Speaker
Description
Hydrogen storage poses challenges in the hydrogen economy due to its low density. Titanium-iron (TiFe) alloys are promising for ambient-condition storage, reversibly absorbing hydrogen at room temperatures with volumetric capacities comparable to liquid H2 (~100 kgH2 m-3) [1]. However, low gravimetric capacity and oxide formation limit TiFe’s standalone use. Elemental doping and mechanical processing have been proposed to address these issues. Theoretical studies suggest transition element dopants (e.g., Cr, V, Nb, Mn) enhance TiFe’s hydrogen storage by altering lattice size and strain, facilitating H2 diffusion [2]. Limited research exists on TiFe doped with Ta, Nb [3,4] and correlations between crystallographic structure and storage properties remain unclear.
In this work, V- and Nb-doped TiFe alloys with varying stoichiometries were synthesized via vacuum arc melting (VAM). Structural characterization via PXRD and EXAFS revealed high agreement between refined crystallographic parameters. Pressure-composition-temperature (PCT) measurements demonstrated improved activation and kinetics with precise doping, linking dopant-induced lattice occupancy to hydrogen absorption. These findings advance mechanistic insights into transition-metal-doped TiFe for optimized storage.
References
(1) An overview on TiFe intermetallic for solid-state hydrogen storage: microstructure, hydrogenation, and fabrication processes G. K. Sujan, Zengxi Pan, Huijun Li, Daniel Liang & Nazmul Alam.
(2) Influence of substitutional impurities on hydrogen diffusion in B2-TiFe alloy, A.V. Bakulin a,b,, S.S. Kulkov a,b, S.E. Kulkova a,b, S. Hocker c, S. Schmauder c.
(3) Formation of a bimodal structure in ultrafine Ti–Fe–Nb alloys with high-strength and enhanced ductility G.H. Cao a,n, Y.F.Peng a, N.Liu a, X.Li a, Z.S.Lei a, Z.M.Ren a, D.Gerthsen b, A.M.Russell c,d.
(4) Hydrogen storage properties of TiFe-based ternary mechanical alloys with cobalt and niobium. A thermochemical approach E.A. Berdonosova a, V.Yu. Zadorozhnyy b,c, M.Yu. Zadorozhnyy b, K.V. Geodakian a, M.V. Zheleznyi b, A.A. Tsarkov b, S.D. Kaloshkin b, S.N. Klyamkin a,.
