Liu Xu, Wang Lei, Yu Peng, Tian Chungui, Sun Fanfei, Ma Jingyuan, Li Wei, Fu Honggang
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin, 150080, China.
Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201204, China.
Angew Chem Int Ed Engl. 2018 Dec 3;57(49):16166-16170. doi: 10.1002/anie.201809009. Epub 2018 Nov 12.
Low-cost, efficient bifunctional electrocatalysts are needed to mediate the oxygen reduction and oxygen evolution reactions (ORR/OER) in Zn-air batteries. Such catalysts should offer binary active sites and an ability to transfer oxygen-based species and electrons. A 3D catalyst, composed of nanoparticles of CoFe alloy embedded in N-doped carbon nanotubes tangled with reduced graphene oxide, was developed, which presents appreciable ORR/OER activity when applied in a Zn-air battery. A high open-circuit voltage of 1.43 V, a stable discharge voltage of 1.22 V, a high energy efficiency of 60.1 %, and excellent stability after 1 600 cycles at 10 mA cm are demonstrated. An all-solid-state battery had an outstanding lifetime and high cell efficiency even upon bending. In situ X-ray absorption spectroscopy revealed that OOH* and O* intermediates induce variations in the Fe-Fe and Co-Co bond lengths, respectively, suggesting that Fe and Co species are crucial to the ORR/OER processes.
锌空气电池中需要低成本、高效的双功能电催化剂来介导氧还原反应和析氧反应（ORR/OER）。这类催化剂应具备二元活性位点以及转移氧基物种和电子的能力。开发了一种三维催化剂，它由嵌入在与还原氧化石墨烯缠结的氮掺杂碳纳米管中的钴铁合金纳米颗粒组成，在应用于锌空气电池时表现出可观的ORR/OER活性。展示了1.43 V的高开路电压、1.22 V的稳定放电电压、60.1%的高能效以及在10 mA cm下经过1600次循环后的优异稳定性。全固态电池即使在弯曲时也具有出色的寿命和高电池效率。原位X射线吸收光谱表明，OOH和O中间体分别导致Fe-Fe和Co-Co键长发生变化，这表明Fe和Co物种对ORR/OER过程至关重要。
