Stress reduction in a hydride container by the addition of a glidant agent

Abstract

Hydrogen absorbing materials, such as metal hydrides, present a possible solution for hydrogen storage. During the absorption process these materials swell, which can put the mechanical integrity of its container at risk. One possibility is to increase the flowability of the absorbing material, usually a fine cohesive powder, so that it can rearrange within its container during the swelling stage. In this work, we study if this rearrangement could be improved by the addition of Aerosil, a type of colloidal silica widely used as glidant agent. The walls of a stainless steel reactor are instrumented with strain gauges to measure the accumulation of stresses due to hydrogen absorption-desorption cycles. We explore the container filled with pure LaNi5 absorbing material previously activated, so as with different Aerosil-added proportions. Results show that Aerosil allows avoiding stress build-up, for all glidant concentrations used in present study.