao;P. Si;J. Ulstrup
中科院分区：
文献类型：
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作者：
Shanshan Li;Yuan Yang;Zhi-Biao Hu;Shuo Li;Fei Ding;Xinxin Xiao;P. Si;J. Ulstrup
过渡金属硫化物具有较高的导电性和电化学活性，是一种很有前途的复合超级电容器正极材料。然而，考虑到它们较差的循环寿命和速率性能，关键的挑战仍然存在。在这篇文章中，我们描述了通过逐步蚀刻，退火和硫化ZIF-67获得的中空NiS2/CoS2@C复合材料。具体来说，NiS2/ cos2颗粒分散在N/S共掺杂的碳纳米笼上，表现出优异的稳定性和速率性能。N/S共掺杂碳独特的纳米笼结构和nis2和cos2的非均相界面可以促进离子传递和电子转移，丰富活性位点，增强反应活性。NiS2/CoS2@C纳米笼复合材料表现出相当好的电化学性能，比容量为1373 C g-1at 1a g-1。当与还原氧化石墨烯（RGO）负极结合时，组装的混合超级电容器在功率密度为800 W kg-1时的能量密度为63.3 Wh kg-1，即使在13,000次循环后仍保持超过98%的初始容量。
Featuring high electrical conductivity and electrochemical activity, transition metal sulfides are promising materials for the positive electrode of hybrid supercapacitors. However, considering their poor cycling life and rate performance, critical challenges remain. In this contribution, we describe hollow NiS2/CoS2@C composites obtained by stepwise etching, annealing, and sulfuration of ZIF-67. Specifically, NiS2/CoS2particles were dispersed on N/S co-doped carbon nanocages and found to exhibit outstanding stability and rate performance. The unique nanocage structure of N/S co-doped carbon and heterogeneous interfaces of NiS2and CoS2can promote both ion transport and electron transfer, enriching the active site for enhanced reactivity. The resulting NiS2/CoS2@C nanocage composites in fact showed considerable electrochemical performance, with a specific capacity of 1373 C g-1at 1 A g-1. When combined with reduced graphene oxide (RGO)-based negative electrode, the assembled hybrid supercapacitor registered an energy density of 63.3 Wh kg-1at a power density of 800 W kg-1, retaining exceeding 98% of the initial capacity even after 13,000 cycles.