Formation of LaNi5 Hydrogen Storage Alloy by Electrodeposition of La Using Molten Salt

A hydrogen storage alloy was formed by electrodepositing La using a molten salt. La was electrodeposited using Ni as a substrate in NaCl-KCl-5.0 mol% LaF3 molten salt at electrodeposition temperatures of 750 degrees C and 900 degrees C. The electrodeposition potential was -2.25 V. The LaNi5 hydrogen storage alloy was then prepared by the electrodeposition of La and the mutual diffusion of the Ni substrate. As a result, it was clarified that La can be electrodeposited by using a molten salt. Single-phase LaNi5 was produced at 750 degrees C rather than at 900 degrees C. It became possible to uniformly form LaNi5, an intermetallic compound, on the substrate surface. The prepared hydrogen storage alloy was exposed to Ar-10%H-2 to store hydrogen; at this time, hydrogen was stored by changing the sample temperature. The discharged hydrogen was measured by a gas sensor. It was clarified that the hydrogen storage and hydrogen discharge were the highest in the sample obtained by electrodepositing La for 1 h at 750 degrees C. LaNi5 formed by electrodeposition showed hydrogen storage properties, and this method was found to be effective even for samples with complex shapes.

Automated summary

LaNi5 hydrogen storage alloy was successfully prepared by electrodepositing La using a molten salt. Uniform formation of LaNi5 on the substrate surface was achieved at 750 degrees C. The electrodeposition-formed LaNi5 exhibited good hydrogen storage properties.