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While investigating the influence of an alloying element on the corrosion properties of a metal, materials scientists and engineers typically fabricate an array of samples with increasing concentrations of the alloying element in order to build up a gradient of substrates suitable for corrosion testing. The resulting series of substrates can consist of many samples, which can be time consuming to test and hence slow to reveal the effects of the alloying element's concentration. In this work, we present a fast, simple, and reliable methodology on an ideal model system for monitoring the effect of one of the most commonly used alloying elements in Magnesium alloys, aluminum, on magnesium's corrosion behavior using a single Mg-Al diffusion couple sample and the scanning micropipette contact method. The use of ethylene glycol as the solvent was carried out to enhance the stability of the micro electrochemical setup. The corrosion potentials and currents of pure Mg and Al as well as the intermetallic regions were collected using micro polarization measurements without the influence of grain boundaries and inclusion size. Similar measurements performed across the interfacial region of Al diffusion into Mg revealed a threshold value of Al wt% on the corrosion potentials measured. Such methodology proved to be reproducible and therefore is a good way to measure the effects of various alloying elements for any metal in question.

Porous films are ubiquitous in electrochemistry. They frequently form on active electrodes due to the precipitation of insoluble reaction products. They can have beneficial effects, like the protection from electrochemical corrosion, or be of parasitic nature, as in the poisoning of fuel cell air cathodes. The effects of such layers on the electrochemical response of the substrate can be probed by Scanning Electrochemical Microscopy (SECM). Herein, we present modifications to the conventional analytical expressions for SECM microelectrode approach curves, to account for the effects of a porous layer. The modified expressions can be used to fit experimental approach curves and obtain film thickness and porosity parameters. Their performance is demonstrated through comparison to results obtained by finite element modeling, and by fitting experimental approach curves over well-defined filter membranes.

Li-ion batteries that incorporate manganese present several advantages, including low cost and low toxicity. However, these batteries often suffer from dissolution of manganese into the electrolyte solution, severely impeding battery performance. This work describes the quantitative detection of Mn2+ions in battery relevant environment i.e. non-aqueous electrolyte within an inert atmosphere. To this end, an electrochemical probe was fabricated using electrochemical deposition of a Hg cap onto a 25 μm Pt disk microelectrode. The Pt/Hg microelectrode was fully characterized by optical microscopy, cyclic voltammetry, scanning electrochemical microscopy. Using square wave anodic stripping voltammetry to overcome reproducibility issues with classical linear sweep anodic stripping voltammetry, Mn2+was quantified in non-aqueous solution with a limit of detection of 14 μM. Finally, using this detection scheme, the trapping ability of aza-15-crown-5 ether and dilithium iminodiacetate was investigated.