A study on the intrinsic degradation behavior of Fe0.85 TiMn0.15 during hydrogen absorption-desorption cycling

The temperature induced hydrogen absorption-desorption cycling of Fe0.85 TiMn0.15 intermetallic compounds was performed to study the potential applications of alloys as hydrogen storage materials. The deterioration of the hydrogenation properties of Fe0.85 TiMn0.15 during thermally induced hydrogen absorption-desorption cycling was investigated using the thermal desorption of hydrogen and the change in the P-C-T curves as a function of the number of cycles. Thermal cycling of Fe0.85 TiMn0.15 produces an intrinsic degradation that reduces the hydrogen storage capacity and suppresses the formation of the γ phase in its hydride. The mechanism of degradation is probably related to the formation of stable hydrides, which causes a change in the environments of the sites occupied by hydrogen in the neighbor matrix. (Author)