Organic ligand-facilitated in situ exsolution of CoFe alloys over Ba0.5Sr0.5Co0.8Fe0.2O3−δperovskite toward enhanced oxygen electrocatalysis for rechargeable Zn-air batteries
Abstract
Cobalt-based perovskites are promising electrocatalysts for the oxygen evolution/reduction reaction (OER/ORR), while their surface modification with nanoparticles may further improve the performance. In the past, in situ exsolution of a metal (alloy) over a perovskite surface promoted by a H2 atmosphere has been widely applied in developing nanoparticle modified anode materials for solid oxide fuel cells. However, it is a big challenge to apply this strategy for synthesizing cobalt-rich perovskite oxides for oxygen electrocatalysis due to their poor phase stability under a highly reducing atmosphere. Here, we report another strategy of organic ligand-facilitated in situ exsolution under a N2 atmosphere for developing CoFe nanoalloys over Ba0.5Sr0.5Co0.8Fe0.2O3 − δ (BSCF) perovskite as an air electrode for zinc-air batteries (ZABs). The BSCF-CoFe interface, newly generated oxygen vacancies and Co-N-C porous networks provide conduction pathways for oxygen ions and electrons, leading to the enhanced electrochemical bi-functional performance. BSCF/CoFe offers OER activity, while Co-N-C and CoFe contribute to the ORR activity. Interestingly, the exsolved CoFe alloy also considerably promotes the ORR selectivity, leading to a 4e − pathway. Consequently, ZABs integrated with the bi-functional electrocatalyst exhibit a favourable potential gap of 0.835 V at a discharge/charge current density of 5 mA cm − 2, and the cell operates stably without obvious degradation for over 250 h.
RAS ID
54135
Document Type
Journal Article
Date of Publication
2023
School
School of Engineering
Copyright
subscription content
Publisher
Royal Society of Chemistry
Recommended Citation
Arafat, Y., Azhar, M. R., Zhong, Y., O'Hayre, R., Tadé, M. O., & Shao, Z. (2023). Organic ligand-facilitated in situ exsolution of CoFe alloys over Ba0.5Sr0.5Co0.8Fe0.2O3−δperovskite toward enhanced oxygen electrocatalysis for rechargeable Zn-air batteries. DOI: https://doi.org/10.1039/d2ta07104e
Comments
Arafat, Y., Azhar, M. R., Zhong, Y., O'Hayre, R., Tadé, M. O., & Shao, Z. (2023). Organic ligand-facilitated in situ exsolution of CoFe alloys over Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3− δ perovskite toward enhanced oxygen electrocatalysis for rechargeable Zn-air batteries. Journal of Materials Chemistry A, 11(24), 12856-12865.
https://doi.org/10.1039/d2ta07104e