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The Mg-air batteries face limitations with pronounced hydrogen evolution and low anodic utilization efficiency from Mg anodes in conventional NaCl electrolytes. The corrosion performance, surface composition, and discharge properties of commercial purity Mg anodes were thoroughly investigated in KNO3 electrolytes with and without sodium 5-sulfosalicylate and compared to NaCl electrolyte. The addition of sodium 5-sulfosalicylate to KNO3-based electrolyte results in efficient inhibition of H2 evolution, consequently enhancing anodic utilization efficiency to 84% and specific capacity to 1844 mAh/g, compared to NaCl (24% and 534 mAh/g, respectively) under discharge condition of 10 mA/cm2 in half cell. Furthermore, the chelating ability of sodium 5-sulfosalicylate can significantly improve the Mg surface dissolution kinetics and discharge product deposition rate at the Mg anode / electrolyte interface, yielding formation of a thinner discharge layer as confirmed by time-of-flight secondary ion mass spectrometry. The discharge voltage is increased to 1.60 V, compared to 1.35 V in KNO3 at 0.5 mA/cm2 in full cell. However, higher concentration of sodium 5-sulfosalicylate can accelerate Mg anode dissolution, impeding the improvement of anodic utilization efficiency, specific capacity, and energy density. Hence, determining optimal additive concentration and current density is crucial for enhancing the discharge properties of Mg-air batteries and mitigating excessive Mg dissolution in chloride-free electrolytes.

Mg-air batteries have attracted tremendous attention as a potential next-generation power source for portable electronics and e-transportation due to their remarkable high theoretical volumetric energy density, environmental sustainability, and cost-effectiveness. However, the fast hydrogen evolution reaction (HER) in NaCl-based aqueous electrolytes impairs the performance of Mg-air batteries and leads to poor specific capacity, low energy density, and low utilization. Thus, the conventionally used NaCl solute was proposed to be replaced by NaNO3 and acetic acid additive as a corrosion inhibitor, therefore an electrolyte engineering for long-life time Mg-air batteries is reported. The resulting Mg-air batteries based on this optimized electrolyte demonstrate an improved discharge voltage reaching ∼1.8 V for initial 5 h at a current density of 0.5 mA/cm2 and significantly prolonged cells’ operational lifetime to over 360 h, in contrast to only ∼17 h observed in NaCl electrolyte. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry were employed to analyse the composition of surface film and scanning electron microscopy combined with transmission electron microscopy to clarify the morphology changes of the surface layer as a function of acetic acid addition. The thorough studies of chemical composition and morphology of corrosion products have allowed us to elucidate the working mechanism of Mg anode in this optimized electrolyte for Mg-air batteries.

Since October 2019, Plaza Baquedano in Santiago has been the scene of the major events of the Chilean protests. The statue of General Baquedano, which stands in the centre of the square, became a target and an emblem of the popular uprisings. Its numerous reappropriations by protesters, especially in the cyberspace, illustrate a new form of reclamation of public space in the digital age. In this way, the 3D reconstructions of the monument created by the members of the Antes del Olvido collective show an alternative and committed reality of the uprising.

While museums are experiencing their digital conversion, leading to the delocalization from the physical world to the ciberspace of their exhibition halls and their collections, the Centro de Cultura Digital in Mexico presents the opposite situation. Open to the public since 2012, this cultural center located in the heart of the Mexican capital sets itself a double challenge: to host in a hybrid space, both physical and virtual, a pioneering initiative in the region, to think about digital culture from an institutional perspective. Ten years after its inauguration, we propose to study the causes and results of this attempt at relocation.

The electrochemical behavior of low alloyed Fe-Cr steels with 3 and 5% wt. of Cr in neutral Na2SO4 electrolyte combined with a detailed chemical and morphological characterization of these alloys performed by Auger electron spectroscopy, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry and scanning electron microscopy are presented here. The corrosion of low alloyed Fe-Cr steels proceeds in the prepassive range, with the formation of corrosion surface films having a duplex structure with outer iron oxide/hydroxide layer and inner Cr oxide-rich layer. The thickness, composition, and the morphology of the surface films vary as a function of chromium content in the alloy as well as conditions of electrochemical tests (temperature). Even a low chromium content shows a beneficial effect on the corrosion performances of the Fe-Cr steels. The chromium as a more active component than iron of ferrite increases the anodic activity of this phase, which results in a rapid saturation of the surface with the anodic reaction products forming a fine crystalline-like and compact layer of corrosion products. In this way, the chromium acts as a modifier of formation/crystallization of the iron-rich surface film (mainly magnetite) in the prepassive range.

Abstract Three-dimensional (3D) time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging is a promising tool in the analysis of surface modifications of alloy matrix and intermetallic particles induced by localized corrosion due to its good spatial resolution and very high sensitivity to chemical identification especially involving light mass elements like Li. In this paper, ToF-SIMS 3D chemical mapping combined with scanning electron microscopy was performed to study the localized corrosion of Al-Cu-Li alloy (AA2050-T8) in a region around an Al-Cu-Fe-Mn intermetallic particles (IMPs) in 0. 1 M NaCl solution. Initiation of corrosion was locally observed on the IMPs and between IMPs and matrix substrate. Moreover, a modified oxide/hydroxide layer was observed over IMPs compared to the matrix. This new corrosion layer was enriched with chlorides and Cu hydroxides. ToF-SIMS 3D imaging revealed that Li was present over the alloy matrix, while no Li was present over the IMPs in regions where localized corrosion occurred.

• Enhanced performance of Mg-air batteries in KNO₃-based electrolytes with the addition of 5SS. • Inhibition of Mg corrosion and hydrogen evolution reaction in KNO₃-based electrolytes. • Improved discharge potential at various applied current densities with the addition of 5SS into KNO₃-based electrolytes. • Formation of a thinner and ionically conductive surface layer with the addition of 5SS. The Mg-air batteries face limitations with pronounced hydrogen evolution and low anodic utilization efficiency from Mg anodes in conventional NaCl electrolytes. The corrosion performance, surface composition, and discharge properties of commercial purity Mg anodes were thoroughly investigated in KNO 3 electrolytes with and without sodium 5-sulfosalicylate and compared to NaCl electrolyte. The addition of sodium 5-sulfosalicylate to KNO 3 -based electrolyte results in efficient inhibition of H 2 evolution, consequently enhancing anodic utilization efficiency to 84% and specific capacity to 1844 mAh/g, compared to NaCl (24% and 534 mAh/g, respectively) under discharge condition of 10 mA/cm2 in half cell. Furthermore, the chelating ability of sodium 5-sulfosalicylate can significantly improve the Mg surface dissolution kinetics and discharge product deposition rate at the Mg anode / electrolyte interface, yielding formation of a thinner discharge layer as confirmed by time-of-flight secondary ion mass spectrometry. The discharge voltage is increased to 1.60 V, compared to 1.35 V in KNO 3 at 0.5 mA/cm2 in full cell. However, higher concentration of sodium 5-sulfosalicylate can accelerate Mg anode dissolution, impeding the improvement of anodic utilization efficiency, specific capacity, and energy density. Hence, determining optimal additive concentration and current density is crucial for enhancing the discharge properties of Mg-air batteries and mitigating excessive Mg dissolution in chloride-free electrolytes. [Display omitted] [ABSTRACT FROM AUTHOR]