A simple, fast, and reproducible method for the fabrication of disk ultramicroelectrodes (UMEs) with controlled geometry is reported. The use of prepulled soda-lime glass capillaries allows one to bypass the irreproducible torch-sealing and experimentally challenging tip-sharpening steps used in conventional fabrication protocols. A micron-sized electroactive wire is sealed inside this capillary producing UMEs with a highly reproducible geometry. Total fabrication time (1 h) and experimental difficulty are significantly reduced. Disk UMEs with various diameters and cores were fabricated, including carbon fiber (7 and 11 μm), gold (10 and 25 μm), platinum (10 and 25 μm), silver (25 μm), and mercury (25 μm). The ratio of the insulating sheath to the electroactive core of the UMEs was 2.5-3.6. Silver UMEs were also used to produce a Ag/AgCl microreference electrode. This general fabrication method can readily be applied to other electroactive cores and could allow any research group to produce high quality disk UMEs, which are a prerequisite for quantitative scanning electrochemical microscopy.

State‐of‐the‐art scanning probe microscopy (SPM) methods as applied to energy conversion and storage devices, specifically lithium‐ion batteries, are reviewed with an emphasis on the electroactive elements. The unique ability of SPM‐based methods to provide localized information has proven highly valuable for the in‐depth understanding of the fundamental mechanisms, processes, and degradation of lithium‐ion batteries (LIBs). As such, SPM analysis is poised to play a strong role in the competition for new higher performing LIBs, especially given the unprecedented choice and availability of SPM techniques tailored to provide physical and chemical information at the nanoscale.

Titanium has been added to ferritic stainless steels to combat the detrimental effects of intergranular corrosion. While this has proven to be a successful strategy, we have found that the resulting Ti-rich inclusions present on the surface play a significant role in the initiation of other forms of localized corrosion. Herein, we report the effect of these inclusions on the localized corrosion of a stainless steel using macro and micro electrochemical techniques. Through the use of scanning electrochemical microscopy, we observe the microgalvanic couple formed between the conductive inclusions and passivated metal matrix. The difference in local reactivity across the material's surface was quantified using a 3D finite element model specifically built to respect the geometry of the corrosion-initiating features. Combined with electron microscopy and micro elemental analysis, localization of other alloying elements has been reported to provide new insight on their significance in localized corrosion resistance.

High-velocity oxygen fuel thermal spray stainless steel coatings are desirable for their excellent erosion resistance. However, the fabrication process can lead to a decrease in corrosion resistance in comparison to the original bulk material. Here we produced stainless steel coatings on stainless steel substrates using varying deposition parameters to investigate the corrosion properties of the resulting composite steels and elucidate the corrosion behavior both on the macro and micro scale. Macro potentiodynamic polarization measurements carried out in corroding environments demonstrated the rate of degradation of the Fe-Cr alloy coating. After short immersion periods, the coatings showed iron-like active corroding behavior and no passivation regions on the anodic branch. Over time, the coating's corrosion behavior began to change to signify similar results to that of pure chromium. Ex-situ electron microscopy and elemental composition revealed a Cr oxide rich layer left on the coating's surface. Micro electrochemical techniques including scanning electrochemical microscopy and scanning micropipette contact method were employed over the coatings and powdered material, respectively, to show that the lack of protective passivity the thermal spray coatings possess is mostly inherited from the atomized powdered stainless steel material.

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