148978 20251113150205.0 doi 10.1021/acsaem.2c02123 sideral 142115 ART-2022-142115 eng Villanueva, Nicolás (orcid)0000-0001-9942-9322 Iron Electrodes Based on Sulfur-Modified Iron Oxides with Enhanced Stability for Iron–Air Batteries 2022 Access copy available to the general public Unrestricted Iron–air systems are a very promising technology with the potential to become one of the cheapest and safest energy storage solutions of the future. However, iron anodes still face some challenges like passivation, resulting in loss of capacity, due to the formation of nonconductive species during cycling as well as the hydrogen evolution reaction, a parasitic reaction interfering with the charging of the electrode. In the present work these two issues are addressed: Sulfur-modified mesoporous iron oxides are obtained and used as hot-pressed negative electrodes for alkaline iron–air batteries. Iron electrodes present average capacity values between 400 and 500 mA h g Fe–1 for ∼100 h of operation, the S-modified iron oxides being the most stable ones. An exponential deactivation model fitting the discharge capacity of the different electrodes compared to the number of cycles was proposed. According to the model, the best of the electrodes loses less than 0.5% of its capacity per cycle. Furthermore, doubling the charge and discharge rates allows increasing both the discharge capacity and the Coulumbic efficiency, though at the expense of stability. This manuscript proves that the proper distribution of sulfur on the surface of the iron oxide is fundamental to suppress the HER and passivation, enhancing the stability of the electrode. These properties were further corroborated in long test-runs which comprised more than 400 h of charging and discharging. info:eu-repo/grantAgreement/ES/DGA/T06-20R Grupo de Conversión de Combustibles info:eu-repo/grantAgreement/ES/AEI/IJCI-2017-32354 info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es 6.4 2022 MATERIALS SCIENCE, MULTIDISCIPLINARY 86 / 343 = 0.251 2022 Q2 T1 CHEMISTRY, PHYSICAL 43 / 161 = 0.267 2022 Q2 T1 ENERGY & FUELS 40 / 119 = 0.336 2022 Q2 T2 1.588 2022 Chemical Engineering (miscellaneous) 2022 Q1 Electrical and Electronic Engineering 2022 Q1 Materials Chemistry 2022 Q1 Energy Engineering and Power Technology 2022 Q1 Electrochemistry 2022 Q1 9.5 2022 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Alegre, Cinthia Rubin, Javier Universidad de Zaragoza (orcid)0000-0003-1029-3751 Figueredo-Rodríguez, Horacio A. McKerracher, Rachel D. de León, Carlos Ponce Lázaro, María Jesús 5001 065 Universidad de Zaragoza Dpto. Ciencia Tecnol.Mater.Fl. Área Cienc.Mater. Ingen.Metal. 5, 11 (2022), 13439-13451 ACS app. energy mater. ACS applied energy materials 2574-0962 12916883 http://zaguan.unizar.es/record/148978/files/texto_completo.pdf Versión publicada 3131441 http://zaguan.unizar.es/record/148978/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:148978 articulos driver 2025-11-13-15:00:48 ARTICLE