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Ni–Co bimetallic coordination effect for long lifetime rechargeable Zn–air battery
Journal of Energy Chemistry ( IF 13.1 ) Pub Date : 2019-12-12 , DOI: 10.1016/j.jechem.2019.12.005
Mengfei Qiao , Ying Wang , Thomas Wågberg , Xamxikamar Mamat , Xun Hu , Guoan Zou , Guangzhi Hu

The development of bifunctional oxygen electrocatalysts with high efficiency, high stability, and low cost is of great significance to the industrialization of rechargeable Zn–air batteries. A widely accepted view is that the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) follow different catalytic mechanisms, and accordingly they need different active sites for catalysis. Transition metal elements have admirable electronic acceptance ability for coordinating with reactants, and this can weaken the bond energy between reactants, thus promoting the ORR or OER reactions. Herein, the ORR and OER activities of different transition metal supported nitrogen-doped carbon nanotubes were systematically studied and compared. The optimal catalyst for synchronous ORR and OER was obtained by pyrolyzing melamine, cobalt nitrate, and nickel nitrate on carbon nanotubes, called cobalt–nickel supported nitrogen-mixed carbon nanotubes (CoNi–NCNT), which were equipped with two types of high-performance active sites—the Co/Ni–N–C structure for the ORR and CoNi alloy particles for the OER—simultaneously. Remarkably, the optimized CoNi–NCNT exhibited a satisfactory bifunctional catalytic activity for both the ORR and OER. The value of the oxygen electrode activity parameter, ΔE, of CoNi–NCNT was 0.81 V, which surpasses that of catalysts Pt/C and Ir/C, and most of the non-precious metal-based bifunctional electrocatalysts reported in previous literatures. Furthermore, a specially assembled rechargeable Zn–air cell with CoNi–NCNT loaded carbon paper as an air cathode was used to evaluate the practicability. As a result, a superior specific capacity of 744.3 mAh/gZn, a peak power density of 88 mW/cm2, and an excellent rechargeable cycling stability were observed, and these endow the CoNi–NCNT with promising prospects for practical application.



中文翻译:

镍钴双金属配位效应可延长锌空气电池的使用寿命

高效,高稳定性,低成本的双功能氧电催化剂的开发对可充电锌空气电池的产业化具有重要意义。广泛接受的观点是氧还原反应(ORR)和氧释放反应(OER)遵循不同的催化机理,因此它们需要不同的催化活性位点。过渡金属元素具有与反应物配合的令人称赞的电子接受能力,这会削弱反应物之间的键能,从而促进ORR或OER反应。本文对不同过渡金属负载氮掺杂碳纳米管的ORR和OER活性进行了系统的研究和比较。通过三聚氰胺,硝酸钴的热解获得了同步ORR和OER的最佳催化剂。碳纳米管上的硝酸镍和钴-镍负载氮混合碳纳米管(CoNi–NCNT),配备了两种类型的高性能活性位点–用于ORR和CoNi的Co / Ni–N–C结构同时用于OER的合金颗粒。值得注意的是,优化的CoNi-NCNT对ORR和OER均显示出令人满意的双功能催化活性。氧电极活性参数的值ΔCoNi–NCNT的E为0.81 V,超过了催化剂Pt / C和Ir / C,以及先前文献中报道的大多数非贵金属基双功能电催化剂。此外,使用特殊组装的可充电Zn-空气电池,其中装有CoNi-NCNT的复写纸作为空气阴极,用于评估实用性。结果,观察到具有744.3 mAh / g Zn的出色比容量,88 mW / cm 2的峰值功率密度和出色的可充电循环稳定性,这些为CoNi-NCNT的实际应用前景提供了希望。

更新日期:2019-12-12
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