The hydrogen evolution reaction (HER) on Ni in alkaline media was investigated by scanning electrochemical microscopy under two operating modes. First, the substrate generation/tip collection mode was employed to extract the "true" cathodic current associated with the HER from the total current in the polarization curve. Compared to metallic Ni, the electrocatalytic activity of the HER is impro...

Impedance spectra of the hydrogen evolution reaction, HER, at low cathodic overpotentials were analyzed on the basis of the theoretical admittance/frequency function, initially derived for the Volmer-Heyrovsky-Tafel reaction mechanism involving the hydrogen insertion (absorption + diffusion) step. General principles of the impedance spectroscopy for HER are discussed using schematically constru...

The Al-air battery possesses high theoretical specific energy (4140 W h/kg) and is therefore an attractive candidate for vehicle propulsion. However, the experimentally observed open-circuit potential is much lower than what bulk thermodynamics predicts, and this potential loss is typically attributed to corrosion. Similarly, large Tafel slopes associated with the battery are assumed to be due ...

Electrocatalytic activity for the hydrogen evolution reaction on Ni–Co–LaNi5 composite electrodes prepared by electrochemical codeposition technique was evaluated. The relationship between the current density for hydrogen evolution reaction and the amount of LaNi5 particles in Ni–Co baths is like the well-known “volcano plot”. The Surface morphology and microstructure of Ni–Co–LaNi5 coatings we...

We present a large family of Spin(p, q)-valued discrete spectral problems. The associated discrete nets generated by the so called Sym-Tafel formula are circular nets (i.e., all elementary quadrilaterals are inscribed into circles). These nets are discrete analogues of smooth multidimensional immersions in R including isothermic surfaces, Guichard nets, and some other families of orthogonal net...

By means of linear polarization, Tafel polarization and galvanostatic discharge methods, the kinetic properties of MlNi4.3ÿXCoXAl0.7 (X=0.0, 0.3, 0.5, 0.7, 0.9, 1.1 and 1.3) hydride electrodes, including high rate dischargeability HRD, exchange current density I0, limiting current density IL, the symmetry factor b, and the apparent di€usion coecient of hydrogen in the a phase Da have been stud...

A synergistic co-doping strategy is proposed to identify a series of BaCo0.9-x Fe x Sn0.1O3-δ perovskites with tunable electrocatalytic activity for the oxygen evolution reaction (OER). Simply through tailoring the relative concentrations of less OER-active tin and iron dopants, a cubic perovskite structure (BaCo0.7Fe0.2Sn0.1O3-δ) is stabilized, showing intrinsic OER activity >1 order of magnit...

Using a novel electrochemical phase-field model, we question the common belief that Li(X)FePO(4) nanoparticles always separate into Li-rich and Li-poor phases during battery discharge. For small currents, spinodal decomposition or nucleation leads to moving phase boundaries. Above a critical current density (in the Tafel regime), the spinodal disappears, and particles fill homogeneously, which ...