Characterization of Metal Alloy Powder Materials for Metal-Hydride Anodes Using Thin-Layer Electrode Approach

Abstract

A type of small electrode for basic studies on metal alloy powder materials for metal-hydride anodes has been proposed. The electrode holds a few milligrams of the active material and contains no inert binder material admixed to the active material. The electrode is prepared simply in a laboratory mechanical press. It was shown using cyclic voltammetry and electrochemical impedance spectroscopy that the electrode exhibits features of single-particle electrodes. Thus, it is suitable for a direct determination of performance parameters characteristic of the active particles without the need to resort to a complicated porous-electrode modeling.

Low Temperature Characteristics of Hydrogen Storage Alloy LaMm-Ni4.1Al0.3Mn0.4Co0.45 for Ni-MH Batteries

“…The general characteristics of the alloy under ambient conditions (0-30 • C) were reported in our previous reports [24][25][26][27]. The alloy crystallises in hexagonal P6/mmm Cu 5.4 Yb 0.8 lattice [28], which is a modification of the CaCu 5 -type crystal structure adopted by parent LaNi 5 [29], with unit cell: a = b = 5.0079(5) Å, c = 4.0521(4) Å, V = 88.007(16) Å 3 (ICSD number 427242) [24] ( Figure S2).…”

“…The Limited Volume Electrode (LVE) method [30][31][32][33] was adapted to investigate electrochemical behaviour of neat LaMm-Ni 4.1 Al 0.3 Mn 0.4 Co 0.45 alloy ( Figure S1). Pellet electrodes were prepared by high pressure treatment (20 MPa) of the pristine alloy placed between two inert golden mesh current collectors (Good Fellow, 99.99% Au, 0.25 mm) in the same procedure, as described previously [24][25][26][27]34]. No additives or binding materials (e.g., metal powders, graphite, PTFE, PVA) were used, as they could affect the electrochemical characteristics of the investigated material [1,25,[35][36][37][38].…”

“…Pellet electrodes were prepared by high pressure treatment (20 MPa) of the pristine alloy placed between two inert golden mesh current collectors (Good Fellow, 99.99% Au, 0.25 mm) in the same procedure, as described previously [24][25][26][27]34]. No additives or binding materials (e.g., metal powders, graphite, PTFE, PVA) were used, as they could affect the electrochemical characteristics of the investigated material [1,25,[35][36][37][38]. Thus, the results presented in this study may differ from other reports, where the active material being investigated was not pristine.…”

“…A dedicated PTFE sample holder was used in all performed experiments to secure the working electrode, which had a diameter of ca. 1 cm, in three electrode systems ( Figure 1) [24][25][26][27].…”

Electrochemical reduction of La(Ni3.6Co0.7Al0.4Mn0.3) (LaMM) deuterides investigated by in situ neutron powder diffraction: Following the metal-hydride phase transition under technical operating conditions in a KOD electrolyte

“…The metal hydride (MH) alloy was a standard, commercial, AB 5 -type alloy of the composition La(Ni 3.6 Co 0.7 Al 0.4 Mn 0.3 ) (LaMM), which is a so called high Cobalt composition (VARTA, Germany [35]). The particle size was granulated down to below 125 nm and the material has been mixed with teflon and graphite to stabilize the storage alloy to form the electrode pellet.…”