Nanometer-spaced electrodes with calibrated separation

We have fabricated pairs of platinum electrodes with separation between 20 and 3.5 nm. Our technique combines electron beam lithography and chemical electrodeposition. We show that the measurement of the conductance between the two electrodes through the electrolyte provides an accurate and reproducible way to control their separation. We have...

Diffusion Impedance on Nickel/Gadolinia-Doped Ceria Anodes for Solid Oxide Fuel Cells

Electrochemical impedance measurements were carried out on symmetrical nickel/gadolinia-doped ceria test cells. For H2, N2, and H2O mixtures, the diffusion length obtained based on the impedance measurements is on the order of centimeters. This high value of the diffusion length is attributed to the flow field in the reactor. It is suggested...

Electrowinning Al from Al2S3 in Molten Salt

In order to investigate an alternative process for the production of primary aluminum via a sulfide intermediate, the electrochemical behavior of Al2S3 in molten salt has been studied on a laboratory scale. The effects of electrolyte composition, temperature, and cell design on the cell performance have been investigated. Temperature and...

Corrosion Performance of Carbon Steel in Simulated Pore Solution in the Presence of Micelles

This study presents the results on the investigation of the corrosion behavior of carbon steel in model alkaline medium in the presence of very low concentration of polymeric nanoaggregates [0.0024 wt % polyethylene oxide (PEO)113-b-PS70 micelles]. The steel electrodes were investigated in chloride free and chloride-containing cement extracts....

The Role of Coherency Strains on Phase Stability in LixFePO4: Needle Crystallites Minimize Coherency Strain and Overpotential

We investigate the role of coherency strains on the thermodynamics of two-phase coexistence during Li (de)intercalation of LixFePO4. We explicitly account for the anisotropy of the elastic moduli and analytically derive coupled chemical and mechanical equilibrium criteria for two-phase morphologies observed experimentally. Coherent two-phase...

Impact of Biomass-Derived Contaminants on SOFCs with Ni/Gadolinia-Doped Ceria Anodes

The impact of biomass-derived contaminants on solid-oxide fuel cells (SOFCs) with Ni/gadolinia-doped ceria (GDC) anodes was investigated using electrochemical impedance analysis. Measurements were carried out with symmetric test cells under a single-gas atmosphere. The impact of H2S, HCl, and naphthalene in the gas stream on the performance of...

Impedance Simulation of a Li-Ion Battery with Porous Electrodes and Spherical Li+ Intercalation Particles

We present a semimathematical model for the simulation of the impedance spectra of a rechargeable lithium batteries consisting of porous electrodes with spherical Li+ intercalation particles. The particles are considered to have two distinct homogeneous phases as a result of the intercalation and deintercalation of Li+ during charge and...