Solid oxide electrochemical systems, such as solid oxide fuel cells (SOFC), solid oxide electrolysis cells (SOEC), and oxygen transport membranes (OTM) enable clean and reliable production of energy or fuel for a range of applications, including, but not limited to, residential, commercial, industrial, and grid-support. These systems utilize solid-state ceramic oxides which offer enhanced stability, fuel flexibility, and high energy conversion efficiency throughout operation. However, the nature of system conditions, such as high temperatures, complex redox atmosphere, and presence of volatile reactive species become taxing on solid oxide materials and limit their viability during long-term operation. Ongoing research efforts to identify the material corrosion and degradation phenomena, as well as discover possible mitigation techniques to extend material efficiency and longevity, is the current focus of the research and industrial community. In this review, degradation processes in select solid oxide electrochemical systems, system components, and comprising materials will be discussed. Overall degradation phenomena are presented and certain degradation mechanisms are discussed. State-of-the-art technologies to mitigate or minimize the above-mentioned degradation processes are presented.

It is known that different diseases have characteristic biomarkers that are secreted very early on, even before the symptoms have developed. Before any kind of therapeutic approach can be used, it is necessary that such biomarkers be detected at a minimum concentration in the bodily fluids. Here, we report the fabrication of an interdigitated sensing device integrated with polyvinyl alcohol (PVA) nanofibers and carbon nanotubes (CNT) for the detection of an inflammatory biomarker, C-reactive protein (CRP). The limit of detection (LOD) was achieved in a range of 100 ng mL⁻¹ and 1 fg mL⁻¹ in both phosphate buffered saline (PBS) and human serum (hs). Furthermore, a significant change in the electrochemical impedance from 45% to 70% (hs) and 38% to 60% (PBS) over the loading range of CRP was achieved. The finite element analysis indicates that a non-redox charge transduction at the solid/liquid interface on the electrode surface is responsible for the enhanced sensitivity. Furthermore, the fabricated biosensor consists of a large electro-active surface area, along with better charge transfer characteristics that enabled improved specific binding with CRP. This was determined both experimentally and from the simulated electrochemical impedance of the PVA nanofiber patterned gold electrode.

This study investigates the influence of electropolymerization time on the evolution of morphology and the electrochemical performance of polypyrrole (PPy) electrodes. The PPy films were synthesized by varying the deposition time from 300 seconds to 1800 seconds, corresponding to 5 to 50 cycles. The electrodes were characterized by Raman spectroscopy, XPS, and SEM, and electrochemical analyses were conducted using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD). Experimental results showed that increasing deposition time yields large cauliflower-like structures, thereby enhancing capacitance. The 50 cycle electrode exhibited the highest specific capacitance of 412 F/g in a three-electrode configuration using 1.2 M KCl aqueous electrolyte. The EIS analysis revealed a low ohmic resistance and increasing non-ohmic resistance with deposition, which may indicate the onset of diffusion-limited behavior. A symmetric PPy supercapacitor assembled using optimized electrodes delivered an energy density (ED) of 10.29 Wh/kg and power density (PD) of 146 W/kg at 0.1 A/g. These findings show that electrodeposition time plays an important role in PPy film growth, ion transport, and the resulting electrochemical performance.

Incorporation of a porous and electrically conducting chromium getter layer, comprising of a mixture of complex metal oxide getter and electrically conducting perovskite phase, has been examined as a cost-effective approach for the capture of gaseous chromium species originating from the metallic interconnect alloys conventionally used in SOFC stacks. Getter layer deposited on the cathode surface or placed away from the cathode, was electrically tested in a half cell configuration (3%H₂O-Air/Pt//YSZ//LSM/Getter/3%H₂O-Air-CrOx) at 850 ºC for 100 hours. Post tested cells were analyzed for composition of reaction products and changes in the morphology. Our observations indicate that getter placed away from the cathode and conductive getter paste deposited on cathode surface successfully capture all chromium incoming with air stream thus mitigating the poisoning of the cathode without performance degradation. The gaseous chromium predominantly concentrated at the impinging getter surface and the bulk electrode and electrode-electrolyte interface remained free of chromium.