Evaluation of electrochemical hydrogenation and corrosion behavior of LaNi5-based materials using galvanostatic charge/discharge measurements

Bala, H.; Kukuła, I.; Giza, K.; Marciniak, Bernard; Różycka‐Sokołowska, Ewa; Drulis, H.

doi:10.1016/j.ijhydene.2012.07.126

Cited by 38 publications

(20 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resulting hydrogen transport in powdered, composite material (hydrogen diffusivity) can be characterized by the effective diffusion coefficient (D H ), which takes on values of the order of 10 [5,8,9]. The effective hydrogen diffusivity increases with the increase of easy paths of diffusion and decreases with particle oxidation, so it changes with electrode cycling [10][11][12]. For the first cycles, D H usually increases because of an increase in material porosity.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…As it is known [12,22], the real active surface of porous composite electrode increases with time and with cycle number. Long-lasting cycling, however, causes corrosion effects and generation of material oxide phases (e.g., NiO) on material particles [10][11][12], which decreases the effective electrode surface. It has been shown in [22] that for LaNi 5 particles of mean radius 0.0018 cm, the real initial effective surface of the composite pellet (containing 0.040 g of active material) was approximately 17 times greater than the geometric area of the final electrode.…”

Section: Introductionmentioning

confidence: 99%

“…It has been shown in [22] that for LaNi 5 particles of mean radius 0.0018 cm, the real initial effective surface of the composite pellet (containing 0.040 g of active material) was approximately 17 times greater than the geometric area of the final electrode. This efficient material surface area distinctly increases with cycling owing to further material pulverization (particularly for some first cycles [10][11][12]23]). As a consequence, the hydrogen diffusion coefficient in Eq.…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, to ensure constant and maximal concentration of H atoms in the material, the long-lasting charging and low electrode thickness are required. Moreover, the electrochemical capacity of the LaNi 5 -based electrodes depends on many electrochemical factors like charge rate, cycle number, external pressure and temperature [4,6,[10][11][12].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Hydrogen diffusivity in the massive LaNi5 electrode using voltammetry technique

Dymek

Bala

2013

J Solid State Electrochem

View full text Add to dashboard Cite

The Randles-Sevčik relationship has been applied to evaluate atomic hydrogen diffusivity in massive LaNi 5 intermetallic compound. The electrode was cathodically hydrogenated in 6 M KOH solution (22°C), and then voltammetry measurements were carried out at various, very slow potential scan rates (υ =0.01-0.1 mV·s −1). At potentials more noble than the equilibrium potential of the H 2 O/H 2 system, the anodic peaks were registered as a consequence of oxidation of hydrogen absorbed in cathodic range. The peak potentials linearly increase with the logarithm of the scan rate with a slope of 0.059 V. The slope testifies to a symmetric charge transfer process with symmetry factor α =½. The peak currents linearly increase with the square root of the potential scan rate, and the straight line runs through the origin of the coordinate system. The slope of the I a (peak) =f(υ 1/2 ) straight line is a measure of the atomic hydrogen diffusion coefficient. Assuming the hydrogen concentration in the LaNi 5 material after cathodic exposure to be C 0,H =0.071 mol·cm −3 (63 % of theoretical value), the hydrogen diffusion coefficient equals D H =2.0· 10 −9 cm 2 s −1. Extrapolation of rectilinear segments of potentiodynamic polarization curves with Tafel slopes of 0.12 V and linear polarization dependencies from voltammetry tests allowed the exchange current densities of the H 2 O/H 2 system on the tested material to be determined. The exchange current densities on initially hydrogenated LaNi 5 alloy are close to 1 mA·cm −2

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Hydrogen diffusivity in the massive LaNi5 electrode using voltammetry technique

Dymek

Bala

2013

J Solid State Electrochem

View full text Add to dashboard Cite

show abstract

Electrochemical properties of the CaNi _{5−
x} Mn _x electrodes synthesized by mechanical alloying

et al. 2020

View full text Add to dashboard Cite

In this article, we exhaustively examined the effects of Mn substitution for Ni on the structures and electrochemical characterization of the CaNi 5−x Mn x (x = 0.2, 0.3, 0.5, 1) alloys prepared by mechanical synthesis for 40 hours at ball to powder weight ratio of 8:1. The characterization of electrodes was examined by X-ray diffraction, scanning electron microscope and electrochemical tests. In this context, the structural properties for each alloy have two major phases Ni, Ca 2 Ni 7 ; Ni, CaNi 3 ; Ni, CaNi 5 ; Ni, CaNi 3 where x = 0.2, 0.3, 0.5 and 1 respectively. The powder micrograph shows the existence of agglomerates has average particle size between 22 and 35 μm. In addition, the quantification by energy dispersive spectroscopy has been indicated the chemical composition of the all produced alloys is near their nominal composition. All electrodes are activated during the first cycle, independent of the Mn substitution rate. The highest values of discharge capacity and reversibility are obtained for x = 0.3 (125 mAh g −1 , 0.17 V) and x = 0.5 (119 mAh g −1 , 0.19 V) despite their low cycle stability. The evolution of D H /a 2 ratio and the I 0 exchange current density for the different Mn substitution rates is in accordance with that of the evolution of discharge capacities. The better kinetic properties is observed for x = 0.5 during electrochemical cycling.

show abstract

Hydrogen diffusivity, kinetics of H2O/H2 charge transfer and corrosion properties of LaNi5-powder, composite electrodes in 6 M KOH solution

Bala

Dymek

Adamczyk

et al. 2013

J Solid State Electrochem

View full text Add to dashboard Cite

Evaluation of electrochemical hydrogenation and corrosion behavior of LaNi5-based materials using galvanostatic charge/discharge measurements

Cited by 38 publications

References 13 publications

Hydrogen diffusivity in the massive LaNi5 electrode using voltammetry technique

Hydrogen diffusivity in the massive LaNi5 electrode using voltammetry technique

Electrochemical properties of the CaNi _{5−
x} Mn _x electrodes synthesized by mechanical alloying

Hydrogen diffusivity, kinetics of H2O/H2 charge transfer and corrosion properties of LaNi5-powder, composite electrodes in 6 M KOH solution

Contact Info

Product

Resources

About

Evaluation of electrochemical hydrogenation and corrosion behavior of LaNi5-based materials using galvanostatic charge/discharge measurements

Cited by 38 publications

References 13 publications

Hydrogen diffusivity in the massive LaNi5 electrode using voltammetry technique

Hydrogen diffusivity in the massive LaNi5 electrode using voltammetry technique

Electrochemical properties of the CaNi 5− x Mn x electrodes synthesized by mechanical alloying

Hydrogen diffusivity, kinetics of H2O/H2 charge transfer and corrosion properties of LaNi5-powder, composite electrodes in 6 M KOH solution

Contact Info

Product

Resources

About

Electrochemical properties of the CaNi _{5−
x} Mn _x electrodes synthesized by mechanical alloying