NiCo2S4 nanocrystals anchored on nitrogen-doped carbon nanotubes as a highly efficient bifunctional electrocatalyst for rechargeable zinc-air batteries
NiCo2S4 nanocrystals anchored on nitrogen-doped carbon nanotubes as a highly efficient bifunctional electrocatalyst for rechargeable zinc-air batteries
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锚定在氮掺杂碳纳米管上的 NiCo2S4 纳米晶体作为可充电锌空气电池的高效双功能电催化剂
DOI：
10.1016/j.nanoen.2016.12.008
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发表时间：
2017-01-01
期刊：
影响因子：
17.6
通讯作者：
Hu, Wenbin
中科院分区：
文献类型：
--
作者：
Han, Xiaopeng;Wu, Xiaoyu;Hu, Wenbin
低成本、高稳定性、具有贵金属及其合金的氧还原反应(ORR)和析氧反应(OER)活性的电催化剂的缺乏，在很大程度上限制了理论能量输出极高的金属-空气电池的商业化发展。因此，一种新型的无机-纳米碳偶联杂化材料，均匀的NiCo2S4纳米晶固定在掺氮碳纳米管上(NiCo2S4/N-CNT)，已经被开发出来作为一种非常有效的双功能催化剂来促进先进的可充电锌空气电池的缓慢的ORR和OER动力学。研究发现，通过调整金属氨络合物的结构来调节杂化材料中NiCo2S4的晶粒度，可以获得最高的催化活性。优化的NiCo2S4/N-CNT纳米复合材料通过半反应测试显示出非凡的双功能活性，表现出与最先进的碳负载铂(PT/C)相当的ORR活性，以及比RuO2更好的OER能力和更好的耐用性。在可再生锌-空气系统中所产生的电池性能进一步证实了其在催化双重ORR和OER方面的卓越有效的双功能。与著名的商用铂碳和RuO2相比，协同作用的NiCo2S4/N-CNT杂化材料显著降低了充放电极化(类似于0.63V)，提高了能量效率(类似于67.2%)，并在10 mA cm(-2)下将循环能力延长到150次。纳米NiCo2S4纳米晶的尺寸小、分散均匀以及硫化物尖晶石与碳纳米管之间的耦合作用不仅提供了有效的电子转移途径，而且改变了碳纳米管的电子结构，从而促进了氧在放电-充电过程中的电催化作用。
The commercial development of metal-air batteries with remarkably high theoretical energy output is largely limited by the scarcity of low-cost and highly stable electrocatalysts with activities for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) comparable to precious metals and their alloys. Herein, a new inorganic-nanocarbon coupled hybrid, homogeneous NiCo2S4 nanocrystals anchored on nitrogen-doped carbon nanotubes (NiCo2S4/N-CNT), has been developed as an extremely efficient bifunctional catalyst to promote the sluggish ORR and OER kinetics for advanced rechargeable zinc-air battery. It is found that the highest activity is obtained by tailoring the crystal size of NiCo2S4 in the hybrid through tuning the construction of metal ammonia complexes. The optimized NiCo2S4/N-CNT nanocomposite exhibits extraordinary bifunctional activity through half reaction testing, displaying comparable ORR activity to state-of-the-art carbon supported platinum (Pt/C) and superior OER capability to RuO2 as well as much better durability. The resulting battery performance in generative Zn-air system further confirms its superb effective bi-functionality for catalyzing dual ORR and OER. Compared with those of well-known commercial Pt/C and RuO2, the synergetic NiCo2S4/N-CNT hybrid enables significantly reduced charge-discharge polarization (similar to 0.63 V), enlarged energy efficiency (similar to 67.2%) and prolonged cyclability up to 150 cycles at 10 mA cm(-2). The tremendously enhanced electrochemical behaviors arise from favorable factors including small sized, homogenous dispersed novel NiCo2S4 nanocrystals and coupling interaction between sulfide spinels and underlying N-doped CNT network, which not only provides efficient electron transfer pathway but also alters the electronic structure, thus facilitating the oxygen electrocatalysis during the discharge-charge processes.